7,625 research outputs found
The Costs of Low Birth Weight
Birth weight has emerged as the leading indicator of infant health and welfare and the central focus of infant health policy. This is because low birth weight (LBW) infants experience severe health and developmental difficulties that can impose enormous costs on society. But would the prevention of LBW generate equally sizable cost savings and health improvements? Estimates of the return to LBW-prevention from cross-sectional associations may be biased by omitted variables that cannot be influenced by policy, such as genetic factors. To address this, we compare the hospital costs, health at birth, and infant mortality rates between heavier and lighter infants from all twin pairs born in the United States. We also examine the effect of maternal smoking during pregnancy the leading risk factor for LBW in the United States on health among singleton births after controlling for detailed background characteristics. Both analyses imply substantially smaller effects of LBW than previously thought, suggesting two possibilities: 1) existing estimates overstate the true costs and consequences of LBW by at least a factor of four and by as much as a factor of 20; or 2) different LBW-preventing interventions have different health and cost consequences, implying that policy efforts that presume a single return to reducing LBW will necessarily be suboptimal.
An Approximation Method of Calculating the Present Worth of Nonintegrable Cash Flow Patterns
An approximation method is provided for calculating the present worth of nonintegrable continuous cash flows that have common industrial economic applications. Two limiting cases of particular use in engineering screening analyses are given for each model. Practical examples are presented to illustrate the application of the cash flow models to manpower reductions due to computerized process control and to cash flows for a pollution-abatement facility
Assessing the fugitive emission of CH4 via migration along fault zones – Comparing potential shale gas basins to non-shale basins in the UK
This study considered whether faults bounding hydrocarbon-bearing basins could be conduits for methane release to the atmosphere. Five basin bounding faults in the UK were considered: two which bounded potential shale gas basins; two faults that bounded coal basins; and one that bounded a basin with no known hydrocarbon deposits. In each basin, two mobile methane surveys were conducted, one along the surface expression of the basin bounding fault and one along a line of similar length but not intersecting the fault. All survey data was corrected for wind direction, the ambient CH4 concentration and the distance to the possible source. The survey design allowed for Analysis of Variance and this showed that there was a significant difference between the fault and control survey lines though a significant flux from the fault was not found in all basins and there was no apparent link to the presence, or absence, of hydrocarbons. As such, shale basins did not have a significantly different CH4 flux to non-shale hydrocarbon basins and non-hydrocarbon basins. These results could have implications for CH4 emissions from faults both in the UK and globally. Including all the corrected fault data, we estimate faults have an emissions factor of 11.5 ± 6.3 t CH4/km/yr, while the most conservative estimate of the flux from faults is 0.7 ± 0.3 t CH4/km/yr. The use of isotopes meant that at least one site of thermogenic flux from a fault could be identified. However, the total length of faults that penetrate through-basins and go from the surface to hydrocarbon reservoirs at depth in the UK is not known; as such, the emissions factor could not be multiplied by an activity level to estimate a total UK CH4 flux
Recommended from our members
Multi-scale analysis and validation of the Envisat MERIS Terrestrial Chlorophyll Index (MTCI) in woodland
Satellite remote sensing can be used to estimate and monitor the chlorophyll content of vegetation canopies which are a key and dynamic component of global terrestrial ecosystems. The red-edge algorithm can be used to estimate chlorophyll content from remotely sensed data but is unsuitable for use with most satellite sensor imagery. To overcome this problem, the new Envisat MERIS Terrestrial Chlorophyll index (MTCI) has been developed. It is the only operational satellite chlorophyll index and MTCI data are available as a Level 2 product from the European Space Agency. However, there is a need to ‘validate’ the MTCI over a wide range of environmental conditions. This paper reports on research that attempts to validate the MTCI using Compact Airborne Spectrographic Imager (CASI) imagery and ground data of chlorophyll content. The study site was predominantly woodland in the south of England (New Forest National Park) and had a wide range of chlorophyll contents. A transfer function derived from CASI data was used to produce a reference map of chlorophyll content, when aggregated it was compared to MERIS MTCI data and used to derive the MTCI – chlorophyll content relationship (R squared = 0.56)
The challenges of renal replacement therapy and renal palliative care in the elderly
Much of the increase in take on rate for dialysis in recent years is accounted for by older patients in whom a treatment as demanding as dialysis was previously thought to be contraindicated. The decision to dialyse the elderly often remains difficult, as recent data suggest that those with significant comorbidities are unlikely to survive more than 4-6 months longer on dialysis than they would have done if treated conservatively. It is also important to recognise that conservative treatment is not simply defined by the decision not to dialyse. Good conservative care comprises active disease management eg treatment of anaemia with erythropoietin stimulating agents and intravenous iron, and supportive care which may become increasingly complex eg pain relief with fentanyl and alfentanyl, towards the end of life. Those older patients who do decide to dialyse must contend with all the usual end of life issues facing older people, in addition to the option, denied to the rest of us, of dialysis withdrawal which effectively allows them to die at a time of their choosing
Youngest dinocephalian fossils extend the Tapinocephalus Zone, Karoo Basin, South Africa.
The dinocephalians (Synapsida, Therapsida) were one of the dominant tetrapod groups of the Middle Permian (Guadalupian Epoch, ∼270-260 million years ago) and are most abundantly recorded in the Tapinocephalus Assemblage Zone (AZ) of the Main Karoo Basin, South Africa. Dinocephalians are thought to have become extinct near the top of the Abrahamskraal Formation of the Beaufort Group and their disappearance is one criterion used to define the base of the overlying Pristerognathus AZ. Because of the abundance of fossils in the Karoo, the Beaufort Group biozones form the biostratigraphic standard for later Permian terrestrial tetrapod ecosystems, so their stratigraphic delineation is of great importance to Permian palaeobiology. We report two new specimens of the rare tapinocephalid dinocephalian Criocephalosaurus from the lowermost Poortjie Member, which makes them the youngest dinocephalians known from the Main Karoo Basin and extends the Tapinocephalus AZ from the Abrahamskraal Formation up into the Teekloof Formation. The extension of the Tapinocephalus AZ relative to the lithostratigraphy potentially affects the biozone or biozones to which a fossil species can be attributed; this extension has implications for biostratigraphic correlations within the Main Karoo Basin as well as with other basins across Gondwana. These discoveries also indicate that a population of herbivorous tapinocephalids survived as rare constituents of the tetrapod fauna after most generic richness within the clade had already been lost.NCS201
NUCLEIC-ACID BINDING-DRUGS .8. STRUCTURES OF 1-[2-(DIETHYLAMINO)ETHYLAMINO]ANTHRACENE-9,10-DIONE, C20H22N2O2 (I), AND 1,5-BIS[2-(DIETHYLAMINO)ETHYLAMINO]ANTHRACENE-9,10-DIONE, C26H36N4O2(II), MODELS FOR ANTI-TUMOR DRUGS
(I) M r = 322.41, P21/n, a = 7.118 (1), b = 26.873(2), c=8.886(1)A, fl=97.74(1)°, ~ V= 1684.3 (6) A 3, Z = 4, D m = 1.27, D x = 1.271 Mg m -3, 2 (Cu Ka) = 1.54178 A,/~ = 6.67 cm -1, F(000) = 688, T= 298 K, R w= 0.049 for 981 unique significant reflections. (II) Mr=436.61, P21/c, a= 15.360 (2), b = 5.245 (1), c= 15.483 (1)A, fl= 94.23 (1) °, V= 1244.0 (5)/~3, Z = 2, D m -- 1.17, D x = 1.165 Mg m -s, 2(Cu Kt~) = 1.54178/k, /t = 5.98 cm -1, F(000) = 472, T= 298 K, R w = 0.090 for 457 unique significant reflections. The chromophore is highly planar in both compounds
Recommended from our members
Phenological trends of vegetation in Southern England From Envisat MERIS Terrestrial Chlorophyll Index (MTCI) data
Given the close association between climate change and vegetation response there is a pressing requirement to monitor the phenology of vegetation and understand how its metrics vary over space and time. This paper explores the viability of the Envisat MTCI dataset for monitoring vegetation phenology via its estimates of chlorophyll content. The MTCI was used to construct the phenological profile of and to extract key phenological dates from mixed woodland in Southern England. Woodland phenological cycles for the time period 2003 to 2007, a period with known temperature anomalies forcing variability in the phenology of the vegetation, were derived from MERIS MTCI data. Comparisons were made with ground indicators of phenology, and furthermore, crosscomparisons with other vegetation indices, namely the NDVI and EVI derived from MODIS data were conducted. Close correspondence between MTCI and canopy phenology as indicated by ground observations was evident. Also observed was a difference between MTCI-derived phenological transition curves and key transition dates and those derived from the NDVI and EVI. Overall the research presented in this paper supports the use of the Envisat MTCI for monitoring vegetation phenology, principally due to its sensitivity to canopy chlorophyll content, a vegetation property that is a useful proxy for the canopy physical and chemical alterations associated with phenological change
- …