134 research outputs found
Experimental and theoretical study of vibrations of a cantilevered beam using a ZnO piezoelectric sensor
Piezoelectric sensors can measure vibrations of solid structures very accurately. A model of a cantilevered beam, with a ZnO film on one side is presented. Both viscous and internal damping are considered. The output of the sensor is modeled and matched with experimental results by adjusting the damping parameters. A theoretical formulation for damage is introduced. Experimental results for a damaged beam confirm the shift in frequencies to lower values. The model is used to identify the extent of the damage
Experimental and theoretical study of vibrations of a cantilevered beam using a ZnO piezoelectric sensor
Supplement 1) Peer-reviewed paper
Abstract This study was conducted to investigate the effect of dietary fatty acids (FA) on the fertility and hatchability of laying hens at the end-of-lay period (69 -77 weeks of age). Five isoenergetic (12.4 MJ ME/kg DM) and isonitrogenous (170 g CP/kg DM) diets were formulated using different lipid sources (30 g/kg inclusion) to manipulate the dietary FA profile. The control diet was formulated using a 50 : 50 blend of linseed and fish oil, while fish oil was used in the polyunsaturated n-3 treatment. Sunflower oil was used in the polyunsaturated n-6 treatment, while in the mono-unsaturated n-9 diet high oleic acid (HO) sunflower oil was used. Lastly, tallow was used as a lipid source in the saturated FA diet. One hundred and twenty five hens (n = 25/treatment) and 50 cockerels (n = 10/treatment) of the Hy-Line Silver-Brown genotype were randomly allocated to the five dietary treatments at 20 weeks of age. From 69 weeks of age, hens were inseminated with 0.06 mL undiluted semen from cockerels within the same dietary treatment. Between 71 and 78 weeks of age (49 days) a total of 588 eggs-per-treatment were collected, individually marked (date and hen number) and incubated in a single-stage still-air incubator. Eggs were candled on D7 and D14 to determine embryonic mortalities and a 24 h window for hatching was allowed (D21 + 24 h). Although the fish oil treatment resulted in the lowest egg weights (59.3 g) and fertility (84.6%), it recorded the highest hatchability (76%). In contrast, the sunflower oil treatment recorded the lowest hatchability (58.2%) of all treatments, despite its high egg fertility (89.6%). Results of the study suggest that the dietary fatty acid content, in particular the n-3 and n-6 levels, need critical consideration in terms of concentration and ratio in the formulation of breeder diets to limit embryonic mortalities during incubation
Categorizing and Defining Popular Psychological Terms Used Within the Youth Athlete Talent Development Literature: A Systematic Review
Inconsistencies in the use and definition of psychological terms within the talent development literature have been identified. To advance the scientific field, the creation of a shared language is recommended. This review aimed to systematically (i) identify terms used in empirical studies to describe psychological components purported to facilitate athletes' development; (ii) analyse definition and meanings of these terms; and (iii) group, label and define terms into meaning clusters. A systematic review using a narrative approach to synthesise information was conducted. A comprehensive literature search of SPORTDiscus, PsycINFO, PsycARTICLES, and ERIC was completed in May 2015. In total 21 empirical studies, published between 2002 and 2015, met the inclusion criteria and were included in the narrative synthesis. Thematic analysis was used to analyse the findings. Identified psychological terms were categorised as psychological skills or psychological characteristics. Psychological skills were defined as athletesâ ability to use learned psychological strategies (e.g., self-talk) to regulate and facilitate the enhancement of psychological characteristics. Psychological characteristics were defined as predispositions that impact upon athlete development (e.g., self-confidence). Despite being relatively enduring and consistent across a range of situations, psychological characteristics can be regulated and enhanced through the use of psychological skills
Extrovert Followership and its Impact on Agreeable Leadership
This study recons the need for research on effective role of followership in mentoring a leader to set pattern or direction for leader. A reinvented concept of leader being a team man needs active participation from followers in changing business dynamics. The sample consisting of middle level management having leader (heads/ supervisors from education sector) above it has been taken and results are achieved using inferential statistics, so to verify the need of followers for result oriented leadership. The results depict that certain personality traits backed by âBig Five Modelâ are found to be important for followers to have an impact on leaderâs decision making. As this study analyses the mutual characteristic of leader follower relation statistically while putting follower on the fore front, the originality of study is ensured. As for limitation, this study may show different results as per variant geographical and economical regions in which followersâ expectations may vary accordingly
Determinants of excellent/good self-rated health among HIV positive individuals in South Africa: evidence from a 2012 nationally representative household survey
High-frequency, functional HIV-specific T-follicular helper and regulatory cells are present within germinal centers in children but not adults
Broadly neutralizing antibodies (bnAbs) against HIV-1 are an effective means of preventing transmission. To better understand the mechanisms by which HIV-specific bnAbs naturally develop, we investigated blood and lymphoid tissue in pediatric infection, since potent bnAbs develop with greater frequency in children than adults. As in adults, the frequency of circulating effector T-follicular helper cells (TFH) in HIV infected, treatment naĂŻve children correlates with neutralization breadth. However, major differences between children and adults were also observed both in circulation, and in a small number of tonsil samples. In children, TFH cells are significantly more abundant, both in blood and in lymphoid tissue germinal centers, than in adults. Second, HIV-specific TFH cells are more frequent in pediatric than in adult lymphoid tissue and secrete the signature cytokine IL-21, which HIV-infected adults do not. Third, the enrichment of IL-21-secreting HIV-specific TFH in pediatric lymphoid tissue is accompanied by increased TFH regulation via more abundant regulatory follicular T-cells and HIV-specific CXCR5+ CD8 T-cells compared to adults. The relationship between regulation and neutralization breadth is also observed in the pediatric PBMC samples and correlates with neutralization breadth. Matching neutralization data from lymphoid tissue samples is not available. However, the distinction between infected children and adults in the magnitude, quality and regulation of HIV-specific TFH responses is consistent with the superior ability of children to develop high-frequency, potent bnAbs. These findings suggest the possibility that the optimal timing for next generation vaccine strategies designed to induce high-frequency, potent bnAbs to prevent HIV infection in adults would be in childhood
The efficacy and safety of prokinetic agents in critically ill patients receiving enteral nutrition: a systematic review and meta-analysis of randomized trials.
BACKGROUND: Intolerance to enteral nutrition is common in critically ill adults, and may result in significant morbidity including ileus, abdominal distension, vomiting and potential aspiration events. Prokinetic agents are prescribed to improve gastric emptying. However, the efficacy and safety of these agents in critically ill patients is not well-defined. Therefore, we conducted a systematic review and meta-analysis to determine the efficacy and safety of prokinetic agents in critically ill patients. METHODS: We searched MEDLINE, EMBASE, and Cochrane Library from inception up to January 2016. Eligible studies included randomized controlled trials (RCTs) of critically ill adults assigned to receive a prokinetic agent or placebo, and that reported relevant clinical outcomes. Two independent reviewers screened potentially eligible articles, selected eligible studies, and abstracted pertinent data. We calculated pooled relative risk (RR) for dichotomous outcomes and mean difference for continuous outcomes, with the corresponding 95Â % confidence interval (CI). We assessed risk of bias using Cochrane risk of bias tool, and the quality of evidence using grading of recommendations assessment, development, and evaluation (GRADE) methodology. RESULTS: Thirteen RCTs (enrolling 1341 patients) met our inclusion criteria. Prokinetic agents significantly reduced feeding intolerance (RR 0.73, 95Â % CI 0.55, 0.97; Pâ=â0.03; moderate certainty), which translated to 17.3Â % (95Â % CI 5, 26.8Â %) absolute reduction in feeding intolerance. Prokinetics also reduced the risk of developing high gastric residual volumes (RR 0.69; 95Â % CI 0.52, 0.91; Pâ=â0.009; moderate quality) and increased the success of post-pyloric feeding tube placement (RR 1.60, 95Â % CI 1.17, 2.21; Pâ=â0.004; moderate quality). There was no significant improvement in the risk of vomiting, diarrhea, intensive care unit (ICU) length of stay or mortality. Prokinetic agents also did not significantly increase the rate of diarrhea. CONCLUSION: There is moderate-quality evidence that prokinetic agents reduce feeding intolerance in critically ill patients compared to placebo or no intervention. However, the impact on other clinical outcomes such as pneumonia, mortality, and ICU length of stay is unclear
Micronutrient fortification of food and its impact on woman and child health: A systematic review
Background: Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.Methods: A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.Results: Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.Conclusion: Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality
Traditional birth attendants (TBAs) as potential agents in promoting male involvement in maternity preparedness: insights from a rural community in Uganda
BACKGROUND: Since the 1994 International Conference on Population and Development, male involvement in reproductive health issues has been advocated as a means to improve maternal and child health outcomes, but to date, health providers have failed to achieve successful male involvement in pregnancy care especially in rural and remote areas where majority of the underserved populations live. In an effort to enhance community participation in maternity care, TBAs were trained and equipped to ensure better care and quick referral. In 1997, after the advent of the World Health Organizationâs Safe Motherhood initiative, the enthusiasm turned away from traditional birth attendants (TBAs). However, in many developing countries, and especially in rural areas, TBAs continue to play a significant role. This study explored the interaction between men and TBAs in shaping maternal healthcare in a rural Ugandan context. METHODS: This study employed ethnographic methods including participant observation, which took place in the process of everyday life activities of the respondents within the community; 12 focus group discussions, and 12 in-depth interviews with community members and key informants. Participants in this study were purposively selected to include TBAs, men, opinion leaders like village chairmen, and other key informants who had knowledge about the configuration of maternity services in the community. Data analysis was done inductively through an iterative process in which transcribed data was read to identify themes and codes were assigned to those themes. RESULTS: Contrary to the thinking that TBA services are utilized by women only, we found that men actively seek the services of TBAs and utilize them for their wivesâ healthcare within the community. TBAs in turn sensitize men using both cultural and biomedical health knowledge, and become allies with women in influencing men to provide resources needed for maternity care. CONCLUSION: In this study area, men trust and have confidence in TBAs; closer collaboration with TBAs may provide a suitable platform through which communities can be sensitized and men actively brought on board in promoting maternal health services for women in rural communities
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