34 research outputs found

    Beyond carbon: The contributions of South American tropical humid and subhumid forests to ecosystem services

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    Tropical forests are recognized for their role in providing diverse ecosystem services (ESs), with carbon uptake the best recognized. The capacity of tropical forests to provide ESs is strongly linked to their enormous biodiversity. However, causal relationships between biodiversity and ESs are poorly understood. This may be because biodiversity is often translated into species richness. Here we argue that focusing on multiple attributes of biodiversity—structure, composition, and function—will make relationships between biodiversity and ESs clearer. In this review, we discuss the ecological processes behind ESs from tropical humid and subhumid forests of South America. Our main goal is to understand the links between the ESs and those three biodiversity attributes. While supporting and regulating services relate more closely to forest structure and function, provisioning services relate more closely to forest composition and function, and cultural services are more related to structure and composition attributes. In this sense, ESs from subhumid forests (savannas) differ from those provided by the Amazon Forest, although both ecosystems are recognized as harboring tremendous biodiversity. Given this, if anthropogenic drivers of change promote a shift in the Amazon Forest toward savanna—the savannization hypothesis—the types of services provided will change, especially climate regulating services. This review emphasizes the importance of deeply understanding ecosystem structure, composition, and function to better understand the services ecosystems provide. Understanding that anthropogenic impacts on biodiversity occur through these three main attributes, it becomes easier to anticipate how humans will impact ESs

    Canine distemper virus induces apoptosis in cervical tumor derived cell lines

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    Apoptosis can be induced or inhibited by viral proteins, it can form part of the host defense against virus infection, or it can be a mechanism for viral spread to neighboring cells. Canine distemper virus (CDV) induces apoptotic cells in lymphoid tissues and in the cerebellum of dogs naturally infected. CDV also produces a cytopathologic effect, leading to apoptosis in Vero cells in tissue culture. We tested canine distemper virus, a member of the Paramyxoviridae family, for the ability to trigger apoptosis in HeLa cells, derived from cervical cancer cells resistant to apoptosis. To study the effect of CDV infection in HeLa cells, we examined apoptotic markers 24 h post infection (pi), by flow cytometry assay for DNA fragmentation, real-time PCR assay for caspase-3 and caspase-8 mRNA expression, and by caspase-3 and -8 immunocytochemistry. Flow cytometry showed that DNA fragmentation was induced in HeLa cells infected by CDV, and immunocytochemistry revealed a significant increase in the levels of the cleaved active form of caspase-3 protein, but did not show any difference in expression of caspase-8, indicating an intrinsic apoptotic pathway. Confirming this observation, expression of caspase-3 mRNA was higher in CDV infected HeLa cells than control cells; however, there was no statistically significant change in caspase-8 mRNA expression profile. Our data suggest that canine distemper virus induced apoptosis in HeLa cells, triggering apoptosis by the intrinsic pathway, with no participation of the initiator caspase -8 from the extrinsic pathway. In conclusion, the cellular stress caused by CDV infection of HeLa cells, leading to apoptosis, can be used as a tool in future research for cervical cancer treatment and control

    The effects of leaf traits on litter rainfall interception with consequences for runoff and soil conservation

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    During rainfall, plant litter interception regulates overland flow with an impact on water runoff generation and sediment displacement. Besides the rainfall characteristics, the effects of litter mass, thickness, storage and drainage properties on rainfall interception are reasonably well understood. In contrast, less is known about the influence of leaf traits, which we hypothesized to affect interception, soil hydrology and conservation via litter structure assembly. We measured the runoff and soil loss generation as determined by litter layer structural and hydraulic properties of 16 coexisting tropical woody species with wide-range morphological leaf traits in a rainfall simulator experiment. Our results show that litter produced by coexisting species can differ in precipitation interception, thereby influencing runoff and soil loss. This is because there is important interspecific variation in litter water storage and drainage, which are negatively affected by leaf area (LA). Leaf water repellency positively affected litter water storage. Moreover, LA also negatively affected litter layer density. Litter density, in turn, increased runoff, but decreased soil loss, possibly due to protection against splash erosion. These results can be used to predict the effects of plant traits on the soil water balance and soil integrity protection through ecohydrological interception by the litter layer. The next research steps will be to extend our model to multiple-species litter layers, and to validate and calibrate our model in different field situations in different ecosystems. Synthesis: We revealed the direct and indirect effects of species leaf size and hydraulic traits on litter rainfall interception, runoff and soil loss. We propose a new litter-soil ecohydrological model, by using structural equation models, which can be used as a tool to predict ecosystem functioning, and guide management and restoration actions with water and soil conservation targets

    Environment is more relevant than spatial structure as a driver of regional variation in tropical tree community richness and composition

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    <p><b>Background</b>: Understanding how factors related to environment and geographical distance explain community variation allows insights about how ecological niche and neutral processes control tropical community assembly.</p> <p><b>Aims</b>: Quantify how variation in regional tree community richness and composition in a humid tropical forest across a mountain chain are related to niche and putative neutral processes.</p> <p><b>Methods</b>: We used a variation partitioning routine based on Redundancy Analysis to model tropical tree community richness and composition within three distinct elevation belts, as a function of environment and spatial structure, using data from 32 studies in the Serra do Mar Range, south-eastern Brazil.</p> <p><b>Results</b>: Environmental effects were greater than spatial structure effects to explain community variation in the three elevation belts. There was a trend of decreasing spatial structure effects while environmental effects remained constant from lower to higher elevations. Patterns were congruent for species richness and composition.</p> <p><b>Conclusions</b>: We suggest that on tropical mountains, niche-related processes are equally relevant for tropical forest community assembly at all elevations, while neutral processes become weaker towards higher elevations. Determining if this trend is a consequence of the greater heterogeneity of environmental conditions associated with higher elevations in tropical mountainous terrain remains an important area of research.</p

    Diagnosis and clinic-pathological findings of influenza virus infection in Brazilian pigs Diagnóstico, achados clínicos e patológicos da infecção pelo vírus influenza em suínos no Brasil

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    Influenza A virus (IAV) is a respiratory pathogen of pigs and is associated with the porcine respiratory disease complex (PRDC), along with other respiratory infectious agents. The aim of this study was to diagnose and to perform a clinic-pathological characterization of influenza virus infection in Brazilian pigs. Lung samples from 86 pigs in 37 farrow-to-finish and two farrow-to-feeder operations located in the States of Minas Gerais, São Paulo, Paraná, Rio Grande do Sul, Santa Catarina, and Mato Grosso were studied. Virus detection was performed by virus isolation and quantitative real time reverse-transcription PCR (qRT-PCR). Pathologic examination and immunohistochemistry (IHC) were performed in 60 lung formalin-fixed paraffin-embedded tissue fragments. Affected animals showed coughing, sneezing, nasal discharge, hyperthermia, inactivity, apathy, anorexia, weight loss and growth delay, which lasted for five to 10 days. Influenza virus was isolated from 31 (36.0%) lung samples and 36 (41.9%) were positive for qRT-PCR. Thirty-eight (63.3%) lung samples were positive by IHC and the most frequent microscopic lesion observed was inflammatory infiltrate in the alveoli, bronchiole, or bronchi wall or lumen (76.7%). These results indicate that influenza virus is circulating and causing disease in pigs in several Brazilian states.<br>O vírus influenza A (IAV) é um patógeno respiratório comum de suínos e faz parte do complexo de doenças respiratórias do suíno (PRDC) junto com outros agentes infecciosos. O objetivo deste estudo foi diagnosticar e realizar a caracterização clínica e patológica de casos/surtos de influenza em suínos brasileiros. Foram utilizadas amostras de tecido pulmonar de 86 suínos de 37 granjas de ciclo completo e duas unidades produtoras de leitões localizadas em Minas Gerais, São Paulo, Paraná, Rio Grande do Sul, Santa Catarina e Mato Grosso. A detecção viral em fragmentos pulmonares frescos foi realizada através do isolamento viral e da transcrição reversa-PCR em tempo real quantitativa (qRT-PCR). Exame patológico e imuno-histoquímica (IHQ) foram realizados em 60 amostras de pulmão fixadas em formalina 10% e embebidas em parafina. As amostras eram de animais apresentando tosse, espirros, secreção nasal, hipertermia, prostração, apatia, anorexia, perda de peso e ganho de peso reduzido, com duração entre cinco e 10 dias. O vírus influenza foi isolado de 31 (36,0%) amostras e 36 (41,9%) foram positivas na qRT-PCR. Na IHQ, 38 (63,3%) amostras foram positivas e a lesão mais frequentemente observada foi a presença de infiltrado inflamatório na parede e lúmen de vias aéreas (76,7%). Estes resultados indicam que o vírus influenza está circulando e causando lesões e doença respiratória em suínos de diversos Estados do Brasil

    Diagnosis and clinic-pathological findings of influenza virus infection in Brazilian pigs

    No full text
    Influenza A virus (IAV) is a respiratory pathogen of pigs and is associated with the porcine respiratory disease complex (PRDC), along with other respiratory infectious agents. The aim of this study was to diagnose and to perform a clinic-pathological characterization of influenza virus infection in Brazilian pigs. Lung samples from 86 pigs in 37 farrow-to-finish and two farrow-to-feeder operations located in the States of Minas Gerais, São Paulo, Paraná, Rio Grande do Sul, Santa Catarina, and Mato Grosso were studied. Virus detection was performed by virus isolation and quantitative real time reverse-transcription PCR (qRT-PCR). Pathologic examination and immunohistochemistry (IHC) were performed in 60 lung formalin-fixed paraffin-embedded tissue fragments. Affected animals showed coughing, sneezing, nasal discharge, hyperthermia, inactivity, apathy, anorexia, weight loss and growth delay, which lasted for five to 10 days. Influenza virus was isolated from 31 (36.0%) lung samples and 36 (41.9%) were positive for qRT-PCR. Thirty-eight (63.3%) lung samples were positive by IHC and the most frequent microscopic lesion observed was inflammatory infiltrate in the alveoli, bronchiole, or bronchi wall or lumen (76.7%). These results indicate that influenza virus is circulating and causing disease in pigs in several Brazilian states

    Mobile applications as carriers of institutional pressures:a case of the Finnish taxi industry

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    Abstract While the worldwide market expansion of Uber has raised controversy, Uber has also received praise for its mobile phone app. Its many features — taxi ordering, pricing, real-time location information, paying, and service evaluation — have provided significant customer value. When Uber entered Finland in November 2014, few other taxi apps were available. Between 2014 and 2018, this shortage of taxi apps turned into an abundance, with many companies introducing their own taxi apps. By leaning on institutional theory, and more specifically by applying coercive, mimetic and normative pressures as a lens, we provide an explanation for why three Finnish taxi apps now resemble Uber in some features, whereas they differ in others. Based on our interviews, we can explain the present-day differences between these apps by coercive and normative pressures in the institutional environment of the Finnish taxi industry. We contribute to the IT and institutionalization research stream by illustrating how mobile applications as IT artefacts can be seen as carriers of institutional pressures materializing in the features they provide
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