560 research outputs found

    Laboratory study of the impact of repetitive electrical and mechanical stimulation on brown shrimp Crangon crangon

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    Pulse trawling is currently the best available alternative to beam trawling in the brown shrimp Crangon crangon and Sole Solea solea (also known as Solea vulgaris) fisheries. To evaluate the effect of repetitive exposure to electrical fields, brown shrimp were exposed to the commercial electrodes and pulse settings used to catch brown shrimp (shrimp startle pulse) or Sole (Sole cramp pulse) 20 times in 4 d and monitored for up to 14 d after the first exposure. Survival, egg loss, molting, and the degree of intranuclear bacilliform virus (IBV) infection were evaluated and compared with those in stressed but not electrically exposed (procedural control) and nonstressed, nonexposed (control) brown shrimp as well as brown shrimp exposed to mechanical stimuli. The lowest survival at 14 d (57.3%) occurred in the Sole cramp pulse treatment, and this was significantly lower than in the group with the highest survival, the procedural control (70.3%). No effect of electrical stimulation on the severity of IBV infection was found. The lowest percentage of molts occurred in the repetitive mechanical stimulation treatment (14.0%), and this was significantly lower than in the group with the highest percentage of molts, the procedural control (21.7%). Additionally, the mechanically stimulated brown shrimp that died during the experiment had a significantly larger size than the surviving individuals. Finally, no effect of the shrimp startle pulse was found. Therefore, it can be concluded that repetitive exposure to a cramp stimulus and mechanical stimulation may have negative effects on the growth and/or survival of brown shrimp. However, there is no evidence that electrical stimulation during electrotrawls would have a larger negative impact on brown shrimp stocks than mechanical stimulation during conventional beam trawling

    How needs and preferences of employees influence participation in health promotion programs: A six-month follow-up study

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    Background: Low participation in health promotion programs (HPPs) might hamper their effectiveness. A potential reason for low participation is disagreement between needs and preferences of potential participants and the actual HPPs offered. This study aimed to investigate employees' need and preferences for HPPs, whether these are matched by what their employers provide, and whether a higher agreement enhanced participation. Methods: Employees of two organizations participated in a six-month follow-up study (n = 738). At baseline, information was collected on employees' needs and preferences for the topic of the HPP (i.e. physical activity, healthy nutrition, smoking cessation, stress management, general health), whether they favored a HPP via their employer or at their own discretion, and their preferred HPP regarding three components with each two alternatives: mode of delivery (individual vs. group), intensity (single vs. multiple meetings), and content (assignments vs. information). Participation in HPPs was assessed at six-month

    Barriers and facilitators for participation in health promotion programs among employees: A six-month follow-up study

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    Background: Health promotion programs (HPPs) are thought to improve health behavior and health, and their effectiveness is increasingly being studied. However, participation in HPPs is usually modest and effect sizes are often small. This study aims to (1) gain insight into the degree of participation of employees in HPPs, and (2) identify factors among employees that are associated with both their intention to participate and actual participation in HPPs. Methods. Employees of two organizations were invited to participate in a six-month follow-up study (n = 744). Using questionnaires, information on participation in HPPs was collected in two categories: employees' intention at baseline to participate and their actual participation in a HPP during the follow-up period. The following potential determinants were assessed at baseline: social-cognitive factors, perceived barriers and facilitators, beliefs about health at work, health behaviors, and self-perceived health. Logistic regression analyses, adjusted for demographics and organization, were used to examine associations between potential determinants and intention to participate, and to examine the effect of these determinants on actual participation during follow-up. Results: At baseline, 195 employees (26%) expressed a positive intention towards participation in a HPP. During six months of follow-up, 83 employees (11%) actually participated. Participants positively inclined at baseline to participate in a HPP were more likely to actually participate (OR = 3.02, 95% CI: 1.88-4.83). Privacy-related barriers, facilit

    Modelling Technical and Biological Effects in scRNA-seq data with Scalable GPLVMs

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    Single-cell RNA-seq datasets are growing in size and complexity, enabling the study of cellular composition changes in various biological/clinical contexts. Scalable dimensionality reduction techniques are in need to disentangle biological variation in them, while accounting for technical and biological confounders. In this work, we extend a popular approach for probabilistic non-linear dimensionality reduction, the Gaussian process latent variable model, to scale to massive single-cell datasets while explicitly accounting for technical and biological confounders. The key idea is to use an augmented kernel which preserves the factorisability of the lower bound allowing for fast stochastic variational inference. We demonstrate its ability to reconstruct latent signatures of innate immunity recovered in Kumasaka et al. (2021) with 9x lower training time. We further analyze a COVID dataset and demonstrate across a cohort of 130 individuals, that this framework enables data integration while capturing interpretable signatures of infection. Specifically, we explore COVID severity as a latent dimension to refine patient stratification and capture disease-specific gene expression.Comment: Machine Learning and Computational Biology Symposium (Oral), 202

    Demographic, behavioral, and psychosocial correlates of using the website component of a worksite physical activity and healthy nutrition promotion program: a longitudinal study.

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    BACKGROUND: Internet-delivered behavior change programs have the potential to reach a large population. However, low participation levels and high levels of attrition are often observed. The worksite could be a setting suitable for reaching and retaining large numbers of people, but little is known about reach and use of Internet-delivered health promotion programs in the worksite setting. OBJECTIVE: This study aimed (1) to gain more insight in the use of the website component of a worksite behavior change intervention and (2) to identify demographic, behavioral, and psychosocial factors associated with website use. METHODS: The study was an observational study among participants from 5 workplaces in a cluster randomized controlled trial. At baseline, all participants visited a study website to fill out the baseline questionnaire. Then a physical health check was done followed by face-to-face advice. After this contact, all participants received an email to promote visiting the website to view their health check results and the personal advice based on the baseline questionnaire. In the subsequent period, only participants in the intervention group received monthly email messages to promote website visits and were offered additional Web-based tools (self-monitors and a food frequency questionnaire [FFQ] assessing saturated fat intake) to support their behavior change. Website use was monitored by website statistics registering website access. Complete data were available for 726 employees. Logistic regression analyses were conducted to identify characteristics of employees who visited and used the website. RESULTS: In total, 43% of the participants visited the website after the email to promote website visits. Participants who were insufficiently physically active were less likely to visit the website (odds ratio [OR] 0.63, 95% confidence interval [CI] 0.45-0.88), whereas individuals with an elevated total cholesterol level visited the website more often (OR 1.44, 95% CI 1.05-1.98). The monthly emails in the intervention group resulted in higher website use during a 3-month period (18% versus 5% in the reference group, OR 3.96, 95% CI 2.30-6.82). Participants with a positive attitude toward increasing physical activity were less likely to visit the website (OR 0.54, 95% CI 0.31-0.93) or to use the self-monitor and FFQ (OR 0.50, 95% CI 0.25-0.99). Female workers visited the website more often to monitor their behavior and to receive advice on fat intake (OR 2.36, 95% CI 1.14-4.90). CONCLUSIONS: Almost half of the participants used the website component of a worksite behavior change program. M

    Carnitine Acetyltransferase Mitigates Metabolic Inertia and Muscle Fatigue during Exercise

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    SummaryAcylcarnitine metabolites have gained attention as biomarkers of nutrient stress, but their physiological relevance and metabolic purpose remain poorly understood. Short-chain carnitine conjugates, including acetylcarnitine, derive from their corresponding acyl-CoA precursors via the action of carnitine acetyltransferase (CrAT), a bidirectional mitochondrial matrix enzyme. We show here that contractile activity reverses acetylcarnitine flux in muscle, from net production and efflux at rest to net uptake and consumption during exercise. Disruption of this switch in mice with muscle-specific CrAT deficiency resulted in acetyl-CoA deficit, perturbed energy charge, and diminished exercise tolerance, whereas acetylcarnitine supplementation produced opposite outcomes in a CrAT-dependent manner. Likewise, in exercise-trained compared to untrained humans, post-exercise phosphocreatine recovery rates were positively associated with CrAT activity and coincided with dramatic shifts in muscle acetylcarnitine dynamics. These findings show acetylcarnitine serves as a critical acetyl buffer for working muscles and provide insight into potential therapeutic strategies for combatting exercise intolerance
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