92 research outputs found

    Accuracy evaluation of the semi-automatic 3D modeling for historical building information models

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    It is stated that 3D recording and modelling of heritage buildings entails accurate building models (as-built). However, this paper presents an analysis of the 3D modelling accuracy for the creation of historical building information models (HBIM), considering the complexity and the deformations of historical buildings, using point cloud data and BIM tools. The 3D modelling processes analysed are based on a three-stage semi-automatic approach leading to the generation of HBIM, including manual and automatic processes. The three stages consist of: (a) optical and terrestrial laser scanning; (b) meshing processes; and finally (c) 3D solid modelling to be assembled into HBIM. Next, this approach analysed the mesh deformations generated automatically in comparison to the initial point cloud data. The deformations and the accuracy evaluation have been undertaken using different commercial software. Finally, our modelling approach shows that it can improve the accuracy of the 3D models achieved using existing BIM technologies

    Metodología BIM en el grado de edificación: modelo de taller en la asignatura Expresión Gráfica de Tecnologías

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    The concept of BIM implies a radical change in the way of facing the architectural design and the life cycle process of the projects and the buildings. It is an efficient and open system of communication and cooperation between the different operators involved in the construction process and, therefore, it becomes in a suitable tool for its implementation in the Technical Schools of Engineering and Architecture. This paper defends the recognition of the BIM methodology as a collaborative and coordinated instrument for its application in the university teaching in degrees of this field of knowledge, so that the flow of interdisciplinary information is efficient. The experience of the implementation of this methodology in the Degree in Building is described. It is based on a workshop-integrator model in the subject called Graphic Expression of Technologies. Subsequently, educational enquiries derived from the innovation developed are collected, showing its benefits for the student body as regards learning, and also the limitations found. In conclusion, the outcomes obtained lead to continue supporting this technological integration. Finally, a series of recommendations for its improvement are provided, concerning the way to guide the students throughout the experience, and also related to the teaching organisation through the curriculum

    Implantación de metodología BIM en el Grado de Edificación. Modelo de taller-integrador en la asignatura de Expresión Gráfica de Tecnologías

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    Resumen: El concepto de BIM implica un cambio radical en la manera de afrontar el diseño arquitectónico y el proceso de ciclo de vida del proyecto y del edificio. Se trata de un sistema eficiente y abierto de comunicación y cooperación entre los distintos operadores del proceso constructivo y, por tanto, idóneo para su implantación en las Escuelas Técnicas de Ingeniería y Arquitectura. Esta comunicación defiende el reconocimiento de la metodología BIM como instrumento de trabajo colaborativo y coordinado para su aplicación en la docencia, a fin de que el flujo de información interdisciplinar sea eficiente. Se describe la experiencia de la implantación de esta metodología en el Grado de Edificación, a través de un modelo de taller-integrador en la asignatura de Expresión Gráfica de Tecnologías. Posteriormente, se recogen experiencias docentes derivadas de la innovación desarrollada, que llevan a seguir apostando por esta integración tecnológica, para cuya mejora se aportan finalmente una serie de recomendaciones. Abstract: The concept of BIM implies a radical change in the way of facing the architectural design and the life cycle process of the project and the building. It is an efficient and open system of communication and cooperation between the different operators within the construction process and, therefore, suitable for its implementation in the Technical Schools of Engineering and Architecture. This paper defends the recognition of the BIM methodology as a collaborative and coordinated tool for its application in teaching, so that the flow of interdisciplinary information is efficient. The experience of the implementation of this methodology in the Degree in Building is described, through a workshop-integrator model in the subject called Graphic Expression of Technologies. Subsequently, educational enquiries derived from the innovation developed are collected, which lead to continue supporting this technological integration. Finally, a series of recommendations for its improvement are provided

    Two highly divergent alcohol dehydrogenases of melon exhibit fruit ripening-specific expression and distinct biochemical characteristics

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    Alcohol dehydrogenases (ADH) participate in the biosynthetic pathway of aroma volatiles in fruit by interconverting aldehydes to alcohols and providing substrates for the formation of esters. Two highly divergent ADH genes (15% identity at the amino acid level) of Cantaloupe Charentais melon (Cucumis melo var. Cantalupensis) have been isolated. Cm-ADH1 belongs to the medium-chain zinc-binding type of ADHs and is highly similar to all ADH genes expressed in fruit isolated so far. Cm-ADH2 belongs to the short-chain type of ADHs. The two encoded proteins are enzymatically active upon expression in yeast. Cm-ADH1 has strong preference for NAPDH as a co-factor, whereas Cm-ADH2 preferentially uses NADH. Both Cm-ADH proteins are much more active as reductases with Kms 10–20 times lower for the conversion of aldehydes to alcohols than for the dehydrogenation of alcohols to aldehydes. They both show strong preference for aliphatic aldehydes but Cm-ADH1 is capable of reducing branched aldehydes such as 3-methylbutyraldehyde, whereas Cm-ADH2 cannot. Both Cm-ADH genes are expressed specifically in fruit and up-regulated during ripening. Gene expression as well as total ADH activity are strongly inhibited in antisense ACC oxidase melons and in melon fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), indicating a positive regulation by ethylene. These data suggest that each of the Cm-ADH protein plays a specific role in the regulation of aroma biosynthesis in melon fruit

    On Multi-Index Filtrations Associated to Weierstraß Semigroups

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    This paper is a survey on the main techniques involved in the computation of the Weierstraß semigroup at several points of curves defined over perfect fields, with special emphasis on the case of two points. Some hints about the usage of some packages of the computer algebra software Singular are also given; these are however only valid for curves defined over Fp with p a prime number

    Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release

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    Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed

    An ultrahot Neptune in the Neptune desert

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    About one out of 200 Sun-like stars has a planet with an orbital period shorter than one day: an ultra-short-period planet (Sanchis-ojeda et al. 2014; Winn et al. 2018). All of the previously known ultra-short-period planets are either hot Jupiters, with sizes above 10 Earth radii (Re), or apparently rocky planets smaller than 2 Re. Such lack of planets of intermediate size (the "hot Neptune desert") has been interpreted as the inability of low-mass planets to retain any hydrogen/helium (H/He) envelope in the face of strong stellar irradiation. Here, we report the discovery of an ultra-short-period planet with a radius of 4.6 Re and a mass of 29 Me, firmly in the hot Neptune desert. Data from the Transiting Exoplanet Survey Satellite (Ricker et al. 2015) revealed transits of the bright Sun-like star \starname\, every 0.79 days. The planet's mean density is similar to that of Neptune, and according to thermal evolution models, it has a H/He-rich envelope constituting 9.0^(+2.7)_(-2.9)% of the total mass. With an equilibrium temperature around 2000 K, it is unclear how this "ultra-hot Neptune" managed to retain such an envelope. Follow-up observations of the planet's atmosphere to better understand its origin and physical nature will be facilitated by the star's brightness (Vmag=9.8)

    An insertional mutagenesis programme with an enhancer trap for the identification and tagging of genes involved in abiotic stress tolerance in the tomato wild-related species Solanum pennellii

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    Salinity and drought have a huge impact on agriculture since there are few areas free of these abiotic stresses and the problem continues to increase. In tomato, the most important horticultural crop worldwide, there are accessions of wild-related species with a high degree of tolerance to salinity and drought. Thus, the finding of insertional mutants with other tolerance levels could lead to the identification and tagging of key genes responsible for abiotic stress tolerance. To this end, we are performing an insertional mutagenesis programme with an enhancer trap in the tomato wild-related species Solanum pennellii. First, we developed an efficient transformation method which has allowed us to generate more than 2,000 T-DNA lines. Next, the collection of S. pennelli T0 lines has been screened in saline or drought conditions and several presumptive mutants have been selected for their salt and drought sensitivity. Moreover, T-DNA lines with expression of the reporter uidA gene in specific organs, such as vascular bundles, trichomes and stomata, which may play key roles in processes related to abiotic stress tolerance, have been identified. Finally, the growth of T-DNA lines in control conditions allowed us the identification of different development mutants. Taking into account that progenies from the lines are being obtained and that the collection of T-DNA lines is going to enlarge progressively due to the high transformation efficiency achieved, there are great possibilities for identifying key genes involved in different tolerance mechanisms to salinity and drought

    Is there a common water-activity limit for the three domains of life?

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    Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (a w) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650-0.605 a w. Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 a w). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 a w for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 a w for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life
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