62 research outputs found
Comparing tropical forest tree size distributions with the predictions of metabolic ecology and equilibrium models
Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing censuses of 473 ha and \u3e 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality. © 2006 Blackwell Publishing Ltd/CNRS
Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests
The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and
mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into
the global carbon budget, and deserves careful assessment. We assembled data from 10 old-growth tropical forests encompassing
censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions
that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes
with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical
forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it,
and were inconsistent with the predictions of metabolic ecology in all forests
CONSENSO SOBRE EL USO DE PROTEÍNA EN EL PACIENTE CRÍTICO – ACNC
El paciente crítico tiene una pérdida de masa muscular significativa, observando frecuentemente sarcopenia en estos pacientes. Su presencia aumenta los desenlaces adversos, estancias hospitalarias, mayor riesgo de infecciones, aumento del tiempo de asistencia ventilatoria mecánica, mayor discapacidad al alta hospitalaria, menor posibilidad del retorno normal a la vida habitual de los pacientes, incremento en gastos en salud y mayor mortalidad. Objetivo: Indicar el uso oportuno y adecuado de la proteína en el paciente crítico. Métodos: la Asociación Colombiana De Nutrición Clínica (ACNC) y la Asociación Colombiana de Medicina Critica y Cuidados Intensivos (AMCI) mediante metodología de consenso realizaron unas recomendaciones con un grupo de expertos. Resultados: 46 recomendaciones fueron aprobadas con consenso superior al 80%. Conclusiones: La intervención óptima proteica temprana y progresiva en el paciente crítico, es importante para obtener los mejores desenlaces clínicos, disminuir complicaciones e impactar en costos de atención hospitalaria.
CONSENSO SOBRE O USO DE PROTEÍNA EM PACIENTES CRÍTICOS – ACNC
The critical patient has a significant loss of muscle mass, frequently observing sarcopenia in these patients. Its presence increases adverse outcomes, hospital stays, increased risk of infections, increased time on mechanical ventilatory assistance, greater disability at hospital discharge, less possibility of return to normal life for patients, increased health costs, and higher mortality. Objective: Indicate the opportune and adequate use of the protein in the critically ill patient. Methods: the Colombian Association of Clinical Nutrition (ACNC) and the Colombian Association of Critical Medicine and Intensive Care (AMCI), using a consensus methodology, made recommendations with a group of experts. Results: 46 recommendations were approved with a consensus greater than 80%. Conclusions: Optimal early and progressive protein intervention in critically ill patients is important to obtain the best clinical outcomes, reduce complications, and have an impact on hospital care costs.El paciente crítico tiene una pérdida de masa muscular significativa, observando frecuentemente sarcopenia en estos pacientes. Su presencia aumenta los desenlaces adversos, estancias hospitalarias, mayor riesgo de infecciones, aumento del tiempo de asistencia ventilatoria mecánica, mayor discapacidad al alta hospitalaria, menor posibilidad del retorno normal a la vida habitual de los pacientes, incremento en gastos en salud y mayor mortalidad. Objetivo: Indicar el uso oportuno y adecuado de la proteína en el paciente crítico. Métodos: la Asociación Colombiana De Nutrición Clínica (ACNC) y la Asociación Colombiana de Medicina Critica y Cuidados Intensivos (AMCI) mediante metodología de consenso realizaron unas recomendaciones con un grupo de expertos. Resultados: 46 recomendaciones fueron aprobadas con consenso superior al 80%. Conclusiones: La intervención óptima proteica temprana y progresiva en el paciente crítico, es importante para obtener los mejores desenlaces clínicos, disminuir complicaciones e impactar en costos de atención hospitalaria. O paciente crítico apresenta perda importante de massa muscular, observando-se frequentemente sarcopenia nesses pacientes. Sua presença aumenta os desfechos adversos, internações hospitalares, aumento do risco de infecções, aumento do tempo de assistência ventilatória mecânica, maior incapacidade na alta hospitalar, menor possibilidade de retorno à vida normal dos pacientes, aumento dos custos de saúde e maior mortalidade. Objetivo: Indicar o uso oportuno e adequado da proteína no paciente crítico. Métodos: a Associação Colombiana de Nutrição Clínica (ACNC) e a Associação Colombiana de Medicina Crítica e Terapia Intensiva (AMCI), utilizando uma metodologia de consenso, fizeram recomendações com um grupo de especialistas. Resultados: 46 recomendações foram aprovadas com consenso superior a 80%. Conclusões: A intervenção proteica precoce e progressiva ideal em pacientes críticos é importante para obter os melhores resultados clínicos, reduzir complicações e impactar nos custos hospitalares
Towards precision medicine: defining and characterizing adipose tissue dysfunction to identify early immunometabolic risk in symptom-free adults from the GEMM family study
Interactions between macrophages and adipocytes are early molecular factors influencing adipose tissue (AT) dysfunction, resulting in high leptin, low adiponectin circulating levels and low-grade metaflammation, leading to insulin resistance (IR) with increased cardiovascular risk. We report the characterization of AT dysfunction through measurements of the adiponectin/leptin ratio (ALR), the adipo-insulin resistance index (Adipo-IRi), fasting/postprandial (F/P) immunometabolic phenotyping and direct F/P differential gene expression in AT biopsies obtained from symptom-free adults from the GEMM family study. AT dysfunction was evaluated through associations of the ALR with F/P insulin-glucose axis, lipid-lipoprotein metabolism, and inflammatory markers. A relevant pattern of negative associations between decreased ALR and markers of systemic low-grade metaflammation, HOMA, and postprandial cardiovascular risk hyperinsulinemic, triglyceride and GLP-1 curves was found. We also analysed their plasma non-coding microRNAs and shotgun lipidomics profiles finding trends that may reflect a pattern of adipose tissue dysfunction in the fed and fasted state. Direct gene differential expression data showed initial patterns of AT molecular signatures of key immunometabolic genes involved in AT expansion, angiogenic remodelling and immune cell migration. These data reinforce the central, early role of AT dysfunction at the molecular and systemic level in the pathogenesis of IR and immunometabolic disorders
Polygenic Risk Scores for Prediction of Breast Cancer and Breast Cancer Subtypes
Stratification of women according to their risk of breast cancer based on polygenic risk scores (PRSs) could improve screening and prevention strategies. Our aim was to develop PRSs, optimized for prediction of estrogen receptor (ER)-specific disease, from the largest available genome-wide association dataset and to empirically validate the PRSs in prospective studies. The development dataset comprised 94,075 case subjects and 75,017 control subjects of European ancestry from 69 studies, divided into training and validation sets. Samples were genotyped using genome-wide arrays, and single-nucleotide polymorphisms (SNPs) were selected by stepwise regression or lasso penalized regression. The best performing PRSs were validated in an independent test set comprising 11,428 case subjects and 18,323 control subjects from 10 prospective studies and 190,040 women from UK Biobank (3,215 incident breast cancers). For the best PRSs (313 SNPs), the odds ratio for overall disease per 1 standard deviation in ten prospective studies was 1.61 (95%CI: 1.57-1.65) with area under receiver-operator curve (AUC) = 0.630 (95%CI: 0.628-0.651). The lifetime risk of overall breast cancer in the top centile of the PRSs was 32.6%. Compared with women in the middle quintile, those in the highest 1% of risk had 4.37- and 2.78-fold risks, and those in the lowest 1% of risk had 0.16- and 0.27-fold risks, of developing ER-positive and ER-negative disease, respectively. Goodness-of-fit tests indicated that this PRS was well calibrated and predicts disease risk accurately in the tails of the distribution. This PRS is a powerful and reliable predictor of breast cancer risk that may improve breast cancer prevention programs.NovartisEli Lilly and CompanyAstraZenecaAbbViePfizer UKCelgeneEisaiGenentechMerck Sharp and DohmeRocheCancer Research UKGovernment of CanadaArray BioPharmaGenome CanadaNational Institutes of HealthEuropean CommissionMinistère de l'Économie, de l’Innovation et des Exportations du QuébecSeventh Framework ProgrammeCanadian Institutes of Health Researc
Copernicus Ocean State Report, issue 6
The 6th issue of the Copernicus OSR incorporates a large range of topics for the blue, white and green ocean for all European regional seas, and the global ocean over 1993–2020 with a special focus on 2020
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Malaria vector species in Colombia: a review
Here we present a comprehensive review of the literature on the vectorial importance of the major Anopheles malaria vectors in Colombia. We provide basic information on the geographical distribution, altitudinal range, immature habitats, adult behaviour, feeding preferences and anthropophily, endophily and infectivity rates. We additionally review information on the life cycle, longevity and population fluctuation of Colombian Anopheles species. Emphasis was placed on the primary vectors that have been epidemiologically incriminated in malaria transmission: Anopheles darlingi, Anopheles albimanus and Anopheles nuneztovari. The role of a selection of local, regional or secondary vectors (e.g., Anopheles pseudopunctipennis and Anopheles neivai) is also discussed. We highlight the importance of combining biological, morphological and molecular data for the correct taxonomical determination of a given species, particularly for members of the species complexes. We likewise emphasise the importance of studying the bionomics of primary and secondary vectors along with an examination of the local conditions affecting the transmission of malaria. The presence and spread of the major vectors and the emergence of secondary species capable of transmitting human Plasmodia are of great interest. When selecting control measures, the anopheline diversity in the region must be considered. Variation in macroclimate conditions over a species' geographical range must be well understood and targeted to plan effective control measures based on the population dynamics of the local Anopheles species
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