2,104 research outputs found
A Malaria Ecology Index Predicted Spatial and Temporal Variation of Malaria Burden and Efficacy of Antimalarial Interventions Based on African Serological Data.
Reducing the global health burden of malaria is complicated by weak reporting systems for infectious diseases and a paucity of vital statistics registration. This limits our ability to predict changes in malaria health burden intensity, target antimalarial resources where needed, and identify malaria impacts in retrospective data. We refined and deployed a temporally and spatially varying Malaria Ecology Index (MEI) incorporating climatological and ecological data to estimate malaria transmission strength and validate it against cross-sectional serology data from 39,875 children from seven sub-Saharan African countries. The MEI is strongly associated with malaria burden; a 1 standard deviation higher MEI is associated with a 50-117% increase in malaria risk and a 3-5 g/dL lower level of Hg. Results show that the relationship between malaria ecology and disease burden is attenuated with sufficient coverage of insecticide treated nets (ITNs) or indoor residual spraying (IRS). Having both ITNs and IRS reduce the added risk from adverse malaria ecology conditions by half. Readily available climate and ecology data can be used to estimate the spatial and temporal variation in malaria disease burden, providing a feasible alternative to direct surveillance. This will help target resources for malaria programs in the absence of national coverage of active case detection systems, and facilitate malaria research using retrospective health data
A REVIEW OF CHALLENGES IN ASSESSMENT AND FORECASTING OF WIND ENERGY RESOURCES
The main issues related to assessment and forecasting of the wind and wind energy have been reviewed. These include the limitations and advantages of wind forecasting and assessment of the wind power density, especially considering trends of increasing penetration of wind-generated power into the utility grid and storage of wind-generated power. Accurate forecasting of the wind power density over a large range of spatial and temporal scales is a critical
issue for planning and operations of wind farms. A review of various prediction tools, from simple statistical models to highly complex numerical techniques, was performed for this purpose. The influence of wind variability, atmospheric stability, turbulence, and the low-level jets on wind power density are elaborated on in detail. Furthermore, prediction and assessment of future wind energy resources and their economic implications as well as environmental concerns such as birdsâ habitats and routes, viewpoint aesthetics, and noise are also discussed in this study. Some climate projection studies indicate minor changes in the wind resources comparable
to differences in global models results while others argue that the wind resources will be reduced due to global warming and they call for harvesting wind energy at the maximum rate as soon as possible
Looking Back, Looking Forward: How the Economic Downturn Continues to Impact School Districts
This study is the fourth in a series of studies conducted by the American Association of School Administrators on the impact of the economic downturn on schools.
Collectively, the findings of the AASA Economic Impact Study series demonstrate that school districts in every part of the country are subject to the realities of the economic downturn. While this benchmark data cannot predict a trend, it is difficult to deny that the financial crisis is increasingly threatening the progress schools have obtained and the stability they have enjoyed in the past.
This latest study, âLooking Back, Looking Forward: How the Economic Downturn Continues to Impact School Districts,â is based on a study of school administrators conducted in February and March 2009. This survey asked many of the same questions as the âAASA Study of the Impact of the Economic Downturn on Schools,â conducted in October 2008. Therefore, it is possible to compare and contrast key findings from the two studies
Impact of the Economic Downturn on Schools
In Fall 2008, in response to the recent economic downturn, as evidenced in state budget shortfalls, federal buyâouts and interventions, and a series of additional events characterizing a slowing, stagnant economy, AASA examined the impact on school districts across the nation. While there are regional differences, the findings of AASAâs Economic Impact Survey, presented here, demonstrate that superintendents in every part of the country are subject to the realities of the economic downturn. While this benchmark data cannot predict a trend, it is difficult to deny that superintendents, in increasing numbers, are confronted by the looming financial crisis that threatens the progress schools have obtained and the stability they have enjoyed in the past
The impact of training non-physician clinicians in Malawi on maternal and perinatal mortality : a cluster randomised controlled evaluation of the enhancing training and appropriate technologies for mothers and babies in Africa (ETATMBA) project
Background:
Maternal mortality in much of sub-Saharan Africa is very high whereas there has been a steady decline in over the past 60 years in Europe. Perinatal mortality is 12 times higher than maternal mortality accounting for about 7 million neonatal deaths; many of these in sub-Saharan countries. Many of these deaths are preventable. Countries, like Malawi, do not have the resources nor highly trained medical specialists using complex technologies within their healthcare system. Much of the burden falls on healthcare staff other than doctors including non-physician clinicians (NPCs) such as clinical officers, midwives and community health-workers. The aim of this trial is to evaluate a project which is training NPCs as advanced leaders by providing them with skills and knowledge in advanced neonatal and obstetric care. Training that will hopefully be cascaded to their colleagues (other NPCs, midwives, nurses).
Methods/design:
This is a cluster randomised controlled trial with the unit of randomisation being the 14 districts of central and northern Malawi (one large district was divided into two giving an overall total of 15). Eight districts will be randomly allocated the intervention. Within these eight districts 50 NPCs will be selected and will be enrolled on the training programme (the intervention). Primary outcome will be maternal and perinatal (defined as until discharge from health facility) mortality. Data will be harvested from all facilities in both intervention and control districts for the lifetime of the project (3â4 years) and comparisons made. In addition a process evaluation using both quantitative and qualitative (e.g. interviews) will be undertaken to evaluate the intervention implementation.
Discussion:
Education and training of NPCs is a key to improving healthcare for mothers and babies in countries like Malawi. Some of the challenges faced are discussed as are the potential limitations. It is hoped that the findings from this trial will lead to a sustainable improvement in healthcare and workforce development and training.
Trial registration:
ISRCTN6329415
Self-similarity and novel sample-length-dependence of conductance in quasiperiodic lateral magnetic superlattices
We study the transport of electrons in a Fibonacci magnetic superlattice
produced on a two-dimensional electron gas modulated by parallel magnetic field
stripes arranged in a Fibonacci sequence. Both the transmission coefficient and
conductance exhibit self-similarity and the six-circle property. The presence
of extended states yields a finite conductivity at infinite length, that may be
detected as an abrupt change in the conductance as the Fermi energy is varied,
much as a metal-insulator transition. This is a unique feature of transport in
this new kind of structure, arising from its inherent two-dimensional nature.Comment: 9 pages, 5 figures, revtex, important revisions made. to be published
in Phys. Rev.
The SOS Pilot Study: a RCT of routine oxygen supplementation early after acute strokeâeffect on recovery of neurological function at one week
Mild hypoxia is common after stroke and associated with poor long-term outcome. Oxygen supplementation could prevent hypoxia and improve recovery. A previous study of routine oxygen supplementation showed no significant benefit at 7 and 12 months. This pilot study reports the effects of routine oxygen supplementation for 72 hours on oxygen saturation and neurological outcomes at 1 week after a stroke
Cassini/VIMS hyperspectral observations of the HUYGENS landing site on Titan
Titan is one of the primary scientific objectives of the NASA ESA ASI Cassini
Huygens mission. Scattering by haze particles in Titan's atmosphere and
numerous methane absorptions dramatically veil Titan's surface in the visible
range, though it can be studied more easily in some narrow infrared windows.
The Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the
Cassini spacecraft successfully imaged its surface in the atmospheric windows,
taking hyperspectral images in the range 0.4 5.2 ?m. On 26 October (TA flyby)
and 13 December 2004 (TB flyby), the Cassini Huygens mission flew over Titan at
an altitude lower than 1200 km at closest approach. We report here on the
analysis of VIMS images of the Huygens landing site acquired at TA and TB, with
a spatial resolution ranging from 16 to14.4 km/pixel. The pure atmospheric
backscattering component is corrected by using both an empirical method and a
first-order theoretical model. Both approaches provide consistent results.
After the removal of scattering, ratio images reveal subtle surface
heterogeneities. A particularly contrasted structure appears in ratio images
involving the 1.59 and 2.03 ?m images north of the Huygens landing site.
Although pure water ice cannot be the only component exposed at Titan's
surface, this area is consistent with a local enrichment in exposed water ice
and seems to be consistent with DISR/Huygens images and spectra
interpretations. The images show also a morphological structure that can be
interpreted as a 150 km diameter impact crater with a central peak
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SIMPLE TRANSIENT CALCULATIONS OF CELL FLAMMABLE GAS CONCENTRATIONS
The Saltstone Facility at Savannah River Site (SRS) mixes low-level radiological liquid waste with grout for permanent disposal as cement in vault cells. The grout mixture is poured into each cell in approximately 17 batches (8 to 10 hours duration). The grout mixture contains ten flammable gases of concern that are released from the mixture into the cell. Prior to operations, simple parametric transient calculations were performed to develop batch parameters (including schedule of batch pours) to support operational efficiency while ensuring that a flammable gas mixture does not develop in the cell vapor space. The analysis demonstrated that a nonflammable vapor space environment can be achieved, with workable operational constraints, without crediting the ventilation flow as a safety system control. Isopar L was identified as the primary flammable gas of concern. The transient calculations balanced inflows of the flammable gases into the vapor space with credited outflows of diurnal breathing through vent holes and displacement from new grout pours and gases generated. Other important features of the analyses included identifying conditions that inhibited a well-mixed vapor space, the expected frequency and duration of such conditions, and the estimated level of stratification that could develop
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