15 research outputs found
Contribución al estudio reológico del néctar de albaricoque
The rheological behaviour of the apricot nectar has been studied. The equations which bind the shear-stress with the angular rate of the viscosimeter, obtained from the corresponding rheograms, and also that ones which establish the dependance between the apparent viscosity of diluted nectars and the corresponding pulp concentration. Through the study of the temperature influence on the rheological parameters were obtained the corresponding equations of exponential type such as K = K0 • eA/T where K0 = constant which is distinctive for each nectar, T = Kelvin temperature and A = constant, whose value is ΔE/R, where ΔE is the activation energy for the flow and R = Gas general constant.Se ha estudiado el comportamiento reológico del néctar de albaricoque estableciéndose las ecuaciones que ligan los esfuerzos cortantes con la velocidad angular del viscosímetro, deducidas de los reogramas correspondientes, y las que relacionan la viscosidad aparente de néctares diluidos del anterior con su concentración en pulpa. Mediante el estudio del efecto de la temperatura sobre los parámetros reológicos se han deducido ecuaciones del tipo K = K0 exp(A/T), donde K0 = cte característica del néctar, T = ta absoluta y A = cte, cuyo valor es ΔE/R, siendo ΔE la energía de activación del flujo y R la cte de los gases
A search for ionized jets towards massive young stellar objects
Radio continuum observations using the Australia telescope compact array at 5.5, 9.0, 17.0 and 22.8 GHz have detected free-free emission associated with 45 of 49 massive young stellar objects and H II regions. Of these, 26 sources are classified as ionized jets (12 of which are candidates), 2 as ambiguous jets or disc winds, 1 as a disc-wind, 14 as H II regions and 2 were unable to be categorized. Classification as ionized jets is based upon morphology, radio flux and spectral index, in conjunction with previous observational results at other wavelengths. Radio luminosity and momentum are found to scale with bolometric luminosity in the same way as low-mass jets, indicating a common mechanism for jet production across all masses. In 13 of the jets, we see associated non-thermal/optically thin lobes resulting from shocks either internal to the jet and/or at working surfaces. 10 jets display non-thermal (synchrotron emission) spectra in their lobes, with an average spectral index of ? =-0.55 consistent with Fermi acceleration in shocks. This shows that magnetic fields are present, in agreement with models of jet formation incorporatingmagnetic fields. Since the production of collimated radio jets is associated with accretion processes, the results presented in this paper support the picture of disc-mediated accretion for the formation of massive stars with an upper limit on the jet phase lasting approximately 6.5×104 yr. Typical mass-loss rates in the jet are found to be 1.4× 10-5M? yr-1 with associated momentum rates of the order of (1-2) × 10-2M? km s-1 yr-1. © 2016 The Authors. Published by Oxford University Press on behalf of The Royal Astronomical Society
Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations
Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24-/- mouse model of HGPS. Challenge of Zmpste24-/- mice with the ß-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24-/- cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24-/- progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death.Peer ReviewedPostprint (published version
Forma entérica o aguda de la intoxicación con helechos en Colombia, 1. Revisión de la literatura y aspectos generales de la enfermedad natural en bovinos
Se describe en el país la forma entérica o aguda de la intoxicación con helechos en bovinos, síndrome hemorrágico tradicionalmente confundido con el carbón bacteridiano, la leptospirosis y la septicemia hemorrágica, enfermedad esta última de dudosa ocurrencia en Colombia. Se hace un recuento detallado de los síntomas y lesiones post-mortem encontradas en animales intoxicados naturalmente, en una zona de clima medio del departamento de Antioquia, de suelos ácidos y enmalezada con helechos, específicamente con Pteridium aquilinum. Se hace énfasis en la metodología diagnóstica utilizada, con el fin de proporcionar al profesional de campo una visión clara del problema, y a través de ésta, las pautas para reconocer y tratar la enfermedad, minimizando así las pérdidas económicas por ella producidasGanado de leche-Ganadería lech
Diseno estandarizado de estanques de acumulacion
170 p.Con el desarrollo industrial del país son cada día más las empresas que requieren del uso de estanques o recipientes para la elaboración, transformación o almacenamiento de sus productos, destacándose, en forma especial, la industria petrolera, petroquímica y química, como usuarios de estos estaques. Como el estanque o recipiente, es el componente básico de la mayoría de estos tipos de equipos de procesos, el profesional que participa en la construcción y avance de la industria pueden verse abocado la tarea de proyectar este tipo de elemento; por lo tanto, es a él a quien va dirigido este trabajo, a fin de que pueda dar una respuesta rápida, racional y económica, dentro de estrictos límites de seguridad
Carbon composite membrane derived from MIL-125-NH2 MOF for the enhanced extraction of emerging pollutants
[eng] Porous carbon derived from amine-functionalized MIL-125 metal-organic framework (C-MIL-125-NH2) was prepared by carbonization at high temperature under inert atmosphere, and used for adsorption of bisphenol A (BPA) and 4-tert-butylphenol (4-tBP). The obtained carbon showed bimodal porosity and fast extraction of both pollutants in batch conditions following a pseudo-second-order model. The adsorption mechanism was studied by the measurement of zeta potential, and the results suggested that π-π stacking interactions between the carbon material and the phenol molecules probably are the main sorption mechanism. The prepared C-MIL-125-NH2 was incorporated into mechanically stable membranes for flow-through solid-phase extraction of studied phenols prior to HPLC analysis. The hybrid material showed excellent permeance to flow, easy regeneration and good performance for the simultaneous enrichment of mixtures of BPA and 4-tBP, facilitating their determination when present at low concentration levels
Evaluación de calidad en frutos de 41 genotipos de nanche (Byrsonima crassifolia L. HBK) de Nayarit, México
Nanche is a harvest fruit whose fruits are prized for their
bittersweet. The objective was to evaluate the quality of
fruits of 41 nanche genotypes (Byrsonima crassifolia L.
HBK) from the warm climate of Nayarit, Mexico. The
quality variables analyzed in the fruit were: color, fresh
weight (PFF), length (LF), diameter (DF), total soluble
solids (°Brix), titratable acidity (percentage of citric acid)
and pH of fruit. Furthermore, the dry weight of the seed (PSS)
was determined. Multivariate statistical analysis of main
components for data processing was used. Three principal
components (CP's) explained 80.61% of total variance (VT).
CP1 contributed with 38.58 of VT, where morphological
variables of importance were: weight, diameter, length and
size of the fruit while in CP2 represented 24.78% of VT,
where chemical characteristics were relevant: percentage
of citric acid pulp (AC) and pH of fruit juice. In CP3 were
important total soluble solids (°Brix), and °Brix/pH ratio of
the pulp that contributed with 17.25% of total variance. The
°Brix/AC ratio, plus weight, size and yellowing of skin of the
fruit were quality parameters that could be used as genetic
qualities to select nanche genotypesEl nanche es un frutal de recolección cuyos frutos son
apreciados por su sabor agridulce. El objetivo fue evaluar
la calidad en frutos de 41 genotipos de nanche (Byrsonima
crassifolia L. HBK) procedentes de la zona de clima cálido
de Nayarit, México. Las variables de la calidad analizadas en
los frutos: color, peso fresco (PFF), longitud (LF), diámetro
(DF), sólidos solubles totales (°Brix), acidez titulable
(porcentaje de ácido cítrico), pH de frutos. Además, se
determinó el peso seco de la semilla (PSS). Se usó análisis
estadístico multivariado de componentes principales
para el procesamiento de datos. Tres componentes
principales (CP�s) explicaron 80.61% de la varianza total
(VT). El CP1 contribuyó con 38.58 de la VT en donde
resultaron de importancia las variables morfológicas: peso,
diámetro, longitud y tamaño de fruto mientras que el CP2
representó 24.78% de la VT, donde resultaron relevantes
las características químicas: porcentaje de ácido cítrico de
la pulpa (AC) y pH del jugo del fruto. En el CP3 resultaron
importantes los sólidos solubles totales (°Brix), y la relación
°Brix/pH de la pulpa que contribuyeron con 17.25% de la
varianza total. La relación °Brix/AC, más el peso, tamaño y color amarillo de la epidermis del fruto fueron los parámetros
de calidad que podrían usarse como cualidades genéticas
para seleccionar genotipos de nanch
"Cora 2012": híbrido intervarietal de maíz para Nayarit y regiones similares
The intervarietal Cora hybrid of maize 2012 was developed
by the method of Reciprocal Recurrent Selection (RRS).
A heterotic pattern of P * A populations is used. The first
two cycles were with half sib progeny supported by corn
farmers from Nayarit, participatory breeding. From the
third cycle, progeny were from reciprocal full siblings
through crosses between lines S1
, type P S1 * A S1
. Cora
2012 was derived from the third cycle. The formation of
populations (1999-2001) and the implementation of RRS
(2002-2010) were performed in Nayarit. The evaluation was
conducted in Nayarit (2005-2010) and validation included
the states of Jalisco, Michoacán and Sinaloa (2010-2013).
The characterization was made in Nayarit (2010- 2011) and
was assigned as 'MAZ-1477-010313' in the record from the
Catálogo Nacional de Variedades Vegetales (CNVV). Is has
a similar behavior to current maize hybrids of 7 t ha-1. On
average, also have similar agronomic characteristics than
commercial hybrids. Its greatest attribute is that it yields well
even under changing climate factors, technology used and
soil. Seed production is relatively easy and yields around 4.5
t ha-1 of seed. Associated farmers and small seed companies
may use seed from parentsEl híbrido intervarietal de maíz Cora 2012 fue desarrollado
mediante el método de la Selección Recurrente Recíproca
(SSR). Se utiliza el patrón heterótico de las poblaciones
P
* A. Los dos primeros ciclos fueron con progenies de
medios hermanos apoyados por agricultores maiceros de
Nayarit, mejoramiento participativo. Desde el tercer ciclo,
las progenies fueron de hermanos completos recíprocos
mediante cruzamientos entre líneas S1
, tipo P S1 * A S1
.
El Cora 2012 se derivó de este tercer ciclo de avance. La
formación de las poblaciones (1999-2001) y la aplicación
de la SRR (2002-2010) se han realizado en Nayarit. La
evaluación se realizó en Nayarit (2005-2010) y la validación
también incluyó los estados de Jalisco, Michoacán y Sinaloa
(2010-2013). La caracterización se realizó en Nayarit
(2010- 2011) y fue asignado como �MAZ-1477 - 010313�en
el registro del Catálogo Nacional de Variedades Vegetales
(CNVV). Tiene un comportamiento similar a los híbridos
de maíz de actual uso; de 7 t ha-1. En promedio, también
tiene similares características agronómicas que los híbridos
comerciales. Su mayor atributo es que rinde bien aún en
factores cambiantes de clima, tecnología usada y suelo. La
producción de semilla es relativamente fácil y se obtienen como 4.5 t ha-1 de semilla. Agricultores asociados y pequeñas
empresas productoras de semilla pueden disponer de la
semilla de los progenitores
Knowledge elicitation of pedagogical needs for TEL-based minimally invasive surgery learning of multiple skills
Technology enhanced learning (TEL) is nowadays consolidated as a complement for training the different skills required in minimally invasive surgery (MIS). However, its use is fragmented, depending on the availability of TEL resources in hospitals and training centres, addressing individual skills rather than all skills as a whole, and lacking a pedagogical model to support efficient learning. The EASIER project will implement a learning platform supported by a validated pedagogical model and integrate tools and resources to train and assess together all skills required from new surgeons. In this study, we present the early definition stages, in which a knowledge elicitation methodology is developed to capture the know-how of surgeons, engineers and educational psychologists. First results are presented in the form of learning actions and potential means of implementation. This knowledge will be key in defining the pedagogical needs of the platforms