1,356 research outputs found
Catalysts for polyimide foams from aromatic isocyanates and aromatic dianhydrides
Polyimide foam products having greatly improved burn-through and flame-spread resistance are prepared by the reaction of aromatic polyisocyanates with aromatic dianhydrides in the presence of metallic salts of octoic acid. The salts, for example stannous octoate, ferric octoate and aluminum octoate, favor the formation of imide linkages at the expense of other possible reactions
How do Fermi liquids get heavy and die?
We discuss non-Fermi liquid and quantum critical behavior in heavy fermion
materials, focussing on the mechanism by which the electron mass appears to
diverge at the quantum critical point. We ask whether the basic mechanism for
the transformation involves electron diffraction off a quantum critical spin
density wave, or whether a break-down in the composite nature of the heavy
electron takes place at the quantum critical point. We show that the Hall
constant changes continously in the first scenario, but may ``jump''
discontinuously at a quantum critical point where the composite character of
the electron quasiparticles changes.Comment: Revised version with many new references added. To appear as a
topical review in Journal of Physics: Condensed Matter Physics. Two column
version http://www.physics.rutgers.edu/~coleman/online/questions.ps.g
Prevalencia histórica de hábitos saludables, en mujeres de 50 a 70 años diagnosticadas con osteoporosis en las ciudades de San Martín y Junín de Mendoza
Se establece que las mujeres que hoy padecen osteoporosis y que tienen entre 50 a 70 años han tenido a lo largo de sus vidas una regular nutrición y un escaso nivel de práctica de ejercicio y/o actividad física. Se puede sugerir a partir de este estudio, en ámbitos educativos formales y no formales, que se genere entre niñas y mujeres jóvenes, la conciencia de los beneficios que se obtienen con un estilo de vida saludable, y de ser necesario, se puede sugerir realizar los ajustes a nivel curricular que apunten a mejorar su futura calidad de vida
Incidencia del ejercicio de fuerza-resistencia sobre los índices glucémicos en sangre (antes, durante y después de la práctica de los mismos) en sujetos con diabetes mellitus tipo 2.
Entre las diferentes patologías que afectan al ser humano “la diabetes mellitus” es una de las tiene al ejercicio físico como parte indispensable de la prevención y tratamiento. El interés radica en poder llegar a conocer más a fondo la relación que tienen las distintas modalidades de ejercicio físico dentro del tratamiento de la diabetes mellitus tipo II
Non Fermi Liquid behavior in the under-screened Kondo model
Using the Schwinger boson spin representation, we reveal a new aspect to the
physics of a partially screened magnetic moment in a metal, as described by the
spin Kondo model. We show that the residual ferromagnetic interaction
between a partially screened spin and the electron sea destabilizes the Landau
Fermi liquid, forming a singular Fermi liquid with a divergence in the low temperature specific heat coefficient
. A magnetic field tunes this system back into Landau Fermi liquid
with a Fermi temperature proportional to . We discuss a
possible link with field-tuned quantum criticality in heavy electron materials.Comment: References corrected. Minor changes to tex
At the tip of an iceberg: citizen science and active surveillance collaborating to broaden the known distribution of Aedes japonicus in Spain
Background: Active surveillance aimed at the early detection of invasive mosquito species is usually focused on seaports and airports as points of entry, and along road networks as dispersion paths. In a number of cases, however, the first detections of colonizing populations are made by citizens, either because the species has already moved beyond the implemented active surveillance sites or because there is no surveillance in place. This was the case of the first detection in 2018 of the Asian bush mosquito, Aedes japonicus, in Asturias (northern Spain) by the citizen science platform Mosquito Alert. Methods: The collaboration between Mosquito Alert, the Ministry of Health, local authorities and academic researchers resulted in a multi-source surveillance combining active field sampling with broader temporal and spatial citizen-sourced data, resulting in a more flexible and efficient surveillance strategy. Results: Between 2018 and 2020, the joint efforts of administrative bodies, academic teams and citizen-sourced data led to the discovery of this species in northern regions of Spain such as Cantabria and the Basque Country. This raised the estimated area of occurrence of Ae. japonicus from < 900 km2 in 2018 to > 7000 km2 in 2020. Conclusions: This population cluster is geographically isolated from any other population in Europe, which raises questions about its origin, path of introduction and dispersal means, while also highlighting the need to enhance surveillance systems by closely combining crowd-sourced surveillance with public health and mosquito control agencies’ efforts, from local to continental scales. This multi-actor approach for surveillance (either passive and active) shows high potential efficiency in the surveillance of other invasive mosquito species, and specifically the major vector Aedes aegypti which is already present in some parts of Europe. Graphical abstract: [Figure not available: see fulltext.] © 2021, The Author(s)
Incidencia de un plan de ejercicio físicos específicos de estimulación neuropsicomotora en los niveles de deterioro cognitivo (DC) en adultos mayores del Htal. Luis Lagomaggiore de Mendoza
Se enfatiza que con un plan de anual de ejercicios específicos deestimulación neuropsicomotora, se impacta favorablemente no solamente en superardeterioro y deficiencias a nivel físico sino también con cambios significativos a nivelcognitivo, conductual y social. Inferimos y proponemos para próximos estudios, que con laevaluación de la condición y función física en el consultorio, se podría detectar el riesgo dedesarrollar de DC preclínico, sin necesidad de recurrir a neuroimágenes o a pruebasneurocognitivas más complejas
Sources of pro-cyclicality in east Asian financial systems
Procyclicality is a normal feature of economic systems, but financial sector
weaknesses can exacerbate it sufficiently to pose a threat to macroeconomic and financial
stability. These include shortcomings in bank risk management and governance, in
supervision and in terms of dependence on volatile sources of funds. The paper tests
econometrically for the importance of such features leading to pro-cyclicality in the financial
systems of 11 East Asian countries. This analysis makes it possible to identify specific policy
measures for East Asian countries that could limit the extent to which financial systems
exacerbate pro-cyclicality
Genetic connectivity between Atlantic bluefin tuna larvae spawned in the Gulf of Mexico and in the Mediterranean Sea
The highly migratory Atlantic bluefin tuna (ABFT) is currently managed as two distinct stocks, in accordance with natal homing behavior and population structuring despite the absence of barriers to gene flow. Larval fish are valuable biological material for tuna molecular ecology. However, they have hardly been used to decipher the ABFT population structure, although providing the genetic signal from successful breeders. For the first time, cooperative field collection of tuna larvae during 2014 in the main spawning area for each stock, the Gulf of Mexico (GOM) and the Mediterranean Sea (MED), enabled us to assess the ABFT genetic structure in a precise temporal and spatial frame exclusively through larvae. Partitioning of genetic diversity at nuclear microsatellite loci and in the mitochondrial control region in larvae spawned contemporarily resulted in low significant fixation indices supporting connectivity between spawners in the main reproduction area for each population. No structuring was detected within the GOM after segregating nuclear diversity in larvae spawned in two hydrographically distinct regions, the eastern GOM (eGOM) and the western GOM (wGOM), with the larvae from eGOM being more similar to those collected in the MED than the larvae from wGOM. We performed clustering of genetically characterized ABFT larvae through Bayesian analysis and by Discriminant Analysis of Principal Components (DAPC) supporting the existence of favorable areas for mixing of ABFT spawners from Western and Eastern stocks, leading to gene flow and apparent connectivity between weakly structured populations. Our findings suggest that the eastern GOM is more prone for the mixing of breeders from the two ABFT populations. Conservation of this valuable resource exploited for centuries calls for intensification of tuna ichthyoplankton research and standardization of genetic tools for monitoring population dynamics.This collaborative study was supported by “ECOLATUN” PROJECT CTM2015-68473-R (MINECO/FEDER) funded by Spanish Ministry of Economy and Competitiveness; “TUNAGEN” project funded by Instituto Español de Oceanografía (IEO); and “BLUEFIN” project financed by IEO and Balearic Island Observing and Forecasting System (SOCIB). This research was funded by NASA (NNX11AP76G S07), the NOAA National Marine Fisheries Science Service through the Southeast Fisheries Science Center, as well as by the Cooperative Institute for Marine and Atmospheric Studies under Cooperative Agreement NA15OAR43200064 at the University of Miami, Miami, FL, USA. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.En prens
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