38 research outputs found

    Fatigue related impairments in oculomotor control are prevented by caffeine

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    Strenuous exercise can result in an inability of the central nervous system to drive skeletal muscle e ectively, a phenomenon known as central fatigue. The impact of central fatigue on the oculomotor system is currently unexplored. Fatigue that originates in the central nervous system may be related to perturbations in the synthesis and metabolism of several neurotransmitters. In this study we examine central fatigue in the oculomotor system after prolonged exercise. The involvement of central neurotransmission was explored by administering ca eine during exercise. Within a double- blind, randomized, repeated measures, crossover design, 11 cyclists consumed a placebo or ca eine solution during 180 min of stationary cycling. Saccadic eye movements were measured using infra-red oculography. Exercise decreased saccade velocity by 8% (placebo trial). This e ect was reversed by ca eine, whereby velocity was increased by 11% after exercise. A non oculomotor perceptual task (global motion processing) was una ected by exercise. The human oculomotor system is impaired by strenuous exercise of the locomotor system. Ca eine exerts a protective e ect on oculomotor control, which could be related to up-regulated central neurotransmission. In addition, cortical processes supporting global motion perception appear to be robust to fatigue

    Opportunities and challenges in the use of personal health data for health research

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    Objective: Understand barriers to the use of personal health data (PHD) in research from the perspective of three stakeholder groups: early adopter individuals who track data about their health, researchers who may use PHD as part of their research, and companies that market self-tracking devices, apps or services, and aggregate and manage the data that are generated. Materials and Methods: A targeted convenience sample of 465 individuals and 134 researchers completed an extensive online survey. Thirty-five hourlong semi-structured qualitative interviews were conducted with a subset of 11 individuals and 9 researchers, as well as 15 company/key informants. Results: Challenges to the use of PHD for research were identified in six areas: data ownership; data access for research; privacy; informed consent and ethics; research methods and data quality; and the unpredictable nature of the rapidly evolving ecosystem of devices, apps, and other services that leave “digital footprints.” Individuals reported willingness to anonymously share PHD if it would be used to advance research for the good of the public. Researchers were enthusiastic about using PHD for research, but noted barriers related to intellectual property, licensing, and the need for legal agreements with companies. Companies were interested in research but stressed that their first priority was maintaining customer relationships. Conclusion: Although challenges exist in leveraging PHD for research, there are many opportunities for stakeholder engagement, and experimentation with these data is already taking place. These early examples foreshadow a much larger set of activities with the potential to positively transform how health research is conducted

    Effect of castration and age at slaughter on sensory perception of lamb meat

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    peer-reviewedThis study assessed the effect of castration and slaughter age (196–385 days old) on sensory quality of lamb meat from two sheep breeds (Scottish Blackface, SB; Texel x Scottish Blackface, TxSB). Results obtained using a trained sensory panel showed small but statistically significant differences due to castration, with rams having higher scores for Intensity of Lamb Aroma, Animal Smell/Farm Smell, Woolly Aroma, Rancid Aroma, Manure/Faecal Aroma, Sweaty Aroma and Off-flavours. SB lamb had higher scores for Intensity of Lamb Aroma, Lamb Flavour, Lamb Aftertaste, Tenderness and Juiciness. Age effects on sensory attributes were not linear and significant age × gender interactions were observed. The number of samples considered “extreme” in undesirable flavour attributes was higher among rams and T × SB animals. The impact of the sensory differences on consumer acceptability of lamb remains to be established

    Effects of castration and slaughter age on the fatty acid composition of ovine muscle and adipose tissue from two breeds

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    peer-reviewedFatty acids (g/100 g total fatty acids) in M. longissimus thoracis et lumborum (LTL) and total branched chain fatty acids (μg/g fat) in subcutaneous adipose tissue (SAT) of rams and castrates from Scottish Blackface (SB) or Texel × Scottish Blackface (T × SB) lambs, slaughtered at mean ages of 196, 242, 293, 344 or 385 days were determined. Lambs were fed pasture prior to a 36-day finishing period on a barley/maize-based concentrate ration. The intramuscular fat content (IMF; %) was higher (P < 0.001) in castrates than in rams and in SB compared to T × SB lambs (P < 0.001). The proportions of c9-C18:1 and total monounsaturated fatty acids (MUFA) were higher (P < 0.001) in LTL of castrates than rams. The proportions of C18:2n-6 and total n-6 polyunsaturated fatty acids (PUFA) were lower (P = 0.001) in LTL of castrates compared to rams related to differences in IMF content. The proportions of C14:0, C16:0, c9-C18:1 and total MUFA were higher (P < 0.05), while the proportions of C18:2n-6, C20:4n-6, C20:5n-3, total PUFA, n-6 and n-3 PUFA were lower (P < 0.05), in SB than in T × SB lambs, which was related to differences in IMF content. There was a higher (P < 0.001) proportion of conjugated linoleic acid (CLA) c9,t11-C18:2 in LTL from SB compared to T × SB. The effects of slaughter age on the proportions of fatty acids in LTL did not show a clear trend. The concentration of 4-methylnonanoic acid was higher (P = 0.002) in SAT of rams than castrates, particularly in older lambs. Despite the differences in the muscle fatty acid composition due to gender, slaughter age or breed of lambs, the ratio of n-6/n-3 PUFA (≤3.11) was within the dietary recommendation of <4.0 for human health

    Effect of forage to concentrate ratio and duration of feeding on growth and feed conversion efficiency of male lambs

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    peer-reviewedRations (dry matter basis) for spring born male lambs consisting of concentrates ad libitum (CON), 50:50 (50% concentrate:50% forage) and forage ad libitum (FORG) were evaluated across feeding periods of 3 durations (36 d, 54 d and 72 d). Lambs on CON diets were offered ad libitum access to concentrate along with 400g of fresh weight silage (daily), while 50:50 diets were offered 0.9 kg and 3.0 kg of concentrate and silage, respectively. Lambs on FORG were offered ad libitum access to 25.5% dry matter silage. These rations were fed to 99 spring born male Texel cross Scottish Blackface lambs which were assigned to a 3 × 3 factorial arrangement. Lambs were slaughtered following completion of their respective treatments. Lambs fed CON diets had greater ADG, FCE, and carcass weight (P < 0.001) and carcasses with greater conformation score (P < 0.001) than lambs fed 50:50 or FORG diets. Duration of feeding had no effect on production variables across all three concentrate inclusion levels. It was concluded that the inclusion of concentrates is needed to adequately finish lambs fed indoors. Feeding lamb’s 50:50 diets resulted in modest responses and may be a viable option for finishing lambs or to maintain growth in lambs when the cost of concentrate feed is high relative to the financial return on the lamb meat

    Effect of breed and castration on production and carcass traits of male lambs following an intensive finishing period

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    peer-reviewedThe practice of crossbreeding using a terminal sire and the use of intact rather than castrated animals has the potential to increase the productivity of lambs produced from the hill sheep sector. The objective of this study was to compare the production and carcass characteristics of purebred Scottish Blackface (SB) and Texel cross Scottish Blackface (TXSB) ram and wether lambs fed on a concentrate diet and slaughtered at different ages. Two hundred spring born male lambs (average birth age ±SD 9.53 d) were assigned to a 2 × 2 factorial arrangement with two breeds SB (n=100) and TXSB (n=100)) and two sexes (wether: n=100 and ram: n=100)). Lambs were harvested following a 36 d ad libitum concentrate indoor finishing period. The study was carried out over five harvest batches between October and April. The mean ages of the lambs at harvest (n = 40, 20 TXSB and 20 SB lambs) in October, November, January, March and April were 196, 242, 293, 344 and 385 days, respectively The TXSB lambs were heavier at slaughter than SB lambs (P < 0.001) and ram lambs were heavier at slaughter than wether lambs (P < 0.01). Improved average daily gain (ADG) (P < 0.001), lower feed conversion ratio (FCR) (which was calculated by dividing total feed intake by total weight gain) (P < 0.001) and higher feed intake (P < 0.05) were recorded in TXSB lambs with consistency across the five harvest time points. Rams had greater ADG (P < 0.001) and FCR (P < 0.05) compared to wether lambs and no differences were observed between sexes for feed intake. The TXSB (P < 0.001) lambs had higher (P < 0.001) dressing percentages compared to SB while wether lambs had greater dressing percentages compared to rams. The TXSB lambs had heavier carcass weights (P < 0.001) with higher conformation grades (P < 0.001) and less fat cover (P < 0.001) than SB lambs while ram lambs had heavier (P < 0.001) carcasses than wether lambs. There was greater fat cover on the loin muscles of SB (P < 0.001) and wether (P < 0.001) lambs compared to TXSB and ram lambs, respectively. The results from this study suggest that TXSB lamb’s offer hill sheep farmers a potential strategy for improved lamb production efficiency, while ram lambs offer lamb finishers increased growth rates, higher FCR and produce a more desirable carcass than do wether lambs

    Effect of finishing diet and duration on the sensory quality and volatile profile of lamb meat

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    peer-reviewedAnimal production factors can affect the sensory quality of lamb meat. The study investigated the effect of diet composition and duration of consumption on the proximate analysis, volatile profile and sensory quality of lamb meat. Ninety-nine male Texel × Scottish Blackface lambs were raised at pasture for 10 months before being assigned in groups of 11 to one of the following treatments: 100% Silage (S) for 36 (S36), 54 (S54) or 72 (S72) days; 50% Silage - 50% Concentrate (SC) for 36 (SC36), 54 (SC54) or 72 (SC72) days; 100% Concentrate (C) for 36 (C36) or 54 (C54) or 72 (C72) days. A trained sensory panel found Intensity of Lamb Aroma, Dry Aftertaste and Astringent Aftertaste to be higher in meat from lambs on the concentrate diet. Discriminant analysis showed that the volatile profile enabled discrimination of lamb based on dietary treatment but the volatile differences were insufficient to impact highly on sensory quality. Muscle from animals in the S54 group had higher Manure/Faecal Aroma and Woolly Aroma than the SC54 and C54 groups, possibly related to higher levels of indole and skatole. Further research is required to establish if these small differences would influence consumer acceptability.The financial support of the Irish Department of Agriculture, Food and the Marine (project 11/SF/310) and of the Teagasc Walsh Fellowship Programme (award 2013058) is gratefully acknowledged

    PDE8 Regulates Rapid Teff Cell Adhesion and Proliferation Independent of ICER

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    BACKGROUND: Abolishing the inhibitory signal of intracellular cAMP by phosphodiesterases (PDEs) is a prerequisite for effector T (Teff) cell function. While PDE4 plays a prominent role, its control of cAMP levels in Teff cells is not exclusive. T cell activation has been shown to induce PDE8, a PDE isoform with 40- to 100-fold greater affinity for cAMP than PDE4. Thus, we postulated that PDE8 is an important regulator of Teff cell functions. METHODOLOGY/PRINCIPAL FINDINGS: We found that Teff cells express PDE8 in vivo. Inhibition of PDE8 by the PDE inhibitor dipyridamole (DP) activates cAMP signaling and suppresses two major integrins involved in Teff cell adhesion. Accordingly, DP as well as the novel PDE8-selective inhibitor PF-4957325-00 suppress firm attachment of Teff cells to endothelial cells. Analysis of downstream signaling shows that DP suppresses proliferation and cytokine expression of Teff cells from Crem-/- mice lacking the inducible cAMP early repressor (ICER). Importantly, endothelial cells also express PDE8. DP treatment decreases vascular adhesion molecule and chemokine expression, while upregulating the tight junction molecule claudin-5. In vivo, DP reduces CXCL12 gene expression as determined by in situ probing of the mouse microvasculature by cell-selective laser-capture microdissection. CONCLUSION/SIGNIFICANCE: Collectively, our data identify PDE8 as a novel target for suppression of Teff cell functions, including adhesion to endothelial cells

    Effect of castration and age at slaughter on sensory perception of lamb meat

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    peer-reviewedThis study assessed the effect of castration and slaughter age (196–385 days old) on sensory quality of lamb meat from two sheep breeds (Scottish Blackface, SB; Texel x Scottish Blackface, TxSB). Results obtained using a trained sensory panel showed small but statistically significant differences due to castration, with rams having higher scores for Intensity of Lamb Aroma, Animal Smell/Farm Smell, Woolly Aroma, Rancid Aroma, Manure/Faecal Aroma, Sweaty Aroma and Off-flavours. SB lamb had higher scores for Intensity of Lamb Aroma, Lamb Flavour, Lamb Aftertaste, Tenderness and Juiciness. Age effects on sensory attributes were not linear and significant age × gender interactions were observed. The number of samples considered “extreme” in undesirable flavour attributes was higher among rams and T × SB animals. The impact of the sensory differences on consumer acceptability of lamb remains to be established

    Expanded CAG/CTG repeats in bipolar disorder: no correlation with phenotypic measures of illness severity

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    The hypothesis that expanded trinucleotide repeats (TNRs) contribute to the pathogenesis of bipolar disorder has received strong support from recent studies showing that, on average, bipolar patients carry larger repeat sequences of the TNR motif CAG/CTG than do controls. It has been postulated that intergenerational expansion of a TNR may be responsible for the tendency for age of onset to become earlier in younger generations (anticipation) observed in some bipolar pedigrees, and that length polymorphism may account for variability in clinical phenotype. We have used the method of repeat expansion detection to examine these predictions in a sample of 133 Caucasian DSM-III-R bipolar I probands from the British Isles. We found no evidence to support the notion that CAG/CTG TNR genes are major determinants of phenotypic severity or age at onset in the population examined, and conclude that for most cases of bipolar disorder TNR genes may operate as susceptibility genes rather than as single genes of major effect
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