721 research outputs found
Mechanisms of Action and Targets of Nitric Oxide in the Oculomotor System
Nitric oxide (NO) production by neurons in the prepositus hypoglossi (PH) nucleus is necessary for the normal performance of eye movements in alert animals. In this study, the mechanism(s) of action of NO in the oculomotor system has been investigated. Spontaneous and vestibularly induced eye movements were recorded in alert cats before and after microinjections in the PH nucleus of drugs affecting the NO–cGMP pathway. The cellular sources and targets of NO were also studied by immunohistochemical detection of neuronal NO synthase (NOS) and NO-sensitive guanylyl cyclase, respectively. Injections of NOS inhibitors produced alterations of eye velocity, but not of eye position, for both spontaneous and vestibularly induced eye movements, suggesting that NO produced by PH neurons is involved in the processing of velocity signals but not in the eye position generation. The effect of neuronal NO is probably exerted on a rich cGMP-producing neuropil dorsal to the nitrergic somas in the PH nucleus. On the other hand, local injections of NO donors or 8-Br-cGMP produced alterations of eye velocity during both spontaneous eye movements and vestibulo-ocular reflex (VOR), as well as changes in eye position generation exclusively during spontaneous eye movements. The target of this additional effect of exogenous NO is probably a well defined group of NO-sensitive cGMP-producing neurons located between the PH and the medial vestibular nuclei. These cells could be involved in the generation of eye position signals during spontaneous eye movements but not during the VOR.Fondo de Investigación Sanitaria Grants 94/0388 and 97/2054Comunidad Autónoma de Madrid Grant 08.5/0019/1997Dirección General de Investigación Científica y Technológica Grant PB 93–117
La controversia de los agrocombustibles, una propuesta didática para las ciencias para el mundo contemporáneo
Presentamos una propuesta didáctica para llevar a cabo en la nueva materia Ciencias
para el Mundo Contemporáneo (CMC). Elegimos un tema actual y controvertido, como
es el caso de los agrocombustibles (mal llamados biocombustibles) y lo abordamos de
un modo que se convierta en algo atractivo para los alumnos, haciéndoles conocer a
la vez los fundamentos científicos del problema
The feminine face of Science
Uno de los objetivos fijados en la asignatura Ciencias para el mundo contemporáneo (1º de Bachillerato) es el de superar el escaso interés que siente el alumnado hacia la ciencia. Es necesario para tal fin un cambio en los
planteamientos tanto metodológicos como temáticos, respecto a las asignaturas de ciencias tradicionales. Con la intención de contribuir a este cambio se han diseñado actividades en las que confluyen características que
podrán ayudar a conseguirlo. En el caso propuesto se escogió una temática controvertida a lo largo de la historia: Mujeres y Ciencia; eligiendo como estrategia de aprendizaje las webquests y publicando en la red las tareas realizadas por el alumnado, todo esto con la finalidad de romper las paredes del aula y hacer extensiva la cultura científica al resto de la comunidad educativa y público en general
The weaver death in ancient Peru
La muerte, y sus atributos relacionados con el tejido, hilado o destino, por ejemplo, en
los estudios del antiguo Perú apenas han sido investigados. Hay investigaciones a modo de
“islas” sobre los restos en contextos funerarios, sobre la figura de Supay, o seres del
inframundo, pero, realmente no hay un trabajo que haya realizado un “tejido” con aquellas
características que presentan gran similitud, y que perfilan la Muerte y sus atributos como
tejedora del destino. Es más, ¿qué sabemos sobre una deidad o deidades asociadas a la muerte,
atributos, cualidades, relacionadas con el tejido y la temporalidad? En general los estudios
sobre las características de una deidad apenas han sido desarrollados en esta área,
expondremos, que realmente hay características suficientes para hablar de la muerte como una
deidad, con una serie de características relacionadas, en este caso, con el “hilo” de la vidamuerte.Death, and its attributes related to weaving, spinning, or destiny, for example. In the studies of
ancient Peru they have hardly been investigated. There are investigations, about the remains in
funeral contexts, about the figure of Supay, or beings from the underworld, but, really, there is
not a work that has made a "fabric" with those characteristics that have great similarity, and that
outline the Death, and her attributes as a weaver of destiny, for example. What's more, what do
we know about a deity or deities associated with death, attributes, qualities, related to the fabric
and temporality? In general, studies on the characteristics of a deity have hardly been
developed in this area, we will explain that there really are enough characteristics to speak of
death as a deity, with a series of characteristics that enrich the studies on pre-Hispanic
worldview of ancient Peru
La tribu "Cryptopleureae" ("Delesseriaceae", "Ceramiales", "Rhodophyta") en la Península Ibérica
We present a study of the tribe Cryptopleureae (Delesseriaceae, Ceramiales, Rhodophyta) in the Iberian Peninsula, where it is represented by three species: Acrosorium ciliolatum, Cryptopleura ramosa and Gonimophyllum buffhamii. The most distinctive characteristics of these taxa are described, as well as its morphologic variability, anatomy, cytology, reproductive structures, fenology and distribution.Se presenta un estudio acerca de la tribu Cryptopleureae (Delesseriaceae, Ceramiales, Rhodophyta) en la Península Ibérica, donde se encuentra representada por tres especies: Acrosorium ciliolatum, Cryptopleura ramosa y Gonimophyllum buffhamii. Se describen las características más distintivas de estas especies, variabilidad morfológica, anatomía, citología, estructuras de reproducción, fenología y distribución
Deployment of Digital Video and Audio Over Electrical SCADA Networks
With the arrival of new hardware and software technologies,
supervisory control and data acquisition human-machine
interfaces (SCADA/HMI), usually text-based, can now benefit
from the advantages the inclusion of multimedia information
brings. However, due to the special requirements imposed by
such systems, integrating audio and video data into the SCADA
interfaces is not a trivial task. In this document we analyze those
special characteristics and propose solutions so this integration is
possible in power systems communication.Ministerio de Ciencia y Tecnología TIC2000-0367-P4-0
Power Systems Monitoring and Control using Telecom Network Management Standards
Historically, different solutions have been developed for power systems control and telecommunications network management environments. The former was characterized by proprietary solutions, while the latter has been involved for years in a strong standardization process guided by criteria of openness. Today, power systems control standardization is in progress, but it is at an early stage compared to the telecommunications management area, especially in terms of information modeling. Today, control equipment tends to exhibit more computational power, and communication lines have increased their performance. These trends hint at some conceptual convergence between power systems and telecommunications networks from a management perspective. This convergence leads us to suggest the application of well-established telecommunications management standards for power systems control. This paper shows that this is a real medium-to-long term possibility
An Aphid Effector Targets Trafficking Protein VPS52 in a Host-Specific Manner to Promote Virulence
Plant- and animal-feeding insects secrete saliva inside their hosts, containing effectors, which may promote nutrient release and suppress immunity. Although for plant pathogenic microbes it is well established that effectors target host proteins to modulate host cell processes and promote disease, the host cell targets of herbivorous insects remain elusive. Here, we show that the existing plant pathogenic microbe effector paradigm can be extended to herbivorous insects in that effector-target interactions inside host cells modify critical host processes to promote plant susceptibility. We showed that the effector Mp1 from Myzus persicae associates with the host Vacuolar Protein Sorting Associated Protein52 (VPS52). Using natural variants, we provide a strong link between effector virulence activity and association with VPS52, and show that the association is highly specific to M. persicae-host interactions. Also, coexpression of Mp1, but not Mp1-like variants, specifically with host VPS52s resulted in effector relocalization to vesicle-like structures that associate with prevacuolar compartments. We show that high VPS52 levels negatively impact virulence, and that aphids are able to reduce VPS52 levels during infestation, indicating that VPS52 is an important virulence target. Our work is an important step forward in understanding, at the molecular level, how a major agricultural pest promotes susceptibility during infestation of crop plants. We give evidence that an herbivorous insect employs effectors that interact with host proteins as part of an effective virulence strategy, and that these effectors likely function in a species-specific manner
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