564 research outputs found
Thermal tolerance of allis shad (Alosa alosa) embryos and larvae: Modeling and potential applications
International audienceThe objective of this study was to assess the potential effects of climate change on the survival of allis shad early life history stages. Embryos and larvae were exposed to temperatures ranging from 5 to 35 °C. No embryonic survival was recorded at extreme temperatures (≤10 and ≥30 °C), and no larval survival was observed at 5 or 35 °C. Based on these experimental results, a survival model was developed to predict survival rates at different temperatures for embryos and larvae up to 14 days post hatch. The model confirmed that embryonic daily survival is more impacted by temperature than larval survival. The highest survival rates (greater than 80%) were found for temperatures between 15.7 and 25.6 °C for embryos and between 14.6 and 26.7 °C for larvae. This survival model can be used to explore the impact of temperature on recruitment of allis shad in southern France. Preliminary analysis from two different rivers suggests that cold temperatures may have a strong impact on embryonic and larval survival
Parenting style, the home environment, and screen time of 5-year-old children; the 'be active, eat right' study
Introduction: The global increase in childhood overweight and obesity has been ascribed partly to increases in children's screen time. Parents have a large influence on their children's screen time. Studies investigating parenting and early childhood screen time are limited. In this study, we investigated associations of parenting style and the social and physical home environment on watching TV and using computers or game consoles among 5-year-old children. Methods: This study uses baseline data concerning 5-year-old children (n = 3067) collected for the 'Be active, eat right' study. Results: Children of parents with a higher score on the parenting style dimension involvement, were more likely to spend >30 min/day on computers or game consoles. Overall, families with an authoritative or authoritarian parenting style had lower percentages of children's screen time compared to families with an indulgent or neglectful style, but no significant difference in OR was found. In families with rules about screen time, children were less likely to watch TV>2 hrs/day and more likely to spend >30 min/day on computers or game consoles. The number of TVs and computers or game consoles in the household was positively associated with screen time, and children with a TV or computer or game console in their bedroom were more likely to watch TV>2 hrs/day or spend >30 min/day on computers or game consoles. Conclusion: The magnitude of the association between parenting style and screen time of 5-year-olds was found to be relatively modest. The associations found between the social and physical environment and children's screen time are independent of parenting style. Interventions to reduce children's screen time might be most effective when they support parents specifically with introducing family rules related to screen time and prevent the presence of a TV or computer or game console in the child's room
Physical properties of ESA Rosetta target asteroid (21) Lutetia: Shape and flyby geometry
Aims. We determine the physical properties (spin state and shape) of asteroid
(21) Lutetia, target of the ESA Rosetta mission, to help in preparing for
observations during the flyby on 2010 July 10 by predicting the orientation of
Lutetia as seen from Rosetta.
Methods. We use our novel KOALA inversion algorithm to determine the physical
properties of asteroids from a combination of optical lightcurves,
disk-resolved images, and stellar occultations, although the latter are not
available for (21) Lutetia.
Results. We find the spin axis of (21) Lutetia to lie within 5 degrees of
({\lambda} = 52 deg., {\beta} = -6 deg.) in Ecliptic J2000 reference frame
(equatorial {\alpha} = 52 deg., {\delta} = +12 deg.), and determine an improved
sidereal period of 8.168 270 \pm 0.000 001 h. This pole solution implies the
southern hemisphere of Lutetia will be in "seasonal" shadow at the time of the
flyby. The apparent cross-section of Lutetia is triangular as seen "pole-on"
and more rectangular as seen "equator-on". The best-fit model suggests the
presence of several concavities. The largest of these is close to the north
pole and may be associated with large impacts.Comment: 17 pages, 5 figures, 3 tables, submitted to Astronomy and
Astrophysic
The Terneuzen Birth Cohort: BMI Changes between 2 and 6 Years Correlate Strongest with Adult Overweight
Background: Complications of overweight amplify with age, and irreversible damage already exists in young persons. Identifying the most sensitive age interval(s) for adult overweight is relevant for primary prevention. The aim of the study was to assess the relative contribution of body mass index (BMI) changes between 0 and 18 years to adult overweight, and to identify the earliest critical growth period. Methods and Findings: Data from 762 subjects in the Terneuzen Birth Cohort with an average of 21 growth measurements per subject from birth until 18 years were used. The main outcome measure was the BMI standard deviation score (SDS) at young adulthood. For each subject BMI SDS was fitted by a piecewise linear model at eight different ages and correlated to adult BMI SDS. The age intervals in between are considered critical according to three criteria, tested by respectively Students' t-tests, multiple linear regression analyses and Pearson's correlation tests. In the age intervals 4 months(m) -1 year(y), 2-6 y, 6-10 y and 10-18 y the BMI SDS change differs between adults with and without overweight (P≤0.001). The age intervals 2-6 y and 10-18 y also meet the second criterion, implying that the BMI change during this period has a predictive value for adult BMI SDS in addition to BMI SDS at the end of the period. The largest rise in correlation between estimated BMI SDS and measured adult BMI SDS occurs during the period 2-6 y (from 0.36 to 0.63), which results in a high sensitivity (0.6) and specificity (0.8) by the age of 6 y. Conclusions/Significance: The age interval from 2 y to 6 y is the earliest and most critical growth period for adult overweight. Therefore, primary prevention of adult overweight seems most likely to be successful if targeted at this specific age interval. By identifying those with an upwards centile crossing between 2 and 6 years, the development towards adult overweight might be reversed. © 2010 De Kroon et al
Efficacy of the Young Women's CoOp: An HIV Risk-Reduction Intervention for Substance-Using African-American Female Adolescents in the South
HIV/sexually transmitted infection (STI) risk-reduction interventions are needed to address the complex risk behaviors among African-American female adolescents in disadvantaged communities in North Carolina. In a two-group randomized trial, we reached 237 sexually active, substance-using African-American female adolescents, to test a risk-reduction intervention, the Young Women’s CoOp (YWC), relative to a nutrition control. In efficacy analyses adjusting for baseline condom use, at three-month follow-up participants in the YWC were significantly less likely to report sex without a condom at last sex relative to control. There were mixed findings for within-group differences over follow-up, underscoring the challenges for intervening with substance-using female youths
Speckle observations of the binary asteroid (22) Kalliope with C2PU/PISCO
We present new speckle measurements of the position of Linus, the satellite
of the asteroid (22) Kalliope, obtained at the 1m C2PU-Epsilon telescope on the
Plateau de Calern, France. Observations were made in the visible domain with
the speckle camera PISCO. We obtained 122 measurements in February-March 2022
and April 2023, with a mean uncertainty close to 10 milli-arcseconds on the
angular separation
Shape modeling technique KOALA validated by ESA Rosetta at (21) Lutetia
We present a comparison of our results from ground-based observations of
asteroid (21) Lutetia with imaging data acquired during the flyby of the
asteroid by the ESA Rosetta mission. This flyby provided a unique opportunity
to evaluate and calibrate our method of determination of size, 3-D shape, and
spin of an asteroid from ground-based observations. We present our 3-D
shape-modeling technique KOALA which is based on multi-dataset inversion. We
compare the results we obtained with KOALA, prior to the flyby, on asteroid
(21) Lutetia with the high-spatial resolution images of the asteroid taken with
the OSIRIS camera on-board the ESA Rosetta spacecraft, during its encounter
with Lutetia. The spin axis determined with KOALA was found to be accurate to
within two degrees, while the KOALA diameter determinations were within 2% of
the Rosetta-derived values. The 3-D shape of the KOALA model is also confirmed
by the spectacular visual agreement between both 3-D shape models (KOALA pre-
and OSIRIS post-flyby). We found a typical deviation of only 2 km at local
scales between the profiles from KOALA predictions and OSIRIS images, resulting
in a volume uncertainty provided by KOALA better than 10%. Radiometric
techniques for the interpretation of thermal infrared data also benefit greatly
from the KOALA shape model: the absolute size and geometric albedo can be
derived with high accuracy, and thermal properties, for example the thermal
inertia, can be determined unambiguously. We consider this to be a validation
of the KOALA method. Because space exploration will remain limited to only a
few objects, KOALA stands as a powerful technique to study a much larger set of
small bodies using Earth-based observations.Comment: 15 pages, 8 figures, 2 tables, accepted for publication in P&S
Inequalities in energy-balance related behaviours and family environmental determinants in European children: changes and sustainability within the EPHE evaluation study
BACKGROUND: Increasing social inequalities in health across Europe are widening the gap between low and high socio-economic groups, notably in the prevalence of obesity. Public health interventions may result in differential effects across population groups. Therefore, the EPHE (EPODE for the Promotion of Health Equity) project analysed the added value of community-based programmes, based on the EPODE (Ensemble Prévenons l'Obésité Des Enfants-Together Let's Prevent Obesity) model, to reduce socio-economic inequalities in energy balance-related behaviours of children and their family-environmental related determinants in seven European communities. This study presents the changes between baseline and follow-up after the one-year interventions and their sustainability one year after. METHODS: This is a prospective study with a one school-year intervention, followed by one year of follow-up. In all, 1266 children (age 6-8 years) and their families from different socio-economic backgrounds were recruited at baseline. For 1062 children, information was available after one year (T1) and for 921 children after two years (T2). A self-reported questionnaire was completed by the parents to examine the children's energy balance-related behaviours and family- environmental determinants. Socio-economic status was defined by the educational level of the mother. The Wilcoxon signed-rank test for paired data was used to test the differences between baseline and intermediate, and between intermediate and final, measurements for each of the socio-economic status groups. RESULTS: Post-intervention effects in energy-balance related behaviours showed the following improvements among the low socio-economic status groups: increased fruit consumption (Netherlands), decreased fruit juices amount consumed (Romania) and decreased TV time on weekdays (Belgium). Whereas in only the latter case the behavioural change was accompanied with an improvement in a family-environmental determinant (monitoring the time the child watches TV), other improvements in parental rules and practices related to soft drinks/fruit juices and TV exposure were observed. A few of those effects were sustainable, notably in the case of Belgium. CONCLUSIONS: Inequalities in obesity-related behaviours could be potentially reduced when implementing community-based interventions, tailored to inequality gaps and using the EPODE methodology. Within-group changes varied widely, whereas monitoring of interventions and process evaluation are crucial to understand the observed results
(16) Psyche: A mesosiderite-like asteroid?
Asteroid (16) Psyche is the target of the NASA Psyche mission. It is
considered one of the few main-belt bodies that could be an exposed
proto-planetary metallic core and that would thus be related to iron
meteorites. Such an association is however challenged by both its near- and
mid-infrared spectral properties and the reported estimates of its density.
Here, we aim to refine the density of (16) Psyche to set further constraints on
its bulk composition and determine its potential meteoritic analog.
We observed (16) Psyche with ESO VLT/SPHERE/ZIMPOL as part of our large
program (ID 199.C-0074). We used the high angular resolution of these
observations to refine Psyche's three-dimensional (3D) shape model and
subsequently its density when combined with the most recent mass estimates. In
addition, we searched for potential companions around the asteroid. We derived
a bulk density of 3.99\,\,0.26\,gcm for Psyche. While such
density is incompatible at the 3-sigma level with any iron meteorites
(7.8\,gcm), it appears fully consistent with that of
stony-iron meteorites such as mesosiderites (density
4.25\,cm). In addition, we found no satellite in our images
and set an upper limit on the diameter of any non-detected satellite of
1460\,\,200}\,m at 150\,km from Psyche (0.2\%\,\,R, the
Hill radius) and 800\,\,200\,m at 2,000\,km (3\%\,\,).
Considering that the visible and near-infrared spectral properties of
mesosiderites are similar to those of Psyche, there is merit to a
long-published initial hypothesis that Psyche could be a plausible candidate
parent body for mesosiderites.Comment: 16 page
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