954 research outputs found

    Diffraction and an infrared finite gluon propagator

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    We discuss some phenomenological applications of an infrared finite gluon propagator characterized by a dynamically generated gluon mass. In particular we compute the effect of the dynamical gluon mass on pppp and pˉp{\bar{p}}p diffractive scattering. We also show how the data on γp\gamma p photoproduction and hadronic γγ\gamma \gamma reactions can be derived from the pppp and pˉp\bar{p}p forward scattering amplitudes by assuming vector meson dominance and the additive quark model.Comment: 4 pages, 7 figures, added references and figures, changed structure. Contribution to Proceedings of XVIIIth Reuniao de Trabalho sobre Interacoes Hadronicas, Sao Paulo, Brazil, 22-24 May, 200

    Evaluation degree of degraded rangeland on grazing communities in Kenya.

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    Most of 80% of Kenya´s land is categorized as arid and semi-arid. Agropastoralism and pastoralism based on livestock production serve as the bedrock of site livelihoods and culture. Pastoralists? livelihoods are affected by frequent and severe droughts, growing demographic pressure and conflicts over natural resource utilization. Vulnerability worsened by accessible grazing lands is often mismanaged and either overgrazed or underutilized leading to land degradation. This work aimed to develop a score index to classify degraded land degree to help technician and pastoralist in adequate use of tools to recovery degraded lands. This trial was conducted using participatory research with four grazing communities (Bisan Biliquo, Bulesa, Korbesa and Malkagalla) in Kenyan dry land from May 2011 to November 2012. There were characterized three sites in each community. First of all, a general characterization was made. In this first characterization were collected information about soil, plant, land use, water source distance and wildlife. Based on this information was chosen spots to make monitoring rangeland on each site. Transect method was used to collect information about bare ground (%), plant cover(%), plant height(cm), number of species(unit), biomass(kg) and litter (kg) production. A practical sheet from Mpala Institute was used to collect data on field. These five parameters were chosen because it was easier to collect by technician and pastoralist. Each parameter was classified in categories according type of measure (%, kg or cm) and could be analyzed and received a grade between 0 and 5. From summing the grades a score index was created to classify stage of degraded land. Five categories were made: 1-6 grades meant high degraded land; 7-12 degraded rangeland; 13-18 recovery rangeland; 19-24 good rangeland and 25-30 healthy rangeland. None of the sites got good or healthy rangeland. In fact all these areas are included in a program to recovering degraded land. The best situation was found in Bulesa where most of areas were classified as recovery land. In this case was recommended to reduce grazing pressure in order to improve litter production. Korbesa place second and was classified as recovery land. It was recommended basically management adjustment for improve biomass production. Bisan Biliquo areas were classified as high or degraded and needed some interventions on management level. In one spot and reseeding was recommended in the two others. Malkagalla was the worse scored site and presented the worse condition rangeland. All spots monitored were classified as high degraded land. Management intervention in this place should be directed to recover biodiversity by reseeding native species and improve biomass production Based on this was highly recommended exclude animal grazing during a period of time. Tools to monitoring rangeland and support diagnostic for degraded lands can be useful to identify problems and propose solutions to recovery degraded lands in dry rangelands

    Galactic or extragalactic chemical tagging for NGC 3201?: Discovery of an anomalous CN-CH relation

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    The origin of the globular cluster (GC) NGC 3201 is under debate. Its retrograde orbit points to an extragalactic origin, but no further chemical evidence supports this idea. Light-element chemical abundances are useful to tag GCs and can be used to shed light on this discussion. Aims. Recently it was shown that the CN and CH indices are useful to identify GCs that are anomalous to those typically found in the Milky Way. A possible origin of anomalous clusters is the merger of two GCs and/or the nucleus of a dwarf galaxy. We aim to derive CN and CH band strengths for red giant stars in NGC3201 and compare these with photometric indices and high-resolution spectroscopy and discuss in the context of GC chemical tagging. Methods. We measure molecular band indices of S(3839) and G4300 for CN and CH, respectively from low-resolution spectra of red giant stars. Gravity and temperature effects are removed. Photometric indices are used to indicate further chemical information on C+N+O or s-process element abundances that are not derived from low-resolution spectra. Results. We found three groups in the CN-CH distribution. A main sequence (S1), a secondary less-populated sequence (S2), and a group of peculiar (pec) CN-weak and CH-weak stars, one of which was previously known. The three groups seem to have different C+N+O and/or s-process element abundances, to be confirmed by high-resolution spectroscopy. These are typical characteristics of anomalous GCs. The CN distribution of NGC 3201 is quadrimodal, which is more common in anomalous clusters. However, NGC 3201 does not belong to the trend of anomalous GCs in the mass-size relation. Conclusions. The globular cluster NGC 3201 shows signs that it can be chemically tagged as anomalous: it has an unusual CN-CH relation, indications that pec-S1-S2 is an increasing sequence of C+N+O or s-process element abundances, and a multi-modal CN distribution that seems to correlate with s-process element abundances. The non-anomalous characteristics are that it has a debatable Fe-spread and it does not follow the trend of mass size of all anomalous clusters. Three scenarios are postulated here: (i) if the sequence pec-S1-S2 has increasing C+N+O and s-process element abundances, NGC 3201 would be the first anomalous GC outside of the mass-size relation; (ii) if the abundances are almost constant, NGC 3201 would be the first non-anomalous GC with multiple CN-CH anti-correlation groups; or (iii) it would be the first anomalous GC without variations in C+N+O and s-process element abundances. In all cases, the definition of anomalous clusters and the scenario in which they have an extragalactic origin must be revised.Fil: Dias, B.. European Southern Observatory Chile.; ChileFil: Araya, I.. Universidad de Valparaiso; ChileFil: Nogueira-Cavalcante, J. P.. Observatorio Do Valongo; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Saker, Leila Yamila. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Shokry, A.. European Southern Observatory Chile.; Chil

    Effects of industrial cashew nut processing on anacardic acid content and allergen recognition by IgE.

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    Made available in DSpace on 2018-05-23T00:36:51Z (GMT). No. of bitstreams: 1 ART18001.pdf: 790323 bytes, checksum: d43e57c68aa556b96975dca6e759ab56 (MD5) Previous issue date: 2018-03-21bitstream/item/177370/1/ART18001.pd

    Estabilidade e adaptabilidade da produtividade de feijão caupi no Estado do Tocantins.

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    O trabalho teve por objetivo avaliar a adaptabilidade e a estabilidade produtiva de genótipos de feijão-caupi no Estado do Tocantins. Os dados desse trabalho foram obtidos de quatro experimentos, conduzidos nas regiões norte e centro-sul do Estado do Tocantins. Foram observadas diferenças significativas na interação genótipo vs locais para a característica produtividade média de grãos (ton. ha-1), evidenciando a existência de variabilidade entre genótipos. A produtividade variou de 1.120,8 a 2.727,5 ton. ha-1, destacando-se como a mais produtiva a cultivar BRS-TUCUMAQUE.CONAC 2012. Disponível em: http://www.conac2012.org/resumos/pdf/233a.pdf. Acesso em: 07 ago. 2013

    Fertirrigação nitrogenada para produção de macieiras Eva e Princesa em Petrolina-PE.

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    O presente trabalho foi desenvolvido com o objetivo de avaliar produção de frutos das 26 macieiras ?Eva? e ?Princesa?, em função a fertirrigação nitrogenada em Petrolina-PE

    Qualidade de frutos de macieiras Eva e Princesa sob fertirrigação nitrogenada em Petrolina-PE.

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    O presente trabalho foi desenvolvido com o objetivo de avaliar a qualidade física e química de frutos das macieiras Eva e Princesa, em função a fertirrigação nitrogenada em Petrolina-PE
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