121 research outputs found
Longâterm Production and Profitability from Grazing Cattle in the Northern Mixed GrassPrairie
Conventional wisdom among rangeland professionals has been that for longâterm sustainability of grazing livestock operations, rangeland should be kept in high good to low excellent range condition. Our objective was to analyze production parameters, economic costs, returns, and profit using data generated over a thirtyâfour year period (1969â2002) from grazing a Clayey range site in the mixedâgrass prairie of western South Dakota with variable stocking rates required to maintain pastures in lowâfair, good, and excellent range condition classes. Cattle weights were measured at turnout and at the end of the grazing season. Gross income per acre was calculated by multiplying total gain per acre times price using historical National Agricultural Statistics Services feeder cattle prices. Annual variable costs were estimated from a historical yearling cattle budget developed by South Dakota State University (SDSU) agricultural economists. All economic values were adjusted to a constant dollar using the Bureau of Labor Statisticsâ Consumer Price Index. Stocking rate, average daily gain, total gain, net profit, gross revenue, and annual costs per acre varied among range condition classes. Net income for lowâfair range condition (11.86 per acre) were not different, but both were greater (P \u3c 0.01) than excellent range condition ($ 9.31 per acre). Over the life of the study, real profit (adjusted for inflation) steadily increased (P \u3c 0.01) for the lowâfair and good treatments while it remained level for the excellent treatment. Neither drought nor wet springs impacted profit differently for the three treatments. These results support generally observed rancher behavior regarding range condition: to maintain their rangeland in a lower range condition than would be normally recommend by rangeland professionals. Ecosystem goods and services of increasing interest to society and associated with high range condition, such as floristic diversity, hydrologic function, and wildlife cover, come at an opportunity cost to the rancher
Clusters of galaxies: setting the stage
Clusters of galaxies are self-gravitating systems of mass ~10^14-10^15 Msun.
They consist of dark matter (~80 %), hot diffuse intracluster plasma (< 20 %)
and a small fraction of stars, dust, and cold gas, mostly locked in galaxies.
In most clusters, scaling relations between their properties testify that the
cluster components are in approximate dynamical equilibrium within the cluster
gravitational potential well. However, spatially inhomogeneous thermal and
non-thermal emission of the intracluster medium (ICM), observed in some
clusters in the X-ray and radio bands, and the kinematic and morphological
segregation of galaxies are a signature of non-gravitational processes, ongoing
cluster merging and interactions. In the current bottom-up scenario for the
formation of cosmic structure, clusters are the most massive nodes of the
filamentary large-scale structure of the cosmic web and form by anisotropic and
episodic accretion of mass. In this model of the universe dominated by cold
dark matter, at the present time most baryons are expected to be in a diffuse
component rather than in stars and galaxies; moreover, ~50 % of this diffuse
component has temperature ~0.01-1 keV and permeates the filamentary
distribution of the dark matter. The temperature of this Warm-Hot Intergalactic
Medium (WHIM) increases with the local density and its search in the outer
regions of clusters and lower density regions has been the quest of much recent
observational effort. Over the last thirty years, an impressive coherent
picture of the formation and evolution of cosmic structures has emerged from
the intense interplay between observations, theory and numerical experiments.
Future efforts will continue to test whether this picture keeps being valid,
needs corrections or suffers dramatic failures in its predictive power.Comment: 20 pages, 8 figures, accepted for publication in Space Science
Reviews, special issue "Clusters of galaxies: beyond the thermal view",
Editor J.S. Kaastra, Chapter 2; work done by an international team at the
International Space Science Institute (ISSI), Bern, organised by J.S.
Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke
The Global Invertebrate Genomics Alliance (GIGA): developing community resources to study diverse invertebrate genomes
Over 95% of all metazoan (animal) species comprise the invertebrates, but very few genomes from these organisms have been sequenced. We have, therefore, formed a Global Invertebrate Genomics Alliance (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site (http://giga.nova.edu) has been launched to facilitate this collaborative venture
The genomics of heart failure: design and rationale of the HERMES consortium
Aims The HERMES (HEart failure Molecular Epidemiology for Therapeutic targets) consortium aims to identify the genomic and molecular basis of heart failure.Methods and results The consortium currently includes 51 studies from 11 countries, including 68 157 heart failure cases and 949 888 controls, with data on heart failure events and prognosis. All studies collected biological samples and performed genome-wide genotyping of common genetic variants. The enrolment of subjects into participating studies ranged from 1948 to the present day, and the median follow-up following heart failure diagnosis ranged from 2 to 116 months. Forty-nine of 51 individual studies enrolled participants of both sexes; in these studies, participants with heart failure were predominantly male (34-90%). The mean age at diagnosis or ascertainment across all studies ranged from 54 to 84 years. Based on the aggregate sample, we estimated 80% power to genetic variant associations with risk of heart failure with an odds ratio of >1.10 for common variants (allele frequency > 0.05) and >1.20 for low-frequency variants (allele frequency 0.01-0.05) at P Conclusions HERMES is a global collaboration aiming to (i) identify the genetic determinants of heart failure; (ii) generate insights into the causal pathways leading to heart failure and enable genetic approaches to target prioritization; and (iii) develop genomic tools for disease stratification and risk prediction.</p
The dual nature of perfectionism in sports: Relationships with emotion, motivation, and performance
Perfectionism is a prevalent characteristic in athletes. Yet some researchers have argued that perfectionism in sports is maladaptive because it undermines athletesâ performance and stifles athletic development. This argument, however, neglects that perfectionism is a multidimensional characteristic and that only some dimensions of perfectionism are clearly maladaptive, whereas others are not. This review argues that perfectionism is comprised of two main dimensions?perfectionistic strivings and perfectionistic concerns (Stoeber & Otto, 2006)?that show different and unique pattern of relationships with athletesâ emotion, motivation, and performance. In support of this argument the review will present findings indicating that only perfectionistic concerns show unique positive relationships with competitive anxiety, fear of failure, and avoidance goal orientations. In contrast, perfectionistic strivings show unique positive relationships with self-confidence, hope of success, approach goal orientations, and performance in training and competitions. The findings suggest that only perfectionistic concerns are clearly maladaptive, whereas perfectionistic strivings may form part of a healthy striving for excellence. Implications for applied sport psychology are discussed as are open questions for future research
Sources of nonprotein-nitrogen as a substitute for protein in ruminant rations
Americans consume large quantities of meat. An increasing population will demand more production to maintain present consumption rates. Protein is an essential nutrient for all animals. The simple-stomached animals (pigs, chickens, dogs, human beings, etc.) can utilize only natural protein, whereas ruminant animals can use nonprotein-nitrogen as a source of ammonia to produce microbial protein in the rumen. This project was to evaluate various ammoniated phosphates in ruminant rations
Fine-grained auditory discrimination and performance on tests of receptive vocabulary and receptive language
Viral dieback of carrot and other umbelliferae caused by the Anthriscus strain of parsnip yellow fleck virus, and its distinction from carrot motley dwarf
- âŠ