1,027 research outputs found
Recommended from our members
Privatisation Methods and Economic Growth in Transition Economies
In low-income countries privatization, if implemented appropriately, may play an
important role in generating growth. Using data recently available from Central and
Eastern Europe, we therefore investigate the impact of alternative methods of
privatization on economic growth. Our analysis suggests that the use of conventional
privatization methods to match owners with firms can be inefficient in economies
with underdeveloped capital markets, particularly if wealth is poorly correlated with
managerial and entrepreneurial ability. In these circumstances mass privatization,
with firms being given away or sold at a nominal price, may be the appropriate policy
choice
Exploration into technical procedures for vertical integration
Issues in the design and use of a digital geographic information system incorporating landuse, zoning, hazard, LANDSAT, and other data are discussed. An eleven layer database was generated. Issues in spatial resolution, registration, grid versus polygonal structures, and comparison of photointerpreted landuse to LANDSAT land cover are examined
Annotated Bibliography of the Center for Urban Affairs Data Bank/Information Center
The Center for Urban Affairs maintains a Data Bank/Information Center, consisting of urban-related periodicals, newspaper clippings, bibliographies, and documents.
In an effort to familiarize users with the contents of the Data Bank, the CUA has compiled an annotated bibliography, which will be periodically updated to include new materials. Many of the documents listed are available on loan to Data Bank users. Other documents which cannot be loaned, are available for use in the Center, or pages of interest may be Xeroxed
Gates to Gregg High Voltage Transmission Line Study
The usefulness of LANDSAT data in the planning of transmission line routes was assessed. LANDSAT digital data and image processing techniques, specifically a multi-date supervised classification aproach, were used to develop a land cover map for an agricultural area near Fresno, California. Twenty-six land cover classes were identified, of which twenty classes were agricultural crops. High classification accuracies (greater than 80%) were attained for several classes, including cotton, grain, and vineyards. The primary products generated were 1:24,000, 1:100,000 and 1:250,000 scale maps of the classification and acreage summaries for all land cover classes within four alternate transmission line routes
Preventing human immunodeficiency virus infection among sexual assault survivors in Cape Town, South Africa: an observational study.
We describe 131 South African sexual assault survivors offered HIV post-exposure prophylaxis (PEP). While the median days completed was 27 (IQR 27, 28), 34% stopped PEP or missed doses. Controlling for baseline symptoms, PEP was not associated with symptoms (OR = 1.30, 95% CI = 0.66, 2.64). Factors associated with unprotected sex included prior unprotected sex (OR = 6.46, 95% CI = 3.04, 13.74), time since the assault (OR = 1.33, 95% CI = 1.12, 1.57) and age (OR = 1.30, 95% CI = 1.08, 1.57). Trauma counseling was protective (OR = 0.18, 95% CI = 0.05, 0.58). Four instances of seroconversion were observed by 6 months (risk = 3.7%, 95% CI = 1.0, 9.1). Proactive follow-up is necessary to increase the likelihood of PEP completion and address the mental health and HIV risk needs of survivors. Adherence interventions and targeted risk reduction counseling should be provided to minimize HIV acquisition
Charge-ordering, commensurability and metallicity in the phase diagram of layered Na(x)CoO(2)
The phase diagram of non-hydrated Na(x)CoO(2) has been determined by changing
the Na content x using a series of chemical reactions. As x increases from 0.3,
the ground state goes from a paramagnetic metal to a charge-ordered insulator
(at x=1/2) to a `Curie-Weiss metal' (around 0.70), and finally to a weak-moment
magnetically ordered state (x>0.75). The unusual properties of the state at 1/2
(including particle-hole symmetry at low T and enhanced thermal conductivity)
are described. The strong coupling between the Na ions and the holes is
emphasized.Comment: 4 pages with 3 figures, changed conten
Plate-impact loading of cellular structures formed by selective laser melting
Porous materials are of great interest because of improved energy absorption over their solid counterparts. Their properties, however, have been difficult to optimize. Additive manufacturing has emerged as a potential technique to closely define the structure and properties of porous components, i.e. density, strut width and pore size; however, the behaviour of these materials at very high impact energies remains largely unexplored. We describe an initial study of the dynamic compression response of lattice materials fabricated through additive manufacturing. Lattices consisting of an array of intersecting stainless steel rods were fabricated into discs using selective laser melting. The resulting discs were impacted against solid stainless steel targets at velocities ranging from 300 to 700 m s-1 using a gas gun. Continuum CTH simulations were performed to identify key features in the measured wave profiles, while 3D simulations, in which the individual cells were modelled, revealed details of microscale deformation during collapse of the lattice structure. The validated computer models have been used to provide an understanding of the deformation processes in the cellular samples. The study supports the optimization of cellular structures for application as energy absorbers. © 2014 IOP Publishing Ltd
Influence of Hospital Volume on Nephrectomy Mortality and Complications: A Systematic Review and Meta-analysis Stratified by Surgical Type
Objectives
The provision of complex surgery is increasingly centralised to high volume specialist hospitals. Evidence to support nephrectomy centralisation however has been inconsistent. We conducted a systematic review and meta-analysis to determine the association between hospital case volumes and perioperative outcomes in radical nephrectomy, partial nephrectomy and nephrectomy with venous thrombectomy.
Methods
Medline, Embase and the Cochrane Library were searched for relevant studies published between 1990 and 2016. Pooled effect estimates for nephrectomy mortality and complications were calculated for each nephrectomy type using the DerSimonian and Laird random-effects model. Sensitivity analyses were performed to examine the effects of heterogeneity on the pooled effect estimates by excluding studies with the heaviest weighting, lowest methodological score, and most likely to introduce bias from misclassification of standardised hospital volume.
Results
Some 226,372 patients from sixteen publications were included in our review and meta-analysis. Considerable between-study heterogeneity was noted and only a few reported volume-outcome relationships specifically in partial nephrectomy or nephrectomy with venous thrombectomy.
High volume hospitals were correlated with a 26% and 52% reduction in mortality for radical nephrectomy (OR 0.74, 95% CI 0.61-0.90, p<0.01) and nephrectomy with venous thrombectomy (OR 0.48, 95% CI 0.29-0.81, p<0.01) respectively. In addition, radical nephrectomy in high volume hospitals was associated with an 18% reduction in complications (OR 0.82, 95% CI 0.73-0.92, p<0.01). No significant volume-outcome relationship in mortality (OR 0.84, 95% CI 0.31-2.26, p=0.73) or complications (OR 0.85, 95% CI 0.55-1.30, p=0.44) was observed for partial nephrectomy.
Conclusions
Our findings suggest that patients undergoing radical nephrectomy have improved outcomes when treated by high volume hospitals. Evidence of this in partial nephrectomy and nephrectomy with venous thrombectomy is however not yet clear and could be secondary to the low number of studies included and the small patient number in our analyses. Further investigation is warranted to establish the full potential of nephrectomy centralisation particularly as existing evidence is of low quality with significant heterogeneity.This work was supported by Addenbrooke’s Charitable Trust, the Royal College of Surgeons of England and the Urology Foundation. Cancer Research UK Advanced Clinician Scientist Fellowship award (No. C18081/A18180) has supported GL and TS
First-order magnetic and structural phase transitions in FeSeTe
We use bulk magnetic susceptibility, electronic specific heat, and neutron
scattering to study structural and magnetic phase transitions in FeSe%
Te. FeTe exhibits a first order phase transition near 67
K with a tetragonal to monoclinic structural transition and simultaneously
develops a collinear antiferromagnetic (AF) order responsible for the entropy
change across the transition. Systematic studies of FeSeTe system
reveal that the AF structure and lattice distortion in these materials are
different from those of FeAs-based pnictides. These results call into question
the conclusions of present density functional calculations, where
FeSeTe and FeAs-based pnictides are expected to have similar Fermi
surfaces and therefore the same spin-density-wave AF order.Comment: 5 pages, 3 figure
- …