252 research outputs found
Coupled magnetic and elastic properties in LaPr(CaSr)MnO manganites
We investigate a series of manganese oxides, the
La0.225Pr0.4(Ca1-xSrx)0.375MnO3 system. The x = 0 sample is a prototype
compound for the study of phase separation in manganites, where ferromagnetic
and charge ordered antiferromagnetic phases coexist. Replacing Ca2+ by Sr2+
gradually turns the system into a homogeneous ferromagnet. Our results show
that the material structure plays a major role in the observed magnetic
properties. On cooling, at temperatures below 100 K, a strong contraction of
the lattice is followed by an increase in the magnetization. This is observed
both through thermal expansion and magnetostriction measurements, providing
distinct evidence of magneto-elastic coupling in these phase separated
compounds
Misallocation and Productivity in Colombia’S Manufacturing Industries
Following Hsieh and Klenow (2009), this paper studies productivity dispersions in Colombian industrial establishments using the Colombian Annual Manufacturing Survey (AMS) from 1982 to 1998. The United States is used as a benchmark to estimate the reallocation of capital and labor to equalize marginal products across plants in Colombia. Gains are found in manufacturing Total Factor Productivity (TFP) of approximately 3-8 percent and TPF is positively correlated with exporting status, age, size, and location in the central region of the country. There is also suggestive evidence that opening the economy in 1991 is associated with an increase in plant productivity levels for firms that export goods. The 1990 reform that reduced dismissal costs is associated with an increase in productivity, while the reform that increased labor costs in 1993 is associated with a decrease in plants productivity. Further work is needed to establish a causal relation between productivity and policy changes
Creative destruction over the business cycle: a stochastic frontier analysis
[[abstract]]This paper examines the within-industry distributions of jobs created and destructed across plants in terms of technical efficiency, technical efficiency change, scale effect, and technical change. It further investigates how these distributions vary with economic activity. By applying the stochastic frontier analysis to plant-level longitudinal data on Taiwan’s 23 two-digit manufacturing industries spanning the period 1992–2003, we find that jobs created (destructed) are disproportionately clustered at plants with lower technical efficiency but higher rate of technical change. A fall in economic activities is associated with a statistically significant decrease (increase) in the fraction of newly created (destructed) jobs accounted for by plants with a higher rate of technical change, indicating that creative destruction is more pronounced during economic contractions.[[journaltype]]國外[[incitationindex]]SSCI[[ispeerreviewed]]Y[[countrycodes]]US
GRADE equity guidelines 3: considering health equity in GRADE guideline development: rating the certainty of synthesized evidence
Objectives:
The aim of this paper is to describe a conceptual framework for how to consider health equity in the Grading Recommendations Assessment and Development Evidence (GRADE) guideline development process.
Study Design and Setting:
Consensus-based guidance developed by the GRADE working group members and other methodologists.
Results:
We developed consensus-based guidance to help address health equity when rating the certainty of synthesized evidence (i.e., quality of evidence). When health inequity is determined to be a concern by stakeholders, we propose five methods for explicitly assessing health equity: (1) include health equity as an outcome; (2) consider patient-important outcomes relevant to health equity; (3) assess differences in the relative effect size of the treatment; (4) assess differences in baseline risk and the differing impacts on absolute effects; and (5) assess indirectness of evidence to disadvantaged populations and/or settings.
Conclusion:
The most important priority for research on health inequity and guidelines is to identify and document examples where health equity has been considered explicitly in guidelines. Although there is a weak scientific evidence base for assessing health equity, this should not discourage the explicit consideration of how guidelines and recommendations affect the most vulnerable members of society
Mesozoic rock suites along western Philippines: Exposed proto-South China Sea fragments?
An ancient oceanic crustal leading edge east of mainland Asia, the proto-South China Sea crust, must have existed during the Mesozoic based on tectonic reconstructions that accounted for the presence of subducted slabs in the lower mantle and the exposed oceanic lithospheric fragments strewn in the Philippine and Bornean regions. Along the western seaboard of the Philippine archipelago, numerous Mesozoic ophiolites and associated lithologies do not appear to be genetically associated with the younger Paleogene-Neogene ocean basins that currently surround the islands. New sedimentological, paleomagnetic, paleontological, and isotopic age data that we generated are presented here, in combination with our previous results and those of others, to reassess the geological make-up of the western Philippine island arc system. We believe that the oceanic lithospheric fragments, associated melanges, and sedimentary rocks in this region are exhumed slivers of the proto-South China Sea ocean plate
Costos por dolor lumbar en una EPS en Cali, Colombia
Objective: To identify the costs for treatment and disability, in workers with low back pain affiliated to an EPS.
Methodology: Descriptive study carried out on a database of 402 members of an EPS in the city of Cali (Colombia), between 2008 and 2011, occupationally active and diagnosed with low back pain with sciatica, radiculopathy and non-specific low back pain. Data on costs, type of treatment and days of disability were collected.
Results: 52% of the patients were men with an average age of 42 years (SD ± 12). 11% of the patients had physical therapy and 27% medical treatment. The total costs generated for the years 2008 and 2011 averaged 14.800.000 millones de pesos colombianos por año.
Conclusiones: Se puede evidenciar que a medida que aumenta el ano cronológico, tanto el número de personas con lumbalgia, como las incapacidades, el número de tratamientos y por lo tanto los costos para su manejo también van aumentando
Giant magnetic-field-induced strain in Ni2MnGa-based polycrystal
Ferromagnetic Ni2MnGa-based alloys play an important role in technological fields, such as smart actuators, magnetic refrigeration and robotics. The possibility of obtaining large non-contact deformation induced by an external perturbation is one of its key strengths for applications. However, the search for materials with low cost, practical fabrication procedures and large signal output under small perturbing fields still poses challenges. In the present study we demonstrate that by judicial choice of substitution on the Mn site, an abrupt magnetostructural transition from a paramagnetic austenite phase to a ferromagnetic martensite one can be tuned to close to room temperature achieving large and reproducible strains. The required magnetic field to induce the strain varies from small values, as low as 0.25 T for 297.4 K and 1.6% of strain, to 8 T for 305 K and 2.6% of strain. Our findings point to encouraging possibilities for application of shape memory alloys in relatively inexpensive, scalable polycrystalline materials
- …