1,812 research outputs found

    A combination of SEM and EDX studies on a clay-based natural composite with animal fibre and its mechanical implications

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    A variety of natural fibres are nowadays being utilized as soil reinforcement. Test results demonstrate the positive effects of adding natural fibres to soils, in that they decrease shrinkage, reduce curing time and enhance compressive, flexural and shear strength if an optimum reinforcement ratio can be utilised. This paper describes a study which uses a Scanning Electron Microscope (SEM) and an Energy Diffraction Analysis of X-rays (EDX) technique on clay-based composites stabilized with natural polymer and fibres. Different dosages of fibres and several types of soils have been used in this study with the aim of determining advantageous properties for building material applications. SEM and EDX test results reveal the degree of bonding between the particles of soil and the natural fibers. This has enabled a better understanding of the micro-morphology of the natural fibers and their effect on the overall composite material structure. Microscopic analysis was combined with mechanical tests to establish the different strength characteristics of every soil

    An ACO-based Hyper-heuristic for Sequencing Many-objective Evolutionary Algorithms that Consider Different Ways to Incorporate the DM's Preferences

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    Many-objective optimization is an area of interest common to researchers, professionals, and practitioners because of its real-world implications. Preference incorporation into Multi-Objective Evolutionary Algorithms (MOEAs) is one of the current approaches to treat Many-Objective Optimization Problems (MaOPs). Some recent studies have focused on the advantages of embedding preference models based on interval outranking into MOEAs; several models have been proposed to achieve it. Since there are many factors influencing the choice of the best outranking model, there is no clear notion of which is the best model to incorporate the preferences of the decision maker into a particular problem. This paper proposes a hyper-heuristic algorithm—named HyperACO—that searches for the best combination of several interval outranking models embedded into MOEAs to solve MaOPs. HyperACO is able not only to select the most appropriate model but also to combine the already existing models to solve a specific MaOP correctly. The results obtained on the DTLZ and WFG test suites corroborate that HyperACO can hybridize MOEAs with a combined preference model that is suitable to the problem being solved. Performance comparisons with other state-of-the-art MOEAs and tests for statistical significance validate this conclusion

    Synthesis of quinoxaline 1,4-di-N-oxide derivatives on solid support using room temperature and microwave-assisted solvent-free procedures

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    We describe the synthesis of 12 new ethyl and methyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives on solid supports with room temperature and microwave-assisted solvent-free procedures. Results show that solid supports have good catalytic activity in the formation of quinoxaline 1,4-di-N-oxide derivatives. We found that florisil and montmorillonite KSF and K10 could be used as new, easily available, inexpensive alternatives of catalysts. Additionally, room temperature and microwave-irradiation solvent-free synthesis was more efficient than a conventional procedure (Beirut reaction), reducing reaction time and increasing yield

    Manipulation of Ploidy in Caenorhabditis elegans

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    Mechanisms that involve whole genome polyploidy play important roles in development and evolution; also, an abnormal generation of tetraploid cells has been associated with both the progression of cancer and the development of drug resistance. Until now, it has not been feasible to easily manipulate the ploidy of a multicellular animal without generating mostly sterile progeny. Presented here is a simple and rapid protocol for generating tetraploid Caenorhabditis elegans animals from any diploid strain. This method allows the user to create a bias in chromosome segregation during meiosis, ultimately increasing ploidy in C. elegans. This strategy relies on the transient reduction of expression of the rec-8 gene to generate diploid gametes. A rec-8 mutant produces diploid gametes that can potentially produce tetraploids upon fertilization. This tractable scheme has been used to generate tetraploid strains carrying mutations and chromosome rearrangements to gain insight into chromosomal dynamics and interactions during pairing and synapsis in meiosis. This method is efficient for generating stable tetraploid strains without genetic markers, can be applied to any diploid strain, and can be used to derive triploid C. elegans. This straightforward method is useful for investigating other fundamental biological questions relevant to genome instability, gene dosage, biological scaling, extracellular signaling, adaptation to stress, development of resistance to drugs, and mechanisms of speciation

    The Large Aperture GRB Observatory

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    The Large Aperture GRB Observatory (LAGO) is aiming at the detection of the high energy (around 100 GeV) component of Gamma Ray Bursts, using the single particle technique in arrays of Water Cherenkov Detectors (WCD) in high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). WCD at high altitude offer a unique possibility of detecting low gamma fluxes in the 10 GeV - 1 TeV range. The status of the Observatory and data collected from 2007 to date will be presented.Comment: 4 pages, proceeding of 31st ICRC 200

    Water Cherenkov Detectors response to a Gamma Ray Burst in the Large Aperture GRB Observatory

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    In order to characterise the behaviour of Water Cherenkov Detectors (WCD) under a sudden increase of 1 GeV - 1 TeV background photons from a Gamma Ray Burst (GRB), simulations were conducted and compared to data acquired by the WCD of the Large Aperture GRB Observatory (LAGO). The LAGO operates arrays of WCD at high altitude to detect GRBs using the single particle technique. The LAGO sensitivity to GRBs is derived from the reported simulations of the gamma initiated particle showers in the atmosphere and the WCD response to secondaries.Comment: 5 pages, proceeding of the 31st ICRC 200

    Tumor de células de la granulosa: diagnóstico, tratamiento hormonal e intervención quirúrgica en yegua criolla colombiana.

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      Severe reproductive problems in mares are related to ovarian tumors. Among these, the Granulosa Cell Tumor (GCT) is the most commonly diagnosed, although it represents only 2.5% of all the tumors in horses. The following investigation is a case study of GCT in one creole adult mare, which presented a similar behavior as the male, virilism and anestrus. An ultrasonographic examination was used to identify the tumor and GnRH was administered as hormonal treatment; in the following weeks an ovariectomy was done as a surgical treatment. The histopathologic examination of the neoplasic tissue evidenced cellular proliferation with similar morphologic characteristics as the granulosa cells, which is the definitive diagnosis for GCT. The hormonal and surgical treatment was satisfactory, verified by the cessation of abnormal behaviors and by the return of the cyclicity of the remaining ovary. It is expected that in the following months the mare can be used again to reproduction. Graves problemas reproductivos se han asociado a tumores ováricos en yeguas. Dentro de estos el Tumor de Células de la Granulosa (TCG) sigue siendo el más diagnosticado, aunque sólo representa el 2.5% de todos los tumores del equino. El siguiente es un estudio de caso de TCG en una yegua criolla adulta que manifestó comportamiento similar al macho, virilismo y anestro. Se utilizó el examen ultrasonográfico para identificar el tumor y se administró GnRH como tratamiento hormonal; en semanas posteriores se procedió a la ovariectomia como tratamiento quirúrgico. El examen histopatológico del tejido neoplásico evidenció proliferación celular con características morfológicamente semejantes a las células de la granulosa, siendo el diagnóstico definitivo TCG. Se concluye que el tratamiento hormonal y quirúrgico fue satisfactorio, lo cual se pudo comprobar por el cese de comportamientos anormales y el retorno de la ciclicidad del ovario restante, se espera que en meses posteriores la yegua pueda ser utilizada nuevamente para reproducción

    Seminoma metastático: descripción histomorfológica

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     The primary testicular tumors in the canine species are originated, generally, by three types (germ cells, interstitial cells and sustentacular cells). These may occur of singular or mixed form, frequently, in adult animals with cryptorchidism. In the present article was realized the histomorphologic description in a primary testicular tumor with regional lymph node metastasis, observed in an adult dog, mixed breed, 15 year old. For this purpose, was realized a bilateral orchiectomy, collecting samples of testicle and iliac lymph node with suspect of neoplasia. It was performed the routine process of a testicular and lymph node fragment for histological section and haematoxylin-eosin technique. In the microscopic exam was identified a proliferation of neoplastic cells, constituted by cells of the seminiferous tubules. This cellular population also was observed in the lymph node. The diagnosis was Seminoma with metastasis in the regional lymph node. We concluded that histomorphologic description is a fundamental tool for diagnostic and classification of the testicular tumors. Los tumores testiculares primarios de la especie canina son originados, principalmente, por tres tipos células (germinativas, intersticiales y sustentaculares). Estos pueden presentarse de forma singular o de forma mixta, frecuentemente, en animales adultos que padecen criptorquidismo. En el presente artículo se realiza la descripción histomorfológica en un tumor testicular primario con metástasis en ganglio linfático regional, observado en un perro adulto, sin raza definida, con 15 años de edad. Para este propósito, fue realizada una orquiectomía bilateral del animal, recolectándose también el ganglio linfático ilíaco, por sospecha de neoplasia. Se efectuó el procesamiento de rutina en un fragmento de testículo y otro de ganglio linfático para corte histológico y coloración con la técnica de Hematoxilina y Eosina. En el examen microscópico se identificó una proliferación de células neoplásicas procedentes de los túbulos seminíferos. La misma población de células fue observada en el ganglio linfático. El diagnóstico fue Seminoma con metástasis en ganglio linfático regional. Se concluye que la descripción histomorfológica es una herramienta fundamental para el diagnóstico y la clasificación de los tumores testiculares

    American Association of Colleges of Pharmacy (AACP) Co-Curriculum Toolkit

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    The co-curriculum is intended to run parallel to the formal curriculum and support the development of students’ professional knowledge, skills, abilities, behaviors, and attitudes, including scientific foundation, knowledge application, and practice competencies. Additionally, the co-curriculum can also support proficiency in skills and achievement of competencies that are concurrently taught within the formal curriculum. ACPE evaluates the way programs assess students’ acquisition of knowledge and application of knowledge to practice within co-curricular experiences and especially how they advance the professional development of students within affective domain areas of learning
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