Human oocytes and zygotes are ready for ultra-fast vitrification after 2 minutes of exposure to standard CPA solutions

Vitrification of human oocytes and embryos in different stages of development is a key element of daily clinical practice of in vitro fertilization treatments. Despite the cooling and warming of the cells is ultra-fast, the procedure as a whole is time consuming. Most of the duration is employed in a long (8–15 minutes), gradual or direct exposure to a non-vitrifying cryoprotectant solution, which is followed by a short exposure to a more concentrated vitrifying solution. A reduction in the duration of the protocols is desirable to improve the workflow in the IVF setting and reduce the time of exposure to suboptimal temperature and osmolarity, as well as potentially toxic cryoprotectants. In this work it is shown that this reduction is feasible. In silico (MatLab program using two-parameter permeability model) and in vitro observations of the oocytes’ osmotic behaviour indicate that the dehydration upon exposure to standard cryoprotectant solutions occurs very fast: the point of minimum volume of the shrink-swell curve is reached within 60 seconds. At that point, intracellular water ejection is complete, which coupled with the permeation of low molecular weight cryoprotectants results in similar intracellular and extracellular solute concentrations. This shows that prolonging the exposure to the cryoprotectant solutions does not improve the cytosolic glass forming tendency and could be avoided. To test this finding, human oocytes and zygotes that were donated for research were subjected to a shortened, dehydration-based protocol, consisting of two consecutive exposures of one-minute to two standard cryoprotectant solutions, containing ethylene glycol, dimethyl sulfoxide and sucrose. At the end of this two-minute dehydration protocol, the critical intracellular solute concentration necessary for successful vitrification was attained, confirmed by the post-warming survival and ability to resume cytokinesis of the cells. Further studies of the developmental competency of oocytes and embryos would be necessary to determine the suitability of this specific dehydration protocol for clinical practice, but based on our results, short times of exposure to increasingly hypertonic solutions could be a more time-efficient strategy to prepare human oocytes and embryos for vitrification

The relationship between height and economic development in Spain. A historical perspective

This paper investigates the relationship between height and economic development in Spain in the modern period. The relation is investigated using recently constructed times series with recruitment data of conscripts. We observed changes in average height along the analyzed period. These variations could be explained by different indicators of economic development such as consumption of hygiene products, the deflator of private consumption, income per capìta, schooling rate, infant mortality and trade (degree of openness). We model human stature as a Vector Autoregressive Model (VAR) and we proceed to estimate a Vector Autoregressive Equilibrium Correction Model (VECqM) to quantify the height response to different changes in the different explanatory variables. The analysis shows that there is a long-°©‐run relationship between height, income, and other indicators of economic development in Spain as consumption of hygiene products, and the degree of opennessHeight, health, income, education, economic development, cointegration, Spain.

The internationalization of the educational problems and the homogenization of educational reforms further than Latin América: The case of Mozambique

Mozambique inicia en 1992 un proceso de reformas educativas que suponen un cambio de paradigma desde las tesis socialistas al planteamiento educativo neoliberal. Esta opción ha permitido acceder a la ayuda de los donantes e iniciar el camino de reconstrucción post-bélica tras años de guerra civil. La política educativa ha adoptado desde entonces los planteamientos pedagógicos, organizativos y curriculares que emanan de los organismos de Naciones Unidas y del Banco Mundial. Los progresos en estas metas, sin embargo, no pueden ocultar la dificultad para conseguir una educación pertinente y equitativa que permita la promoción social de los colectivos más vulnerables. Este artículo argumenta la falacia de un modelo educativo que sirve más para legitimar y dar credibilidad a las autoridades ante la comunidad internacional que para promover el desarrollo social, y plantea que el cambio hacia políticas educativas inclusivas y participativas sólo será posible desde el fortalecimiento de la sociedad civilMozambique began in 1992 a process of educational reforms that represents a paradigm shift from socialist theses to a neo-liberal approach to education. That option has enabled access to the support of donors and begin the path of post-war reconstruction after years of civil war. Since then, education policy has adopted the pedagogical, organizational and curricular approaches emanating from agencies of the United Nations and the World Bank. However, progress on these goals cannot hide the difficulty to achieve an appropriate and equitable education that allows the social promotion of the most vulnerable groups. This paper argues the fallacy of an educational model that serves more to legitimize and give credibility to the authorities before the international community that to promote social development, and shows that the shift to inclusive and participatory educational policies will only be possible with the strengthening of civil societ

Nueva antena de ranuras axiales sobre superficie cilíndrica alimentadas desde guías sectoriales

Se estudia un nuevo tipo de alimentador para los arrays de ranuras axiales sobre cilindros conductores. Este tipo de antenas es adecuado para su utilización en radioboyas repetidores de TV FM y en todas las aplicaciones que requieran cobertura omnidireccional o selectiva en el plano acimutal. Se analizan las características de dichas antenas y se desarrolla un nuevo método de alimentación basado en la división del espacio interior del cilindro en guías sectoriales. Se realiza un modelo que se compara con los resultados obtenidos experimentalmente dando como resultado un compromiso adecuado entre complejidad analítica y cálculo

Embarcaciones de pesca en Castro Urdiales: de las chalupas y pinazas a las lanchas y traineras (1550-1890)

Comunicación, inscrita dentro de un proyecto más amplio de investigación sobre el sector pesquero tradicional de Castro Urdiales, en la que se hace un seguimiento bajo parámetros históricos de las embarcaciones dedicadas a la pesca desde el siglo XVI a finales del XIX.Castro Urdialesko arrantza sektore tradizionalari buruzko ikerketa proiektu zabalago baten barnean kokatzen da komunikazio hau. Bertan, XVI. mendetik XIX.aren amaiera artean arrantzari ekiten zioten ontzien jarraipena egiten da parametro historikoen ikuspegitik.Communication, inscrite au sein d'un projet plus vaste de recherche sur le secteur de la pêche traditionnelle de Castro Urdiales, dans laquelle on fait un suivi sous des paramètres historiques des embarcations consacrées à la pêche depuis le XVIème siècle jusqu'à la fin du XIXème.This conference was framed within a wider research project on the traditional fishing sector in Castro Urdiales. This study carries out a follow-up under historical parameters of the vessels dedicated to fishing as from the 16th century to the late 19th century

Attitudes expressed in online comments about environmental factors in the tourism sector: an exploratory study

The object of this exploratory study is to identify the positive, neutral and negative environment factors that affect users who visit Spanish hotels in order to help the hotel managers decide how to improve the quality of the services provided. To carry out the research a Sentiment Analysis was initially performed, grouping the sample of tweets (n = 14459) according to the feelings shown and then a textual analysis was used to identify the key environment factors in these feelings using the qualitative analysis software Nvivo (QSR International, Melbourne, Australia). The results of the exploratory study present the key environment factors that affect the users experience when visiting hotels in Spain, such as actions that support local traditions and products, the maintenance of rural areas respecting the local environment and nature, or respecting air quality in the areas where hotels have facilities and offer services. The conclusions of the research can help hotels improve their services and the impact on the environment, as well as improving the visitors experience based on the positive, neutral and negative environment factors which the visitors themselves identified

Microscopic Model for Sequential Tunneling in Semiconductor Multiple Quantum Wells

We propose a selfconsistent microscopic model of vertical sequential tunneling through a multi-quantum well.The model includes a detailed description of the contacts,uses the Transfer Hamiltonian for expressions of the current and it treats the Coulomb interaction within a mean field approximation. We analyze the current density through a double well and a superlattice and study the formation of electric field domains and multistability coming from the Coulomb interaction. Phase diagrams of parameter regions (bias, doping in the heterostructure and in the contacts,etc) where the different solutions exist are given.Comment: 4 pages, 8 Postscript Figure