Asthma causation and the gastrointestinal microbiome and metabolome: might there be a signal, or is it just noise?

No abstract available

Factors Affecting Ruminal Hydrogen Sulfide Concentration of Cattle

Ruminal hydrogen sulfide concentrations may be a useful tool to determine risk of cattle developing sulfurinduced polioencephalomalacia. In this study, steers were fed a low sulfur (0.2% S) or a high sulfur diet (0.7% S) and ruminal hydrogen sulfide concentrations were measured. Although differences in ruminal hydrogen sulfide due to sulfur intake were maintained throughout the day, concentrations within treatment varied greatly throughout the day. Ruminal hydrogen sulfide concentrations peaked during the period from 6 to 10 hours after feeding. More research is needed to develop a threshold of ruminal hydrogen sulfide that may cause polioencephalomalacia. Additionally, time of sampling after feeding will need to be standardized for this risk assessment method to be successful

A Review of the Thermodynamic, Transport, and Chemical Reaction Rate Properties of High-temperature Air

Thermodynamic and transport properties of high temperature air, and the reaction rates for the important chemical processes which occur in air, are reviewed. Semiempirical, analytic expressions are presented for thermodynamic and transport properties of air. Examples are given illustrating the use of these properties to evaluate (1) equilibrium conditions following shock waves, (2) stagnation region heat flux to a blunt high-speed body, and (3) some chemical relaxation lengths in stagnation region flow

Structure of the RNA-dependent RNA polymerase of poliovirus

AbstractBackground: The central player in the replication of RNA viruses is the viral RNA-dependent RNA polymerase. The 53 kDa poliovirus polymerase, together with other viral and possibly host proteins, carries out viral RNA replication in the host cell cytoplasm. RNA-dependent RNA polymerases comprise a distinct category of polymerases that have limited sequence similarity to reverse transcriptases (RNA-dependent DNA polymerases) and perhaps also to DNA-dependent polymerases. Previously reported structures of RNA-dependent DNA polymerases, DNA-dependent DNA polymerases and a DNA-dependent RNA polymerase show that structural and evolutionary relationships exist between the different polymerase categories.Results: We have determined the structure of the RNA-dependent RNA polymerase of poliovirus at 2.6 Å resolution by X-ray crystallography. It has the same overall shape as other polymerases, commonly described by analogy to a right hand. The structures of the ‘fingers’ and ‘thumb’ subdomains of poliovirus polymerase differ from those of other polymerases, but the palm subdomain contains a core structure very similar to that of other polymerases. This conserved core structure is composed of four of the amino acid sequence motifs described for RNA-dependent polymerases. Structure-based alignments of these motifs has enabled us to modify and extend previous sequence and structural alignments so as to relate sequence conservation to function. Extensive regions of polymerase–polymerase interactions observed in the crystals suggest an unusual higher order structure that we believe is important for polymerase function.Conclusions: As a first example of a structure of an RNA-dependent RNA polymerase, the poliovirus polymerase structure provides for a better understanding of polymerase structure, function and evolution. In addition, it has yielded insights into an unusual higher order structure that may be critical for poliovirus polymerase function

Modeled alongshore circulation and force balances onshore of a submarine canyon

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 120 (2015): 1887–1903, doi:10.1002/2014JC010555.Alongshore force balances, including the role of nonlinear advection, in the shoaling and surf zones onshore of a submarine canyon are investigated using a numerical modeling system (Delft3D/SWAN). The model is calibrated with waves and alongshore flows recorded over a period of 1.5 months at 26 sites along the 1.0, 2.5, and 5.0 m depth contours spanning about 2 km of coast. Field observation-based estimates of the alongshore pressure and radiation-stress gradients are reproduced well by the model. Model simulations suggest that the alongshore momentum balance is between the sum of the pressure and radiation-stress gradients and the sum of the nonlinear advective terms and bottom stress, with the remaining terms (e.g., wind stress and turbulent mixing) being negligible. The simulations also indicate that unexplained residuals in previous field-based estimates of the momentum balance may be owing to the neglect of the nonlinear advective terms, which are similar in magnitude to the sum of the forcing (pressure and radiations stress gradients) and to the bottom stress.Funding was provided by a joint WHOI-USGS postdoctoral scholarship, NSF, ONR, and ASD(R&E).2015-09-2

Analysis of EEC Regulation 2092/91 in relation to other national and international organic standards

This Deliverable 3.2 report presents an analysis of differences between EEC Regulation 2092/91 and other organic standards and their implementation, using a specially developed database (www.organicrules.org). It further reports on database development. The work was carried out as part of the “EEC 2092/91 (Organic) Revision” STREP project (No. SSPE-CT- 2004-502397) within the EU 6th Framework Programme. The main objective was to identify differences in organic standards in relation to Regulation (EEC) 2092/91 and to analyse selected national governmental and private organic standards with the aim of identifying specific areas in the (EEC) 2092/91 where revision in terms of harmonisation, regionalisation or simplification may be possible

Examining peer-controlled KR schedules during the learning of a movement-timing task as a function of task experience.

Learners can be provided with feedback in the form of knowledge of results (KR), under self-controlled and peer-controlled schedules. Recently, McRae, Hansen, and Patterson (2015), identified that inexperienced peers can provide KR that can facilitate motor skill acquisition. However, it is currently unknown whether previous task experience differentially impacts how peers present learners with KR and whether this KR impacts motor skill acquisition. In the present study, participants were randomly assigned to become inexperienced peer facilitators, learners with an inexperienced peer, learners with self-control who later became experienced peers, learners with an experienced peer, or learners in a control group. During acquisition learners completed a serial-timing task with a goal of 2500ms and returned approximately twenty four hours later for a delayed retention, time transfer, and pattern transfer test. We predicted that during the delayed tests, learners with self-control would outperform all other groups. Furthermore, we predicted that learners who received KR from experienced peers would outperform learners who received KR from inexperienced peers. However, our results indicated that participants who received peer-controlled and self-controlled KR schedules learned the task in an equivalent manner. Thus, our results are novel as they identify that inexperienced peers can provide KR that is as effective as KR provided by experienced peers and KR requested under self-controlled conditions