171 results on '"Taylor NA"'
Search Results
2. Long-term outcomes of iris-sutured subluxated intraocular lenses
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Taylor Nayman, Daniel Milad, and Mikael Sebag
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iris-sutured lens ,iol exchange ,pars plana vitrectomy ,Ophthalmology ,RE1-994 - Abstract
Purpose: This study evaluated the long-term outcomes of managing posterior chamber intra-ocular lens (IOL) (PCIOL) subluxation through pars plana vitrectomy (PPV) with IOL iris suturing. Settings and Design: Retrospective chart review. Methods: Patients who underwent PPV with iris-sutured IOL (IS-IOL) for IOL subluxation between January 2008 and April 2021 at a tertiary center with a minimum of 6 months of follow-up were included. The patients were divided into two groups: those who had prior PPV and those who had not undergone the procedure. Results: A total of 54 patients underwent iris suturing of a subluxated IOL. Among them, 36 (66%) had previously undergone PPV, while 18 patients (33%) had not. The etiology of PCIOL subluxation was uncertain in 20 (37.0%), prior PPV in 17 (32%), and following complicated cataract surgery in 11 (20%) cases. The mean time between original IOL insertion and IS-IOL was 6.1 ± 7.0 years. The mean follow-up duration was 46.8 ± 39.7 months. The mean post-operative best corrected visual acuity (BCVA) was logMAR 0.43 ± 0.52 at final follow-up, a significant improvement from pre-operative BCVA. Vision was significantly better in the group with no prior PPV (logMAR 0.54 ± 0.59 vs. 0.21 ± 0.23 at final follow-up, P = 0.026). At final follow-up, 34 (63%) eyes had BCVA of 20/40 or better. The most common complication was cystoid macular edema, attributed to the IS-IOL in 13 (21.4%) eyes, 11 (68.6%) of which resolved or improved. Conclusions: The management of posterior chamber IOL subluxations with PPV and iris suturing of the subluxated IOL is a safe technique that provides excellent long-term visual outcomes.
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- 2024
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3. Permanent ocular remodeling in the setting of chronic hypotony after trabeculectomy: A case report
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Nathaniel Cameron, Taylor Nayman, Sanjay V. Patel, and Gavin W. Roddy
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Hypotony ,Intra-ocular lens ,Trabeculectomy ,Glaucoma ,Ophthalmology ,RE1-994 - Abstract
Purpose: Trabeculectomy surgery is a commonly performed procedure for treatment of glaucoma. While the goal is to lower intraocular pressure, over-filtration may cause hypotony with ocular structural changes and vision loss. Observations: A 53-year-old woman with primary open-angle glaucoma was referred to our service for further evaluation. The patient previously underwent trabeculectomy 9 years prior and was found to have a cataract and hypotony maculopathy in the right eye. Treatment options included cataract surgery alone, bleb revision alone, or combined cataract extraction and bleb revision. Biometry revealed corneal astigmatism in the right eye, and significant disparity in axial length between the two eyes. Since the axial length and corneal astigmatic changes were presumed to be at least partially reversible, measurements from the non-operative left eye influenced the lens selection for the hypotonous right eye. The patient underwent combined phacoemulsification and bleb revision. While IOP increased and hypotony was partly reversed, there was hyperopic and astigmatic refractive surprise after surgery.The patient subsequently underwent intraocular lens exchange using biometric values of the previously hypotonous eye and met the target post-operative refractive goal. Conclusions and importance: This case demonstrates changes to the axial length and ocular structure following longstanding hypotony maculopathy may be permanent, even after restoration of normotensive intraocular pressure.
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- 2024
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4. Host interneurons mediate plasticity reactivated by embryonic inhibitory cell transplantation in mouse visual cortex
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XiaoTing Zheng, Kirstie J. Salinas, Dario X. Figueroa Velez, Taylor Nakayama, Xiaoxiao Lin, Dhruba Banerjee, Xiangmin Xu, and Sunil P. Gandhi
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Science - Abstract
Transplantation of embryonic interneurons can restore juvenile plasticity to the adult host visual cortex. Here, the authors show that transplanted embryonic interneurons reactivate cortical plasticity via Neuregulin/ErbB4 signaling in host parvalbumin interneurons.
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- 2021
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5. Idiopathic intracranial hypertension in a pediatric transgender patient
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Taylor Nayman, Mélanie Hébert, and Luis H. Ospina
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Idiopathic intracranial hypertension ,Pediatric ,Transgender ,Hormone therapy ,Androgens ,Papilledema ,Ophthalmology ,RE1-994 - Abstract
Purpose: Androgens given for gender affirmation have been implicated in the pathophysiology of idiopathic intracranial hypertension (IIH) in transgender patients. 10 cases of transgender adults with IIH have been published but this association has not been described in younger patients. Herein we describe the first case of IIH in an adolescent transgender patient. Observations: A 17-year-old non-obese female-to-male transgender patient on subcutaneous testosterone since age 13 presented with a two-month history of transient visual obscuration and frontal headaches. Ophthalmological examination revealed Frisen grade 2 papilledema with preserved visual function. Lumbar puncture confirmed elevated opening pressure. Papilledema resolved with oral acetazolamide and reduction of testosterone therapy. Conclusions and Importance: The use of cross-sex hormone therapy (CSH) for gender affirmation may increase the risk of IIH. Awareness of this association is important as the number of younger transgender patients seeking CSH is increasing significantly.
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- 2021
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6. Engaging Learners via Live Online Learning
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Taylor Nash and Megan S. Cantrell
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Online Learning ,Extension ,Virtual Classroom ,Synchronous Learning ,Agriculture (General) ,S1-972 ,Plant culture ,SB1-1110 ,Biology (General) ,QH301-705.5 - Abstract
The explosion of virtual training and education has created opportunities for interactions far beyond what is available in a face-to-face environment. However, easier access to individuals comes with unforeseen challenges in creating an environment that fosters genuine engagement. This new publication includes engagement strategies for the Extension environment as well as the virtual classroom of traditional education. Written by Taylor Nash and Megan Cantrell; 3 pp. https://edis.ifas.ufl.edu/wc395
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- 2021
7. Sandflies and leishmaniasis
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Croft, AM, primary, Taylor, NA, additional, and Rodenhurst, KE, additional
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- 2006
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8. Icebreakers for Adults
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Megan Stein and Taylor Nash
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building rapport ,team culture ,small-group development ,Agriculture (General) ,S1-972 ,Plant culture ,SB1-1110 ,Biology (General) ,QH301-705.5 - Abstract
Building rapport is key when creating a team culture. As groups change over time, it is imperative to continually reintroduce and reacclimate new team members to long-standing teammates. Leaders of groups that undergo constant change, like those whose jobs involve volunteers, may find it challenging to find innovative ways to bring people together. Icebreakers are quick, low- or no-cost activities that allow individuals to get to know the people around them and serve as a means to build trust and openness in a low-stakes environment. This new 3-page publication of the UF/IFAS Department of Agricultural Education and Communication outlines strategies to use when building a team culture and gives examples of simple activities to build cultures within teams or groups. Written by Megan Stein and Taylor Nash.
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- 2020
9. Sorting of PC2 to the regulated secretory pathway in AtT20 cells
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Taylor, NA, primary, Jan, G, additional, Scougall, KT, additional, Docherty, K, additional, and Shennan, KI, additional
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- 1998
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10. To cool, but not too cool: that is the question-immersion cooling for hyperthermia.
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Taylor NA, Caldwell JN, Van Den Heuvel AM, and Patterson MJ
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INTRODUCTION:: Patient cooling time can impact upon the prognosis of heat illness. Although ice-cold-water immersion will rapidly extract heat, access to ice or cold water may be limited in hot climates. Indeed, some have concerns regarding the sudden cold-water immersion of hyperthermic individuals, whereas others believe that cutaneous vasoconstriction may reduce convective heat transfer from the core. It was hypothesized that warmer immersion temperatures, which induce less powerful vasoconstriction, may still facilitate rapid cooling in hyperthermic individuals. METHODS:: Eight males participated in three trials and were heated to an esophageal temperature of 39.5 degrees C by exercising in the heat (36 degrees C, 50% relative humidity) while wearing a water-perfusion garment (40 degrees C). Subjects were cooled using each of the following methods: air (20-22 degrees C), cold-water immersion (14 degrees C), and temperate-water immersion (26 degrees C). RESULTS:: The time to reach an esophageal temperature of 37.5 degrees C averaged 22.81 min (air), 2.16 min (cold), and 2.91 min (temperate). Whereas each of the between-trial comparisons was statistically significant (P < 0.05), cooling in temperate water took only marginally longer than that in cold water, and one cannot imagine that the 45-s cooling time difference would have any meaningful physiological or clinical implications. CONCLUSION:: It is assumed that this rapid heat loss was due to a less powerful peripheral vasoconstrictor response, with central heat being more rapidly transported to the skin surface for dissipation. Although the core-to-water thermal gradient was much smaller with temperate-water cooling, greater skin and deeper tissue blood flows would support a superior convective heat delivery. Thus, a sustained physiological mechanism (blood flow) appears to have countered a less powerful thermal gradient, resulting in clinically insignificant differences in heat extraction between the cold and temperate cooling trials. [ABSTRACT FROM AUTHOR]
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- 2008
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11. Scientific Basis of Phototherapy
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Griffith, &NA;, primary and Taylor, &NA;, additional
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- 1928
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12. Isolated receptor binding domains of HTLV-1 and HTLV-2 envelopes bind Glut-1 on activated CD4+ and CD8+ T cells
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Montel-Hagen Amélie, Mongellaz Cedric, Lavanya Madakasira, Swainson Louise, Kinet Sandrina, Craveiro Marco, Manel Nicolas, Battini Jean-Luc, Sitbon Marc, and Taylor Naomi
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Immunologic diseases. Allergy ,RC581-607 - Abstract
Abstract Background We previously identified the glucose transporter Glut-1, a member of the multimembrane-spanning facilitative nutrient transporter family, as a receptor for both HTLV-1 and HTLV-2. However, a recent report concluded that Glut-1 cannot serve as a receptor for HTLV-1 on CD4 T cells: This was based mainly on their inability to detect Glut-1 on this lymphocyte subset using the commercial antibody mAb1418. It was therefore of significant interest to thoroughly assess Glut-1 expression on CD4 and CD8 T cells, and its association with HTLV-1 and -2 envelope binding. Results As previously reported, ectopic expression of Glut-1 but not Glut-3 resulted in significantly augmented binding of tagged proteins harboring the receptor binding domains of either HTLV-1 or HTLV-2 envelope glycoproteins (H1RBD or H2RBD). Using antibodies raised against the carboxy-terminal peptide of Glut-1, we found that Glut-1 expression was significantly increased in both CD4 and CD8 cells following TCR stimulation. Corresponding increases in the binding of H1RBD as well as H2RBD, not detected on quiescent T cells, were observed following TCR engagement. Furthermore, increased Glut-1 expression was accompanied by a massive augmentation in glucose uptake in TCR-stimulated CD4 and CD8 lymphocytes. Finally, we determined that the apparent contradictory results obtained by Takenouchi et al were due to their monitoring of Glut-1 with a mAb that does not bind cells expressing endogenous Glut-1, including human erythrocytes that harbor 300,000 copies per cell. Conclusion Transfection of Glut-1 directly correlates with the capacities of HTLV-1 and HTLV-2 envelope-derived ligands to bind cells. Moreover, Glut-1 is induced by TCR engagement, resulting in massive increases in glucose uptake and binding of HTLV-1 and -2 envelopes to both CD4 and CD8 T lymphocytes. Therefore, Glut-1 is a primary binding receptor for HTLV-1 and HTLV-2 envelopes on activated CD4 as well as CD8 lymphocytes.
- Published
- 2007
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13. The interaction of body armor, low-intensity exercise, and hot-humid conditions on physiological strain and cognitive function.
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Caldwell JN, Engelen L, van der Henst C, Patterson MJ, Taylor NA, Caldwell, Joanne N, Engelen, Lian, van der Henst, Charles, Patterson, Mark J, and Taylor, Nigel A S
- Abstract
Objective: This project was aimed at evaluating the impact of combat armor on physiological and cognitive functions during low-intensity exercise in hot-humid conditions (36 degrees C and 60% relative humidity).Methods: Nine males participated in three trials (2.5 hours), walking at two speeds and wearing different protective equipment: control (combat uniform and cloth hat); torso armor with uniform and cloth hat; and full armor (uniform, torso armor, and helmet).Results: As time progressed, core temperatures increased and deviated significantly among trials, rising at 0.37 degrees C h(-1) (control), 0.41 degrees C h(-1) (torso armor), and 0.51 degrees C h(-1) (full armor). Heart rates also progressively diverged, and subjects lost significantly more sweat during the two armored trials. However, cognitive-function tests revealed neither significant main effects nor time by treatment interactions.Conclusion: The combat armor and helmet significantly increased thermal and cardiovascular strain, but these were unlikely to lead to either exertional heat illness or impaired cognitive function during uneventful urban, military patrols in hot-humid conditions. [ABSTRACT FROM AUTHOR]- Published
- 2011
14. Local Control of Pyoderma Gangrenosum Using Human Amniotic Membrane and Transcriptome Analysis.
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Maier MA, Dennis JR, Fontenot CJ, Taylor NA, Almukhtar R, Lau FHP, and Smith AA
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Pyoderma gangrenosum (PG) is a rare, chronic, ulcerative disease characterized by non-healing wounds that worsen with debridement, a phenomenon called pathergy. No consensus regarding pathogenesis, diagnosis, or treatment exists for PG. A previous pilot study using dehydrated human amniotic/chorionic membrane (dHACM), following excisional debridement, augmented PG wound healing and allowed for subsequent wound closure through split-thickness skin grafting (STSG). In this clinical trial (NCT05120726), four patients with an established PG diagnosis were enrolled to undergo treatment with dHACM and characterize the pre- and post-treatment transcriptome profiles. RNA sequencing was used to isolate the total RNA from specimens. Genes of particular interest were quantified through real-time quantitative reverse transcription polymerase chain reaction. We observed varied changes to the local expression of inflammatory response, positive regulators of cellular proliferation, and extracellular matrix disassembly cytokines. All PG wounds produced granulation tissue following treatment and were closed using split-thickness skin grafts., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: The corresponding author serves as a paid consultant for Aroa Biosurgery and is on the advisory board for Prytime Medical. Otherwise, the authors have no relevant conflicts of interest to disclose.
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- 2024
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15. Impact of cystic fibrosis multidisciplinary virtual clinics on patient experience, time commitments and costs.
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Bell JM, Dwyer TJ, Cunich M, Dentice RL, Hutchings O, Jo HE, Lau EM, Lee WY, Nolan SA, Munoz P, Raffan F, Shah K, Shaw M, Taylor NA, Visser SK, Yozghatlian VA, Wong KKH, and Sivam S
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- Humans, Male, Female, Adult, Prospective Studies, Middle Aged, Videoconferencing, Patient Reported Outcome Measures, Ambulatory Care economics, Patient Satisfaction, Patient Care Team, Cystic Fibrosis therapy, Cystic Fibrosis economics, Telemedicine economics
- Abstract
Background and Aims: The experience of outpatient care may differ for select patient groups. This prospective study evaluates the adult patient experience of multidisciplinary outpatient cystic fibrosis (CF) care with videoconferencing through telehealth compared with face-to-face care the year prior., Methods: People with CF without a lung transplant were recruited. Patient-reported outcomes were obtained at commencement and 12 months into the study, reflecting both their face-to-face and telehealth through videoconferencing experience, respectively. Three patient cohorts were analysed: (i) participants with a regional residence, (ii) participants with a nonregional including metropolitan residence and (iii) participants with colonised multiresistant microbiota., Results: Seventy-four patients were enrolled in the study (mean age, 37 ± 11 years; 50% male; mean forced expiratory volume in the first second of expiration, 60% [standard deviation, 23]) between February 2020 and May 2021. No differences between models were observed in the participants' rating of the health care team, general and mental health rating, and their confidence in handling treatment plans at home. No between-group differences in the Cystic Fibrosis Questionnaire - Revised (CFQ-R) were observed. Travel duration and the cost of attending a clinic was significantly reduced, particularly for the regional group (4 h, AU$108 per clinic; P < 0.05). A total of 93% respondents preferred to continue with a hybrid approach., Conclusion: In this pilot study, participants' experience of care and quality of life were no different with face-to-face and virtual care between the groups. Time and cost-savings, particularly for patients living in regional areas, were observed. Most participants preferred to continue with a hybrid model for outpatient care., (© 2023 Royal Australasian College of Physicians.)
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- 2024
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16. Does Time to Pelvic Fixation Influence Outcomes in Trauma Patients?
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Taylor NA, Smith AA, Marr A, Stuke L, Greiffenstein P, Schoen J, Brown T, Chapman B, and Hunt JP
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- Fracture Fixation methods, Humans, Injury Severity Score, Length of Stay, Prospective Studies, Retrospective Studies, Fractures, Bone etiology, Fractures, Bone surgery, Pelvic Bones injuries, Pelvic Bones surgery
- Abstract
Background: Pelvic fractures cause significant morbidity in the trauma population. Many factors influence time to fracture fixation. No previous study has determined the optimal time window for pelvic fixation., Methods: A retrospective review of trauma patients with pelvic fractures from 2016 to 2020 was performed. Patients were stratified into EARLY and LATE groups, by time to fixation within 3 days or greater than 3 days whether from admission or from completion of a life-saving procedure. Unpaired Student's t -test and Fisher's exact test were performed with multiple linear regression for variables with P < .2 on univariate analysis., Results: 287 patients were identified with a median fixation time of 3 days. There was no significant difference in demographics, incidence of preceding life-saving procedure, angioembolization, or mechanism of injury in the 2 groups ( P > .05). Length of stay in the EARLY group was significantly reduced at 11.9 +/- .7 days compared to 18.0 +/-1.2 days in the LATE group ( P < .001). There was no significant difference in rates of ventilator-associated pneumonia, deep vein thrombosis, pulmonary embolism (PE), acute kidney injury (AKI), pressure ulcer, or acute respiratory distress syndrome (ARDS) ( P > .05). There were significantly more SSIs (surgical site infections) in the LATE group. After multiple linear regression adjusting for covariates of age and ISS, the difference in hospital LOS was 5.5 days (95% CI -8.0 to -3.1, P < .001)., Discussion: Fixation of traumatic pelvic fractures within 3 days reduced LOS. Prospective multi-center studies will help identify additional factors to decrease time to surgery and improve patient outcomes.
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- 2022
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17. Quality of home spirometry performance amongst adults with cystic fibrosis.
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Bell JM, Sivam S, Dentice RL, Dwyer TJ, Jo HE, Lau EM, Munoz PA, Nolan SA, Taylor NA, Visser SK, Yozghatlian VA, and Wong KK
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- Adult, Female, Home Care Services, Humans, Male, Middle Aged, Prospective Studies, Cystic Fibrosis therapy, Quality of Health Care, Spirometry methods, Telemedicine methods
- Abstract
Spirometry is usually performed under the supervision of a trained respiratory scientist to ensure acceptability and repeatability of results. To evaluate the quality of spirometry performance by adult cystic fibrosis (CF) patients with and without observation by a trained respiratory scientist, an observational, single centre study was conducted between February to December 2020. 74 adults were recruited and instructed to perform spirometry without supervision within 24 h of their remote CF clinic consultation. Spirometry was repeated at their consultation, supervised by a respiratory scientist using video conferencing. The majority of patients achieved grade A (excellent) or B (very good) spirometry quality with (95%) and without supervision (93%) independent of lung function severity. Similarly, forced expiratory volume in 1 second demonstrated no significant differences with paired spirometry performed within a 24 hour period. For a large proportion of adult CF patients, unsupervised portable spirometry produces acceptable and repeatable results., Competing Interests: Declaration of Competing Interest There are no conflicts of interests for all authors in regards to this study., (Copyright © 2021. Published by Elsevier B.V.)
- Published
- 2022
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18. CT and PET-CT Surveillance in Stages 3A to 3D Melanoma Results in More False-Positive than True-Positive Findings and Should Not be Routinely Recommended.
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Taylor NA and Brodland DG
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- Fluorodeoxyglucose F18, Humans, Melanoma diagnostic imaging, Positron Emission Tomography Computed Tomography
- Published
- 2021
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19. Use of Herbal Medications for Treatment of Osteoarthritis and Rheumatoid Arthritis.
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Lindler BN, Long KE, Taylor NA, and Lei W
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Arthritis is a chronic condition that affects nearly a quarter of the United States population. Osteoarthritis (OA) and rheumatoid arthritis (RA) are two major forms of arthritis associated with severe joint pain and reduced quality of life. Various pharmacological interventions may be utilized for arthritis treatment when non-pharmacological therapy is insufficient. However, pharmacological therapy can be associated with serious side effects and high costs. Therefore, alternative therapies have been under investigation. Herbal medications have shown the potential for safe and effective management of arthritis. For this review, we attempt to summarize the mechanisms, safety, and efficacy of herbal treatments for OA and RA. After searching electronic databases, we identified nine herbs among 23 clinical trials used for the treatment of OA or RA patients. Improvement of OA and RA symptoms, pain, and inflammation was demonstrated. The herbs exhibited strong anti-inflammatory and anti-oxidant activities, contributing to a reduction in inflammation and tissue damage. Several herbs elucidated new mechanisms for OA and RA treatment as well. Though these herbs have shown promise for OA and RA treatment, more studies and clinical trials are required for determining safety and efficacy, bioactivity, and optimal bioavailability.
- Published
- 2020
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20. Four Cultural Narratives for Managing Social-ecological Complexity in Public Natural Resource Management.
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Kirsop-Taylor NA, Hejnowicz AP, and Scott K
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- Food, Food Supply, Water, Conservation of Natural Resources, Natural Resources
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Public Natural Resource Management (NRM) agencies operate in complex social-ecological domains. These complexities proliferate unpredictably therefore investigating and supporting the ability of public agencies to respond effectively is increasingly important. However, understanding how public NRM agencies innovate and restructure to negotiate the range of particular complexities they face is an under researched field. One particular conceptualisation of the social-ecological complexities facing NRM agencies that is of growing influence is the Water-Energy-Food (WEF) nexus. Yet, as a tool to frame and understand those complexities it has limitations. Specifically, it overlooks how NRMs respond institutionally to these social-ecological complexities in the context of economic and organisational challenges-thus creating a gap in the literature. Current debates in public administration can be brought to bear here. Using an organisational cultures approach, this paper reports on a case study with a national NRM agency to investigate how they are attempting to transform institutionally to respond to complexity in challenging times. The research involved 12 elite interviews with senior leaders from Natural Resources Wales, (NRW) and investigated how cultural narratives are being explicitly and implicitly constructed and mobilised to this end. The research identified four distinct and sequential cultural narratives: collaboration, communication, trust, and empowerment where each narrative supported the delivery of different dimensions of NRW's social-ecological complexity mandate. Counter to the current managerialist approaches in public administration, these results suggest that the empowerment of expert bureaucrats is important in responding effectively to complexity.
- Published
- 2020
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21. A 3D biofabricated cutaneous squamous cell carcinoma tissue model with multi-channel confocal microscopy imaging biomarkers to quantify antitumor effects of chemotherapeutics in tissue.
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Browning JR, Derr P, Derr K, Doudican N, Michael S, Lish SR, Taylor NA, Krueger JG, Ferrer M, Carucci JA, and Gareau DS
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Cutaneous squamous cell carcinoma (cSCC) causes approximately 10,000 deaths annually in the U. S. Current therapies are largely ineffective against metastatic and locally advanced cSCC. There is a need to identify novel, effective, and less toxic small molecule cSCC therapeutics. We developed a 3-dimensional bioprinted skin (3DBPS) model of cSCC tumors together with a microscopy assay to test chemotherapeutic effects in tissue. The full thickness SCC tissue model was validated using hematoxylin and eosin (H&E) and immunohistochemical histological staining, confocal microscopy, and cDNA microarray analysis. A nondestructive, 3D fluorescence confocal imaging assay with tdTomato-labeled A431 SCC and ZsGreen-labeled keratinocytes was developed to test efficacy and general toxicity of chemotherapeutics. Fluorescence-derived imaging biomarkers indicated that 50% of cancer cells were killed in the tissue after 1μM 5-Fluorouracil 48-hour treatment, compared to a baseline of 12% for untreated controls. The imaging biomarkers also showed that normal keratinocytes were less affected by treatment (11% killed) than the untreated tissue, which had no significant killing effect. Data showed that 5-Fluorouracil selectively killed cSCC cells more than keratinocytes. Our 3DBPS assay platform provides cellular-level measurement of cell viability and can be adapted to achieve nondestructive high-throughput screening (HTS) in bio-fabricated tissues., Competing Interests: CONFLICTS OF INTEREST The authors state no conflicts of interest., (Copyright: © 2020 Browning et al.)
- Published
- 2020
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22. Nevus psiloliparus: Newly described histopathological features from transverse sections.
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Roman J, Taylor NA, Oza VS, and Kim RH
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- Child, Female, Humans, Alopecia pathology, Lipomatosis pathology, Scalp Dermatoses pathology
- Abstract
Nevus psiloliparus is a rare fatty tissue nevus that is a marker for encephalocraniocutaneous lipomatosis, a neurocutaneous syndrome with ocular and central nervous system anomalies. Clinically, nevus psiloliparus is often described as a congenital alopecia and appears as an irregularly shaped, circumscribed area of alopecia on the scalp. Histopathology demonstrates a near-complete absence of mature hair follicles with preservation of arrector pili muscles and mature adipocytes within the dermis. The pathogenesis of nevus psiloliparus may be related to mosaic mutations in fibroblast growth factor receptor 1. Herein we report the histopathological features of a nevus psiloliparus in an 11-year-old girl diagnosed from transverse sections, which show "shadow" follicular units characterized by columns of loosely arranged collagen and a relative paucity of elastic fibers., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
- Published
- 2020
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23. Patterns of Diabetes Screening and Prediabetes Treatment during Office Visits in the US.
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Shealy KM, Wu J, Waites J, Taylor NA, and Blair Sarbacker G
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- Adolescent, Adult, Aged, Case-Control Studies, Cross-Sectional Studies, Diet, Healthy, Exercise, Female, Health Care Surveys, Humans, Hypoglycemic Agents therapeutic use, Male, Metformin therapeutic use, Middle Aged, Office Visits statistics & numerical data, Prediabetic State therapy, United States, Young Adult, Diabetes Mellitus, Type 2 prevention & control, Mass Screening statistics & numerical data, Prediabetic State diagnosis
- Abstract
Introduction: The American Diabetes Association recommends annual screenings for prediabetes if the patient meets the suggested requirements. The overall prevalence of prediabetes has decreased from an estimated 86 million adults in 2012 to 84.1 million adults in 2015 in the United States. Along with lifestyle modifications, the use of metformin as a treatment option or in combination has shown a decrease in weight and health care costs. This study was designed to review the prevalence of screening and treatment of prediabetes in the United States by using the National Ambulatory Medical Care Survey, as well as identify any factors associated with screenings and treatment., Methods: The National Ambulatory Medical Care Survey was used to examine a study sample of office visits between 2012 and 2015, reviewing the prevalence of screenings and lab services ordered or provided at each patient visit. Inclusion criteria consisted of the recommendations given by the American Diabetes Association including any patient ≥45 years or adult patient <45 years with a body mass index of ≥25 kg/m
2 and an additional risk factor. Patients with a previous diagnosis of diabetes were excluded from the sample., Results: A total of 105,721 office visits (2012 to 2015) were included in the analysis. The diabetes screening prevalence increased from 10% in 2012 to 13.4% in 2015. Metformin (n = 140, 76.1%) was the most common antidiabetic medication prescribed to treat prediabetes., Conclusions: The prevalence of diabetes screening during office visits remained lower than 15% between 2012 and 2015 in the United States. Physicians primarily prescribe lifestyle modifications, including a healthy diet and exercise, with metformin being used in some cases for the prevention of diabetes., Competing Interests: Conflict of interest: none declared., (© Copyright 2019 by the American Board of Family Medicine.)- Published
- 2019
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24. Treg depletion potentiates checkpoint inhibition in claudin-low breast cancer.
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Taylor NA, Vick SC, Iglesia MD, Brickey WJ, Midkiff BR, McKinnon KP, Reisdorf S, Anders CK, Carey LA, Parker JS, Perou CM, Vincent BG, and Serody JS
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- Animals, Antineoplastic Agents pharmacology, Biomarkers, Tumor metabolism, CD4-Positive T-Lymphocytes immunology, CTLA-4 Antigen metabolism, Chemokine CXCL12 metabolism, Cluster Analysis, Disease Models, Animal, Female, Gene Expression Profiling, Humans, Lymphocytes, Tumor-Infiltrating cytology, Mammary Neoplasms, Animal drug therapy, Mammary Neoplasms, Animal immunology, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Oligonucleotide Array Sequence Analysis, Programmed Cell Death 1 Receptor metabolism, Triple Negative Breast Neoplasms immunology, Tumor Microenvironment, Cell Cycle Checkpoints, Claudins metabolism, Lymphocytes, Tumor-Infiltrating immunology, T-Lymphocytes, Regulatory immunology, Triple Negative Breast Neoplasms drug therapy
- Abstract
Claudin-low breast cancer is an aggressive subtype that confers poor prognosis and is found largely within the clinical triple-negative group of breast cancer patients. Here, we have shown that intrinsic and immune cell gene signatures distinguish the claudin-low subtype clinically as well as in mouse models of other breast cancer subtypes. Despite adaptive immune cell infiltration in claudin-low tumors, treatment with immune checkpoint inhibitory antibodies against cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and programmed death receptor 1 (PD-1) were ineffective in controlling tumor growth. CD4+FoxP3+ Tregs represented a large proportion of the tumor-infiltrating lymphocytes (TILs) in claudin-low tumors, and Tregs isolated from tumor-bearing mice were able to suppress effector T cell responses. Tregs in the tumor microenvironment highly expressed PD-1 and were recruited partly through tumor generation of the chemokine CXCL12. Antitumor efficacy required stringent Treg depletion combined with checkpoint inhibition; delays in tumor growth were not observed using therapies that modestly diminished the number of Tregs in the tumor microenvironment. This study provides evidence that the recruitment of Tregs to the tumor microenvironment inhibits an effective antitumor immune response and highlights early Treg recruitment as a possible mechanism for the lack of response to immune checkpoint blockade antibodies in specific subtypes of cancer that are heavily infiltrated with adaptive immune cells.
- Published
- 2017
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25. Indirect hand and forearm vasomotion: Regional variations in cutaneous thermosensitivity during normothermia and mild hyperthermia.
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Burdon CA, Tagami K, Park J, Caldwell JN, and Taylor NA
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- Adult, Female, Heart Rate, Heating, Humans, Hyperthermia, Induced, Male, Skin Temperature, Sweating, Body Temperature Regulation, Forearm blood supply, Hand blood supply, Regional Blood Flow, Skin blood supply, Thermosensing
- Abstract
In this experiment, hand and forearm vasomotor activity was investigated during localised, but stable heating and cooling of the face, hand and thigh, under open-loop (clamped) conditions. It was hypothesised that facial stimulation would provoke the most potent vascular changes. Nine individuals participated in two normothermic trials (mean body temperature clamp: 36.6°C; water-perfused suit and climate chamber) and two mildly hyperthermic trials (37.9°C). Localised heating (+5°C) and cooling (-5°C) stimuli were applied to equal surface areas of the face, hand and thigh (perfusion patches: 15min), while contralateral forearm or hand blood flows (venous-occlusion plethysmography) were measured (separate trials). Thermal sensation and discomfort votes were recorded before and during each thermal stimulation. When hyperthermic, local heating induced more sensitive vascular responses, with the combined thermosensitivity of both limb segments averaging 0.011mL·100mL
-1 ·min-1 ·mmHg-1 ·°C-1 , and 0.005mL·100mL-1 ·min-1 ·mmHg-1 ·°C-1 during localised cooling (P<0.05). Inter-site comparisons among the stimulated sites yielded minimal evidence of variations in local thermal sensation, and no differences were observed for vascular conductance (P>0.05). Therefore, regional differences in vasomotor and sensory sensitivity appeared not to exist. When combined with previous observations of sudomotor sensitivity, it seems that, during mild heating and cooling, regional representations within the somatosensory cortex may not translate into meaningful differences in thermal sensation or the central integration of thermoafferent signals. It was concluded that inter-site variations in the cutaneous thermosensitivity of these thermolytic effectors have minimal physiological significance over the ranges investigated thus far., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
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26. Thermogenic and psychogenic recruitment of human eccrine sweat glands: Variations between glabrous and non-glabrous skin surfaces.
- Author
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Machado-Moreira CA and Taylor NA
- Subjects
- Adult, Body Temperature, Body Temperature Regulation, Heart Rate, Heating, Humans, Male, Stress, Psychological, Young Adult, Eccrine Glands physiology, Skin Physiological Phenomena, Sweating
- Abstract
Human eccrine sweat-gland recruitment and secretion rates were investigated from the glabrous (volar) and non-glabrous hand surfaces during psychogenic (mental arithmetic) and thermogenic stimuli (mild hyperthermia). It was hypothesised that these treatments would activate glands from both skin surfaces, with the non-thermal stimulus increasing secretion rates primarily by recruiting more sweat glands. Ten healthy men participated in two seated, resting trials in temperate conditions (25-26°C). Trials commenced under normothermic conditions during which the first psychogenic stress was applied. That was followed by passive heating (0.5°C mean body temperature elevation) and thermal clamping, with a second cognitive challenge then applied. Sudomotor activity was evaluated from both hands, with colourimetry used to identify activated sweat glands, skin conductance to determine the onset of precursor sweating and ventilated sweat capsules to measure rates of discharged sweating. From glandular activation and sweat rate data, sweat-gland outputs were derived. These psychogenic and thermogenic stimuli activated sweat glands from both the glabrous and non-glabrous skin surfaces, with the former dominating at the glabrous skin and the latter at the non-glabrous surface. Indeed, those stimuli individually accounted for ~90% of the site-specific maximal number of activated sweat glands observed when both stimuli were simultaneously applied. During the normothermic psychological stimulation, sweating from the glabrous surface was elevated via a 185% increase in the number of activated glands within the first 60s. The hypothetical mechanism for this response may involve the serial activation of additional eccrine sweat glands during the progressive evolution of psychogenic sweating., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
27. Intraocular pressure and cerebral oxygenation during prolonged headward acceleration.
- Author
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Eiken O, Keramidas ME, Taylor NA, and Grönkvist M
- Subjects
- Adult, Cerebrovascular Circulation, Female, Frontal Lobe blood supply, Frontal Lobe physiology, Head physiology, Humans, Male, Stress, Physiological, Unconsciousness etiology, Unconsciousness physiopathology, Acceleration adverse effects, Frontal Lobe metabolism, Gravitation, Intraocular Pressure, Oxygen Consumption, Unconsciousness metabolism
- Abstract
Purpose: Supra-tolerance head-to-foot directed gravitoinertial load (+Gz) typically induces a sequence of symptoms/signs, including loss of: peripheral vision-central vision-consciousness. The risk of unconsciousness is greater when anti-G-garment failure occurs after prolonged rather than brief exposures, presumably because, in the former condition, mental signs are not consistently preceded by impaired vision. The aims were to investigate if prolonged exposure to moderately elevated +Gz reduces intraocular pressure (IOP; i.e., improves provisions for retinal perfusion), or the cerebral anoxia reserve., Methods: Subjects were exposed to 4-min +Gz plateaux either at 2 and 3 G (n = 10), or at 4 and 5 G (n = 12). Measurements included eye-level mean arterial pressure (MAP), oxygenation of the cerebral frontal cortex, and at 2 and 3 G, IOP., Results: IOP was similar at 1 (14.1 ± 1.6 mmHg), 2 (14.0 ± 1.6 mmHg), and 3 G (14.0 ± 1.6 mmHg). During the G exposures, MAP exhibited an initial prompt drop followed by a partial recovery, end-exposure values being reduced by ≤30 mmHg. Cerebral oxygenation showed a similar initial drop, but without recovery, and was followed by either a plateau or a further slight decrement to a minimum of about -14 μM., Conclusion: Gz loading did not affect IOP. That cerebral oxygenation remained suppressed throughout these G exposures, despite a concomitant partial recovery of MAP, suggests that the increased risk of unconsciousness upon G-garment failure after prolonged +Gz exposure is due to reduced cerebral anoxia reserve., Competing Interests: The authors declare that they have no conflicts of interest.
- Published
- 2017
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28. Bioelectromagnetics Research within an Australian Context: The Australian Centre for Electromagnetic Bioeffects Research (ACEBR).
- Author
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Loughran SP, Al Hossain MS, Bentvelzen A, Elwood M, Finnie J, Horvat J, Iskra S, Ivanova EP, Manavis J, Mudiyanselage CK, Lajevardipour A, Martinac B, McIntosh R, McKenzie R, Mustapic M, Nakayama Y, Pirogova E, Rashid MH, Taylor NA, Todorova N, Wiedemann PM, Vink R, Wood A, Yarovsky I, and Croft RJ
- Abstract
Mobile phone subscriptions continue to increase across the world, with the electromagnetic fields (EMF) emitted by these devices, as well as by related technologies such as Wi-Fi and smart meters, now ubiquitous. This increase in use and consequent exposure to mobile communication (MC)-related EMF has led to concern about possible health effects that could arise from this exposure. Although much research has been conducted since the introduction of these technologies, uncertainty about the impact on health remains. The Australian Centre for Electromagnetic Bioeffects Research (ACEBR) is a National Health and Medical Research Council Centre of Research Excellence that is undertaking research addressing the most important aspects of the MC-EMF health debate, with a strong focus on mechanisms, neurodegenerative diseases, cancer, and exposure dosimetry. This research takes as its starting point the current scientific status quo, but also addresses the adequacy of the evidence for the status quo. Risk communication research complements the above, and aims to ensure that whatever is found, it is communicated effectively and appropriately. This paper provides a summary of this ACEBR research (both completed and ongoing), and discusses the rationale for conducting it in light of the prevailing science., Competing Interests: Robert McIntosh and Steve Iskra are full-time employees of Telstra Corporation. Raymond McKenzie is a full time employee of the Australian Mobile Telecommunications Association the remaining authors declare no conflict of interest.
- Published
- 2016
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29. Morphological dependency of cutaneous blood flow and sweating during compensable heat stress when heat-loss requirements are matched across participants.
- Author
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Notley SR, Park J, Tagami K, Ohnishi N, and Taylor NA
- Subjects
- Adiposity physiology, Adolescent, Adult, Body Temperature physiology, Exercise physiology, Forearm blood supply, Forearm physiology, Heat Stress Disorders physiopathology, Hot Temperature, Humans, Male, Rest physiology, Vasomotor System physiology, Young Adult, Body Temperature Regulation physiology, Regional Blood Flow physiology, Skin blood supply, Stress, Physiological physiology, Sweating physiology
- Abstract
Human heat loss is thought, in part, to be morphologically related. It was therefore hypothesized that when heat-loss requirements and body temperatures were matched, that the mass-specific surface area alone could significantly explain both cutaneous vascular and sudomotor responses during compensable exercise. These thermoeffector responses were examined in 36 men with widely varying mass-specific surface areas (range, 232.3-292.7 cm(2)/kg), but of similar age, aerobic fitness, and adiposity. Subjects completed two trials under compensable conditions (28.1°C, 36.8% relative humidity), each involving rest (20 min) and steady-state cycling (45 min) at two matched metabolic heat-production rates (light, ∼135 W/m(2); moderate, ∼200 W/m(2)). Following equivalent mean body temperature changes, forearm blood flow and vascular conductance (r = 0.63 and r = 0.65) shared significant, positive associations with the mass-specific surface area during light work (P < 0.05), explaining ∼45% of the vasomotor variation. Conversely, during light and moderate work, whole body sweat rate, as well as local sweat rate and sudomotor sensitivity at three of four measured sites, revealed moderate, negative relationships with the mass-specific surface area (correlation coefficient range -0.37 to -0.73, P < 0.05). Moreover, those relationships could uniquely account for between 10 and 53% of those sweating responses (P < 0.05). Therefore, both thermoeffector responses displayed a significant morphological dependency in the presence of equivalent thermoafferent drive. Indeed, up to half of the interindividual variation in these effector responses could now be explained through morphological differences and the first principles governing heat transfer., (Copyright © 2016 the American Physiological Society.)
- Published
- 2016
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30. Load carriage, human performance, and employment standards.
- Author
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Taylor NA, Peoples GE, and Petersen SR
- Subjects
- Body Size, Firefighters, Gait physiology, Humans, Military Personnel, Muscle Fatigue, Physical Endurance, Risk Factors, Employment standards, Occupational Health standards, Physical Fitness, Workload standards
- Abstract
The focus of this review is on the physiological considerations necessary for developing employment standards within occupations that have a heavy reliance on load carriage. Employees within military, fire fighting, law enforcement, and search and rescue occupations regularly work with heavy loads. For example, soldiers often carry loads >50 kg, whilst structural firefighters wear 20-25 kg of protective clothing and equipment, in addition to carrying external loads. It has long been known that heavy loads modify gait, mobility, metabolic rate, and efficiency, while concurrently elevating the risk of muscle fatigue and injury. In addition, load carriage often occurs within environmentally stressful conditions, with protective ensembles adding to the thermal burden of the workplace. Indeed, physiological strain relates not just to the mass and dimensions of carried objects, but to how those loads are positioned on and around the body. Yet heavy loads must be borne by men and women of varying body size, and with the expectation that operational capability will not be impinged. This presents a recruitment conundrum. How do employers identify capable and injury-resistant individuals while simultaneously avoiding discriminatory selection practices? In this communication, the relevant metabolic, cardiopulmonary, and thermoregulatory consequences of loaded work are reviewed, along with concomitant impediments to physical endurance and mobility. Also emphasised is the importance of including occupation-specific clothing, protective equipment, and loads during work-performance testing. Finally, recommendations are presented for how to address these issues when evaluating readiness for duty.
- Published
- 2016
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31. Towards best practice in physical and physiological employment standards.
- Author
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Petersen SR, Anderson GS, Tipton MJ, Docherty D, Graham TE, Sharkey BJ, and Taylor NA
- Subjects
- Humans, Meta-Analysis as Topic, Employment standards, Occupational Health standards, Physical Fitness
- Abstract
While the scope of the term physical employment standards is wide, the principal focus of this paper is on standards related to physiological evaluation of readiness for work. Common applications of such employment standards for work are in public safety and emergency response occupations (e.g., police, firefighting, military), and there is an ever-present need to maximize the scientific quality of this research. Historically, most of these occupations are male-dominated, which leads to potential sex bias during physical demands analysis and determining performance thresholds. It is often assumed that older workers advance to positions with lower physical demand. However, this is not always true, which raises concerns about the long-term maintenance of physiological readiness. Traditionally, little attention has been paid to the inevitable margin of uncertainty that exists around cut-scores. Establishing confidence intervals around the cut-score can reduce for this uncertainty. It may also be necessary to consider the effects of practise and biological variability on test scores. Most tests of readiness for work are conducted under near perfect conditions, while many emergency responses take place under far more demanding and unpredictable conditions. The potential impact of protective clothing, respiratory protection, load carriage, environmental conditions, nutrition, fatigue, sensory deprivation, and stress should also be considered when evaluating readiness for work. In this paper, we seek to establish uniformity in terminology in this field, identify key areas of concern, provide recommendations to improve both scientific and professional practice, and identify priorities for future research.
- Published
- 2016
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32. Non-thermal modulation of sudomotor function during static exercise and the impact of intensity and muscle-mass recruitment.
- Author
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Gordon CJ, Caldwell JN, and Taylor NA
- Abstract
Aim : Static muscle activation elicits intensity-dependent, non-thermal sweating that is presumably controlled by feedforward (central command) mechanisms. However, it is currently unknown how the size of the recruited muscle mass interacts with that mechanism. To investigate the possible muscle-size dependency of that non-thermal sweating, the recruitment of two muscle groups of significantly different size was investigated in individuals within whom steady-state thermal sweating had been established and clamped. Methods : Fourteen passively heated subjects (climate chamber and water-perfusion garment) performed 60-s, static handgrip and knee-extension activations at 30% and 50% of maximal voluntary force, plus a handgrip at 40% intensity (143.4 N) and a third knee extension at the same absolute force. Local sweating from four body segments (averaged to represent whole-body sudomotor activity), three deep-body and eight skin temperatures, heart rates and perceptions of physical effort were measured continuously, and analyzed over the final 30 s of exercise. Results : In the presence of thermal clamping and low-level, steady-state sweating, static muscle activation resulted in exercise-intensity dependent changes in the whole-body sudomotor response during these handgrip and knee-extension actions ( P < 0.05). However, there was no evidence of a dependency on the size of the recruited muscle mass ( P > 0.05), yet both dependencies were apparent for heart rate, and partially evident for the sensations of physical effort. Conclusion : These observations represent the first evidence that exercise-related sudomotor feedforward is not influenced by the size of the activated muscle mass, but is instead primarily dictated by the intensity of the exercise itself.
- Published
- 2016
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33. Thermal and cardiovascular strain imposed by motorcycle protective clothing under Australian summer conditions.
- Author
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de Rome L, Taylor EA, Croft RJ, Brown J, Fitzharris M, and Taylor NA
- Subjects
- Adult, Australia, Humans, Male, Middle Aged, Pilot Projects, Seasons, Fever etiology, Heart Rate, Hot Temperature adverse effects, Motorcycles, Oxygen Consumption, Protective Clothing, Skin Temperature, Sweating
- Abstract
Motorcycle protective clothing can be uncomfortably hot during summer, and this experiment was designed to evaluate the physiological significance of that burden. Twelve males participated in four, 90-min trials (cycling 30 W) across three environments (25, 30, 35 °C [all 40% relative humidity]). Clothing was modified between full and minimal injury protection. Both ensembles were tested at 25 °C, with only the more protective ensemble investigated at 30 and 35 °C. At 35 °C, auditory canal temperature rose at 0.02 °C min(-1) (SD 0.005), deviating from all other trials (p < 0.05). The thresholds for moderate (>38.5 °C) and profound hyperthermia (>40.0 °C) were predicted to occur within 105 min (SD 20.6) and 180 min (SD 33.0), respectively. Profound hyperthermia might eventuate in ~10 h at 30 °C, but should not occur at 25 °C. These outcomes demonstrate a need to enhance the heat dissipation capabilities of motorcycle clothing designed for summer use in hot climates, but without compromising impact protection. Practitioner's Summary: Motorcycle protective clothing can be uncomfortably hot during summer. This experiment was designed to evaluate the physiological significance of this burden across climatic states. In the heat, moderate (>38.5 °C) and profound hyperthermia (>40.0 °C) were predicted to occur within 105 and 180 min, respectively.
- Published
- 2016
- Full Text
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34. The effects of thoracic load carriage on maximal ambulatory work tolerance and acceptable work durations.
- Author
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Peoples GE, Lee DS, Notley SR, and Taylor NA
- Subjects
- Adult, Humans, Male, Work of Breathing, Exercise physiology, Exercise Tolerance, Respiratory Muscles physiology, Torso physiology
- Abstract
Purpose: Torso loads restrict chest-wall movement and ventilation, particularly during heavy exercise. Therefore, the differential impact of load carriage and chest-wall restriction was investigated during progressive treadmill exercise. In addition, acceptable work durations were derived across a wide range of submaximal, loaded exercise intensities., Methods: Twelve males participated in two research phases. Phase 1: Three incremental treadmill tests until exhaustion [control (clothing only), load carriage (clothing plus 22-kg vest), and clothing with chest strapping]. Phase 2: Five steady-state exercise trials (clothing plus 22-kg vest) at intensities from 30 to 80 % of peak aerobic power to determine maximal acceptable work durations., Results: Maximal work tolerance [control 17.21 min (±0.93); loaded 13.44 min (±0.68); strapped 17.00 min (±0.83)] and the mass-specific peak aerobic power [control 61.61 mL kg(-1) min(-1) (±2.28); loaded 45.42 mL kg(-1) min(-1) (±1.41); strapped 59.99 mL kg(-1) min(-1) (±1.61)] were reduced only when loaded (P < 0.05). Peak minute ventilation was retained, although loading and chest strapping reduced the breathing reserve. The lower and upper acceptable work duration derivations when working at the 30 % intensity were 133.40 min (±23.77) and 220.10 min (±48.69), but at 80 % intensity, both durations were reduced to <7 min., Conclusion: Thoracic loading significantly reduced exercise tolerance and the breathing reserve, but did not modify peak minute ventilation or the absolute peak aerobic power. Chest strapping, as used herein, exerted minimal impact. However, the projected maximal acceptable work durations were much less than derived using previously published methods.
- Published
- 2016
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35. Balancing ballistic protection against physiological strain: evidence from laboratory and field trials.
- Author
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Taylor NA, Burdon CA, van den Heuvel AM, Fogarty AL, Notley SR, Hunt AP, Billing DC, Drain JR, Silk AJ, Patterson MJ, and Peoples GE
- Subjects
- Forensic Ballistics, Humans, Male, Military Personnel, Young Adult, Protective Clothing, Stress, Physiological physiology, Wounds, Gunshot prevention & control
- Abstract
This project was based on the premise that decisions concerning the ballistic protection provided to defence personnel should derive from an evaluation of the balance between protection level and its impact on physiological function, mobility, and operational capability. Civilians and soldiers participated in laboratory- and field-based studies in which ensembles providing five levels of ballistic protection were evaluated, each with progressive increases in protection, mass (3.4-11.0 kg), and surface-area coverage (0.25-0.52 m(2)). Physiological trials were conducted on volunteers (N = 8) in a laboratory, under hot-dry conditions simulating an urban patrol: walking at 4 km·h(-1) (90 min) and 6 km·h(-1) (30 min or to fatigue). Field-based trials were used to evaluate tactical battlefield movements (mobility) of soldiers (N = 31) under tropical conditions, and across functional tests of power, speed, agility, endurance, and balance. Finally, trials were conducted at a jungle training centre, with soldiers (N = 32) patrolling under tropical conditions (averaging 5 h). In the laboratory, work tolerance was reduced as protection increased, with deep-body temperature climbing relentlessly. However, the protective ensembles could be grouped into two equally stressful categories, each providing a different level of ballistic protection. This outcome was supported during the mobility trials, with the greatest performance decrement evident during fire and movement simulations, as the ensemble mass was increased (-2.12%·kg(-1)). The jungle patrol trials similarly supported this outcome. Therefore, although ballistic protection does increase physiological strain, this research has provided a basis on which to determine how that strain can be balanced against the mission-specific level of required personal protection.
- Published
- 2016
- Full Text
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36. Interactions of mean body and local skin temperatures in the modulation of human forearm and calf blood flows: a three-dimensional description.
- Author
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Caldwell JN, Matsuda-Nakamura M, and Taylor NA
- Subjects
- Adult, Humans, Male, Forearm blood supply, Leg blood supply, Regional Blood Flow, Skin Temperature
- Abstract
Aim: The inter-relationships between mean body and local skin temperatures have previously been established for controlling hand and foot blood flows. Since glabrous skin contains many arteriovenous anastomoses, it was important to repeat those experiments on non-glabrous regions using the same sample and experimental conditions., Methods: Mild hypothermia (mean body temperature 31.4 °C), normothermia (control: 36.0 °C) and moderate hyperthermia (38.3 °C) were induced and clamped (climate chamber and water-perfusion garment) in eight males. Within each condition, five localised thermal treatments (5, 15, 25, 33, 40 °C) were applied to the left forearm and right calf. Steady-state forearm and calf blood flows were measured (venous occlusion plethysmography) for each of the resulting 15 combinations of clamped mean body and local skin temperatures., Results: Under the normothermic clamp, cutaneous blood flows averaged 4.2 mL 100 mL(-1) min(-1) (±0.28: forearm) and 5.4 mL 100 mL(-1) min(-1) (±0.27: calf). When mildly hypothermic, these segments were unresponsive to localised thermal stimuli, but tracked those changes when normothermic and moderately hyperthermic. For deep-body (oesophageal) temperature elevations, forearm blood flow increased by 5.1 mL 100 mL(-1) min(-1) °C(-1) (±0.9) relative to normothermia, while the calf was much less responsive: 3.3 mL 100 mL(-1) min(-1) °C(-1) (±1.5). Three-dimensional surfaces revealed a qualitative divergence in the control of calf blood flow, with vasoconstrictor tone apparently being released more gradually., Conclusion: These descriptions reinforce the importance of deep-tissue temperatures in controlling cutaneous perfusion, with this modulation being non-linear at the forearm and appearing linear for the calf.
- Published
- 2016
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- View/download PDF
37. Bruising and Hemorrhagic Vesicles on the Tongue.
- Author
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Taylor NA, Lugo-Somolinos A, and Sayed CJ
- Subjects
- Aged, Amyloidosis pathology, Female, Humans, Immunoglobulin Light Chains metabolism, Immunoglobulin Light-chain Amyloidosis, Amyloidosis diagnosis, Contusions etiology, Hemorrhage etiology, Tongue pathology
- Published
- 2016
- Full Text
- View/download PDF
38. Overwhelming Physiological Regulation Through Personal Protection.
- Author
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Taylor NA
- Subjects
- Adaptation, Physiological, Cardiac Output physiology, Heat Stress Disorders physiopathology, Heat Stress Disorders prevention & control, Humans, Stress, Physiological, Sweating physiology, Blood Pressure physiology, Body Temperature Regulation physiology, Personal Protective Equipment, Protective Devices
- Abstract
There is often a fine line between providing appropriate personal protection and compromising capability. In some situations, protection must come first. In other circumstances, capability becomes paramount. In the military, mission-specific objectives can force personal protection to be less than ideal. Indeed, levels of protection appropriate within the civilian context could jeopardise health and operational success, and for operations conducted in the heat involving load carriage and armored protection with almost total-body clothing coverage, it is the likely thermal impediment to performance that perhaps first comes to mind. Although this consideration is appropriate, it may direct attention away from the actual cause of, and therefore preventative solutions to, physiological collapse. For instance, although classical heat illness absolutely occurs at the age extremes, and it may affect all people when air temperatures are exceptionally hot, frank hyperthermia is not generally the primary cause of exhaustion when healthy clothed individuals are working in the heat. Instead, another homoeostatic process is implicated; blood pressure regulation. In addition to participating in temperature regulation, the cardiovascular system supports oxygen delivery, blood pressure regulatory, and waste removal requirements. Therefore, the elevated cardiac output accompanying work must be shared. Accordingly, the case will be developed that thermoregulatory failure is often not the primary causal mechanism for soldier collapse, although such individuals may be hyperthermic. Alternatively, moderately, but not excessively, hyperthermic soldiers working under these conditions are perhaps more likely to collapse from cardiovascular insufficiency that precipitates uncompensable hypotension.
- Published
- 2015
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39. Perspectives on Aerobic and Strength Influences on Military Physical Readiness: Report of an International Military Physiology Roundtable.
- Author
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Friedl KE, Knapik JJ, Häkkinen K, Baumgartner N, Groeller H, Taylor NA, Duarte AF, Kyröläinen H, Jones BH, Kraemer WJ, and Nindl BC
- Subjects
- Female, Humans, Male, Sex Factors, United States, Military Personnel, Muscle Strength physiology, Physical Endurance physiology, Physical Fitness physiology, Resistance Training
- Abstract
Physical fitness training of military recruits is an enduring focus of armies. This is important for safe and effective performance of general tasks that anyone may have to perform in a military setting as well as preparation for more specialized training in specific job specialties. Decades of studies on occupationally specific physical requirements have characterized the dual aerobic and strength demands of typical military tasks; however, scientifically founded strategies to prepare recruits with a good mix of these 2 physiologically opposing capabilities have not been well established. High levels of aerobic training can compromise resistance training gains and increase injury rates. Resistance training requires a greater commitment of time and resources as well as a greater understanding of the science to produce true strength gains that may be beneficial to military performance. These are critical issues for modern armies with increased demands for well-prepared soldiers and fewer injury losses. The actual physical requirements tied to metrics of success in military jobs are also under renewed examination as women are increasingly integrated into military jobs previously performed only by men. At the third International Congress on Soldiers' Physical Performance, a roundtable of 10 physiologists with military expertise presented comparative perspectives on aerobic and strength training. These topics included the physiological basis of training benefits, how to train effectively, how to measure training effectiveness, considerations for the integration of women, and the big perspective. Key discussion points centered on (a) the significance of findings from research on integrated training, (b) strategies for effective strength development, and, ((c) injury reduction in training as well as the benefits of improved fitness to injury reduction across the force.)
- Published
- 2015
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40. Regional brain responses associated with thermogenic and psychogenic sweating events in humans.
- Author
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Farrell MJ, Trevaks D, Taylor NA, and McAllen RM
- Subjects
- Adult, Brain Mapping, Female, Galvanic Skin Response, Hot Temperature, Humans, Magnetic Resonance Imaging, Male, Skin Temperature, Stroop Test, Body Temperature, Brain physiology, Stress, Psychological physiopathology, Sweating
- Abstract
Sweating events occur in response to mental stress (psychogenic) or with increased body temperature (thermogenic). We previously found that both were linked to activation of common brain stem regions, suggesting that they share the same output pathways: a putative common premotor nucleus was identified in the rostral-lateral medulla (Farrell MJ, Trevaks D, Taylor NA, McAllen RM. Am J Physiol Regul Integr Comp Physiol 304: R810-R817, 2013). We therefore looked in higher brain regions for the neural basis that differentiates the two types of sweating event. Previous work has identified hemispheric activations linked to psychogenic sweating, but no corresponding data have been reported for thermogenic sweating. Galvanic skin responses were used to measure sweating events in two groups of subjects during either psychogenic sweating (n = 11, 35.3 ± 11.8 yr) or thermogenic sweating (n = 11, 34.4 ± 10.2 yr) while regional brain activation was measured by BOLD signals in a 3-Tesla MRI scanner. Common regions activated with sweating events in both groups included the anterior and posterior cingulate cortex, insula, premotor cortex, thalamus, lentiform nuclei, and cerebellum (P(corrected) < 0.05). Psychogenic sweating events were associated with significantly greater activation in the dorsal midcingulate cortex, parietal cortex, premotor cortex, occipital cortex, and cerebellum. No hemispheric region was found to show statistically significantly greater activation with thermogenic than with psychogenic sweating events. However, a discrete cluster of activation in the anterior hypothalamus/preoptic area was seen only with thermogenic sweating events. These findings suggest that the expected association between sweating events and brain regions implicated in "arousal" may apply selectively to psychogenic sweating; the neural basis for thermogenic sweating events may be subcortical., (Copyright © 2015 the American Physiological Society.)
- Published
- 2015
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41. Employment Standards for Australian Urban Firefighters: Part 2: The Physiological Demands and the Criterion Tasks.
- Author
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Taylor NA, Fullagar HH, Sampson JA, Notley SR, Burley SD, Lee DS, and Groeller H
- Subjects
- Adult, Australia, Female, Humans, Male, Middle Aged, Personnel Selection methods, Urban Population, Firefighters, Personnel Selection standards, Physical Fitness physiology, Task Performance and Analysis
- Abstract
Objective: The physiological demands of 15 essential, physically demanding fire-fighting tasks were investigated to identify criterion tasks for bona fide recruit selection., Methods: A total of 51 operational firefighters participated in discrete, field-based occupational simulations, with physiological responses measured throughout., Results: The most stressful tasks were identified and classified according to dominant fitness attributes and movement patterns. Three movement classes (single-sided load carriage [5 tasks], dragging loads [4 tasks], and overhead pushing and holding objects [2 tasks]) and one mandatory strength task emerged. Seven criterion tasks were identified. Load holding and carriage dominated these movement patterns, yet no task accentuated whole-body endurance., Conclusion: Material handling movements from each classification must appear within a physical aptitude (selection) test for it to adequately represent the breadth of tasks performed by Australian urban firefighters.
- Published
- 2015
- Full Text
- View/download PDF
42. Employment Standards for Australian Urban Firefighters: Part 3: The Transition From Criterion Task to Test.
- Author
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Groeller H, Fullagar HH, Sampson JA, Mott BJ, and Taylor NA
- Subjects
- Adult, Australia, Female, Humans, Male, Middle Aged, Personnel Selection methods, Reproducibility of Results, Urban Population, Firefighters, Personnel Selection standards, Physical Fitness, Task Performance and Analysis
- Abstract
Objective: In this third communication, the processes for converting criterion occupational tasks into bona fide pre-employment selection tests are presented using urban firefighters as the worked example., Methods: A total of 14 individuals participated in potential screening tests that targeted three loaded movement categories: single-sided load carriage (4 tests), dragging loads (2 tests), and overhead pushing and holding objects (5 tests)., Results: Seven tests emerged, one performed as an isolated pass/fail barrier test (ladder raise) and six incorporated into a sequential, timed circuit simulating hazmat incidents, ventilation fan carriage (stairs), motor-vehicle rescues, bushfire incidents, fire attacks, and a firefighter rescue., Conclusion: Because three tests provided predicted performance speeds to replicate the oxygen cost of firefighters performing the corresponding occupational simulations, notional performance thresholds could be projected and recommended for the final phase of this research.
- Published
- 2015
- Full Text
- View/download PDF
43. Employment Standards for Australian Urban Firefighters: Part 1: The Essential, Physically Demanding Tasks.
- Author
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Taylor NA, Fullagar HH, Mott BJ, Sampson JA, and Groeller H
- Subjects
- Adolescent, Adult, Aged, Australia, Decision Support Techniques, Employee Performance Appraisal methods, Female, Focus Groups, Humans, Male, Middle Aged, Personnel Selection methods, Surveys and Questionnaires, Urban Population, Young Adult, Employee Performance Appraisal standards, Firefighters, Personnel Selection standards, Physical Fitness, Task Performance and Analysis, Work Performance standards
- Abstract
Objective: This communication is the first of four describing the development of defensible firefighter-selection tests. The purpose was to identify a subset of essential, physically demanding tasks performed by contemporary urban firefighters., Methods: From existing procedural documentation and job analyses, 11 fire-station visits and interviews with 106 firefighters, and one focus-group meeting, 31 physically demanding tasks were identified and incorporated into a workforce survey. Using this tool, firefighters rated the importance, perceived difficulty, typical task durations, and annual performance frequency of each task., Results: Data from 989 respondents were analyzed, enabling a consolidation of these tasks into a subset of essential activities., Conclusions: These processes yielded a content-valid list of 15 essential, physically demanding tasks covering the full width of duties performed by urban firefighters from Australia's largest fire and rescue organization.
- Published
- 2015
- Full Text
- View/download PDF
44. Employment Standards for Australian Urban Firefighters: Part 4: Physical Aptitude Tests and Standards.
- Author
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Fullagar HH, Sampson JA, Mott BJ, Burdon CA, Taylor NA, and Groeller H
- Subjects
- Adolescent, Adult, Age Factors, Australia, Female, Humans, Male, Middle Aged, Personnel Selection methods, Sex Factors, Urban Population, Young Adult, Firefighters, Personnel Selection standards, Physical Fitness physiology, Task Performance and Analysis
- Abstract
Objective: Firefighter physical aptitude tests were administered to unskilled subjects and operational firefighters to evaluate the impact that testing bias associated with gender, age, activity-specific skills, or task familiarity may have upon establishing performance thresholds., Methods: These tests were administered in sequence, simulating hazmat incidents, ventilation fan carriage (stairs), motor-vehicle rescues, bushfire incidents, fire attacks, and a firefighter rescue. Participants included two unskilled samples (N = 14 and 22) and 143 firefighters., Results: Firefighter performance was not significantly different from the unskilled subjects. Participants from both genders passed the test, with scores unrelated to performance skill or age; however, familiarization significantly improved performance when the test was repeated., Conclusion: These outcomes confirmed this test to be gender-, age-, and skill-neutral. Familiarization effects could be removed through performing a single, pre-selection trial of the test battery.
- Published
- 2015
- Full Text
- View/download PDF
45. Thermal performance trials on the habitability of private bushfire shelters: part 2.
- Author
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Taylor NA and Haberley BJ
- Subjects
- Adult, Carbon Dioxide analysis, Dehydration physiopathology, Female, Fever physiopathology, Heart Rate, Humans, Humidity, Male, Oxygen analysis, Temperature, Ventilation, Young Adult, Body Temperature, Emergency Shelter, Fires
- Abstract
In the preceding communication, an investigation was described in which the thermal specifications for the design of private bushfire shelters were evaluated. Since those trials were undertaken with the thermal characteristics of the air clamped, survival uncertainty persisted if the internal ambient conditions were progressively changing, as would occur within an air-tight shelter. Therefore, two further investigations were performed. In the first, changes in the physical properties of air within an air-tight shelter simulator (1.2 m(3)), initially equilibrated to 43.7 °C and 42.3 % relative humidity, were studied when pre-heated, well-hydrated males were sealed inside (N = 16; 60 min; experimental series 2). Air temperature and humidity moved sigmoidally to 40.5 °C (standard deviation (SD), 0.5) and 90.1 % (SD, 2.1). Oxygen and carbon dioxide fractional concentrations changed reciprocally, with respective terminal averages of 16.7 % (SD, 0.8) and 3.94 % (SD, 0.72). Deep-body temperature rose beyond the tenth minute to a terminal mean of 39.3 °C (SD, 0.2). In the third experimental series, these air temperature and humidity changes were reproduced in trials commencing at two different thermal states (40 °C and 70 % relative humidity; 45 °C and 50 % relative humidity). Sixteen pre-heated and slightly dehydrated men and women were investigated. In neither condition did the auditory canal temperature of any individual change by more than 2 °C or exceed 40 °C. It may be concluded, within the limits of these experiments, that the recommended thermal and dimensional specifications for bushfire shelters can provide tenable conditions for healthy, young adults.
- Published
- 2015
- Full Text
- View/download PDF
46. Thermal performance trials on the habitability of private bushfire shelters: part 1.
- Author
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Taylor NA, Haberley BJ, and Hoyle DJ
- Subjects
- Adult, Australia, Dehydration physiopathology, Female, Heart Rate, Humans, Humidity, Male, Temperature, Young Adult, Body Temperature, Emergency Shelter, Fires
- Abstract
This communication is the first of two in which specifications for private bushfire shelters were evaluated during human trials. The purpose of this investigation (series 1) was to test the hypothesis that shelters capable of maintaining the internal environment at, or below, a modified discomfort index of 39 °C would prevent a deep-body temperature elevation of >2 °C. This was tested over 96 trials during which eight men and eight women were exposed at rest (60 min) to three regulated shelter conditions satisfying that standard: 40 °C and 70 % relative humidity, 45 °C and 50 % relative humidity and 50 °C and 30 % relative humidity. Subjects were tested twice in each condition following exercise- and heat-induced dehydration (2 % body mass reduction) and pre-heating to each of two deep-body thermal states (37.5 and 38.5 °C). Participants presented well rested and euhydrated, and pre-treatments successfully achieved the thermal and hydration targets prior to exposure. Auditory canal temperatures declined as exposures commenced, with subsequent rises of >0.5 °C not evident within any trial. However, each increment in air temperature elicited a significant elevation in the respective within-trial mean auditory canal temperature (37.4, 37.7 and 37.9 °C) and heart rate (103, 116 and 122 beats.min(-1)) when subjects were moderately hyperthermic (all P < 0.05). Nevertheless, on average, subjects successfully defended deep-body temperature at levels significantly below those associated with heat illness, and it was concluded that this thermal specification for bushfire shelters appeared adequate, providing the physical characteristics of the internal air remained stable.
- Published
- 2015
- Full Text
- View/download PDF
47. A Retrospective Evaluation of Injuries to Australian Urban Firefighters (2003 to 2012): Injury Types, Locations, and Causal Mechanisms.
- Author
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Taylor NA, Dodd MJ, Taylor EA, and Donohoe AM
- Subjects
- Adult, Aged, Benchmarking, Causality, Female, Humans, Male, Middle Aged, New South Wales epidemiology, Retrospective Studies, Risk Factors, Workers' Compensation, Accidents, Occupational statistics & numerical data, Firefighters
- Abstract
Objective: Benchmark data were sought for evaluating injury trends within Australian firefighters., Methods: Work-related injury data from Australia's largest urban fire and rescue organization were analyzed (2003 to 2012), with an emphasis on classification (occurrence, mechanism, agency, nature, and location) and demographic details., Results: Firefighters were injured on 6997 occasions (177 injuries per annum per 1000 full-time employees). The largest causal mechanism was muscular stress (74 injuries per 1000 full-time employees annually), with 62.1% of those incidents involving materials handling and slips, trips, and falls. No single mechanism could explain more than 20% of the injuries. The principal injury type involved sprains and strains. The most commonly injured sites were the knee, lower back, shoulder, and ankle., Conclusions: These observations provide a basis for intervention strategies that target sprains and strains associated with materials handling and slips, trips, and falls.
- Published
- 2015
- Full Text
- View/download PDF
48. What do firefighters desire from the next generation of personal protective equipment? Outcomes from an international survey.
- Author
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Lee JY, Park J, Park H, Coca A, Kim JH, Taylor NA, Son SY, and Tochihara Y
- Subjects
- Adult, Australia, Consumer Behavior, Female, Humans, Japan, Male, Middle Aged, Republic of Korea, Surveys and Questionnaires, United States, Young Adult, Firefighters, Personal Protective Equipment
- Abstract
The purpose of this study was to investigate smart features required for the next generation of personal protective equipment (PPE) for firefighters in Australia, Korea, Japan, and the USA. Questionnaire responses were obtained from 167 Australian, 351 Japanese, 413 Korean, and 763 U.S. firefighters (1,611 males and 61 females). Preferences concerning smart features varied among countries, with 27% of Korean and 30% of U.S. firefighters identifying 'a location monitoring system' as the most important element. On the other hand, 43% of Japanese firefighters preferred 'an automatic body cooling system' while 21% of the Australian firefighters selected equally 'an automatic body cooling system' and 'a wireless communication system'. When asked to rank these elements in descending priority, responses across these countries were very similar with the following items ranked highest: 'a location monitoring system', 'an automatic body cooling system', 'a wireless communication system', and 'a vision support system'. The least preferred elements were 'an automatic body warming system' and 'a voice recording system'. No preferential relationship was apparent for age, work experience, gender or anthropometric characteristics. These results have implications for the development of the next generation of PPE along with the international standardisation of the smart PPE.
- Published
- 2015
- Full Text
- View/download PDF
49. Temporal and thermal variations in site-specific thermoregulatory sudomotor thresholds: precursor versus discharged sweat production.
- Author
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Machado-Moreira CA, Barry RJ, Vosselman MJ, Ruest RM, and Taylor NA
- Subjects
- Adult, Ear Canal physiology, Female, Humans, Male, Sweat Glands innervation, Sweat Glands metabolism, Sweat Glands physiology, Young Adult, Body Temperature physiology, Body Temperature Regulation physiology
- Abstract
Temporal and thermal differences between the initiation of precursor, eccrine sweat and its surface discharge were investigated during passive heating. Sudomotor activity was evaluated using electrodermal (precursor) and ventilated sweat capsule measurements (dorsal fingers, dorsal hand, forehead, forearm). Passive heating significantly elevated auditory canal (0.5 degrees C) and mean body temperatures (0.9 degrees C). At each site, the precursor sudomotor thresholds occurred at a lower mean body temperature (P < .05), with an average elevation of 0.35 degrees C (SD 0.04). However, discharged thresholds were delayed until this temperature had risen 0.53 degrees C (SD 0.04), producing significant phase delays across sites (mean: 4.1 min [SD 0.5]; P < .05). It is concluded that precise sudomotor threshold determinations require methods that respond to sweat accumulating within the secretory coil, and not discharged secretions, reinforcing the importance of electrodermal techniques., (Copyright © 2014 Society for Psychophysiological Research.)
- Published
- 2015
- Full Text
- View/download PDF
50. The utility of heart rate and minute ventilation as predictors of whole-body metabolic rate during occupational simulations involving load carriage.
- Author
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Notley SR, Peoples GE, and Taylor NA
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Young Adult, Energy Metabolism, Firefighters, Heart Rate, Oxygen Consumption, Respiratory Rate, Weight-Bearing
- Abstract
The utility of cardiac and ventilatory predictors of metabolic rate derived under temperate and heated laboratory conditions was evaluated during three fire-fighting simulations (70-mm hose drag, Hazmat recovery, bushfire hose drag; N = 16 per simulation). The limits of agreement for cardiac (temperate: - 0.54 to 1.77; heated: - 1.39 to 0.80 l min(- 1)) and ventilatory surrogates (temperate: - 0.19 to 1.27; heated: - 0.26 to 1.16 l min(- 1)) revealed an over-estimation of oxygen consumption that exceeded the acceptable limits required by occupational physiologists (N = 25; ± 0.24 l min(- 1)). Although ventilatory predictions offered superior precision during low-intensity work (P < 0.05), a cardiac prediction was superior during more demanding work (P < 0.05). Deriving those equations under heated conditions failed to improve precision, with the exception of the cardiac surrogate during low-intensity work (P < 0.05). These observations imply that individualised prediction curves are necessary for valid estimations of metabolic demand in the field.
- Published
- 2015
- Full Text
- View/download PDF
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