Proc Natl Acad Sci U S A
November 2024
Accurate estimation of the dispersal velocity or speed of evolving organisms is no mean feat. In fact, existing probabilistic models in phylogeography or spatial population genetics generally do not provide an adequate framework to define velocity in a relevant manner. For instance, the very concept of instantaneous speed simply does not exist under one of the most popular approaches that models the evolution of spatial coordinates as Brownian trajectories running along a phylogeny.
View Article and Find Full Text PDFWe develop a simulation framework for studying misinformation spread within online social networks that blends agent-based modeling and natural language processing techniques. While many other agent-based simulations exist in this space, questions over their fidelity and generalization to existing networks in part hinder their ability to drive policy-relevant decision making. To partially address these concerns, we create a 'digital clone' of a known misinformation sharing network by downloading social media histories for over ten thousand of its users.
View Article and Find Full Text PDFSocio-economic disparities were associated with disproportionate viral incidence between neighborhoods of New York City (NYC) during the first wave of SARS-CoV-2. We investigated how these disparities affected the co-circulation of SARS-CoV-2 variants during the second wave in NYC. We tested for correlation between the prevalence, in late 2020/early 2021, of Alpha, Iota, Iota with E484K mutation (Iota-E484K), and B.
View Article and Find Full Text PDFAccurate estimation of the dispersal velocity or speed of evolving organisms is no mean feat. In fact, existing probabilistic models in phylogeography or spatial population genetics generally do not provide an adequate framework to define velocity in a relevant manner. For instance, the very concept of instantaneous speed simply does not exist under one of the most popular approaches that models the evolution of spatial coordinates as Brownian trajectories running along a phylogeny (Lemey et al.
View Article and Find Full Text PDFThe maturation of genomic surveillance in the past decade has enabled tracking of the emergence and spread of epidemics at an unprecedented level. During the COVID-19 pandemic, for example, genomic data revealed that local epidemics varied considerably in the frequency of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineage importation and persistence, likely due to a combination of COVID-19 restrictions and changing connectivity. Here, we show that local COVID-19 epidemics are driven by regional transmission, including across international boundaries, but can become increasingly connected to distant locations following the relaxation of public health interventions.
View Article and Find Full Text PDFBMC Neurol
March 2023
Background: Traumatic brain injury (TBI) has substantial physical, psychological, social and economic impacts, with high rates of morbidity and mortality. Considering its high incidence, the aim of this study was to identify epidemiological and clinical characteristics that predict mortality in patients hospitalized for TBI in intensive care units (ICUs).
Methods: A retrospective cohort study was carried out with patients over 18 years old with TBI admitted to an ICU of a Brazilian trauma referral hospital between January 2012 and August 2019.
Researchers studying the evolution of viral pathogens and other organisms increasingly encounter and use large and complex data sets from multiple different sources. Statistical research in Bayesian phylogenetics has risen to this challenge. Researchers use phylogenetics not only to reconstruct the evolutionary history of a group of organisms, but also to understand the processes that guide its evolution and spread through space and time.
View Article and Find Full Text PDFGenomic sequencing is essential to track the evolution and spread of SARS-CoV-2, optimize molecular tests, treatments, vaccines, and guide public health responses. To investigate the global SARS-CoV-2 genomic surveillance, we used sequences shared via GISAID to estimate the impact of sequencing intensity and turnaround times on variant detection in 189 countries. In the first two years of the pandemic, 78% of high-income countries sequenced >0.
View Article and Find Full Text PDFComparative biologists are often interested in inferring covariation between multiple biological traits sampled across numerous related taxa. To properly study these relationships, we must control for the shared evolutionary history of the taxa to avoid spurious inference. An additional challenge arises as obtaining a full suite of measurements becomes increasingly difficult with increasing taxa.
View Article and Find Full Text PDFRecent advances in Bayesian phylogenetics offer substantial computational savings to accommodate increased genomic sampling that challenges traditional inference methods. In this review, we begin with a brief summary of the Bayesian phylogenetic framework, and then conceptualize a variety of methods to improve posterior approximations via Markov chain Monte Carlo (MCMC) sampling. Specifically, we discuss methods to improve the speed of likelihood calculations, reduce MCMC burn-in, and generate better MCMC proposals.
View Article and Find Full Text PDFBackground: Monitoring the emergence and spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants is an important public health objective. We investigated how the Gamma variant was established in New York City (NYC) in early 2021 in the presence of travel restrictions that aimed to prevent viral spread from Brazil, the country where the variant was first identified.
Methods: We performed phylogeographic analysis on 15 967 Gamma sequences sampled between 10 March and 1 May 2021, to identify geographic sources of Gamma lineages introduced into NYC.
Genomic sequencing provides critical information to track the evolution and spread of SARS-CoV-2, optimize molecular tests, treatments and vaccines, and guide public health responses. To investigate the spatiotemporal heterogeneity in the global SARS-CoV-2 genomic surveillance, we estimated the impact of sequencing intensity and turnaround times (TAT) on variant detection in 167 countries. Most countries submit genomes >21 days after sample collection, and 77% of low and middle income countries sequenced <0.
View Article and Find Full Text PDFBackground: Obesity is a risk factor for increased perioperative morbidity and mortality in surgical patients. There have been limited studies to correlate the morbidity of lung cancer resection with obesity.
Methods: We performed a retrospective study of patients who underwent surgical resection for lung cancer at the Medical College of Wisconsin, Milwaukee, from 2006 to 2010.
In this study we present an unprecedented comprehensive overview of cases of infanticide in the region of Mecklenburg-Western Pomerania, from the end of the 16th century to the middle of the 19th century. Using the Faculty of Law's verdict files stored in the University of Rostock's archives, we analysed and evaluated 362 cases. Changes in the prosecution of this crime, in the way the trials were conducted and in the passing of sentences illustrate the judicial conceptions of the academics, as well as being of great social interest.
View Article and Find Full Text PDFThis report recounts one institution's experience in the fundamental reorganization of its institutional review board (IRB). With an appropriate approach, organizational structure, and ethos, the goals of research participant safety, regulatory compliance, and efficiency are not in conflict but, rather, mutually reinforcing. These important goals were realized because all aspects of the IRB reorganization were guided by and measured against five related principles: (1) expertise, (2) service, (3) credibility, (4) efficiency, and (5) accountability.
View Article and Find Full Text PDFBiochem Biophys Res Commun
August 2005
Endostatin is a potent inhibitor of angiogenesis and tumor growth. Here, we used human endothelial cells from lung capillaries to investigate if endostatin competes with the proangiogenic growth factors, bFGF and VEGF, for binding to costimulatory heparan sulfate molecules. Endostatin inhibited 79% and 95% of the increase in proliferation induced by bFGF and VEGF165, respectively.
View Article and Find Full Text PDFObjective: The growth behaviour of well-differentiated neuroendocrine carcinomas of the gastro-entero-pancreatic system varies greatly and parameters predicting their prognosis are lacking. The aim of our study was to investigate whether tumour growth could be correlated with the release of proangiogenic factors into the circulation.
Patients And Methods: Circulating vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), basic fibroblast growth factor (bFGF) and angiogenin were measured in 38 patients with advanced neuroendocrine carcinomas and compared to healthy age-matched controls.
We have used northern blot analysis and quantitative reverse transcription polymerase chain reaction (RT-PCR) to determine the postinjury expression profile of the transforming growth factor-beta 1 (TGF-beta 1) gene in the contused rat spinal cord. Spectrophotometric estimates of total sample RNA and quantitative analyses of cyclophilin mRNA using RT-PCR served as controls for comparisons between samples. No changes in cyclophilin gene expression were found at any postinjury survival times.
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