273 research outputs found

    Apoptotic changes in the myocardium in the course of experimentally-induced pleurisy

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    The secreted proinflammatory interleukins IL-1, IL-6 and TNF in the course of experimentally-induced pleurisy can be the cause of pathological changes in the ultrastructure of cardiac muscle and of apoptosis. The pleurisy was induced in rats by means of carrageenin. The scraps of cardiac muscle obtained during the inflammatory reaction in the pleura were analysed by means of an electron microscope. The scraps were also stained with the TUNEL method in order to find the apoptotic foci. It was proved by the experiment that the inflammatory process affected mitochondria in the cardiomyocytes, enhanced collagen fibre synthesis and contributed to the formation of apoptotic foci in the cardiac muscle

    Diffusion of Innovations and the Theory of Planned Behavior in Information Systems Research: A Metaanalysis

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    Diffusion of Innovations and the Theory of Planned Behavior provide the foundation on which a preponderance of information systems (IS) theory and research is built. IS scholars often assume that the basic factors proffered by these theories are significant determinants of innovation adoption. However, there has yet to be a meta-analytic examination of research in the IS field to validate this assumption. Herein, we use Tornatzky and Kleinā€™s seminal 1982 meta-analysis of innovation characteristics as the starting point for our meta-analytic examination of Diffusion of Innovations and Theory of Planned Behavior models in IS research. In order to focus our investigation on a common criterion variable, adoption propensity, we use antecedents from both models to develop a model of innovation adoption-behavior (IAB). After describing the relationships encompassed by the IAB model, we step through a bare-bones meta-analysis. Considering the data reported in fifty-eight empirical articles, we calculate the estimated true correlations with the criterion variable to be .53 for attitude toward behavior, .33 for subjective norm, .41 for perceived behavioral control, .42 for relative advantage, .43 for compatibility, -.28 for complexity, .32 for trialability, and .38 for observability. With the exception of complexity, all correlations generalize across studies

    Linear Superiorization for Infeasible Linear Programming

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    Linear superiorization (abbreviated: LinSup) considers linear programming (LP) problems wherein the constraints as well as the objective function are linear. It allows to steer the iterates of a feasibility-seeking iterative process toward feasible points that have lower (not necessarily minimal) values of the objective function than points that would have been reached by the same feasiblity-seeking iterative process without superiorization. Using a feasibility-seeking iterative process that converges even if the linear feasible set is empty, LinSup generates an iterative sequence that converges to a point that minimizes a proximity function which measures the linear constraints violation. In addition, due to LinSup's repeated objective function reduction steps such a point will most probably have a reduced objective function value. We present an exploratory experimental result that illustrates the behavior of LinSup on an infeasible LP problem.Comment: arXiv admin note: substantial text overlap with arXiv:1612.0653

    A 4-week, lifestyle-integrated, home-based exercise training programme elicits improvements in physical function and lean mass in older men and women: a pilot study

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    Background: Developing alternative exercise programmes that can alleviate certain barriers to exercise such as psychological, environmental or socio-economical barriers, but provide similar physiological benefits e.g. increases in muscle mass and strength, is of grave importance. This pilot study aimed to assess the efficacy of an unsupervised, 4-week, whole-body home-based exercise training (HBET) programme, incorporated into daily living activities, on skeletal muscle mass, power and strength. Methods: Twelve healthy older volunteers (63Ā±3 years, 7 men: 5 women, BMI: 29Ā±1 kg/mĀ²) carried out the 4-week ā€œlifestyle-integratedā€ HBET of 8 exercises, 3x12 repetitions each, every day. Before and after HBET, a number of physical function tests were carried out: unilateral leg extension 1-RM (one- repetition maximum), MVC (maximal voluntary contraction) leg extension, lower leg muscle power (via Nottingham Power Rig), handgrip strength and SPPBT (short physical performance battery test). A D3-Creatine method was used for assessment of whole-body skeletal muscle mass, and ultrasound was used to measure the quadriceps cross-sectional area (CSA) and vastus lateralis muscle thickness. Results: Four weeks HBET elicited significant (p<0.05) improvements in leg muscle power (276.7Ā±38.5 vs. 323.4Ā±43.4 W), maximal voluntary contraction (60Ā°: 154.2Ā±18.4 vs. 168.8Ā±15.2 Nm, 90Ā°: 152.1Ā±10.5 vs. 159.1Ā±11.4 Nm) and quadriceps CSA (57.5Ā±5.4 vs. 59.0Ā±5.3 cm2), with a trend for an increase in leg strength (1-RM: 45.7Ā±5.9 vs. 49.6Ā±6.0 kg, P=0.08). This was despite there being no significant differences in whole-body skeletal muscle mass, as assessed via D3-Creatine. Conclusions: This study demonstrates that increases in multiple aspects of muscle function can be achieved in older adults with just 4-weeks of ā€œlifestyle-integratedā€ HBET, with a cost-effective means. This training mode may prove to be a beneficial alternative for maintaining and/or improving muscle mass and function in older adults

    Nutritional Risk Factors for Tuberculosis Among Adults in the United States, 1971ā€“1992

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    The risk of developing tuberculosis (TB) may be related to nutritional status. To determine the impact of nutritional status on TB incidence, the authors analyzed data from the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study (NHEFS). NHANES I collected information on a probability sample of the US population in 1971ā€“1975. Adults were followed up in 1982ā€“1992. Incident TB cases were ascertained through interviews, medical records, and death certificates. TB incidences were compared across different levels of nutritional status after controlling for potential confounding using proportional hazards regression appropriate to the complex sample design. TB incidence among adults with normal body mass index was 24.7 per 100,000 person-years (95% confidence interval (CI): 13.0, 36.3). In contrast, among persons who were underweight, overweight, and obese, estimated TB incidence rates were 260.2 (95% CI: 98.6, 421.8), 8.9 (95% CI: 2.2, 15.6), and 5.1 (95% CI: 0.0, 10.5) per 100,000 person-years, respectively. Adjusted hazard ratios were 12.43 (95% CI: 5.75, 26.95), 0.28 (95% CI: 0.13, 0.63), and 0.20 (95% CI: 0.07, 0.62), respectively, after controlling for demographic, socioeconomic, and medical characteristics. A low serum albumin level also increased the risk of TB, but low vitamin A, thiamine, riboflavin, and iron status did not. A populationā€™s nutritional profile is an important determinant of its TB incidence

    Challenges of tuberculosis management in high and low prevalence countries in a mobile world

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    This article is made available via the PMC Open Access Subset for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.In this issue of the PCRJ, Bishara et al. 1 present a case report about the treatment of a pregnant woman with tuberculosis (TB). She had emigrated from a country with a high prevalence of TB to one with a lower prevalence. This presented a challenge to her physicians who were faced with identifying and treating close contacts who were also infected. This Perspective article explores in more depth some of the questions raised by this case report. It discusses the role of primary care physicians in low prevalence countries who can implement evidence-based screening programmes, it discusses effective strategies for the diagnosis and treatment of TB in countries with high TB prevalence, and it presents insights from medical anthropology that can help practitioners overcome the barriers to TB diagnosis, treatment and screening described in the case report

    Cryptosporidium, Enterocytozoon, and Cyclospora Infections in Pediatric and Adult Patients with Diarrhea in Tanzania.

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    Cryptosporidiosis, microsporidiosis, and cyclosporiasis were studied in four groups of Tanzanian inpatients: adults with AIDS-associated diarrhea, children with chronic diarrhea (of whom 23 of 59 were positive [+] for human immunodeficiency virus [HIV]), children with acute diarrhea (of whom 15 of 55 were HIV+), and HIV control children without diarrhea. Cryptosporidium was identified in specimens from 6/86 adults, 5/59 children with chronic diarrhea (3/5, HIV+), 7/55 children with acute diarrhea (0/7, HIV+), and 0/20 control children. Among children with acute diarrhea, 7/7 with cryptosporidiosis were malnourished, compared with 10/48 without cryptosporidiosis (P < .01). Enterocytozoon was identified in specimens from 3/86 adults, 2/59 children with chronic diarrhea (1 HIV+), 0/55 children with acute diarrhea, and 4/20 control children. All four controls were underweight (P < .01). Cyclospora was identified in specimens from one adult and one child with acute diarrhea (HIV-). Thus, Cryptosporidium was the most frequent and Cyclospora the least frequent pathogen identified. Cryptosporidium and Enterocytozoon were associated with malnutrition. Asymptomatic fecal shedding of Enterocytozoon in otherwise healthy, HIV children has not been described previously

    Whey Protein Augments Leucinemia and Post-Exercise p70S6K1 Activity Compared to a Hydrolysed Collagen Blend When in Recovery From Training With Low Carbohydrate Availability

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    We examined the effects of whey versus collagen protein on skeletal muscle cell signalling responses associated with mitochondrial biogenesis and protein synthesis in recovery from an acute training session completed with low carbohydrate (CHO) availability. In a repeated measures design (after adhering to a 36-h exercise-dietary intervention to standardise pre-exercise muscle glycogen), eight males completed a 75-min non-exhaustive cycling protocol and consumed 22 g of a hydrolysed collagen blend (COLLAGEN) or whey (WHEY) protein 45 min prior to exercise, 22 g during exercise and 22 g immediately post-exercise. Exercise decreased (P0.05) was observed for p53, Parkin and Beclin1 mRNA. Exercise suppressed (P<0.05) p70S6K1 activity in both conditions immediately post-exercise (ā‰ˆ 25 fmol.min-1.mg-1). Post-exercise feeding increased p70S6K1 activity at 1.5 h post-exercise (P<0.05), the magnitude of which was greater (P <0.05) in WHEY (180 Ā± 105 fmol.min-1.mg-1) versus COLLAGEN (73 Ā± 42 fmol.min-1.mg-1). We conclude that protein composition does not modulate markers of mitochondrial biogenesis when in recovery from a training session deliberately completed with low CHO availability. In contrast, whey protein augments post-exercise p70S6K activity compared with hydrolysed collagen, as likely mediated via increased leucine availability

    Convergence and Perturbation Resilience of Dynamic String-Averaging Projection Methods

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    We consider the convex feasibility problem (CFP) in Hilbert space and concentrate on the study of string-averaging projection (SAP) methods for the CFP, analyzing their convergence and their perturbation resilience. In the past, SAP methods were formulated with a single predetermined set of strings and a single predetermined set of weights. Here we extend the scope of the family of SAP methods to allow iteration-index-dependent variable strings and weights and term such methods dynamic string-averaging projection (DSAP) methods. The bounded perturbation resilience of DSAP methods is relevant and important for their possible use in the framework of the recently developed superiorization heuristic methodology for constrained minimization problems.Comment: Computational Optimization and Applications, accepted for publicatio
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