Nitrate Concentrations of Annual Forages Grown for Grazing in Nebraska

Annual forage samples sent by producers to Ward Laboratories Inc. for nitrate analysis were evaluated to determine which cover crop species in Nebraska are most likely to accumulate nitrates, and how often the accumulated nitrates are considered toxic by traditional recommendations. Additionally, nitrate levels of cover crop mixes grown in research trials were analyzed to ensure species differences were repeated when grown together in the same fields. Brassicas accumulate more nitrate than small grains, millet, sorghum/sudan grasses, or cover crop mixes. Brassicas accumulated levels of nitrate considered moderately to highly toxic in 48% of the samples. The other cover crop species accumulated potentially toxic nitrate levels in 20–28% of the samples. However, when cattle graze these forages, there are multiple factors that may mitigate toxicity. Cattle have grazed annual forages containing nitrate concentrations considered toxic, and no adverse health consequences were observed. More research is needed to reevaluate the risk of nitrate toxicity when grazing cover crops

Nitrate Concentrations of Annual Forages Grown for Grazing in Nebraska

Annual forage samples sent by producers to Ward Laboratories Inc. for nitrate analysis were evaluated to determine which cover crop species in Nebraska are most likely to accumulate nitrates, and how often the accumulated nitrates are considered toxic by traditional recommendations. Additionally, nitrate levels of cover crop mixes grown in research trials were analyzed to ensure species differences were repeated when grown together in the same fields. Brassicas accumulate more nitrate than small grains, millet, sorghum/sudan grasses, or cover crop mixes. Brassicas accumulated levels of nitrate considered moderately to highly toxic in 48% of the samples. The other cover crop species accumulated potentially toxic nitrate levels in 20–28% of the samples. However, when cattle graze these forages, there are multiple factors that may mitigate toxicity. Cattle have grazed annual forages containing nitrate concentrations considered toxic, and no adverse health consequences were observed. More research is needed to reevaluate the risk of nitrate toxicity when grazing cover crops

Genome-wide diversity and gene expression profiling of Babesia microti isolates identify polymorphic genes that mediate host-pathogen interactions

Babesia microti, a tick-transmitted, intraerythrocytic protozoan parasite circulating mainly among small mammals, is the primary cause of human babesiosis. While most cases are transmitted by Ixodes ticks, the disease may also be transmitted through blood transfusion and perinatally. A comprehensive analysis of genome composition, genetic diversity, and gene expression profiling of seven B. microti isolates revealed that genetic variation in isolates from the Northeast United States is almost exclusively associated with genes encoding the surface proteome and secretome of the parasite. Furthermore, we found that polymorphism is restricted to a small number of genes, which are highly expressed during infection. In order to identify pathogen-encoded factors involved in host-parasite interactions, we screened a proteome array comprised of 174 B. microti proteins, including several predicted members of the parasite secretome. Using this immuno-proteomic approach we identified several novel antigens that trigger strong host immune responses during the onset of infection. The genomic and immunological data presented herein provide the first insights into the determinants of B. microti interaction with its mammalian hosts and their relevance for understanding the selective pressures acting on parasite evolution

Magnetic structure of Yb2Pt2Pb: Ising moments on the Shastry-Sutherland lattice.

Neutron diffraction measurements were carried out on single crystals and powders of Yb2Pt2Pb, where Yb moments form two interpenetrating planar sublattices of orthogonal dimers, a geometry known as Shastry-Sutherland lattice, and are stacked along the c axis in a ladder geometry. Yb2Pt2Pb orders antiferromagnetically at TN=2.07K, and the magnetic structure determined from these measurements features the interleaving of two orthogonal sublattices into a 5×5×1 magnetic supercell that is based on stripes with moments perpendicular to the dimer bonds, which are along (110) and (−110). Magnetic fields applied along (110) or (−110) suppress the antiferromagnetic peaks from an individual sublattice, but leave the orthogonal sublattice unaffected, evidence for the Ising character of the Yb moments in Yb2Pt2Pb that is supported by point charge calculations. Specific heat, magnetic susceptibility, and electrical resistivity measurements concur with neutron elastic scattering results that the longitudinal critical fluctuations are gapped with ΔE≃0.07meV

How Do Learners Interact with E-learning? Examining Patterns of Learner Control Behaviors

There has been significant debate in the literature on technology-mediated training about the appropriate role of learner control. We define learner control as giving trainees the ability to make choices about how they proceed through the learning environment. We explore two perspectives. First, we consider learners’ stated preferences for the extent of control in the learning environment. Second, we analyze the actual online learning behaviors of 518 trainees in a Fortune 500 organization. We compare a measure of learner control preferences to the most commonly used framework of learner control that comprises five dimensions: pace of instruction, sequence of topics, specific content covered, amount of advice/feedback provided, and type of media. We also compare the dimensionality of learner behaviors to this framework and examine the relationship between learner preferences and learner behaviors. Results suggest that fewer dimensions can capture both learner preferences and behaviors than what the literature currently suggests. Specifically, media control aligned with both pace and content control. The relationship between stated learner control preferences and learner control behaviors was relatively weak. However, we found support for the recently identified dimension of scheduling control and suggest a new learner control dimension of performance control, consistent with the importance of practice retrieval for learning

BRG1 mutations found in human cancer cell lines inactivate Rb-mediated cell-cycle arrest

Eukaryotic organisms package DNA into chromatin for compact storage in the cell nucleus. However, this process promotes transcriptional repression of genes. To overcome the transcriptional repression, chromatin remodeling complexes have evolved that alter the configuration of chromatin packaging of DNA into nucleosomes by histones. The SWI/SNF chromatin remodeling complex uses energy from ATP hydrolysis to reposition nucleosomes and make DNA accessible to transcription factors. Recent studies showing mutations of BRG1, one of 2 mutually exclusive ATPase subunits, in human tumor cell lines and primary tissue samples have implicated a role for its loss in cancer development. While most of the mutations lead to complete loss of BRG1 protein expression, others result in single amino acid substitutions. To better understand the role of these BRG1 point mutations in cancer development, we characterized SWI/SNF function in human tumor cell lines with these mutations in the absence of BRM expression, the other ATPase component. We found that the mutant BRG1 proteins still interacted with the core complex members and appeared at the promoters of target genes. However, while these mutations did not affect CD44 and CDH1 expression, known targets of the SWI/SNF complex, they did abrogate Rb mediated cell cycle arrest. Therefore, our results implicate that these mutations disrupt the de novo chromatin remodeling activity of the complex without affecting the status of existing nucleosome positioning

Automated eukaryotic gene structure annotation using EVidenceModeler and the Program to Assemble Spliced Alignments

EVidenceModeler (EVM) is an automated annotation tool that predicts protein-coding regions, alternatively spliced transcripts and untranslated regions of eukaryotic genes

A framework for human microbiome research

A variety of microbial communities and their genes (the microbiome) exist throughout the human body, with fundamental roles in human health and disease. The National Institutes of Health (NIH)-funded Human Microbiome Project Consortium has established a population-scale framework to develop metagenomic protocols, resulting in a broad range of quality-controlled resources and data including standardized methods for creating, processing and interpreting distinct types of high-throughput metagenomic data available to the scientific community. Here we present resources from a population of 242 healthy adults sampled at 15 or 18 body sites up to three times, which have generated 5,177 microbial taxonomic profiles from 16S ribosomal RNA genes and over 3.5 terabases of metagenomic sequence so far. In parallel, approximately 800 reference strains isolated from the human body have been sequenced. Collectively, these data represent the largest resource describing the abundance and variety of the human microbiome, while providing a framework for current and future studies

Cognitive Social Psychology

Social psychology is presently dominated by cognitive theories that emphasize the importance of personal beliefs and in tellective processes as the immediate determinants of behavior. The present paper explores two areas of.research within this tra dition : (1) beliefs about the external world, and (2) beliefs about the self. The paper concludes with a brief critique of the cognitive approach to social psychology.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69030/2/10.1177_014616727700300402.pd