2,763 research outputs found

    Organic Molecules in the Galactic Center. Hot Core Chemistry without Hot Cores

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    We study the origin of large abundances of complex organic molecules in the Galactic center (GC). We carried out a systematic study of the complex organic molecules CH3OH, C2H5OH, (CH3)2O, HCOOCH3, HCOOH, CH3COOH, H2CO, and CS toward 40 GC molecular clouds. Using the LTE approximation, we derived the physical properties of GC molecular clouds and the abundances of the complex molecules.The CH3OH abundance between clouds varies by nearly two orders of magnitude from 2.4x10^{-8} to 1.1x10^{-6}. The abundance of the other complex organic molecules relative to that of CH3OH is basically independent of the CH3OH abundance, with variations of only a factor 4-8. The abundances of complex organic molecules in the GC are compared with those measured in hot cores and hot corinos, in which these complex molecules are also abundant. We find that both the abundance and the abundance ratios of the complex molecules relative to CH3OH in hot cores are similar to those found in the GC clouds. However, hot corinos show different abundance ratios than observed in hot cores and in GC clouds. The rather constant abundance of all the complex molecules relative to CH3OH suggests that all complex molecules are ejected from grain mantles by shocks. Frequent (similar 10^{5}years) shocks with velocities >6km/s are required to explain the high abundances in gas phase of complex organic molecules in the GC molecular clouds. The rather uniform abundance ratios in the GC clouds and in Galactic hot cores indicate a similar average composition of grain mantles in both kinds of regions. The Sickle and the Thermal Radio Arches, affected by UV radiation, show different relative abundances in the complex organic molecules due to the differentially photodissociation of these molecules.Comment: 18 pages, 10 Postscript figures, uses aa.cls, aa.bst, 10pt.rtx, natbib.sty, revsymb.sty revtex4.cls, aps.rtx and aalongtabl.sty. Accepted in A&A 2006. version 2. relocated figures and tables. Language editor suggestions. added reference

    Conjunctival Melanoma: A New Clinical and Therapeutical Approach

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    Melanoma involving the conjunctiva is extremely rare. Graver prognosis has been reported with primary conjunctival melanoma than with their cutaneous counterparts [Collin et al.: Aust N Z J Ophthalmol 1986;14:29–34]. Among conjunctival melanomas, two significant risk factors for tumour-related death have been identified: (i) age older than 55 years and (ii) unfavourable tumour location (caruncle, cornea, fornix, palpebral conjunctiva) [Werschnik and Lommatzsch: Am J Clin Oncol 2002;25:248–255]. Here we present a rare case of lentigo maligna involving the palpebral, bulbar conjunctiva and the caruncle. We describe dermoscopic patterns observed and the use of a novel ocular melanoma therapy with topical imiquimod

    Crack-Depth Prediction in Steel Based on Cooling Rate

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    One criterion for the evaluation of surface cracks in steel welds is to analyze the depth of the crack, because it is an effective indicator of its potential risk. This paper proposes a new methodology to obtain an accurate crack-depth prediction model based on the combination of infrared thermography and the 3D reconstruction procedure. In order to do this, a study of the cooling rate of the steel is implemented through active infrared thermography, allowing the study of the differential thermal behavior of the steel in the fissured zone with respect to the nonfissured zone. These cooling rate data are correlated with the real geometry of the crack, which is obtained with the 3D reconstruction of the welds through a macrophotogrammetric procedure. In this way, it is possible to analyze the correlation between cooling rate and depth through the different zones of the crack. The results of the study allow the establishment of an accurate predictive depth model which enables the study of the depth of the crack using only the cooling rate data. In this way, the remote measure of the depth of the surface steel crack based on thermography is possible

    3D morphological features and antibiotic resistance in L. monocytogenes - Pseudomonas sp. biofilms

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    1 poster presented at Biofilms 7, Porto, 26-28 June 2016This research was financially supported by the Spanish Research Council (Project ref.201670 E008)N

    Whole genome-based taxonomy of Shewanella and Parashewanella

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    The family Shewanellaceae currently comprises three genera, Shewanella, Parashewanella and Psychrobium, the latter represented by a single species. From the second half of the 1990s, the number of novel species in the Shewanellaceae has steadily increased, suggesting that the true diversity of this family has only begun to emerge. In recent years, efforts to provide a genus-wide, whole genome-based taxonomy for Shewanella have been limited by the lack of numerous type strain genome sequences. To shed light on this question, we sequenced all Shewanella type strains that lacked a publicly available wholegenome sequence. Using state-of-the-art phylogenomic methods, here we provide a genus-wide taxonomy of Shewanella and Parashewanella that resulted in the identification of 48 novel species represented by 73 sequenced isolates, and we propose the correction of 43 misidentified non-type-strain isolates. Our work sets a reference for family-wide comparative genomic studies addressing genetic or ecophysiological aspects of Shewanellaceae, as well as subsequent species descriptions

    Digital models of stone samples for didactical purposes

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    This paper presents a v irtual methodology based on the generation of virtual models of stones in the context of the virtual laboratories for the acquisition and evaluation of competences in stones identification. The generation of the models is carried out using a procedure based on close-range photogrammetry that allows to obtain a scaled mesh models with radiometric information and low file weight. The proposed methodology has been designed ad-hoc following the economy, quality and reality criteria to ensure a good adequacy, guaranteeing an adequate adaptation to the teaching-learning process and the integration of the models into working packages, which can be easily integrated in earning management system (LMS) platforms. The generated 3D models have a high level of detail and enable the interaction to take measurements, make cross sections and use specific tools that allow the student to perform a thorough analysis and identification of the stone using free/open source software.- (undefined

    Learning methodology based on weld virtual models in the mechanical engineering classroom

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    13 pp.Welding inspection activities within engineering degree programs are usable in practice. The competences acquired through these are usually contextualized in laboratory environments, using for its physical samples of welds, which used to be are scarce and expensive. In this study, a new methodology based on threedimensional macro‐photogrammetric models of welds is designed and actively implemented in the classroom, with students of mechanical engineering to evaluate different aspects about the suitability and learning performance of this novel methodology. To obtain the research conclusions, the activities have been chosen to evaluate four important aspects of it: usability, learning, motivation, and scalability. Results demonstrate that the adequate acceptation of the novel methodology studied, making possible new approaches for the acquisition of the competences related the welding inspection in the engineering education contextS

    Bases fisiopatológicas del tratamiento de la enfermedad de Scheüermann

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    Los estudios realizados sobre la etiopatogenia de la enfermedad de Scheüermann, no han mostrado hasta el momento suficientes datos para determinar con exactitud cual es la verdadera causa del acuñamiento vertebral, pero es evidente que la deformidad vertebral es consecuencia de una debilidad osteocondral en una etapa de crecimiento sobre la que actúan factores mecánicos. Sobre esta base se plantean los fundamentos del tratamiento conservador analizando los resultados obtenidos con el corsé de Milwaukee y con el corsé de New York de bajo perfil. Los resultados demuestran una clara ventaja del corsé de Milwaukee para las curvas altas, mientras que las curvas con ápex por debajo de T7 se corrigen bien en su valor angular con el corsé de bajo perfil, pero con menor corrección del ángulo de acuñamiento.As to the ethiopathogeny of Scheüermann's disease there is no consensus about the true cause of vertebral body wedging. It seems clear that the deformity of vertebral bodies is a consecuence of osteochondral weakness in a growth period in which mechanic factors are involved. This provides fundamentals of conservative treatment analvzing the results obtained with the Milwaukee and New York braces. The results demostrate a clear adventage of Milwaukee brace for upper kiphosis. On the other hand, low profile braces work well on curves with apex below T7, although less wedge angle correction is obtained
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