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1.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34934011

RESUMO

Content on Twitter's home timeline is selected and ordered by personalization algorithms. By consistently ranking certain content higher, these algorithms may amplify some messages while reducing the visibility of others. There's been intense public and scholarly debate about the possibility that some political groups benefit more from algorithmic amplification than others. We provide quantitative evidence from a long-running, massive-scale randomized experiment on the Twitter platform that committed a randomized control group including nearly 2 million daily active accounts to a reverse-chronological content feed free of algorithmic personalization. We present two sets of findings. First, we studied tweets by elected legislators from major political parties in seven countries. Our results reveal a remarkably consistent trend: In six out of seven countries studied, the mainstream political right enjoys higher algorithmic amplification than the mainstream political left. Consistent with this overall trend, our second set of findings studying the US media landscape revealed that algorithmic amplification favors right-leaning news sources. We further looked at whether algorithms amplify far-left and far-right political groups more than moderate ones; contrary to prevailing public belief, we did not find evidence to support this hypothesis. We hope our findings will contribute to an evidence-based debate on the role personalization algorithms play in shaping political content consumption.

2.
N Engl J Med ; 382(26): 2514-2523, 2020 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-32579812

RESUMO

BACKGROUND: The effects on patient safety of eliminating extended-duration work shifts for resident physicians remain controversial. METHODS: We conducted a multicenter, cluster-randomized, crossover trial comparing two schedules for pediatric resident physicians during their intensive care unit (ICU) rotations: extended-duration work schedules that included shifts of 24 hours or more (control schedules) and schedules that eliminated extended shifts and cycled resident physicians through day and night shifts of 16 hours or less (intervention schedules). The primary outcome was serious medical errors made by resident physicians, assessed by intensive surveillance, including direct observation and chart review. RESULTS: The characteristics of ICU patients during the two work schedules were similar, but resident physician workload, described as the mean (±SD) number of ICU patients per resident physician, was higher during the intervention schedules than during the control schedules (8.8±2.8 vs. 6.7±2.2). Resident physicians made more serious errors during the intervention schedules than during the control schedules (97.1 vs. 79.0 per 1000 patient-days; relative risk, 1.53; 95% confidence interval [CI], 1.37 to 1.72; P<0.001). The number of serious errors unitwide were likewise higher during the intervention schedules (181.3 vs. 131.5 per 1000 patient-days; relative risk, 1.56; 95% CI, 1.43 to 1.71). There was wide variability among sites, however; errors were lower during intervention schedules than during control schedules at one site, rates were similar during the two schedules at two sites, and rates were higher during intervention schedules than during control schedules at three sites. In a secondary analysis that was adjusted for the number of patients per resident physician as a potential confounder, intervention schedules were no longer associated with an increase in errors. CONCLUSIONS: Contrary to our hypothesis, resident physicians who were randomly assigned to schedules that eliminated extended shifts made more serious errors than resident physicians assigned to schedules with extended shifts, although the effect varied by site. The number of ICU patients cared for by each resident physician was higher during schedules that eliminated extended shifts. (Funded by the National Heart, Lung, and Blood Institute; ROSTERS ClinicalTrials.gov number, NCT02134847.).


Assuntos
Unidades de Terapia Intensiva Pediátrica/organização & administração , Internato e Residência/organização & administração , Erros Médicos/estatística & dados numéricos , Segurança do Paciente , Admissão e Escalonamento de Pessoal , Tolerância ao Trabalho Programado , Carga de Trabalho , Estudos Cross-Over , Humanos , Erros Médicos/prevenção & controle , Desempenho Psicomotor/fisiologia , Sono , Fatores de Tempo
3.
BMC Infect Dis ; 23(1): 804, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37974068

RESUMO

BACKGROUND: Defining patterns of symptoms in long COVID is necessary to advance therapies for this heterogeneous condition. Here we aimed to describe clusters of symptoms in individuals with long COVID and explore the impact of the emergence of variants of concern (VOCs) and vaccination on these clusters. METHODS: In a prospective, multi centre cohort study, individuals with symptoms persisting > 4 weeks from acute COVID-19 were divided into two groups based on timing of acute infection; pre-Alpha VOC, denoted wild type (WT) group and post-Alpha VOC (incorporating alpha and delta dominant periods) denoted VOC group. We used multiple correspondence analysis (MCA) and hierarchical clustering in the WT and VOC groups to identify symptom clusters. We then used logistic regression to explore factors associated with individual symptoms. RESULTS: A total of 417 individuals were included in the analysis, 268 in WT and 149 in VOC groups respectively. In both groups MCA identified three similar clusters; a musculoskeletal (MSK) cluster characterised by joint pain and myalgia, a cardiorespiratory cluster and a less symptomatic cluster. Differences in characteristic symptoms were only seen in the cardiorespiratory cluster where a decrease in the frequency of palpitations (10% vs 34% p = 0.008) and an increase in cough (63% vs 17% p < 0.001) in the VOC compared to WT groups was observed. Analysis of the frequency of individual symptoms showed significantly lower frequency of both chest pain (25% vs 39% p = 0.004) and palpitations (12% vs 32% p < 0.001) in the VOC group compared to the WT group. In adjusted analysis being in the VOC group was significantly associated with a lower odds of both chest pain and palpitations, but vaccination was not associated with these symptoms. CONCLUSION: This study suggests changes in long COVID phenotype in individuals infected later in the pandemic, with less palpitations and chest pain reported. Adjusted analyses suggest that these effects are mediated through introduction of variants rather than an effect from vaccination.


Assuntos
COVID-19 , Síndrome de COVID-19 Pós-Aguda , Humanos , COVID-19/prevenção & controle , Estudos de Coortes , Estudos Prospectivos , Vacinação , Dor no Peito , Fenótipo
4.
Telemed J E Health ; 28(7): 1064-1069, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34898259

RESUMO

Introduction: Testing facilities for COVID-19 were stood up around the country during the pandemic, but could not handle the demand. This study aimed to combine a mobile application (App) with an at-home test kit to facilitate home-based testing. Methods: After integrating an App with an at-home testing service, we measured the time between sample collection and notification of results. We recruited 92 volunteers to utilize the platform. Results: Sixty-one percent (55/92) responded to the survey. Median sample collection-to-result time was 2.2 days (IQR = 1.3-3.2). Eighty-two percent (45/55) found the self-test kit and App easy to use. Eighty-four percent agreed that the combined solution is an acceptable way to receive health care services. Discussion: Decreasing testing time and providing timely test results improve care access and decrease the risk of infection. Combining a tailored App with an at-home testing service is a feasible solution to reaching that goal.


Assuntos
COVID-19 , Aplicativos Móveis , COVID-19/epidemiologia , Humanos , Pandemias , Inquéritos e Questionários
5.
Mol Biol Evol ; 37(7): 2002-2014, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32191319

RESUMO

Sensory systems are tuned by selection to maximize organismal fitness in particular environments. This tuning has implications for intraspecies communication, the maintenance of species boundaries, and speciation. Tuning of color vision largely depends on the sequence of the expressed opsin proteins. To improve tuning of visual sensitivities to shifts in habitat or foraging ecology over the course of development, many organisms change which opsins are expressed. Changes in this developmental sequence (heterochronic shifts) can create differences in visual sensitivity among closely related species. The genetic mechanisms by which these developmental shifts occur are poorly understood. Here, we use quantitative trait locus analyses, genome sequencing, and gene expression studies in African cichlid fishes to identify a role for the transcription factor Tbx2a in driving a switch between long wavelength sensitive (LWS) and Rhodopsin-like (RH2) opsin expression. We identify binding sites for Tbx2a in the LWS promoter and the highly conserved locus control region of RH2 which concurrently promote LWS expression while repressing RH2 expression. We also present evidence that a single change in Tbx2a regulatory sequence has led to a species difference in visual tuning, providing the first mechanistic model for the evolution of rapid switches in sensory tuning. This difference in visual tuning likely has important roles in evolution as it corresponds to differences in diet, microhabitat choice, and male nuptial coloration.


Assuntos
Ciclídeos/metabolismo , Evolução Molecular , Opsinas/metabolismo , Proteínas com Domínio T/metabolismo , Animais , Células HEK293 , Humanos , Locos de Características Quantitativas
6.
Metab Eng ; 66: 31-40, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33813033

RESUMO

In cell culture processes cell growth and metabolism drive changes in the chemical environment of the culture. These environmental changes elicit reactor control actions, cell growth response, and are sensed by cell signaling pathways that influence metabolism. The interplay of these forces shapes the culture dynamics through different stages of cell cultivation and the outcome greatly affects process productivity, product quality, and robustness. Developing a systems model that describes the interactions of those major players in the cell culture system can lead to better process understanding and enhance process robustness. Here we report the construction of a hybrid mechanistic-empirical bioprocess model which integrates a mechanistic metabolic model with subcomponent models for cell growth, signaling regulation, and the bioreactor environment for in silico exploration of process scenarios. Model parameters were optimized by fitting to a dataset of cell culture manufacturing process which exhibits variability in metabolism and productivity. The model fitting process was broken into multiple steps to mitigate the substantial numerical challenges related to the first-principles model components. The optimized model captured the dynamics of metabolism and the variability of the process runs with different kinetic profiles and productivity. The variability of the process was attributed in part to the metabolic state of cell inoculum. The model was then used to identify potential mitigation strategies to reduce process variability by altering the initial process conditions as well as to explore the effect of changing CO2 removal capacity in different bioreactor scales on process performance. By incorporating a mechanistic model of cell metabolism and appropriately fitting it to a large dataset, the hybrid model can describe the different metabolic phases in culture and the variability in manufacturing runs. This approach of employing a hybrid model has the potential to greatly facilitate process development and reactor scaling.


Assuntos
Reatores Biológicos , Técnicas de Cultura de Células , Animais , Simulação por Computador , Cinética , Transdução de Sinais
7.
Metab Eng ; 56: 154-164, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31400493

RESUMO

Pathway engineering is a powerful tool in biotechnological and clinical applications. However, many phenomena cannot be rewired with a single enzyme change, and in a complex network like energy metabolism, the selection of combinations of targets to engineer is a daunting task. To facilitate this process, we have developed an optimization framework and applied it to a mechanistic kinetic model of energy metabolism. We then identified combinations of enzyme alternations that led to the elimination of the Warburg effect seen in the metabolism of cancer cells and cell lines, a phenomenon coupling rapid proliferation to lactate production. Typically, optimization approaches use integer variables to achieve the desired flux redistribution with a minimum number of altered genes. This framework uses convex penalty terms to replace these integer variables and improve computational tractability. Optimal solutions are identified which substantially reduce or eliminate lactate production while maintaining the requirements for cellular proliferation using three or more enzymes.


Assuntos
Glicólise , Ácido Láctico/metabolismo , Modelos Biológicos , Neoplasias/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias/patologia
8.
Biotechnol Bioeng ; 116(6): 1341-1354, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30739313

RESUMO

Mucin-type O-glycans have profound effects on the structure and stability of glycoproteins. O-Glycans on the cell surface proteins also modulate the cell's interactions with the surrounding environments and other cells. The synthetic pathway of O-glycans involves a large number of enzymes with diverse substrate specificity. The expression pattern of these enzymes is cell and tissue-specific, thus making the pathway highly diverse. To facilitate pathway analysis in a cell and tissue-specific fashion, we developed an integrated platform of RING (Rule Input Network Generator) and O-GlycoVis. RING uses an English-like reaction language to describe the substrate specificity of enzymes and additional constraints on the formation of the glycan products. Using this information, the RING generates a list of possible glycans, which is used as input into O-Glycovis. O-GlycoVis displays the glycan distribution in the pathway and potential reaction paths leading to each glycan. With the input glycan data, O-GlycoVis also traces all possible reaction paths leading to each glycan and outputs pathway maps with the relative abundance levels of glycans overlaid. O-Glycan profiles from two breast cancer cell lines, MCF7 and T47d, human umbilical vascular endothelium cells, Chinese Hamster Ovary cells were generated based on transcriptional data and compared with experimentally observed O-glycans. This RING-based program allows rules to be added or subtracted for network generation and visualization of networks of O-glycosylation network of different tissues and species.


Assuntos
Vias Biossintéticas , Polissacarídeos/metabolismo , Animais , Biocatálise , Neoplasias da Mama/metabolismo , Células CHO , Cricetulus , Feminino , Glicosilação , Células Endoteliais da Veia Umbilical Humana , Humanos , Células MCF-7 , Software , Especificidade por Substrato
9.
J Sleep Res ; 28(6): e12869, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31131535

RESUMO

This study investigated whether sleep disorder risk and mental health outcomes in firefighters were associated with burnout, particularly emotional exhaustion, and examined the mediating role of sleep at work in these relationships. A secondary aim was to investigate associations between habitual sleep characteristics and burnout. North American firefighters (n = 6,307) completed the Maslach Burnout Inventory (emotional exhaustion, depersonalisation, personal accomplishment), and were screened for sleep disorders and self-reported current mental health conditions and sleep characteristics. Multiple logistic regression analyses examined associations between sleep, mental health outcomes and burnout. Firefighters screening positive for a sleep disorder, particularly insomnia, had increased risk of emotional exhaustion (adjusted odds ratio 3.78, 95% confidence interval 2.97-4.79). Firefighters self-reporting a current mental health condition were at greater risk of emotional exhaustion (adjusted odds ratio 3.45, 95% confidence interval 2.79-4.27). Sleep during overnight work mediated the impact of having a sleep disorder and mental health condition on high burnout. Sleepiness and sleep deficit (difference between required and actual sleep), even in firefighters without sleep disorder risk, were associated with depersonalisation (adjusted odds ratio 1.65, 95% confidence interval 1.34-2.03 and adjusted odds ratio 1.29, 95% confidence interval 1.06-1.57, respectively) and low personal accomplishment (adjusted odds ratio 1.25, 95% confidence interval 1.07-1.47 and adjusted odds ratio 1.17, 95% confidence interval 1.01-1.35, respectively). Sleep and mental health problems were associated with increased risk of burnout in firefighters, and sleep during overnight work mediated these relationships. The results suggest the need to examine the effectiveness of occupational interventions that improve the opportunity for sleep, together with screening for and treating sleep disorders, to reduce burnout risk.


Assuntos
Bombeiros/psicologia , Saúde Mental/tendências , Transtornos do Sono-Vigília/complicações , Transtornos do Sono-Vigília/psicologia , Tolerância ao Trabalho Programado/psicologia , Adulto , Esgotamento Profissional/psicologia , Estudos Transversais , Feminino , Humanos , Masculino , Autorrelato
10.
Proc Natl Acad Sci U S A ; 113(1): 176-81, 2016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26699470

RESUMO

Night-shift workers are at high risk of drowsiness-related motor vehicle crashes as a result of circadian disruption and sleep restriction. However, the impact of actual night-shift work on measures of drowsiness and driving performance while operating a real motor vehicle remains unknown. Sixteen night-shift workers completed two 2-h daytime driving sessions on a closed driving track at the Liberty Mutual Research Institute for Safety: (i) a postsleep baseline driving session after an average of 7.6 ± 2.4 h sleep the previous night with no night-shift work, and (ii) a postnight-shift driving session following night-shift work. Physiological measures of drowsiness were collected, including infrared reflectance oculography, electroencephalography, and electrooculography. Driving performance measures included lane excursions, near-crash events, and drives terminated because of failure to maintain control of the vehicle. Eleven near-crashes occurred in 6 of 16 postnight-shift drives (37.5%), and 7 of 16 postnight-shift drives (43.8%) were terminated early for safety reasons, compared with zero near-crashes or early drive terminations during 16 postsleep drives (Fishers exact: P = 0.0088 and P = 0.0034, respectively). Participants had a significantly higher rate of lane excursions, average Johns Drowsiness Scale, blink duration, and number of slow eye movements during postnight-shift drives compared with postsleep drives (3.09/min vs. 1.49/min; 1.71 vs. 0.97; 125 ms vs. 100 ms; 35.8 vs. 19.1; respectively, P < 0.05 for all). Night-shift work increases driver drowsiness, degrading driving performance and increasing the risk of near-crash drive events. With more than 9.5 million Americans working overnight or rotating shifts and one-third of United States commutes exceeding 30 min, these results have implications for traffic and occupational safety.


Assuntos
Acidentes de Trânsito , Condução de Veículo/psicologia , Transtornos do Sono do Ritmo Circadiano/fisiopatologia , Fases do Sono/fisiologia , Adulto , Piscadela/fisiologia , Eletroencefalografia , Eletroculografia , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos
11.
J Sleep Res ; 27(6): e12722, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30069960

RESUMO

The objective of the study was to determine if sleep disorder, depression or anxiety screening status was associated with safety outcomes in a diverse population of hospital workers. A sample of shift workers at four hospitals participated in a prospective cohort study. Participants were screened for five sleep disorders, depression and anxiety at baseline, then completed prospective monthly surveys for the next 6 months to capture motor vehicle crashes, near-miss crashes, occupational exposures and medical errors. We tested the associations between sleep disorders, depression and anxiety and adverse safety outcomes using incidence rate ratios adjusted for potentially confounding factors in a multivariable negative binomial regression model. Of the 416 hospital workers who participated, two in five (40.9%) screened positive for a sleep disorder and 21.6% screened positive for depression or anxiety. After multivariable adjustment, screening positive for a sleep disorder was associated with 83% increased incidence of adverse safety outcomes. Screening positive for depression or anxiety increased the risk by 63%. Sleep disorders and mood disorders were independently associated with adverse outcomes and contributed additively to risk. Our findings suggest that screening for sleep disorders and mental health screening can help identify individuals who are vulnerable to adverse safety outcomes. Future research should evaluate sleep and mental health screening, evaluation and treatment programmes that may improve safety.


Assuntos
Ansiedade/epidemiologia , Depressão/epidemiologia , Pessoal de Saúde/normas , Jornada de Trabalho em Turnos/efeitos adversos , Transtornos do Sono-Vigília/epidemiologia , Acidentes de Trânsito/prevenção & controle , Acidentes de Trânsito/psicologia , Adulto , Ansiedade/diagnóstico , Ansiedade/psicologia , Estudos de Coortes , Depressão/diagnóstico , Depressão/psicologia , Feminino , Pessoal de Saúde/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Jornada de Trabalho em Turnos/psicologia , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/psicologia , Inquéritos e Questionários
12.
Mol Biol Evol ; 31(9): 2297-308, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24859246

RESUMO

The mechanisms underlying natural phenotypic diversity are key to understanding evolution and speciation. Cichlid fishes are among the most speciose vertebrates and an ideal model for identifying genes controlling species differences. Cichlids have diverse visual sensitivities that result from species expressing subsets of seven cichlid cone opsin genes. We previously identified a quantitative trait locus (QTL) that tunes visual sensitivity by varying SWS2A (short wavelength sensitive 2A) opsin expression in a genetic cross between two Lake Malawi cichlid species. Here, we identify Rx1 (retinal and anterior neural fold homeobox) as the causative gene for the QTL using fine mapping and RNAseq in retinal transcriptomes. Rx1 is differentially expressed between the parental species and correlated with SWS2A expression in the F2 progeny. Expression of Rx1 and SWS2A is also correlated in a panel of 16 Lake Malawi cichlid species. Association mapping in this panel identified a 413-bp deletion located 2.5-kb upstream of the Rx1 translation start site that is correlated with decreased Rx1 expression. This deletion explains 62% of the variance in SWS2A expression across 53 cichlid species in 29 genera. The deletion occurs in both the sand and rock-dwelling cichlid clades, suggesting that it is an ancestral polymorphism. Our finding supports the hypothesis that mixing and matching of ancestral polymorphisms can explain the diversity of present day cichlid phenotypes.


Assuntos
Ciclídeos/genética , Opsinas dos Cones/genética , Proteínas do Olho/genética , Proteínas de Peixes/genética , Retina/metabolismo , Animais , Sequência de Bases , Ciclídeos/classificação , Ciclídeos/metabolismo , Evolução Molecular , Regulação da Expressão Gênica , Variação Genética , Genômica/métodos , Fenótipo , Filogenia , Locos de Características Quantitativas , Análise de Sequência de RNA , Deleção de Sequência , Especificidade da Espécie
13.
EClinicalMedicine ; 72: 102641, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38840669

RESUMO

Workplace violence (WPV) against healthcare workers (HCW) is a globally growing problem in healthcare systems. Despite decades of research and interventions violent incidents are rising in their severity and frequency. A structured review of PubMed and Scopus databases and supplementary internet searches, resulted in a synthesis of evidence covering multiple countries and healthcare worker populations. High rates of WPV are increasingly common due to unmet patient expectations, poor communication, long wait times and organizational factors such as resourcing and infrastructure. We highlight links between WPV and poor worker health outcomes, staff turnover, reduced patient safety and medical errors. Few prevention and mitigation activities have shown sustained effects, highlighting the challenges in understanding and addressing the complex interplay of factors that drive violence against HCWs. The rapidly rising incidence of WPV requires special consideration and action from multiple stakeholders including patients and visitors, healthcare providers, law enforcement, media and policy makers.

14.
Ir J Med Sci ; 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38478182

RESUMO

BACKGROUND: Remediation of underperforming students is recognised as an important tool in medical education; however, there is no universally agreed approach. AIMS: This study aimed to evaluate the effectiveness of a remediation program for final year medical students who failed their first long case assessment (LCA1) and to compare their academic performance with their peers who passed their first long case assessment. METHODS: The study consisted of two phases. Phase 1 analysed the demographics and academic performance data for the 9% of the class in the remediation group. Phase 2 focused on collecting similar data for the remaining 91% of students in the non-remediation group. Statistical analyses including the Wilcoxon rank sum test and Pearson correlation coefficients were used to compare the groups. RESULTS: Phase 1 showed 88% of students who participated in remediation successfully passed the second long case assessment (LCA2); however, 25% of this cohort ultimately failed the academic year due to poor results in other assessments. Phase 2 results revealed that non-remediation group students scored significantly higher in LCA2 (59.71% vs 52.07%, p < 0.001) compared to their remediation counterparts, despite 19% of them failing this assessment. Non-remediation group students consistently outperformed their remediation group counterparts in formative and summative assessments. Overall, 6.25% of the entire class failed the academic year. CONCLUSION: This study demonstrates the need to focus on overall academic performance to identify struggling students rather than one high stakes exam. Most of the students in the remediation programme ultimately passed LCA2.

15.
Sleep Health ; 10(1S): S25-S33, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38007304

RESUMO

OBJECTIVES: Mathematical models of human neurobehavioral performance that include the effects of acute and chronic sleep restriction can be key tools in assessment and comparison of work schedules, allowing quantitative predictions of performance when empirical assessment is impractical. METHODS: Using such a model, we tested the hypothesis that resident physicians working an extended duration work roster, including 24-28 hours of continuous duty and up to 88 hours per week averaged over 4weeks, would have worse predicted performance than resident physicians working a rapidly cycling work roster intervention designed to reduce the duration of extended shifts. The performance metric used was attentional failures (ie, Psychomotor Vigilance Task lapses). Model input was 169 actual work and sleep schedules. Outcomes were predicted hours per week during work hours spent at moderate (equivalent to 16-20 hours of continuous wakefulness) or high (equivalent to ≥20 hours of continuous wakefulness) performance impairment. RESULTS: The model predicted that resident physicians working an extended duration work roster would spend significantly more time at moderate impairment (p = .02, effect size=0.2) than those working a rapidly cycling work roster; this difference was most pronounced during the circadian night (p < .001). On both schedules, performance was predicted to decline from weeks 1 + 2 to weeks 3 + 4 (p < .001), but the rate of decline was significantly greater on extended duration work roster (p < .01). Predicted performance impairment was inversely related to prior sleep duration (p < .001). CONCLUSIONS: These findings demonstrate the utility of a mathematical model to evaluate the predicted performance profile of schedules for resident physicians and others who experience chronic sleep restriction and circadian misalignment.

16.
Mol Ecol ; 22(11): 2864-83, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23718143

RESUMO

Understanding how genetic variation is partitioned across genomes within and among populations is a fundamental problem in ecological and evolutionary genetics. To address this problem, we studied the threespine stickleback fish, which has repeatedly undergone parallel phenotypic and genetic differentiation when oceanic fish have invaded freshwater habitats. While significant evolutionary genetic research has been performed using stickleback from geographic regions that have been deglaciated in the last 20 000 years, less research has focused on freshwater populations that predate the last glacial maximum. We performed restriction-site associated DNA-sequencing (RAD-seq) based population genomic analyses on stickleback from across Oregon, which was not glaciated during the last maximum. We sampled stickleback from coastal, Willamette Basin and central Oregon sites, analysed their genetic diversity using RAD-seq, performed structure analyses, reconstructed their phylogeographic history and tested the hypothesis of recent stickleback introduction into central Oregon, where incidence of this species was only recently documented. Our results showed a clear phylogeographic break between coastal and inland populations, with oceanic populations exhibiting the lowest levels of divergence from one another. Willamette Basin and central Oregon populations formed a clade of closely related populations, a finding consistent with a recent introduction of stickleback into central Oregon. Finally, genome-wide analysis of genetic diversity (π) and correlations of alleles within individuals in subpopulations (FIS) supported a role for introgressive hybridization in coastal populations and a recent expansion in central Oregon. Our results exhibit the power of next-generation sequencing genomic approaches such as RAD-seq to identify both historical population structure and recent colonization history.


Assuntos
Filogeografia , Smegmamorpha/classificação , Smegmamorpha/genética , Animais , Sequência de Bases , Demografia , Evolução Molecular , Água Doce , Variação Genética , Genética Populacional , Sequenciamento de Nucleotídeos em Larga Escala , Camada de Gelo , Oregon , Análise de Sequência de DNA
17.
BMJ Qual Saf ; 32(2): 81-89, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35537821

RESUMO

BACKGROUND: The Accreditation Council for Graduate Medical Education (ACGME) enacted a policy in 2011 that restricted first-year resident physicians in the USA to work no more than 16 consecutive hours. This was rescinded in 2017. METHODS: We conducted a nationwide prospective cohort study of resident physicians for 5 academic years (2002-2007) before and for 3 academic years (2014-2017) after implementation of the 16 hours 2011 ACGME work-hour limit. Our analyses compare trends in resident physician-reported medical errors between the two cohorts to evaluate the impact of this policy change. RESULTS: 14 796 residents provided data describing 78 101 months of direct patient care. After adjustment for potential confounders, the work-hour policy was associated with a 32% reduced risk of resident physician-reported significant medical errors (rate ratio (RR) 0.68; 95% CI 0.64 to 0.72), a 34% reduced risk of reported preventable adverse events (RR 0.66; 95% CI 0.59 to 0.74) and a 63% reduced risk of reported medical errors resulting in patient death (RR 0.37; 95% CI 0.28 to 0.49). CONCLUSIONS: These findings have broad relevance for those who work in and receive care from academic hospitals in the USA. The decision to lift this work hour policy in 2017 may expose patients to preventable harm.


Assuntos
Internato e Residência , Médicos , Humanos , Admissão e Escalonamento de Pessoal , Carga de Trabalho , Tolerância ao Trabalho Programado , Estudos Prospectivos , Segurança do Paciente , Educação de Pós-Graduação em Medicina , Acreditação
18.
Sleep ; 46(11)2023 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-37158173

RESUMO

STUDY OBJECTIVES: To examine whether drivers are aware of sleepiness and associated symptoms, and how subjective reports predict driving impairment and physiological drowsiness. METHODS: Sixteen shift workers (19-65 years; 9 women) drove an instrumented vehicle for 2 hours on a closed-loop track after a night of sleep and a night of work. Subjective sleepiness/symptoms were rated every 15 minutes. Severe and moderate driving impairment was defined by emergency brake maneuvers and lane deviations, respectively. Physiological drowsiness was defined by eye closures (Johns drowsiness scores) and EEG-based microsleep events. RESULTS: All subjective ratings increased post night-shift (p < 0.001). No severe drive events occurred without noticeable symptoms beforehand. All subjective sleepiness ratings, and specific symptoms, predicted a severe (emergency brake) driving event occurring in the next 15 minutes (OR: 1.76-2.4, AUC > 0.81, p < 0.009), except "head dropping down". Karolinska Sleepiness Scale (KSS), ocular symptoms, difficulty keeping to center of the road, and nodding off to sleep, were associated with a lane deviation in the next 15 minutes (OR: 1.17-1.24, p<0.029), although accuracy was only "fair" (AUC 0.59-0.65). All sleepiness ratings predicted severe ocular-based drowsiness (OR: 1.30-2.81, p < 0.001), with very good-to-excellent accuracy (AUC > 0.8), while moderate ocular-based drowsiness was predicted with fair-to-good accuracy (AUC > 0.62). KSS, likelihood of falling asleep, ocular symptoms, and "nodding off" predicted microsleep events, with fair-to-good accuracy (AUC 0.65-0.73). CONCLUSIONS: Drivers are aware of sleepiness, and many self-reported sleepiness symptoms predicted subsequent driving impairment/physiological drowsiness. Drivers should self-assess a wide range of sleepiness symptoms and stop driving when these occur to reduce the escalating risk of road crashes due to drowsiness.


Assuntos
Acidentes de Trânsito , Condução de Veículo , Humanos , Feminino , Sonolência , Vigília/fisiologia , Sono
19.
Gen Comp Endocrinol ; 178(1): 19-27, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22504272

RESUMO

Photoperiod, or length of day, has a predictable annual cycle, making it an important cue for the timing of seasonal behavior and development in many organisms. Photoperiod is widely used among temperate and polar animals to regulate the timing of sexual maturation. The proper sensing and interpretation of photoperiod can be tightly tied to an organism's overall fitness. In photoperiodic mammals and birds the thyroid hormone pathway initiates sexual maturation, but the degree to which this pathway is conserved across other vertebrates is not well known. We use the threespine stickleback Gasterosteus aculeatus, as a representative teleost to quantify the photoperiodic response of key genes in the thyroid hormone pathway under controlled laboratory conditions. We find that the photoperiodic responses of the hormones are largely consistent amongst multiple populations, although differences suggest physiological adaptation to various climates. We conclude that the thyroid hormone pathway initiates sexual maturation in response to photoperiod in G. aculeatus, and our results show that more components of this pathway are conserved among mammals, birds, and teleost fish than was previously known. However, additional endocrinology, cell biology and molecular research will be required to define precisely which aspects of the pathway are conserved across vertebrates.


Assuntos
Sistemas Neurossecretores/metabolismo , Fotoperíodo , Animais , Aves , Peixes , Hormônio Liberador de Gonadotropina/metabolismo , Hormônio Luteinizante/metabolismo , Mamíferos , Modelos Biológicos , Transdução de Sinais/fisiologia , Tireotropina/metabolismo , Vertebrados
20.
Oral Surg ; 15(1): 30-35, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34548881

RESUMO

Aim: The impact on physiological parameters and well-being from potential respiratory distress caused by FFP3 masks, particularly during extensive clinical sessions, has been widely speculated during the COVID-19 pandemic. This study aims to investigate the effect of FFP3 mask wear on clinicians' pulse rate and oxygen saturation. Material & Methods: Clinical staff within the Oral Surgery department recorded their oxygen saturation (SpO2) and pulse rate prior to donning an FFP3 mask, prior to doffing FFP3 mask and after doffing FFP3 mask using a finger pulse oximeter for a two-week period in May-June 2020. The duration of wear, the session (AM/PM), the brand of mask and the presence of previous COVID-19 symptoms were also recorded. Results: Twenty-eight data sets were collected from twelve participants (1M:11F). Of the FFP3 masks worn, nineteen (67.86%) were ARCOTM, eight (28.57%) were 3MTM masks and one (3.57%) was 3M+TM. At baseline, the mean SpO2 was 98.39% and the mean pulse rate was 72.11. Prior to mask removal, the mean SpO2 was 97.82% and the mean pulse rate was 70.04. At the end of the session, the mean SpO2 was 98.14% and the mean pulse rate was 69.54. The mean duration of wear was 150.34 min. Data sets were collected evenly across AM (14) and PM (14) sessions. Five participants (17.86%) reported previous COVID-19 symptoms. Conclusion: The data demonstrated a mean reduction of 0.25% in oxygen saturation and 3.56% in pulse rate, following the use of an FFP3 mask. These changes in physiological parameters are not clinically significant and sessional use appears to be safe.

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