43 research outputs found

    The Impact of a \u3ci\u3ePGYM\u3c/i\u3e Variant on Myophosphorylase Deficiency in Red Angus Composite Cattle and Changes in the Skeletal Muscle Transcriptome Due to the Intramuscular Administration of Lidocaine in Wether Lambs

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    Project 1 focused on eight calves in a Nebraska herd (composite Simmental, Red Angus, Gelbvieh) that displayed exercise intolerance during forced activity. Available sire pedigrees contained a paternal ancestor within 2-4 generations in all affected calves. Pedigrees of the calves’ dams were unavailable, however, the cows were ranch-raised and retained from prior breeding seasons, where bulls used for breeding occasionally had a common ancestor. Therefore, it was hypothesized that a de novo autosomal recessive variant was causative of exercise intolerance in these calves. A genome-wide association analysis followed by whole-genome sequencing led to the identification of a variant in the gene PYGM (BTA29:g.42989581G\u3eA). The variant, confirmed to be present in the skeletal muscle transcriptome, was predicted to produce a premature stop codon (p.Arg650*). The protein product of PYGM, myophosphorylase, breaks down glycogen in skeletal muscle. Myophosphorylase deficiency poses welfare concerns for affected animals and negatively impacts the final product. Project 2 examined the impact of lidocaine usage on muscle used to study the transcriptome. Lidocaine acts by blocking sodium channels necessary for sensory neurons to relay pain signals to the brain. In animal research, lidocaine is used to ensure animal comfort during tissue biopsy. Biopsied samples may then be used to study the transcriptome, assuming that lidocaine-treated tissue reflects genomic activity of untreated tissue. The objective of this study was to determine the effect of intramuscular lidocaine injection on skeletal muscle gene expression in sheep. RNA sequencing analysis was performed on muscle samples collected from lidocaine-treated and untreated limbs. Lidocaine administration led to differential expression of genes associated with immune response modulation, inflammatory suppression, and muscular function. Despite variations in gene expression profiles between validation samples, commonalities were observed in pathways related to inflammation and muscular function, emphasizing the need for cautious interpretation of transcriptomic data in the presence of pharmacological interventions like lidocaine. Advisor: Jessica L. Peterse

    An autosomal recessive variant in \u3ci\u3ePYGM\u3c/i\u3e causes myophosphorylase deficiency in Red Angus composite cattle

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    Background Between 2020 and 2022, eight calves in a Nebraska herd (composite Simmental, Red Angus, Gelbvieh) displayed exercise intolerance during forced activity. In some cases, the calves collapsed and did not recover. Available sire pedigrees contained a paternal ancestor within 2–4 generations in all affected calves. Pedigrees of the calves’ dams were unavailable, however, the cows were ranch-raised and retained from prior breeding seasons, where bulls used for breeding occasionally had a common ancestor. Therefore, it was hypothesized that a de novo autosomal recessive variant was causative of exercise intolerance in these calves. Results A genome-wide association analysis utilizing SNP data from 6 affected calves and 715 herd mates, followed by whole-genome sequencing of 2 affected calves led to the identification of a variant in the gene PYGM (BTA29:g.42989581G \u3e A). The variant, confirmed to be present in the skeletal muscle transcriptome, was predicted to produce a premature stop codon (p.Arg650*). The protein product of PYGM, myophosphorylase, breaks down glycogen in skeletal muscle. Glycogen concentrations were fluorometrically assayed as glucose residues demonstrating significantly elevated glycogen concentrations in affected calves compared to cattle carrying the variant and to wildtype controls. The absence of the PYGM protein product in skeletal muscle was confirmed by immunohistochemistry and label-free quantitative proteomics analysis; muscle degeneration was confirmed in biopsy and necropsy samples. Elevated skeletal muscle glycogen persisted after harvest, resulting in a high pH and dark-cutting beef, which is negatively perceived by consumers and results in an economic loss to the industry. Carriers of the variant did not exhibit differences in meat quality or any measures of animal well-being. Conclusions Myophosphorylase deficiency poses welfare concerns for affected animals and negatively impacts the final product. The association of the recessive genotype with dark-cutting beef further demonstrates the importance of genetics to not only animal health but to the quality of their product. Although cattle heterozygous for the variant may not immediately affect the beef industry, identifying carriers will enable selection and breeding strategies to prevent the production of affected calves

    Pneumococcal carriage in sub-Saharan Africa--a systematic review.

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    BACKGROUND: Pneumococcal epidemiology varies geographically and few data are available from the African continent. We assess pneumococcal carriage from studies conducted in sub-Saharan Africa (sSA) before and after the pneumococcal conjugate vaccine (PCV) era. METHODS: A search for pneumococcal carriage studies published before 2012 was conducted to describe carriage in sSA. The review also describes pneumococcal serotypes and assesses the impact of vaccination on carriage in this region. RESULTS: Fifty-seven studies were included in this review with the majority (40.3%) from South Africa. There was considerable variability in the prevalence of carriage between studies (I-squared statistic = 99%). Carriage was higher in children and decreased with increasing age, 63.2% (95% CI: 55.6-70.8) in children less than 5 years, 42.6% (95% CI: 29.9-55.4) in children 5-15 years and 28.0% (95% CI: 19.0-37.0) in adults older than 15 years. There was no difference in the prevalence of carriage between males and females in 9/11 studies. Serotypes 19F, 6B, 6A, 14 and 23F were the five most common isolates. A meta-analysis of four randomized trials of PCV vaccination in children aged 9-24 months showed that carriage of vaccine type (VT) serotypes decreased with PCV vaccination; however, overall carriage remained the same because of a concomitant increase in non-vaccine type (NVT) serotypes. CONCLUSION: Pneumococcal carriage is generally high in the African continent, particularly in young children. The five most common serotypes in sSA are among the top seven serotypes that cause invasive pneumococcal disease in children globally. These serotypes are covered by the two PCVs recommended for routine childhood immunization by the WHO. The distribution of serotypes found in the nasopharynx is altered by PCV vaccination

    SNi from SN2: a front-face mechanism ‘synthase’ engineered from a retaining hydrolase

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    SNi or SNi-like mechanisms, in which leaving group departure and nucleophile approach occur on the same ‘front’ face, have been observed previously experimentally and computationally in both the chemical and enzymatic (glycosyltransferase) substitution reactions of α-glycosyl electrophiles. Given the availability of often energetically comparable competing pathways for substitution (SNi vs SN1 vs SN2) the precise modulation of this archetypal reaction type should be feasible. Here, we show that the drastic engineering of a protein that catalyzes substitution, a retaining β-glycosidase (from Sulfolobus solfataricus SSβG), apparently changes the mode of reaction from “SN2” to “SNi”. Destruction of the nucleophilic Glu387 of SSβG-WT through Glu387Tyr mutation (E387Y) created a catalyst (SSβG-E387Y) with lowered but clear transglycosylation substitution activity with activated substrates, altered substrate and reaction preferences and hence useful synthetic (‘synthase’) utility by virtue of its low hydrolytic activity with unactivated substrates. Strikingly, the catalyst still displayed retaining β stereoselectivity, despite lacking a suitable nucleophile; pH-activity profile, mechanism-based inactivators and mutational analyses suggest that SSβG-E387Y operates without either the use of nucleophile or general acid/base residues, consistent with a SNi or SNi-like mechanism. An x-ray structure of SSβG-E387Y and subsequent metadynamics simulation suggest recruitment of substrates aided by a π-sugar interaction with the introduced Tyr387 and reveal a QM/MM free energy landscape for the substitution reaction catalyzed by this unnatural enzyme similar to those of known natural, SNi-like glycosyltransferase (GT) enzymes. Proton flight from the putative hydroxyl nucleophile to the developing p-nitrophenoxide leaving group of the substituted molecule in the reactant complex creates a hydrogen bond that appears to crucially facilitate the mechanism, mimicking the natural mechanism of SNi-GTs. An oxocarbenium ion-pair minimum along the reaction pathway suggests a step-wise SNi-like DN*ANss rather than a concerted SNi DNAN mechanism. This first observation of a front face mechanism in a β-retaining glycosyl transfer enzyme highlights, not only that unusual SNi reaction pathways may be accessed through direct engineering of catalysts with suitable environments, but also suggests that ‘β-SNi’ reactions are also feasible for glycosyl transfer enzymes and the more widespread existence of SNi or SNi-like mechanism in nature

    Human Resource Flexibility as a Mediating Variable Between High Performance Work Systems and Performance

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    Much of the human resource management literature has demonstrated the impact of high performance work systems (HPWS) on organizational performance. A new generation of studies is emerging in this literature that recommends the inclusion of mediating variables between HPWS and organizational performance. The increasing rate of dynamism in competitive environments suggests that measures of employee adaptability should be included as a mechanism that may explain the relevance of HPWS to firm competitiveness. On a sample of 226 Spanish firms, the study’s results confirm that HPWS influences performance through its impact on the firm’s human resource (HR) flexibility

    2018 Research & Innovation Day Program

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    A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1005/thumbnail.jp

    Minimising fear and anxiety in working dogs:a review

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    The causes of fear and anxiety in working dogs are multifactorial and may include inherited characteristics that differ between individuals (e.g. Goddard and Beilharz, 1982; 1984a,b ), influences of the environment ( Lefebvre et al., 2007 ), and learned experiences during particular sensitive periods ( Appleby et al., 2002 ) and throughout life. Fear-related behavior compromises performance, leads to significant numbers of dogs failing to complete training (e.g., Murphy, 1995; Batt et al., 2008 ), early withdrawals from working roles ( Caron-Lormier et al., 2016 ), and can jeopardize dog and handler safety. Hence, amelioration of fear and anxiety is critical to maintain dogs in working roles and to ensure their well-being. Although current methods of selection and training are seemingly effective at producing many dogs which work in a remarkable array of environments, some dogs do not make the grade, and longevity of service is not always maximized. Programs should strive for optimal efficiency and they need to continually analyze the value of each component of their program, seek evidence for its value and explore potential evidence-based improvements. Here we discuss scientific evidence for methods and strategies which may be of value in reducing the risk of fear behaviors developing in the working dog population and suggest potentially valuable techniques and future research to explore the benefit of these approaches. The importance of environmental influences, learning opportunities, and effects of underlying temperament on the outward expression of fear and anxiety should not be underestimated. Identification of characteristics which predict resilience to stress are valuable, both to enable careful breeding for these traits and to develop predictive tests for puppies and procured animals. It is vitally important to rear animals in optimal environments and introduce them to a range of stimuli in a positive, controlled, and gradual way, as these can all help minimize the number of dogs which develop work-inhibiting fears. Future research should explore innovative methods to best measure the relative resilience of dogs to stressful events. This could include developing optimal exposure protocols to minimize the development of fear and anxiety, and exploring the influence of social learning and the most effective elements of stimulus presentation

    Acceptability and feasibility of a low-cost, theory-based and co-produced intervention to reduce workplace sitting time in desk-based university employees

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    BACKGROUND: Prolonged sedentary time is linked with poor health, independent of physical activity levels. Workplace sitting significantly contributes to sedentary time, but there is limited research evaluating low-cost interventions targeting reductions in workplace sitting. Current evidence supports the use of multi-modal interventions developed using participative approaches. This study aimed to explore the acceptability and feasibility of a low-cost, co-produced, multi-modal intervention to reduce workplace sitting. METHODS: The intervention was developed with eleven volunteers from a large university department in the UK using participative approaches and “brainstorming” techniques. Main components of the intervention included: emails suggesting ways to “sit less” e.g. walking and standing meetings; free reminder software to install onto computers; social media to increase awareness; workplace champions; management support; and point-of-decision prompts e.g. by lifts encouraging stair use. All staff (n = 317) were invited to take part. Seventeen participated in all aspects of the evaluation, completing pre- and post-intervention sitting logs and questionnaires. The intervention was delivered over four weeks from 7th July to 3rd August 2014. Pre- and post-intervention difference in daily workplace sitting time was presented as a mean ± standard deviation. Questionnaires were used to establish awareness of the intervention and its various elements, and to collect qualitative data regarding intervention acceptability and feasibility. RESULTS: Mean baseline sitting time of 440 min/workday was reported with a mean reduction of 26 ± 54 min/workday post-intervention (n = 17, 95 % CI = −2 to 53). All participants were aware of the intervention as a whole, although there was a range of awareness for individual elements of the intervention. The intervention was generally felt to be both acceptable and feasible. Management support was perceived to be a strength, whilst specific strategies that were encouraged, including walking and standing meetings, received mixed feedback. CONCLUSIONS: This small-scale pilot provides encouragement for the acceptability and feasibility of low-cost, multi-modal interventions to reduce workplace sitting in UK settings. Evaluation of this intervention provides useful information to support participatory approaches during intervention development and the potential for more sustainable low-cost interventions. Findings may be limited in terms of generalisability as this pilot was carried out within a health-related academic setting
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