Comparison of Two Low-Input Cow/Calf Production Systems on Temperate Grassland

Two systems of grass farming were compared in an eight-year experiment in West Virginia, USA. The grassland consisted primarily of cocksfoot (Dactylis glomerara L.), Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and red (Trifolium pretense L.) and white clover (T. repens L.). The objective was to compare two systems of beef cow calf production. The experiment was a randomized complete block with two replicated treatments. The grassland of treatment 1 (system 1) was overseeded with legumes, grazing started 1 wk earlier and continued 1 wk later than treatment 2 (system 2) and calves were allowed to forward creep graze. The hay land of treatment 2 received 56 kg N ha-1, at the start of the growing season. Response was measured as calf weaning weight, hay production, and pre-grazing herbage accumulation. Each treatment/replicate (experimental unit) was assigned 6.5 ha divided into three grassland managements units: pasture, buffer and meadow. Pasture was grazed and not cut for hay. First growth of buffer and meadow was harvested as hay. Subsequently, buffer was grazed, meadow was again harvested, followed by late season grazing. Management units were divided into four paddocks. Animals occupied a paddock for 7 days resulting in 4-week grazing cycles from May to mid-November. Eight cow/calf pairs grazed each treatment/replicate (stocking rate 1.23 cow calves ha-1 ). Calves, born in March, were weaned in late September. System 1 calves gained 1.18 kg dy-1 (P \u3c 0.04 SE=0.01) compared with those on System 2 which gained 1.14 kg dy-1. Annual hay production on System 2 was 5784 kg ha-1, significantly more than on System 1 (P \u3c 0.01 SE=107). However, in System 1 extending the grazing season reduced the amount of hay required annually by 1680 kg ha-1. System 1 hay had a greater proportion of legume (9 vs. 3%, P \u3c 0.01 SE=0.5) and a lesser proportion of grass (75 vs. 85%, P \u3c 0.01 SE=0.7) than those of system 2

The High Resolution X-ray Spectrum of SS 433 using the Chandra HETGS

We present observations of SS 433 using the Chandra High Energy Transmission Grating Spectrometer. Many emission lines of highly ionized elements are detected with the relativistic blue and red Doppler shifts. The lines are measurably broadened to 1700 km/s (FWHM) and the widths do not depend significantly on the characteristic emission temperature, suggesting that the emission occurs in a freely expanding region of constant collimation with opening angle of 1.23 +/- 0.06 deg. The blue shifts of lines from low temperature gas are the same as those of high temperature gas within our uncertainties, again indicating that the hottest gas we observe to emit emission lines is already at terminal velocity. Fits to the emission line fluxes give a range of temperatures in the jet from 5e6 to 1e8 K. We derive the emission measure as a function of temperature for a four component model that fits the line flux data. Using the density sensitive Si XIII triplet, the characteristic electron density is 1e14 cm^{-3}, where the gas temperature is about 1.3e7 K. Based on an adiabatic expansion model of the jet, the electron densities drop from ~2e15 to 4e13 cm^{-3} at distances of 2e10 to 2e11 cm from the apex of the jet cone. The jet mass outflow rate is 1.5e-7 Msun / yr. The kinetic power is 3.2e38 erg/s, which is x1000 larger than the unabsorbed 2-10 keV X-ray luminosity. The bremsstrahlung emission associated with the lines can account for the entire continuum; we see no direct evidence for an accretion disk. The image from zeroth order shows extended emission at a scale of ~2", aligned in the general direction of the radio jets.Comment: 28 pages, 12 figures (1, 4, 5, and 6 are color), to appear in the Astrophysical Journa

Insights into the O-Acetylation Reaction of Hydroxylated Heterocyclic Amines by Human Arylamine N-Acetyltransferases: A Computational Study

A computational study was performed to better understand the differences between human arylamine N-acetyltransferase (NAT) 1 and 2. Homology models were constructed from available crystal structures and comparisons of the active site residues 125, 127, and 129 for these two enzymes provide insight into observed substrate differences. The NAT2 model provided a basis for understanding how some of the common mutations may affect the structure of the protein. Molecular dynamics simulations of the human NAT models and the template structure (NAT from Mycobacterium smegmatis) were performed and showed the models to be stable and reasonable. Docking studies of hydroxylated heterocyclic amines in the models of NAT1 and NAT2 probed the differences exhibited by these two proteins with mutagenic agents. The hydroxylated heterocyclic amines were only able to fit into the NAT2 active site, and an alternative binding site by the P-loop was found using our models and will be discussed. Additionally, quantum mechanical calculations were performed to study the O-acetylation reaction of the hydroxylated heterocyclic amines N-OH MeIQx and N-OH PhIP. This study has given us insight into why there are substrate differences among isoenzymes and explains some of the polymorphic activity differences

Abiotic O_2 Levels on Planets around F, G, K, and M Stars: Effects of Lightning-produced Catalysts in Eliminating Oxygen False Positives

Over the last few years, a number of authors have suggested that, under certain circumstances, molecular oxygen (O_2) or ozone (O_3) generated by abiotic processes may accumulate to detectable concentrations in a habitable terrestrial planet's atmosphere, producing so-called "false positives" for life. But the models have occasionally disagreed with each other, with some predicting false positives, and some not, for the same apparent set of circumstances. We show here that photochemical false positives derive either from inconsistencies in the treatment of atmospheric and global redox balance or from the treatment (or lack thereof) of lightning. For habitable terrestrial planets with even trace amounts of atmospheric N_2, NO produced by lightning catalyzes the recombination of CO and O derived from CO_2 photolysis and should be sufficient to eliminate all reported false positives. Molecular oxygen thus remains a useful biosignature gas for Earth-like extrasolar planets, provided that the planet resides within the conventional liquid water habitable zone and has not experienced distinctly non-Earth-like, irrecoverable water loss

Teacher–Student relationship quality as a barometer of teaching and learning effectiveness: Conceptualization and measurement

Background. The teacher-student relationship (TSR) is instrumental for young children and adolescents’ socio-emotional development and wellbeing as well as academic engagement and progress. Aims. The primary aim of this study was to test the psychometric properties, including reliability and factorial, convergent, and predictive validity, of the Teacher-Student Relationship Quality Questionnaire (TSRQ-Q) with two samples of students. Sample(s). Participants were 294 students from secondary schools in the East Midlands and the East of England. Participants were separated into two samples; those who completed the TSRQ-Q with their physical education teacher in mind (n = 150 students) and those who completed it with their mathematics teacher in mind (n = 144 students). Method. A multi-section questionnaire comprised of the TSRQ-Q and other validated measures was completed on one occasion by students in both samples to assess their perceptions of the quality of the TSR, positive and negative affect, intrinsic motivation, physical self-concept, enjoyment, and perceived competence. Results. In both samples, the TSRQ-Q demonstrated good internal consistency, factorial, convergent, and predictive validity. The quality of the TSR had both direct and indirect effects through positive affect on student outcomes in mathematics and physical education. Conclusions. The TSRQ-Q is a valid measure for assessing students’ perceptions of the quality of the relationship with their teacher. The conceptual and practical significance of this unique relationship was reflected by its dual pathway effect on a range of student outcomes and via influencing students’ positive affect in the classroom

Multi-step self-guided pathways for shape-changing metamaterials

Multi-step pathways, constituted of a sequence of reconfigurations, are central to a wide variety of natural and man-made systems. Such pathways autonomously execute in self-guided processes such as protein folding and self-assembly, but require external control in macroscopic mechanical systems, provided by, e.g., actuators in robotics or manual folding in origami. Here we introduce shape-changing mechanical metamaterials, that exhibit self-guided multi-step pathways in response to global uniform compression. Their design combines strongly nonlinear mechanical elements with a multimodal architecture that allows for a sequence of topological reconfigurations, i.e., modifications of the topology caused by the formation of internal self-contacts. We realized such metamaterials by digital manufacturing, and show that the pathway and final configuration can be controlled by rational design of the nonlinear mechanical elements. We furthermore demonstrate that self-contacts suppress pathway errors. Finally, we demonstrate how hierarchical architectures allow to extend the number of distinct reconfiguration steps. Our work establishes general principles for designing mechanical pathways, opening new avenues for self-folding media, pluripotent materials, and pliable devices in, e.g., stretchable electronics and soft robotics.Comment: 16 pages, 3 main figures, 10 extended data figures. See https://youtu.be/8m1QfkMFL0I for an explanatory vide

What Does It Take? California County Funding Requests for Recovery-Oriented Full Service Partnerships Under the Mental Health Services Act

The need to move mental health systems toward more recovery-oriented treatment modes is well established. Progress has been made to define needed changes but evidence is lacking about the resources required to implement them. The Mental Health Services Act (MHSA) in California was designed to implement more recovery-oriented treatment modes. We use data from county funding requests and annual updates to examine how counties budgeted for recovery-oriented programs targeted to different age groups under MHSA. Findings indicate that initial per-client budgeting for Full Services Partnerships under MHSA was maintained in future cycles and counties budgeted less per client for children. With this analysis, we begin to benchmark resource allocation for programs that are intended to be recovery-oriented, which should be evaluated against appropriate outcome measures in the future to determine the degree of recovery-orientation

Minority and mode conversion heating in (3He)-H JET plasma

Radio frequency (RF) heating experiments have recently been conducted in JET (He-3)-H plasmas. This type of plasmas will be used in ITER's non-activated operation phase. Whereas a companion paper in this same PPCF issue will discuss the RF heating scenario's at half the nominal magnetic field, this paper documents the heating performance in (He-3)-H plasmas at full field, with fundamental cyclotron heating of He-3 as the only possible ion heating scheme in view of the foreseen ITER antenna frequency bandwidth. Dominant electron heating with global heating efficiencies between 30% and 70% depending on the He-3 concentration were observed and mode conversion (MC) heating proved to be as efficient as He-3 minority heating. The unwanted presence of both He-4 and D in the discharges gave rise to 2 MC layers rather than a single one. This together with the fact that the location of the high-field side fast wave (FW) cutoff is a sensitive function of the parallel wave number and that one of the locations of the wave confluences critically depends on the He-3 concentration made the interpretation of the results, although more complex, very interesting: three regimes could be distinguished as a function of X[He-3]: (i) a regime at low concentration (X[He-3] < 1.8%) at which ion cyclotron resonance frequency (ICRF) heating is efficient, (ii) a regime at intermediate concentrations (1.8 < X[He-3] < 5%) in which the RF performance is degrading and ultimately becoming very poor, and finally (iii) a good heating regime at He-3 concentrations beyond 6%. In this latter regime, the heating efficiency did not critically depend on the actual concentration while at lower concentrations (X[He-3] < 4%) a bigger excursion in heating efficiency is observed and the estimates differ somewhat from shot to shot, also depending on whether local or global signals are chosen for the analysis. The different dynamics at the various concentrations can be traced back to the presence of 2 MC layers and their associated FW cutoffs residing inside the plasma at low He-3 concentration. One of these layers is approaching and crossing the low-field side plasma edge when 1.8 < X[He-3] < 5%. Adopting a minimization procedure to correlate the MC positions with the plasma composition reveals that the different behaviors observed are due to contamination of the plasma. Wave modeling not only supports this interpretation but also shows that moderate concentrations of D-like species significantly alter the overall wave behavior in He-3-H plasmas. Whereas numerical modeling yields quantitative information on the heating efficiency, analytical work gives a good description of the dominant underlying wave interaction physics

Association of the SULT1A1 R213H polymorphism with colorectal cancer

1. Sulphotransferases are a superfamily of enzymes involved in both detoxification and bioactivation of endogenous and exogenous compounds. The arylsulphotransferase SULT1A1 has been implicated in a decreased activity and thermostability when the wild-type arginine at position 213 of the coding sequence is substituted by a histidine. SULT1A1 is the isoform primarily associated with the conversion of dietary N -OH arylamines to DNA binding adducts and is therefore of interest to determine whether this polymorphism is linked to colorectal cancer. 2. Genotyping, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, was performed using DNA samples of healthy control subjects (n = 402) and patients with histologically proven colorectal cancer (n = 383). Both control and test populations possessed similar frequencies for the mutant allele (32.1 and 31%, respectively; P = 0.935). Results were not altered when age and gender were considered as potential confounders in a logistic regression analysis. 3. Examination of the sulphonating ability of the two allozymes with respect to the substrates p -nitrophenol and paracetamol showed that the affinity and rate of sulphonation was unaffected by substitution of arginine to histidine at position 213 of the amino acid sequence. 4. From this study, we conclude that the SULT1A1 R213H polymorphism is not linked with colorectal cancer in this elderly Australian population