25 research outputs found
Connexin-36 protects against suddent infant death syndrome
The sudden infant death syndrome (SIDS) is the main cause of postneonatal infant death; however the etiology of SIDS remains ill defined. The hypothesis that SIDS, or a subset of SIDS, is due to an abnormal brainstem mechanism is one of the current leading hypotheses on SIDS etiology. The brainstem is essential for cardiac and respiratory function, controlling autonomic and homeostatic responses including breathing, central chemosensitivity, heartbeat and blood pressure, all mechanisms that are thought to be involved in SIDS. Connexin-36 (Cx36), the principal component of neuron-to-neuron channels that form the electrical synapses, is present in the specific neural populations of brainstem region involved in the CO2 chemoreception and respiratory control, and its expression is unregulated during this critical period of life. Accordingly, we postulate that Cx36 would be a key element in the pathogenesis of SIDS. To address this issue we have studied how the genetic suppression of Cx36 expression affects to the respiratory pacemaker, central chemoreflexes, cardiorespiratory coupling, and risk for SIDS. Mice lacking Cx36 at postnatal day 14 showed in comparison with control wild-type greater variability in the respiratory rhythmicity, abnormally enhanced ventilatory responses to hypoxia and hypercapnia, more cardiorespiratory phase synchronization and less respiratory sinus arrhythmia. A combination of low O2 and high CO2 content in inspired air was used as exogenous stressor of SIDS; under these conditions all wild-type mice survived while the 40% of Cx36-knockout animals succumbed by respiratory failure
Responses of fruit physiology and virgin oil quality to cold storage of mechanically harvested ‘Arbequina’ olives cultivated in hedgerow
The increase in olive fruit production (Olea europaea L.
cv. ‘Arbequina’), due to the increasing use of super-intensive
cultivation and the need for a rapid fruit processing will force
the industry to make a considerable investment in machinery
for processing in order to maintain the level of quality of virgin
olive oil (VOO). This work aims to study how the storage
temperature affects the physiology of the olive and the
quality of the oil, in order to use fruit storage as a cheaper
and more versatile alternative to the increase in processing
capacity. ‘Arbequina’ fruit did not present symptoms of
chilling injury during 15 days of cold-storage. Postharvest decay, de-greening, softening, respiration and ethylene
production of the olive fruit increased in direct relationship as
the storage temperature increased. These facts determined a
proportional deterioration of the free acidity and the sensory
quality of the VOOs. Furthermore, the contents of tocopherols
and of the main phenolic compounds in the VOO exhibited a
reduction during fruit storage according to the increase in the
temperature used. Storage at 2 °C preserved the integrity of
the olive to maintain the best “Extra” level of VOO quality for
a period of 12 days.El aumento de la producción de aceituna (Olea europaea
L. cv. ‘Arbequina’), debido al uso creciente del cultivo superintensivo
y la necesidad de un rápido procesamiento del fruto
forzará a la industria a hacer una considerable inversión en
maquinaria para el procesado, para mantener el nivel de calidad
del aceite de oliva virgen (AOV). Este trabajo pretende
estudiar cómo la temperatura de almacenamiento afecta a la
fisiología de la aceituna y a la calidad del aceite, en orden de
usar la conservación del fruto como una alternativa más barata
y versátil al aumento de la capacidad de procesamiento.
La aceituna ‘Arbequina’ no presentó síntomas de daños por
frío durante 15 días de frigoconservación. La podredumbre,
el desverdizado, el ablandamiento, la respiración y la producción
de etileno de la aceituna aumentaron en relación directa
a como aumentaba la temperatura de conservación. Estos
hechos determinaron un deterioro proporcional de la acidez
libre y de la calidad sensorial de los AOVs. Además, los contenidos
de tocoferoles y de los principales grupos de compuestos
fenólicos en los AOVs experimentaron una reducción
durante la conservación del fruto en razón directa a la
temperatura de almacenamiento utilizada. La frigoconservación
a 2 °C preservó la integridad del fruto para mantener el
nivel «Extra» de calidad durante un periodo de 12 días.This experiment was funded by the Spanish Ministry of Science and Innovation, research project AGL2009-11310/AGR and by the European Regional Development Fund (ERDF) research project 0042-RISE-5-E. Thanks are due to the owners of Internacional Olivarera, S.A. (Interoliva), for allowing us to conduct the experiments in the Sanabria farm. Antonio Montero helped us with the field measurements and M. C. Martinez for technical assistance in the laboratory. We also thank Silvia Seller, agronomist, and Juan Francisco Bernal* foreman, for their technical assistance
Upstream migration of anadromous and potamodromous brown trout: patterns and triggers in a 25-year overview
Producción CientíficaRiver fragmentation and alterations in
flow and thermal regimes are the main stressors
affecting migrating fish, which could be aggravated by
climate change and increasing water demand. To
assess these impacts and define mitigation measures, it
is vital to understand fish movement patterns and the
environmental variables affecting them. This study
presents a long-term (1995–2019) analysis of
upstream migration patterns of anadromous and
potamodromous brown trout in the lower River
Bidasoa (Spain). For this, captures in a monitoring
station were analyzed using Survival Analysis and
Random Forest techniques. Results showed that most
upstream movements of potamodromous trout
occurred in October–December, whereas in June–July
for anadromous trout, although with differences
regarding sex and size. Both, fish numbers and dates
varied over time and were related to the environmental
conditions, with different influence on each ecotype.
The information provided from comparative studies
can be used as a basis to develop adaptive management
strategies to ensure freshwater species conservation.
Moreover, studies in the southern distribution range
can be crucial under climate warming scenarios, where
species are expected to shift coldwards.Proyecto de innovación docente de la Universidad de Valladolid (PIF-UVa 2017)Ministerio de Ciencia, Innovación y Universidades (grant PTQ2018-010162)Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL
Decentralized Resource Allocation in Application Layer Networks
architectures that allow the provisioning of services requiring a huge amount of resources by connecting large numbers of individual computers. The ALN simulation project CATNET evaluates a decentralized mechanism for resource allocation in ALN, which is based on the economic paradigm of the Catallaxy, against a centralized mechanism using an arbitrator object. In both versions, software agents buy and sell network services and resources to and from each other. The economic model is based on self-interested maximization of utility and self-interested cooperation between agents. This article describes the design of money and message flows for centralized and decentralized coordination in both versions and shows preliminary results
Self-organizing resource allocation for autonomic network
Application-layer networks (ALN) are software architectures that allow the provisioning of services requiring a huge amount of resources by connecting large numbers of individual computers, e.g. Grids and P2P-Networks. Self-organization, like proposed by the Autonomic Computing concept, might be the key to controlling these systems. The CATNET project evaluates a decentralized mechanism for resource allocation in ALN, based on the economic paradigm of the Catallaxy. The economic model is based on self-interested maximization of utility and self-interested cooperation between software agents, who buy and sell network services and resources to and from each other
Advantages and insights from a hierarchical Bayesian growth and dynamics model based on salmonid electrofishing removal data
Growth is a fundamental ecological process of stream-dwelling salmonids which is strongly interrelated to critical life history events (emergence, mortality, sexual maturity, smolting, spawning). The ability to accurately model growth becomes critical when making population predictions over large temporal (multi-decadal) and spatial (meso) scales, e.g., investigating the effect of global change. Body length collection by removal sampling is a widely-used practice for monitoring fish populations over such large scales. Such data can be efficiently integrated into a Hierarchical Bayesian Model (HBM) and lead to interesting findings on fish dynamics. We illustrate this approach by presenting an integrated HBM of brown trout (Salmo trutta) growth, population dynamics, and removal sampling data collection processes using large temporal and spatial scales data (20 years; 48 sites placed along a 100 km latitudinal gradient). Growth and population dynamics are modelled by ordinary differential equations with parameters bound together in a hierarchical structure. The observation process is modelled with a combination of a Poisson error, a binomial error, and a mixture of Gaussian distributions. Absolute fit is measured using posterior predictive checks, those results indicate that our model fits the data well. Results indicate that growth rate is positively correlated to catchment area. This result corroborates those of other studies (laboratory, exploratory) that identified factors besides water temperature that are related to daily ration and have a significant effect on stream-dwelling salmonid growth at a large scale. Our study also illustrates the value of integrated HBM and electrofishing removal sampling data to study in situ fish populations over large scales
Dynamic pan, tilt and zoom adjustment for perception triggered response
Natural environmental cues can properly guide the robot towards its goal. But often landmarks are difficult to be recognised by the robot when it is moving. Dynamic orientation of the camera's parameters, fixing the attention of the visual system on relevant environmental features, can greatly improve vision based landmark identification. This paper present an approach for sonar and compass based dynamic selection of pan, tilt and zoom values
Adapting the Point of View for Behavior-based Navigation
Perception triggered response behavior together with the selection of the appropriate environmental cues can properly guide the robot towards its goal
Web Caching and Content Delivery
Introduction of new services on the Internet is a laborious, time-consuming task. Application networks, applications being serviced through multiple interconnected service nodes disseminated across the Internet, are as well costly to set up. This paper investigates dynamic deployment mechanisms to realize application network service introduction on the Internet