93 results on '"Somers MJ"'
Search Results
2. South Africa’s newly approved marine protected areas have increased the protected modelled habitat of nine odontocete species
- Author
-
Purdon, J, primary, Shabangu, F, additional, Pienaar, M, additional, Somers, MJ, additional, and Findlay, KP, additional
- Published
- 2020
- Full Text
- View/download PDF
3. IgG antineutrophil cytoplasmic antibodies in IgA nephropathy: A clinical variant?
- Author
-
Ramirez, SB, primary, Rosen, S, additional, Niles, J, additional, and Somers, MJ, additional
- Published
- 1998
- Full Text
- View/download PDF
4. Fluid overload and mortality in children receiving continuous renal replacement therapy: the prospective pediatric continuous renal replacement therapy registry.
- Author
-
Sutherland SM, Zappitelli M, Alexander SR, Chua AN, Brophy PD, Bunchman TE, Hackbarth R, Somers MJ, Baum M, Symons JM, Flores FX, Benfield M, Askenazi D, Chand D, Fortenberry JD, Mahan JD, McBryde K, Blowey D, and Goldstein SL
- Abstract
BACKGROUND: Critically ill children with hemodynamic instability and acute kidney injury often develop fluid overload. Continuous renal replacement therapy (CRRT) has emerged as a favored modality in the management of such children. This study investigated the association between fluid overload and mortality in children receiving CRRT. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: 297 children from 13 centers across the United States participating in the Prospective Pediatric CRRT Registry. PREDICTOR: Fluid overload from intensive care unit (ICU) admission to CRRT initiation, defined as a percentage equal to (fluid in [L] - fluid out [L])/(ICU admit weight [kg]) x 100%. OUTCOME & MEASUREMENTS: The primary outcome was survival to pediatric ICU discharge. Data were collected regarding demographics, CRRT parameters, underlying disease process, and severity of illness. RESULTS: 153 patients (51.5%) developed < 10% fluid overload, 51 patients (17.2%) developed 10%-20% fluid overload, and 93 patients (31.3%) developed > or = 20% fluid overload. Patients who developed > or = 20% fluid overload at CRRT initiation had significantly higher mortality (61/93; 65.6%) than those who had 10%-20% fluid overload (22/51; 43.1%) and those with < 10% fluid overload (45/153; 29.4%). The association between degree of fluid overload and mortality remained after adjusting for intergroup differences and severity of illness. The adjusted mortality OR was 1.03 (95% CI, 1.01-1.05), suggesting a 3% increase in mortality for each 1% increase in severity of fluid overload. When fluid overload was dichotomized to > or = 20% and < 20%, patients with > or = 20% fluid overload had an adjusted mortality OR of 8.5 (95% CI, 2.8-25.7). LIMITATIONS: This was an observational study; interventions were not standardized. The relationship between fluid overload and mortality remains an association without definitive evidence of causality. CONCLUSIONS: Critically ill children who develop greater fluid overload before initiation of CRRT experience higher mortality than those with less fluid overload. Further goal-directed research is required to accurately define optimal fluid overload thresholds for initiation of CRRT. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
5. Case records of the Massachusetts General Hospital. Case 23-2009. A 13-year-old boy with headache, nausea, seizures, and hypertension.
- Author
-
Somers MJ, Sharma A, Grant PE, Guimaraes AR, Schneeberger EE, Somers, Michael J G, Sharma, Amita, Grant, P Ellen, Guimaraes, Alexander R, and Schneeberger, Eveline E
- Published
- 2009
- Full Text
- View/download PDF
6. Case 11-2004: a boy with rash, edema, and hypertension.
- Author
-
Somers MJ, Daouk GH, and McCluskey RT
- Published
- 2004
7. The influence of occupational image subculture on job attitude-job performance relationship.
- Author
-
Birnbaum D and Somers MJ
- Published
- 1986
- Full Text
- View/download PDF
8. Ecomorphological Disparity of Small Carnivore Guilds
- Author
-
Carlo Meloro, Do Linh San, E, Sato, JJ, Belant, JL, and Somers, MJ
- Subjects
QH301 ,GE - Abstract
Mammalian species composition might change in relation to biotic or abiotic factors depending on the scale of investigation. Ecomorphology is one of the tools that can be employed to understand how species composition changes through space and time. Here, the morphological diversity of small carnivore guilds (defined as a pool of carnivoran species whose body mass is < 7 kg) is explored using 2D geometric morphometrics of mandibles belonging to 61 species. A strong taxonomic signal emerges by looking at mandibular morphospace so that separation of carnivoran families is apparent. Mustelids are the most distinct, being characterized by a short and curved mandibular corpus, while felids exhibit a typical hypercarnivore mandible with no crushing molar area. Overlap occurs between canids, viverrids, and herpestids possibly in relation to their generalized feeding habits and killing behaviours. When species are grouped according to their presence/absence into six carnivoran species-rich ecosystems, an ecogeographical pattern occurs. Guilds from higher latitudes such as Yellowstone (USA) and Krokonose (Europe) together with the Kruger (South Africa) assemblage are highly depleted of mandibular morphotypes. In contrast, guilds from tropical areas (Gunung Lensung, Indonesia; Yasuni, Ecuador; and La Amistad, Panama) exhibit high diversity of mandibular shapes corresponding to higher values of morphological disparity. This latter parameter correlates positively with precipitation variables, supporting a strong influence of climate on the historical community assembly of small carnivore guilds. Clearly, small carnivores can play a key role in ecosystem functioning and more theoretical work is needed to better identify this at multiple spatial and temporal scales.
9. Water provisioning shapes carnivore community structure.
- Author
-
Somers MJ and Walters M
- Abstract
Water provisioning is common in arid and semi-arid African ecosystems, but its effects on carnivore communities are not understood. Recently, Morin et al. documented the unexpectedly contrasting space-use patterns of dominant and subordinate carnivores around water sources, with dominant carnivores facilitating subordinate carnivores., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
10. Consent to advanced imaging in antenatal pulmonary embolism diagnostics: Prevalence, outcomes of nonconsent and opportunities to mitigate delayed diagnosis risk.
- Author
-
Vinson DR, Somers MJ, Qiao E, Campbell AR, Heringer GV, Florio CJ, Zekar L, Middleton CE, Woldemariam ST, Gupta N, Poth LS, Reed ME, Roubinian NH, Raja AS, and Sperling JD
- Abstract
Background: Nonconsent to pulmonary vascular (or advanced) imaging for suspected pulmonary embolism (PE) in pregnancy can delay diagnosis and treatment, increasing risk of adverse outcomes. We sought to understand factors associated with consent and understand outcomes after nonconsent., Methods: This retrospective cohort study was undertaken across 21 community hospitals from October 1, 2021, through March 31, 2023. We included gravid patients undergoing diagnostics for suspected PE who were recommended advanced imaging. The primary outcome was verbal consent to advanced imaging. Diagnostic settings were nonobstetric (99% emergency departments [EDs]) and obstetrics (labor and delivery and outpatient clinics). Using quasi-Poisson regression, we calculated adjusted relative risks (aRRs) of consenting with 95% confidence intervals (CIs). We also reported symptom resolution and delayed imaging at follow-up and 90-day PE outcomes., Results: Imaging was recommended for 405 outpatients: median age was 30.5 years; 50% were in the third trimester. Evaluation was more common in nonobstetric (83%) than obstetric settings (17%). Overall, 314 (78%) agreed to imaging and 91 (22%) declined imaging. Consenting was more prevalent in obstetric settings compared with nonobstetric settings: 99% versus 73% (p < 0.001). When adjusted for demographic and clinical variables, including pretest probability, only obstetric setting was independently associated with consenting: aRR 1.26 (95% CI 1.09-1.44). Seventy-nine (87%) patients declining imaging had 30-day follow-up. Eight of 12 who reported persistent or worsening symptoms on follow-up were again recommended advanced imaging and consented. Imaging was negative. None who initially declined imaging were diagnosed with PE or died within 90 days., Conclusions: One in five gravid patients suspected of PE declined advanced imaging, more commonly in nonobstetric (principally ED) settings than obstetric settings. Patients symptomatic on follow-up responded favorably to subsequent imaging recommendations without 90-day outcomes. Improving the communication and documentation of informed consent and securing close follow-up for nonconsenters may mitigate risks of missed and delayed PE diagnosis., (© 2024 Society for Academic Emergency Medicine.)
- Published
- 2024
- Full Text
- View/download PDF
11. In reply.
- Author
-
Casey SD, Zekar L, Somers MJ, Westafer LM, Reed ME, and Vinson DR
- Published
- 2024
- Full Text
- View/download PDF
12. Using the multivariate Hawkes process to study interactions between multiple species from camera trap data.
- Author
-
Nicvert L, Donnet S, Keith M, Peel M, Somers MJ, Swanepoel LH, Venter J, Fritz H, and Dray S
- Subjects
- Animals, Herbivory, Antelopes
- Abstract
Interspecific interactions can influence species' activity and movement patterns. In particular, species may avoid or attract each other through reactive responses in space and/or time. However, data and methods to study such reactive interactions have remained scarce and were generally limited to two interacting species. At this time, the deployment of camera traps opens new opportunities but adapted statistical techniques are still required to analyze interaction patterns with such data. We present the multivariate Hawkes process (MHP) and show how it can be used to analyze interactions between several species using camera trap data. Hawkes processes use flexible pairwise interaction functions, allowing us to consider asymmetries and variations over time when depicting reactive temporal interactions. After describing the theoretical foundations of the MHP, we outline how its framework can be used to study interspecific interactions with camera trap data. We design a simulation study to evaluate the performance of the MHP and of another existing method to infer interactions from camera trap-like data. We also use the MHP to infer reactive interactions from real camera trap data for five species from South African savannas (impala Aepyceros melampus, greater kudu Tragelaphus strepsiceros, lion Panthera leo, blue wildebeest Connochaetes taurinus and Burchell's zebra Equus quagga burchelli). The simulation study shows that the MHP can be used as a tool to benchmark other methods of interspecific interaction inference and that this model can reliably infer interactions when enough data are considered. The analysis of real data highlights evidence of predator avoidance by prey and herbivore-herbivore attraction. Lastly, we present the advantages and limits of the MHP and discuss how it can be improved to infer attraction/avoidance patterns more reliably. As camera traps are increasingly used, the multivariate Hawkes process provides a promising framework to decipher the complexity of interactions structuring ecological communities., (© 2024 The Ecological Society of America.)
- Published
- 2024
- Full Text
- View/download PDF
13. The bii4africa dataset of faunal and floral population intactness estimates across Africa's major land uses.
- Author
-
Clements HS, Do Linh San E, Hempson G, Linden B, Maritz B, Monadjem A, Reynolds C, Siebert F, Stevens N, Biggs R, De Vos A, Blanchard R, Child M, Esler KJ, Hamann M, Loft T, Reyers B, Selomane O, Skowno AL, Tshoke T, Abdoulaye D, Aebischer T, Aguirre-Gutiérrez J, Alexander GJ, Ali AH, Allan DG, Amoako EE, Angedakin S, Aruna E, Avenant NL, Badjedjea G, Bakayoko A, Bamba-Kaya A, Bates MF, Bates PJJ, Belmain SR, Bennitt E, Bradley J, Brewster CA, Brown MB, Brown M, Bryja J, Butynski TM, Carvalho F, Channing A, Chapman CA, Cohen C, Cords M, Cramer JD, Cronk N, Cunneyworth PMK, Dalerum F, Danquah E, Davies-Mostert HT, de Blocq AD, De Jong YA, Demos TC, Denys C, Djagoun CAMS, Doherty-Bone TM, Drouilly M, du Toit JT, Ehlers Smith DA, Ehlers Smith YC, Eiseb SJ, Fashing PJ, Ferguson AW, Fernández-García JM, Finckh M, Fischer C, Gandiwa E, Gaubert P, Gaugris JY, Gibbs DJ, Gilchrist JS, Gil-Sánchez JM, Githitho AN, Goodman PS, Granjon L, Grobler JP, Gumbi BC, Gvozdik V, Harvey J, Hauptfleisch M, Hayder F, Hema EM, Herbst M, Houngbédji M, Huntley BJ, Hutterer R, Ivande ST, Jackson K, Jongsma GFM, Juste J, Kadjo B, Kaleme PK, Kamugisha E, Kaplin BA, Kato HN, Kiffner C, Kimuyu DM, Kityo RM, Kouamé NG, Kouete T M, le Roux A, Lee ATK, Lötter MC, Lykke AM, MacFadyen DN, Macharia GP, Madikiza ZJK, Mahlaba TAM, Mallon D, Mamba ML, Mande C, Marchant RA, Maritz RA, Markotter W, McIntyre T, Measey J, Mekonnen A, Meller P, Melville HI, Mganga KZ, Mills MGL, Minnie L, Missoup AD, Mohammad A, Moinde NN, Moise BFE, Monterroso P, Moore JF, Musila S, Nago SGA, Namoto MW, Niang F, Nicolas V, Nkenku JB, Nkrumah EE, Nono GL, Norbert MM, Nowak K, Obitte BC, Okoni-Williams AD, Onongo J, O'Riain MJ, Osinubi ST, Parker DM, Parrini F, Peel MJS, Penner J, Pietersen DW, Plumptre AJ, Ponsonby DW, Porembski S, Power RJ, Radloff FGT, Rambau RV, Ramesh T, Richards LR, Rödel MO, Rollinson DP, Rovero F, Saleh MA, Schmiedel U, Schoeman MC, Scholte P, Serfass TL, Shapiro JT, Shema S, Siebert SJ, Slingsby JA, Sliwa A, Smit-Robinson HA, Sogbohossou EA, Somers MJ, Spawls S, Streicher JP, Swanepoel L, Tanshi I, Taylor PJ, Taylor WA, Te Beest M, Telfer PT, Thompson DI, Tobi E, Tolley KA, Turner AA, Twine W, Van Cakenberghe V, Van de Perre F, van der Merwe H, van Niekerk CJG, van Wyk PCV, Venter JA, Verburgt L, Veron G, Vetter S, Vorontsova MS, Wagner TC, Webala PW, Weber N, Weier SM, White PA, Whitecross MA, Wigley BJ, Willems FJ, Winterbach CW, and Woodhouse GM
- Subjects
- Animals, Biodiversity, Mammals, Vertebrates, Plants, Africa, Conservation of Natural Resources, Ecosystem
- Abstract
Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species' population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate 'intactness scores': the remaining proportion of an 'intact' reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region's major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
14. Clinical course and management of children with IgA vasculitis with nephritis.
- Author
-
Stone HK, Mitsnefes M, Dickinson K, Burrows EK, Razzaghi H, Luna IY, Gluck CA, Dixon BP, Dharnidharka VR, Smoyer WE, Somers MJ, Flynn JT, Furth SL, Bailey C, Forrest CB, Denburg M, and Nehus E
- Subjects
- Humans, Child, Immunoglobulin A, Disease Progression, IgA Vasculitis complications, IgA Vasculitis diagnosis, IgA Vasculitis drug therapy, Nephritis etiology, Renal Insufficiency, Chronic complications
- Abstract
Background: IgA vasculitis is the most common vasculitis in children and is often complicated by acute nephritis (IgAVN). Risk of chronic kidney disease (CKD) among children with IgAVN remains unknown. This study aimed to describe the clinical management and kidney outcomes in a large cohort of children with IgAVN., Methods: This observational cohort study used the PEDSnet database to identify children diagnosed with IgAV between January 1, 2009, and February 29, 2020. Demographic and clinical characteristics were compared among children with and without kidney involvement. For children followed by nephrology, clinical course, and management patterns were described. Patients were divided into four categories based on treatment: observation, renin-angiotensin-aldosterone system (RAAS) blockade, corticosteroids, and other immunosuppression, and outcomes were compared among these groups., Results: A total of 6802 children had a diagnosis of IgAV, of whom 1139 (16.7%) were followed by nephrology for at least 2 visits over a median follow-up period of 1.7 years [0.4,4.2]. Conservative management was the most predominant practice pattern, consisting of observation in 57% and RAAS blockade in 6%. Steroid monotherapy was used in 29% and other immunosuppression regimens in 8%. Children receiving immunosuppression had higher rates of proteinuria and hypertension compared to those managed with observation (p < 0.001). At the end of follow-up, 2.6 and 0.5% developed CKD and kidney failure, respectively., Conclusions: Kidney outcomes over a limited follow-up period were favorable in a large cohort of children with IgAV. Immunosuppressive medications were used in those with more severe presentations and may have contributed to improved outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
15. Why humans kill animals and why we cannot avoid it.
- Author
-
Allen BL, Bobier C, Dawson S, Fleming PJS, Hampton J, Jachowski D, Kerley GIH, Linnell JDC, Marnewick K, Minnie L, Muthersbaugh M, O'Riain MJ, Parker D, Proulx G, Somers MJ, and Titus K
- Subjects
- Animals, Humans, Animal Welfare, Agriculture, Endangered Species, Animals, Domestic, Animals, Wild
- Abstract
Killing animals has been a ubiquitous human behaviour throughout history, yet it is becoming increasingly controversial and criticised in some parts of contemporary human society. Here we review 10 primary reasons why humans kill animals, discuss the necessity (or not) of these forms of killing, and describe the global ecological context for human killing of animals. Humans historically and currently kill animals either directly or indirectly for the following reasons: (1) wild harvest or food acquisition, (2) human health and safety, (3) agriculture and aquaculture, (4) urbanisation and industrialisation, (5) invasive, overabundant or nuisance wildlife control, (6) threatened species conservation, (7) recreation, sport or entertainment, (8) mercy or compassion, (9) cultural and religious practice, and (10) research, education and testing. While the necessity of some forms of animal killing is debatable and further depends on individual values, we emphasise that several of these forms of animal killing are a necessary component of our inescapable involvement in a single, functioning, finite, global food web. We conclude that humans (and all other animals) cannot live in a way that does not require animal killing either directly or indirectly, but humans can modify some of these killing behaviours in ways that improve the welfare of animals while they are alive, or to reduce animal suffering whenever they must be killed. We encourage a constructive dialogue that (1) accepts and permits human participation in one enormous global food web dependent on animal killing and (2) focuses on animal welfare and environmental sustainability. Doing so will improve the lives of both wild and domestic animals to a greater extent than efforts to avoid, prohibit or vilify human animal-killing behaviour., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
16. CA FIRST (California Febrile Infant Risk Stratification Tool) Algorithm Development in a Learning Health System.
- Author
-
Greenhow TL, Nguyen TH, Young BR, Somers MJ, Huang J, Alabaster A, Vinson DR, Mark DG, Van Winkle PJ, Sharp AL, Reed ME, Shan J, Zhang JY, Rauchwerger AS, and Ballard DW
- Subjects
- Infant, Humans, Child, Retrospective Studies, Reactive Oxygen Species, Fever microbiology, California, Risk Assessment, Algorithms, Learning Health System
- Abstract
Introduction There is considerable variation in the approach to infants presenting to the emergency department (ED) with fever. The authors' primary aim was to develop a robust set of algorithms using community ED data to inform modifications of broader clinical guidance. Methods The authors report the development of California Febrile Infant Risk Stratification Tool (CA FIRST) using key components of the Roseville Protocol (ROS) and American Academy of Pediatrics (AAP) Clinical Practice Guideline (CPG). Expanded guidance was derived using a retrospective analysis of a cohort of 3527 febrile infants aged 7-90 days presenting to any Kaiser Permanente Northern California ED between 2010 and 2019 who underwent a core febrile infant evaluation. Results Melding ROS and AAP CPG algorithms in infants 7-60 days old, CA FIRST Algorithms had comparable performance characteristics to ROS and AAP CPG. CA FIRST enhancements included guidance on febrile infants 61-90 days old, high-risk infants, infants with bronchiolitis, and infants who received immunizations within the prior 48 hours. This retrospective analysis revealed that of 235 febrile infants 22-90 days old with respiratory syncytial virus and 221 who had fever in the 48 hours following vaccination, there were no cases of invasive bacterial infection. Discussion CA FIRST is a set of 13 algorithms providing a thoughtful and flexible approach to the febrile infant while minimizing unnecessary interventions. Conclusions CA FIRST Algorithms empower clinicians to manage most febrile infants. Algorithms are being modified as new data become available, imparting useful and ever-current educational information within a learning health care system., Competing Interests: Conflicts of Interest None declared
- Published
- 2023
- Full Text
- View/download PDF
17. Bilateral Emboli and Highest Heart Rate Predict Hospitalization of Emergency Department Patients With Acute, Low-Risk Pulmonary Embolism.
- Author
-
Casey SD, Zekar L, Somers MJ, Westafer LM, Reed ME, and Vinson DR
- Subjects
- Adult, Humans, Heart Rate, Retrospective Studies, Emergency Service, Hospital, Hospitalization, Pulmonary Embolism
- Abstract
Study Objective: Some patients with acute pulmonary embolism (PE) will suffer adverse clinical outcomes despite being low risk by clinical decision rules. Emergency physician decisionmaking processes regarding which low-risk patients require hospitalization are unclear. Higher heart rate (HR) or embolic burden may increase short-term mortality risk, and we hypothesized that these variables would be associated with an increased likelihood of hospitalization for patients designated as low risk by the PE Severity Index., Methods: This was a retrospective cohort study of 461 adult emergency department (ED) patients with a PE Severity Index score of fewer than 86 points. Primary exposures were the highest observed ED HR, most proximal embolus location (proximal vs distal), and embolism laterality (bilateral vs unilateral PE). The primary outcome was hospitalization., Results: Of 461 patients meeting inclusion criteria, most (57.5%) were hospitalized, 2 patients (0.4%) died within 30 days, and 142 (30.8%) patients were at elevated risk by other criteria (Hestia criteria or biochemical/radiographic right ventricular dysfunction). Variablesassociated with an increased likelihood of admission were highest observed ED HR of ≥110 beats/minute (vs HR <90 beats/min) (adjusted odds ratio [aOR] 3.11; 95% confidence interval [CI] 1.07 to 9.57), highest ED HR 90 to 109 (aOR 2.03; 95% CI 1.18-3.50) and bilateral PE (aOR 1.92; 95% CI 1.13 to 3.27). Proximal embolus location was not associated with the likelihood of hospitalization (aOR 1.19; 95% CI 0.71 to 2.00)., Conclusions: Most patients were hospitalized, often with recognizable high-risk characteristics not accounted for by the PE Severity Index. Highest ED HR of ≥90 beats/min and bilateral PE were associated with a physician's decision for hospitalization., (Copyright © 2023 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
18. Temporal partitioning and the potential for avoidance behaviour within South African carnivore communities.
- Author
-
Smith K, Venter JA, Peel M, Keith M, and Somers MJ
- Abstract
Carnivora occupy many ecological niches fundamental to ecosystem functioning. Within this diverse order, carnivore species compete to establish dominance, ensure survival and maintain fitness. Subordinate carnivores must, therefore, adapt their behaviour to coexist with dominant species. One such strategy is the partitioning of temporal activity patterns. We aim to determine interspecific avoidance patterns among sympatric carnivores by examining coexistence along a temporal axis. We compared the temporal activity patterns of 13 carnivore species using multi-seasonal camera trapping data from four protected areas across South Africa: Associated Private Nature Reserves, Madikwe Game Reserve, Mountain Zebra National Park and Tswalu Kalahari Reserve. Interspecific coefficients of overlap in diel and core activity periods were calculated over the study period and during the wet and dry seasons. Furthermore, interspecific spatiotemporal behaviour was examined using time-to-event analyses. Our results showed that complete avoidance of diel activity patterns was rare among South African carnivore species. Most species were predominantly nocturnal and, therefore, diel activity overlap was high, whereas core activity overlap was significantly lower ( p < .001). Diel activity overlap was significantly lower during the dry than wet seasons ( p = .045). Lastly, evidence of spatiotemporal aggregation revolved around scavenging species. We show the importance of seasonality in the temporal avoidance behaviours of South African carnivores while highlighting the need for fine-scaled behavioural analyses. Overall, we show that the daily activity patterns of most subordinate South African carnivore species are not influenced by top-down forces in the form of competitional suppression and risk exerted by dominant species. If avoidance is required, it is more likely to manifest as fine-scaled avoidance of core activity periods. We suggest that the focus on core activity periods might be a more suitable tool for interspecific temporal partitioning research., Competing Interests: There are no conflicts of interest to declare., (© 2023 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)
- Published
- 2023
- Full Text
- View/download PDF
19. Evaluating Kidney Function Decline in Children with Chronic Kidney Disease Using a Multi-Institutional Electronic Health Record Database.
- Author
-
Gluck CA, Forrest CB, Davies AG, Maltenfort M, Mcdonald JR, Mitsnefes M, Dharnidharka VR, Dixon BP, Flynn JT, Somers MJ, Smoyer WE, Neu A, Hovinga CA, Skversky AL, Eissing T, Kaiser A, Breitenstein S, Furth SL, and Denburg MR
- Subjects
- Humans, Male, Child, Female, Electronic Health Records, Retrospective Studies, Disease Progression, Proteinuria etiology, Risk Factors, Glomerular Filtration Rate, Kidney, Renal Insufficiency, Chronic diagnosis, Renal Insufficiency, Chronic epidemiology, Renal Insufficiency, Chronic therapy, Hypertension epidemiology, Hypertension complications
- Abstract
Background: The objectives of this study were to use electronic health record data from a US national multicenter pediatric network to identify a large cohort of children with CKD, evaluate CKD progression, and examine clinical risk factors for kidney function decline., Methods: This retrospective cohort study identified children seen between January 1, 2009, to February 28, 2022. Data were from six pediatric health systems in PEDSnet. We identified children aged 18 months to 18 years who met criteria for CKD: two eGFR values <90 and ≥15 ml/min per 1.73 m2 separated by ≥90 days without an intervening value ≥90. CKD progression was defined as a composite outcome: eGFR <15 ml/min per 1.73 m2, ≥50% eGFR decline, long-term dialysis, or kidney transplant. Subcohorts were defined based on CKD etiology: glomerular, nonglomerular, or malignancy. We assessed the association of hypertension (≥2 visits with hypertension diagnosis code) and proteinuria (≥1 urinalysis with ≥1+ protein) within 2 years of cohort entrance on the composite outcome., Results: Among 7,148,875 children, we identified 11,240 (15.7 per 10,000) with CKD (median age 11 years, 50% female). The median follow-up was 5.1 (interquartile range 2.8-8.3) years, the median initial eGFR was 75.3 (interquartile range 61-83) ml/min per 1.73 m2, 37% had proteinuria, and 35% had hypertension. The following were associated with CKD progression: lower eGFR category (adjusted hazard ratio [aHR] 1.44 [95% confidence interval (95% CI), 1.23 to 1.69], aHR 2.38 [95% CI, 2.02 to 2.79], aHR 5.75 [95% CI, 5.05 to 6.55] for eGFR 45-59 ml/min per 1.73 m2, 30-44 ml/min per 1.73 m2, 15-29 ml/min per 1.73 m2 at cohort entrance, respectively, when compared with eGFR 60-89 ml/min per 1.73 m2), glomerular disease (aHR 2.01 [95% CI, 1.78 to 2.28]), malignancy (aHR 1.79 [95% CI, 1.52 to 2.11]), proteinuria (aHR 2.23 [95% CI, 1.89 to 2.62]), hypertension (aHR 1.49 [95% CI, 1.22 to 1.82]), proteinuria and hypertension together (aHR 3.98 [95% CI, 3.40 to 4.68]), count of complex chronic comorbidities (aHR 1.07 [95% CI, 1.05 to 1.10] per additional comorbid body system), male sex (aHR 1.16 [95% CI, 1.05 to 1.28]), and younger age at cohort entrance (aHR 0.95 [95% CI, 0.94 to 0.96] per year older)., Conclusions: In large-scale real-world data for children with CKD, disease etiology, albuminuria, hypertension, age, male sex, lower eGFR, and greater medical complexity at start of follow-up were associated with more rapid decline in kidney function., (Copyright © 2023 by the American Society of Nephrology.)
- Published
- 2023
- Full Text
- View/download PDF
20. Survival of neonates born with kidney failure during the initial hospitalization.
- Author
-
Claes DJ, Richardson T, Harer MW, Keswani M, Neu A, Mahon ACR, Somers MJ, Traum AZ, and Warady BA
- Subjects
- Infant, Newborn, Humans, Male, Child, Female, Renal Dialysis, Hospitalization, Length of Stay, Retrospective Studies, Peritoneal Dialysis adverse effects, Renal Insufficiency etiology
- Abstract
Background: Survival to hospital discharge in neonates born with kidney failure has not been previously described., Methods: This was a retrospective, observational analysis of the Pediatric Health Information System (PHIS) database from 2005 to 2019. Primary outcome was survival at discharge; secondary outcomes were hospital and ICU length of stay (LOS). Univariate analysis was performed to describe the population by birth weight (BW) and characterize survival; multivariable generalized liner mixed modeling assuming a binomial distribution and logit link was performed to identify mortality risk factors., Results: Of 213 neonates born with kidney failure (median BW 2714 g; GA 35 weeks; 68% male), 4 (1.9%) did not receive dialysis or peritoneal dialysis (PD) catheter placement, 152 (72.9%) received PD only, 49 (23.4%) received PD plus extracorporeal dialysis (ECD), and 8 (3.4%) were treated with an undocumented dialysis modality. Median age at dialysis initiation was 7 days; median hospital LOS and ICU LOS were 84 and 69 days, respectively. One-hundred and sixty-two patients (76%) survived to discharge. Non-survivors (n = 51) were more likely to have received ECD and mechanical ventilation, and had a longer duration of mechanical ventilation. Every day of mechanical ventilation increased the mortality odds by 2% (n = 189; adjusted OR 1.02; 1.01, 1.03); in addition, the odds of mortality were 2 times higher in those who received ECD vs. only PD (adjusted OR 2.25; 1.04, 4.86)., Conclusions: Survival to initial hospital discharge occurs in the majority of neonates born with kidney failure. Predictors of increased mortality included longer duration of mechanical ventilation, as well as the requirement for ECD. A higher resolution version of the Graphical abstract is available as Supplementary information., (© 2022. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)
- Published
- 2023
- Full Text
- View/download PDF
21. Giving superabsorbent polymers a second life as pressure-sensitive adhesives.
- Author
-
Chazovachii PT, Somers MJ, Robo MT, Collias DI, James MI, Marsh ENG, Zimmerman PM, Alfaro JF, and McNeil AJ
- Abstract
An estimated 6.3 billion metric tons of post-consumer polymer waste has been produced, with the majority (79%) in landfills or the environment. Recycling methods that utilize these waste polymers could attenuate their environmental impact. For many polymers, recycling via mechanical processes is not feasible and these materials are destined for landfills or incineration. One salient example is the superabsorbent material used in diapers and feminine hygiene products, which contain crosslinked sodium polyacrylates. Here we report an open-loop recycling method for these materials that involves (i) decrosslinking via hydrolysis, (ii) an optional chain-shortening via sonication, and (iii) functionalizing via Fischer esterification. The resulting materials exhibit low-to-medium storage and loss moduli, and as such, are applicable as general-purpose adhesives. A life cycle assessment demonstrates that the adhesives synthesized via this approach outcompete the same materials derived from petroleum feedstocks on nearly every metric, including carbon dioxide emissions and cumulative energy demand., (© 2021. The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
22. Patterns of coping with work-related stress: A person-centred analysis with text data.
- Author
-
Somers MJ and Casal J
- Subjects
- Humans, Interpersonal Relations, Models, Psychological, Adaptation, Psychological, Occupational Stress psychology
- Abstract
This purpose of this study was to apply the person-centred model to better understand how employees cope with work-related stress. It builds on earlier person-centred studies of coping and work-related stress by using advanced analytics and text data, and establishes the person-centred model as a viable complement to variable-centred coping research. Five profile coping groups, spanning individually-focused and socially-focused coping strategies were identified. Individually-focused profile groups included: avoidance coping based on escapism, active coping associated with physical activity, and passive coping emphasizing relaxation techniques. Socially-focused coping groups include confiding in friends and family, and engaging in social leisure activities. Implications of these findings were discussed as was the value of latent class cluster analysis with text input in person-centred coping research., (© 2020 John Wiley & Sons Ltd.)
- Published
- 2021
- Full Text
- View/download PDF
23. Species distribution modelling of Bryde's whales, humpback whales, southern right whales, and sperm whales in the southern African region to inform their conservation in expanding economies.
- Author
-
Purdon J, Shabangu FW, Yemane D, Pienaar M, Somers MJ, and Findlay K
- Abstract
In southern African waters, information about species distribution and habitat preferences of many cetacean species is limited, despite the recent economic growth that may affect them. We determined the relative importance of eight environmental variables (bathymetry, distance to shore, slope, chlorophyll-a, salinity, eastwards sea water velocity, northwards sea water velocity and sea surface temperature) as drivers of seasonal habitat preferences of Bryde's whales ( Balaenoptera brydei ), humpback whales ( Megaptera novaeangliae ), southern right whales ( Eubalaena australis ) and sperm whales ( Physeter macrocephalus ). Using presence only data from multiple sources, we constructed predictive species distribution models (SDMs) consisting of ensembles of seven algorithms for these species during both summer and winter. Predicted distribution for all cetaceans was high in southern Africa and, in particular, within the South African Exclusive Economic Zone (EEZ). Predictive models indicated a more pronounced seasonal variation for humpback, sperm and southern right whales than for Bryde's whales. Southern right whales occurred closer to shore during winter, humpback whales were more likely to occur along the east coast in winter and the west coast in summer, and sperm whales were more concentrated off the shelf in winter. Our study shows that ensemble models using historical, incidental and scientific data, in conjunction with modern environmental variables, can provide baseline knowledge on important environmental drivers of cetacean distribution for conservation purposes. Results of this study can further be used to help develop marine spatial plans and identify important marine mammal areas., Competing Interests: The authors declare there are no competing interests. Marc Pienaar is employed by South African Environmental Observation Network. Fannie Shabangu and Dawit Yemane are employed by Fisheries Management Branch, Department of Environment, Forestry and Fisheries., (©2020 Purdon et al.)
- Published
- 2020
- Full Text
- View/download PDF
24. Lions Panthera leo Prefer Killing Certain Cattle Bos taurus Types.
- Author
-
Weise FJ, Tomeletso M, Stein AB, Somers MJ, and Hayward MW
- Abstract
Lion predation on cattle causes severe human-wildlife conflict that results in retaliatory persecution throughout the lion's geographic range. Cattle closely resemble the body size, shape, and herding patterns of preferred lion prey species. We studied cattle depredation patterns in Botswana's Okavango Delta and tested whether lions exhibited specific preferences based on cattle demographic characteristics (sex and age), as well as morphological traits (body mass, horn length, and pelage patterns). We also tested whether human disturbance of kills influenced lion energy intake and whether depredation circumstances influenced loss levels. Lions predominantly killed cattle at night (87.1%) and exhibited no preference for either sex. Overall, bulls and calves were most preferred, whereas heifers were significantly avoided, as were cattle with uniform colour patterns. Cattle with mottled pelage patterns were most preferred, especially among free-roaming herds. Preferences were context-specific, with lions preferring inexperienced calves during enclosure attacks (including multiple cases of surplus killing) and free-roaming bulls and oxen. About 13% of adult cattle had no horns, and these were preferentially targeted by lions, while cattle with short horns were killed in accordance with their availability and long horned cattle were highly avoided. The contemporary morphology of Tswana cattle that resulted from unnatural selective pressures during domestication does not offer effective antipredatory protection. Human disturbance of feeding soon after kills occurred reduced cattle carcass consumption by >40% (or about 30 kg per carcass per lion). Lions killed significantly more cattle in nonfortified enclosures than in the veldt, although this was influenced by surplus killing. Our results suggest that cattle predation by lions is driven by availability and cavalier husbandry practices, coupled with morphological features associated with facilitating easy husbandry. Cattle no longer exhibit the key features that enabled their ancestors to coexist with large predators and are now reliant upon humans to perform critical antipredator activities. Hence, the responsibility for mitigating human-wildlife conflict involving lions and cattle lies with people in either breeding traits that minimise predation or adequately protecting their cattle.
- Published
- 2020
- Full Text
- View/download PDF
25. Deconstructing compassionate conservation.
- Author
-
Hayward MW, Callen A, Allen BL, Ballard G, Broekhuis F, Bugir C, Clarke RH, Clulow J, Clulow S, Daltry JC, Davies-Mostert HT, Fleming PJS, Griffin AS, Howell LG, Kerley GIH, Klop-Toker K, Legge S, Major T, Meyer N, Montgomery RA, Moseby K, Parker DM, Périquet S, Read J, Scanlon RJ, Seeto R, Shuttleworth C, Somers MJ, Tamessar CT, Tuft K, Upton R, Valenzuela-Molina M, Wayne A, Witt RR, and Wüster W
- Subjects
- Animal Welfare, Animals, Empathy, Humans, Biodiversity, Conservation of Natural Resources
- Abstract
Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public., (© 2019 Society for Conservation Biology.)
- Published
- 2019
- Full Text
- View/download PDF
26. Grazing by large savanna herbivores indirectly alters ant diversity and promotes resource monopolisation.
- Author
-
Purdon J, Parr CL, and Somers MJ
- Abstract
In savannas, grazing is an important disturbance that modifies the grass layer structure and composition. Habitat structural complexity influences species diversity and assemblage functioning. By using a combination of natural sites and manipulated experiments, we explored how habitat structure (grazing lawns and adjacent bunch grass) affects ant diversity and foraging behaviour, specifically the efficiency of resource acquisition, resource monopolisation and ant body size. We found that in the natural sites there was no difference in the amount of time ants took to locate resources, but in the manipulated experiments, ants were faster at locating resources and were more abundant in the simple treatments than in the more complex treatments. Ant body size was only affected by the manipulated experiments, with smaller ants found in the more complex treatments. In both the grazing lawn and bunch grass habitats there were differences in assemblage patterns of ants discovering resources and those dominating them. Seasonality, which was predicted to affect the speed at which ants discovered resources and the intensity of resource monopolisation, also played a role. We show that ants in winter monopolised more baits and discovered resources at a slower rate, but only at certain times within the experiment. Grazing in conjunction with season thus had a significant effect on ant diversity and foraging behaviour, with dominant ants promoted where habitat complexity was simplified when temperatures were low. Our results indicate that structural complexity plays a major role in determining ant assemblage structure and function in African savannas., Competing Interests: The authors declare there are no competing interests.
- Published
- 2019
- Full Text
- View/download PDF
27. Germinant Synergy Facilitates Clostridium difficile Spore Germination under Physiological Conditions.
- Author
-
Kochan TJ, Shoshiev MS, Hastie JL, Somers MJ, Plotnick YM, Gutierrez-Munoz DF, Foss ED, Schubert AM, Smith AD, Zimmerman SK, Carlson PE Jr, and Hanna PC
- Subjects
- Amino Acids metabolism, Animals, Bacterial Proteins metabolism, Calcium Signaling, Hydrogen-Ion Concentration, Intestine, Small metabolism, Mice, Mice, Inbred C57BL, Bile Acids and Salts metabolism, Calcium metabolism, Clostridioides difficile physiology, Intestine, Small microbiology, Spores, Bacterial physiology
- Abstract
Clostridium difficile is a Gram-positive obligate anaerobe that forms spores in order to survive for long periods in the unfavorable environment outside a host. C. difficile is the leading cause of nosocomial infectious diarrhea worldwide. C. difficile infection (CDI) arises after a patient treated with broad-spectrum antibiotics ingests infectious spores. The first step in C. difficile pathogenesis is the metabolic reactivation of dormant spores within the gastrointestinal (GI) tract through a process known as germination. In this work, we aim to elucidate the specific conditions and the location within the GI tract that facilitate this process. Our data suggest that C. difficile germination occurs through a two-step biochemical process that is regulated by pH and bile salts, amino acids, and calcium present within the GI tract. Maximal germination occurs at a pH ranging from 6.5 to 8.5 in the terminal small intestine prior to bile salt and calcium reabsorption by the host. Germination can be initiated by lower concentrations of germinants when spores are incubated with a combination of bile salts, calcium, and amino acids, and this synergy is dependent on the availability of calcium. The synergy described here allows germination to proceed in the presence of inhibitory bile salts and at physiological concentrations of germinants, effectively decreasing the concentrations of nutrients required to initiate an essential step of pathogenesis. IMPORTANCE Clostridium difficile is an anaerobic spore-forming human pathogen that is the leading cause of nosocomial infectious diarrhea worldwide. Germination of infectious spores is the first step in the development of a C. difficile infection (CDI) after ingestion and passage through the stomach. This study investigates the specific conditions that facilitate C. difficile spore germination, including the following: location within the gastrointestinal (GI) tract, pH, temperature, and germinant concentration. The germinants that have been identified in culture include combinations of bile salts and amino acids or bile salts and calcium, but in vitro , these function at concentrations that far exceed normal physiological ranges normally found in the mammalian GI tract. In this work, we describe and quantify a previously unreported synergy observed when bile salts, calcium, and amino acids are added together. These germinant cocktails improve germination efficiency by decreasing the required concentrations of germinants to physiologically relevant levels. Combinations of multiple germinant types are also able to overcome the effects of inhibitory bile salts. In addition, we propose that the acidic conditions within the GI tract regulate C. difficile spore germination and could provide a biological explanation for why patients taking proton pump inhibitors are associated with increased risk of developing a CDI.
- Published
- 2018
- Full Text
- View/download PDF
28. Updates to Clostridium difficile Spore Germination.
- Author
-
Kochan TJ, Foley MH, Shoshiev MS, Somers MJ, Carlson PE, and Hanna PC
- Subjects
- Bacillus anthracis physiology, Bacterial Proteins metabolism, Clostridioides difficile pathogenicity, Clostridium Infections drug therapy, Clostridium perfringens physiology, Humans, Membrane Proteins genetics, Membrane Proteins metabolism, Clostridioides difficile physiology, Spores, Bacterial growth & development
- Abstract
Germination of Clostridium difficile spores is a crucial early requirement for colonization of the gastrointestinal tract. Likewise, C. difficile cannot cause disease pathologies unless its spores germinate into metabolically active, toxin-producing cells. Recent advances in our understanding of C. difficile spore germination mechanisms indicate that this process is both complex and unique. This review defines unique aspects of the germination pathways of C. difficile and compares them to those of two other well-studied organisms, Bacillus anthracis and Clostridium perfringens C. difficile germination is unique, as C. difficile does not contain any orthologs of the traditional GerA-type germinant receptor complexes and is the only known sporeformer to require bile salts in order to germinate. While recent advances describing C. difficile germination mechanisms have been made on several fronts, major gaps in our understanding of C. difficile germination signaling remain. This review provides an updated, in-depth summary of advances in understanding of C. difficile germination and potential avenues for the development of therapeutics, and discusses the major discrepancies between current models of germination and areas of ongoing investigation., (Copyright © 2018 American Society for Microbiology.)
- Published
- 2018
- Full Text
- View/download PDF
29. Responsiveness of the PROMIS® measures to changes in disease status among pediatric nephrotic syndrome patients: a Midwest pediatric nephrology consortium study.
- Author
-
Selewski DT, Troost JP, Cummings D, Massengill SF, Gbadegesin RA, Greenbaum LA, Shatat IF, Cai Y, Kapur G, Hebert D, Somers MJ, Trachtman H, Pais P, Seifert ME, Goebel J, Sethna CB, Mahan JD, Gross HE, Herreshoff E, Liu Y, Carlozzi NE, Reeve BB, DeWalt DA, and Gipson DS
- Subjects
- Adolescent, Anxiety psychology, Child, Depression psychology, Fatigue psychology, Female, Humans, Interpersonal Relations, Male, Pain psychology, Prospective Studies, Health Status, Nephrotic Syndrome psychology, Patient Reported Outcome Measures, Quality of Life, Self Report standards
- Abstract
Background: Nephrotic syndrome represents a condition in pediatric nephrology typified by a relapsing and remitting course, proteinuria and the presence of edema. The PROMIS measures have previously been studied and validated in cross-sectional studies of children with nephrotic syndrome. This study was designed to longitudinally validate the PROMIS measures in pediatric nephrotic syndrome., Methods: One hundred twenty seven children with nephrotic syndrome between the ages of 8 and 17 years participated in this prospective cohort study. Patients completed a baseline assessment while their nephrotic syndrome was active, a follow-up assessment at the time of their first complete proteinuria remission or study month 3 if no remission occurred, and a final assessment at study month 12. Participants completed six PROMIS measures (Mobility, Fatigue, Pain Interference, Depressive Symptoms, Anxiety, and Peer Relationships), the PedsQL version 4.0, and two global assessment of change items., Results: Disease status was classified at each assessment: nephrotic syndrome active in 100% at baseline, 33% at month 3, and 46% at month 12. The PROMIS domains of Mobility, Fatigue, Pain Interference, Depressive Symptoms, and Anxiety each showed a significant overall improvement over time (p < 0.001). When the PROMIS measures were compared to the patients' global assessment of change, the domains of Mobility, Fatigue, Pain Interference, and Anxiety consistently changed in an expected fashion. With the exception of Pain Interference, change in PROMIS domain scores did not correlate with changes in disease activity. PROMIS domain scores were moderately correlated with analogous PedsQL domain scores., Conclusion: This study demonstrates that the PROMIS Mobility, Fatigue, Pain Interference, and Anxiety domains are sensitive to self-reported changes in disease and overall health status over time in children with nephrotic syndrome. The lack of significant anchoring to clinically defined nephrotic syndrome disease active and remission status may highlight an opportunity to improve the measurement of HRQOL in children with nephrotic syndrome through the development of a nephrotic syndrome disease-specific HRQOL measure.
- Published
- 2017
- Full Text
- View/download PDF
30. Intestinal calcium and bile salts facilitate germination of Clostridium difficile spores.
- Author
-
Kochan TJ, Somers MJ, Kaiser AM, Shoshiev MS, Hagan AK, Hastie JL, Giordano NP, Smith AD, Schubert AM, Carlson PE Jr, and Hanna PC
- Subjects
- Animals, Bacterial Proteins metabolism, Calcium Signaling, Clostridioides difficile genetics, Clostridioides difficile growth & development, Clostridium Infections metabolism, Humans, Intestine, Small metabolism, Mice, Mice, Inbred C57BL, Spores, Bacterial genetics, Spores, Bacterial metabolism, Bile Acids and Salts metabolism, Calcium metabolism, Clostridioides difficile metabolism, Clostridium Infections microbiology, Intestine, Small microbiology, Spores, Bacterial growth & development
- Abstract
Clostridium difficile (C. difficile) is an anaerobic gram-positive pathogen that is the leading cause of nosocomial bacterial infection globally. C. difficile infection (CDI) typically occurs after ingestion of infectious spores by a patient that has been treated with broad-spectrum antibiotics. While CDI is a toxin-mediated disease, transmission and pathogenesis are dependent on the ability to produce viable spores. These spores must become metabolically active (germinate) in order to cause disease. C. difficile spore germination occurs when spores encounter bile salts and other co-germinants within the small intestine, however, the germination signaling cascade is unclear. Here we describe a signaling role for Ca2+ during C. difficile spore germination and provide direct evidence that intestinal Ca2+ coordinates with bile salts to stimulate germination. Endogenous Ca2+ (released from within the spore) and a putative AAA+ ATPase, encoded by Cd630_32980, are both essential for taurocholate-glycine induced germination in the absence of exogenous Ca2+. However, environmental Ca2+ replaces glycine as a co-germinant and circumvents the need for endogenous Ca2+ fluxes. Cd630_32980 is dispensable for colonization in a murine model of C. difficile infection and ex vivo germination in mouse ileal contents. Calcium-depletion of the ileal contents prevented mutant spore germination and reduced WT spore germination by 90%, indicating that Ca2+ present within the gastrointestinal tract plays a critical role in C. difficile germination, colonization, and pathogenesis. These data provide a biological mechanism that may explain why individuals with inefficient intestinal calcium absorption (e.g., vitamin D deficiency, proton pump inhibitor use) are more prone to CDI and suggest that modulating free intestinal calcium is a potential strategy to curb the incidence of CDI.
- Published
- 2017
- Full Text
- View/download PDF
31. Tracking data from nine free-roaming Cheetahs ( Acinonyx jubatus ) collared in the Thabazimbi area, Limpopo Province, South Africa.
- Author
-
Marnewick K, Page-Nicholson S, Roxburgh L, and Somers MJ
- Abstract
Background: In partnership with the University of Pretoria, the Endangered Wildlife Trust's Carnivore Conservation Programme collared six male and three female free-roaming Cheetahs ( Acinonyx jubatus ) in the Thabazimbi area in Limpopo Province, South Africa. This study was undertaken to determine the spatial ecology of free-roaming Cheetahs that occur outside of formal protected areas on private ranchland, where they frequently come into conflict with, and are sometimes killed by, private landowners. The data were collected between September 2003 and November 2008, resulting in a total of 3165 location points (65 points from VHF collars and 3100 from GPS collars) for nine individual Cheetahs., New Information: This dataset provides distribution information about this Vulnerable species occurring outside of protected areas within South Africa. The dataset has been published to the Global Biodiversity Information Facility (www.GBIF.org) and provides the largest dataset on Cheetahs thus far, and, although it is spatially limited to a relatively small region on the African continent, it is the first study of its kind within South Africa. Also of significance is that the fate of 6 of the 9 collared Cheetahs is known, all except one of which died of anthropogenic causes.
- Published
- 2017
- Full Text
- View/download PDF
32. Dialysis in Children and Adolescents: The Pediatric Nephrology Perspective.
- Author
-
Chand DH, Swartz S, Tuchman S, Valentini RP, and Somers MJ
- Subjects
- Adolescent, Child, Decision Trees, Health Services Accessibility, Humans, Nephrology Nursing, Patient Care Team, Quality of Life, Attitude of Health Personnel, Kidney Failure, Chronic therapy, Nephrology, Pediatrics
- Abstract
The care of children with end-stage renal disease (ESRD) is highly specialized and often poorly understood by nonpediatric providers and facility/institution administrators. As such, this position paper has been created to offer provider, facility, and institutional guidance regarding the components of care necessary for children receiving dialysis. Key differences between adult and pediatric dialysis units are highlighted. Responsibilities and expectations of the members of the interdisciplinary dialysis team are outlined as they pertain specifically to the care of pediatric dialysis patients. Physical and staffing requirements of the dialysis facility are reviewed, again focusing on unique needs and challenges faced by the pediatric dialysis care team. Among these, vascular access options and proper planning of ESRD care are underscored. Pediatric quality-of-life metrics differ significantly from adult quality variables, and proper tools for assessment must be used. Endorsed by the Council of the American Society of Pediatric Nephrology (ASPN), this position paper serves as a reference tool for the provision of care to pediatric patients with ESRD., (Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
33. Simplified large African carnivore density estimators from track indices.
- Author
-
Winterbach CW, Ferreira SM, Funston PJ, and Somers MJ
- Abstract
Background: The range, population size and trend of large carnivores are important parameters to assess their status globally and to plan conservation strategies. One can use linear models to assess population size and trends of large carnivores from track-based surveys on suitable substrates. The conventional approach of a linear model with intercept may not intercept at zero, but may fit the data better than linear model through the origin. We assess whether a linear regression through the origin is more appropriate than a linear regression with intercept to model large African carnivore densities and track indices., Methods: We did simple linear regression with intercept analysis and simple linear regression through the origin and used the confidence interval for ß in the linear model y = αx + ß, Standard Error of Estimate, Mean Squares Residual and Akaike Information Criteria to evaluate the models., Results: The Lion on Clay and Low Density on Sand models with intercept were not significant ( P > 0.05). The other four models with intercept and the six models thorough origin were all significant ( P < 0.05). The models using linear regression with intercept all included zero in the confidence interval for ß and the null hypothesis that ß = 0 could not be rejected. All models showed that the linear model through the origin provided a better fit than the linear model with intercept, as indicated by the Standard Error of Estimate and Mean Square Residuals. Akaike Information Criteria showed that linear models through the origin were better and that none of the linear models with intercept had substantial support., Discussion: Our results showed that linear regression through the origin is justified over the more typical linear regression with intercept for all models we tested. A general model can be used to estimate large carnivore densities from track densities across species and study areas. The formula observed track density = 3.26 × carnivore density can be used to estimate densities of large African carnivores using track counts on sandy substrates in areas where carnivore densities are 0.27 carnivores/100 km
2 or higher. To improve the current models, we need independent data to validate the models and data to test for non-linear relationship between track indices and true density at low densities., Competing Interests: CW Winterbach and HEK Winterbach are directors and sole shareholders of Tau Consultants (Pty) Ltd., a registered independent research company in Botswana. Paul Funston is an employee of Panthera, and Sam Ferreira is employed by SANParks. Michael Somers is an Academic Editor for PeerJ.- Published
- 2016
- Full Text
- View/download PDF
34. Diet of otters (Lutra lutra) in various habitat types in the Pannonian biogeographical region compared to other regions of Europe.
- Author
-
Lanszki J, Lehoczky I, Kotze A, and Somers MJ
- Abstract
Knowledge of the effect of habitat type and region on diet and feeding behaviours of a species facilitates a better understanding of factors impacting populations, which contributes to effective conservation management. Using spraint analysis and relative frequency of occurrence data from the literature, we described the dietary patterns of Eurasian otters (Lutra lutra) in 23 study sites within the Pannonian biogeographical region in Hungary. Our results indicated that diet composition varied by habitat type and is therefore context dependant. The differences among habitat types were however lower than expected. We noticed a decline in the fish consumption with a concomitant increase in trophic niche breadth and amphibian consumption in rivers, ponds (fish farms), backwaters, marshes and small watercourses. The main differences in diet were not attributed to the consumption of primary and secondary food types (fish and amphibians), but rather to differences in other, less important food types (mammals, birds). Using hierarchical cluster analysis, rivers and ponds could clearly be separated from other habitat types. We found the main fish diet of otters in most of these areas consisted of small (<100 g), eurytopic, littoral and non-native, mostly invasive species. Dietary studies from 91 sites in six European biogeographical regions showed that fish are consumed most frequently in the Atlantic and Boreal, less in the Continental and Pannonian, and least in the Alpine and Mediterranean regions. Comparative analysis indicated that the Mediterranean region (with frequent crayfish consumption) and Alpine region (frequent amphibian consumption) cluster separate from the other regions., Competing Interests: Michael Somers is an Academic Editor for PeerJ.
- Published
- 2016
- Full Text
- View/download PDF
35. The impact of disease duration on quality of life in children with nephrotic syndrome: a Midwest Pediatric Nephrology Consortium study.
- Author
-
Selewski DT, Troost JP, Massengill SF, Gbadegesin RA, Greenbaum LA, Shatat IF, Cai Y, Kapur G, Hebert D, Somers MJ, Trachtman H, Pais P, Seifert ME, Goebel J, Sethna CB, Mahan JD, Gross HE, Herreshoff E, Liu Y, Song PX, Reeve BB, DeWalt DA, and Gipson DS
- Subjects
- Adolescent, Child, Cohort Studies, Educational Measurement statistics & numerical data, Female, Humans, Longitudinal Studies, Male, Pain etiology, Pediatrics methods, Pediatrics statistics & numerical data, Proteinuria etiology, Time, United States epidemiology, Nephrotic Syndrome complications, Nephrotic Syndrome epidemiology, Nephrotic Syndrome psychology, Quality of Life, Social Skills
- Abstract
Background: The Patient Reported Outcomes Measurement Information System (PROMIS) II is a prospective study that evaluates patient reported outcomes in pediatric chronic diseases as a measure of health-related quality of life (HRQOL). We have evaluated the influence of disease duration on HRQOL and, for the first time, compared the findings of the PROMIS measures to those of the PedsQL™ 4.0 Generic Scales (PedsQL) from the PROMIS II nephrotic syndrome (NS) longitudinal cohort., Methods: This was a prospective study in which 127 children (age range 8-17 years) with active NS from 14 centers were enrolled. Children with active NS defined as the presence of nephrotic range proteinuria (>2+ urinalysis and edema or urine protein/creatinine ratio >2 g/g) were eligible. Comparisons were made between children with prevalent (N = 67) and incident (N = 60) disease at the study enrollment visit., Results: The PROMIS scores were worse in prevalent patients in the domains of peer relationship (p = 0.01) and pain interference (p < 0.01). The PedsQL showed worse scores in prevalent patients for social functioning (p < 0.01) and school functioning (p = 0.03). Multivariable analyses showed that prevalent patients had worse scores in PROMIS pain interference (p = 0.02) and PedsQL social functioning (p < 0.01)., Conclusion: The PROMIS measures detected a significant impact of disease duration on HRQOL in children, such that peer relationships were worse and pain interfered with daily life to a greater degree among those with longer disease duration. These findings were in agreement with those for similar domains in the PedsQL legacy instrument.
- Published
- 2015
- Full Text
- View/download PDF
36. Wildlife Abundance and Diversity as Indicators of Tourism Potential in Northern Botswana.
- Author
-
Winterbach CW, Whitesell C, and Somers MJ
- Subjects
- Animals, Botswana, Surveys and Questionnaires, Animals, Wild, Biodiversity, Conservation of Natural Resources statistics & numerical data, Recreation
- Abstract
Wildlife tourism can provide economic incentives for conservation. Due to the abundance of wildlife and the presence of charismatic species some areas are better suited to wildlife tourism. Our first objective was to develop criteria based on wildlife abundance and diversity to evaluate tourism potential in the Northern Conservation Zone of Botswana. Secondly we wanted to quantify and compare tourism experiences in areas with high and low tourism potential. We used aerial survey data to estimate wildlife biomass and diversity to determine tourism potential, while data from ground surveys quantified the tourist experience. Areas used for High Paying Low Volume tourism had significantly higher mean wildlife biomass and wildlife diversity than the areas avoided for this type of tourism. Only 22% of the Northern Conservation Zone has intermediate to high tourism potential. The areas with high tourism potential, as determined from the aerial survey data, provided tourists with significantly better wildlife sightings (ground surveys) than the low tourism potential areas. Even Low Paying tourism may not be economically viable in concessions that lack areas with intermediate to high tourism potential. The largest part of the Northern Conservation Zone has low tourism potential, but low tourism potential is not equal to low conservation value. Alternative conservation strategies should be developed to complement the economic incentive provided by wildlife-based tourism in Botswana.
- Published
- 2015
- Full Text
- View/download PDF
37. Relative availability of natural prey versus livestock predicts landscape suitability for cheetahs Acinonyx jubatus in Botswana.
- Author
-
Winterbach HE, Winterbach CW, Boast LK, Klein R, and Somers MJ
- Abstract
Prey availability and human-carnivore conflict are strong determinants that govern the spatial distribution and abundance of large carnivore species and determine the suitability of areas for their conservation. For wide-ranging large carnivores such as cheetahs (Acinonyx jubatus), additional conservation areas beyond protected area boundaries are crucial to effectively conserve them both inside and outside protected areas. Although cheetahs prefer preying on wild prey, they also cause conflict with people by predating on especially small livestock. We investigated whether the distribution of cheetahs' preferred prey and small livestock biomass could be used to explore the potential suitability of agricultural areas in Botswana for the long-term persistence of its cheetah population. We found it gave a good point of departure for identifying priority areas for land management, the threat to connectivity between cheetah populations, and areas where the reduction and mitigation of human-cheetah conflict is critical. Our analysis showed the existence of a wide prey base for cheetahs across large parts of Botswana's agricultural areas, which provide additional large areas with high conservation potential. Twenty percent of wild prey biomass appears to be the critical point to distinguish between high and low probable levels of human-cheetah conflict. We identified focal areas in the agricultural zones where restoring wild prey numbers in concurrence with effective human-cheetah conflict mitigation efforts are the most immediate conservation strategies needed to maintain Botswana's still large and contiguous cheetah population.
- Published
- 2015
- Full Text
- View/download PDF
38. A single-gene cause in 29.5% of cases of steroid-resistant nephrotic syndrome.
- Author
-
Sadowski CE, Lovric S, Ashraf S, Pabst WL, Gee HY, Kohl S, Engelmann S, Vega-Warner V, Fang H, Halbritter J, Somers MJ, Tan W, Shril S, Fessi I, Lifton RP, Bockenhauer D, El-Desoky S, Kari JA, Zenker M, Kemper MJ, Mueller D, Fathy HM, Soliman NA, and Hildebrandt F
- Subjects
- Adolescent, Adult, Age of Onset, Child, Child, Preschool, Cohort Studies, Female, Genes, Wilms Tumor, Genetic Association Studies, Genotype, Heterozygote, Humans, Incidence, Infant, Male, Middle Aged, Mutation, Nephrotic Syndrome epidemiology, Nephrotic Syndrome genetics, Nephrotic Syndrome physiopathology, Pedigree, Phenotype, Real-Time Polymerase Chain Reaction, Retrospective Studies, Risk Assessment, Young Adult, Genetic Predisposition to Disease epidemiology, Intracellular Signaling Peptides and Proteins genetics, Membrane Proteins genetics, Nephrotic Syndrome congenital
- Abstract
Steroid-resistant nephrotic syndrome (SRNS) is the second most frequent cause of ESRD in the first two decades of life. Effective treatment is lacking. First insights into disease mechanisms came from identification of single-gene causes of SRNS. However, the frequency of single-gene causation and its age distribution in large cohorts are unknown. We performed exon sequencing of NPHS2 and WT1 for 1783 unrelated, international families with SRNS. We then examined all patients by microfluidic multiplex PCR and next-generation sequencing for all 27 genes known to cause SRNS if mutated. We detected a single-gene cause in 29.5% (526 of 1783) of families with SRNS that manifested before 25 years of age. The fraction of families in whom a single-gene cause was identified inversely correlated with age of onset. Within clinically relevant age groups, the fraction of families with detection of the single-gene cause was as follows: onset in the first 3 months of life (69.4%), between 4 and 12 months old (49.7%), between 1 and 6 years old (25.3%), between 7 and 12 years old (17.8%), and between 13 and 18 years old (10.8%). For PLCE1, specific mutations correlated with age of onset. Notably, 1% of individuals carried mutations in genes that function within the coenzyme Q10 biosynthesis pathway, suggesting that SRNS may be treatable in these individuals. Our study results should facilitate molecular genetic diagnostics of SRNS, etiologic classification for therapeutic studies, generation of genotype-phenotype correlations, and the identification of individuals in whom a targeted treatment for SRNS may be available., (Copyright © 2015 by the American Society of Nephrology.)
- Published
- 2015
- Full Text
- View/download PDF
39. Functional Responses of Retaliatory Killing versus Recreational Sport Hunting of Leopards in South Africa.
- Author
-
Swanepoel LH, Somers MJ, and Dalerum F
- Subjects
- Animals, Conservation of Natural Resources, Female, Humans, Male, Population Density, Recreation, South Africa, Sports, Panthera physiology
- Abstract
Predation strategies in response to altering prey abundances can dramatically influence the demographic effects of predation. Despite this, predation strategies of humans are rarely incorporated into quantitative assessments of the demographic impacts of humans killing carnivores. This scarcity largely seems to be caused by a lack of data. In this study, we contrasted predation strategies exhibited by people involved in retaliatory killing and recreational sport hunting of leopards (Panthera pardus) in the Waterberg District Municipality, South Africa. We predicted a specialist predation strategy exemplified by a type II functional response for retaliatory killing, and a generalist strategy exemplified by a type III functional response for recreational sport hunting. We could not distinguish between a type I, a type II, or a type III functional response for retaliatory killing, but the most parsimonious model for recreational sport hunting corresponded to a type I functional response. Kill rates were consistently higher for retaliatory killing than for recreational sport hunting. Our results indicate that retaliatory killing of leopards may have severe demographic consequences for leopard populations, whereas the demographic consequences of recreational sport hunting likely are less dramatic.
- Published
- 2015
- Full Text
- View/download PDF
40. Safety considerations of mammalian target of rapamycin inhibitors in tuberous sclerosis complex and renal transplantation.
- Author
-
Somers MJ and Paul E
- Subjects
- Humans, Immunosuppressive Agents therapeutic use, Protein Kinase Inhibitors therapeutic use, Sirolimus therapeutic use, Immunosuppressive Agents adverse effects, Kidney Transplantation, Protein Kinase Inhibitors adverse effects, Sirolimus adverse effects, Sirolimus analogs & derivatives, TOR Serine-Threonine Kinases antagonists & inhibitors, Tuberous Sclerosis drug therapy
- Abstract
Rapamycin-related mTOR inhibitors (rapalogs) possess immunosuppressive and antiproliferative properties. Their mechanism of action makes them attractive therapies for several disease states but also potentiates adverse effects associated with these drugs. The oral mTOR inhibitor everolimus was recently approved for the treatment of tuberous sclerosis complex (TSC)-associated renal angiomyolipoma. As clinical use of rapalogs for the treatment of TSC increases, nephrologists and urologists who treat both children and adults with renal masses, as well as internists and geneticists with an interest in renal disease, should be aware of their safety profiles. This review presents the clinical experience of rapamycin-related mTOR inhibitors in patients with TSC and summarizes their toxicity profiles in renal transplant and TSC populations. Increased usage of rapalogs in a variety of patient populations demands vigilant monitoring of their safety profiles and rigorous differentiation between disease-specific and drug-specific toxicities., (© 2014, The American College of Clinical Pharmacology.)
- Published
- 2015
- Full Text
- View/download PDF
41. Arteriovenous access monitoring with ultrasound dilution in a pediatric hemodialysis unit.
- Author
-
Ashoor IF, Hughson EA, and Somers MJ
- Subjects
- Adolescent, Algorithms, Child, Child, Preschool, Cohort Studies, Constriction, Pathologic diagnosis, Constriction, Pathologic pathology, Female, Hemofiltration instrumentation, Humans, Male, Monitoring, Physiologic instrumentation, Renal Dialysis, Renal Insufficiency, Chronic diagnostic imaging, Renal Insufficiency, Chronic physiopathology, Sensitivity and Specificity, Thrombosis diagnostic imaging, Thrombosis physiopathology, Ultrasonic Waves, Ultrasonography, Young Adult, Constriction, Pathologic diagnostic imaging, Hemofiltration methods, Monitoring, Physiologic methods, Renal Insufficiency, Chronic therapy, Thrombosis prevention & control
- Abstract
Background: Permanent arteriovenous (AV) access is the preferred access for dialysis delivery in children and adolescents requiring chronic hemodialysis (HD). Ultrasound dilution (UD) monitoring of AV access flow is widely used in adult HD units for the early detection of stenosis but experience in pediatrics is limited., Methods: We monitored all maintenance HD patients with AV access using a noninvasive screening algorithm based on UD access flow. We assessed the effectiveness of this algorithm by comparing it to fistulagrams and its impact on AV access-related morbidity., Results: AV access thrombosis rates fell from 13.5 per 100 patient-months on HD during the baseline period to 3.5 per 100 patient-months on HD during the screening period (p < 0.04). The mean blood flow rate by UD measurement was lower in AV accesses that went on to thrombose compared to those without thrombosis (1,203 ml/min/1.73 m(2) vs. 1,683 ml/min/1.73 m(2), p < 0.001). When compared to fistulagrams, the screening algorithm was 94% sensitive and 77% specific in detecting hemodynamically significant stenosis, with positive and negative predictive values of 83 and 91% respectively., Conclusions: A noninvasive UD screening algorithm of AV access flow is very sensitive in detecting hemodynamically significant stenosis and can decrease AV access thrombosis rates., (© 2015 S. Karger AG, Basel.)
- Published
- 2015
- Full Text
- View/download PDF
42. Multidisciplinary consensus on the classification of prenatal and postnatal urinary tract dilation (UTD classification system).
- Author
-
Nguyen HT, Benson CB, Bromley B, Campbell JB, Chow J, Coleman B, Cooper C, Crino J, Darge K, Herndon CD, Odibo AO, Somers MJ, and Stein DR
- Subjects
- Dilatation, Pathologic classification, Female, Humans, Infant, Newborn, Pregnancy, Consensus, Fetal Diseases classification, Urinary Tract abnormalities, Urologic Diseases classification
- Abstract
Objective: Urinary tract (UT) dilation is sonographically identified in 1-2% of fetuses and reflects a spectrum of possible uropathies. There is significant variability in the clinical management of individuals with prenatal UT dilation that stems from a paucity of evidence-based information correlating the severity of prenatal UT dilation to postnatal urological pathologies. The lack of correlation between prenatal and postnatal US findings and final urologic diagnosis has been problematic, in large measure because of a lack of consensus and uniformity in defining and classifying UT dilation. Consequently, there is a need for a unified classification system with an accepted standard terminology for the diagnosis and management of prenatal and postnatal UT dilation., Methods: A consensus meeting was convened on March 14-15, 2014, in Linthicum, Maryland, USA to propose: 1) a unified description of UT dilation that could be applied both prenatally and postnatally; and 2) a standardized scheme for the perinatal evaluation of these patients based on sonographic criteria (i.e. the classification system). The participating societies included American College of Radiology, the American Institute of Ultrasound in Medicine, the American Society of Pediatric Nephrology, the Society for Fetal Urology, the Society for Maternal-Fetal Medicine, the Society for Pediatric Urology, the Society for Pediatric Radiology and the Society of Radiologists in Ultrasounds., Results: The recommendations proposed in this consensus statement are based on a detailed analysis of the current literature and expert opinion representing common clinical practice. The proposed UTD Classification System (and hence the severity of the UT dilation) is based on six categories in US findings: 1) anterior-posterior renal pelvic diameter (APRPD); 2) calyceal dilation; 3) renal parenchymal thickness; 4) renal parenchymal appearance; 5) bladder abnormalities; and 6) ureteral abnormalities. The classification system is stratified based on gestational age and whether the UT dilation is detected prenatally or postnatally. The panel also proposed a follow-up scheme based on the UTD classification., Conclusion: The proposed grading classification system will require extensive evaluation to assess its utility in predicting clinical outcomes. Currently, the grading system is correlated with the risk of postnatal uropathies. Future research will help to further refine the classification system to one that correlates with other clinical outcomes such as the need for surgical intervention or renal function., (Copyright © 2014. Published by Elsevier Ltd.)
- Published
- 2014
- Full Text
- View/download PDF
43. Diagnosis and management of glycogen storage disease type I: a practice guideline of the American College of Medical Genetics and Genomics.
- Author
-
Kishnani PS, Austin SL, Abdenur JE, Arn P, Bali DS, Boney A, Chung WK, Dagli AI, Dale D, Koeberl D, Somers MJ, Wechsler SB, Weinstein DA, Wolfsdorf JI, and Watson MS
- Subjects
- Antiporters genetics, Diagnosis, Differential, Glucose-6-Phosphatase genetics, Glycogen Storage Disease Type I pathology, Humans, Monosaccharide Transport Proteins genetics, Glycogen Storage Disease Type I diagnosis, Glycogen Storage Disease Type I therapy
- Abstract
Purpose: Glycogen storage disease type I (GSD I) is a rare disease of variable clinical severity that primarily affects the liver and kidney. It is caused by deficient activity of the glucose 6-phosphatase enzyme (GSD Ia) or a deficiency in the microsomal transport proteins for glucose 6-phosphate (GSD Ib), resulting in excessive accumulation of glycogen and fat in the liver, kidney, and intestinal mucosa. Patients with GSD I have a wide spectrum of clinical manifestations, including hepatomegaly, hypoglycemia, lactic acidemia, hyperlipidemia, hyperuricemia, and growth retardation. Individuals with GSD type Ia typically have symptoms related to hypoglycemia in infancy when the interval between feedings is extended to 3–4 hours. Other manifestations of the disease vary in age of onset, rate of disease progression, and severity. In addition, patients with type Ib have neutropenia, impaired neutrophil function, and inflammatory bowel disease. This guideline for the management of GSD I was developed as an educational resource for health-care providers to facilitate prompt, accurate diagnosis and appropriate management of patients., Methods: A national group of experts in various aspects of GSD I met to review the evidence base from the scientific literature and provided their expert opinions. Consensus was developed in each area of diagnosis, treatment, and management., Results: This management guideline specifically addresses evaluation and diagnosis across multiple organ systems (hepatic, kidney, gastrointestinal/nutrition, hematologic, cardiovascular, reproductive) involved in GSD I. Conditions to consider in the differential diagnosis stemming from presenting features and diagnostic algorithms are discussed. Aspects of diagnostic evaluation and nutritional and medical management, including care coordination, genetic counseling, hepatic and renal transplantation, and prenatal diagnosis, are also addressed., Conclusion: A guideline that facilitates accurate diagnosis and optimal management of patients with GSD I was developed. This guideline helps health-care providers recognize patients with all forms of GSD I, expedite diagnosis, and minimize adverse sequelae from delayed diagnosis and inappropriate management. It also helps to identify gaps in scientific knowledge that exist today and suggests future studies.
- Published
- 2014
- Full Text
- View/download PDF
44. Landscape suitability in Botswana for the conservation of its six large African carnivores.
- Author
-
Winterbach HE, Winterbach CW, and Somers MJ
- Subjects
- Animals, Biomass, Botswana, Feasibility Studies, Livestock, Body Size, Carnivora anatomy & histology, Conservation of Natural Resources statistics & numerical data, Ecosystem
- Abstract
Wide-ranging large carnivores often range beyond the boundaries of protected areas into human-dominated areas. Mapping out potentially suitable habitats on a country-wide scale and identifying areas with potentially high levels of threats to large carnivore survival is necessary to develop national conservation action plans. We used a novel approach to map and identify these areas in Botswana for its large carnivore guild consisting of lion (Panthera leo), leopard (Panthera pardus), spotted hyaena (Crocuta crocuta), brown hyaena (Hyaena brunnea), cheetah (Acinonyx jubatus) and African wild dog (Lycaon pictus). The habitat suitability for large carnivores depends primarily on prey availability, interspecific competition, and conflict with humans. Prey availability is most likely the strongest natural determinant. We used the distribution of biomass of typical wild ungulate species occurring in Botswana which is preyed upon by the six large carnivores to evaluate the potential suitability of the different management zones in the country to sustain large carnivore populations. In areas where a high biomass of large prey species occurred, we assumed interspecific competition between dominant and subordinated competitors to be high. This reduced the suitability of these areas for conservation of subordinate competitors, and vice versa. We used the percentage of prey biomass of the total prey and livestock biomass to identify areas with potentially high levels of conflict in agricultural areas. High to medium biomass of large prey was mostly confined to conservation zones, while small prey biomass was more evenly spread across large parts of the country. This necessitates different conservation strategies for carnivores with a preference for large prey, and those that can persist in the agricultural areas. To ensure connectivity between populations inside Botswana and also with its neighbours, a number of critical areas for priority management actions exist in the agricultural zones.
- Published
- 2014
- Full Text
- View/download PDF
45. Trophic scaling and occupancy analysis reveals a lion population limited by top-down anthropogenic pressure in the Limpopo National Park, Mozambique.
- Author
-
Everatt KT, Andresen L, and Somers MJ
- Subjects
- Animals, Buffaloes, Geography, Humans, Models, Theoretical, Mozambique, Population Dynamics, Ecosystem, Human Activities, Lions growth & development
- Abstract
The African lion (Panthera Leo) has suffered drastic population and range declines over the last few decades and is listed by the IUCN as vulnerable to extinction. Conservation management requires reliable population estimates, however these data are lacking for many of the continent's remaining populations. It is possible to estimate lion abundance using a trophic scaling approach. However, such inferences assume that a predator population is subject only to bottom-up regulation, and are thus likely to produce biased estimates in systems experiencing top-down anthropogenic pressures. Here we provide baseline data on the status of lions in a developing National Park in Mozambique that is impacted by humans and livestock. We compare a direct density estimate with an estimate derived from trophic scaling. We then use replicated detection/non-detection surveys to estimate the proportion of area occupied by lions, and hierarchical ranking of covariates to provide inferences on the relative contribution of prey resources and anthropogenic factors influencing lion occurrence. The direct density estimate was less than 1/3 of the estimate derived from prey resources (0.99 lions/100 km² vs. 3.05 lions/100 km²). The proportion of area occupied by lions was Ψ = 0.439 (SE = 0.121), or approximately 44% of a 2,400 km2 sample of potential habitat. Although lions were strongly predicted by a greater probability of encountering prey resources, the greatest contributing factor to lion occurrence was a strong negative association with settlements. Finally, our empirical abundance estimate is approximately 1/3 of a published abundance estimate derived from opinion surveys. Altogether, our results describe a lion population held below resource-based carrying capacity by anthropogenic factors and highlight the limitations of trophic scaling and opinion surveys for estimating predator populations exposed to anthropogenic pressures. Our study provides the first empirical quantification of a population that future change can be measured against.
- Published
- 2014
- Full Text
- View/download PDF
46. Space use of African wild dogs in relation to other large carnivores.
- Author
-
Darnell AM, Graf JA, Somers MJ, Slotow R, and Szykman Gunther M
- Subjects
- Animals, Dogs, Ecosystem, Geography, Models, Theoretical, Population Dynamics, South Africa, Carnivora, Predatory Behavior
- Abstract
Interaction among species through competition is a principle process structuring ecological communities, affecting behavior, distribution, and ultimately the population dynamics of species. High competition among large African carnivores, associated with extensive diet overlap, manifests in interactions between subordinate African wild dogs (Lycaon pictus) and dominant lions (Panthera leo) and spotted hyenas (Crocuta crocuta). Using locations of large carnivores in Hluhluwe-iMfolozi Park, South Africa, we found different responses from wild dogs to their two main competitors. Wild dogs avoided lions, particularly during denning, through a combination of spatial and temporal avoidance. However, wild dogs did not exhibit spatial or temporal avoidance of spotted hyenas, likely because wild dog pack sizes were large enough to adequately defend their kills. Understanding that larger carnivores affect the movements and space use of other carnivores is important for managing current small and fragmented carnivore populations, especially as reintroductions and translocations are essential tools used for the survival of endangered species, as with African wild dogs.
- Published
- 2014
- Full Text
- View/download PDF
47. Space use as an indicator of enclosure appropriateness in African wild dogs (Lycaon pictus).
- Author
-
Hunter SC, Gusset M, Miller LJ, and Somers MJ
- Subjects
- Animal Welfare, Animals, Environment Design, Female, Male, Models, Statistical, Animals, Zoo psychology, Behavior, Animal, Canidae psychology, Housing, Animal
- Abstract
A clear understanding of space use is required to more fully understand biological requirements of nonhuman animals in zoos, aid the design of exhibits, and maximize the animals' welfare. This study used electivity indexes to assess space use of two packs of African wild dogs (Lycaon pictus) and the appropriateness of two naturalistic, outdoor enclosures at the San Diego Zoo and Bronx Zoo. The results identified enclosure features that were both underutilized and overutilized. They suggest that replacing underutilized areas with features similar to areas that were overutilized may provide more preferred opportunities for the animals. Assessing space use of animals in human care may serve as an indicator of enclosure appropriateness and could have welfare implications. By looking at the possible reasons for area preferences, animal managers can get an idea of where improvements could be made. Designing future exhibits accordingly thus can provide possible welfare benefits for the animals concerned.
- Published
- 2014
- Full Text
- View/download PDF
48. KDOQI US commentary on the 2012 KDIGO clinical practice guideline for glomerulonephritis.
- Author
-
Beck L, Bomback AS, Choi MJ, Holzman LB, Langford C, Mariani LH, Somers MJ, Trachtman H, and Waldman M
- Subjects
- Glomerulonephritis epidemiology, Humans, Randomized Controlled Trials as Topic methods, Randomized Controlled Trials as Topic standards, United States, Glomerulonephritis diagnosis, Glomerulonephritis therapy, Practice Guidelines as Topic standards, Research Report standards
- Abstract
Glomerulonephritis (GN) is an important cause of morbidity and mortality in patients of all ages throughout the world. Because these disorders are relatively rare, it is difficult to perform randomized clinical trials to define optimal treatment for many of the specific glomerulopathies. In the absence of high-grade evidence to guide the care of glomerular diseases, in June 2012, KDIGO (Kidney Disease: Improving Global Outcomes) published an international clinical guideline for GN. The Work Group report represents an important review of the literature in this area and offers valid and useful guidelines for the most common situations that arise in the management of patients with glomerular disease. This commentary, developed by a panel of clinical experts convened by the National Kidney Foundation, attempts to put the GN guideline into the context of the US health care system. Overall, we support the vast majority of the recommendations and highlight select areas in which epidemiological factors and medical practice patterns in this country justify modifications and adjustments in order to achieve favorable outcomes. There remain large gaps in our knowledge of the best approaches to treat glomerular disease and we strongly endorse an expanded clinical research effort to improve the health and long-term outcomes of children and adults with GN., (Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
49. Continuous renal replacement therapy for children ≤10 kg: a report from the prospective pediatric continuous renal replacement therapy registry.
- Author
-
Askenazi DJ, Goldstein SL, Koralkar R, Fortenberry J, Baum M, Hackbarth R, Blowey D, Bunchman TE, Brophy PD, Symons J, Chua A, Flores F, and Somers MJ
- Subjects
- Child, Preschool, Cohort Studies, Female, Humans, Infant, Infant, Newborn, Kidney Diseases mortality, Kidney Function Tests, Male, Prospective Studies, Registries, Kidney Diseases therapy, Renal Replacement Therapy
- Abstract
Objective: To report circuit characteristics and survival analysis in children weighing ≤10 kg enrolled in the Prospective Pediatric Continuous Renal Replacement Therapy (ppCRRT) Registry., Study Design: We conducted prospective cohort analysis of the ppCRRT Registry to: (1) evaluate survival differences in children ≤10 kg compared with other children; (2) determine demographic and clinical differences between surviving and non-surviving children ≤10 kg; and (3) describe continuous renal replacement therapy (CRRT) circuit characteristics differences in children ≤5 kg versus 5-10 kg., Results: The ppCRRT enrolled 84 children ≤10 kg between January 2001 and August 2005 from 13 US tertiary centers. Children ≤10 kg had lower survival rates than children >10 kg (36/84 [43%] versus 166/260 [64%]; P < .001). In children ≤10 kg, survivors were more likely to have fewer days in intensive care unit prior to CRRT, lower Pediatric Risk of Mortality 2 scores at intensive care unit admission and lower mean airway pressure (P(aw)), higher urine output, and lower percent fluid overload (FO) at CRRT initiation. Adjusted regression analysis revealed that Pediatric Risk of Mortality 2 scores, FO, and decreased urine output were associated with mortality. Compared with circuits from children 5-10 kg at CRRT initiation, circuits from children ≤5 kg more commonly used blood priming for initiation, heparin anticoagulation, and higher blood flows/effluent flows for body weight., Conclusion: Mortality is more common in children who are ≤10 kg at the time of CRRT initiation. Like other CRRT populations, urine output and FO at CRRT initiation are independently associated with mortality. CRRT prescription differs in small children., (Copyright © 2013 Mosby, Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
50. Apheresis therapy in children: an overview of key technical aspects and a review of experience in pediatric renal disease.
- Author
-
Hunt EA, Jain NG, and Somers MJ
- Subjects
- Adolescent, Anticoagulants adverse effects, Anticoagulants pharmacology, Anxiety prevention & control, Blood Component Removal adverse effects, Blood Component Removal instrumentation, Blood Component Removal psychology, Blood Component Removal statistics & numerical data, Blood Volume, Catheterization, Central Venous, Child, Citric Acid adverse effects, Citric Acid pharmacology, Erythrocytes, Graft Rejection therapy, Humans, Hypocalcemia drug therapy, Hypocalcemia etiology, Hypocalcemia prevention & control, Immunosorbent Techniques, Kidney Transplantation, Plasma Exchange methods, Solutions, Vascular Access Devices, Blood Component Removal methods, Kidney Diseases therapy, Nephrology methods, Pediatrics methods
- Abstract
Although there is less experience with its use in children than adults, apheresis can be a life-saving treatment modality in certain pediatric diseases. With attention to specific technical aspects of the treatment, especially circuit volume, apheresis can be safely performed in children of any age or size. Even in pediatric diseases where it is recognized as an important part of therapy, apheresis is unfortunately still underutilized in North America and there needs to be increased awareness of its role and its availability within the pediatric community. Apheresis has been used particularly in children with certain renal diseases, notably ANCA-associated nephritis, anti-GBM disease, and atypical HUS. In addition, it can improve outcomes in transplantation of children with FSGS and can be part of a pre-transplant strategy for children who are highly sensitized and at high risk for graft failure., (Copyright © 2013 Wiley Periodicals, Inc.)
- Published
- 2013
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.