Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 653
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 120(4): e2209480119, 2023 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-36649403

RESUMO

Around 10,000 y ago in southwest Asia, the cessation of a mobile lifestyle and the emergence of the first village communities during the Neolithic marked a fundamental change in human history. The first communities were small (tens to hundreds of individuals) but remained semisedentary. So-called megasites appeared soon after, occupied by thousands of more sedentary inhabitants. Accompanying this shift, the material culture and ancient ecological data indicate profound changes in economic and social behavior. A shift from residential to logistical mobility and increasing population size are clear and can be explained by either changes in fertility and/or aggregation of local groups. However, as sedentism increased, small early communities likely risked inbreeding without maintaining or establishing exogamous relationships typical of hunter-gatherers. Megasites, where large populations would have made endogamy sustainable, could have avoided this risk. To examine the role of kinship practices in the rise of megasites, we measured strontium and oxygen isotopes in tooth enamel from 99 individuals buried at Pinarbasi, Boncuklu, and Çatalhöyük (Turkey) over 7,000 y. These sites are geographically proximate and, critically, span both early sedentary behaviors (Pinarbasi and Boncuklu) and the rise of a local megasite (Çatalhöyük). Our data are consistent with the presence of only local individuals at Pinarbasi and Boncuklu, whereas at Çatalhöyük, several nonlocals are present. The Çatalhöyük data stand in contrast to other megasites where bioarchaeological evidence has pointed to strict endogamy. These different kinship behaviors suggest that megasites may have arisen by employing unique, community-specific kinship practices.


Assuntos
Estilo de Vida , Comportamento Social , Humanos , História Antiga , Turquia , Estrôncio , Comportamento Sedentário
2.
Nano Lett ; 24(37): 11376-11384, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39231528

RESUMO

There is evidence of the presence of intercalated water between graphene and the substrate in electronic devices. However, a proper understanding of the impact of this phenomenon, which causes important limitations for the optimization of graphene-based devices operating in aqueous electrolytes, is missing. We used graphene-based electrodes on insulating and conducting substrates to evaluate the impact of intercalated water by combining experimental techniques with numerical simulations. Results show that the capacitance of the conductive substrate/graphene electrodes is significantly higher than that of the insulating substrate/graphene ones. Meanwhile, Raman spectroscopy demonstrates that graphene charge modulation with the applied potential is independent of the substrate conductivity. We found that this intriguing behavior is influenced by the water intercalation phenomena and governed by the substrate conductive nature. This work contributes to the understanding of the electric response of graphene-based devices in an aqueous environment and of the methods to measure and model it.

3.
Radiographics ; 44(10): e240035, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39264836

RESUMO

Sinonasal neoplasms are a remarkably heterogeneous group, reflecting the numerous tissue types present in the nasal cavity and paranasal sinuses. These entities can be relatively benign (ie, respiratory epithelial adenomatoid hamartoma) or can be exceedingly aggressive (ie, NUT carcinoma). Certain sinonasal tumors have a propensity to spread through local invasion and destruction, while others have a high likelihood of perineural spread. The genetic and molecular mechanisms underlying sinonasal tumor behavior have recently become better understood, and new tumor types have been described using these genetic and molecular data. This has prompted an expansion in the number of tumors included in the World Health Organization fifth edition classification system for head and neck tumors, along with a new classification structure. Radiologists' familiarity with this classification structure is crucial to understanding the expected behavior of these tumors and to collaboration with the multidisciplinary cancer care board in making decisions for optimal patient care. ©RSNA, 2024.


Assuntos
Neoplasias dos Seios Paranasais , Humanos , Neoplasias dos Seios Paranasais/diagnóstico por imagem , Neoplasias dos Seios Paranasais/terapia , Equipe de Assistência ao Paciente , Neoplasias Nasais/diagnóstico por imagem , Neoplasias Nasais/terapia
4.
Proc Natl Acad Sci U S A ; 118(28)2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34260380

RESUMO

Catastrophic decline of Indigenous populations in the Americas following European contact is one of the most severe demographic events in the history of humanity, but uncertainty persists about the timing and scale of the collapse, which has implications for not only Indigenous history but also the understanding of historical ecology. A long-standing hypothesis that a continent-wide pandemic broke out immediately upon the arrival of Spanish seafarers has been challenged in recent years by a model of regional epidemics erupting asynchronously, causing different rates of population decline in different areas. Some researchers have suggested that, in California, significant depopulation occurred during the first two centuries of the post-Columbus era, which led to a "rebound" in native flora and fauna by the time of sustained European contact after 1769. Here, we combine a comprehensive prehistoric osteological dataset (n = 10,256 individuals) with historic mission mortuary records (n = 23,459 individuals) that together span from 3050 cal BC to AD 1870 to systematically evaluate changes in mortality over time by constructing life tables and conducting survival analysis of age-at-death records. Results show that a dramatic shift in the shape of mortality risk consistent with a plague-like population structure began only after sustained contact with European invaders, when permanent Spanish settlements and missions were established ca. AD 1770. These declines reflect the syndemic effects of newly introduced diseases and the severe cultural disruption of Indigenous lifeways by the Spanish colonial system.


Assuntos
Epidemias/história , Grupos Populacionais , Fatores Etários , Arqueologia , California , História do Século XVIII , História do Século XIX , Humanos , Estimativa de Kaplan-Meier
5.
Proc Natl Acad Sci U S A ; 116(26): 12615-12623, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31209020

RESUMO

The transition from a human diet based exclusively on wild plants and animals to one involving dependence on domesticated plants and animals beginning 10,000 to 11,000 y ago in Southwest Asia set into motion a series of profound health, lifestyle, social, and economic changes affecting human populations throughout most of the world. However, the social, cultural, behavioral, and other factors surrounding health and lifestyle associated with the foraging-to-farming transition are vague, owing to an incomplete or poorly understood contextual archaeological record of living conditions. Bioarchaeological investigation of the extraordinary record of human remains and their context from Neolithic Çatalhöyük (7100-5950 cal BCE), a massive archaeological site in south-central Anatolia (Turkey), provides important perspectives on population dynamics, health outcomes, behavioral adaptations, interpersonal conflict, and a record of community resilience over the life of this single early farming settlement having the attributes of a protocity. Study of Çatalhöyük human biology reveals increasing costs to members of the settlement, including elevated exposure to disease and labor demands in response to community dependence on and production of domesticated plant carbohydrates, growing population size and density fueled by elevated fertility, and increasing stresses due to heightened workload and greater mobility required for caprine herding and other resource acquisition activities over the nearly 12 centuries of settlement occupation. These changes in life conditions foreshadow developments that would take place worldwide over the millennia following the abandonment of Neolithic Çatalhöyük, including health challenges, adaptive patterns, physical activity, and emerging social behaviors involving interpersonal violence.


Assuntos
Agricultura/história , Fósseis/anatomia & histologia , Migração Humana/história , Estilo de Vida/história , Civilização/história , Nível de Saúde , História Antiga , Humanos , Turquia
6.
Clin Exp Immunol ; 203(2): 209-218, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33020895

RESUMO

Long-term observation of patients with ANCA-associated vasculitis (AAV) allows the identification of different longitudinal patterns of ANCA levels during follow-up. This study aimed to characterize these patterns and to determine their prognostic significance. All ANCA determinations performed in two university hospitals during a 2-year period were retrospectively reviewed. Patients were included in the analysis if they had high titers of anti-myeloperoxidase (anti-MPO) or anti-proteinase 3 (anti-PR3) antibodies at least once, ≥ 5 serial ANCA determinations and AAV diagnosed by biopsy or American College of Rheumatology (ACR) classification criteria. Patients' time-course ANCA patterns were classified as monophasic, remitting, recurrent or persistent. Associations between ANCA patterns and prognostic variables (relapse rate and renal outcome) were analysed by univariate and multivariate statistics. A total of 99 patients [55 with microscopic polyangiitis (MPA), 36 with granulomatosis with polyangiitis (GPA) and eight with eosinophilic granulomatosis with polyangiitis (EGPA)] were included. Median follow-up was 9 years. Among patients diagnosed with MPA or GPA, recurrent or persistent ANCA patterns were associated with a higher risk of clinical relapse [hazard ratio (HR) = 3·7, 95% confidence interval (CI) = 1·5-9·1 and HR = 2·9, 95% CI = 1·1-8·0, respectively], independently of clinical diagnosis or ANCA specificity. In patients with anti-MPO antibodies, the recurrent ANCA pattern was associated with worsening renal function [odds ratio (OR) = 5·7, 95% CI = 1·2-26·0]. Recurrent or persistent ANCA patterns are associated with a higher risk of clinical relapse. A recurrent ANCA pattern was associated with worsening renal function in anti-MPO-associated vasculitis.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/patologia , Anticorpos Anticitoplasma de Neutrófilos/metabolismo , Rim/patologia , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/metabolismo , Biópsia , Doença Crônica , Síndrome de Churg-Strauss/metabolismo , Síndrome de Churg-Strauss/patologia , Feminino , Seguimentos , Granulomatose com Poliangiite/patologia , Humanos , Rim/metabolismo , Masculino , Poliangiite Microscópica/metabolismo , Poliangiite Microscópica/patologia , Pessoa de Meia-Idade , Mieloblastina/metabolismo , Peroxidase/metabolismo , Prognóstico , Recidiva , Estudos Retrospectivos
7.
Hum Biol ; 93(1): 9-32, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35338700

RESUMO

The concept of race has a complex history in the field of biological anthropology. Despite increased recognition of the racist origins of the discipline, there remains little agreement about what the concept means, how it is used, or how it is discussed. This study presents the results of a survey of biological anthropologists to investigate the relationship of biological anthropologists with race and ancestry. The survey focuses on the areas of research, public engagement, and teaching as related to these concepts. Results indicate that a large majority of biological anthropologists agree that race (as a social not biological concept) is separate from ancestry. The majority of respondents agreed that ancestry categories should be based on geography (e.g., Asian, European, and African), and more anthropologists thought the terms "Hispanic" and "Latino" were inappropriate ancestry categories. While most respondents felt that discussions of these terms were not matters of "political correctness," nearly a quarter of respondents suggested that concerns over the moral and ethical implications of research (e.g., photos, terminology, and ancestry) result in the silencing of anthropological research. Overwhelmingly, respondents felt that anthropologists have a responsibility to ensure the avoidance of misappropriation of their work by race science and by white nationalists/supremacists. Some differences in survey responses were found relating to respondents' subdiscipline, educational level, location, age, self-identified racial/ethnic categories, and gender. In regard to teaching, survey results indicate that these concepts are minimally covered in university classrooms. When taught, topics focus on the colonialist/racist history of anthropology, the presence of white privilege/supremacy, and racism. Based on the results of this survey, the authors argue for greater public engagement on these concepts, a standardized system of teaching race and ancestry, and a disciplinary conversation about practice and terminology. In this way, biological anthropologists can best place themselves to combat racism in a socially responsible way.


Assuntos
Antropologia , Racismo , População Negra , Etnicidade , Hispânico ou Latino , Humanos
8.
Am J Phys Anthropol ; 175(1): 36-58, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33245147

RESUMO

OBJECTIVES: A fundamental assumption in biological anthropology is that living individuals will present with different growth than non-survivors of the same population. The aim is to address the question of whether growth and development data of non-survivors are reflective of the biological consequences of selective mortality and/or stress. MATERIALS AND METHODS: The study compares dental development and skeletal growth collected from radiographic images of contemporary samples of living and deceased individuals from the United States (birth to 20 years) and South Africa (birth to 12 years). Further evaluation of deceased individuals is used to explore differential patterns among manners of death (MOD). RESULTS: Results do not show any significant differences in skeletal growth or dental development between living and deceased individuals. However, in the South African deceased sample the youngest individuals exhibited substantially smaller diaphyseal lengths than the living sample, but by 2 years of age the differences were negligible. In the US sample, neither significant nor substantial differences were found in dental development or diaphyseal length according to MOD and age (>2 years of age), though some long bones in individuals <2 years of age did show significant differences. No significant differences were noted in diaphyseal length according to MOD and age in the SA sample. DISCUSSION: The current findings refute the idea that contemporary deceased and living individuals would present with differential growth and development patterns through all of ontogeny as well as the assumptions linking short stature, poor environments, and MOD.


Assuntos
Antropologia Física/métodos , Antropologia Física/normas , Osso e Ossos/anatomia & histologia , Dente/anatomia & histologia , Variação Biológica da População , Criança , Pré-Escolar , Diáfises/anatomia & histologia , Humanos , Lactente , Recém-Nascido , Mortalidade , Padrões de Referência , Viés de Seleção
9.
Proc Natl Acad Sci U S A ; 115(19): E4426-E4432, 2018 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-29686092

RESUMO

Because of the ubiquitous adaptability of our material culture, some human populations have occupied extreme environments that intensified selection on existing genomic variation. By 32,000 years ago, people were living in Arctic Beringia, and during the Last Glacial Maximum (LGM; 28,000-18,000 y ago), they likely persisted in the Beringian refugium. Such high latitudes provide only very low levels of UV radiation, and can thereby lead to dangerously low levels of biosynthesized vitamin D. The physiological effects of vitamin D deficiency range from reduced dietary absorption of calcium to a compromised immune system and modified adipose tissue function. The ectodysplasin A receptor (EDAR) gene has a range of pleiotropic effects, including sweat gland density, incisor shoveling, and mammary gland ductal branching. The frequency of the human-specific EDAR V370A allele appears to be uniquely elevated in North and East Asian and New World populations due to a bout of positive selection likely to have occurred circa 20,000 y ago. The dental pleiotropic effects of this allele suggest an even higher occurrence among indigenous people in the Western Hemisphere before European colonization. We hypothesize that selection on EDAR V370A occurred in the Beringian refugium because it increases mammary ductal branching, and thereby may amplify the transfer of critical nutrients in vitamin D-deficient conditions to infants via mothers' milk. This hypothesized selective context for EDAR V370A was likely intertwined with selection on the fatty acid desaturase (FADS) gene cluster because it is known to modulate lipid profiles transmitted to milk from a vitamin D-rich diet high in omega-3 fatty acids.


Assuntos
Clima Frio , Receptor Edar , Ácidos Graxos/metabolismo , Troca Materno-Fetal/fisiologia , Leite Humano/metabolismo , Seleção Genética/fisiologia , Vitamina D/metabolismo , Alelos , Receptor Edar/genética , Receptor Edar/metabolismo , Feminino , Humanos , Masculino , Glândulas Mamárias Humanas/anatomia & histologia , Glândulas Mamárias Humanas/metabolismo , Gravidez
10.
Tech Coloproctol ; 25(9): 1073-1078, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34173925

RESUMO

BACKGROUND: Enhanced Recovery After Surgery (ERAS) protocols are well-documented logistic programs in elective surgery but it is still uncertain whether ERAS can benefit emergency patients, because of significant challenges facing its application to emergency surgery. The aim of this study was to evaluate the implementation of an ERAS protocol for patients with acute appendicitis (AA), both complicated and uncomplicated. METHODS: A prospective observational study was performed at two university hospitals in Spain, between January 2012 and December 2019. Inclusion criteria were patients with diagnosis of AA, undergoing appendectomy following an ERAS protocol of perioperative care. The different items of the ERAS protocol were recorded and their implementation was separately evaluated. Analyzed variables also included postoperative complications, hospital stay and readmission rate. Levels of acute phase reactants were assessed as predictors of implementation for the ERAS protocol. RESULTS: Eight hundred fifty patients were included; 498 males (58.5%) and 302 females (41.5%), with a mean age of 34.95 ± 17 years. The implementation of all the items of the protocol was achieved in 770 patients (90.6%), 86.8% of patients with complicated AA and 93.1% of patients with uncomplicated AA (p = 0.02). Higher preoperative C-reactive protein (CRP) levels were significantly associated with the impossibility of implementing all the items of the ERAS protocol (p < 0.001), establishing a cut-off point at CRP = 13.5 mg/dl. CONCLUSIONS: The implementation of ERAS protocols is safe and feasible in patients with AA. Although the implementation rate of all the items is lower in patients with complicated AA, it can be completed in 86.8% of these patients. CRP levels over 13.5 mg/dl are predictors of difficulties in the implementation of all the items of ERAS protocols.


Assuntos
Apendicite , Recuperação Pós-Cirúrgica Melhorada , Adolescente , Adulto , Apendicectomia , Apendicite/cirurgia , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Observacionais como Assunto , Complicações Pós-Operatórias/etiologia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA