1,448 research outputs found
Why the Kuznets Curve will always Reverse ?
In this paper, we develop a model of innovation-based growth to address the issue of skill-biased technical change over the long run. We show that innovations fluctuate endogenously from skill-intensive to unskilled-intensive sectors, thereby generating periods of increasing and decreasing wage inequality. This could contribute to explain that technological progress exerts a non monotonic pressure on wage inequality over the long run.J31; O31; O41
Performance Portability Study of Linear Algebra Kernels in OpenCL
The performance portability of OpenCL kernel implementations for common
memory bandwidth limited linear algebra operations across different hardware
generations of the same vendor as well as across vendors is studied. Certain
combinations of kernel implementations and work sizes are found to exhibit good
performance across compute kernels, hardware generations, and, to a lesser
degree, vendors. As a consequence, it is demonstrated that the optimization of
a single kernel is often sufficient to obtain good performance for a large
class of more complicated operations.Comment: 11 pages, 8 figures, 2 tables, International Workshop on OpenCL 201
Tracing the glycogen cells with protocadherin 12 during mouse placenta development.
International audienceAmong the different trophoblast subtypes of the mouse placenta, the glycogen cells (GC) are one of the trophoblast subtypes that invade the decidua. We previously established that GC specifically expressed protocadherin 12 (PCDH12). In this paper, we investigated the origin of the PCDH12-positive cells and we characterized their fate in the maternal tissues. Our data indicate that they directly originate from the central part of the ectoplacental cone at embryonic day (E) 7.5. PCDH12-positive cells start to accumulate glycogen from E10.5 and the first migrating cells could be observed from this age. Unlike other placental and decidual cells, GC do not express P-cadherin, which may explain their migration properties in this organ. In the decidua, GC settle in the vicinity of the maternal vascular sinuses but do not incorporate in the endothelium. By the end of gestation (E17.5), most GC islets of the decidua enter into a lytic phase and form large lacunae. These lacunae, filled with glycogen, may provide a substantial source of energy at the end of gestation or during delivery. Our data suggest that spongiotrophoblasts and GC are two independent lineages and we bring insights into GC migration and fate
Sobre la producción de saberes en los movimientos sociales : notas sobre el Centro de Investigación Soldati en la Ciudad Autónoma de Buenos Aires
Este trabajo propone indagar en un aspecto en particular de las experiencias de los Bachilleratos Populares (BP), aquél vinculado a la producción y creación colectiva de conocimiento y la necesidad de problematizar y articular las prácticas de él/la educador/a
popular con las de el/la investigador/a social desde los mismos BP. Tal preocupación e
interés radica en la consideración de que la realidad social actual presenta facetas muy
distantes al contexto de emergencia de los BP, presentando fenómenos y problemáticas nuevas que muchas veces desconocemos, lo que nos lleva a concebir un nuevo armamentode técnicas y conceptos que nos permitan entrar en contacto con esa misma realidad, tanto al interior como al exterior del espacio-aula, para ahondar en el conocimiento, problematización y entendimiento de la cultura popular en sus particulares expresiones históricas teniendo en cuenta una nueva articulación entre: el espacio propio del BP, el“(des)conocimiento" de la realidad más inmediata dentro de la cual estamos insertos/a, nuestro propio papel como educadores/as populares y la asunción de una actitud más vinculada al rol de un “investigador militante", lo que creemos nos lleva directamente a un desafío metodológico, epistemológico y político que consideramos necesario asumir y cuyo planteamiento intentaremos plasmar aquí a modo de hipótesis generales.Fil: Olivero, Laura. Universidad Nacional de San Martín.Fil: Tillet, Agustín. Universidad Nacional de San Martín
What is the best way to evaluate an acute traumatic knee injury?
The Ottawa Knee Rules can guide the use of radiography in adults who present with isolated knee pain. However, information on use of these rules in the pediatric population is limited (strength of recommendation [SOR ]: A, based on systematic review of high-quality studies and a validated clinical decision rule). Specific physical examination maneuvers (such as the Lachman and McMurray tests) may be helpful when assessing for meniscal or ligamentous injury (SOR : C, based on studies of intermediate outcomes)
The "Ram Effect": A "Non-Classical" Mechanism for Inducing LH Surges in Sheep
During spring sheep do not normally ovulate but exposure to a ram can induce ovulation. In some ewes an LH surge is induced immediately after exposure to a ram thus raising questions about the control of this precocious LH surge. Our first aim was to determine the plasma concentrations of oestradiol (E2) E2 in anoestrous ewes before and after the "ram effect" in ewes that had a "precocious" LH surge (starting within 6 hours), a "normal" surge (between 6 and 28h) and "late» surge (not detected by 56h). In another experiment we tested if a small increase in circulating E2 could induce an LH surge in anoestrus ewes. The concentration of E2 significantly was not different at the time of ram introduction among ewes with the three types of LH surge. "Precocious" LH surges were not preceded by a large increase in E2 unlike "normal" surges and small elevations of circulating E2 alone were unable to induce LH surges. These results show that the "precocious" LH surge was not the result of E2 positive feedback. Our second aim was to test if noradrenaline (NA) is involved in the LH response to the "ram effect". Using double labelling for Fos and tyrosine hydroxylase (TH) we showed that exposure of anoestrous ewes to a ram induced a higher density of cells positive for both in the A1 nucleus and the Locus Coeruleus complex compared to unstimulated controls. Finally, the administration by retrodialysis into the preoptic area, of NA increased the proportion of ewes with an LH response to ram odor whereas treatment with the α1 antagonist Prazosin decreased the LH pulse frequency and amplitude induced by a sexually active ram. Collectively these results suggest that in anoestrous ewes NA is involved in ram-induced LH secretion as observed in other induced ovulators
Reviewing, indicating, and counting books for modern research evaluation systems
In this chapter, we focus on the specialists who have helped to improve the
conditions for book assessments in research evaluation exercises, with
empirically based data and insights supporting their greater integration. Our
review highlights the research carried out by four types of expert communities,
referred to as the monitors, the subject classifiers, the indexers and the
indicator constructionists. Many challenges lie ahead for scholars affiliated
with these communities, particularly the latter three. By acknowledging their
unique, yet interrelated roles, we show where the greatest potential is for
both quantitative and qualitative indicator advancements in book-inclusive
evaluation systems.Comment: Forthcoming in Glanzel, W., Moed, H.F., Schmoch U., Thelwall, M.
  (2018). Springer Handbook of Science and Technology Indicators. Springer Some
  corrections made in subsection 'Publisher prestige or quality
Brote de gastroenteritis por agua potable de suministro público
ResumenIntroducciónLa potabilidad del agua induce a descartar el posible origen hídrico de los brotes. El objetivo fue investigar un brote de gastroenteritis por agua potable de suministro público.MétodosDespués de la notificación de un brote de gastroenteritis en el municipio de Baqueira (Valle de Arán) se diseñó un estudio epidemiológico de cohortes retrospectivo. Mediante un muestreo sistemático se eligió a 87 personas hospedadas en los hoteles y a 62 alojadas en diferentes apartamentos. Se recogió información sobre 4 factores (consumo de agua de la red, bocadillos, agua y alimentos en las pistas de esquí) y presencia de síntomas. Se determinó la existencia de cloro, se analizó el agua de la red y se realizó un coprocultivo a 4 enfermos. La implicación de cada factor se determinó con el riesgo relativo (RR) y su intervalo de confianza (IC) del 95%.ResultadosLa incidencia de gastroenteritis fue del 51,0% (76/149). Los porcentajes de los síntomas fueron los siguientes: fiebre, 27,0%; diarrea, 87,5%; náuseas, 50,7%; vómitos, 30,3%, y dolor abdominal, 80,0%. El único factor que presentó un riesgo estadísticamente significativo fue el consumo de agua de la red (RR = 11,0; IC del 95%, 1,6-74,7). La calificación sanitaria del agua fue de potabilidad. Se observó un defecto de situación del clorador en el depósito, que fue corregido. Se recomendó incrementar aún más las concentraciones de cloro, lo cual se acompañó de una disminución de los casos. Los coprocultivos de los 4 enfermos fueron negativos para las enterobacterias investigadas.ConclusionesEl estudio demuestra la posibilidad de presentación de brotes hídricos por agua cualificada como potable y sugiere la necesidad de mejorar la investigación microbiológica (determinación de protozoos y virus) en este tipo de brotes.AbstractIntroductionThe chlorination of public water supplies has led researchers to largely discard drinking water as a potential source of gastroenteritis outbreaks. The aim of this study was to investigate an outbreak of waterborne disease associated with drinking water from public supplies.MethodsA historical cohort study was carried out following notification of a gastroenteritis outbreak in Baqueira (Valle de Arán, Spain). We used systematic sampling to select 87 individuals staying at hotels and 67 staying in apartments in the target area.Information was gathered on four factors (consumption of water from the public water supply, sandwiches, water and food in the ski resorts) as well as on symptoms. We assessed residual chlorine in drinking water, analyzed samples of drinking water, and studied stool cultures from 4 patients. The risk associated with each water source and food type was assessed by means of relative risk (RR) and 95% confidence intervals (CI).ResultsThe overall attack rate was 51.0% (76/149). The main symptoms were diarrhea 87.5%, abdominal pain 80.0%, nausea 50.7%, vomiting 30.3%, and fever 27.0%. The only factor associated with a statistically significant risk of disease was consumption of drinking water (RR = 11.0; 95% CI, 1.6-74.7). No residual chlorine was detected in the drinking water, which was judged acceptable. A problem associated with the location of the chlorinator was observed and corrected. We also recommended an increase in chlorine levels, which was followed by a reduction in the number of cases. The results of stool cultures of the four patients were negative for enterobacteria.ConclusionsThis study highlights the potential importance of waterborne outbreaks of gastroenteritis transmitted through drinking water considered acceptable and suggests the need to improve microbiological research into these outbreaks (viruses and protozoa detection)
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