31,215 research outputs found
Efficient FDTD-PE model for sound propagation in situations with complex obstacles and wind profiles
Long-term effects of a weight loss intervention with or without exercise component in postmenopausal women: a randomized trial
The aim of this study was to determine the long-term effects of a weight loss intervention with or without an exercise component on body weight and physical activity. Women were randomized to diet (n = 97) or exercise (N = 98) for 16 weeks. During the intervention, both groups had achieved the set goal of 5-6 kg weight loss. All women were re-contacted twelve months after study cessation for follow-up where body weight and physical activity were measured (PASE questionnaire and ActiGraph accelerometer). At follow-up, body weight and physical activity (measured by the PASE questionnaire and accelerometer) were measured again. At follow-up, both mainly exercise (- 4.3 kg, p < 0.001) and diet (- 3.4 kg, p < 0.001) showed significantly reduced body weight compared to baseline. Both the mainly exercise and diet group were significantly more physically active at one year follow-up compared to baseline (PASE: + 33%, p < 0.001 and + 12%, p = 0.040, respectively; ActiGraph: + 16%, p = 0.012. and + 2.2%, p = 0.695 moderate-to-vigorous activity, respectively). Moreover, the increase in physical activity was statistically significantly when comparing exercise to diet (+ 0.6%, p = 0.035). ActiGraph data also showed significantly less sedentary time in mainly exercise group compared to baseline (- 2.1%, p = 0.018) and when comparing exercise to diet (- 1.8%, p = 0.023). No significant within group differences were found for the diet group. This study shows largely sustained weight loss one year after completing a weight loss program with and without exercise in overweight postmenopausal women. Although the mainly exercise group maintained more physically active compared to the diet group, maintenance of weight loss did not differ between groups
Developmental screening in South Africa : comparing the national developmental checklist to a standardized tool
Background: Worldwide, more than 200 million children in low- and middle-income countries have developmental delays and/or disabilities. In South Africa the only nationally implemented developmental 'screening' tool is integrated as part of 'The Road to Health Booklet (RTHB).
Method: The study employed a comparative cross-sectional within-subject design to evaluate the accuracy of the RTHB developmental checklist against a standardized international tool i.e. the PEDS tools, consisting of the PEDS and PEDS: DM. A total of 201 participants were included through convenience sampling at primary health care facilities in Tshwane, South Africa.
Results: Sensitivity of the RTHB developmental checklist is low, but specificity is high. The RTHB developmental checklist failed to identify more than half the infants at risk of delays or disorders. The nationally implemented developmental checklist is ineffective to identify at-risk infants. It should be adapted and validated or replaced in order to improve identification of at-risk infants
A Family of Quantum Stabilizer Codes Based on the Weyl Commutation Relations over a Finite Field
Using the Weyl commutation relations over a finite field we introduce a
family of error-correcting quantum stabilizer codes based on a class of
symmetric matrices over the finite field satisfying certain natural conditions.
When the field is GF(2) the existence of a rich class of such symmetric
matrices is demonstrated by a simple probabilistic argument depending on the
Chernoff bound for i.i.d symmetric Bernoulli trials. If, in addition, these
symmetric matrices are assumed to be circulant it is possible to obtain
concrete examples by a computer program. The quantum codes thus obtained admit
elegant encoding circuits.Comment: 16 pages, 2 figure
Finite Schur filtration dimension for modules over an algebra with Schur filtration
Let G be GL_N or SL_N as reductive linear algebraic group over a field k of
positive characteristic p. We prove several results that were previously
established only when N 2^N. Let G act rationally on a finitely
generated commutative k-algebra A. Assume that A as a G-module has a good
filtration or a Schur filtration. Let M be a noetherian A-module with
compatible G action. Then M has finite good/Schur filtration dimension, so that
there are at most finitely many nonzero H^i(G,M). Moreover these H^i(G,M) are
noetherian modules over the ring of invariants A^G. Our main tool is a
resolution involving Schur functors of the ideal of the diagonal in a product
of Grassmannians.Comment: 22 pages; final versio
Mentorship by commercial farmers in the land reform programme in the Free State Province
This study evaluates commercial farmers’ views of their role as mentors in the land reform programme in two regions of the Free State Province. It reveals that the majority of commercial farmers in the study area are willing to act as mentors. The farmers overwhelmingly agreed that their role as mentors is very important. On average, the farmers were willing to participate in the mentorship programme and most of them expect to receive remuneration for their work as mentors. A little over two thirds of the farmers believe that the extension services play a vital role in the development of emerging farmers, while others indicated that they were not satisfied with the current advisory service. The study recommends that before any agreement is entered into with any mentor a guide should be developed to ensure that priority areas are taken care of in order to avoid conflict at a later stage.Key words: Evaluation, Commercial farmers, Mentorshi
Learning at home: an ethnographic study of a South African home school
Home schooling may be defined as an alternative to on-site institutionalised schooling. Most education systems accommodate home schooling but such arrangements are regulated in various ways. This article reports on an investigation into home schooling in South Africa as an consequential part of the education system of the country. A literature review of the context, nature, scope and current issues of the home schooling movement, in other countries as well as in South Africa, is presented as background to the empirical investigation. The latter comprised an ethnographic study of a single home-schooling family chosen by judgement sampling. Data were collected during a six-month period of fieldwork employing participant observation and semi-structured interviews. The findings showed that although home schooling is an effective model of education and is rewarding for many families, it requires extensive commitment, dedication, preparation, emotional involvement and stamina.
South African Journal of Education Vol.24(1) 2004: 18-2
- …