50 research outputs found

    Disturbance and Clonal Reproduction Determine Liana Distribution and Maintain Liana Diversity in a Tropical Forest

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    Negative density dependence (NDD) and habitat specialization have received strong empirical support as mechanisms that explain tree species diversity maintenance and distribution in tropical forests. In contrast, disturbance appears to play only a minor role. Previous studies have rarely examined the relative strengths of these diversity maintenance mechanisms concurrently, and few studies have included plant groups other than trees. Here we used a large, spatially explicit data set from Barro Colorado Island, Panama (BCI) to test whether liana and tree species distribution patterns are most consistent with NDD, habitat specialization, or disturbance. We found compelling evidence that trees responded to habitat specialization and NDD; however, only disturbance explained the distribution of the majority of liana species and maintained liana diversity. Lianas appear to respond to disturbance with high vegetative (clonal) reproduction, and liana species\u27 ability to produce clonal stems following disturbance results in a clumped spatial distribution. Thus, clonal reproduction following disturbance explains local liana spatial distribution and diversity maintenance on BCI, whereas negative density dependence and habitat specialization, two prominent mechanisms contributing to tree species diversity and distribution, do not

    Nature and Age of Neighbours Matter : Interspecific Associations among Tree Species Exist and Vary across Life Stages in Tropical Forests

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    Data Availability: All relevant data are within the paper and its Supporting Information files. Funding: This research was funded through a PhD grant from the Universidad Politécnica de Madrid, and support of a FP7-PEOPLE-2013-IEF Marie-Curie Action.Peer reviewedPublisher PD

    Evaluación de la respuesta terapéutica en pacientes con enfermedad artrósica por farmacéuticos comunitarios

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    Introducción: La artrosis es una enfermedad que origina dolor, rigidez e incapacidad funcional. Actualmente el tratamiento es sintomático, no existen fármacos con capacidad para frenar la enfermedad artrósica, aunque los síntomas que origina se pueden aliviar, permitiendo que el paciente padezca lo menos posible.Objetivos: Evaluar la respuesta terapéutica en pacientes con osteoartrosis desde la farmacia comunitaria.Material y métodos: Estudio cuasi experimental no aleatorizado realizado en farmacias comunitarias de Madrid. Se cumplimentó un cuestionario estructurado recogiendo información sobre el paciente, diagnóstico, medicamentos prescritos, articulaciones afectadas, grado de dolor, estado funcional de la articulación, estado global del paciente e intervención farmacéutica realizada.Resultados: La muestra fue constituida por 141pacientes. Los fármacos incluidos pertenecieron a los grupos N02B (36,1 %), M01A (27,6 %), N02AX (23,4 %), M01AH (14,1 %), M01AX (27,6 %) prescritos para osteoartrosis. Con relación al dolor, 34 (24,1 %) pacientes obtuvieron una reducción del dolor de 20 mm en la EVA, alcanzando la respuesta clínica mínima efectiva. Respecto a la calidad de vida, la actividad más afectada fue la de subir y bajar escaleras, presentado muchísimo dolor al subir y bajar escaleras 58 (41,1 %) sujetos. Detectamos 111 RNM, de los que 61 fueron de inefectividad (54,9 %). La intervención farmacéutica fue ofrecer educación sanitaria en el autocuidado de las articulaciones a 29 (20,5 %) pacientes, recomendar ejercicio físico a 32 (22,7 %), recomendar dieta-ejercicio a 23 (16,3 %), derivar al especialista a 19 (13,4 %), derivar al MAP a 12 (8,5 %).Conclusión: La intervención del farmacéutico comunitario en pacientes con osteoartrosis contribuye a mejorar la efectividad de los tratamientos, mejorando los resultados de salud de los mismos

    Re-evaluation of individual diameter : height allometric models to improve biomass estimation of tropical trees

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    The first author was supported by the European Union under a IEF Marie-Curie Action.Accurate estimation of tree biomass is necessary to provide realistic values of the carbon stored in the terrestrial biosphere. A recognized source of errors in tree above-ground biomass (AGB) estimation is introduced when individual tree height values (H) are not directly measured but estimated from diameter at breast height (DBH) using allometric equations. In this paper we evaluate the performance of 12 alternative DBH : H equations and compare their effects on AGB estimation for three tropical forests that occur in contrasting climatic and altitudinal zones. We found that fitting a 3-parameter Weibull function using data collected locally generated the lowest errors and bias in H estimation, and that equations fitted to these data were more accurate than equations with parameters derived from the literature. For computing AGB, the introduced error values differed notably among DBH : H allometric equations, and in most cases showed a clear bias that resulted in either over- or under-estimation of AGB. Fitting the three-parameter Weibull function minimized errors in AGB estimates in our study and we recommend its widespread adoption for carbon stock estimation. We conclude that many previous studies are likely to present biased estimates of AGB due to the method of H estimation.Publisher PDFPeer reviewe

    Micro-scale habitat associations of woody plants in a neotropical cloud forest

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    Species?habitat associations may contribute to the maintenance of species richness in tropical forests, but previous research has been conducted almost exclusively in lowland forests and has emphasized the importance of topography and edaphic conditions. Is the distribution of woody plant species in a Peruvian cloud forest determined by microhabitat conditions? What is the role of environmental characteristics and forest structure in habitat partitioning in a tropical cloud forest? We examined species?habitat associations in three 1-ha plots using the torus-translation method. We used three different criteria to define habitats for habitat partitioning analyses, based on microtopography, forest structure and both sets of factors. The number of species associated either positively or negatively with each habitat was assessed. Habitats defined on the basis of environmental conditions and forest structure discriminated a greater number of positive and negative associations at the scale of our analyses in a tropical cloud forest. Both topographic conditions and forest structure contribute to small-scale microhabitat partitioning of woody plant species in a Peruvian tropical cloud forest. Nevertheless, canopy species were most correlated with the distribution of environmental variables, while understorey species displayed associations with forest structure

    Evaluation of four modelling approaches to estimate nitrous oxide emissions in China’s cropland

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    This work was financially supported by China Natural Science Foundation under a grant number 41501569 and “the Fundamental Research Funds for the Central Universities” under a grant number KJQN201673. This work was also supported by Department of Science and Technology of Jiangsu province under a grant number BK20150684. This work also contributes to the activities of NCircle - a BBSRC-Newton Funded project (BB/N013484/1). The first author thanks the China Scholarship Council (CSC) for funding to support study at University of Aberdeen, UK.Peer reviewedPostprin

    Trade-offs among aboveground, belowground, and soil organic carbon stocks along altitudinal gradients in Andean tropical montane forests

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    Tropical montane forests (TMFs) play an important role as a carbon reservoir at a global scale. However, there is a lack of a comprehensive understanding on the variation in carbon storage across TMF compartments [namely aboveground biomass (AGB), belowground biomass (BGB), and soil organic matter] along altitudinal and environmental gradients and their potential trade-offs. This study aims to: 1) understand how carbon stocks vary along altitudinal gradients in Andean TMFs, and; 2) determine the influence of climate, particularly precipitation seasonality, on the distribution of carbon stocks across different forest compartments. The study was conducted in sixty 0.1 ha plots along two altitudinal gradients at the Podocarpus National Park (Ecuador) and Río Abiseo National Park (Peru). At each plot, we calculated the amount of carbon in AGB (i.e. aboveground carbon stock, AGC), BGB (i.e. belowground carbon stock, BGC), and soil organic matter (i.e. soil organic carbon stock, SOC). The mean total carbon stock was 244.76 ± 80.38 Mg ha–1 and 211.51 ± 46.95 Mg ha–1 in the Ecuadorian and Peruvian plots, respectively. Although AGC, BGC, and SOC showed different partitioning patterns along the altitudinal gradient both in Ecuador and Peru, total carbon stock did not change with altitude in either site. The combination of annual mean temperature and precipitation seasonality explained differences in the observed patterns of carbon stocks across forest compartments between the two sites. This study suggests that the greater precipitation seasonality of colder, higher altitudes may promote faster turnover rates of organic matter and nutrients and, consequently, less accumulation of SOC but greater AGC and BGC, compared to those sites with lesser precipitation seasonality. Our results demonstrate the capacity of TMFs to store substantial amounts of carbon and suggest the existence of a trade-off in carbon stocks among forest compartments, which could be partly driven by differences in precipitation seasonality, especially under the colder temperatures of high altitudesAuthorizations to work in protected areas were granted by national authorities: Ecuador (MAE-DNB-CM2015-0016) and Perú (001-2016-SERNANP-PNRA-JEF

    A Large Case-Control Study Performed in Spanish Population Suggests That RECQL5 Is the Only RECQ Helicase Involved in Breast Cancer Susceptibility.

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    Around 50% of the familial breast cancer (BC) cases are estimated to be caused by germline variants in known low-, moderate-, and high-risk susceptibility genes, while the other half is of unknown genetic origin. In the present study, we wanted to evaluate the role of the RECQ helicases, some of which have been studied in the past as candidates, with unclear results about their role in the disease. Using next-generation sequencing (NGS) technology, we analyzed the whole coding sequence of BLM, RECQL1, RECQL4, RECQL5, and WRN in almost 2000 index cases from BC Spanish families that had previously tested negative for the known BC susceptibility genes (BRCAX) and compared the results with the controls extracted from gnomAD. Our results suggest that BLM, RECQL1, RECQL4, and WRN do not play a major role in BC susceptibility. However, in the combined analysis, joining the present results with those previously reported in a series of 1334 BC Spanish patients and controls, we found a statistically significant association between Loss of Function (LoF) variants in RECQL5 and BC risk, with an OR of 2.56 (p = 0.009; 95% CI, 1.18-4.98). Our findings support our previous work and places the RECQL5 gene as a new moderate-risk BC gene.A.O. is partially funded by FIS PI19/00640 supported by FEDER funds and the Spanish Network on Rare Diseases (CIBERER). M.d.l.H. is partially funded by FIS PI20/00110 supported by FEDER funds.S

    Liana Abundance, Diversity, and Distribution on Barro Colorado Island, Panama

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    Lianas are a key component of tropical forests; however, most surveys are too small to accurately quantify liana community composition, diversity, abundance, and spatial distribution – critical components for measuring the contribution of lianas to forest processes. In 2007, we tagged, mapped, measured the diameter, and identified all lianas ≥1 cm rooted in a 50-ha plot on Barro Colorado Island, Panama (BCI). We calculated liana density, basal area, and species richness for both independently rooted lianas and all rooted liana stems (genets plus clones). We compared spatial aggregation patterns of liana and tree species, and among liana species that varied in the amount of clonal reproduction. We also tested whether liana and tree densities have increased on BCI compared to surveys conducted 30-years earlier. This study represents the most comprehensive spatially contiguous sampling of lianas ever conducted and, over the 50 ha area, we found 67,447 rooted liana stems comprising 162 species. Rooted lianas composed nearly 25% of the woody stems (trees and lianas), 35% of woody species richness, and 3% of woody basal area. Lianas were spatially aggregated within the 50-ha plot and the liana species with the highest proportion of clonal stems more spatially aggregated than the least clonal species, possibly indicating clonal stem recruitment following canopy disturbance. Over the past 30 years, liana density increased by 75% for stems ≥1 cm diameter and nearly 140% for stems ≥5 cm diameter, while tree density on BCI decreased 11.5%; a finding consistent with other neotropical forests. Our data confirm that lianas contribute substantially to tropical forest stem density and diversity, they have highly clumped distributions that appear to be driven by clonal stem recruitment into treefall gaps, and they are increasing relative to trees, thus indicating that lianas will play a greater role in the future dynamics of BCI and other neotropical forests

    Coortes no Brasil com potencial para estudos do ciclo vital: uma revisão de escopo

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    OBJECTIVE: To identify the Brazilian cohorts that started either in the prenatal period or at birth, to describe their characteristics and the explored variables, and to map the cohorts with potential for studies on early determinants on health and the risk of falling ill on later stages of the life cycle. METHODS: A scoping review was carried out. The articles were searched in the electronic databases PubMed and Virtual Health Library (VHL). The descriptors used were [(((“Child” OR “Child, Preschool” OR “Infant” OR “Infant, Newborn”) AND (Cohort Studies” OR “Longitudinal Studies”)) AND “Brazil”)]. The inclusion criteria were Brazilian cohorts that started the baseline in the prenatal period or at birth and with at least two follow-ups with the participants. In order to meet the concept of LCE, we excluded those cohorts whose follow-ups were restricted to the first year of life, as well as those that did not address biological, behavioral and psychosocial aspects, and cohorts with data collection of a single stage of the life cycle. RESULTS: The search step identified 5,010 articles. Eighteen cohorts were selected for descriptive synthesis. The median number of baseline participants was 2,000 individuals and the median age at the last follow-up was 9 years. Sample loss at the last follow-up ranged from 9.2 to 87.5%. Most cohorts monitored two phases of the life cycle (the perinatal period and childhood). The Southern region had the highest number of cohorts. The main variables collected were sociodemographic and environmental aspects of the family, morbidity aspects, nutritional practices and lifestyle. CONCLUSIONS: We recommend the continuity of these cohorts, the approach to different social contexts and the performance of follow-ups with participants in different phases of the life cycle for the strengthening and expansion of life course epidemiology analyses in Brazil.OBJETIVO: Identificar as coortes brasileiras iniciadas no período pré-natal ou no nascimento, descrever suas características e as variáveis exploradas, além de mapear as coortes com potencial para se estudar os determinantes precoces de saúde e doença e o risco de adoecer em etapas posteriores do ciclo vital. MÉTODOS: Realizou-se uma revisão de escopo. A busca dos artigos foi realizada nas bases de dados PubMed e Biblioteca Virtual em Saúde em 16 de junho de 2018. Os descritores utilizados foram [(((“Child” OR “Child, Preschool” OR “Infant” OR “Infant, Newborn”) AND (“Cohort Studies” OR “Longitudinal Studies”)) AND “Brazil”)]. Os critérios de inclusão foram coortes brasileiras que iniciaram a linha de base no período pré-natal ou no nascimento e com pelo menos dois acompanhamentos com os participantes. Foram excluídas as coortes cujos acompanhamentos foram restritos ao primeiro ano de vida, as que não abordaram aspectos biológicos, comportamentais e psicossociais e também aquelas com coleta de informações em um único estágio do ciclo vital. RESULTADOS: A etapa de busca identificou 5.010 artigos. Foram selecionadas 18 coortes para a síntese descritiva. A mediana do número de participantes na linha de base foi 2.000 indivíduos e a mediana de idade no último acompanhamento foi 9 anos. A perda amostral no último acompanhamento variou de 9,2 a 87,5%. A maioria das coortes realizou acompanhamentos em duas fases do ciclo vital (período perinatal e infância). A região Sul contemplou o maior número de coortes. As principais variáveis coletadas foram sociodemográficas e ambientais da família, aspectos de morbidade, práticas alimentares e estilo de vida dos participantes. CONCLUSÕES: Recomenda-se a continuidade dessas coortes, a abordagem de diferentes contextos sociais e a realização de acompanhamentos com os participantes em diferentes fases do ciclo vital para o fortalecimento e ampliação das análises de epidemiologia do ciclo vital no Brasil
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