619 research outputs found
A probabilistic model for crystal growth applied to protein deposition at the microscale
A probabilistic discrete model for 2D protein crystal growth is presented.
This model takes into account the available space and can describe growing
processes of different nature due to the versatility of its parameters which
gives the model great flexibility. The accuracy of the simulation is tested
against a real protein (SbpA) crystallization experiment showing high agreement
between the proposed model and the actual images of the nucleation process.
Finally, it is also discussed how the regularity of the interface (i.e. the
curve that separates the crystal from the substrate) affects to the evolution
of the simulation.Comment: 13 pages, 12 figure
Management of uncertain pairwise comparisons in AHP through probabilistic concepts
[EN] Fast and judicious decision-making is paramount for the success of many activities and processes. However, various degrees of difficulty may affect the achievement of effective and optimal solutions. Decisions should ideally meet the best trade-off among as many of the involved factors as possible, especially in the case of complex problems. Substantial cognitive and technical skills are indispensable, while not always sufficient, to carry out optimal evaluations. One of the most common causes of wrong decisions derives from uncertainty and vagueness in making forecasts or attributing judgments. The literature shows numerous efforts towards the optimization and modeling of uncertain contexts by means of probabilistic approaches. This paper proposes the use of probability theory to estimate uncertain expert judgments within the framework of the analytic hierarchy process and, more specifically, within a linearization scheme developed by the authors. After describing the necessary probabilistic concepts of interest, the main results are developed. These results can be summarized as using various kinds of random variables with uncertainty embodied in undecided pairwise comparisons. A case study focused on the maintenance management of an industrial water distribution system exemplifies the approach.Benítez López, J.; Carpitella, S.; Certa, A.; Izquierdo Sebastián, J. (2019). Management of uncertain pairwise comparisons in AHP through probabilistic concepts. Applied Soft Computing. 78:274-285. https://doi.org/10.1016/j.asoc.2019.02.020S2742857
Strategies towards sustainability environmental from the local areas and the university
El propósito del presente trabajo es explorar un posible arreglo socioambiental pensado desde lo local que propicie el desarrollo sustentable, por medio del privilegio de la articulación de lo social (ciudadanía y educación) con el medio ambiente (capacidad de renovación).
El planteamiento central es que ante un modelo social dominante que es insustentable, en el sentido que refuerza la desigualdad socioeconómica y el deterioro ambiental; se demanda pensar y actuar en formas novedosas e integradoras de lo social con la natural y del presente con el futuro para hacer posible sentar bases para un desarrollo sustentable de largo plazo. Para tal fin, se formula un arreglo que articule lo social (ciudadanía y educación) con el medio ambiente (capacidad de renovación) desde ámbitos locales, por medio de estrategias de acción gestionadas socialmente.The aim of this paper is to explore and present a suitable socio-environmental proposal conducive to sustainable development considering the local aspects emphasizing on the joint between the social (citizenship and education) with the environmental (renewability). The rationale of the study is that having a dominant unsustainable social model that reinforces socioeconomic inequality and environmental degradation, a need of developing more integrative and innovative ways to cope with the social and the natural as well as the present and the future is required in order to lay the foundations for a more long-term sustainable development.
To that end, a suitable arrangement is presented in order to articulate the social aspects (citizenship and education) to the environmental ones (renewability) from a local perspective, managed through social action strategies.Fil: González López, Sergio.
Universidad Autónoma del Estado de México. Instituto de Estudios sobre la
Universidad.Fil: Salvador Benítez, J. Loreto.
Universidad Autónoma del Estado de México. Instituto de Estudios sobre la
Universidad.Fil: Arand a Sánchez, José María.
Universidad Autónoma del Estado de México. Instituto de Estudios sobre la
Universidad
Global patterns and predictors of avian population density
Agencia de Innovación y Desarrollo
de Andalucía, Grant/Award Number:
EMERGIA20_00252; H2020 Marie
Skłodowska- Curie Actions, Grant/
Award Number: 891052; Ministero
dell'Istruzione, dell'Università e della
Ricerca, Grant/Award Number: Rita Levi
Montalcini programAim: How population density varies across animal species in the context of environ-
mental gradients, and associated migratory strategies, remains poorly understood.
The recent influx of avian trait data and population density estimates allows these
patterns to be described and explored in unprecedented detail. This study aims to
identify the main macroecological drivers of population density in birds.
Location: Global.
Time period: 1970–2021.
Major taxa studied: Birds (Aves).
Methods: We collated a dataset of 5072 local population density estimates for 1853
species and modelled population density as a function of trait and environmental
predictors in a Bayesian framework accounting for phylogenetic and spatial autocor-
relation. We explored the influence of body mass, diet, primary lifestyle, mating sys-
tem, nesting behaviour, territoriality, and migratory behaviour on population density,
accounting for a range of environmental variables, including preferred habitat type,
primary productivity, precipitation and temperature. Based on this empirical baseline,
we then predicted the mean population density for 9089 species of birds and esti-
mated global geographic patterns of bird population density.
Results: Population density was lower in species with larger body mass and higher
trophic levels, and also declined in territorial species, migratory species, brood para-
sites and species inhabiting resource-poor habitat types (e.g., deserts). Conversely,
population density increased in cooperative breeders. Environmental drivers were
most influential for migratory birds, with precipitation and temperature both associ-
ated with higher population density. Overall, bird population densities were higher at
lower latitudes.
Main conclusions: Our results support previous findings on the role of body mass,
diet and environmental gradients, but also reveal novel species-specific drivers of
avian densities related to reproduction, migration and resource- holding behaviour.
Substantial fine-scale variation remains unexplained. We provide a global dataset of
population density predictions for use in macroecological analyses and conservation
assessments.Agencia de Innovacion y Desarrollo de Andalucia
EMERGIA20_00252H2020 Marie Sklodowska-Curie Actions
891052Ministry of Education, Universities and Research (MIUR
Consistent Clustering of Elements in Large Pairwise Comparison Matrices
[EN] In multi-attribute decision making the number of decision elements under consideration may be huge, especially for complex, real-world problems. Typically these elements are clustered and then the clusters organized hierarchically to reduce the number of elements to be simultaneously handled. These decomposition methodologies are intended to bring the problem within the cognitive ability of decision makers. However, such methodologies have disadvantages, and it may happen that such a priori clustering is not clear, and/or the problem has previously been addressed without any grouping action. This is the situation for the case study we address, in which a panel of experts gives opinions about the operation of 15 previously established district metered areas in a real water distribution system. Large pairwise comparison matrices may also be found when building comparisons of elements using large bodies of information. In this paper, we address a consistent compression of an AHP comparison matrix that collapses the judgments corresponding to a given number of compared elements. As a result, an a posteriori clustering of various elements becomes possible. In our case study, such a clustering offers several added benefits, including the identification of hidden or unknown criteria to cluster the considered elements of the problem. (C) 2018 Elsevier B.V. All rights reserved.Benítez López, J.; Carpitella, S.; Certa, A.; Ilaya-Ayza, AE.; Izquierdo Sebastián, J. (2018). Consistent Clustering of Elements in Large Pairwise Comparison Matrices. Journal of Computational and Applied Mathematics. 343:98-112. https://doi.org/10.1016/j.cam.2018.04.041S9811234
A hybrid multicriteria approach to GPR image mining applied to water supply system maintenance
[EN] Data processing techniques for Ground Penetrating Radar (GPR) image mining provide essential information to optimize maintenance management of Water Supply Systems (WSSs). These techniques aim to elaborate on radargrams in order to produce meaningful graphical representations of critical buried components of WSSs. These representations are helpful non-destructive evaluation tools to prevent possible failures in WSSs by keeping them adequately monitored. This paper proposes an integrated multi-criteria decision making (MCDM) approach to prioritize various data processing techniques by means of ranking their outputs, namely their resulting GPR image representations. The Fuzzy Analytic Hierarchy Process (FAHP) is applied to weight various evaluation criteria, with the purpose of managing vagueness and uncertainty characterizing experts' judgments. Then, the Elimination Et Choix Traduisant la REalite III (ELECTRE III) method is used to obtain the final ranking of alternatives. A real case study, focusing on a set of four GPR images as outputs of different data processing techniques, is presented to prove the usefulness of the proposed hybrid approach. In particular, the GPR images are ranked according the evaluation of five criteria namely visualization, interpretation, identification of features, extraction of information and affordability. The findings offer a structured support in selecting the most suitable data processing technique(s) to explore WSS underground. In the presented case, two options, namely the variance filter and the subtraction methods, offer the best results. (C) 2018 Elsevier B.V. All rights reserved.Part of this work has been developed under the support of the Universitat Politecnica de Valencia, Valencia (Spain), grant: UPV mobility program for PhD students, awarded to the first author, and of Fundacion Carolina PhD, within its short stage scholarship program awarded to the second author.Carpitella, S.; Ocaña-Levario, SJ.; Benítez López, J.; Certa, A.; Izquierdo Sebastián, J. (2018). A hybrid multicriteria approach to GPR image mining applied to water supply system maintenance. Journal of Applied Geophysics. 159:754-764. https://doi.org/10.1016/j.jappgeo.2018.10.021S75476415
Papel de las bacterias del ácido láctico en verduras fermentadas
The consumption of fermented vegetables is widespread throughout the world and represents an important component of the human diet with considerable contribution to the food supply for a world population in continuous growth. Many of the fermented vegetables share a general process which requires salting and acidification steps. Among the microorganisms responsible for fermentation, lactic acid bacteria are the most relevant with important organoleptic, quality and safety benefits. This review deals with the microbial ecology of fermented vegetables focusing on the biodiversity of lactic acid bacteria, the most important molecular techniques used for their identification and genotyping, their importance for the formation of biofilms as well as their use as starter cultures for obtaining high-quality and safe vegetable products.El consumo de vegetales fermentados está muy extendido en el mundo y representa un componente importante de la dieta humana con un apoyo considerable a la cadena alimentaria para una población mundial en continuo crecimiento. Muchos de los vegetales fermentados comparten un proceso general, que requiere una puesta en salmuera y acidificación. Entre los microorganismos responsables de la fermentación, las bacterias del ácido láctico son las más relevantes con una importante influencia sobre aspectos organolépticos, de calidad y seguridad del producto final. Esta revisión trata sobre la ecología microbiana de los vegetales fermentados, prestando especial atención a la biodiversidad de las bacterias del ácido láctico, las técnicas moleculares más importantes utilizadas para su identificación y genotipado, su importancia para la formación de biofilms y su uso como cultivos iniciadores multifuncionales para la obtención de productos vegetales de alta calidad y seguridad
Accurate estimation of the minimum primary channel activity time in cognitive radio based on periodic spectrum sensing observations
The minimum duration of idle/busy periods in a primary channel is an important parameter in Cognitive Radio (CR) systems since it determines the minimum amount of time the primary channel will be available for opportunistic transmission (in the case of idle periods) or the minimum amount of time the CR system will have to wait before a busy primary channel can become available again for opportunistic transmission (in the case of busy periods). Recent research has demonstrated that the value of the minimum period plays a critical role in the estimation of primary channel activity statistics, which can be estimated accurately only if the minimum period duration is accurately known. Given the importance of this parameter, this work analyses the problem of estimating the minimum (idle/busy) period in a primary channel based on periodic spectrum sensing observations and proposes novel methods to enable an accurate estimation. The obtained simulation results demonstrate that the proposed methods can provide an accurate estimation of the minimum period regardless of the employed sensing period (i.e., the main aspect that constrains the available time resolution)
The impact of hunting on tropical mammal and bird populations
Hunting is a major driver of biodiversity loss, but a systematic large-scale estimate of hunting-induced defaunation is lacking. We synthesized 176 studies to quantify hunting-induced declines of mammal and bird populations across the tropics. Bird and mammal abundances declined by 58% (25 to 76%) and by 83% (72 to 90%) in hunted compared with unhunted areas. Bird and mammal populations were depleted within 7 and 40 kilometers from hunters’ access points (roads and settlements). Additionally, hunting pressure was higher in areas with better accessibility to major towns where wild meat could be traded. Mammal population densities were lower outside protected areas, particularly because of commercial hunting. Strategies to sustainably manage wild meat hunting in both protected and unprotected tropical ecosystems are urgently needed to avoid further defaunation
Transcriptomic profiling of skeletal muscle reveals candidate genes influencing muscle growth and associated lipid composition in Portuguese local pig breeds
Gene expression is one of the main factors to influence meat quality by modulating fatty acid metabolism, composition, and deposition rates in muscle tissue. This study aimed to explore the transcriptomics of the Longissimus lumborum muscle in two local pig breeds with distinct genetic background using next-generation sequencing technology and Real-Time qPCR. RNA-seq yielded 49 differentially expressed genes between breeds, 34 overexpressed in the Alentejano (AL) and 15 in the Bísaro (BI) breed. Specific slow type myosin heavy chain components were associated with AL (MYH7) and BI (MYH3) pigs, while an overexpression of MAP3K14 in AL may be associated with their lower loin proportion, induced insulin resistance, and increased inflammatory response via NFkB activation. Overexpression of RUFY1 in AL pigs may explain the higher intramuscular (IMF) content via higher GLUT4 recruitment and consequently higher glucose uptake that can be stored as fat. Several candidate genes for lipid metabolism, excluded in the RNA-seq analysis due to low counts, such as ACLY, ADIPOQ, ELOVL6, LEP and ME1 were identified by qPCR as main gene factors defining the processes that influence meat composition and quality. These results agree with the fatter profile of the AL pig breed and adiponectin resistance can be postulated as responsible for the overexpression of MAP3K140s coding product NIK, failing to restore insulin sensitivity
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