Effects of Sheep Sires on Muscle Fiber Characteristics, Fatty Acid Composition and Volatile Flavor Compounds in F1 Crossbred Lambs.

Crossbreeding significantly improves meat production performance in sheep; however, whether hybridization changes the meat quality characteristics of lambs is uncertain. We analyzed the effects of three different hybrid sires on muscle fiber characteristics (MFCs), fatty acid composition (FAC), and volatile flavor compounds (VFCs) in lambs under identical feeding conditions. Compared with those of purebred lambs, the muscle fiber diameter and cross-sectional areas of the crossbred lambs were significantly decreased (p < 0.05), and the collagen fiber content was significantly increased (p < 0.05). The numbers and area ratios of the fast and slow muscle fibers did not significantly differ between the purebred and crossbred lambs, but the expressions of four MyHC gene types differed significantly (p < 0.05). Twenty-three fatty acids were identified in both the purebred and crossbred lambs, of which thirteen were differentially expressed (p < 0.05). Saturated fatty acid (SFA) contents in the crossbred lambs were significantly increased (p < 0.05), whereas the monounsaturated fatty acid content was significantly decreased (p < 0.05). Polyunsaturated fatty acid/SFA and n-6/n-3 ratios were significantly lower in the crossbred lambs than in the purebred lambs (p < 0.05). Twenty-five VFCs were identified among the three hybrids, and aldehydes were the main VFCs. Eleven VFCs were differentially expressed in the crossbred lambs (p < 0.05). Hybrid sires affected the MFCs, FAC, and VFCs of the F1 lambs, thus providing a reference for high-quality mutton production.

Association between work-family conflict and overall well-being among Chinese nurse leaders.

AIM: To explore the association between work-family conflict and overall well-being among Chinese nurse leaders. BACKGROUND: Nurse leaders are constantly busy at the clinical frontline, mostly experience high stress levels at work and have little time to spend with the family. There is little evidence to know about the association between work-family conflict and overall well-being, which is essential for high-quality medical care. METHODS: A cluster sampling method was used to recruit 42 nurse leaders. Data were collected using the Chinese versions of the Multidimensional Work-Family Conflict Scale and the General Well-Being Schedule. Descriptive analyses, independent t tests, ANOVAs and Pearson's correlation were used for the statistical analysis. RESULTS: The mean scores (SD) of work-family conflict and well-being were 2.17 (0.57) and 4.51 (0.61), respectively. Negative correlations were observed with strain-based and behaviour-based work-family conflict and overall well-being. CONCLUSION: Stress from work-family conflict is positively correlated with the overall well-being of Chinese nurse leaders. IMPLICATIONS FOR NURSING MANAGEMENT: Hospital administrators should be aware of specific risk factors and implement accordingly the interventional strategies to decrease the stress levels and improve the overall well-being of nurse leaders.

Label-free quantification of protein expression in the rainbow trout (Oncorhynchus mykiss) in response to short-term exposure to heat stress.

Rainbow trout (Oncorhynchus mykiss) are a cold-water salmonid species that is highly susceptible to heat stress. Summer temperature stress is a common issue in trout aquaculture. To better understand the molecular mechanisms of the heat-stress response in the trout, we used label-free quantitative proteome techniques to identify differentially expressed proteins in the livers of rainbow trout exposed to heat stress. We identified 3362 proteins and 152 differentially expressed proteins (p < 0.05; fold-change >2). Of these, 37 were uniquely expressed in the heat-stress group and 35 were uniquely expressed in the control group. In addition, 42 proteins were significantly upregulated (fold-change >2) and 38 proteins were significantly downregulated (fold-change >2). GO (Gene Ontology) analysis indicated that these differentially expressed proteins were primarily expressed in the nucleus, extracellular matrix, and cytoplasm, and were associated with a variety of functions, including protein binding/bridging and enzyme facilitation. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis of the differentially expressed proteins showed that, during high temperature stress, many biological processes were extensively altered, particularly the estrogen signaling pathway, the complement and coagulation cascades, and the platelet activation pathway. Our study focused on the identification of a systematic approach for the characterization of regulatory networks. Our results provide a framework for further studies of the heat-stress response in fish.

Effects of heat stress on respiratory burst, oxidative damage and SERPINH1 (HSP47) mRNA expression in rainbow trout Oncorhynchus mykiss.

For rainbow trout Oncorhynchus mykiss, high temperature is a major abiotic stress that limits its growth and productivity. In this study, spleen macrophage respiratory burst (RB), serum superoxide dismutase (SOD), serum malondialdehyde (MDA) and mRNA expression of the SERPINH1 (HSP47) gene in different tissues (liver, spleen, head kidney and heart) were measured in unstressed (18 °C) and heat-stressed (25 °C) fish. Spleen macrophage RB activity, serum SOD activity and MDA content all increased significantly (P < 0.05) during heat shock, and peaked at 8, 12 and 4 h, respectively. SERPINH1 mRNA expression responded in a time- and tissue-specific manner to heat stress, which was mainly reflected in the significant up-regulation in all tissues (P < 0.05) and greater expression in the liver than the other tissues (P < 0.05). During the heat-shock recovery period, the MDA content returned to the unstressed level. These results indicate that heat shock causes cell injury, induces oxidative damage and promotes SERPINH1 mRNA expression, which plays an important protective function during heat stress in O. mykiss. In practice, close attention should be given to temperature changes in O. mykiss production to reduce the effects of high temperature.