bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elucidating shark diets with DNA metabarcoding from cloacal swabs
Authors: van Zinnicq Bergmann Maurits P. M. , Postaire Bautisse D. , Gastrich Kirk , Heithaus Michael R. , Hoopes Lisa A. , Lyons Kady , Papastamatiou Yannis P. , Schneider Eric V. C. , Strickland Bradley A. , Talwar Brendan S. , Chapman Demian D. , Bakker Judith 
Published: February 2021

AbstractAnimal dietary information provides the foundation for understanding trophic relationships, which is essential for ecosystem management. Yet, in marine systems, high‐resolution diet reconstruction tools are currently under‐developed. This is particularly pertinent for large marine vertebrates, for which direct foraging behaviour is difficult or impossible to observe and, due to their conservation status, the collection of stomach contents at adequate sample sizes is frequently impossible. Consequently, the diets of many groups, such as sharks, have largely remained unresolved. To address this knowledge gap, we applied metabarcoding to prey DNA in faecal residues (fDNA) collected on cotton swabs from the inside of a shark's cloaca. We used a previously published primer set targeting a small section of the 12S rRNA mitochondrial gene to amplify teleost prey species DNA. We tested the utility of this method in a controlled feeding experiment with captive juvenile lemon sharks (Negaprion brevirostris) and on free‐ranging juvenile bull sharks (Carcharhinus leucas). In the captive trial, we successfully isolated and correctly identified teleost prey DNA without incurring environmental DNA contamination from the surrounding seawater. In the field, we were able to reconstruct high‐resolution teleost dietary information from juvenile C. leucas fDNA that was generally consistent with expectations based on published diet studies of this species. While further investigation is needed to validate the method for larger sharks and other species, it is expected to be broadly applicable to aquatic vertebrates and provides an opportunity to advance our understanding of trophic interactions in marine and freshwater systems.
Variation of bacterial communities along the vertical gradient in Lake Issyk Kul, Kyrgyzstan
Authors: Rojas‐Jimenez Keilor , Araya‐Lobo Alex , Quesada‐Perez Fabio , Akerman‐Sanchez Johana , Delgado‐Duran Brayan , Ganzert Lars , Zavialov Peter O. , Alymkulov Salmor , Kirillin Georgiy , Grossart Hans‐Peter 
Published: February 2021

SummaryWe explored the diversity and community composition of bacteria along a vertical gradient in Lake Issyk Kul, Kyrgyzstan, one of the world's largest and deepest brackish lakes. We identified 4904 bacterial amplicon sequence variants based on the 16S rRNA gene analysis and determined significant changes in the composition, responding mainly to depth and salinity. A higher abundance of Proteobacteria and Bacteroidetes was observed in the surface waters and lake tributaries. Cyanobacteria were more abundant in the deep chlorophyll maximum from 28.5 to 128 m, while Planctomycetes and Chloroflexi were dominant in the deepest layers, from 128 to 600 m. According to our machine learning analyses, depth and temperature were the most critical environmental factors, with strong effects on Proteobacteria, Planctomycetes and Chloroflexi, while oxygen was associated with the variations in Cyanobacteria. We also observed that with increasing depth, the alpha diversity values increased. The dominance of Planctomycetes and Chloroflexi in the deepest layers can only be seen in a few lakes of the world. However, the lake is facing increasing anthropogenic and climatic pressure. There is an urgent need to understand better the ecological role and function of these unique deep‐water microbial communities.
Authority, Monitoring, and Incentives in Hierarchies*†
Authors: Hofmann Christian , Indjejikian Raffi J. 
Published: February 2021

ABSTRACTWe study three elements of management control: incentive compensation, performance monitoring, and delegation of authority to managers to contract with lower‐level employees. Using a principal‐agent model, we highlight important direct and indirect interactions between and among these endogenous control elements, themes often emphasized in the economics and accounting literatures using the analogy of a three‐legged stool. We identify circumstances in which control elements are complements or substitutes and exhibit a coherent pattern of practices observed together. For instance, contrary to typical predictions that quality monitoring complements steep effort incentives, we find that when contracting authority adjusts easily to changes in firm circumstances, then both incentive pay and contracting authority substitute for monitoring quality, while incentive pay complements contracting authority. Overall, our findings suggest a number of empirical implications and generally inform a growing literature that documents the presence or absence of complementarities among management control elements.
Evaluation of bedside sonography performed by emergency physicians to detect intussusception in children in the emergency department
Authors: Tonson la Tour Aude , Desjardins Marie Pier , Gravel Jocelyn 
Published: February 2021

AbstractObjectiveThe aim of our study was to evaluate the test characteristics of point‐of‐care ultrasound (POCUS) performed by emergency physicians with varying levels of experience among children having undergone diagnostic radiology ultrasound for intussusception in a pediatric emergency department (PED).MethodsThis was a subanalysis of a prospective cohort study conducted at a tertiary care PED. The study population was a sample of children younger than 5 years old who required an abdominal ultrasound for suspected intussusception. Participating physicians had varying levels of POCUS experience. They received a 1‐hour didactic and practical training session on intussusception ultrasound. All POCUS was performed following the initial physical examination and prior to further radiologic evaluation. The final outcome was determined by radiologic evaluation performed by a pediatric radiologist. Test characteristics were calculated for POCUS compared with the criterion standard of ultrasound read by a pediatric radiologist. A secondary analysis compared test characteristics of POCUS performed by physicians with different level of POCUS training.ResultsA total of 131 children were evaluated by POCUS, of whom 45 (34%) had an intussusception. Twenty‐four physicians performed between one and 25 POCUS procedures. POCUS identified 39 of 45 intussusception cases, with a sensitivity of 0.87 (95% confidence interval [CI] = 0.74 to 0.94). A normal or inconclusive POCUS was reported for 83 of the 86 negative studies, with a specificity of 0.97 (95% CI = 0.90 to 0.99). When excluding the 28 patients for whom the physician reported an inconclusive examination, the sensitivity improved to 0.98 (95% CI = 0.97 to 1.00) and the specificity to 0.94 (95% CI = 0.85 to 0.99). The accuracy of diagnosis using POCUS was 42 of 43 (98%) for experienced sonographers in comparison to 81 of 88 (92%) for novices.ConclusionThis study demonstrated a very good sensitivity and specificity of POCUS for intussusception in children when performed by multiple emergency physicians with varying POCUS experience.
Outcomes of surgical site infections following spinal column trauma
Authors: Baroun‐Agob Louay , Liew Susan , Gabbe Belinda 
Published: February 2021

AbstractBackgroundSurgical site infections (SSI) are an undesirable outcome of spinal surgery for both the patient and healthcare system. To date, few studies have investigated the impact of SSI on patient‐reported and clinical outcomes. Sepsis and readmission are potential sequelae of SSI, with sepsis potentially being life threatening. This study aimed to assess the association between SSI and patient outcomes in a spinal trauma cohort.MethodsAdult (16+ years) patients who underwent emergency spinal surgery due to trauma between January 2010 and December 2016 at a major trauma centre in Melbourne, Australia, were identified through the Victorian Orthopaedic Trauma Outcomes Registry. The presence of an SSI was abstracted from the electronic medical record and outcomes were compared between patients with and without an SSI. Clinical outcomes were obtained from the medical record, and patient‐reported outcomes at 6 and 12 months were obtained from the Victorian Orthopaedic Trauma Outcomes Registry. Chi‐squared tests were used to compare patient outcomes between groups.ResultsOf the 458 included patients, 26 (5.7%) developed an SSI. Patient‐reported outcomes at 6 and 12 months were not different between the groups. An SSI was associated with sepsis (χ21 = 24.20, P < 0.01), readmission (χ21 = 215.34, P < 0.01), revision surgery (χ21 = 171.21, P < 0.01) and removal of implants (χ21 = 4.31, P = 0.04) within 12 months of discharge.ConclusionThese findings indicate that spine trauma SSIs are not associated with patient‐reported outcomes and may not have lasting effects on patients. Larger studies are required to assess further follow‐up and support our findings and possibly distinguish outcomes between superficial and deep SSI.
A bi‐centric experience of extracorporeal carbon dioxide removal (ECCO2R) for acute hypercapnic respiratory failure following allogeneic hematopoietic stem cell transplantation
Authors: Wohlfarth Philipp , Schellongowski Peter , Staudinger Thomas , Rabitsch Werner , Hermann Alexander , Buchtele Nina , Turki Amin T. , Tzalavras Asterios , Liebregts Tobias 
Published: February 2021

AbstractAcute respiratory failure (ARF) is the main reason for ICU admission following allogeneic hematopoietic stem cell transplantation (HSCT). Extracorporeal CO2 removal (ECCO2R) can be used as an adjunct to mechanical ventilation in patients with severe hypercapnia but has not been assessed in HSCT recipients. Retrospective analysis of all allogeneic HSCT recipients ≥18 years treated with ECCO2R at two HSCT centers. 11 patients (m:f = 4:7, median age: 45 [IQR: 32‐58] years) were analyzed. Acute leukemia was the underlying hematologic malignancy in all patients. The time from HSCT to ICU admission was 37 [8‐79] months, and 9/11 (82%) suffered from chronic graft‐versus‐host disease (GVHD) with lung involvement. Pneumonia was the most frequent reason for ventilatory decompensation (n = 9). ECCO2R was initiated for severe hypercapnia (PaCO2: 96 [84‐115] mm Hg; pH: 7.13 [7.09‐7.27]) despite aggressive mechanical ventilation (invasive, n = 9; non‐invasive, n = 2). ECCO2R effectively resolved blood gas disturbances in all patients, but only 2/11 (18%) could be weaned off ventilatory support, and one (9%) patient survived hospital discharge. Progressive respiratory and multiorgan dysfunction were the main reasons for treatment failure. ECCO2R was technically feasible but resulted in a low survival rate in our cohort. A better understanding of the prognosis of ARF in patients with chronic GVHD and lung involvement is necessary before its use can be reconsidered in this setting.
Effect of age on reoperation rate in children undergoing exotropia surgery
Authors: Heo Hwan , Lambert Scott R. 
Published: February 2021

AbstractPurposeTo determine the effect of age on the reoperation rate in children undergoing exotropia surgery.MethodsThis was a population‐based retrospective cohort study using claims data that included children ≤ 12 years who had undergone exotropia surgery as the first strabismus operation and had ≥ 3 years of continuous enrolment were selected from the Optum de‐identified Clinformatics Data Mart Database (2003–2019). Patient age at the first exotropia surgery was grouped into three categories; 0–3, 4–6, and 7–12 years. We assessed the sex, race, age, surgical methods, continuous enrolment period after the first surgery, and the time between the first surgery and reoperation. Cox regression analysis was used to estimate the risk of reoperation at different ages. The hazard ratio of reoperation in children undergoing exotropia surgery according to the age at the first exotropia surgery.ResultsAmong 2015 children, 312 (15.5%) underwent one or more reoperations. A reoperation was more often performed for recurrent exotropia (n = 231) than for consecutive esotropia (n = 81). The time between the first surgery and reoperation was shorter for reoperation for consecutive esotropia (376 days) than for recurrent exotropia (672 days) (p < 0.001). Younger children showed a higher reoperation hazard ratio than older children (p < 0.001). In reoperation for consecutive esotropia, the patients aged 0–3 years showed a high hazard ratio (2.82; 95% CI, 1.59–5.01).ConclusionChildren undergoing exotropia surgery at a younger age have a higher reoperation rate than those undergoing surgery at an older age.
Impact of anticoagulant exposure misclassification on the bleeding risk of direct oral anticoagulants
Authors: Hempenius Mirjam , Groenwold Rolf H. H. , Souverein Patrick C. , de Boer Anthonius , Klungel Olaf H. , Gardarsdottir Helga 
Published: February 2021

AimsDrug exposure status based on routinely collected data might be misclassified when the database contains only prescriptions from 1 type of prescriber (e.g. general practitioner and not specialist). This study aims to quantify the impact of such exposure misclassification on the risk of major bleeding and stroke/transient ischaemic attack (TIA)associated with direct oral anticoagulants (DOACs) vs. vitamin K antagonists (VKAs).MethodsIncident anticoagulant users (>12 mo free of anticoagulation use) in the Dutch PHARMO Database Network between 2008 and 2017 were included. Drug exposure was assessed using pharmacy dispensing information. The risks of hospital admission of major bleeding for DOAC vs. VKA users was assessed with Cox regression analysis, where exposure was based on all dispensings, on general practitioner (GP)‐prescribed dispensings only or on specialist‐prescribed dispensings only. Hazard ratios (HRs) were estimated also for hospitalization for gastrointestinal bleeding, intracranial bleeding and stroke/TIA.ResultsWe included 99 182 VKA‐initiators and 21 795 DOAC‐initiators. Use of DOAC was associated with a lower risk of major bleeding compared to VKA use; HR 0.79 (95% confidence interval 0.70–0.90), 0.78 (0.68–0.91) and 0.62 (0.50–0.76), for exposure based on complete dispensing information, only GP‐ and only specialist‐prescribed dispensings, respectively. Similar results were found for the other bleeding outcomes. For stroke/TIA the HRs were 0.96 (0.84–1.09), 1.00 (0.84–1.18) and 0.72 (0.58–0.90), respectively.ConclusionIncluding only GP‐prescribed anticoagulant dispensings in this case did not materially impact the effect estimates compared to including all anticoagulant dispensings. Including only specialist‐prescribed dispensings, however, strengthened the effect estimates.
Causal interaction trees: Finding subgroups with heterogeneous treatment effects in observational data
Authors: Yang Jiabei , Dahabreh Issa J. , Steingrimsson Jon A. 
Published: February 2021

AbstractWe introduce causal interaction tree (CIT) algorithms for finding subgroups of individuals with heterogeneous treatment effects in observational data. The CIT algorithms are extensions of the classification and regression tree algorithm that use splitting criteria based on subgroup‐specific treatment effect estimators appropriate for observational data. We describe inverse probability weighting, g‐formula, and doubly robust estimators of subgroup‐specific treatment effects, derive their asymptotic properties, and use them to construct splitting criteria for the CIT algorithms. We study the performance of the algorithms in simulations and implement them to analyze data from an observational study that evaluated the effectiveness of right heart catheterization for critically ill patients.
Bayesian dose regimen assessment in early phase oncology incorporating pharmacokinetics and pharmacodynamics
Authors: Gerard Emma , Zohar Sarah , Thai Hoai‐Thu , Lorenzato Christelle , Riviere Marie‐Karelle , Ursino Moreno 
Published: February 2021

AbstractPhase I dose‐finding trials in oncology seek to find the maximum tolerated dose of a drug under a specific schedule. Evaluating drug schedules aims at improving treatment safety while maintaining efficacy. However, while we can reasonably assume that toxicity increases with the dose for cytotoxic drugs, the relationship between toxicity and multiple schedules remains elusive. We proposed a Bayesian dose regimen assessment method (DRtox) using pharmacokinetics/pharmacodynamics (PK/PD) to estimate the maximum tolerated dose regimen (MTD‐regimen) at the end of the dose‐escalation stage of a trial. We modeled the binary toxicity via a PD endpoint and estimated the dose regimen toxicity relationship through the integration of a dose regimen PD model and a PD toxicity model. For the first model, we considered nonlinear mixed‐effects models, and for the second one, we proposed the following two Bayesian approaches: a logistic model and a hierarchical model. In an extensive simulation study, the DRtox outperformed traditional designs in terms of proportion of correctly selecting the MTD‐regimen. Moreover, the inclusion of PK/PD information helped provide more precise estimates for the entire dose regimen toxicity curve; therefore the DRtox may recommend alternative untested regimens for expansion cohorts. The DRtox was developed to be applied at the end of the dose‐escalation stage of an ongoing trial for patients with relapsed or refractory acute myeloid leukemia (NCT03594955) once all toxicity and PK/PD data are collected.
Bayesian data fusion: Probabilistic sensitivity analysis for unmeasured confounding using informative priors based on secondary data
Authors: Comment Leah , Coull Brent A. , Zigler Corwin , Valeri Linda 
Published: February 2021

AbstractBayesian causal inference offers a principled approach to policy evaluation of proposed interventions on mediators or time‐varying exposures. Building on the Bayesian g‐formula method introduced by Keil et al., we outline a general approach for the estimation of population‐level causal quantities involving dynamic and stochastic treatment regimes, including regimes related to mediation estimands such as natural direct and indirect effects. We further extend this approach to propose a Bayesian data fusion (BDF), an algorithm for performing probabilistic sensitivity analysis when a confounder unmeasured in a primary data set is available in an external data source. When the relevant relationships are causally transportable between the two source populations, BDF corrects confounding bias and supports causal inference and decision‐making within the main study population without sharing of the individual‐level external data set. We present results from a simulation study comparing BDF to two common frequentist correction methods for unmeasured mediator‐outcome confounding bias in the mediation setting. We use these methods to analyze data on the role of stage at cancer diagnosis in contributing to Black–White colorectal cancer survival disparities.
Talking with parents of children with learning disabilities: Parents’ ideas about the Circle of Security parenting programme
Authors: Muddle Sarah , McElwee Jennifer , Vincent Regine , Birdsey Nicola , Best Lara 
Published: February 2021

Accessible Summary

The Circle of Security Parenting (COS‐P) programme can be helpful for some parents of children with learning disabilities to think about their relationship with their child.

Parenting a child with learning disabilities is different, and COS‐P can highlight this difference.

This can feel painful for parents and may stop them engaging with the programme.

AbstractBackgroundBackground: The promotion of secure attachment relationships in childhood leads to better outcomes in later life (British Psychological Society 2017, Incorporating Attachment Theory into Practice: Clinical Practice Guideline for Clinical Psychologists Working with People who have Intellectual Disabilities). The Circle of Security Parenting Programme (COS‐P) provides a clear framework for reflecting on attachment relationships (Cooper et al 2009, Zero to Three, 37, 27).MethodsMethods: Semi‐structured interviews were conducted with parents of children with learning disabilities who attended a COS‐P programme to find out about their experiences of the course and how applicable it was to them. The data were analysed using thematic analysis.FindingsFindings: Four key themes were identified: these related to (1) COS‐P concepts are relevant to all children but (2) parenting a child with a learning disability is different and (3) COS‐P can create a focus on their child as different, which can be painful, and (4) changes recommended to make COS‐P suitable for parents of children with learning disabilities.ConclusionsConclusions: This paper outlines the benefits and challenges of COS‐P in sharing concepts related to attachment, whilst highlighting differences for parents of children and young people with learning disabilities, which can be painful.
The functional ecology of bat pollination in the African sausage tree Kigelia africana (Bignoniaceae)
Authors: Newman Ethan , Govender Keeveshnee , van Niekerk Sandy , Johnson Steven D. 
Published: February 2021

AbstractPlants often interact with a wide range of animal floral visitors that can vary in their pollination effectiveness. Flowers of the African sausage tree Kigelia africana are visited by bats and bush babies during the night and by birds during the day. We studied floral traits (phenophases, scent, color, and nectar chemistry) and the visitation frequency and pollination effectiveness of different flower visitors to determine whether K. africana is functionally specialized for bat pollination. We found that flower opening corresponds with bat activity, flowers emit scent dominated by aliphatic esters and alcohols, and that nectar is produced in copious amounts accessible to bats. Pollen deposition on stigmas was twenty‐fold greater per visit by bats than it was per visit by birds, likely a result of the close morphological fit between snouts of bats and the flowers. However, bat visits appear to be rare at some sites and the delayed senescence of flowers that are open throughout the morning provides an opportunity for additional pollination by birds. We conclude that K. africana is primarily adapted for bat pollination, but is also able to exploit other animals for pollination.