Search

Objective: The telemedicine expansion (TE) that accompanied the COVID-19 pandemic presents a novel opportunity to increase access to care for rural-residing children with type 1 diabetes (T1D) who may live a great distance from their provider. The study objective was to compare trends in visit frequency among the pediatric T1D population at a single academic center in Oregon before and after TE by those living <100 miles versus ≥100 miles from clinic (MFC) and those residing in urban versus rural areas. Research Design and Methods: We evaluated electronic health record data from 790 children receiving care between July 2018 and December 2021. We estimated differences in likelihood of adequately timed monitoring care (ATMC) over time by patient residence using Generalized Estimating Equations. Results: Just before TE, 37.3% of children were receiving ATMC and those living ≥100 MFC were 20.6% less likely to receive ATMC compared with those living <100 MFC (relative risk [RR] 0.79; confidence interval [95% CI]: 0.57–1.11). Following TE, decreases in ATMC for those living ≥100 MFC were less than for those living <100 MFC (RR of interaction: 1.17; 95% CI: 0.68–2.00). Just before TE, those living in rural areas were as likely to receive ATMC compared with those living in urban areas (RR 1.00; 95% CI: 0.61–1.63). Following TE, decreases in ATMC were greater for those living in rural areas versus urban areas (RR of interaction: 0.79; 95% CI: 0.31–2.01). Conclusions: Between July 2020 and December 2021, the likelihood of ATMC decreased across the entire pediatric T1D population. Decreases in ATMC during this period were more substantial for those living <100 MFC and/or in rural areas, however, these discrepancies were not statistically significant. [ABSTRACT FROM AUTHOR]

The article discusses the importance of early protocol assessment in the design of decentralized clinical trials (DCTs), emphasizing considerations such as patient burden, and regulatory compliance to optimize trial design. Topics include assessing trial phases for decentralization suitability, incorporating patient voices during indication and participant population assessment, and planning for varying guidelines and regulations across different countries to avoid mid-trial amendments.

Forest fragmentation and introduced pathogens are negatively impacting trees and forests globally, including the Carolinian forest of southern Ontario, Canada. Multiple species at risk live in this threatened but biodiverse forest, including the endangered Cornus florida (eastern flowering dogwood), which is now limited to fragmented woodlots, and has been decimated by the introduced fungal pathogen Discula destructiva (dogwood anthracnose). Ongoing management of C. florida in Canada is challenged by multiple knowledge gaps, two of which we aimed to address in this study. We first evaluated the association between anthracnose disease prevalence and a suite of ecological and environmental variables across 21 sites. Across our sites, larger trees tended to have the highest disease incidence, and trees on shallow slopes had the most crown dieback. We then quantified genetic diversity and gene flow, and found that genetic structure has not been substantially impacted by habitat fragmentation, although dispersal typically covers short distances. However, genetic diversity is relatively low in smaller populations and in younger trees. Localized dispersal and eroding genetic diversity may limit future adaptation and hence exacerbate population declines. We recommend that managers prioritize plantings in small populations, avoid shallow slopes, and track younger trees to evaluate age-related mortality. [ABSTRACT FROM AUTHOR]

Objective: To assess the feasibility of applying machine learning (ML) methods to imputation in the Medical Expenditure Panel Survey (MEPS). Data Sources: All data come from the 2016–2017 MEPS. Study Design: Currently, expenditures for medical encounters in the MEPS are imputed with a predictive mean matching (PMM) algorithm in which a linear regression model is used to predict expenditures for events with (donors) and without (recipients) data. Recipient events and donor events are then matched based on the smallest distance between predicted expenditures, and the donor event's expenditures are used as the recipient event's imputation. We replace linear regression algorithm in the PMM framework with ML methods to predict expenditures. We examine five alternatives to linear regression: Gradient Boosting, Random Forests, Extreme Random Forests, Deep Neural Networks, and a Stacked Ensemble approach. Additionally, we introduce an alternative matching scheme, which matches on a vector of predicted expenditures by sources of payment instead of a single total expenditure prediction to generate potentially superior matches. Data Collection: Study data is derived from a large federal survey. Principal Findings: ML algorithms perform better at both prediction and matching imputation than Ordinary Least Squares (OLS), the most common prediction algorithm used in PMM. On average, the Stacked Ensemble approach that combines all the ML algorithms performs best, improving expenditure prediction R2 by 108% (0.156 points) and final imputation R2 by 227% (0.397 points). Matching on a prediction vector also improves alignment of sources of payments between donor and recipient events. Conclusions: ML algorithms and an alternative matching scheme improve the overall quality of expenditure PMM imputation in the MEPS. These methods may have additional value in other national surveys that currently rely on PMM or similar methods for imputation. [ABSTRACT FROM AUTHOR]

The rise of animals across the Ediacaran–Cambrian transition marked a step-change in the history of life, from a microbially dominated world to the complex macroscopic biosphere we see today. 1,2,3 While the importance of bioturbation and swimming in altering the structure and function of Earth systems is well established, 4,5,6 the influence of epifaunal animals on the hydrodynamics of marine environments is not well understood. Of particular interest are the oldest "marine animal forests," 7 which comprise a diversity of sessile soft-bodied organisms dominated by the fractally branching rangeomorphs. 8,9 Typified by fossil assemblages from the Ediacaran of Mistaken Point, Newfoundland, 8,10,11 these ancient communities might have played a pivotal role in structuring marine environments, similar to modern ecosystems, 7,12,13 but our understanding of how they impacted fluid flow in the water column is limited. Here, we use ecological modeling and computational flow simulations to explore how Ediacaran marine animal forests influenced their surrounding environment. Our results reveal how organism morphology and community structure and composition combined to impact vertical mixing of the surrounding water. We find that Mistaken Point communities were capable of generating high-mixing conditions, thereby likely promoting gas and nutrient transport within the "canopy." This mixing could have served to enhance local-scale oxygen concentrations and redistribute resources like dissolved organic carbon. Our work suggests that Ediacaran marine animal forests may have contributed to the ventilation of the oceans over 560 million years ago, well before the Cambrian explosion of animals. [Display omitted] • Ediacaran communities were capable of strongly mixing the surrounding water • Organism shape and size had the greatest influence on mixing patterns • Mixing could have influenced the distribution of water column resources like oxygen • Ediacaran communities may have contributed to the ventilation of the oceans Gutarra et al. use computer simulations of water flow to investigate the hydrodynamics of Ediacaran marine animal forests. The results reveal that some Ediacaran communities generated strong patterns of fluid mixing, which could have promoted gas and nutrient transport and thereby enhanced local oxygen concentrations. [ABSTRACT FROM AUTHOR]

The West Atlantic trumpetfish (Aulostomus maculatus) performs an unusual hunting strategy, termed shadowing, whereby a trumpetfish swims closely behind or next to another 'host' species to facilitate the capture of prey. Despite trumpetfish being observed throughout the Caribbean, observations of this behaviour appear to be concentrated to a handful of localities. Here we assess the degree of geographical clustering of shadowing behaviour throughout the Caribbean Sea, and identify ecological features associated with the likelihood of its occurrence. To do this, we used a citizen science approach by creating and distributing an online survey to target frequent divers across this region. While the vast majority of participants observed trumpetfish on nearly every dive across the Caribbean, using random labelling spatial analyses, we found the frequency of shadowing behaviour was geographically clustered; participants that were within ~ 120 km of each other reported observations of shadowing that were more similar than would be expected by chance. Our survey also highlighted that trumpetfish were more likely to be observed shadowing than observed alone in a particular habitat type, and with particular host species, suggesting potential ecological factors that could drive the uneven distribution of this behaviour. Our results demonstrate that this behavioural hunting strategy is spatially clustered and, more generally, highlight the power of using citizen science to investigate variation in animal behaviour over thousands of square kilometres. [ABSTRACT FROM AUTHOR]

Corals are powerful ecosystem engineers and can form reef communities with extraordinary biodiversity through time. Understanding the processes underlying the spatial distribution of corals allows us to identify the key biological and physical processes that structure coral communities and how these processes and interactions have evolved. However, few spatial ecology studies have been conducted on coral assemblages in the fossil record. Here we use spatial point process analysis (SPPA) to investigate the ecological interactions of an in situ tabulate and rugose coral community (n = 199), preserved under volcanic ash in the Silurian of Ireland. SPPA is able to identify many different sorts of interactions including dispersal limitation and competition within and between taxa. Our SPPA found that the spatial distribution of rugose corals were best modelled by Thomas clusters (pd = 0.834), indicating a single dispersal episode and that the tabulate corals were best modelled by double Thomas clusters (pd = 0.820), indicating two dispersal episodes. Further, the bivariate distribution was best modelled by linked double clusters (pd = 0.970), giving significant evidence of facilitation between the tabulate and rugose populations, and identifying the facilitators in this community to be the tabulate corals. This interaction could be an important ecological driver for enabling the aggregation of sessile organisms over long temporal periods and facilitation may help to explain trends in reef diversity and abundance during the Ordovician biodiversification and in the early Silurian. [ABSTRACT FROM AUTHOR]

Measuring a biomarker in pooled samples from multiple cases or controls can lead to cost-effective estimation of a covariate-adjusted odds ratio, particularly for expensive assays. But pooled measurements may be affected by assay-related measurement error (ME) and/or pooling-related processing error (PE), which can induce bias if ignored. Building on recently developed methods for a normal biomarker subject to additive errors, we present two related estimators for a right-skewed biomarker subject to multiplicative errors: one based on logistic regression and the other based on a Gamma discriminant function model. Applied to a reproductive health dataset with a right-skewed cytokine measured in pools of size 1 and 2, both methods suggest no association with spontaneous abortion. The fitted models indicate little ME but fairly severe PE, the latter of which is much too large to ignore. Simulations mimicking these data with a non-unity odds ratio confirm validity of the estimators and illustrate how PE can detract from pooling-related gains in statistical efficiency. These methods address a key issue associated with the homogeneous pools study design and should facilitate valid odds ratio estimation at a lower cost in a wide range of scenarios. [ABSTRACT FROM AUTHOR]

Robust time-series of direct observations of jellyfish abundance are not available for many ecosystems, leaving it difficult to determine changes in jellyfish abundance, the possible causes (e.g. climate change) or the consequences (e.g. trophic cascades). We sought an indirect ecological route to reconstruct jellyfish abundance in the Irish Sea: since zooplankton are jellyfish prey, historic variability in zooplankton communities may provide proxies for jellyfish abundance. We determined the Bayesian ecological network of jellyfish–zooplankton dependencies using jellyfish- and zooplankton-abundance data obtained using nets during a 2-week cruise to the Irish Sea in 2008. This network revealed that Aurelia aurita abundance was dependent on zooplankton groups Warm Temperate and Temperate Oceanic as defined by previous zooplankton ecology work. We then determined historic zooplankton networks across the Irish Sea from abundance data from Continuous Plankton Recorder surveys conducted between 1970 and 2000. Transposing the 2008 spatial dependencies onto the historic networks revealed that Aurelia abundance was more strongly dependent over time on sea surface temperature than on the zooplankton community. The generalist predatory abilities of Aurelia may have insulated this jellyfish over the 1985 regime shift when zooplankton composition in the Irish Sea changed abruptly, and also help explain its globally widespread distribution. [ABSTRACT FROM AUTHOR]

Most children with developmental disabilities (DD), such as intellectual disabilities and autism, live in low- and middle-income countries (LMICs), where services are usually limited. Various governmental, non-governmental and research organisations in LMICs have developed awareness-raising campaigns and training and education resources on DD in childhood relevant to LMICs. This study aimed to comprehensively search and review freely available materials in the academic and grey literature, aimed at awareness raising, training and education on DD among non-specialist professionals and community members in LMICs. We consulted 183 experts, conducted key-word searches in five academic databases, four grey-literature databases and seventeen customised Google search engines. Following initial screening, we manually searched relevant systematic reviews and lists of resources and conducted forwards and backwards citation checks of included articles. We identified 7327 articles and resources after deduplication. We then used a rigorous multi-step screening process to select 78 training resources on DD relevant to LMICs, of which 43 aimed at informing and/or raising awareness DD, 16 highlighted specific strategies for staff in health settings and 19 in education settings. Our mapping analysis revealed that a wealth of materials is available for both global and local use, including comics, children's books, flyers, posters, fact sheets, blogs, videos, websites pages, social media channels, handbooks and self-education guides, and training programmes or sessions. Twelve resources were developed for cross-continental or global use in LMICs, 19 were developed for and/or used in Africa, 23 in Asia, 24 in Latin America. Most resources were developed within the context where they were intended to be used. Identified gaps included a limited range of resources on intellectual disabilities, manuals for actively delivering training to staff in education settings and resources targeted at eastern European LMICs: future intervention development and adaptation efforts should address such gaps, to ensure capacity building materials exist for a sufficient variety of DD, settings and geographical areas. Beyond identifying these gaps, the value of the review lies in the compilation of summary tables of information on all freely available resources found, to support their selection and use in wider contexts. Information on the resource content, country of original development and copyright is provided to facilitate resource sharing and uptake. [ABSTRACT FROM AUTHOR]

The relative influence of niche vs. neutral processes in ecosystem dynamics is an on‐going debate, but the extent to which they structured the earliest animal communities is unknown. Some of the oldest known metazoan‐dominated paleocommunities occur in Ediacaran age (~ 565 million years old) strata in Newfoundland, Canada and Charnwood Forest, UK. These comprise large and diverse populations of sessile organisms that are amenable to spatial point process analyses, enabling inference of the most likely underlying niche or neutral processes governing community structure. We mapped seven Ediacaran paleocommunities using LiDAR, photogrammetry and a laser line probe. We found that neutral processes dominate these paleocommunities, with niche processes exerting limited influence, in contrast with the niche‐dominated dynamics of modern marine ecosystems. The dominance of neutral processes suggests that early metazoan diversification may not have been driven by systematic adaptations to the local environment, but instead may have resulted from stochastic demographic differences. [ABSTRACT FROM AUTHOR]

Coral is an invertebrate animal that acts as a colony of individuals (polyps), for the purpose of reef building. In the case of "hard corals", the polyps aggregate and create a "hard" exoskeleton. This exoskeleton has a symbiotic relationship with zooxanthellae algae that reside with the hard tissues. This symbiosis allows the algae to use the coral's waste for photosynthesis and the coral uses the algal products for maintenance. A delicate relationship that dictates the life history of both organisms. The Crown of Thoms Sea Star (Acanthaster planci) is a predatory sea starfish that feeds on the polyps of most species of coral. The starfish can grow quite large (~ lmeter in diameter) and can consume up to 10 square meters of coral per annum. Although natural predators include the giant triton snail, the titan trigger fish, and several species of pufferfish and shrimp, the starfish is covered in venomous spines, so these predators are not very common. Since the 1960's, periodic population increases/outbreaks of the Crown of Thoms starfish have impacted the Great Barrier Reef ecosystem off the coast of Australia. An outbreak being defined by a population density of greater than 15 starfish per hectare. Starfish populations of this density can result in over 90% of the coral being stripped from the reef. Studies have shown that multiple factors affect the starfish population spikes, the most notable being human overfishing of the starfish predators, and human-induced nutrient spikes. In particular, nutrient spikes lead to more successful starfish larvae which, in turn results in a large number of starfish juveniles reaching maturity. In this StoryMap presentation, a time-series of heatmaps are used to demonstrate the delicate relationship between human activity, starfish population density, and coral distribution. The heatmaps demonstrate that there is a relationship between the anthropogenic activities and population spikes of the starfish and a subsequent decline in the coral reef. Surveys indicate that a healthy reef can recover within a 10 -- 20 year window. However, with increasing frequencies of starfish population spikes along with other environmental stressors, the corals may not be able to recover. [ABSTRACT FROM AUTHOR]

The objective of this study was to gain better insight into factors associated with the capture-related mortality rate in cheetahs. A link to an online questionnaire was sent to zoo and wildlife veterinarians through the Species Survival Plan Programme and European Endangered Species Programme coordinators and via the 'Wildlife VetNet' Google group forum. The questionnaire consisted of 50 questions relating to the veterinarians' country of residence and experience, the medicine combinations used, standard monitoring procedures, capture-related complications and mortalities experienced in this species under different capture conditions. In addition, necropsy data from the national wildlife disease database of the National Zoological Gardens of South Africa were examined for cases where anaesthetic death was listed as the cause of death in cheetahs. A total of 75 veterinarians completed the survey, with 38 from African countries and a combined total of 37 from Europe, the United States (US) and Asia. Of these, 24% (n = 18/75) had experienced at least one capture-associated cheetah mortality, with almost all of the fatalities (29/30) reported by veterinarians working in Africa. A lack of anaesthetic monitoring and the absence of supplemental oxygen were shown to be significant risk factors for mortality. Hyperthermia, likely to be associated with capture stress, was the most common reported complication (35%). The results suggest that free-ranging rather than habituated captive cheetahs are particularly at risk of dying during immobilisation and transport. The capture-related fatalities in this species do not appear to be associated with either the veterinarian's level of clinical experience or the immobilisation agents used. [ABSTRACT FROM AUTHOR]

In a multivariable logistic regression setting where measuring a continuous exposure requires an expensive assay, a design in which the biomarker is measured in pooled samples from multiple subjects can be very cost effective. A logistic regression model for poolwise data is available, but validity requires that the assay yields the precise mean exposure for members of each pool. To account for errors, we assume the assay returns the true mean exposure plus a measurement error (ME) and/or a processing error (PE). We pursue likelihood-based inference for a binary health-related outcome modeled by logistic regression coupled with a normal linear model relating individual-level exposure to covariates and assuming that the ME and PE components are independent and normally distributed regardless of pool size. We compare this approach with a discriminant function-based alternative, and we demonstrate the potential value of incorporating replicates into the study design. Applied to a reproductive health dataset with pools of size 2 along with individual samples and replicates, the model fit with both ME and PE had a lower AIC than a model accounting for ME only. Relative to ignoring errors, this model suggested a somewhat higher (though still nonsignificant) adjusted log-odds ratio associating the cytokine MCP-1 with risk of spontaneous abortion. Simulations modeled after these data confirm validity of the methods, demonstrate how ME and particularly PE can reduce the efficiency advantage of a pooling design, and highlight the value of replicates in improving stability when both errors are present. [ABSTRACT FROM AUTHOR]

Rangeomorphs dominate the Ediacaran Avalonian macrofossil assemblages of Charnwood Forest, UK (∼562 Ma). However, their unfamiliar fractal architecture makes distinguishing phylogenetically reliable characters from intraspecific features difficult. Fortunately, spatial analysis of large in-situ populations offers an independent means of assessing their taxonomy. Populations of a single biological species are likely to exhibit similar spatial distributions due to their shared responses to the biological and ecological processes acting upon them. As such, spatial analyses can be used to interrogate which are the most taxonomically deductive characters in similar species. We used random labelling analyses to investigate the presence or absence of characters of Primocandelabrum boyntoni, P.aethelfalaedia, and P.aelfwynnia on the Bed 'B'. The resultant spatial distributions were compared to observed characters using goodness-of-fit tests to determine which characters were associated with unique populations, and which were found across multiple populations. We found that P.boyntoni and P.aelfwynnia had statistically indistinguishable character distributions, suggesting that they represent a single biological species, and that they exhibited significantly different distributions to P.aethelfalaedia, suggesting that there are two (rather than three) species of Primocandelabrum present on the B surface. Furthermore, we found that the distribution of concealed versus unconcealed 1st order branches across all specimens exhibited significantly different density-dependant behaviour, with unconcealed branching occurring in areas of higher density populations and concealed branching occurring in the lower density areas of Primocandelabrum. We speculate that unconcealed branches may have been a response to the reduced availability of resources in higher density areas, implying rangeomorphs were capable of ecophenotypic responses. [ABSTRACT FROM AUTHOR]

The sustainability of captive cheetah populations is limited by high mortality due to chronic renal disease. This necropsy study, conducted on 243 captive cheetahs from one institution, investigated the relationships between focal palatine erosions, gastritis, enterocolitis, glomerulosclerosis, chronic renal infarcts, renal cortical and medullary fibrosis, and renal medullary amyloidosis at death. Associations between the individual renal lesions and death due to chronic renal disease and comparisons of lesion prevalence between captive bred and wild born and between normal and king coated cheetahs were also assessed. All lesions were significantly positively correlated with age at death. Renal medullary fibrosis was the only lesion associated with the likelihood of death being due to chronic renal disease, and cheetahs with this lesion were younger, on average, than cheetahs with other renal lesions. Alimentary tract lesions were not associated with amyloidosis. All lesions, except for palatine erosions, were more common in wild born than in captive bred cheetahs; the former were older at death than the latter. Having a king coat had no clear effect on disease prevalence. These results suggest that age and renal medullary fibrosis are the primary factors influencing the pathogenesis of chronic renal disease in captive cheetahs. Apart from amyloidosis, these findings are analogous to those described in chronic renal disease in domestic cats, which is postulated to result primarily from repetitive hypoxic injury of renal tubules, mediated by age and stress. Cheetahs may be particularly susceptible to acute renal tubular injury due to their propensity for stress and their extended life span in captivity, as well as their adaptation for fecundity (rather than longevity) and adrenaline-mediated high speed prey chases. The presence of chronic renal disease in subadult cheetahs suggests that prevention, identification and mitigation of stress are critical to the successful prevention of chronic renal disease in captive cheetahs. [ABSTRACT FROM AUTHOR]

Epidemiologic studies are frequently susceptible to missing information. Omitting observations with missing variables remains a common strategy in epidemiologic studies, yet this simple approach can often severely bias parameter estimates of interest if the values are not missing completely at random. Even when missingness is completely random, complete-case analysis can reduce the efficiency of estimated parameters, because large amounts of available data are simply tossed out with the incomplete observations. Alternative methods for mitigating the influence of missing information, such as multiple imputation, are becoming an increasing popular strategy in order to retain all available information, reduce potential bias, and improve efficiency in parameter estimation. In this paper, we describe the theoretical underpinnings of multiple imputation, and we illustrate application of this method as part of a collaborative challenge to assess the performance of various techniques for dealing with missing data (Am J Epidemiol. 2018;187(3):568-575 ). We detail the steps necessary to perform multiple imputation on a subset of data from the Collaborative Perinatal Project (1959-1974), where the goal is to estimate the odds of spontaneous abortion associated with smoking during pregnancy. [ABSTRACT FROM AUTHOR]

We have investigated the effects of porosity on the crystallization kinetics of amorphous solid water (ASW). Porosity in ASW films, condensed from the vapor phase at varying incidences at 10 K, was characterized using ultraviolet-visible interferometry and quartz crystal microgravimetry. The films were heated to crystallization temperatures between 130 and 141 K, resulting in partial pore compaction. The isothermal phase transformation was characterized using transmission infrared spectroscopy to monitor the time evolution of the 3.1-µm O H stretch absorption band. We find that ASW crystallization unfolds in two distinct stages. The first stage, responsible for ∼10% transformation, is initiated from nucleation at the external surface. The dominant second stage begins with nucleation at the internal pore surfaces and completes the transformation of the film at a faster rate compared to the first stage. A key finding is that porosity has major influence on crystallization kinetics; a film with five-times-higher porosity was observed to crystallize ∼15 times faster, compared to the less porous counterpart. We extrapolate our results to predict crystallization times for amorphous ices condensed on Europa's surface from plume sources, as recently observed by the Hubble Space Telescope. [ABSTRACT FROM AUTHOR]

Growth of their college's off-campus and online course offerings led librarians at SUNY Oswego to run usability tests with off-campus students to compensate for a lack of responses from this population during earlier usability testing. Constraints on testing with off-campus students included lack of funding and librarian time, as well as difficulty in attracting student participation. A brief usability study that could be completed by students in the first 10 minutes of class was devised, consisting of a first click test, a survey question, and a top task analysis activity. The study was conducted with 22 students from a satellite-campus Master's in Education program. Discussion includes selecting appropriate tests, analysis of study results, and application of data for improving Website design and information literacy instruction in an academic library. [ABSTRACT FROM AUTHOR]

Pooling biospecimens prior to performing laboratory assays is a useful tool to reduce costs, achieve minimum volume requirements and mitigate assay measurement error. When estimating the risk of a continuous, pooled exposure on a binary outcome, specialized statistical techniques are required. Current methods include a regression calibration approach, where the expectation of the individual-level exposure is calculated by adjusting the observed pooled measurement with additional covariate data. While this method employs a linear regression calibration model, we propose an alternative model that can accommodate log-linear relationships between the exposure and predictive covariates. The proposed model permits direct estimation of the relative risk associated with a log-transformation of an exposure measured in pools. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Potential reductions in laboratory assay costs afforded by pooling equal aliquots of biospecimens have long been recognized in disease surveillance and epidemiological research and, more recently, have motivated design and analytic developments in regression settings. For example, Weinberg and Umbach (1999, Biometrics 55, 718-726) provided methods for fitting set-based logistic regression models to case-control data when a continuous exposure variable (e.g., a biomarker) is assayed on pooled specimens. We focus on improving estimation efficiency by utilizing available subject-specific information at the pool allocation stage. We find that a strategy that we call '(y, c)-pooling,' which forms pooling sets of individuals within strata defined jointly by the outcome and other covariates, provides more precise estimation of the risk parameters associated with those covariates than does pooling within strata defined only by the outcome. We review the approach to set-based analysis through offsets developed by Weinberg and Umbach in a recent correction to their original paper. We propose a method for variance estimation under this design and use simulations and a real-data example to illustrate the precision benefits of (y, c)-pooling relative to y-pooling. We also note and illustrate that set-based models permit estimation of covariate interactions with exposure. [ABSTRACT FROM AUTHOR]

Background: Studies examining total gestational weight gain (GWG) and outcomes associated with gestational age (GA) are potentially biased. The z-score has been proposed to mitigate this bias. We evaluated a regression-based adjustment for GA to remove the correlation between GWG and GA, and compared it to published weight-gain-for-gestational-age z-scores when applied to a study sample with different underlying population characteristics.Methods: Using 65 643 singleton deliveries to normal weight women at 12 US clinical sites, we simulated a null association between GWG and neonatal mortality. Logistic regression was used to estimate approximate relative risks (RR) of neonatal mortality associated with GWG, unadjusted and adjusted for GA, and the z-score, overall and within study sites. Average RRs across 5000 replicates were calculated with 95% coverage probability to indicate model bias and precision, where 95% is nominal.Results: Under a simulated null association, total GWG resulted in a biased mortality estimate (RR = 0.87; coverage = 0%); estimates adjusted for GA were unbiased (RR = 1.00; coverage = 94%). Quintile-specific RRs ranged from 0.97-1.03. Similar results were observed for site-specific analyses. The overall z-score RR was 0.97 (84% coverage) with quintile-specific RRs ranging from 0.64-0.90. Estimates were close to 1.0 at most sites, with coverage from 70-94%. Sites 1 and 6 were biased with RRs of 0.66 and 1.43, respectively, and coverage of 70% and 80%.Conclusions: Adjusting for GA achieves unbiased estimates of the association between total GWG and neonatal mortality, providing an accessible alternative to the weight-gain-for-gestational-age z-scores without requiring assumptions concerning underlying population characteristics. [ABSTRACT FROM AUTHOR]

Objective: To compare time to pregnancy and live birth among couples with varying intervals of pregnancy loss date to subsequent trying to conceive date.Methods: In this secondary analysis of the Effects of Aspirin in Gestation and Reproduction trial, 1,083 women aged 18-40 years with one to two prior early losses and whose last pregnancy outcome was a nonectopic or nonmolar loss were included. Participants were actively followed for up to six menstrual cycles and, for women achieving pregnancy, until pregnancy outcome. We calculated intervals as start of trying to conceive date minus pregnancy loss date. Time to pregnancy was defined as start of trying to conceive until subsequent conception. Discrete Cox models, accounting for left truncation and right censoring, estimated fecundability odds ratios (ORs) adjusting for age, race, body mass index, education, and subfertility. Although intervals were assessed prior to randomization and thus reasoned to have no relation with treatment assignment, additional adjustment for treatment was evaluated given that low-dose aspirin was previously shown to be predictive of time to pregnancy.Results: Couples with a 0-3-month interval (n=765 [76.7%]) compared with a greater than 3-month (n=233 [23.4%]) interval were more likely to achieve live birth (53.2% compared with 36.1%) with a significantly shorter time to pregnancy leading to live birth (median [interquartile range] five cycles [three, eight], adjusted fecundability OR 1.71 [95% confidence interval 1.30-2.25]). Additionally adjusting for low-dose aspirin treatment did not appreciably alter estimates.Conclusion: Our study supports the hypothesis that there is no physiologic evidence for delaying pregnancy attempt after an early loss. [ABSTRACT FROM AUTHOR]

Enigmatic macrofossils of late Ediacaran age (580-541 million years ago) provide the oldest known record of diverse complex organisms on Earth, lying between the microbially dominated ecosystems of the Proterozoic and the Cambrian emergence of the modern biosphere. Among the oldest and most enigmatic of these macrofossils are the Rangeomorpha, a group characterized by modular, self-similar branching and a sessile benthic habit. Localized occurrences of large in situ fossilized rangeomorph populations allow fundamental aspects of their biology to be resolved using spatial point process techniques. Here we use such techniques to identify recurrent clustering patterns in the rangeomorph Fractofusus, revealing a complex life history of multigenerational, stolon-like asexual reproduction, interspersed with dispersal by waterborne propagules. Ecologically, such a habit would have allowed both for the rapid colonization of a localized area and for transport to new, previously uncolonized areas. The capacity of Fractofusus to derive adult morphology by two distinct reproductive modes documents the sophistication of its underlying developmental biology. [ABSTRACT FROM AUTHOR]

Pooling biospecimens prior to performing lab assays can help reduce lab costs, preserve specimens, and reduce information loss when subject to a limit of detection. Because many biomarkers measured in epidemiological studies are positive and right-skewed, proper analysis of pooled specimens requires special methods. In this paper, we develop and compare parametric regression models for skewed outcome data subject to pooling, including a novel parameterization of the gamma distribution that takes full advantage of the gamma summation property. We also develop a Monte Carlo approximation of Akaike's Information Criterion applied to pooled data in order to guide model selection. Simulation studies and analysis of motivating data from the Collaborative Perinatal Project suggest that using Akaike's Information Criterion to select the best parametric model can help ensure valid inference and promote estimate precision. [ABSTRACT FROM AUTHOR]

Twenty-nine wild Cape sugarbirds ( Promerops cafer) died acutely after ingestion of a homemade xylitol nectar solution from a bird feeder. The most aggressive feeders were first affected. Most birds showed clinical signs within 15 minutes of nectar ingestion, including incoordination, weakness, falling from perches, collapse, and death. A few birds showing clinical signs seemed to spontaneously recover and fly away. Full necropsy examinations done on 27 birds were hampered by freezing artifact and autolysis, but results indicated death was caused by the consequences of acute hypoglycemia. A presumptive diagnosis of xylitol toxicity was made based on the history, clinical signs, and absence of other obvious causes of death. This is potentially the first record of xylitol toxicity in wild birds. [ABSTRACT FROM AUTHOR]

Pooling specimens prior to performing laboratory assays has various benefits. Pooling can help to reduce cost, preserve irreplaceable specimens, meet minimal volume requirements for certain lab tests, and even reduce information loss when a limit of detection is present. Regardless of the motivation for pooling, appropriate analytical techniques must be applied in order to obtain valid inference from composite specimens. When biomarkers are treated as the outcome in a regression model, techniques applicable to individually measured specimens may not be valid when measurements are taken from pooled specimens, particularly when the biomarker is positive and right skewed. In this paper, we propose a novel semiparametric estimation method based on an adaptation of the quasi-likelihood approach that can be applied to a right-skewed outcome subject to pooling. We use simulation studies to compare this method with an existing estimation technique that provides valid estimates only when pools are formed from specimens with identical predictor values. Simulation results and analysis of a motivating example demonstrate that, when appropriate estimation techniques are applied to strategically formed pools, valid and efficient estimation of the regression coefficients can be achieved. [ABSTRACT FROM AUTHOR]

The potential for research involving biospecimens can be hindered by the prohibitive cost of performing laboratory assays on individual samples. To mitigate this cost, strategies such as randomly selecting a portion of specimens for analysis or randomly pooling specimens prior to performing laboratory assays may be employed. These techniques, while effective in reducing cost, are often accompanied by a considerable loss of statistical efficiency. We propose a novel pooling strategy based on the k-means clustering algorithm to reduce laboratory costs while maintaining a high level of statistical efficiency when predictor variables are measured on all subjects, but the outcome of interest is assessed in pools. We perform simulations motivated by the BioCycle study to compare this k-means pooling strategy with current pooling and selection techniques under simple and multiple linear regression models. While all of the methods considered produce unbiased estimates and confidence intervals with appropriate coverage, pooling under k-means clustering provides the most precise estimates, closely approximating results from the full data and losing minimal precision as the total number of pools decreases. The benefits of k-means clustering evident in the simulation study are then applied to an analysis of the BioCycle dataset. In conclusion, when the number of lab tests is limited by budget, pooling specimens based on k-means clustering prior to performing lab assays can be an effective way to save money with minimal information loss in a regression setting. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The timing of the first appearance of animals is of crucial importance for understanding the evolution of life on Earth. Although the fossil record places the earliest metazoans at 572–602 Ma, molecular clock studies suggest a far earlier origination, as far back as ~850 Ma. The difference in these dates would place the rise of animal life into a time period punctuated by multiple colossal, potentially global, glacial events. Although the two schools of thought debate the limitations of each other's methods, little time has been dedicated to how animal life might have survived if it did arise before or during these global glacial periods. The history of recent polar biota shows that organisms have found ways of persisting on and around the ice of the Antarctic continent throughout the Last Glacial Maximum (33–14 Ka), with some endemic species present before the breakup of Gondwana (180–23 Ma). Here we discuss the survival strategies and habitats of modern polar marine organisms in environments analogous to those that could have existed during Neoproterozoic glaciations. We discuss how, despite the apparent harshness of many ice covered, sub‐zero, Antarctic marine habitats, animal life thrives on, in and under the ice. Ice dominated systems and processes make some local environments more habitable through water circulation, oxygenation, terrigenous nutrient input and novel habitats. We consider how the physical conditions of Neoproterozoic glaciations would likely have dramatically impacted conditions for potential life in the shallows and erased any possible fossil evidence from the continental shelves. The recent glacial cycle has driven the evolution of Antarctica's unique fauna by acting as a "diversity pump," and the same could be true for the late Proterozoic and the evolution of animal life on Earth, and the existence of life elsewhere in the universe on icy worlds or moons. [ABSTRACT FROM AUTHOR]

Epidemiological studies involving biomarkers are often hindered by prohibitively expensive laboratory tests. Strategically pooling specimens prior to performing these lab assays has been shown to effectively reduce cost with minimal information loss in a logistic regression setting. When the goal is to perform regression with a continuous biomarker as the outcome, regression analysis of pooled specimens may not be straightforward, particularly if the outcome is right-skewed. In such cases, we demonstrate that a slight modification of a standard multiple linear regression model for poolwise data can provide valid and precise coefficient estimates when pools are formed by combining biospecimens from subjects with identical covariate values. When these [ABSTRACT FROM AUTHOR]

This PRISMA scoping review explored worldwide research on the delivery of suicide-specific interventions through an exclusive telehealth modality. Research over telehealth modalities with suicidal individuals highlights the importance of facilitating participants' access to treatments despite location and circumstances (e.g., rural, expenses related to appointments, etc.). The review sought evidence of outcomes of trials or projects in which both the patient and therapist attended sessions conjointly and openly discussed suicide over a telehealth modality (e.g., phone, zoom). To explore this topic the authors searched for research trials and quality improvement projects using Ovid Medline, Ovid Embase, Ovid PsycINFO, EBSCO Social Services Abstracts, and Web of Science on 3/3/2021. Nine different articles were included that each spanned distinct treatments, with eight being research studies and one being a quality improvement project. Publications featuring ongoing or upcoming research in which complete study results were not available did not meet inclusion criteria for this review. Several important research gaps were identified. While this approach has been largely understudied, exclusive telehealth delivery of suicide-specific interventions has great potential for the prevention of suicidality, especially in the era of COVID-19 and beyond. [ABSTRACT FROM AUTHOR]

Recent advances in synthetic methods for the direct α-functionalization of saturated cyclic amines are described. Methods are categorized according to the in situ formed reactive intermediate (α-amino cation, α-amino anion, and α-amino radical). Transition-metal-catalyzed reactions involving other intermediates have been treated as a separate and fourth class. [ABSTRACT FROM AUTHOR]

Academic librarians at a mid-size university library developed an online information literacy tutorial that is easy to create, access, edit, and organize even for those with limited time and technological skills. Modular in structure, Project Information Literacy Online Tutorial (PILOT) includes interactive exercises, media, and self-testing as well as quizzes that can be graded. The original development of this tutorial was not without its difficulties, but has resulted in a product that is flexible, powerful, and freely available for adoption and/or adaptation by other libraries. [ABSTRACT FROM PUBLISHER]

The article focuses on the harp sonata of German musician and composer Carl Philipp Emanuel Bach and its influence to modern harp musicians. It notes that the solo sonatas of Bach were composed between 1735 and 1786 in Frankfurt, Berlin and Hamburg. It also mentions that Bach gave up his legal career to pursue music and was appointed to the service of the flute-playing king, Frederick II of Prussia, at the age of 24.

Abstract: A new cell concept has been developed that enables epitaxial c-Si thin-film solar cells to be made using isolating substrates. The Recrystallised Wafer-Equivalent on an Isolating Substrate (RexWISe) cell concept relies on an array of mini-silicon rods through the substrate to enable standard contacting. Processing techniques have been developed to produce the rods by drilling holes through the substrate, coating the holes with an intermediate layer, filling the holes with a seeding layer deposition and then recrystallising the seeding layer. Subsequently, the active layers of the cell are epitaxially grown onto the recrystallised layer and then this “Wafer-Equivalent” structure is metallised like a standard wafer solar cell. The first solar cells have been produced to test the RexWISe process and a “proof-of-concept” efficiency of almost 8% was achieved. [Copyright &y& Elsevier]

The easily synthesized, easily handled compound Pd(η3-1-PhC3H4)(η5-C5H5) (II) reacts readily with mono- and bidentate tertiary phosphines to produce the corresponding bis-phosphine palladium(O) complexes in good yields; II is thus an excellent precursor, perhaps the most efficacious and reliable available, for the synthesis of palladium(0) cross-coupling catalysts. [ABSTRACT FROM AUTHOR]

The short story "Vanishing Bicycle," by Emily Mitchell is presented.

The article presents comments from deans and directors of both conservatories and universities on the factors that need to be considered by students who wants to be educated in music. Dean of Music Robert Blocker of Yale University mentions the institutional distinctions, which include the kinds of program, amount of non-musical study and the learning experience. On the other hand, Dean Robert Cutietta of USC Thornton School of Music stresses the significance of the student's passion in music.

The article presents a guide to the difficulties of embellishing the Leopold Mozart Concerto. Confusion concerning the accurate interpretation of Mozart's appoggiaturas arose from the way Mozart noted a detached sixteenth note. In some cases, Mozart wrote out to the embellishments in the first published edition to show exactly how he wanted them played.

The first animals appear during the late Ediacaran (572 to 541 Ma); an initial diversity increase was followed reduction in diversity, often interpreted as catastrophic mass extinction. We investigate Ediacaran ecosystem structure changes over this time period using the "Elements of Metacommunity Structure" framework to assess whether this diversity reduction in the Nama was likely caused by an external mass extinction, or internal metacommunity restructuring. The oldest metacommunity was characterised by taxa with wide environmental tolerances, and limited specialisation or intertaxa associations. Structuring increased in the second oldest metacommunity, with groups of taxa sharing synchronous responses to environmental gradients, aggregating into distinct communities. This pattern strengthened in the youngest metacommunity, with communities showing strong environmental segregation and depth structure. Thus, metacommunity structure increased in complexity, with increased specialisation and resulting in competitive exclusion, not a catastrophic environmental disaster, leading to diversity loss in the terminal Ediacaran. These results reveal that the complex eco-evolutionary dynamics associated with Cambrian diversification were established in the Ediacaran. This study shows that the eco-evolutionary dynamics of metazoan diversification known from the Cambrian Period started earlier in the Ediacaran Period with the Avalon assemblage and increased in complexity towards the Phanerozoic as new anatomical innovations appeared, culminating in the "Cambrian Explosion." [ABSTRACT FROM AUTHOR]