Mercury and selenium binding biomolecules in terrestrial mammals (Cervus elaphus and Sus scrofa) from a mercury exposed area

Acknowledgements The authors are grateful to Junta de Comunidades de Castilla-La Mancha (PCC-05-004-2, PAI06-0094, PCI-08-0096, PEII09-0032-5329) and the Ministerio de Economía y Competitividad (CTQ2013-48411-P) for financial support. M.J. Patiño Ropero acknowledges the Junta de Comunidades de Castilla-La Mancha for her PhD. fellowship.Peer reviewedPostprin

Rumen function and digestion parameters associated with differences between sheep in methane emissions when fed chaffed lucerne hay

An indoor experiment involving 10 rumen-cannulated Romney sheep was conducted in May and June 1998 at AgResearch Grasslands, Palmerston North, New Zealand, under restricted feeding conditions. in order to test the hypothesis that animal factors, in particular rumen fractional outflow rate (FOR) and rumen volume, have an influence on the between-sheep variation in methane (CH4) emission. Sheep were fed 2-hourly on chaffed lucerne hay. Following an acclimatization period of 21 days, the experiment lasted 16 days. Energy and nitrogen (N) balances were measured on days 1-6. Cr-EDTA marker was continuously infused into the rumen from day 9 to 16, and rumen contents emptied and sampled on days 13 and 16. Particulate and fluid FOR were estimated using feed lignin and Cr-EDTA, respectively. Daily CH, production was measured by the sulphur hexafluoride tracer technique on days 2, 5, 6, 12 and 15 of the experiment. CH4 production (g/day) was positively correlated with the pool size of organic matter (OM) in the rumen (OM pool, g) (r = 0.84, P = 0.002), OM intake (OMI, g/day) (r = 0.67, P = 0.04), and the rumen fill (g. wet digesta) (r = 0.76, P = 0.01). Multiple regression analysis showed that CH4 production was best predicted (R-2 = 0.88) as a function of OM pool and the molar % of butyrate; however, OM pool alone accounted for a large proportion (R-2 = 0.71) of the variation in CH4 production. CH4 yield (% gross energy intake, % GEI) was negatively correlated with the particulate FOR (%/h) ( r= -0.75, P = 0.01) and buffering capacity of rumen fluid (mmol HCl) (r = -0.72, P = 0.02) but positively correlated with the digestibility of cellulose (r = 0.66, P = 0.04). Multiple regression analysis showed that CH, yield was best predicted as a function of particulate FOR, OMI (g/kg liveweight(0.75)) and the molar % of butyrate (R-2 = 0.88). Particulate FOR alone explained a large proportion (R-2 = 0.57) of the variation in CH4 Yield. Particulate FOR was negatively correlated with rumen fill (r = -0.69, P = 0.03) and digestibility of cellulose (r = -0.65, P = 0.04). These results suggest that sheep with lower rumen particulate FOR (i.e. longer rumen retention times) had larger rumen fills and higher fibre digestibilities and CH4 yields. If rumen particulate FOR is to be used as a tool for CH4 mitigation, the repeatability of its relationship to CH4 emission must be assessed, preferably under grazing conditions

Persistence of differences between sheep in methane emission under generous grazing conditions

Four low and four high methane (CH4) emitters were selected from a flock of 20 Romney sheep on the basis of CH4 production rates per unit of intake, measured at grazing using the sulphur hexafluoride (SF,) tracer technique. Methane emissions from these sheep were monitored at grazing for four periods (P): October, November, January and February 1999/2000. All measurements were carried out on perennial ryegrass/white clover pasture under generous herbage allowance, and the sheep were maintained on similar pastures during non-measurement periods. The tracer technique was used for all the CH4 measurements and feed DM intake was calculated from total faecal collection and estimated DM digestibility. Data for liveweight (LW), gross energy intake (GEI) and CH4 emission were analysed using split-plot analysis of variance. In addition, a between-period rank order correlation analysis was carried out for CH4 emission data. Low CH4 emitters were heavier (P < 0.05) than the high emitters in all the periods, but they did not differ (P < 0.05) in their gross energy intakes (GEL MJ/kg LW0.75). Low and high CH4 emitters consistently maintained their initial rankings in CH4 yield (% GEI) throughout the subsequent periods and the correlation analysis of rank order for CH4 yield showed strong between-period correlation coefficients, although this was weaker in the last period. It is suggested that feeding conditions that maximize feed intake (e.g. generous allowance of good quality pasture under grazing) favour the expression and persistence of between-sheep differences in CH4 yield

The Effect of Explicit Instruction on Learning Vocabulary and Text Comprehension

The present study examined whether vocabulary intervention improves text comprehension by explicitly teaching words. The participants were institutionalized students aged between 9 and 12 years (n = 23), who completed five sessions based on solid vocabulary instruction. The semantic understanding of the taught words was measured before and after the intervention. Subsequently, they read two matched texts, one containing taught words (i.e., explicit instruction) and one without (i.e., minimal guidance instruction). The data suggest that solid vocabulary instruction significantly improved word comprehension. Specifically, they performed better in terms of the number of words learned and the amount of responses to implicit and explicit questions. It is recommended for teachers to conduct direct and explicit vocabulary interventions to improve reading comprehension in institutionalized students. Keywords: explicit teaching, reading skills, institutionalized students. Resumen El presente estudio examinó si la intervención del vocabulario mejora el conocimiento de textos enseñando explícitamente las palabras. Los participantes fueron estudiantes de 9 a 12 años en condición de institucionalización (n = 23), quienes completaron 5 sesiones basadas en instrucción de vocabulario sólido. La comprensión semántica de las palabras enseñadas se midió antes y después de la intervención. Posteriormente, leyeron 2 textos emparejados, 1 que contiene palabras enseñadas (i.e., instrucción explicita) y 1 no (i.e., instrucción con guía mínima). Los datos sugieren que la instrucción del vocabulario sólido mejoró significativamente la comprensión de palabras. Específicamente, tuvieron mejor desempeño en el número de palabras aprendidas y en la cantidad de las respuestas a las preguntas implícitas y explícitas. Se recomienda a los docentes conducir intervenciones directas y explícitas de vocabulario para mejorar la comprensión lectora en estudiantes institucionalizados. Palabras Clave: enseñanza explícita, destreza lectora, estudiantes institucionalizados

The Effect of Affirmative Action on Workers’ Outcomes

Fifty-six years after the introduction of affirmative action in employment in the U.S., there is a lack of consensus regarding the effect of this policy on workers’ careers (Holzer and Neumark, 2000). This paper contributes to fill this gap by building and analyzing a dataset that allows us to quantify the effects of affirmative action in employment on workers’ labor market outcomes. This paper circumvents prior data restrictions by constructing the first administrative database containing worker-level information (from the Longitudinal Employment Household Dynamics) as well as the federal contractor status of workers’ employers (from the Equal Employment Opportunity Commission Data and Federal Procurement Data). We estimate the causal effects of affirmative action on workers’ outcomes exploiting different features specified by the legal obligations of the regulation in a regression discontinuity setting