270 research outputs found
Novel Single Photon Detectors for UV Imaging
There are several applications which require high position resolution UV
imaging. For these applications we have developed and successfully tested a new
version of a 2D UV single photon imaging detector based on a microgap RPC. The
main features of such a detectors is the high position resolution - 30 micron
in digital form and the high quantum efficiency (1-8% in the spectral interval
of 220-140 nm). Additionally, they are spark- protected and can operate without
any feedback problems at high gains, close to a streamer mode. In attempts to
extend the sensitivity of RPCs to longer wavelengths we have successfully
tested the operation of the first sealed parallel-plate gaseous detectors with
CsTe photocathodes. Finally, the comparison with other types of photosensitive
detectors is given and possible fields of applications are identified.Comment: Presented at the 5th International Workshop on RICH detectors Playa
del Carmen, Mexico, November 200
Perception and practice of Kangaroo Mother Care after discharge from hospital in Kumasi, Ghana: A longitudinal study
BACKGROUND: The practice of Kangaroo Mother Care (KMC) is life saving in babies weighing less than 2000 g. Little is known about mothers' continued unsupervised practice after discharge from hospitals. This study aimed to evaluate its in-hospital and continued practice in the community among mothers of low birth weight (LBW) infants discharged from two hospitals in Kumasi, Ghana. METHODS: A longitudinal study of 202 mothers and their inpatient LBW neonates was conducted from November 2009 to May 2010. Mothers were interviewed at recruitment to ascertain their knowledge of KMC, and then oriented on its practice. After discharge, the mothers reported at weekly intervals for four follow up visits where data about their perceptions, attitudes and practices of KMC were recorded. A repeated measure logistic regression analysis was done to assess variability in the binary responses at the various reviews visits. RESULTS: At recruitment 23 (11.4%, 95%CI: 7.4 to 16.6%) mothers knew about KMC. At discharge 95.5% were willing to continue KMC at home with 93.1% willing to practice at night. 95.5% thought KMC was beneficial to them and 96.0% beneficial to their babies. 98.0% would recommend KMC to other mothers with 71.8% willing to practice KMC outdoors.At first follow up visit 99.5% (181) were still practicing either intermittent or continuous KMC. This proportion did not change significantly over the four weeks (OR: 1.4, 95%CI: 0.6 to 3.3, p-value: 0.333). Over the four weeks, increasingly more mothers practiced KMC at night (OR: 1.7, 95%CI: 1.2 to 2.6, p = 0.005), outside their homes (OR: 2.4, 95%CI: 1.7 to 3.3, p < 0.001) and received spousal help (OR: 1.6, 95%CI: 1.1 to 2.4, p = 0.007). Household chores and potentially negative community perceptions of KMC did not affect its practice with odds of 0.8 (95%CI: 0.5 to 1.2, p = 0.282) and 1.0 (95%CI: 0.6 to 1.7, p = 0.934) respectively. During the follow-up period the neonates gained 23.7 sg (95%CI: 22.6 g to 24.7 g) per day. CONCLUSION: Maternal knowledge of KMC was low at outset. Once initiated mothers continued practicing KMC in hospital and at home with their infants gaining optimal weight. Continued KMC practice was not affected by perceived community attitudes
Determining the azimuthal properties of coronal mass ejections from multi-spacecraft remote-sensing observations with stereo secchi
We discuss how simultaneous observations by multiple heliospheric imagers can
provide some important information about the azimuthal properties of Coronal
Mass Ejections (CMEs) in the heliosphere. We propose two simple models of CME
geometry that can be used to derive information about the azimuthal deflection
and the azimuthal expansion of CMEs from SECCHI/HI observations. We apply these
two models to four CMEs well-observed by both STEREO spacecraft during the year
2008. We find that in three cases, the joint STEREO-A and B observations are
consistent with CMEs moving radially outward. In some cases, we are able to
derive the azimuthal cross-section of the CME fronts, and we are able to
measure the deviation from self-similar evolution. The results from this
analysis show the importance of having multiple satellites dedicated to space
weather forecasting, for example in orbits at the Lagrangian L4 and L5 points.Comment: 7 pages, 4 figures, 1 table, accepted to Ap
Report on an international workshop on kangaroo mother care: lessons learned and a vision for the future.
Globally, complications of prematurity are the leading cause of death in children under five. Preterm infants who survive their first month of life are at greater risk for various diseases and impairments in infancy, childhood and later life, representing a heavy social and economic burden for families, communities and health and social systems. Kangaroo mother care (KMC) is recommended as a beneficial and effective intervention for improving short- and long-term preterm birth outcomes in low- and high-income settings. Nevertheless, KMC is not as widely used as it should be. The International Network on KMC runs biennial workshops and congresses to help improve the coverage and quality of KMC worldwide. This paper reports the results of the two-day workshop held in November 2016, where 92 participants from 33 countries shared experiences in a series of round tables, group work sessions and plenaries.
Barriers to and enablers of KMC are discussed with regard to parents, health workers and the health system. Key factors for effective implementation and uptake relate to appropriate training for health staff, adherence to protocols and the creation of a welcoming environment for families. Recommendations for planning for national programmes are made according to a six-stage change model. Resources and the cost of making progress are discussed in terms of investment, maintenance, and acceleration and scaling-up costs. KMC training requirements are presented according to three levels of care. To ensure quality KMC, key requisites are proposed for the different KMC components and for sensitive communication with caregivers. The group attending to the monitoring and evaluation of KMC at a national and subnational level highlight the lack of standard indicator definitions. Key priorities for investment include health services research, harmonisation of indicators, development of a costing tool, programming and scaling up, and the follow-up of preterm infants.
It is hoped that this report will help to further scale-up and sustain KMC through a systematic approach that includes raising commitment, identifying key strategies to address the main barriers and using existing facilitators, ensuring training and quality, agreeing on indicators for monitoring and evaluation, and advancing implementation research
A new regime of nanoscale thermal transport: collective diffusion counteracts dissipation inefficiency
Understanding thermal transport from nanoscale heat sources is important for
a fundamental description of energy flow in materials, as well as for many
technological applications including thermal management in nanoelectronics,
thermoelectric devices, nano-enhanced photovoltaics and nanoparticle-mediated
thermal therapies. Thermal transport at the nanoscale is fundamentally
different from that at the macroscale and is determined by the distribution of
carrier mean free paths in a material, the length scales of the heat sources,
and the distance over which heat is transported. Past work has shown that
Fourier's law for heat conduction dramatically over-predicts the rate of heat
dissipation from heat sources with dimensions smaller than the mean free path
of the dominant heat-carrying phonons. In this work, we uncover a new regime of
nanoscale thermal transport that dominates when the separation between
nanoscale heat sources is small compared with the dominant phonon mean free
paths. Surprisingly, the interplay between neighboring heat sources can
facilitate efficient, diffusive-like heat dissipation, even from the smallest
nanoscale heat sources. This finding suggests that thermal management in
nanoscale systems including integrated circuits might not be as challenging as
projected. Finally, we demonstrate a unique and new capability to extract mean
free path distributions of phonons in materials, allowing the first
experimental validation of differential conductivity predictions from
first-principles calculations.Comment: Main text: 18 pages, 4 figures. Supplementary Information: 13 pages,
9 figure
Position Reconstruction in Drift Chambers operated with Xe, CO2 (15%)
We present measurements of position and angular resolution of drift chambers
operated with a Xe,CO(15%) mixture. The results are compared to Monte Carlo
simulations and important systematic effects, in particular the dispersive
nature of the absorption of transition radiation and non-linearities, are
discussed. The measurements were carried out with prototype drift chambers of
the ALICE Transition Radiation Detector, but our findings can be generalized to
other drift chambers with similar geometry, where the electron drift is
perpendicular to the wire planes.Comment: 30 pages, 18 figure
Charge amplification concepts for direction-sensitive dark matter detectors
Direction measurement of weakly interacting massive particles in
time-projection chambers can provide definite evidence of their existence and
help to determine their properties. This article demonstrates several concepts
for charge amplification in time-projection chambers that can be used in
direction-sensitive dark matter search experiments. We demonstrate
reconstruction of the 'head-tail' effect for nuclear recoils above 100keV, and
discuss the detector performance in the context of dark matter detection and
scaling to large detector volumes.Comment: 15 pages, 9 figure
Kangaroo Mother Care, home environment and father involvement in the first year of life : a randomized controlled study
Q2Q11444-1450AIMS:
This study tested the hypothesis that Kangaroo Mother Care creates a climate in the family, which enhances infants' performance on the developmental quotient scale.
SETTING:
The largest social security hospital in Colombia with a neonatal intensive care unit.
SUBJECTS:
At 12 months of corrected age, 194 families in the Kangaroo Mother Care group and 144 families in the Traditional Care group were available for analysis.
INTERVENTIONS:
Infants were kept 24 h/day in an upright position, in skin-to-skin contact until it was no longer tolerated by the infants. Babies in the Traditional Care were kept in incubators on the Minimal Care Unit until they satisfied the usual discharge criteria.
OUTCOME MEASURES:
The Home Observation for Measurement of the Environment (HOME), Father Involvement and Developmental Quotient (Griffiths) scores.
RESULTS:
1) Kangaroo mothers created a more stimulating context and a better caregiving environment than mothers in the Traditional Care group; 2) this environment was positively correlated to father involvement and 3) the family environment of male infants was most improved by Kangaroo Mother Care.
CONCLUSION:
Kangaroo Mother Care has a positive impact on home environment. The results also suggest, first, that both parents should be involved as direct caregivers in the Kangaroo Mother Care procedure and secondly, that this intervention should be directed more specifically at infants who are more at risk at birth. The Kangaroo Mother Care intervention could be an excellent means to ensure parents' mature involvement in the future of their children
Recommended from our members
A General and Predictive Understanding of Thermal Transport from 1D- and 2D-Confined Nanostructures : Theory and Experiment
Altres ajuts: Acord transformatiu CRUE-CSICHeat management is crucial in the design of nanoscale devices as the operating temperature determines their efficiency and lifetime. Past experimental and theoretical works exploring nanoscale heat transport in semiconductors addressed known deviations from Fourier's law modeling by including effective parameters, such as a size-dependent thermal conductivity. However, recent experiments have qualitatively shown behavior that cannot be modeled in this way. Here, we combine advanced experiment and theory to show that the cooling of 1D- and 2D-confined nanoscale hot spots on silicon can be described using a general hydrodynamic heat transport model, contrary to previous understanding of heat flow in bulk silicon. We use a comprehensive set of extreme ultraviolet scatterometry measurements of nondiffusive transport from transiently heated nanolines and nanodots to validate and generalize our ab initio model, that does not need any geometry-dependent fitting parameters. This allows us to uncover the existence of two distinct time scales and heat transport mechanisms: an interface resistance regime that dominates on short time scales and a hydrodynamic-like phonon transport regime that dominates on longer time scales. Moreover, our model can predict the full thermomechanical response on nanometer length scales and picosecond time scales for arbitrary geometries, providing an advanced practical tool for thermal management of nanoscale technologies. Furthermore, we derive analytical expressions for the transport time scales, valid for a subset of geometries, supplying a route for optimizing heat dissipation
- …