Mathematical Genesis of the Spatio-Temporal Covariance Functions

Obtaining new and flexible classes of nonseparable spatio-temporal covariances have resulted in a key point of research in the last years within the context of spatiotemporal Geostatistics. Approach: In general, the literature has focused on the problem of full symmetry and the problem of anisotropy has been overcome. Results: By exploring mathematical properties of positive definite functions and their close connection to covariance functions we are able to develop new spatio-temporal covariance models taking into account the problem of spatial anisotropy. Conclusion/Recommendations: The resulting structures are proved to have certain interesting mathematical properties, together with a considerable applicability.Spatial anisotropy, bernstein and complete monotone functions, spatio-temporal geostatistics, positive definite functions, space-time modeling, spatio-temporal data

Functionally graded concrete: Design objectives, production techniques and analysis methods for layered and continuously graded elements

The pressing need to reduce global carbon emissions together with recent advances in automated manufacturing have driven a growing interest in functionally graded concrete. In functionally graded concrete, the material composition is spatially varied to meet performance demands that differ within regions of a structural element. This offers significant potential to reduce cement consumption. Step-wise layered and continuously graded concrete systems are introduced and investigations of concrete mix combinations to achieve durability, fracture resistance, strength, ductility, cost saving, weight reduction or lower embodied energy improvements are discussed. Production techniques for horizontally layered and vertically layered structural elements in the context of fresh-on-hardened and fresh-on-fresh casting as well as emerging continuously graded processes are presented. Challenges associated with fresh-state deformations, layer interfaces and the need for appropriate fresh and hardened-state modelling tools are critically assessed.EPSRC - EP/N017668/

Novel transaminases from thermophiles: from discovery to application

Transaminases (TAs) are promising biocatalysts for chiral amine synthesis; however, only few thermophilic TAs have been described to date. In this work, a genome mining approach was taken to seek novel TAs from nine thermophilic microorganisms. TA sequences were identified from their respective genome sequences and their Pfam were predicted confirming that TAs class I–II are the most abundant (50%), followed by class III (26%), V (16%), IV (8%) and VI (1%). The percentage of open reading frames (ORFs) that are TAs ranges from 0.689% in Thermococcus litoralis to 0.424% in Sulfolobus solfataricus. A total of 94 putative TAs were successfully cloned and expressed into E. coli, showing mostly good expression levels when using a chemical chaperone media containing d-sorbitol. Kinetic and end-point colorimetric assays with different amino donors–acceptors confirmed TAs activity allowing for initial exploration of the substrate scope. Stereoselective and non-stereoselective serine-TAs were selected for the synthesis of hydroxypyruvate (HPA). Low HPA reaction yields were observed with four non-stereoselective serine-TAs, whilst two stereoselective serine-TAs showed significantly higher yields. Coupling serine-TA reactions to a transketolase to yield l-erythrulose (Ery) substantially increased serine conversion into HPA. Combining both stereoselective serine-TAs and transketolase using the inexpensive racemic D/L-serine led to high Ery yield (82%). Thermal characterization of stereoselective serine-TAs confirmed they have excellent thermostability up to 60°C and high optimum temperatures

The most influential countries in market orientation: A bibliometric analysis between 1990 and 2016

© The Author(s) 2018. The purpose of this article is to analyze the most productive and influential countries engaging in market orientation (MO) research between 1990 and 2016. This article shows the general trajectories of these countries, the relationships among them, and their research in the area of MO by analyzing results on citations and publications. The article uses applied bibliometric techniques on available information found in the Web of Science. The results show that the 10 leading countries produce more than 70% of total publications, where the United States leads in all indicators, followed by the United Kingdom and China. Furthermore, although there has been a steady increase in overall number of publications, this trend is not shared evenly among different nations

Motorized circular rail with RGB-D sensor on cart for physical rehabilitation

This paper introduces a motorized circular rail managing the movement of two carts equipped with an RGB-D sensor each. The proposal is aimed at continuously tracking a person who is undergoing a series of physical rehabilitation exercises from two different viewpoints to monitor if the exercises are being correctly conducted. More concretely, this work offers all details of the trajectory calculation for safe movement of both carts on the motorized circular rail. Then, two study cases are presented to show the efficiency of the control algorithms implemented.AEI - Agencia Estatal de Investigação(TIN2016-79100-R)This work was partially supported by Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación (AEI) / European Regional Development Fund (FEDER, UE) under DPI2016-80894-R and TIN2016-79100-R grants

LUGARES DE INTERÉS AGROECOLÓGICO COMO ESPACIO POTENCIAL PARA LA PRODUCCIÓN ECOLÓGICA

Traditional agroecosystems exhibit exceptional landscape, environmental and cultural values, which have been underestimated in agrarian and conservation policies, and in the society as well. Here we describe the current situation with our rich agrarian heritage, and the urgent needs for recovering and conservation. Strategies in the management of traditional agrobiodiversity are also discussed.Los agroecosistemas tradicionales poseen unos valores paisajísticos, ambientales y culturales excepcionales, que han sido a menudo menospreciados por las políticas agrarias y mediambientales, así como por la sociedad en general. En este artículo se expone la situación actual de nuestro rico patrimonio agrario, así como la necesidad de su recuperación y conservación. Finalmente, se presenta algunas estrategias de gestión y uso de la agrobiodiversidad tradicional

A novel image segmentation algorithm with applications on confocal microscopy analysis

Motivation: Developing cells change their gene expression profiles dynamically upon induction by proper triggers, typically diffusible morphogens that are spatially distributed (1). These changes impact cell cycle and apoptosis regulators differentially, eventually determining the final structure and size of the mature organs (2). A quantitative model that links gene regulation and tissue growth must be provided with precise experimental data at cell resolution level in order to proceed to its validation, which in some cases is essential for model screening (i.e. reverse ingineering methods). Image analysis from laser confocal microscopy (LCM) has already been used to address modelling problems in developmental tissues such as these (3). However current methods for LCM segmentation rely upon watershed algorithms that show variable efficiency, relatively high parametrization and oversegmentation problems that are critical on very aggregated objects (4). Here we present a different segmentation method based on the maximum complementary n-ball set (MCnB set) concept. The segmentation algorithm takes a full MCnB set as a starting graph representation of the whole stack, which is later contracted using a parallel implementation approach.Results: We assayed the performance by segmenting a randomly generated set of spheres with different resolutions, signal aggregation levels and densities, and compared to the results delivered by a common segmentation free software, (i.e. Vaa3D), which is based on watersheds (5). We also applied this comparison on DAPI stained samples from Drosophila eye-antenna imaginal discs. The results indicate that the mean square displacement of detected spheres centroids is higher in the 3D watershed implementation results than when our method is applied. The same results are obtained when the number of sets or their size are checked instead.Conclusions: The results indicate that our method is adequate enough for image segmentation in three dimensions. It makes no assumptions on what the shape or signal features of the objects are, and does not require any calibration since it can proceed with no specific user parameters. Moreover it beats at least one segmentation method that has already been set up for counting and segmentation. Since the shape of the voxel aggregates is not critical, we sugget that further implementations could be potentially applied in higher dimension samples with interesting applications in developmental biology (i.e. 4D 'movies' segmentation). However one major drawback is that at least one operation runs with a O(n^2) time complexity, which is time (and memory) consuming for very big images

Building Ontologies at the Knowledge Level using the Ontology Design Environment

This paper discusses how ontologies can be specified at the knowledge level using the set of intermediate representations (Gómez-Pérez, Fernández & de Vicente 1996) proposed by METHONTOLOGY (Fernández, Gómez-Pérez & Juristo 1997; and Gómez-Pérez 1998). These intermediate representations bridge the gap between how people think about a domain and the languages in which ontologies are formalized. Thus, METHONTOLOGY enables experts and ontology makers unfamiliar with implementation environments to build ontologies from scratch. In this paper, we also present the ODE (Ontology Design Environment) as a software tool to specify ontologies at the knowledge level. ODE allows developers to specify their ontology by filling in tables and drawing graphs. Its multilingual generator module automatically translates the specification of the ontology into target languages

Influence of S. cerevisiae and P. kluyveri as starters on chocolate flavour

"Published online in Wiley Online Library: 10 February 2021"BACKGROUND Fermented cocoa beans (Theobroma cacao L.) is a pivotal raw material for chocolate production. A cocktail yeast applied in the cocoa fermentation process can promote the formation of the pleasant metabolites. Saccharomyces, Pichia, and Hanseniaspora have been widely used in fermentation to improve the final product organoleptic profile. Highlighting that fermentation is a critical point for chocolate flavour precursors production. This study aims to evaluate the impact of Pichia kluyveri and Saccharomyces cerevisiae strains as starters cultures on the two cocoa hybrids fermentation FA13 and CEPEC2002. RESULTS During fermentation processes, volatile organic compounds (VOCs) and protein profiles were assessed. Chocolates produced were also assessed regarding the presence of VOCs. Eighty VOCs were identified by gas chromatography coupled to mass spectrometry analysis (HS-SPME GC-MS). Mass spectrometry by the MALDI-TOF technique provided the protein profiles evolution over fermentation and showed they changed with inoculation type (spontaneous vs. inoculated fermentation). Chocolate obtained by FA13 inoculated with S. cerevisiae strain contained higher organics acids amount, being categorised sourer than chocolate produced by spontaneous fermentation of FA13. CEPEC2002 inoculated with S. cerevisiae strain in co-culture with P. kluyveri strain generated less sour and sweeter chocolate than spontaneous fermentation only. CONCLUSION Chocolates from inoculated assays with starter cultures were more accepted by evaluators. Highlighting that P. kluyveri and S. cerevisiae influence the composition of VOCs. Besides, protein profiles also changed throughout fermentation. Further investigation should be conducted to clarify protein degradation dynamics during inoculated fermentations to defining which of both microbial cultures positively affect the chocolate sensory characteristics.The authors thank CNPq/Brazil, FAPEMIG/Brazil and CAPES/Brazil for scholarships, and Fazendas Reunidas Vale do Juliana (Bahia, Brazil). CS thanks Universidad de La Frontera/Chile for partial funding from Project PIA19-0001.info:eu-repo/semantics/publishedVersio