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Scientists have long known that certain pesticides, industrial chemicals and heavy metals have a detrimental impact on the reproductive health of a wide range of species (including humans) by disrupting the endocrine system. As exposure to, and the effects of, ‘endocrine disrupters’ are likely to be more pronounced in wild species with a short gestation period and life-cycle we have chosen to develop non-invasive tools based upon faecal steroid analysis to monitor the reproductive status of the short-tailed field vole (Microtus agrestis). This approach is hoped to eventually provide a sensitive means of detecting environmental disturbances that could adversely affect humans, livestock and wildlife by establishing the the field vole as a terrestrial biomarker. Faecal steroid hormone analysis has already been demonstrated as being a convenient and reliable means of diagnosing reproductive state in a large range of mammalian species (including gazelle, rhino, macaque and mice), however, as of yet little is known regarding the hormonal changes that occur during pregnancy in M. agrestis.
The improvement of neonatal viability by maternal nutrition during gestation has been widely studied in numerous species. Recent investigations have explored the role of long chain omega-3 essential fatty acids (EFAs) in maternal diets during pregnancy. These are the major fatty acids, docosahexaenoic acid (DHA) in particular, in brain and nervous tissue, with specific roles in neural development and cognitive function. Studies in monogastric species have shown that supplementing maternal gestation diets with EFAs positively influences neonatal survival and growth (Rooke et al., 2001), but work in ruminant species is scarce. Previous investigations have predominantly used fish oil as the source of omega-3 EFAs but alternative, more sustainable, sources are desirable. To date, the effect of period of inclusion of EFAs in gestation diets has not been thoroughly explored. The period of rapid brain growth in the ovine foetus occurs between 10 and 6 weeks prior to birth (Turley et al., 1996). This study explored the effects of feeding an algal source of EFAs, with a high content of DHA, during different time periods on measures of lamb viability.
Actigen™ is a second generation, unique bioactive fraction derived from the outer cell wall of a specific strain of yeast, Saccharomyces cerevisiae, where it acts in the gut to bind pathogenic bacteria, preventing disease and competition for nutrients. In the current trial, 260 sows were used and fed either an unsupplemented control diet or one containing Actigen™ at 0.08% of the formulation during gestation, farrowing and lactation, to assess its impact on sow and piglet performance. Results showed significant increases in feed intake for sows fed Actigen™ pre-farrowing, but this was reversed during lactation, leading to a 7 kg saving in feed intake per animal. At birth, piglets weighed 42 g more in litters from Actigen™-fed sows compared to the control group. Weaning weight of the total litter from Actigen™ sows was significantly higher (P< 0.05) by 3.3 kg, although individual piglet weights were the same. Sows showed no significant loss in body weight during the trial, indicating that the improved piglet production was related to improved nutrient availability and perhaps Ig status of piglets due to the addition of Actigen™ in the diet.
A rapid physical vapor deposition process (PVD) utilizing a high speed rotating substrate and small substrate-to-source spacing has been used to produce bulk sheet of Ti-Al alloys in the compositional range Ti-12% Al to Ti-75% Al1 at a rate of 1–3 μm/minute. Microstructural architectures produced by the method comprise of either fully homogenous phase mixtures of nano-grains, or nanolaminated material, depending on the substrate rotational rate, with lower rotational rate producing a layered microstructure. Defect populations within the as-deposited material are characterized by TEM and SEM, and hot pressing consolidation of the as-deposited material, which retains a grain size < 1000 nm, has been investigated. While indentation hardness of α2+γ(2 phase) alloys exceeded 7 GPa, brittle failure occurred in the elastic regime at nominally lower tensile stress than that for conventionally produced alloys containing Nb and Cr as solute elements. α2+γ alloys can exhibit tensile elongations of more than 100% at 850°C with retention of fine grain size. Elevated temperature failure occurs by the formation of voids in regions of compositional variability in the composite where single phase α2-Ti3Al structure was present.
Mechanical response of interfaces between intermetallic matrices and ductile reinforcements is of considerable interest in intermetallic matrix composite design. A new approach has been developed to study crack initiation at a planar bimaterial interface by loading one of the adjoining phases in compression. A primarily Mode II stress state with different degrees of superimposed tensile and compressive loading develops at the interface as predicted by FEM analysis. This test method has been used to study NiAl/Mo and NiAl/Cr interfaces in model laminates.
We discuss some of the issues that have arisen during the development and introduction into practice of information materials for health professionals and patients that aim to promote clinical effectiveness and informed patient participation in clinical decision making.
To determine whether feeding a sustainable, algal source of docosahexaenoic acid (DHA) to sheep during late pregnancy would improve neonatal lamb vigour, 48 English mule ewes, of known conception date, were divided into four treatment groups. For the last 9 weeks of gestation, ewes received one of two dietary supplements: either a DHA-rich algal biomass providing 12 g DHA/ewe per day, or a control supplement based on vegetable oil. The four dietary treatment groups (n = 12) were: control supplement for the duration of the trial (C), DHA supplement from 9 to 6 weeks before parturition (3 week), DHA supplement from 9 to 3 weeks before parturition (6 week) and DHA supplement for the duration of the trial (9 week). Dietary supplements were fed alongside grass silage and commercial concentrate. There was a tendency for gestation length to be extended with increased duration of DHA supplementation (P = 0.08). After parturition, the concentrations of eicosapentaenoic acid (EPA) and DHA in ewe and lamb plasma and colostrum were elevated in line with increased periods of DHA supplementation. Lambs from the 6-week and 9-week groups stood significantly sooner after birth than lambs from the C group (P < 0.05). These data show that neonatal vigour may be improved by the supplementation of maternal diets with DHA-rich algal biomass and that this beneficial effect depends upon the timing and/or duration of DHA allocation.
The search for susceptibility genes for schizophrenia and severe affective disorder has been enhanced by the study of cytogenetic abnormalities that disrupt genes directly. One such gene is DISCI and there is increasing evidence that it may be an important modulator of risk of psychosis.
Previous investigations have shown lamb vigour to be improved by including long chain omega-3 fatty acids in maternal diets during late pregnancy (Capper et al., 2003; Dawson and Edgar 2005; Pickard et al., 2005). However, these trials fail to elucidate whether there is a period in late gestation when supplementing diets with omega-3s would be optimal. Omega-3 fatty acids, particularly docosahexaenoic acid (DHA), are found in high concentrations in brain and nervous tissue (Arbuckle and Innis, 1993), and are therefore required at times of neural and brain tissue growth. This study explored the effects of feeding an algal source of EFAs, with a high content of DHA, during different time periods on measures of lamb viability.
Loblolly pine trees struck by lightning offer a favorable attack and brood environment for the southern pine and Ips beetles. In central Louisiana lightning strikes reduced oleoresin exudation pressure, oleoresin flow, and relative water content of inner-bark tissue and resulted in a decrease in sucrose and an increase in reducing-sugar content of inner bark. Interspecific competition was much greater in struck trees than nonstruck trees. Among struck trees, those with highest carbohydrate levels produced the most numerous broods of the southern pine beetle.
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