172 research outputs found
Modelización de la distribución espacial de quistes en el estómago de la marsopa mediante un proceso de Gibbs
First records of genus Dilyta from Madagascar with description of Dilyta paretasmartinezi n. sp. (Hymenoptera: Figitidae: Charipinae)
Es cita per primera vegada el gènere Dilyta de Madagascar. Han estat col·lectades dues espècies: D. subclavata Förster, 1869 and D. paretasmartinezi n. sp. La nova espècie que aquí es descriu presenta una carena a l’àpex de l’escutel·le en forma de ∩, la qual cosa diferencia aquesta nova espècie de la resta d’espècies africanes del gènere Dilyta. Les característiques morfològiques i els caràcters diagnòstics es discuteixen i s’il·lustren.The genus Dilyta is mentioned from Madagascar for the first time. Two species have been collected: D. subclavata Förster, 1869 and D. paretasmartinezi n. sp. The new species has ∩-shaped carinae at the apex of scutellum which differentiate it from the African Dilyta species. Its morphological features and diagnostic characters are discussed and illustrated
Revision of the Charipinae species present in India with some taxonomic changes (Hymenoptera: Cynipoidea, Figitidae, Charipinae)
Charipinae species present in India are revised and taxonomic changes are proposed for some species recently described from this country. In total seven species are nowadays valid from India: Alloxysta brevis (Thomson, 1862), A. consobrina (Zetterstedt, 1838), A. nottoni Ferrer-Suay & Pujade-Villar, 2015, A. pleuralis (Cameron, 1879), Phaenoglyphis indica Ferrer-Suay & Pujade-Villar, 2013, P. longicornis (Hartig, 1840) and P. villosa (Hartig, 1841). Alloxysta ochracea Bijoy & Rajmohana, 2013, is a new synonymy of A. brevis (Thomson, 1862). Alloxysta bhagyae Bijoy & Rajmohana, 2013, A. indica Bijoy & Rajmohana, 2013, and A. sholicola Bijoy & Rajmohana, 2013 are new synonymies of A. consobrina (Zetterstedt, 1838). Comments and figures are included here to support these taxonomic changes. Diagnosis for these species and a key to identify the Charipinae from India is also incorporated
Intraspecific variation in the morphology of Alloxysta fracticornis (Thomson, 1862) (Hymenoptera: Figitidae: Charipinae).
A new brachypterous form of Alloxysta fracticornis (Thomson, 1862) has been found in the Museum of Natural History of Wroclaw University (Poland). This is the first time that this morphological variation has been recorded for A. fracticornis. The morphological features of this new form match with this species, except for the wing length, which is characteristic of the brachypterous form, and the colour. COI sequences and phylogenetic analysis for the specimens studied (macropterous and brachypterous) confirm that the two morphologies belong to the same species, as we suspected a priori. Thus, in this study we show evidence of morphological variation in A. fracticornis, and demonstrate the value of studying entomological collections as well as new material to improve the taxonomic knowledge of this subfamily
Study of the thermal degradation of bioactive sol-gel coatings for the optimization of its curing process
A set of materials has been prepared by sol-gel process containing different quantities of hydroxyapatite (0, 2.5 and 5% HAp w/w) using as silica precursors glycidyloxypropyltrimethoxysilane (GPTMS) and triethoxyvinylsilane (VTES). In order to optimize the curing process to obtain sintherized systems (inorganic network) or hybrid systems (organic&-inorganic) a TG and FTIR studies have been developed and degradation kinetic triplet parameters were obtained (the activation energy, pre-exponential factor, and function of degree of conversion). The kinetic study was analyzed by means of an integral isoconversional non-isothermal procedure (model free), and the kinetic model was determined by the Coats&-Redfern method and through the compensation effect (IKR). All the systems followed the n = 6 kinetic model. The addition of HAp increases the thermal stability of the systems. The isothermal degradation was simulated from non-isothermal data, and the curing process could be defined to obtain the two types of materials. Temperature under 250 °C allows the formation of hybrids networks.Publicad
Kernel Methods and their derivatives: Concept and perspectives for the Earth system sciences
Kernel methods are powerful machine learning techniques which implement
generic non-linear functions to solve complex tasks in a simple way. They Have
a solid mathematical background and exhibit excellent performance in practice.
However, kernel machines are still considered black-box models as the feature
mapping is not directly accessible and difficult to interpret.The aim of this
work is to show that it is indeed possible to interpret the functions learned
by various kernel methods is intuitive despite their complexity. Specifically,
we show that derivatives of these functions have a simple mathematical
formulation, are easy to compute, and can be applied to many different
problems. We note that model function derivatives in kernel machines is
proportional to the kernel function derivative. We provide the explicit
analytic form of the first and second derivatives of the most common kernel
functions with regard to the inputs as well as generic formulas to compute
higher order derivatives. We use them to analyze the most used supervised and
unsupervised kernel learning methods: Gaussian Processes for regression,
Support Vector Machines for classification, Kernel Entropy Component Analysis
for density estimation, and the Hilbert-Schmidt Independence Criterion for
estimating the dependency between random variables. For all cases we expressed
the derivative of the learned function as a linear combination of the kernel
function derivative. Moreover we provide intuitive explanations through
illustrative toy examples and show how to improve the interpretation of real
applications in the context of spatiotemporal Earth system data cubes. This
work reflects on the observation that function derivatives may play a crucial
role in kernel methods analysis and understanding.Comment: 21 pages, 10 figures, PLOS One Journa
Design of nanostructured siloxane-gelatin coatings: Immobilization strategies and dissolution properties
Owing to the outstanding service life of metallic prostheses, a substantial effort has been put into their surface modification to improve biocompatibility and reduce metallic ion diffusion. To satisfy these requirements, the coating materials obtained using the sol-gel method, with its wide range of tuning properties, have been extensively explored. The well-known biocompatibility of these materials makes them good candidates for different biomedical applications. We designed a series of siloxane-gelatin hybrids to be used as coatings for metallic implants or in controlled delivery systems. Two different matrixes were designed based on methyltrimethoxysilane (MTMOS), tetraethoxysilane (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) alkoxysilane precursors. In one hybrid coating gelatin was physically entrapped and in the other it was linked to the siloxane network by covalent bonds. Synthesis parameters were established by studying the sol-gel reaction using 29Si nuclear magnetic resonance (29Si NMR), which also allowed quantification of the network connectivity. Dissolution and degradation studies showed the effectiveness of GPTMS as a covalent coupling agent between the silica and gelatin phases; it increased the stability of the coatings in aqueous media. The aim of this study was to design a set of hybrid materials with highly tailorable properties, suitable for their potential biomedical application
Testosterona y evaluación de la conducta agresiva en jóvenes judokas
En un grupo de jóvenes judokas (15 a 22 años), se analizan las relaciones entre los andrógenos y la conducta agresiva evaluada por dos instrumentos: un autoinforme y un cuestionario cumplimentado por los entrenadores, que presenta correlaciones más consistentes con los valores hormonales. En la muestra estudiada, las relaciones entre hormonas y conducta agresiva son más evidentes entre los sujetos de mayor edad que entre los adolescentes. Este aumento de la conducta agresiva está significativamente relacionado con la edad y con los años de práctica del Judo. Los sujetos de alto nivel competitivo obtienen puntuaciones significativamente mayores que los de nivel más bajo, sugiriendo la influencia de la actividad competitiva sobre la conducta agresivaRelationships between androgenic hormones and aggressive behavior are analysed in young judoists (15-22 years). Aggressive behavior has been assessed by two means: a self-report inventory and a scale answered by the subjects' coaches. This scale shows more consistent correlations with hormonal values. In our subjects, these relations are stronger in older than in younger subjects. The increase in aggressive behavior is significantly related to the age and also to the time of judo practice. High-level competitors obtain significantly higher scores than low-level subjects, suggesting the influence of competition on aggressive behavio
The design and characterisation of sol–gel coatings for the controlled-release of active molecules
The controlled release of active agents from a matrix has become increasingly important for oral, transdermal or implantable therapeutic systems, due to the advantages of safety, efficacy and patient convenience. Controlled-release hybrid (organic-inorganic) sol-gel coating synthesis has been performed to create a sol with an active molecule included (procaine). Synthesis procedures included acid-catalysed hydrolysis, sol preparation, the addition of a procaine solution to the sol, and the subsequent gelation and drying. The alkoxide precursors used were triethoxyvinylsilane and tetraethyl-orthosilicate (TEOS) in molar ratios of 1:0, 9:1, 8:2 and 7:3. After the determination of the optimal synthesis parameters, the material was physicochemically characterised by silicon-29 nuclear magnetic resonance (²⁹Si-NMR) and Fourier transform infrared spectroscopy, contact angle analysis and electrochemical impedance spectroscopy tests. Finally, the materials were assayed in vitro for their ability to degrade by hydrolysis and to release procaine in a controlled manner. The sustained release of procaine over a 3-day period was demonstrated. A close correlation between release and degradation rates suggests that film degradation is the main mechanism underlying the control of release. Electrochemical analysis reveals the formation of pores and water uptake during the degradation. The quantity of TEOS is one of the principal parameters used to determine the kinetics of degradation and procaine release.The supports of the Spanish Ministry of Economy and Competitiveness through project IPT-010000-2010-004 and of the University of the Basque Country (UPV/EHU) through ‘‘UFI11/56’’ are kindly acknowledge
Control of the degradation of silica sol-gel hybrid coatings for metal implants prepared by the triple combination of alkoxysilanes
Hybrid materials obtained by sol-gel process are able to degrade and release Si compounds that are useful in regenerative medicine due to their osteoinductive properties. The present work studies the behavior of new organic-inorganic sol-gel coatings based on triple mixtures of alkoxysilanes in different molar ratios. The precursors employed are methyl-trimethoxysilane (MTMOS), 3-glycidoxypropyl-trimethoxysilane (GPTMS) and tetraethyl-orthosilicate (TEOS). After optimization of the synthesis conditions, the coatings were characterized using 29Si nuclear magnetic resonance (29Si-MNR), Fourier transform infrared spectrometry (FT-IR), contact angle measurements, hydrolytic degradation assays, electrochemical impedance spectroscopy (EIS) and mechanical profilometry. The degradation and EIS results show that by controlling the amount of TEOS precursor in the coating it is possible to tune its degradation by hydrolysis, while keeping properties such as wettability at their optimum values for biomaterials application. The corrosion properties of the new coatings were also evaluated when applied to stainless steel substrate. The coatings showed an improvement of the anticorrosive properties of the steel which is important to protect the metal implants at the early stages of the regeneration process.The financial support of MAT2014-51918-C2-2-R, P11B2014-19 and Plan de Promoción de la Investigación from the Universitat Jaume I (Predoc/2014/25) is gratefully acknowledged. J. García-Cañadas acknowledge financial support from Ramón y Cajal programme (RYC-2013-13970). The experimental support of Raquel Oliver Valls and José Ortega Herreros is also acknowledged
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