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A large proportion of broiler chickens suffer from lameness euphemistically called ‘leg weakness’. In a survey of commercial, intensively reared broilers, 90% had a detectable gait abnormality and 26% suffered an abnormality of sufficient severity for their welfare to be compromised (Kestin et al., 1992). It is assumed that leg weakness is painful but there is little direct evidence of this. Chickens have been shown to be able to select an adequate protein diet from a choice of two or three foods which are individually inadequate (Forbes and Shariatmadari, 1994). Broiler chickens showed a significant preference for food of the colour which was paired with ascorbic acid supplementation when the requirement for ascorbic acid was increased by heat stress (Kutlu and Forbes, 1993).
Data on the depth distribution of the major atmospheric gases and the abundance of gaseous 12CO2, 13CO2, and 14CO2 in the subsoil unsaturated zone have been obtained from several sites in the western Great Plains of the United States. Sample profiles range from land surface to depths of 50m. Although each site must be considered on an individual basis, several general statements can be made regarding the profiles. 1) Diffusion of these gaseous molecules through the unsaturated zone is an important transport mechanism. 2) As predicted by diffusion theory, depth profiles of the various isotopic species of CO2 differ substantially from one another, depending on individual sources and sinks such as root respiration and oxidation of organic carbon at depth. 3) In general, post-bomb (> 100% modern) 14C activities are not observed in the deep unsaturated zone, in contrast to diffusion model predictions. 4) In spite of generally decreasing 14C activities with depth, absolute partial pressures of 14CO2 in the subsoil unsaturated zone are 1–2 orders of magnitude higher than the partial pressure of 14CO2 in the atmosphere.
Soil gas samples were obtained from the unsaturated zone at eight sites in the Great Plains. Three of these sites were sampled extensively for gas composition and carbon isotopes. Sampling equipment consisted of a nest of gas probes vertically spaced by roughly 3m at most sites, generally approaching the water table. Water wells, 10cm in diameter, were screened in the topmost layer groundwater. Inverted cattle tanks were used to collect CO2 samples from the soil surface. The major gas components were analyzed with emphasis on CO2, δ 13C, and 14C measurements. The same components were studied in groundwater samples. Higher than atmospheric CO2 concentrations were found in all soil samples. Root respiration and oxidation of organic matter were sources for the additional CO2. When lignite was present in the unsaturated zone, gaseous oxygen reacted almost completely, and CO2 levels rose to 19%. Near the surface, annual cycles in total CO2, δ 13C, and 14C were observed. 14C activities were close to present post-bomb levels at the surface and generally declined with depth. At some sites, oxidation of lignite caused decline of 14C levels to 1 or 2% of their surface value at 8m depth. Without lignite, the 14C activity remained above 50% at all depths. Concentrations of total carbon and its isotopes in ground water remained very stable throughout the study. This implies that geochemical processes in the aquifer vary on time scales longer than the seasonal effects observed in the near-surface unsaturated zone.
Several studies demonstrating that central line–associated bloodstream infections (CLABSIs) are preventable prompted a national initiative to reduce the incidence of these infections.
We conducted a collaborative cohort study to evaluate the impact of the national “On the CUSP: Stop BSI” program on CLABSI rates among participating adult intensive care units (ICUs). The program goal was to achieve a unit-level mean CLABSI rate of less than 1 case per 1,000 catheter-days using standardized definitions from the National Healthcare Safety Network. Multilevel Poisson regression modeling compared infection rates before, during, and up to 18 months after the intervention was implemented.
A total of 1,071 ICUs from 44 states, the District of Columbia, and Puerto Rico, reporting 27,153 ICU-months and 4,454,324 catheter-days of data, were included in the analysis. The overall mean CLABSI rate significantly decreased from 1.96 cases per 1,000 catheter-days at baseline to 1.15 at 16–18 months after implementation. CLABSI rates decreased during all observation periods compared with baseline, with adjusted incidence rate ratios steadily decreasing to 0.57 (95% confidence intervals, 0.50–0.65) at 16–18 months after implementation.
Coincident with the implementation of the national “On the CUSP: Stop BSI” program was a significant and sustained decrease in CLABSIs among a large and diverse cohort of ICUs, demonstrating an overall 43% decrease and suggesting the majority of ICUs in the United States can achieve additional reductions in CLABSI rates.
Discrimination against people with severe mental illness is an international problem. It is associated with reduced social contact and hinders recovery. This paper aims to evaluate if experienced or anticipated discrimination is associated with social capital, a known correlate of mental health.
Data from the annual viewpoint cross-sectional survey of people with severe mental illness (n = 1016) were analysed. Exploratory univariate analysis was used to identify correlates of social capital in the sample, which were then evaluated in linear regression models. Additional hypotheses were tested using t tests.
Experienced discrimination made a modest contribution to the explained variance of social capital. Experienced discrimination from friends and immediate family was associated with reduced access to social capital from these groups, but this was not found for wider family, neighbours or mental health staff. Experience of discrimination in finding or keeping a job was also associated with reduced access to social capital.
Further longitudinal research is needed to determine how resources within people's networks can help to build resilience, which reduces the harmful effect of discrimination on mental health.
In Guatemala prior to control initiatives, the main vectors of Trypanosoma cruzi, the causative agent of Chagas disease, were Rhodnius prolixus and Triatoma dimidiata. This study conducted in 2006 in the department of Chiquimula recorded a high level of T. dimidiata infestation and an absence of R. prolixus in all surveyed communities. In Guatemala, the presence of T. dimidiata as domestic, peridomestic and sylvatic populations results in control difficulties as houses are re-infested from the surrounding environment. Entomological surveys, the current method used to select houses in need of control efforts, are labour intensive and time consuming. A time- and cost-effective way to prioritize houses for evaluation and subsequent treatment is the stratification of houses based on the risk of triatomine infestation. In the present study, 17 anthropogenic risk factors were evaluated for associations with house infestation of T. dimidiata including: wall, floor and roof type. There was an increased likelihood of domestic infestation with T. dimidiata associated with the presence of dirt floors (18/29; OR 8.075, 95% CI 2.13–30.6), uncoated bajareque walls (12/17; OR 4.80, 95% CI 1.35–17.1) and triatomine-like faeces on walls (16/26; OR 3.89, 95% CI 1.19–12.7). These factors could be used to target control of T. dimidiata to communities with an increased risk of being infested.
This paper reports the events at NCSU leading up to and including those of June 5, 1997 which produced the first demonstration of a nitride laser diode on silicon carbide – and the very first nitride laser demonstration outside of Japan. All of the laser diode samples tested at NCSU were designed, grown, and fabricated into cleaved cavity test structures at Cree Research. Laser testing at NCSU consisted of spectral emission versus current measurements, light output power versus current (L-I) measurement, and light output polarization measurements versus current. The first successful laser on silicon carbide emitted at 402.6 nm. Subsequently, lasers displaying outputs ranging from 402.6 to 430.2 have been successfully tested at NCSU.
In ruminants and humans, the majority of whole body glucose utilization is not mediated by insulin. However, while in man most non-insulin-mediated glucose utilization (NIMGU) occurs in the brain, in ruminants the locations of NIMGU remain less well defined. As fasting would be expected to limit NIMGU to what would be regarded as an essential minimum, two studies were performed to establish the contribution of NIMGU to total glucose metabolism in fed and fasted sheep. Each study used four adult castrated male sheep. In study 1, a primed continuous infusion of U- [13C] glucose was begun at time 0 and continued for 7 h. After 3 h of isotope infusion (basal period) somatostatin (0•417 µg/kg per min; SS) was administered for 4 h, either alone (SS-only) or together with insulin (1•0 mU/kg per min; SS + insulin) with normal glucose to maintain euglycaemia for 2 h. Normal glucose was then infused for both the SS-only and SS + insulin treatments to induce and maintain hyperglycaemia over the final 2 h of the experiment. In study 2, fed or 72-h fasted sheep were infused with 6-[3H] glucose from time 0 for 8 h, with SS infusion starting at 3 h and continuing for 5 h. After 3 h of SS infusion, glucose was infused to induce and maintain hyperglycaemia. In both studies SS infusion inhibited insulin secretion, however in study 2, SS in fed sheep caused hyperglycaemia; this effect was not significant in the fasted animals. The rate of glucose utilization was reduced by SS-only as it eliminated insulin mediated glucose uptake (IMGU); under such conditions whole body glucose disposal should be NIMGU. In fed sheep, average NIMGU levels represented between proportionately 0•61 and 0•67 of the basal glucose metabolic clearance rate. During the infusion of SS + insulin in fed sheep, NIMGU fell to 0•34 during euglycaemia and 0•33 during hyperglycaemia, as the infused insulin caused IMGU to predominate. In fasted sheep the absolute rates of both IMGU and NIMGU were reduced, though NIMGU as a proportion of total turn-over (IMGU + NIMGU) increased to 0•88 of glucose metabolic clearance. Calculations suggest that, in contrast to man, only a minor proportion of NIMGU is utilized by the brain and central nervous system in fed or fasted sheep. It is suggested that skeletal muscle and the gastro-intestinal tract may make a major contribution to NIMGU, even in fasted sheep.
The hyperinsulinaemic euglycaemic insulin clamp technique was used to compare insulin sensitivity in lactating ewes at two levels of feeding. Clamps were performed at two (restricted intake) or three (ad libitum intake) stages of lactation and also 30 d after drying off. Dose response curves for insulin were constructed using the glucose metabolic clearance rate (MCR) as the measure of glucose metabolism and these were statistically compared between stages of lactation within the feeding levels, and also between feeding regimes. Animals on a restricted feed intake showed a weight loss throughout lactation, coupled with a lower insulin sensitivity, as measured by the ED50 (concentration of insulin required to produce a half maximal increase in MCR), while those on ad libitum feeding showed a weight gain and a decreased insulin sensitivity in the dry period. Endogenous glucose production was less sensitive to inhibition by insulin in the animals subjected to restricted food intake, compared with those on the ad libitum regime, which suggested a major role for the plane of nutrition in adjusting the homeorhetic control of metabolism during lactation.