47 research outputs found

    Discrepancy between cranial and DNA data of early Americans: Implications for American peopling

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    Currently, one of the major debates about the American peopling focuses on the number of populations that originated the biological diversity found in the continent during the Holocene. The studies of craniometric variation in American human remains dating from that period have shown morphological differences between the earliest settlers of the continent and some of the later Amerindian populations. This led some investigators to suggest that these groups - known as Paleomericans and Amerindians respectively - may have arisen from two biologically different populations. On the other hand, most DNA studies performed over extant and ancient populations suggest a single migration of a population from Northeast Asia. Comparing craniometric and mtDNA data of diachronic samples from East Central Argentina dated from 8,000 to 400 years BP, we show here that even when the oldest individuals display traits attributable to Paleoamerican crania, they present the same mtDNA haplogroups as later populations with Amerindian morphology. A possible explanation for these results could be that the craniofacial differentiation was a local phenomenon resulting from random (i.e. genetic drift) and non-random factors (e.g. selection and plasticity). Local processes of morphological differentiation in America are a probable scenario if we take into consideration the rapid peopling and the great ecological diversity of this continent; nevertheless we will discuss alternative explanations as well.Facultad de Ciencias Naturales y Muse

    Discrepancy between cranial and DNA data of early Americans: Implications for American peopling

    Get PDF
    Currently, one of the major debates about the American peopling focuses on the number of populations that originated the biological diversity found in the continent during the Holocene. The studies of craniometric variation in American human remains dating from that period have shown morphological differences between the earliest settlers of the continent and some of the later Amerindian populations. This led some investigators to suggest that these groups - known as Paleomericans and Amerindians respectively - may have arisen from two biologically different populations. On the other hand, most DNA studies performed over extant and ancient populations suggest a single migration of a population from Northeast Asia. Comparing craniometric and mtDNA data of diachronic samples from East Central Argentina dated from 8,000 to 400 years BP, we show here that even when the oldest individuals display traits attributable to Paleoamerican crania, they present the same mtDNA haplogroups as later populations with Amerindian morphology. A possible explanation for these results could be that the craniofacial differentiation was a local phenomenon resulting from random (i.e. genetic drift) and non-random factors (e.g. selection and plasticity). Local processes of morphological differentiation in America are a probable scenario if we take into consideration the rapid peopling and the great ecological diversity of this continent; nevertheless we will discuss alternative explanations as well.Facultad de Ciencias Naturales y Muse

    “I wouldn’t know what to do with the breasts”: the impact of patient gender on medical student confidence and comfort in clinical skills

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    Background: Previous research has found a relationship between students’ gender and attitudes surrounding peer physical examination, but relationship between patient gender and confidence/comfort is less clear. We explored whether patient gender affects medical students’ levels of confidence and comfort in clinical examination skills. Methods: An electronic survey and focus groups were conducted with medical students from one UK institution. Students reported levels of confidence/comfort when carrying out clinical examinations on men/women. An inductive thematic analysis was performed. Results:    Of a total of 1500 students provided with the opportunity to participate, ninety (6%) responded. For cardiovascular and respiratory examinations, confidence/comfort were higher when examining male-presenting patients. The opposite was true for mental state examinations. Barriers to confidence/comfort included perceiving males as a norm, difficulty navigating breasts, tutors’ internalised gendered attitudes and a wider sociocultural issue. Facilitators of confidence/comfort included students relating to patients, embodying a professional role, gender blindness, and authentic clinical environments. Fewer than 20% (n = 18) of students felt they had enough opportunity to practice clinical skills on women, versus 90% (n = 82) on men. Conclusion: Our study identified an area where students’ confidence and comfort in clinical examinations could be enhanced within medical education. Changes were implemented in the institution under study’s vocational skills teaching, which is rooted in general practice. Information on gender and clinical skills was provided within course handbooks, time was scheduled to discuss gender and clinical skills in small group settings, and equitable gender representation was ensured in clinical assessment

    Lessons Learnt from Operationalising an International Collaborative Multi-Centre Study

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    Many medical students are both skilled and experienced in healthcare research, statistical analysis and evidence synthesis; assets that can be deployed to great effect in order to conduct research and contribute to the body of evidence - particularly in outbreak situations where senior doctors may be redeployed to clinical duties, thus ensuring that the next generation of academic clinicians’ interest and knowledge does not go in vain. Here, we document the process by which a group of medical students across the world, with senior support, harnessed their enthusiasm and the power of technology to play leading roles in an international multi-centre study run by the Global Health Research Group on Children’s Non-Communicable Diseases (Global Children’s NCDs). Many lessons have been learnt from the successful operationalisation of this study, which we hope to impart in this article. Our operations team consisted of: a social media team who manage our various accounts; a graphic design team who produce visuals to illustrate milestones achieved or highlight countries from which we did not yet have representatives; a network team who constructed a database to manage our extensive collaborator network; a communications team who managed emails and maintained regular contact with collaborators as well as producing a guide of common issues; a researcher support team who worked to ensure that any issues faced were dealt with promptly by hosting drop-in sessions; and finally a research capacity building team. We found that medical students bring fresh perspectives and an open-minded approach which is useful in reframing challenges and generating innovative solutions; thus it is vital to give them the opportunity to collaborate with, and learn from senior academics and policy-makers.&nbsp

    Discrepancy between cranial and DNA data of early Americans: Implications for American peopling

    Get PDF
    Currently, one of the major debates about the American peopling focuses on the number of populations that originated the biological diversity found in the continent during the Holocene. The studies of craniometric variation in American human remains dating from that period have shown morphological differences between the earliest settlers of the continent and some of the later Amerindian populations. This led some investigators to suggest that these groups - known as Paleomericans and Amerindians respectively - may have arisen from two biologically different populations. On the other hand, most DNA studies performed over extant and ancient populations suggest a single migration of a population from Northeast Asia. Comparing craniometric and mtDNA data of diachronic samples from East Central Argentina dated from 8,000 to 400 years BP, we show here that even when the oldest individuals display traits attributable to Paleoamerican crania, they present the same mtDNA haplogroups as later populations with Amerindian morphology. A possible explanation for these results could be that the craniofacial differentiation was a local phenomenon resulting from random (i.e. genetic drift) and non-random factors (e.g. selection and plasticity). Local processes of morphological differentiation in America are a probable scenario if we take into consideration the rapid peopling and the great ecological diversity of this continent; nevertheless we will discuss alternative explanations as well.Facultad de Ciencias Naturales y Muse

    An observational analysis of frailty in combination with loneliness or social isolation and their association with socioeconomic deprivation, hospitalisation and mortality among UK Biobank participants

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    Frailty, social isolation, and loneliness have individually been associated with adverse health outcomes. This study examines how frailty in combination with loneliness or social isolation is associated with socioeconomic deprivation and with all-cause mortality and hospitalisation rate in a middle-aged and older population. Baseline data from 461,047 UK Biobank participants (aged 37–73) were used to assess frailty (frailty phenotype), social isolation, and loneliness. Weibull models assessed the association between frailty in combination with loneliness or social isolation and all-cause mortality adjusted for age/sex/smoking/alcohol/socioeconomic-status and number of long-term conditions. Negative binomial regression models assessed hospitalisation rate. Frailty prevalence was 3.38%, loneliness 4.75% and social isolation 9.04%. Frailty was present across all ages and increased with age. Loneliness and social isolation were more common in younger participants compared to older. Co-occurrence of frailty and loneliness or social isolation was most common in participants with high socioeconomic deprivation. Frailty was associated with increased mortality and hospitalisation regardless of social isolation/loneliness. Hazard ratios for mortality were 2.47 (2.27–2.69) with social isolation and 2.17 (2.05–2.29) without social isolation, 2.14 (1.92–2.38) with loneliness and 2.16 (2.05–2.27) without loneliness. Loneliness and social isolation were associated with mortality and hospitalisation in robust participants, but this was attenuated in the context of frailty. Frailty and loneliness/social isolation affect individuals across a wide age spectrum and disproportionately co-occur in areas of high deprivation. All were associated with adverse outcomes, but the association between loneliness and social isolation and adverse outcomes was attenuated in the context of frailty. Future interventions should target people living with frailty or loneliness/social isolation, regardless of age

    The relationship between frailty and social vulnerability: a systematic review

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    Both frailty (reduced physiological reserve) and social vulnerability (scarcity of adequate social connections, support, or interaction) become more common as people age and are associated with adverse consequences. Analyses of the relationships between these constructs can be limited by the wide range of measures used to assess them. In this systematic review, we synthesised 130 observational studies assessing the association between frailty and social vulnerability, the bidirectional longitudinal relationships between constructs, and their joint associations with adverse health outcomes. Frailty, across assessment type, was associated with increased loneliness and social isolation, perceived inadequacy of social support, and reduced social participation. Each of these social vulnerability components was also associated with more rapid progression of frailty and lower odds of improvement compared with the absence of that social vulnerability component (eg, more rapid frailty progression in people with social isolation vs those who were not socially isolated). Combinations of frailty and social vulnerability were associated with increased mortality, decline in physical function, and cognitive impairment. Clinical and public health measures targeting frailty or social vulnerability should, therefore, account for both frailty and social vulnerability

    Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores

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    Funder: Funder: Fundación bancaria ‘La Caixa’ Number: LCF/PR/PR16/51110003 Funder: Grifols SA Number: LCF/PR/PR16/51110003 Funder: European Union/EFPIA Innovative Medicines Initiative Joint Number: 115975 Funder: JPco-fuND FP-829-029 Number: 733051061Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
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