243 research outputs found
Preliminary nitrite, nitrate and colour analysis of Malaysian edible birdâs nest
AbstractThe high nitrite content in edible birdâs nests is a major concern to the local swiftlet industry. It lowers the price of the edible birdâs nests and it brings severe health hazards to consumers and farmers. This research investigated the nitrite and nitrate contents of eight types of local edible birdâs nests by using ion chromatography system and evaluating its colour using the CIE system in Lâaâbâ parameters. The nitrite content obtained ranged from 5.7ÎŒg/g for the house nests to 843.8ÎŒg/g for the cave nests. The nitrate content for the house and cave nests was 98.2ÎŒg/g and 36,999.4ÎŒg/g, respectively. The cave nests with darker and redder colour had higher nitrite and nitrate contents than the brighter and more yellow house nests. This likely suggests that the nitrite and nitrate contents have correlations with edible birdâs nests colour. Correlations studies suggested that the nitrite content had high correlations with colour parameters, Lâaâbâ of edible birdâs nests at significant level of P<0.10. These findings suggest that edible birdâs nestsâ colour may be a useful indicator for measuring nitrite and nitrate contaminations
Birth Weight, Infant Growth, and Childhood Body Mass Index: Hong Kongâs Children of 1997 Birth Cohort
ObjectiveTo investigate the association between birth weight, infant growth rate, and childhood adiposity as a proxy for adult metabolic or cardiovascular risk in a Chinese population with a history of recent and rapid economic development.
DesignProspective study in a population-representative birth cohort.
SettingHong Kong Chinese population.
ParticipantsSix thousand seventy-five term births (77.5% successful follow-up).
Main ExposuresBirth weight and growth rate (change in the weight z score) at ages 0 to 3 and 3 to 12 months.
Main Outcome Measure: Body mass index (BMI) (calculated as the weight in kilograms divided by the height in meters squared) z score at about age 7 years.
ResultsEach unit increase in the weight z score at ages 0 to 3 and 3 to 12 months increased the BMI z score by 0.52 and 0.33, respectively. Children in the highest birth weight and growth rate tertiles had the highest BMI z scores. In the lowest birth weight tertile, increases in the weight z score at ages 0 to 3 months had a larger effect on the BMI z score in boys (mean difference, 0.88; 95% confidence interval 0.69-1.07) than in girls (mean difference, 0.52; 95% confidence interval, 0.33-0.71); these differences by birth weight, growth rate at ages 0 to 3 months, and sex were significant (P=.007).
Conclusions Faster prenatal and postnatal growth were associated with higher childhood BMI in a population with a recent history of rapid economic growth and relatively low birth weight, suggesting that maximal growth may not be optimal for metabolic risk. However, there may be a developmental trade-off between metabolic risk and other outcomes
Evaluation of a virtual reality based interactive simulator with haptic feedback for learning NGT placement
Background The placement of a nasogastric tube is a blind process; the tube may be mistakenly inserted into other locations, leading to possible complications or fatal incidents. Effective education and training of nursing students to perform this procedure is essential. Purpose To investigate the application of the virtual reality based simulator with haptic feedback to nursing students for their learning around nasogastric tube placement. Methods A quasi-experimental non-equivalent group pre- and post-test study, in which the outcome measures of two classes of pre-registration nursing students were compared for their evidence of learning about the advanced NGT simulator (in addition to usual training) against the control group who only used mannequins for their usual education and training. Results There was a decrease, though remaining at a good level, in the technology acceptance rating within (p = .000) and between (p < .05) the simulator group than the control over time at post-test. Taking into consideration of some demographic differences at baseline between the two groups, analysis of results demonstrated that there was no predictor effect of those factors in relation to technology acceptance (F = .02, p = .922), but in scores for the test using multiple-choice questions (MCQ) about knowledge in nasogastric tube insertion (F = 23.4, p = .000). Both groups demonstrated significant increases in MCQ scores at post-test, with higher scores in the simulator group at both pre-test (p < .05) and post-test (p = .000). There was no significant difference in learning outcomes around competence in skills within the evaluation results between groups at post-test. Usability of the simulator system as rated by the simulator group was good. Conclusions Students did not reject the use of the new simulator for their learning about nasogastric tube placement. As an adjunct to conventional teaching and learning, the use of the simulator appears to be promising in enhancing the education and training of nursing students for development of the important clinical skill of safe nasogastric tube placement. Future studies are warranted, with the design inclusive of equivalent groups and a larger sample size to further the evidence in substantiating the use of this simulator for better learning outcomes
The cooling of atomic and molecular gas in DR21
We present an overview of a high-mass star formation region through the major
(sub-)mm, and far-infrared cooling lines to gain insight into the physical
conditions and the energy budget of the molecular cloud. We used the KOSMA 3m
telescope to map the core () of the Galactic star forming region
DR 21/DR 21 (OH) in the Cygnus X region in the two fine structure lines of
atomic carbon CI and four mid- transitions of CO and CO, and CS
J=7\TO6. These observations have been combined with FCRAO J=1\TO0
observations of CO and CO. Five positions, including DR21, DR21
(OH), and DR21 FIR1, were observed with the ISO/LWS grating spectrometer in the
\OI 63 and 145 m lines, the \CII 158 m line, and four high- CO
lines. We discuss the intensities and line ratios at these positions and apply
Local Thermal Equilibrium (LTE) and non-LTE analysis methods in order to derive
physical parameters such as masses, densities and temperatures. The CO line
emission has been modeled up to J=20. From non-LTE modeling of the low- to
high- CO lines we identify two gas components, a cold one at temperatures of
T_\RM{kin}\sim 30-40 K, and one with T_\RM{kin}\sim 80-150 K at a local
clump density of about n(H) cm. While the cold
quiescent component is massive containing typically more than 94 % of the mass,
the warm, dense, and turbulent gas is dominated by mid- and high- CO line
emission and its large line widths. The medium must be clumpy with a
volume-filling of a few percent. The CO lines are found to be important for the
cooling of the cold molecular gas, e.g. at DR21 (OH). Near the outflow of the
UV-heated source DR21, the gas cooling is dominated by line emission of atomic
oxygen and of CO
Self-consistent calculation of total energies of the electron gas using many-body perturbation theory
The performance of many-body perturbation theory for calculating ground-state properties is investigated. We present fully numerical results for the electron gas in three and two dimensions in the framework of the GW approximation. The overall agreement with very accurate Monte Carlo data is excellent, even for those ranges of densities for which the GW approach is often supposed to be unsuitable. The latter seems to be due to the fulfillment of general conservation rules. These results open further prospects for accurate calculations of ground-state properties circumventing the limitations of standard density-functional theory
Cultural threats in culturally mixed encounters hamper creative performance for individuals with lower openness to experience
Ministry of Education, Singapore under its Academic Research Funding Tier
Monte Carlo radiative transfer in molecular cloud cores
We present the results of a three-dimensional Monte Carlo radiative transfer
code for starless molecular cloud cores heated by an external isotropic or
non-isotropic interstellar radiation field. The code computes the dust
temperature distribution inside model clouds with specified but arbitrary
density profiles. In particular we examine in detail spherical (Bonnor-Ebert)
clouds, axisymmetric and non-axisymmetric toroids, and clouds heated by an
external stellar source in addition to the general interstellar field. For
these configurations, the code also computes maps of the emergent intensity at
different wavelengths and arbitrary viewing angle, that can be compared
directly with continuum maps of prestellar cores. In the approximation where
the dust temperature is independent of interactions with the gas and where the
gas is heated both by collisions with dust grains and ionization by cosmic
rays, the temperature distribution of the gas is also calculated. For cloud
models with parameters typical of dense cores, the results show that the dust
temperature decreases monotonically from a maximum value near the cloud's edge
(14-15 K) to a minimum value at the cloud's center (6-7 K). Conversely, the gas
temperature varies in a similar range, but, due to efficient dust-gas coupling
in the inner regions and inefficient cosmic-ray heating in the outer regions,
the gradient is non-monotonic and the gas temperature reaches a maximum value
at intermediate radii. The emission computed for these models (at 350 micron
and 1.3 mm) shows that deviations from spherical symmetry in the density and/or
temperature distributions are generally reduced in the simulated intensity maps
(even without beam convolution), especially at the longer wavelengths.Comment: 12 pages, 6 figures. Astronomy and Astrophysics, in pres
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