Germinación de conidios de Botryosphaeria dothidea Mough.: Fr (Ces. & De Not.) y alteraciones histológicas en tallos de pitahaya (Hylocereus undatus) (Haworth) Britton & Rose

Conidial germination of Botryosphaeria dothidea (anamorph: Fusicoccum) in sterile distilled water and 1% sterile dextrose solution was evaluated at 4, 6, 12, 24 and 36 h after incubation. Also, it was described the anatomical changes on pitahaya stems induced by this fungus, collected in the field and artificially inoculated in the laboratory. Conidial germination was less than 30% in water and it was improved when 1% dextrose was added to the water. In 1% dextrose solution the germination was 90% after 4h of incubation and 100% at 6 h. Pathogen germ tubes had entered through wounds and sometimes through stomata and hyphae colonized intra and intercellularly in the parenchyma-chlorenchyma tissues. On naturally and artificially diseased stems the main alterations were: destruction of cuticle, hyperplasia of epidermal and collenchymatous hypodermal cells and conform the advance of the pathogen a layer of lignified periderm was formed surrounding the damaged tissues; however, it couldn't stop the advance of the pathogen and the cells that surrounded the lesion suffered necrosis.Se evaluó la germinación de conidios de Botryosphaeria dothidea (anamorfo: Fusicoccum) en agua destilada estéril y en una solución de dextrosa 1% a las 4, 6, 12, 24 y 36 h de incubación. También, se describieron los cambios anatómicos en tallos de pitahaya inducidos por este hongo, tanto aquellos naturalmente infectados en campo como inoculados artificialmente en laboratorio. La germinación de conidios en agua estéril solo alcanzó el 30%, mientras que la adición de dextrosa al 1% mejoró la germinación. En una solución de dextrosa al 1% la germinación a las 4 h fue de 90% y del 100% a las 6 h. Los tubos germinativos del hongo penetraron a través de las heridas y algunas veces a través de los estomas y se multiplicaron inter e intracelularmente en los tejidos del parénquima-clorénquima. En tallos enfermos natural y artificialmente, las principales alteraciones fueron: destrucción de la cutícula, hiperplasia de las células epidermales e hipodermales colenquimatosas. Conforme el avance del patógeno se formó una capa de peridermis lignificada que rodeó el tejido dañado; sin embargo, no se detuvo el avance del patógeno y las células que rodeaban la lesión se necrosaron.Fil: Valencia-Botín, Alberto J.. Universidad de Guadalajara (México)Fil: Cisneros-López, María E..Fil: Ruíz-Sánchez, Esaú. Instituto Tecnológico de Conkal (México

Germinación de conidios de Botryosphaeria dothidea Mough.: Fr (Ces. & De Not.) y alteraciones histológicas en tallos de pitahaya (Hylocereus undatus) (Haworth) Britton & Rose

Conidial germination of Botryosphaeria dothidea (anamorph: Fusicoccum) in sterile distilled water and 1% sterile dextrose solutionwas evaluated at 4, 6, 12, 24 and 36 h after incubation. Also, it was described the anatomical changes on pitahaya stems induced by this fungus, collected in the field and artificially inoculated in the laboratory. Conidial germination was less than 30% in water and it was improved when 1% dextrose was added to the water. In 1% dextrose solution the germination was 90% after 4h of incubation and 100% at 6 h. Pathogen germ tubes had entered through wounds and sometimes through stomata and hyphae colonized intra and intercellularly in the parenchyma-chlorenchyma tissues. On naturally and artificially diseased stems the main alterations were: destruction of cuticle, hyperplasia of epidermal and collenchymatous hypodermal cells and conform the advance of the pathogen a layer of lignified periderm was formed surrounding the damaged tissues; however, it couldn't stop the advance of the pathogen and the cells that surrounded the lesion suffered necrosis.Conidial germination of Botryosphaeria dothidea (anamorph: Fusicoccum) in sterile distilled water and 1% sterile dextrose solutionwas evaluated at 4, 6, 12, 24 and 36 h after incubation. Also, it was described the anatomical changes on pitahaya stems induced by this fungus, collected in the field and artificially inoculated in the laboratory. Conidial germination was less than 30% in water and it was improved when 1% dextrose was added to the water. In 1% dextrose solution the germination was 90% after 4h of incubation and 100% at 6 h. Pathogen germ tubes had entered through wounds and sometimes through stomata and hyphae colonized intra and intercellularly in the parenchyma-chlorenchyma tissues. On naturally and artificially diseased stems the main alterations were: destruction of cuticle, hyperplasia of epidermal and collenchymatous hypodermal cells and conform the advance of the pathogen a layer of lignified periderm was formed surrounding the damaged tissues; however, it couldn't stop the advance of the pathogen and the cells that surrounded the lesion suffered necrosis

Especies de caza: procesos de extinción ocultos tras elevados tamaños de censo

Management of game species may involve a risk of alteration of their genetic properties. Local adaptations may be disrupted if artificially selected individuals from farms or those belonging to distant geographical areas are introduced to increase population density or trophy “quality”. In Spain, red deer (Cervus elaphus) from different European subspecies have been introduced to increase the size of trophies (antlers) of local populations. Legislation against these introductions is not effective for various reasons, and once the individuals are in the Iberian peninsula it is virtually impossible to prevent their spreading throughout the whole territory without a genetic tool to distinguish between autochthonous and foreign specimens. We have developed such a genetic test and propose a strategy to dissuade land–owners from importing foreign deer. Since deer are bred mainly for their antlers, our strategy is based on an agreement with the National Trophy Body in Spain which rejects trophies from foreign populations. Rejection decreases the value of the trophy so that it becomes more profitable to produce autochthonous deer. Using such a strategy at some critical step in the production or commercialization process may be a good model to apply in protecting genetic properties of exploited species.La gestión de las especies de caza puede conllevar riesgos de alteración de sus propiedades genéticas. Las adaptaciones locales pueden deteriorarse si ejemplares producidos mediante selección artificial en granjas o procedentes de áreas geográficas distantes, son introducidos para aumentar la densidad poblacional o la "calidad" de los trofeos de caza. En España, se han introducido ejemplares de ciervo ibérico (Cervus elaphus) procedentes de distintas subespecies europeas para aumentar así el tamaño de las cuernas (trofeos de caza) de las poblaciones autóctonas. La legislación contra este tipo de introducciones no es eficaz por diversos motivos y, una vez introducidos los ejemplares en la península ibérica, es prácticamente imposible prevenir su dispersión por todo el territorio sin contar con herramientas genéticas que permitan diferenciar los ejemplares autóctonos de los foráneos. Nosotros hemos desarrollado un test genético para este fin, y hemos propuesto una estrategia para disuadir a lospropietarios de llevar a cabo la importación de ejemplares foráneos. Puesto que los ciervos se crían fundamentalmente por su cornamenta como trofeo de caza, nuestra estrategia se ha basado en un acuerdo con la Junta Nacional de Homologación de Trofeos de Caza, para que ésta rechace los trofeos pertenecientes a ejemplares foráneos. Este rechazo reduce el valor de los ejemplares procedentes de otras poblaciones y favorece la producción de ciervo autóctono. Sugerimos que la utilización de estrategias de este tipo en puntos clave de procesos de producción o comercialización, puede ser un buen modelo a aplicar para proteger las propiedades genéticas de las especies sujetas a explotación por el hombre

Game species: extinction hidden by census numbers

Management of game species may involve a risk of alteration of their genetic properties. Local adaptations may be disrupted if artificially selected individuals from farms or those belonging to distant geographical areas are introduced to increase population density or trophy ‘quality’. In Spain, red deer (Cervus elaphus) from different European subspecies have been introduced to increase the size of trophies (antlers) of local populations. Legislation against these introductions is not effective for various reasons, and once the individuals are in the Iberian peninsula it is virtually impossible to prevent their spreading throughout the whole territory without a genetic tool to distinguish between autochthonous and foreign specimens. We have developed such a genetic test and propose a strategy to dissuade land-owners from importing foreign deer. Since deer are bred mainly for their antlers, our strategy is based on an agreement with the National Trophy Body in Spain which rejects trophies from foreign populations. Rejection decreases the value of the trophy so that it becomes more profitable to produce autochthonous deer. Using such a strategy at some critical step in the production or commercialisation process may be a good model to apply in protecting genetic properties of exploited species

Carnot, Stirling, Ericsson stochastic heat engines: Efficiency at maximum power

This work obtains the efficiency at maximum power for a stochastic heat engine performing Carnot-like, Stirling-like and Ericsson-like cycles. For the mesoscopic engine a Brownian particle trapped by an optical tweezers is considered. The dynamics of this stochastic engine is described as an overdamped Langevin equation with a harmonic potential, whereas is in contact with two thermal baths at different temperatures, namely, hot ($T_h$) and cold ($T_c$). The harmonic oscillator Langevin equation is transformed into a macroscopic equation associated with the mean value $\langle x^2(t)\rangle$ using the original Langevin approach. At equilibrium stationary state this quantity satisfies a state-like equation from which the thermodynamic properties are calculated. To obtained the efficiency at maximum power it is considered the finite-time cycle processes under the framework of low dissipation approach.Comment: 2 3pages, 5 figure

Assessment of DNA Damage by Comet Assay in Buccal Epithelial Cells: Problems, Achievement, Perspectives

DNA damage risk assessment in comet assay by the use of buccal mucosa cells has great advantages in comparison with other cell type sample due to more safely, easier, cheaper, and non-invasive method for in vivo studies. According to the OECD Guidelines, the in vivo mammalian alkaline comet assay is well-established and validated method for measuring DNA strand breaks in single eukaryotic cells. Considering exposure to xenobiotics and endogenous damage inductors, buccal mucosa cells are the first to be in direct contact after exposure and this makes them an ideal biomatrices in evaluation of the level of individual genotoxicity to several compounds already mentioned. Their clinical diagnostic applicability confers a potential use in patients across time. However, the number of publications referring to the human buccal comet assay is low in the last two decades. This low growing interest may be explained by several factors, including its relative technical problems. Different procedures have been used in collecting and processing the samples. In order to have widespread acceptance and credibility in human population studies, the comet assay in buccal cells requires standardization of the protocol, of parameters analyzed, and a better knowledge of critical features affecting the assay outcomes, including the definition of the values of spontaneous DNA damage. There is a need for further collaborative work as in the HUMN (micronucleus assay on lymphocytes) and HUMNxL (micronucleus assay on buccal cells) collaborative projects. The creation of a network of laboratories will allow more focused validation studies, including the design of a classic, historic, prospective cohort study in order to explore the link between measures of genetic instability in the buccal mucosa and the risk of cancer and other chronic-degenerative diseases. One such network connection will start in 2016 as a COST project under the name “hCOMET—The comet assay as a human biomonitoring tool” launched by Prof. Andrew Collins

Ferrimagnetic nanostructures for magnetic memory bits

Increasing the magnetic data recording density requires reducing the size of the individual memory elements of a recording layer as well as employing magnetic materials with temperature-dependent functionalities. Therefore, it is predicted that the near future of magnetic data storage technology involves a combination of energy-assisted recording on nanometer-scale magnetic media. We present the potential of heat-assisted magnetic recording on a patterned sample; a ferrimagnetic alloy composed of a rare earth and a transition metal, DyCo$_5$, which is grown on a hexagonal-ordered nanohole array membrane. The magnetization of the antidot array sample is out-of-plane oriented at room temperature and rotates towards in-plane upon heating above its spin-reorientation temperature (T$_R$) of ~350 K, just above room temperature. Upon cooling back to room temperature (below T$_R$), we observe a well-defined and unexpected in-plane magnetic domain configuration modulating with ~45 nm. We discuss the underlying mechanisms giving rise to this behavior by comparing the magnetic properties of the patterned sample with the ones of its extended thin film counterpart. Our results pave the way for novel applications of ferrimagnetic antidot arrays of superior functionality in magnetic nano-devices near room temperature.Comment: 19 pages, 4 figure

Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule

It has been suggested that a sub-population of orexinergic neurones whose somata lie in the lateral hypothalamic area (LHA) play an important role in regulating the reinforcing value of both food and drugs. This experiment examined the effect of disruption of orexinergic mechanisms in the LHA on performance on the progressive-ratio schedule of reinforcement, in which the response requirement increases progressively for successive reinforcers. The data were analysed using a mathematical model which yields a quantitative index of reinforcer value and dissociates effects of interventions on motor and motivational processes (Killeen, 1994). Rats were trained under a progressive-ratio schedule using food-pellet reinforcement. They received bilateral injections of conjugated orexin-B-saporin (OxSap) into the LHA or sham lesions. Training continued for a further 40 sessions after surgery. Equations were fitted to the response rate data from each rat, and the parameters of the model were derived for successive blocks of 10 sessions. The OxSap lesion reduced the number of orexin-containing neurones in the LHA by approximately 50% compared to the sham-lesioned group. The parameter expressing the incentive value of the reinforcer was not significantly altered by the lesion. However, the parameter related to the maximum response rate was significantly affected, suggesting that that motor capacity was diminished in the OxSap-lesioned group. The results indicate that OxSap lesions of the LHA disrupted food-reinforced responding on the progressive-ratio schedule. It is suggested that this disruption was brought about by a change in non-motivational (motor) processes

Mejoramiento del Sistema de Acueducto en el Distrito de Buenaventura

Este proyecto para el sistema de acueducto de Buenaventura abarcó todos los componentes del sistema, por considerar que en cada uno de ellos hay oportunidades importantes de reducción del agua que se pierde en el sistema, o cuyo uso no es eficiente. Las acciones se circunscribieron a aquellas áreas abastecidas por el sistema, o sea el perímetro urbano y los corregimientos de Córdoba, San Cipriano, Citronela y La Gloria. Este programa se enfocó a optimizar, el recurso hídrico y hacer un uso sostenible del mismo, mediante la identificación y caracterización de aquellos eventos que por su naturaleza producen efectos negativos sobre el medio y por tanto establecer medidas de control y mitigación adecuadas.This project for the Buenaventura aqueduct system covered all the components of the system, considering that in each one of them there are important opportunities to reduce the water that is lost in the system, or whose use is not efficient. The actions were limited to those areas supplied by the system, that is, the urban perimeter and the corregimientos of Córdoba, San Cipriano, Citronela and La Gloria. This program focused on optimizing water resources and making sustainable use of them, through the identification and characterization of those events that by their nature produce negative effects on the environment and therefore establish adequate control and mitigation measures