112 research outputs found
Same, Similar, or Something Completely Different? Calibrating Student Surveys and Classroom Observations of Teaching Quality Onto a Common Metric
Using item response theory, this study explores whether student survey and classroom observation items can be calibrated onto a common metric of teaching quality. The data comprises 269 lessons of 141 teachers that were scored on the International Comparative Analysis of Learning and Teaching (ICALT) observation instrument and the My Teacher student survey. Using Rasch model concurrent calibration, items from both instruments were calibrated onto a common oneâdimensional metric of teaching quality. Most items were found to fit the model. Challenges pertain mainly to items measuring teaching students learning strategies and differentiation. Explanations for these difficulties are discussed
Common Variants at 10 Genomic Loci Influence Hemoglobin A(1C) Levels via Glycemic and Nonglycemic Pathways
OBJECTIVE Glycated hemoglobin (HbA1c), used to monitor and diagnose diabetes, is influenced by average glycemia over a 2- to 3-month period. Genetic factors affecting expression, turnover, and abnormal glycation of hemoglobin could also be associated with increased levels of HbA1c. We aimed to identify such genetic factors and investigate the extent to which they influence diabetes classification based on HbA1c levels.
RESEARCH DESIGN AND METHODS We studied associations with HbA1c in up to 46,368 nondiabetic adults of European descent from 23 genome-wide association studies (GWAS) and 8 cohorts with de novo genotyped single nucleotide polymorphisms (SNPs). We combined studies using inverse-variance meta-analysis and tested mediation by glycemia using conditional analyses. We estimated the global effect of HbA1c loci using a multilocus risk score, and used net reclassification to estimate genetic effects on diabetes screening.
RESULTS Ten loci reached genome-wide significant association with HbA1c, including six new loci near FN3K (lead SNP/P value, rs1046896/P = 1.6 Ă 10â26), HFE (rs1800562/P = 2.6 Ă 10â20), TMPRSS6 (rs855791/P = 2.7 Ă 10â14), ANK1 (rs4737009/P = 6.1 Ă 10â12), SPTA1 (rs2779116/P = 2.8 Ă 10â9) and ATP11A/TUBGCP3 (rs7998202/P = 5.2 Ă 10â9), and four known HbA1c loci: HK1 (rs16926246/P = 3.1 Ă 10â54), MTNR1B (rs1387153/P = 4.0 Ă 10â11), GCK (rs1799884/P = 1.5 Ă 10â20) and G6PC2/ABCB11 (rs552976/P = 8.2 Ă 10â18). We show that associations with HbA1c are partly a function of hyperglycemia associated with 3 of the 10 loci (GCK, G6PC2 and MTNR1B). The seven nonglycemic loci accounted for a 0.19 (% HbA1c) difference between the extreme 10% tails of the risk score, and would reclassify âŒ2% of a general white population screened for diabetes with HbA1c.
CONCLUSIONS GWAS identified 10 genetic loci reproducibly associated with HbA1c. Six are novel and seven map to loci where rarer variants cause hereditary anemias and iron storage disorders. Common variants at these loci likely influence HbA1c levels via erythrocyte biology, and confer a small but detectable reclassification of diabetes diagnosis by HbA1c
A live weight-heart girth relationship for accurate dosing of east African shorthorn zebu cattle
The accurate estimation of livestock weights is important for many aspects of livestock management including nutrition, production and appropriate dosing of pharmaceuticals. Subtherapeutic dosing has been shown to accelerate pathogen resistance which can have subsequent widespread impacts. There are a number of published models for the prediction of live weight from morphometric measurements of cattle, but many of these models use measurements difficult to gather and include complicated age, size and gender stratification. In this paper, we use data from the Infectious Diseases of East Africa calf cohort study and additional data collected at local markets in western Kenya to develop a simple model based on heart girth circumference to predict live weight of east African shorthorn zebu (SHZ) cattle. SHZ cattle are widespread throughout eastern and southern Africa and are economically important multipurpose animals. We demonstrate model accuracy by splitting the data into training and validation subsets and comparing fitted and predicted values. The final model is weight0.262 =0.95 + 0.022 à girth which has an R2 value of 0.98 and 95 % prediction intervals that fall within the ±20 % body weight error band regarded as acceptable when dosing livestock. This model provides a highly reliable and accurate method for predicting weights of SHZ cattle using a single heart girth measurement which can be easily obtained with a tape measure in the field setting
Dynamic political contexts and power asymmetries: the cases of the Blue Nile and the Yarmouk Rivers
This paper explores the evolving patterns of hydropolitical relations in the dynamic contexts of Yarmouk and Blue Nile Rivers in comparison. The analysis aims at shedding light over the complex implications that recent political and social changes have aroused for the water disputes between Jordan and Syria on the one hand, and Ethiopia and Egypt on the other. In both basins, cooperative efforts toward the integrated management of transboundary waters have been only partially effective and largely undermined by the perpetuation of unilateral actions by riparian states. In the case studies, the lack of a basin-wide vision over the control and use of shared waters has resulted in disputes among the basin states and ultimately in an unsustainable, unfair, and unwise utilization of the resources. This paper argues that a substantive and effective integration of national water policies is unlikely to occur, unless power asymmetries are properly addressed in order to overcome the likelihood of hegemonic regimes
Benthic algal response to N and P enrichment along a pH gradient
Nutrient enrichment and its effect on benthic algal growth, community composition, and average cell size was assessed across two sites of differing pH within a single habitat. Nutrients were added using in situ substrata, which released either N, P, or no additional nutrients (controls) at each site for 21 days. Upon collection, chlorophyll and biovolume standing stocks of the attached algal microflora were measured. Chlorophyll concentration was different among all treatments, accumulating greatest on P, followed by N, and the least on C substrata (P < 0.001) and was highest at site-2 (P < 0.001), while total algal biovolume was highest on P compared to both N and C substrata (P < 0.05) and did not vary between sites. Increased growth on P substrata was due to the enhanced biovolume of filamentous green algae, although the affected taxa varied between sites. Biovolume to cell density ratios (as a measure of average cell size) were highest on P substrata over both N-enriched and control substrata (P < 0.05) and this pattern was similar between sites. Progression towards a community composed of larger cells following P enrichment observed along this pH gradient, seems to be related to the dominance of larger celled filamentous green algae. Thus, nutrients exhibited greater control on benthic algal growth than did changes in hydrogen ion concentration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42877/1/10750_2004_Article_BF00007599.pd
Animal keeping in Chalcolithic North-Central Anatolia:What can stable isotope analysis add?
Stable isotope analysis is an essential investigative technique, complementary to more traditional zooarchaeological approaches to elucidating animal keeping practices. Carbon (ÎŽ13C) and nitrogen (ÎŽ15N) stable isotope values of 132 domesticates (cattle, caprines and pigs) were evaluated to investigate one aspect of animal keeping, animal forage, at the Late Chalcolithic (mid-fourth millennium BC) site of Ăamlıbel Tarlası, which is located in north-central Anatolia. The analyses indicated that all of the domesticates had diets based predominantly on C3 plants. Pig and caprine ÎŽ13C and ÎŽ15N values were found to be statistically indistinguishable. However, cattle exhibited distinctive stable isotope values and, therefore, differences in diet from both pigs and caprines at Ăamlıbel Tarlası. This difference may relate to the distinct patterns of foraging behaviour exhibited by the domesticates. Alternatively, this diversity may result from the use of different grazing areas or from the foddering practices of the Ăamlıbel Tarlası inhabitants
Use of Heart Girth to Predict Body Weight of Working Oxen in the Ethiopian Highlands
Few studies have been conducted in sub-Saharan Africa where multiple recordings of heart girth and body weight were made for the same cattle population. In this study, monthly measurements were taken of working oxen on 24 smallholder farms in the Ethiopian highlands for 1 year. The overall yearly mean body weight of oxen across working and nonworking periods was 281 ± 37 kg. No significant differences in mean monthly body weights were observed, except for December and January compared to August (297 ± 36 and 296 ± 37, and 271 ± 35 kg, respectively, P2values for the monthly equations ranged from 0.63 to 0.87 and the R2 value for the entire year was 0.75. The single equation for the year predicted body weight of oxen as a group to within ± 27 kg of mean monthly weighbridge values, whereas for a single animal the predicted body weight was ± 37 kg of the actual weight (C.I. 95%). The single equation can be used to monitor mean body weight of the oxen population equally well across working and nonworking periods of the year
A descriptive study of work aggravated asthma
Background and Aims: Work related asthma (WRA) is one of the most frequently reported occupational lung diseases in a number of industrialised countries. A better understanding of work aggravated asthma (WAA), as well as work related new onset asthma (NOA), is needed to aid in prevention efforts. Methods: WAA and NOA in the United States were compared using cases reported to the National Institute for Occupational Safety and Health (NIOSH) from four state Sentinel Event Notification Systems for Occupational Risks (SENSOR) surveillance programmes for 1993â95. Results: A total of 210 WAA cases and 891 NOA cases were reported. WAA cases reported mineral and inorganic dusts as the most common exposure agent, as opposed to NOA cases, in which diisocyanates were reported most frequently. A similar percentage of WAA and NOA cases still experienced breathing problems at the time of the interview or had visited a hospital or emergency room for work related breathing problems. NOA cases were twice as likely to have applied for workers' compensation compared with WAA cases. However, among those who had applied for worker compensation, approximately three-fourths of both WAA and NOA cases had received awards. The services and manufacturing industrial categories together accounted for the majority of both WAA (62%) and NOA (75%) cases. The risk of WAA, measured by average annual rate, was clearly the highest in the public administration (14.2 cases/10(5)) industrial category, while the risk of NOA was increased in both the manufacturing (3.2 cases/10(5)) and public administration (2.9 cases/10(5)) categories. Conclusions: WAA cases reported many of the same adverse consequences as NOA cases. Certain industries were identified as potential targets for prevention efforts based on either the number of cases or the risk of WAA and NOA
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