8,188 research outputs found
Controle biológico de percevejos fitófagos da soja na região de Dourados, MS.
Este trabalho teve como objetivo avaliar o parasitismo natural que ocorre em adultos e em ovos do percevejo-marrom da soja Euschistus heros (Fabricius), bem como multiplicar o parasitóide Telenomus podisi (Ashmead) e liberá-lo em lavouras de soja, visando ao controle biológico do percevejo nesta cultura. Durante a safra 2004/2005 e 2005/2006 e nas entressafras de 2004, 2005 e 2006 foram coletados adultos do percevejo, enquanto nas safras de 2003/2004 e 2004/2005 foram coletadas massas de ovos do inseto durante o período reprodutivo da sojabitstream/item/38732/1/BP200740.pdfDocumento on-line
Entomofauna associada à cultura da mandioca na região sul de Mato Grosso do Sul.
bitstream/item/38729/1/BP200637.pd
Successful reconstruction of whole mitochondrial genomes from ancient Central America and Mexico
The northern and southern peripheries of ancient Mesoamerica are poorly understood. There has been speculation over whether borderland cultures such as Greater Nicoya and Casas Grandes represent Mesoamerican outposts in the Isthmo-Colombian area and the Greater Southwest, respectively. Poor ancient DNA preservation in these regions challenged previous attempts to resolve these questions using conventional genetic techniques. We apply advanced in-solution mitogenome capture and high-throughput sequencing to fourteen dental samples obtained from the Greater Nicoya sites of Jícaro and La Cascabel in northwest Costa Rica (n = 9; A.D. 800–1250) and the Casas Grandes sites of Paquimé and Convento in northwest Mexico (n = 5; A.D. 1200–1450). Full mitogenome reconstruction was successful for three individuals from Jícaro and five individuals from Paquimé and Convento. The three Jícaro individuals belong to haplogroup B2d, a haplogroup found today only among Central American Chibchan-speakers. The five Paquimé and Convento individuals belong to haplogroups C1c1a, C1c5, B2f and B2a which, are found in contemporary populations in North America and Mesoamerica. We report the first successfully reconstructed ancient mitogenomes from Central America, and the first genetic evidence of ancestry affinity of the ancient inhabitants of Greater Nicoya and Casas Grandes with contemporary Isthmo-Columbian and Greater Southwest populations, respectively
La estimulación neonatal por un ambiente nuevo mejora la producción de huevos en gallinas ponedoras
The development of behavioral and endocrine responses to acute stress is greatly influenced by the early postnatal rearing environment. These environmental effects persist throughout life, resulting in stable individual differences in fearfulness. Early stimulation, such as neonatal novelty exposure decreases behavioral reactivity. Previous reports also show that early–life stimulation, such as neonatal exposure to novelty, reduces behavioural reactivity. The aim of this study was to evaluate whether early stimulation increases egg production in adult laying eggs. One–day–old laying hen chicks were exposed to a T–maze (Method A) or a test based on the latency to peck (Method B), and then reared in an industrial poultry farm until adults. A group of non–stimulated hens was used as a control group. Weekly egg production, individual egg weight and weekly feed intake were measured in laying hens under farm conditions for 25 weeks. An increase in egg number was observed in stimulated laying hens by Method A (5.22 ± 0.06, p < 0.01) and by Method B (5.33 ± 0.08, p < 0.001) compared to the controls (4.78 ± 0.24). Likewise, the food conversion index was also greater for stimulated hens by Method A (0.356 ± 0.042; p < 0.05) and Method B (0.363 ± 0.053; p < 0.01), compared to the control group (0.330 ± 0.085). These results indicate that early stimulation could help to improve the adaptation of laying hens in industrial poultry farms.
Key words: chick, early stimulation, egg production, laying hen, stress.El desarrollo de las respuestas comportamentales y endocrinas al estrés agudo está fuertemente influenciado por el entorno postnatal temprano. Estos efectos ambientales
persisten a lo largo de la vida, generando diferencias individuales estables en la temerosidad.
La estimulación temprana, como la exposición a un ambiente nuevo, disminuye la reactividad comportamental. También se demostró en investigaciones previas que una estimulación
temprana en la vida, tal como una exposición neonatal al ambiente nuevo, redujo la reactividad comportamental. El objetivo de este estudio fue evaluar si una estimulación temprana aumenta la producción de huevos en gallinas adultas. Pollitos de gallinas ponedoras de un día de edad se expusieron a un laberinto en T (método A) o una prueba basada en la latencia para picotear un objeto (método B), posteriormente se trasladaron a una granja avícola hasta
la edad adulta. Se designó a un grupo de gallinas como control, las cuales no se estimularon por ninguno de los métodos anteriormente nombrados. Durante 25 semanas se registró la postura semanal de huevos, el peso individual de los huevos y el consumo de alimento semanal en las gallinas ponedoras criadas bajo condiciones de granja. Se observó un aumento en el número de huevos en las gallinas estimuladas por el método A (5,22 ± 0,06, p < 0,01) y por el método B (5,33 ± 0,08, p < 0,001) comparadas a los controles no estimulados (4,78 ± 0,24).
Del mismo modo, el índice de conversión alimenticia también fue mayor para las gallinas estimuladas por el método A (0,356 ± 0,042, p < 0,05) y el método B (0,363 ± 0,053, p < 0,01) respecto al grupo control (0,330 ± 0,085). Estos resultados indican que la estimulación temprana puede ayudar a mejorar la adaptación de gallinas ponedoras a las condiciones de cría intensiva en las granjas avícolas industriales.
Palabras clave: pollito, estimulación temprana, producción de huevos, gallinas ponedoras, estrés
Procedure Manual for the Pneumology Department of an Argentine university hospital
Introducción La redacción de un manual de procedimientos (MP) obliga a racionalizar la actividad diaria, permite hallar imperfecciones, discutir e implementar medidas preventivas y correctivas, y acorta la brecha entre teoría y práctica. Nuestro objetivo es describir las etapas que llevaron a su redacción para un Servicio de Neumonología en un hospital universitario de gestión pública, detallar su estructura y relatar dificultades y perspectivas.
Material y métodos Se determinó el organigrama y se establecieron interrelaciones y competencias. Se asignó la redacción de procedimientos según competencia de cada profesional en base a bibliografía, regulaciones, normas de acreditación y experiencia institucional. Los procedimientos fueron vinculados mediante hipertexto y cargados en la red informática.
Resultados Ocupa 300 páginas, en 3 secciones: Procedimientos Administrativos, Operativos y de Seguridad, y un anexo. Consta de 57 procedimientos (48 de confección propia, 9 tomados de sociedades científicas). Para estudios específicos que se realizan en el Laboratorio se redactaron procedimientos de novo. Cuando se hallaron disponibles, se utilizaron procedimientos previos, especialmente aquellos referidos a bioseguridad y seguridad ambiental. Discusión: Se dedicó toda una sección a detallar diversas acciones administrativas de uso habitual, detectadas como fuente de conflicto. Dado que cada institución tiene su idiosincrasia administrativa y operativa, creemos que los textos y recomendaciones de sociedades científicas deben ser adaptados y/o modificados para expresar la práctica habitual en cada Servicio. Conclusiones: La información recabada dará lugar a futuras actualizaciones. Esto debe culminar en una mejor atención del paciente, fin último de nuestra Institución.Introduction The writing of a procedure manual (PM) requires streamlining daily activities, allowing to find imperfections, discuss and implement preventive and corrective measures, and decreases the gap between theory and practice. We describe the stages that led to the drafting of a PM for a Pneumology Department at a public university hospital, detailing its structure and reporting problems and prospects.
Methods We determined an organization flow chart and established interrelations and personnel skills. The drafting of procedures was assigned according to competence of each staff member, based on literature, regulations, accreditation standards and institutional experience. The procedures were linked by hypertext and loaded into our computer network.
Results: It extend over 300 pages in 3 sections: Administrative, Operational and Safety Procedures, and an appendix . It consists of 57 procedures (48 of these are own, while 9 were drawn from scientific societies). Some procedures for specific studies that are performed in our laboratory were written de novo. When available, previous procedures were used, especially those related to biosafety and environmental safety. Discussion: An entire section is devoted to a number of commonly used administrative actions, identified as source for conflict. As each institution has its own administrative and operational idiosyncrasies, we believe that recommendations of scientific societies should not be used verbatim, but must be adapted and/or modified to the usual practice in each department. Conclusions: The gathered information will lead to future updates. All this must lead to better patient care, ultimate goal of our InstitutionFil: Arce, S. C.. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Civale, S. N.. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Rodriguez, M. N.. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: de Vito, Eduardo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin
Critical Comparison between Modified Monier-Williams and Electrochemical Methods to Determine Sulfite in Aqueous Solutions
In the present work, known concentration of sulfite aqueous solutions in the presence and absence of gallic acid was measured to corroborate the validity of modified Monier-Williams method. Free and bound-sulfite was estimated by differential pulse voltammetry. To our surprise, the modified Monier-Williams method (also known as aspiration method) showed to be very inaccurate for free-sulfite, although suitable for bound-sulfite determination. The differential pulse approach, using the standard addition method and a correction coefficient, proved to be swift, cheap, and very precise and accurate
Local electroexfoliation of graphene with a STM tip
Graphite surfaces can be manipulated by several methods to create graphene structures of different shapes and sizes. Scanning tunneling microscopy (STM) can be used to create these structures either through mechanical contact between the tip and the surface or through electro-exfoliation. In the latter, the mechanisms involved in the process of exfoliation with an applied voltage are not fully understood. Here we show how a graphite surface can be locally exfoliated in a systematic manner by applying an electrostatic force with a STM tip at the edge of a terrace, forming triangular flakes several nanometers in length. We demonstrate, through experiments and simulations, how these flakes are created by a two-step process: first a voltage ramp must be applied at the edge of the terrace, and then the tip must be scanned perpendicularly to the edge. Ab-initio electrostatic calculations reveal that the presence of charges on the graphite surface weakens the interaction between layers allowing for exfoliation at voltages in the same range as those used experimentally. Molecular dynamics simulations show that a force applied locally on the edge of a step produces triangular flakes such as those observed under STM. Our results provide new insights towards surface modification that can be extended to other layered materials
ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow: Structure, Entrainment and Core Impact
We present ALMA Cycle 1 observations of the HH46/47 molecular outflow using
combined 12m array and ACA observations. The improved angular resolution and
sensitivity of our multi-line maps reveal structures that help us study the
entrainment process in much more detail and allow us to obtain more precise
estimates of outflow properties than previous observations. We use 13CO(1-0)
and C18O(1-0) emission to correct for the 12CO(1-0) optical depth to accurately
estimate the outflow mass, momentum and kinetic energy. This correction
increases the estimates of the mass, momentum and kinetic energy by factors of
about 9, 5 and 2, respectively, with respect to estimates assuming optically
thin emission. The new 13CO and C18O data also allow us to trace denser and
slower outflow material than that traced by the 12CO maps, and they reveal an
outflow cavity wall at very low velocities (as low as 0.2km/s with respect to
the cores central velocity). Adding with the slower material traced only by
13CO and C18O, there is another factor of 3 increase in the mass estimate and
50% increase in the momentum estimate. The estimated outflow properties
indicate that the outflow is capable of dispersing the parent core within the
typical lifetime of the embedded phase of a low-mass protostar, and that it is
responsible for a core-to-star efficiency of 1/4 to 1/3. We find that the
outflow cavity wall is composed of multiple shells associated with a series of
jet bow-shock events. Within about 3000AU of the protostar the 13CO and C18O
emission trace a circumstellar envelope with both rotation and infall motions,
which we compare with a simple analytic model. The CS(2-1) emission reveals
tentative evidence of a slowly-moving rotating outflow, which we suggest is
entrained not only poloidally but also toroidally by a disk wind that is
launched from relatively large radii from the source.Comment: Accepted for publication in ApJ. 26 pages, 20 figure
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