4,333 research outputs found
Designing and Conducting Experiments for Range Beef Cows
Designing and conducting effective research for range beef systems involves analysis of intended application of the results, identification of factors affecting variation, and selection of appropriate research methods so that precise inferences can be made. Variances associated with time, location, animal, and error in grazing research can be high. Variation due to treatment Ă location and treatment Ă time interactions is reduced by increasing the number of locations and periods tested. Random error is reduced by increasing the total number of observations. Animals, pastures, and weather are significant sources of variation in grazing studies. Factors that influence nutrient requirements or nutrient intake of cows are potential sources of variation. Amount and quality of herbage produced are highly variable within and among years and are closely related to the amount and pattern of precipitation. Vegetative measurements (e.g., cover or standing biomass) should be planned as a step in developing experimental designs and to aid in experimental layout and interpretation of the data. Vegetation sampling should be less intensive and largely descriptive in large study areas when the objectives are to measure a livestock production response and vegetation responses are considered incidental. As the priority of the objectives moves toward emphasizing plant response and the size of the study area declines, the intensity of sampling on a land unit basis increases and the need for precision increases. Generally, multiple years of study are required to address between-year variances. Experimental units and replication are key to effective experimentation. Without replication in space and(or) time, there would be no estimate of experimental error. In supplementation studies on range, experimental units are generally animals, pastures, or ranches. Animal, pasture, and ranch have advantages and disadvantages as experimental units. The advantages and disadvantages are related to hypothesis, objectives, inference, resources, number of animals, and number of treatments. When economic evaluations are part of systems research, economists should be involved in planning the experiment and formulating hypotheses. Hypotheses and interpretation of biological data may be different than for economic data. Costs need to be estimated for correct unit of output, and cost alone may be insufficient to properly rank the economic outcomes of the research
Effect of Summer Grazing on Crude Protein and Digestibility of Winter Diets of Cattle in the Nebraska Sandhills
Twenty-one pastures (three pastures/ treatment) were used in a two-year study to determine the effects of summer grazing on winter diet quality of Sandhills range. Summer grazing treatments consisted of no summer grazing (control) and June or July grazing at three stocking rates. After summer grazing, pastures were then diet sampled using esophageally fistulated cows in November, January and March following summer treatments. Year and sampling date had a significant effect on CP and IVDMD of winter range diets, whereas summer grazing treatments did not have a large impact
Derived neutrophil lymphocyte ratio is predictive of survival from intermittent therapy in advanced colorectal cancer: a post hoc analysis of the MRC COIN study
BACKGROUND: The phase III COntinuous or INtermittent (COIN) trial failed to show non-inferiority of intermittent compared with continuous chemotherapy for advanced colorectal cancer in overall survival (OS). The present analysis evaluated whether the derived neutrophil to lymphocyte ratio (dNLR) could predict the effect of intermittent vs continuous chemotherapy on OS in patients with advanced colorectal cancer. METHODS: A post hoc exploratory analysis of COIN arms A and C was performed. Landmark analysis was conducted on all patients with available WBC and neutrophils data. The dNLR was calculated using a formula which has previously demonstrated predictive power in cancer patients: dNLR=ANC/(WBCâANC). A high dNLR was defined using a cut-off value of ⊞2.22. Derived neutrophil to lymphocyte ratio was then correlated with clinical outcomes. Survival curves were generated based on dNLR using the KaplanâMeier method. Comparison between groups was performed using Cox regression. RESULTS: A total of 1630 patients were assigned to the continuous (N=815) or intermittent (N=815) arms. There was a strong association between dNLR level and OS. The median survival times in the ITT population were 18.6 months and 12.5 months for patients with low and high dNLR, respectively (HR=1.70; 95% CI=1.52â1.90; P<0.001). The estimate of the hazard ratio did not alter substantially (HR=1.54) after adjusting for treatment, tumour status, number of metastatic sites, alkaline phosphate and platelet count. CONCLUSIONS: Derived neutrophil to lymphocyte ratio is strongly prognostic for survival in the COIN intermittent vs continuous treatment arms. Derived neutrophil to lymphocyte ratio does not predict for detrimental survival in patients treated with intermittent therapy
1934: Abilene Christian College Bible Lectures - Full Text
INTRODUCTION
The theme for the Lectures for 1934, âThe New Testament Church in History,â is a very timely one and follows naturally the theme of the 1933 Lectures, âThe Church We Read About in the New Testament.â There is no subject that is so vital in our work as Christians today as a proper understanding of the great spiritual kingdom of our Savior, the church which was built by Jesus Christ. It is a hard lesson to teach because all people are so dull of hearing concerning things spiritual. Just as Nicodemus marveled when the Christ told him of the spiritual kingdom so do people today wonder and marvel when they are told that there is only one great church, the spiritual kingdom of our Lord and Savior Jesus Christ, and that all the saved of earth belong to that church and that belonging to anything else profits little, and is unnecessary. Not only are numbers of denominational churches and people who have no religious affiliation ignorant of the true meaning of the church, but even those who claim to be members of the one body are lacking in understanding concerning the kingdom of Christ. It is therefore the purpose of the Abilene College Lectures last year, this year and next year to arouse a greater interest in the study and the teaching of this very vital matter. In this particular volume much valuable information is brought together on the trials and struggles of the church from its foundations to the present. The speakers have made careful preparation on their subjects and have given lessons that should prove helpful to all who desire to have a better understanding of the church. Our prayer is that these Lectures may be read by many and that they may do much good in the name of the Christ.
Jas. F. Cox,President, Abilene Christian College.
Nov. 6, 1934
A low-voltage activated, transient calcium current is responsible for the time-dependent depolarizing inward rectification of rat neocortical neurons in vitro
Intracellular recordings were obtained from rat neocortical neurons in vitro. The current-voltage-relationship of the neuronal membrane was investigated using current- and single-electrode-voltage-clamp techniques. Within the potential range up to 25 mV positive to the resting membrane potential (RMP: â75 to â80 mV) the steady state slope resistance increased with depolarization (i.e. steady state inward rectification in depolarizing direction). Replacement of extracellular NaCl with an equimolar amount of choline chloride resulted in the conversion of the steady state inward rectification to an outward rectification, suggesting the presence of a voltage-dependent, persistent sodium current which generated the steady state inward rectification of these neurons. Intracellularly injected outward current pulses with just subthreshold intensities elicited a transient depolarizing potential which invariably triggered the first action potential upon an increase in current strength. Single-electrode-voltage-clamp measurements reveled that this depolarizing potential was produced by a transient calcium current activated at membrane potentials 15â20 mV positive to the RMP and that this current was responsible for the time-dependent increase in the magnitude of the inward rectification in depolarizing direction in rat neocortical neurons. It may be that, together with the persistent sodium current, this calcium current regulates the excitability of these neurons via the adjustment of the action potential threshold
High-resolution mass models of dwarf galaxies from LITTLE THINGS
We present high-resolution rotation curves and mass models of 26 dwarf galaxies from LITTLE THINGS. LITTLE THINGS is a high-resolution Very Large Array HI survey for nearby dwarf galaxies in the local volume within 11 Mpc. The rotation curves of the sample galaxies derived in a homogeneous and consistent manner are combined with Spitzer archival 3.6 micron and ancillary optical U, B, and V images to construct mass models of the galaxies. We decompose the rotation curves in terms of the dynamical contributions by baryons and dark matter halos, and compare the latter with those of dwarf galaxies from THINGS as well as Lambda CDM SPH simulations in which the effect of baryonic feedback processes is included. Being generally consistent with THINGS and simulated dwarf galaxies, most of the LITTLE THINGS sample galaxies show a linear increase of the rotation curve in their inner regions, which gives shallower logarithmic inner slopes alpha of their dark matter density profiles. The mean value of the slopes of the 26 LITTLE THINGS dwarf galaxies is alpha =-0.32 +/- 0.24 which is in accordance with the previous results found for low surface brightness galaxies (alpha = -0.2 +/- 0.2) as well as the seven THINGS dwarf galaxies (alpha =-0.29 +/- 0.07). However, this significantly deviates from the cusp-like dark matter distribution predicted by dark-matter-only Lambda CDM simulations. Instead our results are more in line with the shallower slopes found in the Lambda CDM SPH simulations of dwarf galaxies in which the effect of baryonic feedback processes is included. In addition, we discuss the central dark matter distribution of DDO 210 whose stellar mass is relatively low in our sample to examine the scenario of inefficient supernova feedback in low mass dwarf galaxies predicted from recent Lambda SPH simulations of dwarf galaxies where central cusps still remain.Peer reviewe
Class I major histocompatibility complexes loaded by a periodate trigger
Class I major histocompatibility complexes (MHCs) present peptide ligands on the cell surface for recognition by appropriate cytotoxic T cells. The unstable nature of unliganded MHC necessitates the production of recombinant class I complexes through in vitro refolding reactions in the presence of an added excess of peptides. This strategy is not amenable to high-throughput production of vast collections of class I complexes. To address this issue, we recently designed photocaged MHC ligands that can be cleaved by a UV light trigger in the MHC bound state under conditions that do not affect the integrity of the MHC structure. The results obtained with photocaged MHC ligands demonstrate that conditional MHC ligands can form a generally applicable concept for the creation of defined peptideâMHCs. However, the use of UV exposure to mediate ligand exchange is unsuited for a number of applications, due to the lack of UV penetration through cell culture systems and due to the transfer of heat upon UV irradiation, which can induce evaporation. To overcome these limitations, here, we provide proof-of-concept for the generation of defined peptideâMHCs by chemical trigger-induced ligand exchange. The crystal structure of the MHC with the novel chemosensitive ligand showcases that the ligand occupies the expected binding site, in a conformation where the hydroxyl groups should be reactive to periodate. We proceed to validate this technology by producing peptideâMHCs that can be used for T cell detection. The methodology that we describe here should allow loading of MHCs with defined peptides in cell culture devices, thereby permitting antigen-specific T cell expansion and purification for cell therapy. In addition, this technology will be useful to develop miniaturized assay systems for performing high-throughput screens for natural and unnatural MHC ligands
Intervention effects and long-term changes in physical activity and cardiometabolic outcomes among children at risk of noncommunicable diseases in South Africa: a cluster-randomized controlled trial and follow-up analysis
INTRODUCTION: Risk factors for noncommunicable diseases such as insufficient physical activity (PA), overweight or hypertension are becoming increasingly predominant among children globally. While school-based interventions are promising preventive strategies, evidence of their long-term effectiveness, especially among vulnerable populations, is scarce. We aim to assess the short-term effects of the physical and health KaziKidz intervention on cardiometabolic risk factors and the long-term, pre-and post-COVID-19 pandemic changes thereof in high-risk children from marginalized communities. METHODS: The intervention was tested in a cluster-randomized controlled trial between January and October 2019 in eight primary schools near Gqeberha, South Africa. Children with overweight, elevated blood pressure, pre-diabetes, and/or borderline dyslipidemia were identified and re-assessed 2 years post-intervention. Study outcomes included accelerometry-measured PA (MVPA), body mass index (BMI), mean arterial pressure (MAP), glucose (HbA1c), and lipid levels (TC to HDL ratio). We conducted mixed regression analyses to assess intervention effects by cardiometabolic risk profile, and Wilcoxon signed-rank tests to evaluate longitudinal changes in the high-risk subpopulation. RESULTS: We found a significant intervention effect on MVPA during school hours for physically inactive children, and among active as well as inactive girls. In contrast, the intervention lowered HbA1c and TC to HDL ratio only in children with glucose or lipid values within the norm, respectively. At follow-up, the intervention effects were not maintained in at-risk children, who showed a decline in MVPA, and an increase in BMI-for-age, MAP, HbA1c and TC to HDL ratio. CONCLUSION: We conclude that schools are key settings in which to promote PA and improve health; however, structural changes are necessary to ensure that effective interventions reach marginalized school populations and achieve sustainable impact
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