1000 resultados para Action potencial


Relevância:

20.00% 20.00%

Publicador:

Resumo:

El cultivo del almendro tiene un peso importante en la agricultura española con unas 600.000 hectáreas, la mayoría de ellas en secano. Recientemente, la aparición de nuevas variedades y su implantación en regadío, ha permitido un gran salto hacia su reconversión. En el presente artículo se muestran los primeros resultados obtenidos en un ensayo iniciado en enero de 2000 y realizado en Les Borges Blanques (Lleida) con el objetivo de evaluar el potencial productivo de diferentes variedades de almendro en condiciones de riego deficitario (2.500 m3/ha y año). En los primeros años, las seis variedades evaluadas (Ferragnes, Guara, Lauranne, Glorieta, Francolí y Masbovera) han tenido muy buen omportamiento productivo, presentando en el 2006 (7º año) producciones cercanas e incluso superiores a 1.500 kg de grano/ha. Francolí, Lauranne y Glorieta han sido las variedades que han presentado mayor producción acumulada en los 7 primeros años (producciones superiores a 16.000 kg de almendra en cáscara por hectárea). Así mismo, en el artículo se analizan otros aspectos destacados: época de floración, época de recolección, vigor y la facilidad de formación del árbol entre otros.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aquest estudi es centra en l’anàlisi de l’aprofitament d’aigües pluvials en sistemes urbans, concretament al barri de LaPlana - Sta. Bàrbara - Vallpineda de Sitges, en base als escenaris proposats que contemplen diferents criteris i paràmetres. La metodologia utilitzada que conjuga els resultats potencials de l’oferta amb els de la demanda d’aigua al barri permet la determinació del nivell d’autosuficiència hídrica del sistema. Els resultats mostren una alta autosuficiència del 90% en quant es s’apliquen estratègies de gestió hídrica ecoeficients i mesures domèstiques per a reduir la demanda domèstica del sector. A més, la tipologia de coberta inclinada i un major règim pluviomètric anual, s’ha observat afavoreixen l’augment d’aquest índex. Per tant, es considera apropiat realitzar un eficient aprofitament de l’aigua de pluja, com a recurs endogen local, donats els beneficis econòmics, ambientals i socials que comporta en una situació de dèficit hídric com la del municipi de Sitges.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There are controversial reports about the effect of aging on movement preparation, and it is unclear to which extent cognitive and/or motor related cerebral processes may be affected. This study examines the age effects on electro-cortical oscillatory patterns during various motor programming tasks, in order to assess potential differences according to the mode of action selection. Twenty elderly (EP, 60-84 years) and 20 young (YP, 20-29 years) participants with normal cognition underwent 3 pre-cued response tasks (S1-S2 paradigm). S1 carried either complete information on response side (Full; stimulus-driven motor preparation), no information (None; general motor alertness), or required free response side selection (Free; internally-driven motor preparation). Electroencephalogram (EEG) was recorded using 64 surface electrodes. Alpha (8-12 Hz) desynchronization (ERD)/synchronization (ERS) and motor-related amplitude asymmetries (MRAA) were analyzed during the S1-S2 interval. Reaction times (RTs) to S2 were slower in EP than YP, and in None than in the other 2 tasks. There was an Age x Task interaction due to increased RTs in Free compared to Full in EP only. Central bilateral and midline activation (alpha ERD) was smaller in EP than YP in None. In Full just before S2, readiness to move was reflected by posterior midline inhibition (alpha ERS) in both groups. In Free, such inhibition was present only in YP. Moreover, MRAA showed motor activity lateralization in both groups in Full, but only in YP in Free. The results indicate reduced recruitment of motor regions for motor alertness in the elderly. They further show less efficient cerebral processes subtending free selection of movement in elders, suggesting reduced capacity for internally-driven action with age.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"Vegeu el resum a l'inici del document del fitxer adjunt."

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this study the hepatic lipoprotein lipase (LPL), activity was evaluated in adult female mice acclimatized at 5-C and submitted to carbon tetrachloride (CCI) or ethionine, in order to determine the possible role of this enzuyme in the fatty liver. The results were compared with those obtained in mice kept at room temperature (27-C) that the same hepatoesteatosis inducing agent. In contrast to animals kept at room temperature, in cold aclimatized mice neither the enhancement of the LPL-liver activity by the action of CCI or ethionine occurred nor the development of fatty infiltration in the liver was observed. We conclude that the low temperature induced a protective effect against CCI or ethionine-induced fatty liver that was correlated with the no-increase of the hepatic LPL activity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The selectivity of Bacillus thuringiensis toxins is determined both by the toxin structure and by factors inherent to the insect. These toxins contain distinct domains that appear to be functionally important in toxin binding to protein receptors in the midgut of susceptible insects, and the subsequent formation of a pore in the insect midgut epithelium. In this article features necessary for the insecticidal activity of these toxins are discussed. These include toxin structure, toxin processing in the insect midgut, the identification of toxin receptors in susceptible insects, and toxin pore formation in midgut cells. In addition a number of B. thuringiensis toxins act synergistically to exert their full insecticidal activity. This synergistic action is critical not only for expressing the insecticidal activity of these toxins, but could also play a role in delaying the onset of insect resistance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Bacillus sphaericus produces at least two toxins which are highly toxic to mosquito larvae. The binary toxin, which is comprised of proteins of 51.4 and 41.9 kDa, is present in all highly insecticidal strains. The 100 kDa SSII-1 toxin is present in most highly insecticidal as well as the weakly insecticidal strains. The current status of studies on biochemistry and mode of action of these toxins is reviewed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En els darrers 30 anys, els anàlegs de nucleòsids han estat una part essencial de la teràpia antiviral. Més recentment, els anàlegs carbocíclics de nucleòsids s'han convertit en importants objectius pel desenvolupament de nous agents terapèutics antivirals i antitumorals, en tant que l'absència de l'enllaç N-glicosídic els confereix una major estabilitat davant l'acció de les fosforilases. Per altra banda, s'ha descrit que alguns nucleòsids de configuració L presenten, en alguns casos, una bona activitat antiviral, una major estabilitat metabòlica i una toxicitat inferior a la dels seus homòlegs de configuració natural. El present treball planteja la síntesi estereoselectiva de derivats ciclobutènics de L-nucleòsids com a agents terapèutics, susceptibles de presentar una major activitat antiviral i una menor toxicitat que els agents actuals. Per assolir aquest objectiu, s'ha construït l'anell ciclobutènic mitjançant una reacció de fotocicloaddició [2+2]. Al mateix temps, s'ha desenvolupat un estudi de la influència del dissolvent en la reacció de fotocicloaddició [2+2] d'enones a alquens halogenats. A més, s'han estudiat diverses condicions de treball per dur a terme la reacció de deshalogenació dels derivats clorats preparats amb la metodologia anterior, utilitzant Zn com a reductor i amb un sistema d'escalfament per microones com a substituent dels mètodes d'escalfament convencionals. Aquest estudi ha permès disminuir notablement el temps d'aquesta reacció, passant de 7 hores a 20 minuts. Les condicions òptimes d'ambdues reaccions determinades amb aquests estudis han permès preparar l'intermedi clau per a la introducció de les bases nitrogenades, essent aquest un potencial precursor dels anàlegs ciclobutènics de nucleòsids, així com sintetitzar el primer producte de la ruta sintètica dissenyada que presenta la base nitrogenada a la seva estructura.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The three organometallic complexes [(Cis-PtII (DDH) (2,5-Dihidroxibenzensulfonic)2, RhI (CO)2 Cl(2-Aminobenzothiazole) and RhI (CO)2 Cl(5-Cl-2-Methilbenzothiazole)] used in this study had been previously found to have a high in vitro activity against promastigote and amastigote like forms of Leishmania donovani. Here, the cytotoxic effect of these new organometallic complexes on the J-774 macrophages were studied. Only the RhI(CO)2 Cl (2-Aminobenzothiazole) complex induced substantial toxicity in the cells. Also, we assayed the effect of this complex on the parasite's biosynthesis of macromolecules. The RhI(CO)2Cl (5-Cl-2-Methylbenzothiazole) complex inhibited DNA, RNA, and protein synthesis. On the other hand, the two other compounds tested did not inhibit the incorporation of radioactive precursors. Finally important ultrastructural alterations in the parasites treated with the two non-cytotoxic complexes were observed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Multiple sclerosis (MS) is a life-long, potentially debilitating disease of the central nervous system (CNS). MS is considered to be an immune-mediated disease, and the presence of autoreactive peripheral lymphocytes in CNS compartments is believed to be critical in the process of demyelination and tissue damage in MS. Although MS is not currently a curable disease, several disease-modifying therapies (DMTs) are now available, or are in development. These DMTs are all thought to primarily suppress autoimmune activity within the CNS. Each therapy has its own mechanism of action (MoA) and, as a consequence, each has a different efficacy and safety profile. Neurologists can now select therapies on a more individual, patient-tailored basis, with the aim of maximizing potential for long-term efficacy without interruptions in treatment. The MoA and clinical profile of MS therapies are important considerations when making that choice or when switching therapies due to suboptimal disease response. This article therefore reviews the known and putative immunological MoAs alongside a summary of the clinical profile of therapies approved for relapsing forms of MS, and those in late-stage development, based on published data from pivotal randomized, controlled trials.