Effects of Elevated H\u3csup\u3e+\u3c/sup\u3e And P\u3csub\u3ei\u3c/sub\u3e on The Contractile Mechanics of Skeletal Muscle Fibres From Young and Old Men: Implications for Muscle Fatigue in Humans

The present study aimed to identify the mechanisms responsible for the loss in muscle power and increased fatigability with ageing by integrating measures of whole‐muscle function with single fibre contractile mechanics. After adjusting for the 22% smaller muscle mass in old (73–89 years, n = 6) compared to young men (20–29 years, n = 6), isometric torque and power output of the knee extensors were, respectively, 38% and 53% lower with age. Fatigability was ∼2.7‐fold greater with age and strongly associated with reductions in the electrically‐evoked contractile properties. To test whether cross‐bridge mechanisms could explain age‐related decrements in knee extensor function, we exposed myofibres (n = 254) from the vastus lateralis to conditions mimicking quiescent muscle and fatiguing levels of acidosis (H+) (pH 6.2) and inorganic phosphate (Pi) (30 mm). The fatigue‐mimicking condition caused marked reductions in force, shortening velocity and power and inhibited the low‐ to high‐force state of the cross‐bridge cycle, confirming findings from non‐human studies that these ions act synergistically to impair cross‐bridge function. Other than severe age‐related atrophy of fast fibres (−55%), contractile function and the depressive effects of the fatigue‐mimicking condition did not differ in fibres from young and old men. The selective loss of fast myosin heavy chain II muscle was strongly associated with the age‐related decrease in isometric torque (r = 0.785) and power (r = 0.861). These data suggest that the age‐related loss in muscle strength and power are primarily determined by the atrophy of fast fibres, but the age‐related increased fatigability cannot be explained by an increased sensitivity of the cross‐bridge to H+ and Pi

Solar flares and their associated processes

The evolution of the solar neutrino flux which is described by the wave function $\Psi^T=(\nu_{eL},\nu_{XL}, \overline{\nu}_{eL}, \overline{\nu}_{XL})$ is examined. Our treatment of the problem holds for any standard model (SM) extensions possessing nonzero dipole magnetic and anapole moments. When the solar neutrino flux moves through the solar flare (SF) region in the preflare period, then it undergoes the additional (compared with the SM) resonance conversions. As a result, the weakening the electron neutrinos flux takes place. On the other hand, existence of the additional resonances lead to appearance of the $\overline{\nu}_{eL}$ and $\overline{\nu}_{XL}$ neutrinos that could be detected by the terrestrial detectors. The hypothesis of the $\nu_e$-induced $\beta$-decays is also discussed. According to it, before the large SF, decreasing the $\beta$-decay rate for some elements takes place. The possible influence of the electron antineutrino flux produced in the superflares on the regime of the hypothetical georeactor is considered.Comment: 11 pages. arXiv admin note: text overlap with arXiv:hep-ph/0401221 by other author

Use of a Systematic Consultation Process to Facilitate Nursing Research Projects: An Exemplar

PURPOSE/OBJECTIVES: The purpose of this article is to describe the use of a well-established, 5-stage consultation process, to advise a research team on planning strategies to engage domestic violence shelters (DVSs) as community partners in their study. The research team is testing a health promotion intervention for teens living in shelters with their parent and needed to enlist shelters as sites to recruit teens and conduct the intervention. Consultation aims were to (a) identify highly promising strategies described in peer-reviewed literature for identifying, recruiting, and collaborating with community organizations in research and (b) identify DVSs that would potentially serve as effective community partners for the study. METHODS: A clinical nurse specialist and a public health master's degree student led the consultation. The consultation process included (a) a systematic review of 29 peer-reviewed articles about research or program evaluation studies that engaged community partners and (b) a comprehensive online search of information about DVSs. OUTCOMES: Consultants identified 104 strategies used in studies to engage community partners and 10 specific DVSs most likely to effectively engage in the study. CONCLUSION: Clinical nurse specialists are well situated to provide consultation to research teams and should follow well-established consultation processes and systematic data collection procedures

Molecular characterization, tissue expression and sequence variability of the barramundi (Lates calcarifer) myostatin gene

Background: Myostatin (MSTN) is a member of the transforming growth factor-β superfamily that negatively regulates growth of skeletal muscle tissue. The gene encoding for the MSTN peptide is a consolidate candidate for the enhancement of productivity in terrestrial livestock. This gene potentially represents an important target for growth improvement of cultured finfish.\ud \ud Results: Here we report molecular characterization, tissue expression and sequence variability of the barramundi (Lates calcarifer) MSTN-1 gene. The barramundi MSTN-1 was encoded by three exons 379, 371 and 381 bp in length and translated into a 376-amino acid peptide. Intron 1 and 2 were 412 and 819 bp in length and presented typical GT...AG splicing sites. The upstream region contained cis-regulatory elements such as TATA-box and E-boxes. A first assessment of sequence variability suggested that higher mutation rates are found in the 5' flanking region with several SNP's present in this species. A putative micro RNA target site has also been observed in the 3'UTR (untranslated region) and is highly conserved across teleost fish. The deduced amino acid sequence was conserved across vertebrates and exhibited characteristic conserved putative functional residues including a cleavage motif of proteolysis (RXXR), nine cysteines and two glycosilation sites. A qualitative analysis of the barramundi MSTN-1 expression pattern revealed that, in adult fish, transcripts are differentially expressed in various tissues other than skeletal muscles including gill, heart, kidney, intestine, liver, spleen, eye, gonad and brain.\ud \ud Conclusion: Our findings provide valuable insights such as sequence variation and genomic information which will aid the further investigation of the barramundi MSTN-1 gene in association with growth. The finding for the first time in finfish MSTN of a miRNA target site in the 3'UTR provides an opportunity for the identification of regulatory mutations on the expression of this gene

Detecting Low Incidents Effects: The Value of Mixed Methods Research Designs in Low-N Studies

Many important educational situations such as traumatic brain injury among preschoolers, school gun violence, preadolescent eating disorders, and adolescent suicide happen relatively infrequently. In this article, the authors explain why mixed methods research designs offer more meaningful empirical results than do qualitative or quantitative designs alone when asking research questions about low incident situations. The authors present and explain three mixed methods models applicable to low incidents situations

Interdisciplinary care clinics in chronic kidney disease

The burden of chronic kidney disease (CKD) is substantial, and is associated with high hospitalization rates, premature deaths, and considerable health care costs. These factors provide strong rationale for quality improvement initiatives in CKD care. The interdisciplinary care clinic (IDC) has emerged as one solution to improving CKD care. The IDC team may include other physicians, advanced practice providers, nurses, dietitians, pharmacists, and social workers--all working together to provide effective care to patients with chronic kidney disease. Studies suggest that IDCs may improve patient education and preparedness prior to kidney failure, both of which have been associated with improved health outcomes. Interdisciplinary care may also delay the progression to end-stage renal disease and reduce mortality. While most studies suggest that IDC services are likely cost-effective, financing IDCs is challenging and many insurance providers do not pay for all of the services. There are also no robust long-term studies demonstrating the cost-effectiveness of IDCs. This review discusses IDC models and its potential impact on CKD care as well as some of the challenges that may be associated with implementing these clinics

The ventral epithelium of Trichoplax adhaerens deploys in distinct patterns cells that secrete digestive enzymes, mucus or diverse neuropeptides

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Mayorova, T. D., Hammar, K., Winters, C. A., Reese, T. S., & Smith, C. L. The ventral epithelium of Trichoplax adhaerens deploys in distinct patterns cells that secrete digestive enzymes, mucus or diverse neuropeptides. Biology Open, 8, (2019): bio045674, doi:10.1242/bio.045674.The disk-shaped millimeter-sized marine animal, Trichoplax adhaerens, is notable because of its small number of cell types and primitive mode of feeding. It glides on substrates propelled by beating cilia on its lower surface and periodically pauses to feed on underlying microorganisms, which it digests externally. Here, a combination of advanced electron and light microscopic techniques are used to take a closer look at its secretory cell types and their roles in locomotion and feeding. We identify digestive enzymes in lipophils, a cell type implicated in external digestion and distributed uniformly throughout the ventral epithelium except for a narrow zone near its edge. We find three morphologically distinct types of gland cell. The most prevalent contains and secretes mucus, which is shown to be involved in adhesion and gliding. Half of the mucocytes are arrayed in a tight row around the edge of the ventral epithelium while the rest are scattered further inside, in the region containing lipophils. The secretory granules in mucocytes at the edge label with an antibody against a neuropeptide that was reported to arrest ciliary beating during feeding. A second type of gland cell is arrayed in a narrow row just inside the row of mucocytes while a third is located more centrally. Our maps of the positions of the structurally distinct secretory cell types provide a foundation for further characterization of the multiple peptidergic cell types in Trichoplax and the microscopic techniques we introduce provide tools for carrying out these studies.The work was supported by the Intramural Research Program of the National Institute of Neurological Disorders and Stroke and the National Institutes of Health

A proper understanding of Millikan

Ruth Millikan’s teleological theory of mental content is complex and often misunderstood. This paper motivates and clarifies some of the complexities of the theory, and shows that paying careful attention to its details yields answers to a number of common objections to teleological theories, in particular, the problem of novel mental states, the problem of functionally false beliefs, and problems about indeterminacy or multiplicity of function