848 research outputs found
Evaluation of implementation and effect of primary school based intervention to reduce risk factors for obesity
OBJECTIVES: To implement a school based health
promotion programme aimed at reducing risk factors
for obesity and to evaluate the implementation
process and its effect on the school.
DESIGN: Data from 10 schools participating in a group
randomised controlled crossover trial were pooled
and analysed.
SETTING: 10 primary schools in Leeds.
Participants 634 children (350 boys and 284 girls)
aged 7Â11 years.
MAIN OUTCOME MEASURES: Response rates to
questionnaires, teachers' evaluation of training and
input, success of school action plans, content of
school meals, and children's knowledge of healthy
living and self reported behaviour.
RESULTS: All 10 schools participated throughout the
study. 76 (89%) of the action points determined by
schools in their school action plans were achieved,
along with positive changes in school meals. A high
level of support for nutrition education and
promotion of physical activity was expressed by both
teachers and parents. 410 (64%) parents responded to
the questionnaire concerning changes they would like
to see implemented in school. 19 out of 20 teachers
attended the training, and all reported satisfaction
with the training, resources, and support. Intervention
children showed a higher score for knowledge,
attitudes, and self reported behaviour for healthy
eating and physical activity.
CONCLUSION: This programme was successfully
implemented and produced changes at school level
that tackled risk factors for obesity
Randomised controlled trial of primary school based intervention to reduce risk factors for obesity
OBJECTIVE: To assess if a school based intervention was
effective in reducing risk factors for obesity.
DESIGN: Group randomised controlled trial.
SETTING: 10 primary schools in Leeds.
PARTICIPANTS: 634 children aged 7Â-11 years.
INTERVENTION: Teacher training, modification of school
meals, and the development of school action plans
targeting the curriculum, physical education, tuck
shops, and playground activities.
MAIN OUTCOME MEASURES: Body mass index, diet,
physical activity, and psychological state.
RESULTS: Vegetable consumption by 24 hour recall was
higher in children in the intervention group than the
control group (weighted mean difference 0.3
portions/day, 95% confidence interval 0.2 to 0.4),
representing a difference equivalent to 50% of
baseline consumption. Fruit consumption was lower
in obese children in the intervention group ( - 1.0,
- 1.8 to - 0.2) than those in the control group. The
three day diary showed higher consumption of high
sugar foods (0.8, 0.1 to 1.6)) among overweight
children in the intervention group than the control
group. Sedentary behaviour was higher in overweight
children in the intervention group (0.3, 0.0 to 0.7).
Global self worth was higher in obese children in the
intervention group (0.3, 0.3 to 0.6). There was no
difference in body mass index, other psychological
measures, or dieting behaviour between the groups.
Focus groups indicated higher levels of self reported
behaviour change, understanding, and knowledge
among children who had received the intervention.
CONCLUSION: Although it was successful in producing
changes at school level, the programme had little
effect on children's behaviour other than a modest
increase in consumption of vegetables
Points of Low Height on Elliptic Curves and Surfaces, I: Elliptic surfaces over P^1 with small d
For each of n=1,2,3 we find the minimal height h^(P) of a nontorsion point P
of an elliptic curve E over C(T) of discriminant degree d=12n (equivalently, of
arithmetic genus n), and exhibit all (E,P) attaining this minimum. The minimal
h^(P) was known to equal 1/30 for n=1 (Oguiso-Shioda) and 11/420 for n=2
(Nishiyama), but the formulas for the general (E,P) were not known, nor was the
fact that these are also the minima for an elliptic curve of discriminant
degree 12n over a function field of any genus. For n=3 both the minimal height
(23/840) and the explicit curves are new. These (E,P) also have the property
that that mP is an integral point (a point of naive height zero) for each
m=1,2,...,M, where M=6,8,9 for n=1,2,3; this, too, is maximal in each of the
three cases.Comment: 15 pages; some lines in the TeX source are commented out with "%" to
meet the 15-page limit for ANTS proceeding
Shimura curve computations via K3 surfaces of Neron-Severi rank at least 19
It is known that K3 surfaces S whose Picard number rho (= rank of the
Neron-Severi group of S) is at least 19 are parametrized by modular curves X,
and these modular curves X include various Shimura modular curves associated
with congruence subgroups of quaternion algebras over Q. In a family of such K3
surfaces, a surface has rho=20 if and only if it corresponds to a CM point on
X. We use this to compute equations for Shimura curves, natural maps between
them, and CM coordinates well beyond what could be done by working with the
curves directly as we did in ``Shimura Curve Computations'' (1998) =
Comment: 16 pages (1 figure drawn with the LaTeX picture environment); To
appear in the proceedings of ANTS-VIII, Banff, May 200
Oxygen impurities in NiAl: Relaxation effects
We have used a full-potential linear muffin-tin orbital method to calculate
the effects of oxygen impurities on the electronic structure of NiAl. Using the
supercell method with a 16-atom supercell we have investigated the cases where
an oxygen atom is substitutionally placed at either a nickel or an aluminum
site. Full relaxation of the atoms within the supercell was allowed. We found
that oxygen prefers to occupy a nickel site over an aluminum site with a site
selection energy of 138 mRy (21,370 K). An oxygen atom placed at an aluminum
site is found to cause a substantial relaxation of its nickel neighbors away
from it. In contrast, this steric repulsion is hardly present when the oxygen
atom occupies the nickel site and is surrounded by aluminum neighbors. We
comment on the possible relation of this effect to the pesting degradation
phenomenon (essentially spontaneous disintegration in air) in nickel
aluminides.Comment: To appear in Phys. Rev. B (Aug. 15, 2001
Unscreened Hartree-Fock calculations for metallic Fe, Co, Ni, and Cu from ab-initio Hamiltonians
Unscreened Hartree-Fock approximation (HFA) calculations for metallic Fe, Co,
Ni, and Cu are presented, by using a quantum-chemical approach. We believe that
these are the first HFA results to have been done for crystalline 3d transition
metals. Our approach uses a linearized muffin-tin orbital calculation to
determine Bloch functions for the Hartree one-particle Hamiltonian, and from
these obtains maximally localized Wannier functions, using a method proposed by
Marzari and Vanderbilt. Within this Wannier basis all relevant one-particle and
two-particle Coulomb matrix elements are calculated. The resulting
second-quantized multi-band Hamiltonian with ab-initio parameters is studied
within the simplest many-body approximation, namely the unscreened,
self-consistent HFA, which takes into account exact exchange and is free of
self-interactions. Although the d-bands sit considerably lower within HFA than
within the local (spin) density approximation L(S)DA, the exchange splitting
and magnetic moments for ferromagnetic Fe, Co, and Ni are only slightly larger
in HFA than what is obtained either experimentally or within LSDA. The HFA
total energies are lower than the corresponding LSDA calculations. We believe
that this same approach can be easily extended to include more sophisticated
ab-initio many-body treatments of the electronic structure of solids.Comment: 11 papes, 7 figures, 5 table
Leprosy Post-Exposure Prophylaxis (LPEP) programme: Study protocol for evaluating the feasibility and impact on case detection rates of contact tracing and single dose rifampicin
Introduction: The reported number of new leprosy patients has barely changed in recent years. Thus, additional approaches or modifications to the current standard of passive case detection are needed to interrupt leprosy transmission. Large-scale clinical trials with single dose rifampicin (SDR) given as post-exposure prophylaxis (PEP) to contacts of newly diagnosed patients with leprosy have shown a 50-60% reduction of the risk of developing leprosy over the following 2 years. To accelerate the uptake of this evidence and introduction of PEP into national leprosy programmes, data on the effectiveness, impact and feasibility of contact tracing and PE
Numerical properties of isotrivial fibrations
In this paper we investigate the numerical properties of relatively minimal
isotrivial fibrations \varphi \colon X \lr C, where is a smooth,
projective surface and is a curve. In particular we prove that, if and is neither ruled nor isomorphic to a quasi-bundle, then K_X^2
\leq 8 \chi(\mO_X)-2; this inequality is sharp and if equality holds then
is a minimal surface of general type whose canonical model has precisely two
ordinary double points as singularities. Under the further assumption that
is ample, we obtain K_X^2 \leq 8 \chi(\mO_X)-5 and the inequality is
also sharp. This improves previous results of Serrano and Tan.Comment: 30 pages. Final version, to appear in Geometriae Dedicat
Quasars and their host galaxies
This review attempts to describe developments in the fields of quasar and
quasar host galaxies in the past five. In this time period, the Sloan and 2dF
quasar surveys have added several tens of thousands of quasars, with Sloan
quasars being found to z>6. Obscured, or partially obscured quasars have begun
to be found in significant numbers. Black hole mass estimates for quasars, and
our confidence in them, have improved significantly, allowing a start on
relating quasar properties such as radio jet power to fundamental parameters of
the quasar such as black hole mass and accretion rate. Quasar host galaxy
studies have allowed us to find and characterize the host galaxies of quasars
to z>2. Despite these developments, many questions remain unresolved, in
particular the origin of the close relationship between black hole mass and
galaxy bulge mass/velocity dispersion seen in local galaxies.Comment: Review article, to appear in Astrophysics Update
Supermassive Black Hole Binaries: The Search Continues
Gravitationally bound supermassive black hole binaries (SBHBs) are thought to
be a natural product of galactic mergers and growth of the large scale
structure in the universe. They however remain observationally elusive, thus
raising a question about characteristic observational signatures associated
with these systems. In this conference proceeding I discuss current theoretical
understanding and latest advances and prospects in observational searches for
SBHBs.Comment: 17 pages, 4 figures. To appear in the Proceedings of 2014 Sant Cugat
Forum on Astrophysics. Astrophysics and Space Science Proceedings, ed.
C.Sopuerta (Berlin: Springer-Verlag
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