36 research outputs found
Arthropod distribution in a tropical rainforest: tackling a four dimensional puzzle
Quantifying the spatio-temporal distribution of arthropods in tropical rainforests represents
a first step towards scrutinizing the global distribution of biodiversity on Earth. To date moststudies have focused on narrow taxonomic groups or lack a design that allows partitioning
of the components of diversity. Here, we consider an exceptionally large dataset (113,952
individuals representing 5,858 species), obtained from the San Lorenzo forest in Panama,
where the phylogenetic breadth of arthropod taxa was surveyed using 14 protocols targeting
the soil, litter, understory, lower and upper canopy habitats, replicated across seasons
in 2003 and 2004. This dataset is used to explore the relative influence of horizontal, vertical
and seasonal drivers of arthropod distribution in this forest. We considered arthropod abundance,
observed and estimated species richness, additive decomposition of species richness,
multiplicative partitioning of species diversity, variation in species composition,
species turnover and guild structure as components of diversity. At the scale of our study
(2km of distance, 40m in height and 400 days), the effects related to the vertical and seasonal
dimensions were most important. Most adult arthropods were collected from the soil/
litter or the upper canopy and species richness was highest in the canopy. We compared
the distribution of arthropods and trees within our study system. Effects related to the seasonal
dimension were stronger for arthropods than for trees. We conclude that: (1) models
of beta diversity developed for tropical trees are unlikely to be applicable to tropical arthropods;
(2) it is imperative that estimates of global biodiversity derived from mass collecting of
arthropods in tropical rainforests embrace the strong vertical and seasonal partitioning
observed here; and (3) given the high species turnover observed between seasons, global
climate change may have severe consequences for rainforest arthropods
Arthropod distribution in a tropical rainforest: tackling a four dimensional puzzle
Quantifying the spatio-temporal distribution of arthropods in tropical rainforests represents a first step towards scrutinizing the global distribution of biodiversity on Earth. To date most studies have focused on narrow taxonomic groups or lack a design that allows partitioning of the components of diversity. Here, we consider an exceptionally large dataset (113,952 individuals representing 5,858 species), obtained from the San Lorenzo forest in Panama, where the phylogenetic breadth of arthropod taxa was surveyed using 14 protocols targeting the soil, litter, understory, lower and upper canopy habitats, replicated across seasons in 2003 and 2004. This dataset is used to explore the relative influence of horizontal, vertical and seasonal drivers of arthropod distribution in this forest. We considered arthropod abundance, observed and estimated species richness, additive decomposition of species richness, multiplicative partitioning of species diversity, variation in species composition, species turnover and guild structure as components of diversity. At the scale of our study (2km of distance, 40m in height and 400 days), the effects related to the vertical and seasonal dimensions were most important. Most adult arthropods were collected from the soil/litter or the upper canopy and species richness was highest in the canopy. We compared the distribution of arthropods and trees within our study system. Effects related to the seasonal dimension were stronger for arthropods than for trees. We conclude that: (1) models of beta diversity developed for tropical trees are unlikely to be applicable to tropical arthropods; (2) it is imperative that estimates of global biodiversity derived from mass collecting of arthropods in tropical rainforests embrace the strong vertical and seasonal partitioning observed here; and (3) given the high species turnover observed between seasons, global climate change may have severe consequences for rainforest arthropods1012CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSolVin-Solvay SA; Smithsonian Institution; Smithsonian Tropical Research Institute; United Nations Environment Programme; Smithsonian Institution; Smithsonian National Museum of Natural History; European Science Foundation (ESF); Global Canopy Programme; Czech Science foundation GACR grant; European Social Fund (ESF); Ministry of Education, Youth & Sports - Czech Republic; French National Research Agency (ANR); Research Council of Norway; Grant Agency of the Czech Republi
Looking the Part: Social Status Cues Shape Race Perception
It is commonly believed that race is perceived through another's facial features, such as skin color. In the present research, we demonstrate that cues to social status that often surround a face systematically change the perception of its race. Participants categorized the race of faces that varied along White–Black morph continua and that were presented with high-status or low-status attire. Low-status attire increased the likelihood of categorization as Black, whereas high-status attire increased the likelihood of categorization as White; and this influence grew stronger as race became more ambiguous (Experiment 1). When faces with high-status attire were categorized as Black or faces with low-status attire were categorized as White, participants' hand movements nevertheless revealed a simultaneous attraction to select the other race-category response (stereotypically tied to the status cue) before arriving at a final categorization. Further, this attraction effect grew as race became more ambiguous (Experiment 2). Computational simulations then demonstrated that these effects may be accounted for by a neurally plausible person categorization system, in which contextual cues come to trigger stereotypes that in turn influence race perception. Together, the findings show how stereotypes interact with physical cues to shape person categorization, and suggest that social and contextual factors guide the perception of race
Trf4 targets ncRNAs from telomeric and rDNA spacer regions and functions in rDNA copy number control
Trf4 is the poly(A) polymerase component of TRAMP4, which stimulates nuclear RNA degradation by the exosome. We report that in Saccharomyces cerevisiae strains lacking Trf4, cryptic transcripts are detected from regions of repressed chromatin at telomeres and the rDNA intergenic spacer region (IGS1-R), and at CEN3. Degradation of the IGS1-R transcript was reduced in strains lacking TRAMP components, the core exosome protein Mtr3 or the nuclear-specific exosome component Rrp6. IGS1-R has potential binding sites for the RNA-binding proteins Nrd1/Nab3, and was stabilized by mutation of Nrd1. IGS1-R passes through the replication fork barrier, a region required for rDNA copy number control. Strains lacking Trf4 showed sporadic changes in rDNA copy number, whereas loss of both Trf4 and either the histone deacetylase Sir2 or the topoisomerase Top1 caused dramatic loss of rDNA repeats. Chromatin immunoprecipitation analyses showed that Trf4 is co-transcriptionally recruited to IGS1-R, consistent with a direct role in rDNA stability. Co-transcriptional RNA binding by Trf4 may link RNA and DNA metabolism and direct immediate IGS1-R degradation by the exosome following transcription termination
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
Variation in general supportive and preventive intensive care management of traumatic brain injury: a survey in 66 neurotrauma centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study
Abstract
Background
General supportive and preventive measures in the intensive care management of traumatic brain injury (TBI) aim to prevent or limit secondary brain injury and optimize recovery. The aim of this survey was to assess and quantify variation in perceptions on intensive care unit (ICU) management of patients with TBI in European neurotrauma centers.
Methods
We performed a survey as part of the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. We analyzed 23 questions focused on: 1) circulatory and respiratory management; 2) fever control; 3) use of corticosteroids; 4) nutrition and glucose management; and 5) seizure prophylaxis and treatment.
Results
The survey was completed predominantly by intensivists (n = 33, 50%) and neurosurgeons (n = 23, 35%) from 66 centers (97% response rate).
The most common cerebral perfusion pressure (CPP) target was > 60 mmHg (n = 39, 60%) and/or an individualized target (n = 25, 38%). To support CPP, crystalloid fluid loading (n = 60, 91%) was generally preferred over albumin (n = 15, 23%), and vasopressors (n = 63, 96%) over inotropes (n = 29, 44%). The most commonly reported target of partial pressure of carbon dioxide in arterial blood (PaCO2) was 36–40 mmHg (4.8–5.3 kPa) in case of controlled intracranial pressure (ICP) < 20 mmHg (n = 45, 69%) and PaCO2 target of 30–35 mmHg (4–4.7 kPa) in case of raised ICP (n = 40, 62%). Almost all respondents indicated to generally treat fever (n = 65, 98%) with paracetamol (n = 61, 92%) and/or external cooling (n = 49, 74%). Conventional glucose management (n = 43, 66%) was preferred over tight glycemic control (n = 18, 28%). More than half of the respondents indicated to aim for full caloric replacement within 7 days (n = 43, 66%) using enteral nutrition (n = 60, 92%). Indications for and duration of seizure prophylaxis varied, and levetiracetam was mostly reported as the agent of choice for both seizure prophylaxis (n = 32, 49%) and treatment (n = 40, 61%).
Conclusions
Practice preferences vary substantially regarding general supportive and preventive measures in TBI patients at ICUs of European neurotrauma centers. These results provide an opportunity for future comparative effectiveness research, since a more evidence-based uniformity in good practices in general ICU management could have a major impact on TBI outcome
Programas de microfinanzas y mejoras estructurales en los hogares: evaluación de impacto utilizando propensity score matching
El presente estudio se propone examinar los efectos de las microfinanzas sobre las condiciones de infraestructura de los hogares de quienes toman microcréditos, tomando como base del trabajo un relevamiento realizado en el municipio de Moreno, en el conurbano de la Provincia de Buenos Aires. Para este trabajo se tomaron en cuenta las dificultades técnicas de auto-selección y endogeneidad. Se realizaron diferentes correcciones para confeccionar un grupo comparable adecuado y se optó por el método denominado Propensity Score Matching para estimar el efecto promedio del programa. Los resultados obtenidos muestran que las personas que participaron de los programas de microfinanzas realizaron un número mayor de reformas en el hogar que los no tratados. En particular, se realizaron mediciones sobre las reformas por año, las cuales arrojaron datos positivos sobre el impacto del programa. De igual modo se realizaron contrastes por tipo de reformas, las cuales mostraron que los tratados realizaron mayores reformas en aspectos críticos de la vivienda (cimiento, techo, instalación sanitaria, etc.) respecto a los no tratados.Esta tesis en PDF no tiene permisos por parte del autor para ser reproducida. Puedes venir a
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The Role of Fine-Needle Aspiration in Parotid Pleomorphic Adenoma
Objective: Fine-needle aspiration (FNA) biopsy is often used as a well-accepted and both sensitive and specific diagnostic adjunct in the workup of parotid masses. In the case of pleomorphic adenoma, the most common benign tumor of the parotid gland, we examine cytopathologic reports to assess the performance of FNA for this particular histologic diagnosis. Method: A total of 317 patients who underwent parotidectomy over the past 5 years and met eligibility criteria of 1) primary parotid tumor, 2) age greater than 18 years, and 3) availability of pathology (FNA, intraoperative frozen section, final pathology) were reviewed. Clinical history and demographics, physical exam findings, and intraoperative findings were noted. Results: Pleomorphic adenoma was noted on final pathology in 136 patients (42.9%). Interestingly 24 (17.6%) of these patients had initially undergone FNA and been given a incorrect diagnosis, despite the FNA being “diagnostic.” One patient received false positive diagnosis of malignancy by FNA. Of the 24 patients with incorrect diagnosis on FNA, 15 (62.5%) received the correct diagnosis of pleomorphic adenoma with intraoperative frozen section, though one patient received a false positive for malignancy and underwent surgical upstage unnecessarily. For pleomorphic adenoma, it appears that diagnostic sensitivity increases from 82% for FNA to 92% with frozen section. Conclusion: While FNA is commonly used as preoperative diagnostic adjunct for parotid masses, one must exercise caution, even in the context of a diagnostic sample, as nearly 18% of pleomorphic adenomas were not identified. Fortunately, misdiagnosis was benign 95% of time, and subsequently had no surgical implications
Lived experiences of tuberculosis patients undergoing short course chemotherapy
There were eleven (11) participants who took part in the study; the youngest is 21 years old whereas the oldest is 78 years old and they were chosen through purposive sampling technique. Phenomenology was used in this study to vividly describe the lived experiences of the participants. Being TB patients undergoing short-course chemotherapy was the phenomenon and the patients themselves were the ones who described their experiences. The analysis of data was based on Colaizzi\u27s phenomenological approach. The researchers used in-depth interviews for each participant of the study using a tape recorder. Observation of nonverbal cues was also done while the interviews were being conducted. After the researchers anayzed the data gathered, five (5) themes emerged. The first theme, Exposition, reveals the possible factors affecting the immune system of the participants that led to the development of the TB disease. The second theme, Rising Action, presents the different situations that arose before the participants were diagnosed as TB patients and before undergoing short-source chemotherapy as their treatment strategy. The third theme, Climax, focuses on the difficulties encountered by the participants. The fourth theme, Falling Action, reveals the changes and the progress happening to the participants as a result of the treatment. Lastly, the Denouement presents the coping of the participants during their treatment