783 research outputs found
Common cellular events occur during wound healing and organ regeneration in the sea cucumber Holothuria glaberrima
<p>Abstract</p> <p>Background</p> <p>All animals possess some type of tissue repair mechanism. In some species, the capacity to repair tissues is limited to the healing of wounds. Other species, such as echinoderms, posses a striking repair capability that can include the replacement of entire organs. It has been reported that some mechanisms, namely extracellular matrix remodeling, appear to occur in most repair processes. However, it remains unclear to what extent the process of organ regeneration, particularly in animals where loss and regeneration of complex structures is a programmed natural event, is similar to wound healing. We have now used the sea cucumber <it>Holothuria glaberrima </it>to address this question.</p> <p>Results</p> <p>Animals were lesioned by making a 3–5 mm transverse incision between one of the longitudinal muscle pairs along the bodywall. Lesioned tissues included muscle, nerve, water canal and dermis. Animals were allowed to heal for up to four weeks (2, 6, 12, 20, and 28 days post-injury) before sacrificed. Tissues were sectioned in a cryostat and changes in cellular and tissue elements during repair were evaluated using classical dyes, immmuohistochemistry and phalloidin labeling. In addition, the temporal and spatial distribution of cell proliferation in the animals was assayed using BrdU incorporation. We found that cellular events associated with wound healing in <it>H. glaberrima </it>correspond to those previously shown to occur during intestinal regeneration. These include: (1) an increase in the number of spherule-containing cells, (2) remodeling of the extracellular matrix, (3) formation of spindle-like structures that signal dedifferentiation of muscle cells in the area flanking the lesion site and (4) intense cellular division occurring mainly in the coelomic epithelium after the first week of regeneration.</p> <p>Conclusion</p> <p>Our data indicate that <it>H. glaberrima </it>employs analogous cellular mechanisms during wound healing and organ regeneration. Thus, it is possible that regenerative limitations in some organisms are due either to the absence of particular mechanisms associated with repair or the inability of activating the repair process in some tissues or stages.</p
A note on the combustion of blends of diesel and soya, sunflower and rapeseed vegetable oils in a light boiler
Producción CientíficaThis paper deals with the study of the vegetable oils (VO) used as fuel for heating. The properties of sunflower, rape and soya oils are studied and these are compared with the properties of C-diesel fuel (used for heating domestic purposes in Spain). The mixtures of VO and diesel are studied and characterized and, finally, the results of a series of combustion trials of the mixtures in a conventional heating installation with a mechanical pulverization burner are presented. The results show that viscosity of VO limits the use of blends up to 40% of them, and the oxygen present in their structures contributes to an efficiency gai
Características del emplazamiento, Petrología y Geoquímica de Espessartitas en el Plutón de la Maladeta: estudio preliminar
[Resumen] Los diques de lamprófidos espessartíticos son frecuentes en el plutón circunscrito de La Maladeta (Pirineos Centrales, Huesca-Lérida). Su emplazamiento, se produjo bajo unas condiciones confinadas y con un control estructural, afectando a todos los litotipos plutónicos (Cuarzo-Gabros, Granodioritas, Tonalitas y Sienogranitos) y, también a las etapas filonianas ácidas (Aplita y Pegmatitas). La composición mineral (con destacado contenido en anfíboles de composición hornblenda pargasítica) y la Geoquímica, definen una afinidad calco-alcalina cuya signatura en elementos mayores y trazas, es bastante análoga a la óbtenida en lamprófidos similares, emplazados en macizos granodioríticos. Esta afinidad presenta una relación genética con la granodiorita, como término volumétricamente más representativo del Macizo.[Abstract] Lamprophyric dykes (Spessartites) are frequent in the Maladeta circumscribe plutonic massif (Central Pyrenees, Huesca-Lérida). The setting of these dykes, under confinant strains and with a structural control, affected to á1l the plutonic rocktypes (Quanz-Gabbros, Granodiorites, Tonalites and Syenogranites) and to the acid dykes (Aplites and Pegmatites) too. The mineral (with high contents in Pargasitic-Hornblende amphiboles) and geochemical
compositions, define a calc-alkaline affinity, very similar (Major and trace elements) to that of analogue lan prophyres, set in Granodioritic massifs. This affinity shows a genetic relation with the Granodiorite, as volumetrically most representative rock-type in the massif
Combustion of Soya Oil and Diesel Oil Mixtures for Use in Thermal Energy Production
Producción CientíficaIn August 2005, Spain approved the Plan for Renewable Energy Sources for the period 2005-2010 (P.E.R.), including co-combustion installations. Co-combustion in the P.E.R. aims to increase power output by 12,185.3 GWh in five years and shows great interest in studies of the combustion of mixtures of fossil and bio-combustible fuels.
This paper presents studies of the co-combustion of soya oil and diesel for thermal heating. The paper begins with a characterization of soya oil as well as mixtures of this oil, with diesel, as fuels. The combustion of the soya oil mixtures and diesel is made in an installation, where the pressure of injection as well as the air volume of the burner can be changed. The obtained results inside to be the environmental average legislation and a greater efficiency of combustion is found. The conclusions show that the use of mixtures of soya oil and Diesel for producing thermal energy in conventional equipment is feasible
Petrology of the Maladeta granitoids ln the Tahüll-Lago Negro sector (Lérida)
[Resumen] El Macizo plutónico de La Maladeta (Huesca-Lérida) corresponde, en su sector central (Tahül1-lago Negro), a un plutón circunscrito, cuyo carácter polifásico, está representado por los cuatro pulsos siguientes: a) los Cuarzo-Gabros, ubicados en su extremo sur, b) las Granodioritas que, con contenidos variables en anfíbol y biotita, comprenden, en conjunto, el volumen dominante y el pulso más representativo, c) las tonalitas con alto contenido en biotita y, por último, d) los sienogranitos (de dos micas) situados en su zona más central. La composición modal y, en especial, el análisis químico de las fases minerales principales (piroxeno, anfíbol, plagioclasa, biotita, moscovita y feldespato) corroboran una evolución magmática gradual, desde las composiciones más indiferenciadas (Cuarzo-Gabros) hasta las más tardías (Sienogranitos). Se observa una buena correspondencia entre la evolución petrologica (a nivel espacia!) y la de composición mineral, obtenidas por nosotros, con la secuencia de edades radiométicas (Rb/ Sr y U/Pb) determinadas por MICHARD-VITRAC, A. el al, (1980). Esta zonación tiene, a su vez, una muy buena correspondencia con las pautas de evolución geoquímica (elementos mayores y trazas) obtenidas en estudios preliminares (ARRANZ, E., 1991; ARRANZ, E. el al., 1991 a, by c).[Abstract] The Maladeta plutonic Massif (Huesca-Lérida) corresponds, in its central area (Tahül1-Lago Negro), to a circumscribed pluton wich, with multiepisodic character, is represented by the fol1owing four pulses: a) the Quartz-Gabbros, located in its southern extreme brim, b) the Granodiorites that, with variable amount in amphibole and biotite, consist, as a whole, the dominant volume and the most representative pulse, c) the biotite-rich Tonalites and, lastly, d) the syenogranites (with two micas), located in its centermost point. The modal composition and, special1y, the chemical analysis in main mineral phases (pyroxene, amphibole, plagioclase, biotite, muscovite, and feldspar), confirm a gradual magmatic evolution, from' a more indifferentiate composition (Quartz-Gabbross) to the latest (Syenogranites). There exists a good correspondence between the petrological and mineralogical composition, obtained by us, with the sequence of radiometric dates (Rb/Sr and
U/Pb) analysed by MICHARD-VITRAC el al., (1980). The petrological zonation has, in turn, a very good correspondence with the pattern of magmatic evolution (major and trace elements) obtained in preliminary studies (ARRANZ, E., 1991; ARRANZ, E. el al., 1991 a, b y c)
Composition and barometric implications of the amphiboles from the Maladeta plutonic complex (Central Pyrenees, Huesca-Lérida)
[Abstract] The composition of the amphiboles in basic rocks (gabbros and diorites), granodiorites, monzogranites with minor amphibole and mafic microgranular enclaves from the Maladetta massif, corresponds to calcic terms (magnesioHornblende, actinolitic hornblende and actinolite), with reduced values ofAl tot• The main substitutional types are edenite, pargasite and Ti-Tschermakite, with other minor types, generating compositions with an AIIV excess. The application of three of the proposed calibrations for the Altot in Horblende geobarometer, gives anomalously low pressure values for the cristallyzation of the plutonic rock-types, suggesting that the amphibole crystals were formed below 2 Kbar of pressure, and in a continous way to subsolidus conditions,probably at the same time as AI-saturating phases formed
Doctorado de Santa Teresa de Jesús y de San Juan de La Cruz
Escritos respectivamente premiados, el primero en el Certamen Literario celebrado en Avila, en octubre de 1894 ; y el último en el celebrado en Segovia en noviembre de 1891, con ocasión del Tercer Centenario del extático doctor.Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 201
Consensus recommendations on sleeping problems in Phelan-McDermid syndrome
Early onset sleep problems and disorders are very common in individuals with Phelan-McDermid Syndrome (PMS) with rates of up to 90%. These sleep problems and disorders cannot be taken lightly. Not only do they have a major impact on the health, behaviour, functioning and learning opportunities of affected individuals, they can also have detrimental effects on the well-being and resilience of parents and caregivers, ultimately affecting the physical health, mental health and well-being of the whole social system. In this review we aim to understand the types and frequencies of sleeping problems in PMS as the basis for recommendations on their management and treatment and to provide general guidelines for clinicians and practitioners. We conducted an in-depth literature search, summarised findings, and participated in a series of consensus meetings with other consortium members - experts on PMS and stakeholders - to agree on guidelines and recommendations. In parallel, a world-wide survey was created and distributed amongst parents to include their perspective. Our literature search found only four articles specifically focused on sleeping problems in PMS, although some other articles mentioned prevalence and associated factors. Country-specific prevalence rates ranged between 24% and 46%, whereas our parental survey reported 59%. The main problems reported involved difficulty falling asleep and numerous night awakenings, with being restless in sleep, night-time incontinence, and tooth grinding also commonly reported. Only a small number of individuals had undergone a sleep study monitored by a specialist. Bedtime resistance normally decreases with age, but sleep-onset delay, sleep anxiety, parasomnias, problems falling and remaining asleep remain throughout lifespan, with total sleep time improving during adulthood. However, this improvement was also accompanied by a substantial increase in parasomnias. Ultimately, an increase in sleep disorders in children correlates with increased sleep disorders and daytime sleepiness in parents/caregivers. No study to date has focused on the underlying causes of sleeping problems in PMS, but comorbid mental health conditions, somatic causes, or (poly)pharmacy have been proposed as triggers for sleeping disturbances. Currently there is no PMS-specific treatment for sleeping problems, and current recommendations are mostly based on individuals with intellectual disability and/or neurodevelopmental conditions.</p
Las doleritas toleiticas triasicas del sector SE de la Cordillera Ibérica : Petrología y Geoquímica
Las doleritas toleíticas aflorantes en diapiros triásicos del SE de la Cordillera Ibérica
(Alfarp, Quesa y Lugar Nuevo de Fenollet, SE de Valencia) representan líquidos diferenciados
(valores bajos en Ni, Cr y mg*) emplazados como sills, de escaso espesor, por
debajo de sedimentos (arcillas, margas y yesos), poco consolidados, del límite Triásico
superior-Hettangiense. Su composición mineral y geoquímica, con afinidad toleítica continental
y similitud a MORB, evidencia el carácter menos diferenciado de las doleritas de
Alfarp, respecto a las de Quesa, siendo las doleritas aflorantes en Fenollet las que presentan
una composición más evolucionada. Estas doleritas son la expresión de un
magmatismo poco profundo, asociado al inicio del rifting mesozoico, desarrollado en la
zona de intersección del rift celtibérico y el borde NE del surco bético. Este magmatismo
presenta claras diferencias respecto a las doleritas toleíticas, menos diferenciadas, de los
dominios pirenaico y bético.The tholeiitic dolerites that crop out in three diapirs of the SE of the Iberian Chain
(Alfarp, Quesa and Lugar Nuevo de Fenollet, Valencia), are the expression of evolved
(iow Ni, Cr and mg* values) basic magmas, injected into poorly lithified sediments (iutites,
marls and gypsum) which represent the Upper Triassic (Keuper facies)-Hettangian
boundary, developing sills with reduced thickness. Their mineral and whole-rock geochemical
compositions indicate a continental tholeiitic affinity and certain similarities to
a MORB composition and, on the other hand, show that the Alfarp dolerites represent
the less evolved compositions, whereas the Fenollet dolerites show a significantly greater
differentiation. These rocks are the expression of a shallow magmatism, related to the
initial stages of the mesozoic rifting that affected the intersection of the Celtiberian Rift
with the Betic Graben. This magmatism is clearly different of the isochronous tholeiitic
magmatism (dolerites) which crops out at the Pyrenees and [email protected]
SIMULACIÓN CLIMÁTICA DE INVERNADEROS EN DIFERENTES REGIONES DE PORTUGAL: ESTIMACIÓN DE INDICADORES DE VIABILIDAD ENERGÉTICA Y ECONÓMICA
En el presente trabajo se muestran los resultados de un estudio de viabilidad técnica y económica de la instalación de un invernadero calefactado en seis zonas de Portugal (Dois Portos, Faro, Marinha Grande, Ponta Delgada, Porto y Zambujeira). Se tomaron como referencia tres cultivos con distintos requerimientos energéticos (tomate, fresa y lechuga). En todos los casos analizados se empleó un invernadero multitúnel con generadores de aire caliente como calefacción, considerando como alternativas de combustible gasoil y gas natural. Para la realización del trabajo se utilizó el Simulador Climático de Invernaderos (SCI). Las conclusiones extraídas muestran que en tomate y fresa no resulta rentable instalar un sistema de calefacción en invernadero, en ninguno de los emplazamientos seleccionados. Únicamente en el cultivo de fresa lo es si se utiliza gas natural como combustible, en Ponta Delgada San Miguel si aumentase el precio de venta de la producción en más de un 50 %. En el cultivo de lechuga, en las localidades que es rentable, el período de retorno de la inversión es inferior a 2 años. Esto ocurre, en el caso de usar como combustible gasoil en Faro, Ponta Delgada y Zambujeira, y usando gas natural en Dois Portos, Faro, Ponta Delgada, Porto y Zambujeira
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