1,488 research outputs found
The dynamics of apparent horizons in Robinson-Trautman spacetimes
We present an alternative scheme of finding apparent horizons based on
spectral methods applied to Robinson-Trautman spacetimes. We have considered
distinct initial data such as representing the spheroids of matter and the
head-on collision of two non-rotating black holes. The evolution of the
apparent horizon is presented. We have obtained in some cases a mass gap
between the final Bondi and apparent horizon masses, whose implications were
briefly commented in the light of the thermodynamics of black holes.Comment: 9 pages, 7 figure
Extended treatment with interferon and ribavirin in a hemodialysis patient with chronic hepatitis C
Hemodialysis patient with chronic HCV infection,who was started on monotherapy with interferon.Qualitative HCV RNA remained positive at 12 weeks of treatment; ribavirin was associated. HCV RNA was negative at week 24 and treatment was extended to 72 weeks. HCV RNA negative six months after treatment.19319
The psychosocial cost burden of cancer : A systematic literature review
BACKGROUND AND OBJECTIVE: Psychosocial costs, or quality of life costs, account for psychological distress, pain, suffering and other negative experiences associated with cancer. They contribute to the overall economic burden of cancer that patients experience. But this category of costs remains poorly understood. This hinders opportunities to make the best cancer control policy decisions. This study explored the psychosocial cost burden associated with cancer, how studies measure psychosocial costs and the impact of this burden. METHODS: A systematic literature review of academic and grey literature published from 2008 to 2018 was conducted by searching electronic databases, guided by the Institute of Medicine's conceptualization of psychosocial burden. Results were analyzed using a narrative synthesis and a weighted proportion of populations affected was calculated. Study quality was assessed using the Ottawa-Newcastle instrument. RESULTS: A total of 25 studies were included. There was variation in how psychosocial costs were conceptualized and an inconsistent approach to measurement. Most studies measured social dimensions and focused on the financial consequences of paying for care. Fewer studies assessed costs associated with the other domains of this burden, including psychological, physical, and spiritual dimensions. Fourty-four percent of cancer populations studied were impacted by psychosocial costs and this varied by disease site (38%-71%). Two studies monetized the psychosocial cost burden, estimating a lifetime cost per case ranging from CAD528769. Studies were of varying quality; 60% of cross-sectional studies had a high risk of bias. CONCLUSIONS: Consistency in approach to measurement would help to elevate this issue for researchers and decision makers. At two-thirds of the total economic burden of cancer, economic evaluations should account for psychosocial costs to better inform decision-making. More support is needed to address the psychosocial cost burden faced by patients and their families
Clonal diversity and conservation genetics of the medicinal plant Carapichea ipecacuanha (Rubiaceae)
The roots of the understorey shrub Carapichea ipecacuanha (ipecac) have medicinal properties, and the uprooting of wild plants has supplied most of the world demand for this species. Although under severe population decline, C. ipecacuanha lacks legal protection. In the wild, the aerial stems of ipecac clump together to form clusters with well-defined borders. Cluster size may range from several to hundreds of aerial stems. To investigate the extent of clonality among aerial stems in ipecac clusters, we sampled 50 wild clusters (a total of 291 aerial stems) and screened them with 89 inter-simple sequence repeat (ISSR) markers. The 291 aerial stems were grouped into 42 putative clones. The clonal groups generally consisted of aerial stems from the same cluster, and there was little or no genetic differentiation among aerial stems at the cluster level. These findings suggest that strategies designed to conserve ipecac in situ should not rely upon census data, which are based on the number of aerial stems per cluster and the number of clusters per population, because such data greatly underestimate the species effective population size and genetic diversity. Our results also indicate that this species needs protection at a federal level
Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient
We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide
Proteomic Analysis of the Secretory Response of Aspergillus niger to D-Maltose and D-Xylose
Fungi utilize polysaccharide substrates through extracellular digestion catalyzed by secreted enzymes. Thus far, protein secretion by the filamentous fungus Aspergillus niger has mainly been studied at the level of individual proteins and by genome and transcriptome analyses. To extend these studies, a complementary proteomics approach was applied with the aim to investigate the changes in secretome and microsomal protein composition resulting from a shift to a high level secretion condition. During growth of A. niger on d-sorbitol, small amounts of d-maltose or d-xylose were used as inducers of the extracellular amylolytic and xylanolytic enzymes. Upon induction, protein compositions in the extracellular broth as well as in enriched secretory organelle (microsomal) fractions were analyzed using a shotgun proteomics approach. In total 102 secreted proteins and 1,126 microsomal proteins were identified in this study. Induction by d-maltose or d-xylose resulted in the increase in specific extracellular enzymes, such as glucoamylase A on d-maltose and β-xylosidase D on d-xylose, as well as of microsomal proteins. This reflects the differential expression of selected genes coding for dedicated extracellular enzymes. As expected, the addition of extra d-sorbitol had no effect on the expression of carbohydrate-active enzymes, compared to addition of d-xylose or d-maltose. Furthermore, d-maltose induction caused an increase in microsomal proteins related to translation (e.g., Rpl15) and vesicular transport (e.g., the endosomal-cargo receptor Erv14). Millimolar amounts of the inducers d-maltose and d-xylose are sufficient to cause a direct response in specific protein expression levels. Also, after induction by d-maltose or d-xylose, the induced enzymes were found in microsomes and extracellular. In agreement with our previous findings for d-xylose induction, d-maltose induction leads to recruitment of proteins involved in proteasome-mediated degradation
Phytogeographical patterns of dry forests sensu stricto in northern Minas Gerais State, Brazil
Extended treatment with interferon and ribavirin in a hemodialysis patient with chronic hepatitis C
Gastrointestinal complaints in runners are not due to small intestinal bacterial overgrowth
<p>Abstract</p> <p>Background</p> <p>Gastrointestinal complaints are common among long distance runners. We hypothesised that small intestinal bacterial overgrowth (SIBO) is present in long distance runners frequently afflicted with gastrointestinal complaints.</p> <p>Findings</p> <p>Seven long distance runners (5 female, mean age 29.1 years) with gastrointestinal complaints during and immediately after exercise without known gastrointestinal diseases performed Glucose hydrogen breath tests for detection of SIBO one week after a lactose hydrogen breath test checking for lactose intolerance. The most frequent symptoms were diarrhea (5/7, 71%) and flatulence (6/7, 86%). The study was conducted at a laboratory.</p> <p>In none of the subjects a pathological hydrogen production was observed after the intake of glucose. Only in one athlete a pathological hydrogen production was measured after the intake of lactose suggesting lactose intolerance.</p> <p>Conclusions</p> <p>Gastrointestinal disorders in the examined long distance runners were not associated with small intestinal bacterial overgrowth.</p
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