Wind erosion in semiarid landscapes: Predictive models and remote sensing methods for the influence of vegetation

Wind erosion in semi-arid regions is a significant problem for which the sheltering effect of rangeland vegetation is poorly understood. Individual plants may be considered as porous roughness elements which absorb or redistribute the wind's momentum. The saltation threshold is the minimum wind velocity at which soil movement begins. The dependence of the saltation threshold on geometrical parameters of a uniform roughness array was studied in a wind tunnel. Both solid and porous elements were used to determine relationships between canopy structure and the threshold velocity for soil transport. The development of a predictive relation for the influence of vegetation canopy structure on wind erosion of soil is discussed

Structural Steel Connection Design For Tensile Rupture by Advanced Inelastic Analysis

Connections are critical in structural steel buildings for transferring forces from member to member. Connections must be designed for safety and to ensure they serve their intended function. Many resources are available to engineers designing connections with common configurations and loads. But connection designers often encounter configurations and loading conditions for which there is little guidance. In these cases, design by advanced inelastic analysis can be advantageous. IDEA StatiCa is a steel connection design software for design by advanced inelastic analysis. In this software, some limit states are captured in the same manner as standard strength equations, while others are not. The net-section tensile rupture limit state is among the most basic limit states not captured using standard strength equations. It is not necessary to use standard strength equations in design by advanced inelastic analysis if the analysis provides a comparable or higher level of reliability. To date, no rigorous reliability analysis has been performed to show IDEA StatiCa, and the underlying component-based finite element method, provides a comparable or higher level of reliability than provided by the standard strength equations. Such a reliability analysis is performed in this work for the limit state of tensile rupture. Data from hundreds of previously published experimental results exhibiting tensile rupture in a variety of connection types were examined and analyzed. Strengths from both standard equations and IDEA StatiCa were compared to the experimentally obtained strengths and to each other. A reliability analysis based on Monte Carlo simulations was conducted using results from the strength comparisons. Additionally, the sensitivity of the IDEA StatiCa strength to mesh parameters and plastic strain limit was quantified. The results indicate that IDEA StatiCa does, in most cases, provide a comparable or higher level of reliability than the standard strength equations. Cases where it does not are identified and options for modifications are recommended. Documentation of the level of safety provided by IDEA StatiCa for the tensile rupture limit state presented in this work will bring confidence to the overall approach and enable the wider use of this helpful tool

Expressed in the yeast Saccharomyces cerevisiae, human ERK5 is a client of the Hsp90 chaperone that complements loss of the Slt2p (Mpk1p) cell integrity stress-activated protein kinase

ERK5 is a mitogen-activated protein (MAP) kinase regulated in human cells by diverse mitogens and stresses but also suspected of mediating the effects of a number of oncogenes. Its expression in the slt2Delta Saccharomyces cerevisiae mutant rescued several of the phenotypes caused by the lack of Slt2p (Mpk1p) cell integrity MAP kinase. ERK5 is able to provide this cell integrity MAP kinase function in yeast, as it is activated by the cell integrity signaling cascade that normally activates Slt2p and, in its active form, able to stimulate at least one key Slt2p target (Rlm1p, the major transcriptional regulator of cell wall genes). In vitro ERK5 kinase activity was abolished by Hsp90 inhibition. ERK5 activity in vivo was also lost in a strain that expresses a mutant Hsp90 chaperone. Therefore, human ERK5 expressed in yeast is an Hsp90 client, despite the widely held belief that the protein kinases of the MAP kinase class are non-Hsp90-dependent activities. Two-hybrid and protein binding studies revealed that strong association of Hsp90 with ERK5 requires the dual phosphorylation of the TEY motif in the MAP kinase activation loop. These phosphorylations, at positions adjacent to the Hsp90-binding surface recently identified for a number of protein kinases, may cause a localized rearrangement of this MAP kinase region that leads to creation of the Hsp90-binding surface. Complementation of the slt2Delta yeast defect by ERK5 expression establishes a new tool with which to screen for novel agonists and antagonists of ERK5 signaling as well as for isolating mutant forms of ERK5

Vectors for N- or C-terminal positioning of the yeast Gal4p DNA binding or activator domains

EMTREE drug terms: fungal protein; heat shock protein 90; hybrid protein; transcription factor EMTREE medical terms: amino terminal sequence; article; carboxy terminal sequence; DNA binding; DNA binding domain; expression vector; Gal4p domain; gene activation; gene activation domain; gene expression; nonhuman; plasmid; plasmid ADC; plasmid BDC; protein domain; protein protein interaction; technique; two hybrid system; yeast MeSH: Binding Sites; DNA-Binding Proteins; Genetic Vectors; Protein Structure, Tertiary; Recombinant Fusion Proteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Trans-Activation (Genetics); Transcription Factors; Two-Hybrid System Techniqu

Body Condition Score Change throughout Lactation Utilizing an Automated BCS System: A Descriptive Study

Body condition scoring (BCS) is a traditional visual technique often using a five-point scale to non-invasively assess fat reserves in cattle. However, recent studies have highlighted the potential in automating body condition scoring using imaging technology. Therefore, the objective was to implement a commercially available automated body condition scoring (ABCS) camera system to collect data for developing a predictive equation of body condition dynamics throughout the lactation period. Holstein cows (n = 2343, parity = 2.1 ± 1.1, calving BCS = 3.42 ± 0.24), up to 300 days in milk (DIM), were scored daily using two ABCS cameras mounted on sort-gates at the milk parlor exits. Scores were reported on a 1 to 5 scale in 0.1 increments. Lactation number, DIM, disease status, and 305d-predicted-milk-yield (305PMY) were used to create a multivariate prediction model for body condition scores throughout lactation. The equation derived from the model was: ABCSijk = 1.4838 − 0.00452 × DIMi − 0.03851 × Lactation numberj + 0.5970 × Calving ABCSk + 0.02998 × Disease Status(neg)l − 1.52 × 10−6 × 305PMYm + eijklm. We identified factors which are significant for predicting the BCS curve during lactation. These could be used to monitor deviations or benchmark ABCS in lactating dairy cows. The advantage of BCS automation is that it may provide objective, frequent, and accurate BCS with a higher degree of sensitivity compared with more sporadic and subjective manual BCS. Applying ABCS technology in future studies on commercial dairies may assist in providing improved dairy management protocols based on more available BCS

Neurotransmitter identity is acquired in a lineage-restricted manner in the Drosophila CNS

The vast majority of the adult fly ventral nerve cord is composed of 34 hemilineages, which are clusters of lineally related neurons. Neurons in these hemilineages use one of the three fast-acting neurotransmitters (acetylcholine, GABA, or glutamate) for communication. We generated a comprehensive neurotransmitter usage map for the entire ventral nerve cord. We did not find any cases of neurons using more than one neurotransmitter, but found that the acetylcholine specific gene ChAT is transcribed in many glutamatergic and GABAergic neurons, but these transcripts typically do not leave the nucleus and are not translated. Importantly, our work uncovered a simple rule: All neurons within a hemilineage use the same neurotransmitter. Thus, neurotransmitter identity is acquired at the stem cell level. Our detailed transmitter- usage/lineage identity map will be a great resource for studying the developmental basis of behavior and deciphering how neuronal circuits function to regulate behavior

A Conserved Cytoskeletal Signaling Cascade Mediates Neurotoxicity of FTDP-17 Tau Mutations In Vivo

The microtubule binding proteintau is strongly implicated in multiple neurodegenerative disorders, includingfrontotemporal dementia and parkinsonism linkedto chromosome 17 (FTDP-17), which is caused by mutations intau.In vitro, FTDP-17 mutant versions oftau can reduce microtubule binding and increase the aggregation of tau, but the mechanism by which these mutations promote disease in vivo is not clear. Here we take a combined biochemical and in vivo modeling approach to define functional properties of tau driving neurotoxicity in vivo. We express wild-type human tau and five FTDP-17 mutant forms of tau inDrosophila using a site-directed insertion strategy to ensure equivalent levels of expression. We then analyze multiple markers of neurodegeneration and neurotoxicity in transgenic animals, including analysis of both males and females. We find that FTDP-17 mutations act to enhance phosphorylation of tau and thus promote neurotoxicity in an in vivo setting. Further, we demonstrate that phosphorylation-dependent excess stabilization of the actin cytoskeleton is a key phosphorylation-dependent mediator of the toxicity of wild-type tau and of all the FTDP-17 mutants tested. Finally, we show that important downstream pathways, including autophagy and the unfolded protein response, are coregulated with neurotoxicity and actin cytoskeletal stabilization in brains of flies expressing wild-type human and various FTDP-17 tau mutants, supporting a conserved mechanism of neurotoxicity of wild-type tau and FTDP-17 mutant tau in disease pathogenesis.This work wassupported by National Institutes of Health-National Institute of Neurological Disorders and Stroke Grant R01-NS-08339