28 research outputs found

    Independent and combined effects of diethylhexyl phthalate and polychlorinated biphenyl 153 on sperm quality in the human and dog

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    A temporal decline in human and dog sperm quality is thought to reflect a common environmental aetiology. This may reflect direct effects of seminal chemicals on sperm function and quality. Here we report the effects of diethylhexyl phthalate (DEHP) and polychlorinated biphenyl 153 (PCB153) on DNA fragmentation and motility in human and dog sperm. Human and dog semen was collected from registered donors (n = 9) and from stud dogs (n = 11) and incubated with PCB153 and DEHP, independently and combined, at 0x, 2x, 10x and 100x dog testis concentrations. A total of 16 treatments reflected a 4 × 4 factorial experimental design. Although exposure to DEHP and/or PCB153 alone increased DNA fragmentation and decreased motility, the scale of dose-related effects varied with the presence and relative concentrations of each chemical (DEHP.PCB interaction for: DNA fragmentation; human p < 0.001, dog p < 0.001; Motility; human p < 0.001, dog p < 0.05). In both human and dog sperm, progressive motility negatively correlated with DNA fragmentation regardless of chemical presence (Human: P < 0.0001, r = −0.36; dog P < 0.0001, r = −0.29). We conclude that DEHP and PCB153, at known tissue concentrations, induce similar effects on human and dog sperm supporting the contention of the dog as a sentinel species for human exposure

    To what extent can zero tillage lead to a reduction in greenhouse gas emissions from temperate soils?

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    Soil tillage practices have a profound influence on the physical properties of soil and the greenhouse gas (GHG) balance. However there have been very few integrated studies on the emission of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) and soil biophysical and chemical characteristics under different soil management systems. We recorded a significantly higher net global warming potential under conventional tillage systems (26–31% higher than zero tillage systems). Crucially the 3-D soil pore network, imaged using X-ray Computed Tomography, modified by tillage played a significant role in the flux of CO2 and CH4. In contrast, N2O flux was determined mainly by microbial biomass carbon and soil moisture content. Our work indicates that zero tillage could play a significant role in minimising emissions of GHGs from soils and contribute to efforts to mitigate against climate change

    Maternal fructose and/or salt intake and reproductive outcome in the rat: effects on growth, fertility, sex ratio, and birth order

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    Maternal diet can significantly skew the secondary sex ratio away from the expected value of 0.5 (proportion males), but the details of how diet may do this are unclear. Here, we altered dietary levels of salt (4% salt in the feed) and/or fructose (10% in the drinking water) of pregnant rats to model potential effects that consumption of a "Western diet" might have on maternofetal growth, development, and sex ratio. We demonstrate that excess fructose consumption before and during pregnancy lead to a marked skew in the secondary sex ratio (proportion of males, 0.60; P < 0.006). The effect was not mediated by selective developmental arrest of female embryos or influenced by fetal position in the uterine horn or sex-specific effects on sperm motility, suggesting a direct effect of glycolyzable monosaccharide on the maternal ovary and/or ovulated oocyte. Furthermore, combined excess maternal consumption of salt and fructose-sweetened beverage significantly reduced fertility, reflected as a 50% reduction in preimplantation and term litter size. In addition, we also noted birth order effects in the rat, with sequential implantation sites tending to be occupied by the same sex

    Exploring the effects of tomato extract supplementation on cognitive function during exercise and at rest

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    It has been reported that tomato (Solanum lycopersicum) fruit extracts may have beneficial effects on cognition. To assess if those effects are reproducible, cognitive function was assessed using a double-blind, randomised control trial design; 17 healthy test participants were given encapsulated tomato fruit (n=8) extract (290 mg) or a placebo control (n=9). Cognition was assessed at rest and, as exercise is known to negatively impact on cognitive function, equivalent tests were also undertaken after controlled physical exertion using the Bath University Rugby Shuttle Test (45 minutes and 90 minutes exercise). After normalisation of raw data to remove performance related error, the tomato fruit extract improved (P [less than] 0.05) normalised detection scores and detection times after 90 minutes exercise. These positive effects were specific to psychomotor function, relating to both ability and speed of response; compared to placebo controls, the supplemented group recorded scores 6.5% (P=0.02) and speeds ~17% (P=0.03) better when compared to the placebo group. A repeated measures linear mixed model (LMM) was undertaken and again significance reported (P [less than] 0.05) for overall effects of treatment (detection speeds and scores) and additionally for the identification speed. A suggestion (P [less than] 0.1) of treatment effects was observed for identification scores. LMM analysis therefore also identifies positive benefits for reaction times and visual attention after supplementation. No effect on one-card-learning (visual learning) scores or speeds was detected; also there is no evidence of any learning effect on the data. Collectively this data shows certain tomato fruit extracts have a trait specific beneficial effect on cognition

    Impact of mixed feedstock of wheat straw, willow and Miscanthus on enzymatic hydrolysis and inhibitor production after microwave hydrothermal pre-treatment in Europe

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    Lignocellulosic feedstocks for biorefinery are likely to be seasonal and the supply of feedstock to cellulosic biorefineries remains a challenge. One way to overcome this is by utilizing a mixed feedstock which facilitates the maintenance of a year-round feedstock supply. This study investigated the impact of mixing of three industrially relevant cellulosic feedstocks—wheat straw, willow and Miscanthus using two major performance indicators—sugar yield and fermentation inhibitor production. A microwave hydrothermal pre-treatment regime of 200 °C for 5 min was applied to each feedstock individually and to 1:1 (w/w) mixes and the predicted sugar yield in the mixes was compared to the observed values. All the mixes resulted in improved sugar yields with willow + Miscanthus (15.4%, p = 0.015) and wheat + willow (13.6%, p = 0.010) showing a statistically significant improvement. Saccharification kinetics, inhibitor production, impact on yeast metabolic activity and growth were compared and no adverse impacts of mixing were observed. The use of mixed feedstocks in a hot water based commercial production of biofuels is unlikely to have any adverse effects on productivity and may indeed prove beneficial

    Evaluation of progestogen supplementation for luteal phase support in fresh in vitro fertilization cycles

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    © 2019 American Society for Reproductive Medicine Objective: To evaluate the effectiveness of progestogen supplementation in improving clinical pregnancy rates in women undergoing fresh IVF cycles and to compare different routes, start times, durations, and estrogen coadministration regimen. Design: Comprehensive systematic review and meta-analysis. Setting: University. Patient(s): Women undergoing fresh IVF cycles who did and did not receive progestogen supplementation. Intervention(s): Summary odds ratios (ORs) were calculated by binomial logistic regression. Main Outcome Measure(s): Clinical pregnancy rates. Result(s): Eighty-two articles (26,726 women) were included. Clinical pregnancy rates were increased by IM (OR = 4.57), vaginal (OR = 3.34), SC (OR = 3.36), or oral (OR = 2.57) progestogen supplementation versus no treatment. The greatest benefit was observed when progestogens were supplemented IM versus vaginally (OR = 1.37). The optimal time to commence administration was between oocyte retrieval and ET (OR = 1.31), with oocyte retrieval +1 day being most beneficial. Coadministration of estrogen had no benefit (OR = 1.33), whether progestogens were coadministered vaginally or IM. Clinical pregnancy rates were equivalent when progestogen supplementation was ceased after ≤3 weeks or continued for up to 12 weeks (OR = 1.06). Conclusion(s): This broad-ranging meta-analysis highlights the need to reevaluate current clinical practice. The use of progestogens in fresh IVF cycles is substantially beneficial to clinical pregnancy. Critically, the use of IM progestogens should not be dismissed, as it yielded the greatest clinical pregnancy rates. Pregnancy success was impacted by initiation of therapy, with 1 day after oocyte retrieval being optimal. There is little evidence to support coadministration of estrogen or prolonging progestogen treatment beyond 3 weeks

    Effect of feeding system on enteric methane emissions from individual dairy cows on commercial farms

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    This study investigated the effects of feeding system on diurnal enteric methane (CH4) emissions from individual cows on commercial farms. Data were obtained from 830 cows across 12 farms, and data collated included production records, CH4 measurements (in the breath of cows using CH4 analysers at robotic milking stations for at least seven days) and diet composition. Cows received either a partial mixed ration (PMR) or a PMR with grazing. A linear mixed model was used to describe variation in CH4 emissions per individual cow and assess the effect of feeding system. Methane emissions followed a consistent diurnal pattern across both feeding systems, with emissions lowest between 05:00 and 08:59, and with a peak concentration between 17:00 and 20:59. No overall difference in emissions was found between feeding systems studied; however, differences were found in the diurnal pattern of CH4 emissions between feeding systems. The response in emissions to increasing dry matter intake was higher for cows fed PMR with grazing. This study showed that repeated spot measurements of CH4 emissions whilst cows are milked can be used to assess the effects of feeding system and potentially benchmark farms on level of emissions

    The emergent rhizosphere: imaging the development of the porous architecture at the root-soil interface

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    The rhizosphere is the zone of soil infuenced by a plant root and is critical for plant health and nutrient acquisition. All below ground resources must pass through this dynamic zone prior to their capture by plant roots. However, researching the undisturbed rhizosphere has proved very challenging. Here we compare the temporal changes to the intact rhizosphere pore structure during the emergence of a developing root system in diferent soils. High resolution X-ray Computed Tomography (CT) was used to quantify the impact of root development on soil structural change, at scales relevant to individual micro-pores and aggregates (µm). A comparison of micro-scale structural evolution in homogenously packed soils highlighted the impacts of a penetrating root system in changing the surrounding porous architecture and morphology. Results indicate the structural zone of infuence of a root can be more localised than previously reported (µm scale rather than mm scale). With time, growing roots signifcantly alter the soil physical environment in their immediate vicinity through reducing root-soil contact and crucially increasing porosity at the root-soil interface and not the converse as has often been postulated. This ‘rhizosphere pore structure’ and its impact on associated dynamics are discussed

    Effects of lameness treatment for claw horn lesions on lying behaviour in dairy cows

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    Lameness affects lying behaviour in dairy cattle, increasing total lying time and the number of lying bouts. However, there is limited information about the effect of lameness treatment on dairy cow behaviour. This study investigated the effect of four lameness treatments on lying behaviour (total lying time, number of bouts, average bout duration and laterality of lying) in dairy cows. Forty-four newly lame cows were treated randomly with one of four treatment protocols: trim only, trim + block, trim + NSAID, and trim + block + NSAID. Thirty-four non-lame control cows were matched by parity, days in milk, and farm-pen. Each cow had an accelerometer attached to the hind leg, lying behaviour data was collected over 5 days immediately after treatment and analysed using multilevel regression models. Lame cows in three of the four treatment groups demonstrated no increase in lying time compared to non-lame controls. This finding is contrary to previous work and may reflect the enrolment criteria which favoured the selection of cows with mild disease i.e. before the behavioural impacts of lameness had manifested. Only cows in the treatment group which received a therapeutic trim and a foot block saw higher lying times post treatment. As this effect was not apparent in the group which received a NSAID in addition to a trim and a foot block, we hypothesise that this effect is caused by discomfort associated with the block. Where foot blocks are administered as part of treatment protocols, we propose that NSAIDs should be administered concurrently to alleviate the behavioural changes and likely discomfort associated with this treatment

    Excess maternal salt intake produces sex-specific hypertension in offspring: putative roles for kidney and gastrointestinal sodium handling.

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    Hypertension is common and contributes, via cardiovascular disease, towards a large proportion of adult deaths in the Western World. High salt intake leads to high blood pressure, even when occurring prior to birth - a mechanism purported to reside in altered kidney development and later function. Using a combination of in vitro and in vivo approaches we tested whether increased maternal salt intake influences fetal kidney development to render the adult individual more susceptible to salt retention and hypertension. We found that salt-loaded pregnant rat dams were hypernatraemic at day 20 gestation (147±5 vs. 128±5 mmoles/L). Increased extracellular salt impeded murine kidney development in vitro, but had little effect in vivo. Kidneys of the adult offspring had few structural or functional abnormalities, but male and female offspring were hypernatraemic (166±4 vs. 149±2 mmoles/L), with a marked increase in plasma corticosterone (e.g. male offspring; 11.9 [9.3-14.8] vs. 2.8 [2.0-8.3] nmol/L median [IQR]). Furthermore, adult male, but not female, offspring had higher mean arterial blood pressure (effect size, +16 [9-21] mm Hg; mean [95% C.I.]. With no clear indication that the kidneys of salt-exposed offspring retained more sodium per se, we conducted a preliminary investigation of their gastrointestinal electrolyte handling and found increased expression of proximal colon solute carrier family 9 (sodium/hydrogen exchanger), member 3 (SLC9A3) together with altered faecal characteristics and electrolyte handling, relative to control offspring. On the basis of these data we suggest that excess salt exposure, via maternal diet, at a vulnerable period of brain and gut development in the rat neonate lays the foundation for sustained increases in blood pressure later in life. Hence, our evidence further supports the argument that excess dietary salt should be avoided per se, particularly in the range of foods consumed by physiologically immature young
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