388 research outputs found
Determinants of Student Absenteeism/Presenteeism in Qatar: A Path Analysis
The current study sought to investigate the perceptions of school teachers regarding student absenteeism and presenteeism in the State of Qatar. Drawing on the existing relevant literature in the field and based on a survey research method, the study was carried out during the first term (Fall semester) in 2015. The study involved preparatory (middle) and secondary (high) school teachers at both public (Independent) and private (International) schools in Qatar. To attain this goal, a causal model was used to examine the causes that shape teachers’ perceptions of absenteeism and presenteeism. The data required for the present research was collected from a sample of 495 teachers at Independent and International schools. Based on factor analysis, the findings concluded from the study indicated that seven valid dimensions were extracted. In addition, three determinant factors that influence the perceptions of preparatory and secondary school teachers with regard to students’ absentee and presentee behaviours were identified. These factors are: (a) reviewing curriculum content, (b) the teaching load, and (c) the expected rate of student graduations. The study concludes by offering some important recommendations for education practitioners and policy makers as well as some useful suggestions for future research and practice
Rhinobatos annandalei, Bengal Guitarfish
The Bengal Guitarfish (Rhinobatos annandalei) is a small (to 95 cm total length) guitarfish that occurs in
the northern Indian Ocean from the United Arab Emirates (UAE) to Bangladesh, including Sri Lanka. The
western boundary of this species distribution is uncertain due to confusion with the Spotted Guitarfish
(R. punctifer). It is demersal on the inner continental shelf at depths of 5–73 m. The species is mainly a
bycatch of a range of industrial and artisanal gears including demersal trawls, longlines, and gillnets. The
meat is consumed locally and traded internationally, and the skins are exported from Bangladesh to
Myanmar to be made into accessories (e.g. handbags). There is a high level of fisheries resource use and
increasing fishing pressure across the range of this species. Severe population reduction is inferred from
actual levels of exploitation, as well as several historical accounts and contemporary datasets from the
UAE, Iran, Pakistan, and India. Landings data of guitarfishes and rays from the UAE, Iran, Pakistan, India,
and Bangladesh indicate landings declines of 69–93% consistent with population reductions of 80% over
the past three generation lengths (27 years). These levels of declines are not species-specific but are
informative for understanding the broader levels of guitarfish decline in the region. It is suspected that
the Bengal Guitarfish has undergone a population reduction of >80% over the past three generation
lengths (27 years) due to actual levels of exploitation, and it is assessed as Critically Endangered A2d
Feasibility and acceptability of a technology-based, rural weight management int ervention in older adults with obesity
Background
Older adults with obesity residing in rural areas have reduced access to weight management programs. We determined the feasibility, acceptability and preliminary outcomes of an integrated technology-based health promotion intervention in rural-living, older adults using remote monitoring and synchronous video-based technology. Methods
A 6-month, non-randomized, non-blinded, single-arm study was conducted from October 2018 to May 2020 at a community-based aging center of adults aged ≥65 years with a body mass index (BMI) ≥30 kg/m2. Weekly dietitian visits focusing on behavior therapy and caloric restriction and twice-weekly physical therapist-led group strength, flexibility and balance training classes were delivered using video-conferencing to participants in their homes. Participants used a Fitbit Alta HR for remote monitoring with data feedback provided by the interventionists. An aerobic activity prescription was provided and monitored. Results
Mean age was 72.9±3.9 years (82% female). Baseline anthropometric measures of weight, BMI, and waist circumference were 97.8±16.3 kg, 36.5±5.2 kg/m2, and 115.5±13.0 cm, respectively. A total of 142 participants were screened (n=27 ineligible), and 53 consented. There were nine dropouts (17%). Overall satisfaction with the trial (4.7+ 0.6, scale: 1 (low) to 5 (high)) and with Fitbit (4.2+ 0.9) were high. Fitbit was worn an average of 81.7±19.3% of intervention days. In completers, mean weight loss was 4.6±3.5 kg or 4.7±3.5% (p\u3c 0.001). Physical function measures of 30-s sit-to-stand repetitions increased from 13.5±5.7 to 16.7±5.9 (p\u3c 0.001), 6-min walk improved by 42.0±77.3 m (p=0.005) but no differences were observed in gait speed or grip strength. Subjective measures of late-life function improved (3.4±4.7 points, p\u3c 0.001). Conclusions
A technology-based obesity intervention is feasible and acceptable to older adults with obesity and may lead to weight loss and improved physical function. Clinical trial registration
Registered on Clinicaltrials.gov #NCT03104205. Registered on April 7, 2017. First participant enrolled on October 1st, 2018
Carcharhinus hemiodon Pondicherry Shark
The Pondicherry Shark (Carcharhinus hemiodon) is a small (to 102 cm total length) and very rare Indo-
West Pacific whaler shark. It has a wide historic range from Oman to southern China, but known records
are scattered, and it has only been reliably verified from a handful of countries. It appears to occur in
shallow coastal waters, and has also been reported to enter rivers, although this has not been verified.
The contemporary range of this species is poorly defined and museum specimens were collected pre-
1960. There are reports from 1979, the 1990s, and 2000, but none of these could be verified. Its
identification is problematic, and it is easily confused with a number of other Carcharhinus species (for
example, recent putative records from Sri Lanka)
Enhanced insulin sensitivity associated with provision of mono and polyunsaturated fatty acids in skeletal muscle cells involves counter modulation of PP2A
International audienceAims/Hypothesis: Reduced skeletal muscle insulin sensitivity is a feature associated with sustained exposure to excess saturated fatty acids (SFA), whereas mono and polyunsaturated fatty acids (MUFA and PUFA) not only improve insulin sensitivity but blunt SFA-induced insulin resistance. The mechanisms by which MUFAs and PUFAs institute these favourable changes remain unclear, but may involve stimulating insulin signalling by counter-modulation/repression of protein phosphatase 2A (PP2A). This study investigated the effects of oleic acid (OA; a MUFA), linoleic acid (LOA; a PUFA) and palmitate (PA; a SFA) in cultured myotubes and determined whether changes in insulin signalling can be attributed to PP2A regulation. Principal Findings: We treated cultured skeletal myotubes with unsaturated and saturated fatty acids and evaluated insulin signalling, phosphorylation and methylation status of the catalytic subunit of PP2A. Unlike PA, sustained incubation of rat or human myotubes with OA or LOA significantly enhanced Akt-and ERK1/2-directed insulin signalling. This was not due to heightened upstream IRS1 or PI3K signalling nor to changes in expression of proteins involved in proximal insulin signalling, but was associated with reduced dephosphorylation/inactivation of Akt and ERK1/2. Consistent with this, PA reduced PP2Ac demethylation and tyrosine 307 phosphorylation-events associated with PP2A activation. In contrast, OA and LOA strongly opposed these PA-induced changes in PP2Ac thus exerting a repressive effect on PP2A.Conclusions/Interpretation: Beneficial gains in insulin sensitivity and the ability of unsaturated fatty acids to oppose palmitate-induced insulin resistance in muscle cells may partly be accounted for by counter-modulation of PP2A
Scoliodon laticaudus, Spadenose Shark
The Spadenose Shark (Scoliodon laticaudus) is a small (to 91 cm total length) shark that occurs in the
northern Indian Ocean from the Gulf of Oman to Myanmar. It is common in coastal and estuarine waters
at depths of 10-75 m, but more typically less than 50 m and prefers muddy and sandy substrates and
often occurs near large freshwater outflows. It is highly productive with annual large litters of 6–20
pups, early maturation at two years and a short generation length of 4.5 years. The species is caught
mainly by trawl and gillnet in industrial and artisanal fisheries and is retained for human consumption. It
is the dominant shark landed in Pakistan, northern India, and Bangladesh and fishing pressure is intenseacross most of its range. The high productivity of the species and short generation length likely provide
it with resilience to fishing pressure, however, the intense and ongoing fishing pressure on this species is
a cause for concern. It is suspected that the Spadenose Shark has undergone a population reduction of
20–29% over the past three generation lengths (14 years) and is close to reaching the population
reduction threshold due to levels of exploitation, and it is assessed as Near Threatened (nearly meeting
Vulnerable A2d)
Overfishing Drives Over One-Third of All Sharks and Rays Toward a Global Extinction Crisis
The scale and drivers of marine biodiversity loss are being revealed by the International Union for Conservation of Nature (IUCN) Red List assessment process. We present the first global reassessment of 1,199 species in Class Chondrichthyes-sharks, rays, and chimeras. The first global assessment (in 2014) concluded that one-quarter (24%) of species were threatened. Now, 391 (32.6%) species are threatened with extinction. When this percentage of threat is applied to Data Deficient species, more than one-third (37.5%) of chondrichthyans are estimated to be threatened, with much of this change resulting from new information. Three species are Critically Endangered (Possibly Extinct), representing possibly the first global marine fish extinctions due to overfishing. Consequently, the chondrichthyan extinction rate is potentially 25 extinctions per million species years, comparable to that of terrestrial vertebrates. Overfishing is the universal threat affecting all 391 threatened species and is the sole threat for 67.3% of species and interacts with three other threats for the remaining third: loss and degradation of habitat (31.2% of threatened species), climate change (10.2%), and pollution (6.9%). Species are disproportionately threatened in tropical and subtropical coastal waters. Science-based limits on fishing, effective marine protected areas, and approaches that reduce or eliminate fishing mortality are urgently needed to minimize mortality of threatened species and ensure sustainable catch and trade of others. Immediate action is essential to prevent further extinctions and protect the potential for food security and ecosystem functions provided by this iconic lineage of predators
Fitting censored quantile regression by variable neighborhood search
Quantile regression is an increasingly important topic in statistical analysis. However, fitting censored quantile regression is hard to solve numerically because the objective function to be minimized is not convex nor concave in regressors. Performance of standard methods is not satisfactory, particularly if a high degree of censoring is present. The usual approach is to simplify (linearize) estimator function, and to show theoretically that such approximation converges to optimal values. In this paper, we suggest a new approach, to solve optimization problem (nonlinear, nonconvex, and nondifferentiable) directly. Our method is based on variable neighborhood search approach, a recent successful technique for solving global optimization problems. The presented results indicate that our method can improve quality of censored quantizing regressors estimator considerably
Patient attitudes towards medical students at Damascus University teaching hospitals
Background: The cooperation of patients and their consent to involve medical students in their care is vital to clinical education, but large numbers of students and lack of experience as well as loss of privacy may evoke negative attitudes of patients, which may sometimes adversely affect the clinical teaching environment. This study aimed to explore the attitudes of patients towards medical students at Damascus University hospitals, and to explore the determinants of those attitudes thus discussing possible implications applicable to clinical teaching. Methods: This cross-sectional study was conducted at three teaching hospitals affiliated to the Faculty of Medicine at Damascus University. Four hundred patients were interviewed between March and April 2011 by a trained sociologist using a structured questionnaire. Results: Of the patients interviewed, 67.8 % approved the presence of medical students during the medical consultation and 58.2 % of them felt comfortable with the presence of students, especially among patients with better socio-economic characteristics. 81.5 % of the patients agreed to be examined by students in the presence of the supervisor, while 40.2 % gave agreement even in the absence of the supervisor. Privacy was the most important factor in the patients ’ reticence towards examination by the students, whilst the relative safety and comfort if a supervisor was available determined patients ’ agreement
- …