5,160 research outputs found
High Angular Resolution Observations of the Collimated Jet Source Associated with a Massive Protostar in IRAS 16547-4247
A triple radio source recently detected in association with the luminous
infrared source IRAS 16547-4247 has been studied with high angular resolution
and high sensitivity with the Very Large Array at 3.6 and 2 cm. Our
observations confirm the interpretation that the central object is a thermal
radio jet, while the two outer lobes are most probably heavily obscured HH
objects. The thermal radio jet is resolved angularly for the first time and
found to align closely with the outer lobes. The opening angle of the thermal
jet is estimated to be , confirming that collimated outflows can
also be present in massive protostars. The proper motions of the outer lobes
should be measurable over timescales of a few years. Several fainter sources
detected in the region are most probably associated with other stars in a young
cluster.Comment: 9 pages, 2 figure
Desarrollo Económico Local : Caracterización y financiamiento a las MIPYMES de los rubros artesania y madera, muble en el Municipio de Catarina, en el periodo 2013-2015
Desde hace pocos años el municipio de Catarina ha sufrido un dinamismo económico basado principalmente en el turismo nacional gracias a sus bellezas naturales, clima y cercanía con otros municipios con atracciones turísticas similares. Al ser un municipio pequeño y semi rural, las MIPYMES han jugado un papel fundamental en la transformación de vida de sus pobladores en todos los aspectos, ya sean estas familiares o no los cuales son la principal fuente de empleo sostenido dentro del municipio.
El presente trabajo trata de la caracterización y financiamiento al que tiene acceso a las MIPYMES de artesanías y madera-mueble en el municipio de Catarina del departamento de Masaya. En este departamento la mayor parte de las MIPYMES se dedican a la elaboración de artesanías y proveer mano de obra al sector servicio, sin embargo, el municipio de Catarina se caracteriza por creación de artesanías en barro, madera bambú, la venta de plantas ornamentales, así como a la confección de ropa.
En el primer capítulo abordaremos los aspectos teóricos y metodológicos, la importancia o justificación de la investigación. Así como el marco teórico conceptual donde se reflejan los antecedentes y las bases teóricas científicas referente al financiamiento de las MIPYME, así como la recopilación de la información, los instrumentos a utilizar y el proceso del tratamiento de la información
Cellular Models for River Networks
A cellular model introduced for the evolution of the fluvial landscape is
revisited using extensive numerical and scaling analyses. The basic network
shapes and their recurrence especially in the aggregation structure are then
addressed. The roles of boundary and initial conditions are carefully analyzed
as well as the key effect of quenched disorder embedded in random pinning of
the landscape surface. It is found that the above features strongly affect the
scaling behavior of key morphological quantities. In particular, we conclude
that randomly pinned regions (whose structural disorder bears much physical
meaning mimicking uneven landscape-forming rainfall events, geological
diversity or heterogeneity in surficial properties like vegetation, soil cover
or type) play a key role for the robust emergence of aggregation patterns
bearing much resemblance to real river networks.Comment: 7 pages, revtex style, 14 figure
Electroencephalographic Rhythms in Alzheimer's Disease
Physiological brain aging is characterized by synapses loss and neurodegeneration that slowly lead to an age-related decline of cognition. Neural/synaptic redundancy and plastic remodelling of brain networking, also due to mental and physical training, promotes maintenance of brain activity in healthy elderly subjects for everyday life and good social behaviour and intellectual capabilities. However, age is the major risk factor for most common neurodegenerative disorders that impact on cognition, like Alzheimer's disease (AD). Brain electromagnetic activity is a feature of neuronal network function in various brain regions. Modern neurophysiological techniques, such as electroencephalography (EEG) and event-related potentials (ERPs), are useful tools in the investigation of brain cognitive function in normal and pathological aging with an excellent time resolution. These techniques can index normal and abnormal brain aging analysis of corticocortical connectivity and neuronal synchronization of rhythmic oscillations at various frequencies. The present review suggests that discrimination between physiological and pathological brain aging clearly emerges at the group level, with suggested applications also at the level of single individual. The possibility of combining the use of EEG together with biological/neuropsychological markers and structural/functional imaging is promising for a low-cost, non-invasive, and widely available assessment of groups of individuals at-risk
Designing school reopening in the COVID-19 pre-vaccination period in Bogotá, Colombia: A modeling study
The COVID-19 pandemic has affected millions of people around the world. In Colombia,
1.65 million cases and 43,495 deaths were reported in 2020. Schools were closed in many
places around the world to slow down the spread of SARS-CoV-2. In Bogotá, Colombia,
most of the public schools were closed from March 2020 until the end of the year. School
closures can exacerbate poverty, particularly in low- and middle-income countries. To reconcile
these two priorities in health and fighting poverty, we estimated the impact of school
reopening for in-person instruction in 2021. We used an agent-based model of SARS-CoV-
2 transmission calibrated to the daily number of deaths. The model includes schools that
represent private and public schools in terms of age, enrollment, location, and size. We simulated
school reopening at different capacities, assuming a high level of face-mask use, and
evaluated the impact on the number of deaths in the city. We also evaluated the impact of
reopening schools based on grade and multidimensional poverty index. We found that
school at 35% capacity, assuming face-mask adherence at 75% in>8 years of age, had a
small impact on the number of deaths reported in the city during a third wave. The increase
in deaths was smallest when only pre-kinder was opened, and largest when secondary
school was opened. At larger capacities, the impact on the number of deaths of opening
pre-kinder was below 10%. In contrast, reopening other grades above 50% capacity substantially
increased the number of deaths. Reopening schools based on their multidimensional
poverty index resulted in a similar impact, irrespective of the level of poverty of the
schools that were reopened. The impact of schools reopening was lower for pre-kinder
grades and the magnitude of additional deaths associated with school reopening can be
minimized by adjusting capacity in older grades.https://orcid.org/0000-0002-8165-3198Revista Internacional - No indexadaN
An application of life cycle assessment (LCA) within the Catalonian building sector: A case study
Life Cycle Assessment (LCA) tool has been applied to evaluate environmental impacts through the whole building life cycle. LCA has been carried out in accordance to the international standard of ISO 14040 and ISO 14044. As a reference, an application of LCA has been made to a Catalan house located in Barcelona, Spain with a projected 50 years life span. In this work, construction, use (operationand maintenance) and end-of-life phases have been considered. The operational energy consumed during thedwelling period was modeled using a mix of electrical power for electrical appliances, illumination, heating and cooling; and using thermal energy from natural gas for domestic hot water and cooking. Result shows that the highest environmental impacts during the dwelling’s life cycle took place during the use hase. The total impact of global warming potential was 4.52+01 kgCO2-Equiv. m-2 a-1 of which use phase accountedfor 92% (operation 90% and maintenance 2%), construction represented 7% and end-of-life contributed less than 1%. Regarding the operation phase, cooling had the highest environmental burden with 33%, heating represented 9%, followed by illumination 26% and electrical appliances 19%. The other two household activities accountedfor less than 12% (domestic hot water 9% and cooking 4%) of total phase. During the construction phase, the production of building materials represented about 97%, transport to the job site 2% and waste management 1% of total phase. The total primary energy demand was 5.26E+01 MJ m-2 a-1 (gross calorific value) of which non renewableprimary energy demand represents 78% and renewable energy demand 22%. In summary, data for a Catalan home has been provided to evaluate environmental impacts using LCA tool. Data have been modelled into the Gabi software system. Finally, LCA is a suitable tool to evaluate environmental impacts throughout all phases of the building life cycle
Factors Associated With Within-Herd Transmission of Serotype A Foot-and-Mouth Disease Virus in Cattle, During the 2001 Outbreak in Argentina: A Protective Effect of Vaccination
Argentina suffered an extensive foot-and-mouth disease (FMD) epidemic between July 2000 and January 2002, 3months after obtaining the official FMD-free without vaccination status conferred by the World Organization for Animal Health. This is one of the largest FMD epidemics controlled by implementation of a systematic mass vaccination campaign in an FMD-free country. In 2000, 124 herds were reported as FMD positive, 2394 herds in 2001 and one in January 2002; the total number of cattle herds in the country at that time was approximately 230000. Estimates of FMD transmission are important to understand the dynamics of disease spread and for estimating the value for the parameterization of disease transmission models, with the ultimate goals of predicting its spread, assessing and designing control strategies, conducting economic analyses and supporting the decision-making process. In this study, the within-herd coefficient of transmission, β, was computed for herds affected in the 2001 FMD epidemic and categorized as low or high based on the median value of β. A logistic regression model was fitted to identify factors significantly associated with high values of β. Results suggested that the odds of having a high within-herd transmission were significantly associated with time from initial herd infection to disease detection, date of report, vaccination, and time from initial herd infection to herd vaccination. Results presented in this study demonstrate, in quantifiable terms, the protective impact of vaccination in reducing FMD transmission in infected herds. These results will be useful for the parameterization of epidemiological models aimed at quantifying the impact of vaccination and for the design and implementation of FMD emergency vaccination strategies in face of an epidemic.Fil: Brito, B. P.. University of California at Davis; Estados Unidos. Universidad Nacional de Rosario; ArgentinaFil: Perez, Andres Maximiliano. University of California at Davis; Estados Unidos. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cosentino, B.. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Rodriguez, L. L.. No especifíca;Fil: König, Guido Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentin
Does the Urinary Calcium/Citrate Ratio Add to the Diagnostic Workup of Children at Risk of Kidney Stones? A Cross-Sectional Study
The purpose of the study was to evaluate urinary citrate/creatinine (U Ci /U Cr ) and urinary calcium/citrate (U Ca /U Ci ) ratios for distinguishing stone formers (SF) from non-stone formers (NSF) in an at-risk population. This was a retrospective study that included all pediatric patients who underwent urinary citrate testing from April 2017 to March 2018. The urinary levels of citrate, calcium, sodium, potassium, creatinine, oxalate, urate, pH, and specific gravity (SG) were measured in our clinical laboratory. Diagnosis of kidney stones was obtained through chart review. A total of 97 patients were included (46 NSF and 51 SF). The U Ci /U Cr ratio was not significantly different between NSF and SF. Median U Ca /U Cr ratio was higher in SF (0.67) compared with NSF (0.21, p \u3c 0.0001). The median ratio of U Ca /U Ci was also higher in SF (1.30) than in NSF (0.65, p = 0.001). Oxalate, urate, pH, SG, and urinary sodium/potassium ratio did not differentiate between the SF and NSF. Positive correlation was seen between U Ca /U Cr and urinary sodium/creatinine U Na /U Cr (p \u3c 0.0001), as well as between U Ca /U Cr and U Ci /U Cr (p \u3c 0.0001). The study has demonstrated significantly higher U Ca /U Ci and U Ca /U Cr in SF compared with NSF, while the use of urinary oxalate, urate, pH, and SG did not differentiate between SF from NSF. We also confirmed a positive correlation between U Na /U Cr and U Ca /U Cr . While the utility of U Ca /U Cr is well established, our data suggest that U Ca /U Ci rather than U Ci /U Cr may be more predictive in the clinical setting when evaluating for nephrolithiasis
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