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1.
Mol Biol Evol ; 40(4)2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36947126

RESUMO

Gene flow between previously differentiated populations during the founding of an admixed or hybrid population has the potential to introduce adaptive alleles into the new population. If the adaptive allele is common in one source population, but not the other, then as the adaptive allele rises in frequency in the admixed population, genetic ancestry from the source containing the adaptive allele will increase nearby as well. Patterns of genetic ancestry have therefore been used to identify post-admixture positive selection in humans and other animals, including examples in immunity, metabolism, and animal coloration. A common method identifies regions of the genome that have local ancestry "outliers" compared with the distribution across the rest of the genome, considering each locus independently. However, we lack theoretical models for expected distributions of ancestry under various demographic scenarios, resulting in potential false positives and false negatives. Further, ancestry patterns between distant sites are often not independent. As a result, current methods tend to infer wide genomic regions containing many genes as under selection, limiting biological interpretation. Instead, we develop a deep learning object detection method applied to images generated from local ancestry-painted genomes. This approach preserves information from the surrounding genomic context and avoids potential pitfalls of user-defined summary statistics. We find the method is robust to a variety of demographic misspecifications using simulated data. Applied to human genotype data from Cabo Verde, we localize a known adaptive locus to a single narrow region compared with multiple or long windows obtained using two other ancestry-based methods.


Assuntos
Genética Populacional , Genômica , Animais , Humanos , Genômica/métodos , Genótipo , Fluxo Gênico , Cromossomos
3.
Nature ; 557(7705): 369-374, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29743675

RESUMO

For thousands of years the Eurasian steppes have been a centre of human migrations and cultural change. Here we sequence the genomes of 137 ancient humans (about 1× average coverage), covering a period of 4,000 years, to understand the population history of the Eurasian steppes after the Bronze Age migrations. We find that the genetics of the Scythian groups that dominated the Eurasian steppes throughout the Iron Age were highly structured, with diverse origins comprising Late Bronze Age herders, European farmers and southern Siberian hunter-gatherers. Later, Scythians admixed with the eastern steppe nomads who formed the Xiongnu confederations, and moved westward in about the second or third century BC, forming the Hun traditions in the fourth-fifth century AD, and carrying with them plague that was basal to the Justinian plague. These nomads were further admixed with East Asian groups during several short-term khanates in the Medieval period. These historical events transformed the Eurasian steppes from being inhabited by Indo-European speakers of largely West Eurasian ancestry to the mostly Turkic-speaking groups of the present day, who are primarily of East Asian ancestry.


Assuntos
Povo Asiático/genética , Genoma Humano/genética , Pradaria , Filogenia , População Branca/genética , Ásia/etnologia , Europa (Continente)/etnologia , Fazendeiros/história , História Antiga , Migração Humana/história , Humanos
4.
PLoS Genet ; 17(3): e1009374, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33705374

RESUMO

Throughout human history, large-scale migrations have facilitated the formation of populations with ancestry from multiple previously separated populations. This process leads to subsequent shuffling of genetic ancestry through recombination, producing variation in ancestry between populations, among individuals in a population, and along the genome within an individual. Recent methodological and empirical developments have elucidated the genomic signatures of this admixture process, bringing previously understudied admixed populations to the forefront of population and medical genetics. Under this theme, we present a collection of recent PLOS Genetics publications that exemplify recent progress in human genetic admixture studies, and we discuss potential areas for future work.


Assuntos
Variação Genética , Genética Populacional , Genética Humana , Modelos Genéticos , Alelos , Genoma Humano , Geografia , Haplótipos , Humanos , Locos de Características Quantitativas , Seleção Genética
5.
Mol Biol Evol ; 38(11): 5051-5065, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34343337

RESUMO

Throughout its distribution across Eurasia, domestic pig (Sus scrofa) populations have acquired differences through natural and artificial selection, and have often interbred. We resequenced 80 Eurasian pigs from nine different Asian and European breeds; we identify 42,288 reliable SNPs on the Y chromosome in a panel of 103 males, among which 96.1% are newly detected. Based on these new data, we elucidate the evolutionary history of pigs through the lens of the Y chromosome. We identify two highly divergent haplogroups: one present only in Asia and one fixed in Europe but present in some Asian populations. Analyzing the European haplotypes present in Asian populations, we find evidence of three independent waves of introgression from Europe to Asia in last 200 years, agreeing well with the literature and historical records. The diverse European lineages were brought in China by humans and left significant imprints not only on the autosomes but also on the Y chromosome of geographically and genetically distinct Chinese pig breeds. We also find a general excess of European ancestry on Y chromosomes relative to autosomes in Chinese pigs, an observation that cannot be explained solely by sex-biased migration and genetic drift. The European Y haplotype is associated with leaner meat production, and we hypothesize that the European Y chromosome increased in frequency in Chinese populations due to artificial selection. We find evidence of Y chromosomal gene flow between Sumatran wild boar and Chinese pigs. Our results demonstrate how human-mediated admixture and selection shaped the distribution of modern swine Y chromosomes.


Assuntos
Cruzamento , Cromossomo Y , Animais , Evolução Biológica , Haplótipos , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Sus scrofa/genética , Suínos/genética , Cromossomo Y/genética
6.
J Surg Res ; 278: 1-6, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35588570

RESUMO

INTRODUCTION: "Talk and die" traditionally described occult presentations of fatal intracranial injuries, but we broaden its definition to victims of penetrating trauma. METHODS: We conducted a descriptive analysis of patients with penetrating torso trauma who presented with a Glasgow Coma Scale verbal score ≥3 and died within 48 h of arrival from 2008 to 2018. RESULTS: Sixty patients were identified. Eighteen (30.0%) required resuscitative thoracotomy with 7 (11.7%) dying in the trauma bay. Fifty-three (86.9%) patients went to the operating room, and 35 (66.0%) required multicavitary exploration. The most common injuries were hollow viscous (58.5%), intra-abdominal vascular (49.0%), liver (28.3%), pulmonary (26.4%), intrathoracic vascular (18.9%), and cardiac (15.75) injuries. Twenty-three (43.4%) patients survived their initial operation, but died in the first 48 h postoperatively. CONCLUSIONS: Patients who "talk and die" most frequently have intra-abdominal vascular injures and require multicavitary exploration.


Assuntos
Ferimentos Penetrantes , Escala de Coma de Glasgow , Humanos , Ressuscitação , Estudos Retrospectivos , Toracotomia , Ferimentos Penetrantes/complicações , Ferimentos Penetrantes/cirurgia
7.
Prev Med ; 158: 107020, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35301043

RESUMO

Recent increases in firearm violence in U.S. cities are well-documented, however dynamic changes in the people, places and intensity of this public health threat during the COVID-19 pandemic are relatively unexplored. This descriptive epidemiologic study spanning from January 1, 2015 - March 31, 2021 utilizes the Philadelphia Police Department's registry of shooting victims, a database which includes all individuals shot and/or killed due to interpersonal firearm violence in the city of Philadelphia. We compared victim and event characteristics prior to the pandemic with those following implementation of pandemic containment measures. In this study, containment began on March 16, 2020, when non-essential businesses were ordered to close in Philadelphia. There were 331 (SE = 13.9) individuals shot/quarter pre-containment vs. 545 (SE = 66.4) individuals shot/quarter post-containment (p = 0.031). Post-containment, the proportion of women shot increased by 39% (95% CI: 1.21, 1.59), and the proportion of children shot increased by 17% (95% CI: 1.00, 1.35). Black women and children were more likely to be shot post-containment (RR 1.11, 95% CI: 1.02, 1.20 and RR 1.08, 95% CI: 1.03, 1.14, respectively). The proportion of mass shootings (≥4 individuals shot within 100 m within 1 h) increased by 53% post-containment (95% CI: 1.25, 1.88). Geographic analysis revealed relative increases in all shootings and mass shootings in specific city locations post-containment. The observed changes in firearm injury epidemiology following COVID-19 containment in Philadelphia demonstrate an intensification in firearm violence, which is increasingly impacting people who are likely made more vulnerable by existing social and structural disadvantage. These findings support existing knowledge about structural causes of interpersonal firearm violence and suggest structural solutions are required to address this public health threat.


Assuntos
COVID-19 , Armas de Fogo , Ferimentos por Arma de Fogo , COVID-19/epidemiologia , Criança , Feminino , Humanos , Pandemias , Philadelphia/epidemiologia , Violência , Ferimentos por Arma de Fogo/epidemiologia
8.
Nature ; 532(7598): 232-5, 2016 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-27049941

RESUMO

As the last habitable continent colonized by humans, the site of multiple domestication hotspots, and the location of the largest Pleistocene megafaunal extinction, South America is central to human prehistory. Yet remarkably little is known about human population dynamics during colonization, subsequent expansions, and domestication. Here we reconstruct the spatiotemporal patterns of human population growth in South America using a newly aggregated database of 1,147 archaeological sites and 5,464 calibrated radiocarbon dates spanning fourteen thousand to two thousand years ago (ka). We demonstrate that, rather than a steady exponential expansion, the demographic history of South Americans is characterized by two distinct phases. First, humans spread rapidly throughout the continent, but remained at low population sizes for 8,000 years, including a 4,000-year period of 'boom-and-bust' oscillations with no net growth. Supplementation of hunting with domesticated crops and animals had a minimal impact on population carrying capacity. Only with widespread sedentism, beginning ~5 ka, did a second demographic phase begin, with evidence for exponential population growth in cultural hotspots, characteristic of the Neolithic transition worldwide. The unique extent of humanity's ability to modify its environment to markedly increase carrying capacity in South America is therefore an unexpectedly recent phenomenon.


Assuntos
Migração Humana/história , Dinâmica Populacional/história , Agricultura/história , Arqueologia , Clima , Mapeamento Geográfico , História Antiga , Humanos , Datação Radiométrica , Sibéria/etnologia , América do Sul
9.
J Surg Res ; 264: 51-57, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33773321

RESUMO

BACKGROUND: Fresh frozen plasma (FFP) contains proinflammatory mediators released from cellular debris during frozen storage. In addition, recent studies have shown that transfusion of never-frozen plasma (NFP), instead of FFP, may be superior in trauma patients. We hypothesized that FFP would have higher levels of inflammatory mediators when compared to NFP. MATERIALS AND METHODS: FFP (n = 8) and NFP (n = 8) samples were obtained from an urban, level 1 trauma center blood bank. The cytokines in these samples were compared using a Milliplex (Milliplex Sigma) human cytokine magnetic bead panel multiplex assay for 41 different biomarkers. RESULTS: Growth factors that were higher in NFP included platelet-derived growth factor-AA (PDGF-AA; 8.09 versus 108.00 pg/mL, P < 0.001) and PDGF-AB (0.00 versus 215.20, P= 0.004). Soluble CD40-ligand (sCD40L), a platelet activator and pro-coagulant, was higher in NFP (31.81 versus 80.45 pg/mL, P< 0.001). RANTES, a leukocyte chemotactic cytokine was higher in NFP (26.19 versus 1418.00 pg/mL, P< 0.001). Interleukin-4 (5.70 versus 0.00 pg/mL, P= 0.03) and IL-8 (2.20 versus 0.52 pg/ml, P= 0.03) levels were higher in were higher in FFP. CONCLUSIONS: Frozen storage of plasma may result in decrease of several growth factors and/or pro-coagulants found in NFP. In addition, the freezing and thawing process may induce release of pro-inflammatory chemokines. Further studies are needed to determine if these cytokines result in improved outcomes with NFP over FFP in transfusion of trauma patients.


Assuntos
Preservação de Sangue/efeitos adversos , Criopreservação , Citocinas/análise , Peptídeos e Proteínas de Sinalização Intercelular/análise , Plasma/química , Transfusão de Componentes Sanguíneos/métodos , Preservação de Sangue/métodos , Citocinas/imunologia , Humanos , Plasma/imunologia , Resultado do Tratamento , Ferimentos e Lesões/terapia
10.
Am J Phys Anthropol ; 175(2): 406-421, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33772750

RESUMO

OBJECTIVES: In genetic admixture processes, source groups for an admixed population possess distinct patterns of genotype and phenotype at the onset of admixture. Particularly in the context of recent and ongoing admixture, such differences are sometimes taken to serve as markers of ancestry for individuals-that is, phenotypes initially associated with the ancestral background in one source population are assumed to continue to reflect ancestry in that population. Such phenotypes might possess ongoing significance in social categorizations of individuals, owing in part to perceived continuing correlations with ancestry. However, genotypes or phenotypes initially associated with ancestry in one specific source population have been seen to decouple from overall admixture levels, so that they no longer serve as proxies for genetic ancestry. Here, we aim to develop an understanding of the joint dynamics of admixture levels and phenotype distributions in an admixed population. METHODS: We devise a mechanistic model, consisting of an admixture model, a quantitative trait model, and a mating model. We analyze the behavior of the mechanistic model in relation to the model parameters. RESULTS: We find that it is possible for the decoupling of genetic ancestry and phenotype to proceed quickly, and that it occurs faster if the phenotype is driven by fewer loci. Positive assortative mating attenuates the process of dissociation relative to a scenario in which mating is random with respect to genetic admixture and with respect to phenotype. CONCLUSIONS: The mechanistic framework suggests that in an admixed population, a trait that initially differed between source populations might serve as a reliable proxy for ancestry for only a short time, especially if the trait is determined by few loci. It follows that a social categorization based on such a trait is increasingly uninformative about genetic ancestry and about other traits that differed between source populations at the onset of admixture.


Assuntos
Frequência do Gene/genética , Genética Populacional , Antropologia Física , Feminino , Fluxo Gênico/genética , Genoma Humano/genética , Genótipo , Humanos , Masculino , Fenótipo , Pigmentação da Pele/genética
11.
Pediatr Emerg Care ; 37(4): e159-e162, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30870343

RESUMO

ABSTRACT: Substance use and abuse have been documented as both a risk factor in and consequence of involvement in domestic minor sex trafficking (DMST). Domestic minor sex trafficking is defined as the commercial sexual exploitation of children in exchange for money, food, shelter, or any other valued entity. The current investigation sought to describe substance use in a cohort of DMST patients who present for medical evaluation. Findings revealed that 68 patients referred for DMST involvement reported high rates of alcohol/substance use and parental substance abuse. Further, many patients who had a urine toxicology screen had a positive result, most often identifying the presence of cannabinoids. Our data may inform the importance of comprehensive assessments and specialized interventions for substance abuse in this unique patient population.


Assuntos
Abuso Sexual na Infância , Maus-Tratos Infantis , Tráfico de Pessoas , Transtornos Relacionados ao Uso de Substâncias , Criança , Humanos , Comportamento Sexual , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
12.
Pediatr Emerg Care ; 37(12): e1409-e1415, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32371752

RESUMO

OBJECTIVE: The objective of this study was to determine the prevalence of rib fractures (RFs) identified by chest x-ray (CXR) among children younger than 2 years who sustained accidental versus nonaccidental injuries. It is hypothesized that RFs are uncommon among all accidental pediatric trauma mechanisms (eg, falls, motor vehicle crashes) as compared with the prevalence of RFs in the setting of nonaccidental trauma (NAT). METHODS: A retrospective chart review of sequential CXRs of children younger than 2 years evaluated at a pediatric level 1 trauma center for accidental trauma and possible NAT was conducted from January 1, 2011, to October 31, 2016. Data collected included demographics, CXR indication and findings, history of cardiopulmonary resuscitation, trauma mechanism, associated injuries, final diagnoses, and outcomes. RESULTS: Two (<1%) of 226 CXRs obtained to evaluate accidental trauma demonstrated acute RFs. Ten (19.6%) of 51 CXRs obtained in the setting of concern for NAT revealed RFs (9/10 identified only healing RFs and 1/10 identified acute RFs). Among patients with a final diagnosis of NAT (ie, not neglect, accidental trauma, etc; n = 38), the overall prevalence increased to 26.3%. CONCLUSIONS: The presence of RFs in pediatric accidental trauma is uncommon even in the setting of high-force mechanisms, and when identified, these RFs are acute. Comparatively, the overall prevalence of RFs identified on CXR among cases with a final diagnosis of NAT was much higher and almost exclusively healing RFs. These data provide support that identification of RFs is highly concerning for NAT even if an accidental mechanism is provided. When RFs are identified, a full NAT work-up should be considered.


Assuntos
Maus-Tratos Infantis , Fraturas das Costelas , Acidentes por Quedas , Criança , Maus-Tratos Infantis/diagnóstico , Humanos , Lactente , Estudos Retrospectivos , Fraturas das Costelas/diagnóstico por imagem , Fraturas das Costelas/epidemiologia , Fraturas das Costelas/etiologia , Centros de Traumatologia
13.
Pediatr Emerg Care ; 37(2): 62-69, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30422944

RESUMO

OBJECTIVE: Close medical follow-up after pediatric acute sexual assault is recommended and may mitigate adverse consequences and decrease long-term comorbidities. The objectives are to (1) examine adherence to a comprehensive outpatient medical follow-up protocol after evaluation in the emergency department in a pediatric population and (2) identify characteristics associated with patient adherence to inform the utilization of a medical follow-up protocol after pediatric acute sexual assault. METHODS: A retrospective medical record review was conducted of patients younger than 18 years presenting to the emergency department from January 1, 2010, to December 31, 2013, with a discharge diagnosis suggestive of sexual assault/abuse. We examined differences in demographics, assault characteristics, and medical/legal needs of patients who were evaluated in follow-up versus patients who were not. RESULTS: Of 182 patients, 60.4% completed follow-up appointments with the child protection center. Younger patients had follow-up rates higher than older patients (70.2% vs 50%; odds ratio [OR], 0.42). For patients where child protective services or law enforcement were called, follow-up rates were 74.2% and 64.7%, respectively (OR, 2.5; OR, 3.1). All patients with anogenital injuries on initial examination were seen in follow-up. The majority of patients who followed-up were accompanied by a caregiver/relative (95%). CONCLUSIONS: (1) Caregivers should be integrated into the evaluation to facilitate compliance with follow-up; (2) child abuse specialists may be consulted to facilitate specific interventions and recommendations; (3) professionals should work as a multidisciplinary team; and (4) the patient's psychological status should be evaluated, and mental health interventions recommended.


Assuntos
Abuso Sexual na Infância , Pacientes Ambulatoriais , Delitos Sexuais , Criança , Abuso Sexual na Infância/diagnóstico , Abuso Sexual na Infância/terapia , Serviço Hospitalar de Emergência , Seguimentos , Humanos , Estudos Retrospectivos
14.
J Child Sex Abus ; 30(6): 667-683, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34296663

RESUMO

Males, in particular adolescents and young adults, have been increasingly recognized as involved in domestic minor sex trafficking (DMST). However, there are very sparse resources and organizations that provide prevention, identification, and interventions for boys and young men who are involved in or at-risk for DMST involvement. The objective was to develop and assess an educational curriculum to prevent adolescent male involvement in DMST through a three-pronged educational approach: as victims of sexual exploitation; receiving financial benefit as exploiters; as buyers of sex. Through quality improvement cycles, changes were made to enhance the curriculum by utilizing the outcome measures of participant questionnaires and feedback from a steering committee of clinical experts. Male youth at the state's juvenile detention center were asked to participate in pilot groups, as they were identified as a high-risk population of adolescents to become involved. The curriculum was modified by adding sessions, including additional community guest speakers, and providing a more holistic educational experience that involves trafficking prevention from both a victimization and perpetration standpoint. Our goal is to expand this educational opportunity to be utilized in multiple settings (e.g., schools, hospitals) across the country.


Assuntos
Abuso Sexual na Infância , Vítimas de Crime , Tráfico de Pessoas , Adolescente , Criança , Currículo , Tráfico de Pessoas/prevenção & controle , Humanos , Masculino , Comportamento Sexual , Adulto Jovem
15.
Mol Biol Evol ; 36(10): 2358-2374, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31165149

RESUMO

Natural populations display a variety of spatial arrangements, each potentially with a distinctive impact on genetic diversity and genetic differentiation among subpopulations. Although the spatial arrangement of populations can lead to intricate migration networks, theoretical developments have focused mainly on a small subset of such networks, emphasizing the island-migration and stepping-stone models. In this study, we investigate all small network motifs: the set of all possible migration networks among populations subdivided into at most four subpopulations. For each motif, we use coalescent theory to derive expectations for three quantities that describe genetic variation: nucleotide diversity, FST, and half-time to equilibrium diversity. We describe the impact of network properties on these quantities, finding that motifs with a high mean node degree have the largest nucleotide diversity and the longest time to equilibrium, whereas motifs with low density have the largest FST. In addition, we show that the motifs whose pattern of variation is most strongly influenced by loss of a connection or a subpopulation are those that can be split easily into disconnected components. We illustrate our results using two example data sets-sky island birds of genus Sholicola and Indian tigers-identifying disturbance scenarios that produce the greatest reduction in genetic diversity; for tigers, we also compare the benefits of two assisted gene flow scenarios. Our results have consequences for understanding the effect of geography on genetic diversity, and they can assist in designing strategies to alter population migration networks toward maximizing genetic variation in the context of conservation of endangered species.


Assuntos
Migração Animal , Genética Populacional/métodos , Animais , Aves/genética , Variação Genética , Tigres/genética
16.
Proc Biol Sci ; 287(1927): 20200447, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32429803

RESUMO

The human-mediated movement of species across biogeographic boundaries-whether intentional or accidental-is dramatically reshaping the modern world. Yet humans have been reshaping ecosystems and translocating species for millennia, and acknowledging the deeper roots of these phenomena is important for contextualizing present-day biodiversity loss, ecosystem functioning and management needs. Here, we present the first database of terrestrial vertebrate species introductions spanning the entire anthropogenic history of a system: the Caribbean. We employ this approximately 7000-year dataset to assess the roles of historical contingency and priority effects in shaping present-day community structure and conservation outcomes, finding that serial human colonization events contributed to habitat modifications and species extinctions that shaped the trajectories of subsequent species introductions by other human groups. We contextualized spatial and temporal patterns of species introductions within cultural practices and population histories of Indigenous, colonial and modern human societies, and show that the taxonomic and biogeographic diversity of introduced species reflects diversifying reasons for species introductions through time. Recognition of the complex social and economic structures across the 7000-year human history of the Caribbean provides the necessary context for interpreting the formation of an Anthropocene biota.


Assuntos
Biodiversidade , Ecossistema , Animais , Biota , Região do Caribe , Conservação dos Recursos Naturais , Extinção Biológica , Humanos , Espécies Introduzidas
17.
Theor Popul Biol ; 134: 129-146, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32275920

RESUMO

Populations whose mating pairs have levels of similarity in phenotypes or genotypes that differ systematically from the level expected under random mating are described as experiencing assortative mating. Excess similarity in mating pairs is termed positive assortative mating, and excess dissimilarity is negative assortative mating. In humans, empirical studies suggest that mating pairs from various admixed populations - whose ancestry derives from two or more source populations - possess correlated ancestry components that indicate the occurrence of positive assortative mating on the basis of ancestry. Generalizing a two-sex mechanistic admixture model, we devise a model of one form of ancestry-assortative mating that occurs through preferential mating based on source population. Under the model, we study the moments of the admixture fraction distribution for different assumptions about mating preferences, including both positive and negative assortative mating by population. We demonstrate that whereas the mean admixture under assortative mating is equivalent to that of a corresponding randomly mating population, the variance of admixture depends on the level and direction of assortative mating. We consider two special cases of assortative mating by population: first, a single admixture event, and second, constant contributions to the admixed population over time. In contrast to standard settings in which positive assortment increases variation within a population, certain assortative mating scenarios allow the variance of admixture to decrease relative to a corresponding randomly mating population: with the three populations we consider, the variance-increasing effect of positive assortative mating within a population might be overwhelmed by a variance-decreasing effect emerging from mating preferences involving other pairs of populations. The effect of assortative mating is smaller on the X chromosome than on the autosomes because inheritance of the X in males depends only on the mother's ancestry, not on the mating pair. Because the variance of admixture is informative about the timing of admixture and possibly about sex-biased admixture contributions, the effects of assortative mating are important to consider in inferring features of population history from distributions of admixture values. Our model provides a framework to quantitatively study assortative mating under flexible scenarios of admixture over time.


Assuntos
Genética Populacional , Reprodução , Genótipo , Humanos , Masculino , Fenótipo
18.
Proc Natl Acad Sci U S A ; 114(10): 2657-2662, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28223527

RESUMO

Dramatic events in human prehistory, such as the spread of agriculture to Europe from Anatolia and the late Neolithic/Bronze Age migration from the Pontic-Caspian Steppe, can be investigated using patterns of genetic variation among the people who lived in those times. In particular, studies of differing female and male demographic histories on the basis of ancient genomes can provide information about complexities of social structures and cultural interactions in prehistoric populations. We use a mechanistic admixture model to compare the sex-specifically-inherited X chromosome with the autosomes in 20 early Neolithic and 16 late Neolithic/Bronze Age human remains. Contrary to previous hypotheses suggested by the patrilocality of many agricultural populations, we find no evidence of sex-biased admixture during the migration that spread farming across Europe during the early Neolithic. For later migrations from the Pontic Steppe during the late Neolithic/Bronze Age, however, we estimate a dramatic male bias, with approximately five to 14 migrating males for every migrating female. We find evidence of ongoing, primarily male, migration from the steppe to central Europe over a period of multiple generations, with a level of sex bias that excludes a pulse migration during a single generation. The contrasting patterns of sex-specific migration during these two migrations suggest a view of differing cultural histories in which the Neolithic transition was driven by mass migration of both males and females in roughly equal numbers, perhaps whole families, whereas the later Bronze Age migration and cultural shift were instead driven by male migration, potentially connected to new technology and conquest.


Assuntos
Cromossomos Humanos X/genética , História Antiga , Migração Humana/história , Sexismo/história , Restos Mortais , DNA Mitocondrial/genética , Europa (Continente) , Feminino , Humanos , Masculino
19.
J Pediatr ; 204: 208-213, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30297294

RESUMO

OBJECTIVES: To determine the prevalence of incidental rib fractures identified by chest radiograph (CXR) obtained for indications unrelated to accidental trauma or nonaccidental trauma (NAT), and describe the histories associated with cases of incidental rib fractures and their proposed etiologies. It is hypothesized that incidental rib fractures are rare and alternative explanations for rib fractures occasionally used in a medico-legal context such as minor accidental trauma, undiagnosed medical conditions, and transient metabolic bone disturbances are unlikely to be the etiology of incidental rib fractures. STUDY DESIGN: A retrospective chart review of sequential CXRs of children ages 0 to <2 years was conducted from January 1, 2011 to October 31, 2016. CXRs were obtained in the emergency department, general pediatric or intensive care units, or outpatient pediatric clinics. Data collected included demographics, CXR indication and findings, history of cardiopulmonary resuscitation, laboratory and additional imaging results, and incidental rib fracture descriptions and proposed etiologies. RESULTS: A total of 7530 patients underwent 9720 CXRs associated with unique clinical encounters. Five CXRs had incidental rib fractures identified, making the prevalence of CXRs with incidental rib fractures in this cohort <0.1%. Of 5 identified incidental cases, mean age was 3.6 months, 3 were concerning for NAT, 1 was confirmed NAT, and 1 had radiographic findings consistent with osteopenia of prematurity. CONCLUSIONS: Identification of incidental rib fracture on CXR is rare. When detected in the absence of corresponding trauma history and/or objective laboratory or radiographic metabolic abnormalities, work-up for NAT should be pursued.


Assuntos
Achados Incidentais , Fraturas das Costelas/epidemiologia , Tórax/diagnóstico por imagem , Feminino , Humanos , Lactente , Masculino , Prevalência , Estudos Retrospectivos , Fraturas das Costelas/diagnóstico por imagem
20.
J Surg Res ; 239: 278-283, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30897515

RESUMO

BACKGROUND: We sought to investigate associations between race, clinical characteristics, and outcomes among patients with malignant phyllodes of the breast. METHODS: Malignant phyllodes cases were identified using Surveillance Epidemiology and End Results database. We used chi-square tests to compare characteristics between racial groups and multinomial logistic regression to calculate relative risk ratios (RRR) and 95% confidence intervals (CI) comparing the likelihood of having particular characteristics by race. Survival analyses included Cox regression and Kaplan-Meier functions. RESULTS: Among 1202 patients included, mean age was 51.7 y and 55.2% were white. Compared to whites, blacks were younger (mean age 45.7 versus 55.1 y; P < 0.001), and more likely to have tumors 51-100 mm (RRR = 1.91; 95% CI: 1.20-3.05) and tumors > 100 mm (RRR = 2.52; 95% CI: 1.56-4.05) than tumors ≤ 50 mm in size. Compared to whites, Hispanics were younger (mean age 46.7 versus 55.1 y; P < 0.001), and more likely to have tumors 51-100 mm (RRR = 1.46; 95% CI: 1.01-2.11) than tumors ≤ 50 mm in size. Asians were more likely to have tumors 51-100 mm (RRR = 1.52; 95% CI: 1.01-2.30) and tumors > 100 mm (RRR = 1.61; 95% CI: 1.03-2.52) than tumors ≤ 50 mm in size, and more likely to have tumors that extended beyond the breast tissue (RRR = 1.87; 95% CI: 1.05-3.31), compared to whites. Survival was similar for blacks (HR = 1.48; 95% CI: 0.80-2.76), Hispanics (HR = 1.02; 95% CI: 0.54-1.93), and Asians (HR = 1.13; 95% CI: 0.63-2.01) compared to whites. CONCLUSIONS: Further research into factors contributing to extensive disease at presentation among minorities is warranted.


Assuntos
Neoplasias da Mama/epidemiologia , Mama/patologia , Disparidades nos Níveis de Saúde , Tumor Filoide/epidemiologia , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Povo Asiático/estatística & dados numéricos , Mama/cirurgia , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Feminino , Hispânico ou Latino/estatística & dados numéricos , Humanos , Mastectomia/estatística & dados numéricos , Pessoa de Meia-Idade , Tumor Filoide/patologia , Tumor Filoide/terapia , Radioterapia Adjuvante/estatística & dados numéricos , Fatores de Risco , Programa de SEER/estatística & dados numéricos , Análise de Sobrevida , Resultado do Tratamento , Carga Tumoral , Estados Unidos/epidemiologia , População Branca/estatística & dados numéricos
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