486 research outputs found
Th e role of prescribed burning in maintenance of an endangered plant species, Lomatium bradshawii.
Abstract. Responses of a federally listed endangered plant species, Lomatium bradshawii, to the use of fire as a management tool for maintaining remnant wetland prairies were evaluated at two public land areas in the Willamette Valley of western Oregon. Areas containing L. bradshawii were treated with two or three fall season prescribed burns during a nine-year period. Foliar crown area, height, umbellets, and schizocarps of 150 L. bradshawii at Rose Prairie and 250 at Fisher Butte and the recruitment and density of L. bradshawii in 2-m 2 plots at both sites were documented during 1988-1996. When both sites were considered together, crown area, height, umbellets, and schizocarps per plant initially responded positively to burn treatments, but increases were not consistent across years or sites. Crown area tended to increase and then decline after each burn. Burning initially enhanced schizocarp production at both sites; schizocarps declined one or two years after burning but remained much higher in the burn treatments than in controls until 1996. Seedling production was not correlated with schizocarp production at either site. Umbellet and schizocarp production were not correlated with January-June temperatures or precipitation at the nearest weather station. Burning accentuated differences in size and reproductive capacity of L. bradshawii at the two sites and differentially affected recruitment and density. Random resampling of L. bradshawii in 1997 indicated that effects of repeated burning during the previous eight years were hard to detect. At Rose Prairie, foliar crown area, height, number of leaves, umbellets, and schizocarps in 1997 were similar or lower with burning than in unburned controls. At Fisher Butte, L. bradshawii in the two burn treatment were similar to control plants, but three burns significantly increased foliar crown area, number of leaves, and schizocarps. Monitoring recovery for one or two years after a burn may only capture the initial stimulation provided by burning and may foster unrealistically high expectations concerning the viability of an endangered plant population
Genomic analyses with biofilter 2.0: knowledge driven filtering, annotation, and model development
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ASPEN computer simulations of the mixed waste treatment project baseline flowsheet
The treatment and disposal of mixed waste (i.e., waste containing both hazardous and radioactive components) is a challenging waste- management problem of particular concern to Department of Energy (DOE) sites throughout the United States. Traditional technologies used for destroying hazardous wastes must be re- evaluated for their ability to handle mixed wastes, and, in some cases, new technologies must be developed. The Mixed Waste Treatment Project (MWTP), a collaborative effort between Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory, and Pacific Northwest Laboratory (PNL), was established by the DOE`s Waste Operations Program (EM-30) to develop and analyze alternative mixed waste treatment approaches. One of the MWTP`s initiatives, and the objective of this study, was to develop flowsheets for prototype, integrated, mixed-waste treatment facilities that can serve as models for sites developing their own treatment strategies. Evaluation of these flowsheets is being facilitated through the use of computer modeling. The objectives of the flowsheet simulations are to compare process effectiveness and costs of alternative flowsheets and to determine if commercial process-simulation software could be used on the large, complex process of an integrated mixed waste processing facility. Flowsheet modeling is needed to evaluate many aspects of proposed flowsheet designs. A major advantage of modeling the complete flowsheet is the ability to define the internal recycle streams, thereby making it possible to evaluate the impact of one operation on the whole plant. Many effects that can be seen only in this way. Modeling also can be used to evaluate sensitivity and range of operating conditions, radioactive criticality, and relative costs of different flowsheet designs. Further, the modeled flowsheets must be easily modified so that one can examine how alternative technologies and varying feed streams affect the overall integrated process
Cyborg Activism: Exploring the reconfigurations of democratic subjectivity in Anonymous
This article develops the concept of cyborg activism as novel configuration of democratic subjectivity in the Information Age by exploring the online collectivity Anonymous as a prototype. By fusing elements of human/machine and organic/digital the cyborg disrupts modern logics of binary thinking. Cyborg activism emerges as the reconfiguration of equality/hierarchy, reason/emotion, and nihilism/idealism. Anonymous demonstrates how through the use of contingent and ephemeral digital personae hierarchies in cyborg activism prove more volatile than in face-to-face settings. Emotions appear as an essential part of a politics of passion, which enables pursuing laughter and joy, expressing anger, and experiencing empowerment as part of a reasoned, strategic politics. Anonymous’ political content reconfigures nihilist sentiments, frustration, and political disenchantment on the one hand with idealist world views on the other. This enables the cohabitation and partial integration of a great diversity of political claims rooted in various ideologies
Communication in Diagnostic Radiology
Communication in the diagnostic radiology department in regard to the current work load has been discussed with certain recommendations being made to increase efficiency. The need for improvement in communication equipment and techniques is necessitated by problems facing diagnostic radiology today.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73519/1/j.1440-1673.1972.tb01316.x.pd
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PDRMIP: a precipitation driver and response model intercomparison project - protocol and preliminary results
PDRMIP investigates the role of various drivers of climate change for mean and extreme precipitation changes, based on multiple climate model output and energy budget analyses.
As the global temperature increases with changing climate, precipitation rates and patterns are affected through a wide range of physical mechanisms. The globally averaged intensity of extreme precipitation also changes more rapidly than the globally averaged precipitation rate. While some aspects of the regional variation in precipitation predicted by climate models appear robust, there is still a large degree of inter-model differences unaccounted for. Individual drivers of climate change initially alter the energy budget of the atmosphere leading to distinct rapid adjustments involving changes in precipitation. Differences in how these rapid adjustment processes manifest themselves within models are likely to explain a large fraction of the present model spread and needs better quantifications to improve precipitation predictions. Here, we introduce the Precipitation Driver and Response Model Intercomparison Project (PDRMIP), where a set of idealized experiments designed to understand the role of different climate forcing mechanisms were performed by a large set of climate models. PDRMIP focuses on understanding how precipitation changes relating to rapid adjustments and slower responses to climate forcings are represented across models. Initial results show that rapid adjustments account for large regional differences in hydrological sensitivity across multiple drivers. The PDRMIP results are expected to dramatically improve our understanding of the causes of the present diversity in future climate projections
Phenome-Wide Association Study (PheWAS) for Detection of Pleiotropy within the Population Architecture using Genomics and Epidemiology (PAGE) Network
Using a phenome-wide association study (PheWAS) approach, we comprehensively tested genetic variants for association with phenotypes available for 70,061 study participants in the Population Architecture using Genomics and Epidemiology (PAGE) network. Our aim was to better characterize the genetic architecture of complex traits and identify novel pleiotropic relationships. This PheWAS drew on five population-based studies representing four major racial/ethnic groups (European Americans (EA), African Americans (AA), Hispanics/Mexican-Americans, and Asian/Pacific Islanders) in PAGE, each site with measurements for multiple traits, associated laboratory measures, and intermediate biomarkers. A total of 83 single nucleotide polymorphisms (SNPs) identified by genome-wide association studies (GWAS) were genotyped across two or more PAGE study sites. Comprehensive tests of association, stratified by race/ethnicity, were performed, encompassing 4,706 phenotypes mapped to 105 phenotype-classes, and association results were compared across study sites. A total of 111 PheWAS results had significant associations for two or more PAGE study sites with consistent direction of effect with a significance threshold of p<0.01 for the same racial/ethnic group, SNP, and phenotype-class. Among results identified for SNPs previously associated with phenotypes such as lipid traits, type 2 diabetes, and body mass index, 52 replicated previously published genotype-phenotype associations, 26 represented phenotypes closely related to previously known genotype-phenotype associations, and 33 represented potentially novel genotype-phenotype associations with pleiotropic effects. The majority of the potentially novel results were for single PheWAS phenotype-classes, for example, for CDKN2A/B rs1333049 (previously associated with type 2 diabetes in EA) a PheWAS association was identified for hemoglobin levels in AA. Of note, however, GALNT2 rs2144300 (previously associated with high-density lipoprotein cholesterol levels in EA) had multiple potentially novel PheWAS associations, with hypertension related phenotypes in AA and with serum calcium levels and coronary artery disease phenotypes in EA. PheWAS identifies associations for hypothesis generation and exploration of the genetic architecture of complex traits
Proteomics Analysis of Human Skeletal Muscle Reveals Novel Abnormalities in Obesity and Type 2 Diabetes
Variation in LPA Is Associated with Lp(a) Levels in Three Populations from the Third National Health and Nutrition Examination Survey
The distribution of lipoprotein(a) [Lp(a)] levels can differ dramatically across diverse racial/ethnic populations. The extent to which genetic variation in LPA can explain these differences is not fully understood. To explore this, 19 LPA tagSNPs were genotyped in 7,159 participants from the Third National Health and Nutrition Examination Survey (NHANES III). NHANES III is a diverse population-based survey with DNA samples linked to hundreds of quantitative traits, including serum Lp(a). Tests of association between LPA variants and transformed Lp(a) levels were performed across the three different NHANES subpopulations (non-Hispanic whites, non-Hispanic blacks, and Mexican Americans). At a significance threshold of p<0.0001, 15 of the 19 SNPs tested were strongly associated with Lp(a) levels in at least one subpopulation, six in at least two subpopulations, and none in all three subpopulations. In non-Hispanic whites, three variants were associated with Lp(a) levels, including previously known rs6919246 (p = 1.18×10−30). Additionally, 12 and 6 variants had significant associations in non-Hispanic blacks and Mexican Americans, respectively. The additive effects of these associated alleles explained up to 11% of the variance observed for Lp(a) levels in the different racial/ethnic populations. The findings reported here replicate previous candidate gene and genome-wide association studies for Lp(a) levels in European-descent populations and extend these findings to other populations. While we demonstrate that LPA is an important contributor to Lp(a) levels regardless of race/ethnicity, the lack of generalization of associations across all subpopulations suggests that specific LPA variants may be contributing to the observed Lp(a) between-population variance
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