Effect of product that are used in postharvest in meiosis

Motivation: The meiosis is a type of cell division that generates the gametes necessary for the fertilisation. This process is more sensitive to external factors than mitosis. These agents can affect the exact chromosomes' distribution between daughter cells, and this defect causes infertility. It is known that some products that are used to conserve fruits and vegetables and to prevent postharvest's diseases, can generate defects in cell division, both mitosis and meiosis. In this project, we use Schizosaccharomyces pombe as meiosis model because it is an easy model system to grow and to manipulate in the laboratory. Also it has only three chromosomes, so we can find defects such as loss of chromosomes easily.Methods: We have created a S. pombe's strain with a CFP-tagged histone and a mCherry-tagged tubulin to can observe chromosomes and spindle by fluorescence. We have optimised the microscope's settings to observe correctly the meiosis in S. pombe.Results: We film the meiosis by fluorescence microscopy to observe the performance of chromosomes and spindle throughout this process (1). Initially, we cuantify the defects of meiosis in a wild type strain and we use this information as negative control of experiment. Then, we use carbendazim (MBC) as positive control of chromosomes' loss in meiosis. This is a fungicide that was used in postharvest (2) and it inhibits the polymerization of microtubules.  Finally, we observe the meiosis when we add to the culture other two products used in postharvest currently (3) (thiabendazole and fludioxonyl, among others), and we compare these results to the controls in order to indentify the products that causes defects in meiosis. In adition, we examine the defects in mitosis in the same conditions as meiosis to verify that meiosis is more sensitive than mitosis.Conclusion: The opmitization of microscope's settings has allowed to identify and to cuantify the errors that we have observed in chromosomes' distribution in meiosis

Strategies to improve the robustness of acentrosomal spindle formation in female meiosis

In meiosis, centrosomes are so important because they organize microtubules and nucleation of the spindle for a correct chromosomal segregation in eukaryotics cells. Human female oocytes lack centrosomes, so microtubules must self-assembly, which can cause mistakes in the process and diseases to the embryo. To study the molecular mechanisms supporting acentrosomal spindle, we are using the fission yeast Saccharomyces pombe as model scenario. In this organism, spindle pole bodies (SPBs), the functional equivalents of centrosomes, are sitting on the nuclear envelope (NE), which is dissasembled in each cell cycle by activating proteins like Sad1 and Bqt1, that mediate chromosome-NE contacts (Pineda-Santaella & Fernández-Álvarez, 2019). Based on these findings, our aims are making the acentrosomal spindle more robust and minimizing chromosomal segregation errors. In order to get then, we want to analyze the effects of overexpression of Cls1p, a cytoplasmic linker associated protein (CLASP) that stabilizes specific groups of MTs in S. pombe and has two homologous proteins in humans, CLASP1 and CLASP2. They contribute to the formation and maintenance of the spindle midzone by promoting MT rescue events (Al-Bassam et al., 2010). On the other hand, there are another important proteins in this process, like Klp6, a kind of kinesin-8, whose homologous proteins in humans are Kif18A, Kif18B, and Kif19. An in vivo study suggets that Klp6 binds to the tubulin triggering the birth of new MTs and promoting nucleation and catastrophe at the growing MT tip (Erent et al., 2012). Deletion or knockdown of Klp6 leads to longer spindles and defects in its assembly and position in many cases (Gergely et al., 2017), but we suggest that a longer acentrosomal spindle could also be stronger and more stable. So, we also pretend to observe the impact of deletion of klp6 on the spindle behavior and chromosome movements. To perform that experiments, we have obtained two different mutants for klp6 and cls1 in a bqt1Δ sad1.2 background by crossing some strains with these characteristics and we are studying what happens in the cell nucleus by fluorescent microscopy, using a DeltaVision microscope. As a result, we expect that chromosomal segregation in mutants for cls1 and klp6 will be more efficient with respect to the mutant control, which has only bqt1Δ sad1.2, and, ultimately, improve the meiotic process in this context

Reliability analysis based on non-dimensional parameters

A reliability analysis method is proposed that starts with the identification of all variables involved. These are divided in three groups: (a) variables fixed by codes, as loads and strength project values, and their corresponding partial safety coefficients, (b) geometric variables defining the dimension of the main elements involved, (c) the cost variables, including the possible damages caused by failure, (d) the random variables as loads, strength, etc., and (e)the variables defining the statistical model, as the family of distribution and its corresponding parameters. Once the variables are known, the II-theorem is used to obtain a minimum equivalent set of non-dimensional variables, which is used to define the limit states. This allows a reduction in the number of variables involved and a better understanding of their coupling effects. Two minimum cost criteria are used for selecting the project dimensions. One is based on a bounded-probability of failure, and the other on a total cost, including the damages of the possible failure. Finally, the method is illustrated by means of an application

Study of the Time-Temperature-Dependent behaviour of PVB: application to laminated glass elements

The mechanical behavior of laminated glass elements is governed by material properties of the interlayer, the Polyvinyl Butiral (PVB) being the most used interlayer material in these elements. PVB is a viscoelastic material whose mechanical properties (Young’s modulus, shear modulus, etc.) depend mainly on the load application time and the temperature. Thus an adequate mechanical characterization of the PVB must be performed in order to predict the response of laminated glass elements with a good accuracy In this work, PVB specimens were subjected to static relaxation tests and to dynamic experimental tests (frequency domain) at different temperatures from -〖15〗^o C to 〖50〗^o C using a DMTA equipment. Then the curves at different temperatures were related using the William-Landel-Ferry (WLF) Time-Temperature Superposition (TTS) model to obtain the mastercurve of both the time and frequency domain Young’s moduli of the PVB. Finally, a viscoelastic Prony based model was fitted to the experimental data and used, afterwards, to simulate numerically the static and dynamic behaviour of different laminated glass elements at different temperatures. The numerical simulations were compared with the static and dynamic experimental results achieving a good accuracy in both the static deflections and the natural frequencies. With respect to the damping, the discrepancies are less than 22%

Detection of metabolite changes in C6 glioma cells cultured with antimitotic oleyl glycoside by1H MAS NMR

The synthetic glycoside, oleyl N-acetyl-α-D-glucosaminide (1), was previously shown to exhibit antimitotic activity on rat (C6) and human (U-373) glioma lines. To obtain information about its mechanism of action, metabolite changes in C6 glioma cells were analyzed after treatment with 1 using high-resolution magic angle spinning 1H NMR. Compound 1 caused either a decrease or an increase in the intensity of the signal assigned to coenzyme A (CoA) metabolites depending on the concentration used. The data obtained from the 1H NMR spectra of cells cultured with 1, combined with those obtained after treatment with oleic acid (an inhibitor of acetyl-CoA carboxylase) and phenyl butyrate (a known antineoplastic agent), suggest that 1 may be altering the metabolism of fatty acids and induce apoptosis of C6 glioma cells. These results point to NMR spectroscopy as an efficient technique for monitoring the response of the cells to therapeutic agents.Peer Reviewe

EVALUACIÓN DE LA SATISFACCIÓN DE LOS USUARIOS EN INSTITUCIONES DE SALUD

La calidad de los servicios de salud cobra cada día mayor importancia, esun derecho de todos los seres humanos recibir atención médica y de alta calidad. En este escenario la satisfacción de los pacientes debe estar en el centro de atención de todos los servidores de salud y por tanto es una de las estrategias de gestión más importantes. El presente trabajo se realiza con la finalidad de evaluar la satisfacción de los pacientes con el servicio de hospitalización de una clínica integral. Se parte de elaborar el ciclo de losservicios y los momentos de la verdad para definir las principales insuficienciasque pueden presentarse cuando los pacientes entran en contacto con los empleados de la clínica y poder tomar decisiones acertadas. Además, se aplica un cuestionario que incluye los elementos tangibilidad, fiabilidad, capacidad de respuesta, seguridad y empatía a una muestra de 194 pacientes los cuales valoran de manera muy negativa los cinco atributos antes mencionados donde casi un 50% considera que sus percepciones son menores a las expectativas que poseían antes de ingresar a la clínica

Panorama da pesquisa em educação estatística desde teses doutorais 2000-2014

The article presents the formulation of categories aimed to review and classify doctoral theses according to their theoretical approaches, relevant topics in educational action, subjects or focus of interest, characterization of methodological principles and ideas about the teaching-learning of stochastics. The methodology mixes the hermeneutic qualitative paradigm with quantitative methods based on statistical counts. Results show the systematization of 129 theses with advisors from universities in 18 countries, their main theoretical approach being Literacy, reasoning  and statistical thinking. The qualitative paradigm is prioritized over the quantitative paradigm. The relevant focuses of interest are students from introductory courses in statistics and the disciplinary subject under study is descriptive statistics. Finally, the paper highlights the teaching of stochastics focused on real contexts in search of a critical education.En búsqueda de estrategias que posicionen de manera crítica la labor de grupos de investigación que trabajan en el campo de la educación estocástica4 (en especial la labor de la línea de Educación Estadística del grupo Didáctica de la Matemática de la UPN), se considera la elaboración de un panorama acerca de la investigación en dicho ámbito, como tarea que posibilita iniciar la reformulación de una agenda de trabajo investigativo afín con las tendencias actuales.La investigación inicia con la formulación de categorías que orientan la revisión y clasificación de tesis doctorales a la luz de enfoques teóricos, temas objeto de atención en la acción educativa, sujetos o focos de interés, caracterización de principios metodológicos que respaldan la indagación, e ideas acerca de la enseñanza-aprendizaje de la estocástica. La metodología de investigación del proyecto mezcla el paradigma cualitativo hermenéutico con métodos cuantitativos basados en recuentos estadísticos. El primero posibilita la acción interpretativa de las tesis, propicia la generación de categorías de análisis para su caracterización. Lo cuantitativo facilita la descripción de tendencias así como el afinamiento y la selección de una muestra de juicio de trece tesis.Entre los resultados se señala el acopio y la sistematización de 129 tesis asesoradas en universidades de 18 países. Se constata que el enfoque teórico “Alfabetización, razonamiento y pensamiento estadístico” es predominante y propio del campo. Respecto a las metodologías, la investigación cualitativa prima sobre la cuantitativa, y se reconoce el uso frecuente del “diseño de instrucción”. Los sujetos foco de interés investigativo más comunes son estudiantes de cursos introductorios de estadística, sin dejar de lado estudiantes de colegio y profesores de matemáticas (en formación inicial o continuada). En los temas disciplinares objeto de estudio, sobresale la estadística descriptiva sobre temas como la probabilidad, la inferencia y la variabilidad. Por último, se resalta la enseñanza de la estocástica centrada en contextos reales donde el aprendiz es el foco de atención en búsqueda de su formación crítica.O artigo apresenta a formulação de categorias orientadas à revisão e classificação de teses doutorais segundo suas abordagens teóricas, temas objeto de atenção na ação educativa, sujeitos ou focos de interesse, caracterização de princípios metodológicos e ideias acerca do ensino e a aprendizagem da estocástica. A metodologia mistura o paradigma qualitativo hermenêutico com métodos quantitativos baseados nas contagens estatísticas. Os resultados mostram a sistematização de 129 teses assessoradas em universidades de 18 países. Sua abordagem teórica predominante é a Alfabetização, Razoamento e Pensamento Estatístico. Existe uma priorização do paradigma qualitativo sobre o quantitativo. Os sujeitos alvo são estudantes de classes introdutórias de estatística e o tema disciplinar objeto de estudo sobressaliente é a estatística descritiva. Finalmente, ressalta-se o ensino da estocástica centrada em contextos reais, procurando uma formação de tipo crítico

Low density Porcicoll separates spermatozoa from bacteria and retains sperm quality

[EN] Antibiotics are added to semen extenders to control the growth of bacteria contaminating semen during collection but may contribute to the development of antibiotic resistance. An alternative would be physical separation of spermatozoa from bacteria. The objective of the present study was to evaluate two low densities of Porcicoll for removal of bacteria, and for their effect on sperm recovery and sperm quality. Semen was collected from boars at a commercial station. Aliquots of 8 extended ejaculates were subjected to colloid centrifugation through 20% Porcicoll (P20) and 30% Porcicoll (P30) in 500 mL tubes and then stored at 17 °C. Microbiological examination and sperm quality evaluation (computer assisted sperm analysis and flow cytometry) were carried out on controls and all colloid-selected samples immediately after preparation and again after storage for 3 and 7 days. The microorganisms found were mainly bacteria from the environment, gut or skin. There was a considerable reduction or complete removal of some bacteria by both colloids. Recovery rates were 86% for P20 and 81% for P30. Sperm quality was not adversely affected by colloid centrifugation on day 0, and thereafter showed a more gradual deterioration in colloid centrifuged samples than in controls, possibly due to lower bacterial contamination. There were no differences in sperm quality between the two colloid treatments. Thus, these results show that contaminating bacteria in semen can be controlled by centrifugation through low density colloidsSIThis work was funded by a pump grant from the Society for Reproduction and Fertility, UK, to JMM and by grants to FMP (RTI2018-095183-B-I00, MCI/AEI/FEDER, EU, and LE023P20, Junta de Castilla y León/Consejería de Educación/FEDER, EU

Linkage-research integration in the Medicine degree at the Universidad Regional Autónoma de Los Andes

Introduction: the integration of scientific research and linkage is key for the contribution of universities to the solution of society's problems through the transfer of knowledge and innovation. Objective: characterize the integration process between linkage and research in the UNIANDES Medicine degree. Method: a predominantly qualitative and descriptive research was carried out with the use of documentary analysis and interviews. Governing documents, guidelines, and policies applied in the Medicine career were reviewed. Interviews were carried out with the coordinators in the program to search for volume of information about these two activities and the specific projections of mainstreaming. Results: a weakness was noted in terms of the management of the link with society, absence of a broader vision of comprehensive management where not only linkage with teaching is intertwined in pre-professional practices but also in integrative projects and the existence of will of institutional directors to create a true university-society link through research. Conclusions: a broader vision of the integration between the three key university processes is missing, only the relationship between teaching and connection is evident from pre-professional practices, leaving out the basis and genesis that knowledge-integrating projects should be. In order to perfect this integration, social innovation projects must be proposed where linkage and research come together, guaranteeing the publication of the results of social innovation projects in the internal journals of UNIANDES and in others with regional or global impact

Mutations in a histone H2A variant with implications for fertility

Meiosis is a process of cell division in which an organism reproduces sexually by replicating its genetic material followed bytwo successive cell divisions, resulting in the formation of four haploid products (Foulis, S.J. et al., 2018). In this way, theorganization of chromatin plays an important role in the process of cell division, in which the variant of histone H2A, the histoneH2A.Z, has been proposed as a possible candidate related to the role of chromatin in meiosis (Shintaro Yamada et al., 2018).The function of this histone variant has been observed in Saccharomyces cerevisiae, in which it has been shown that it mayhave some implication in nuclear movements. Specifically, its relationship with components of the LINC complex has beenobserved, suggesting that they act as an additional factor associated with this complex, participating in its dynamics andtherefore contributing to the chromosomal movement essential for gametogenesis (González-Arranz, S. et al., 2020). In thiscontext, in this study we wanted to develop a more precise methodology hat allows us to study the implication of this protein incell division. To do this, we have used the model organism Schizosaccharomyces pombe because the nuclear movements aremore drastic than S. cerevisiae and therefore it is easier to observe small differences than in wild strains. On the other hand,by fluorescence microscopy (DeltaVision) it is possible to observe these small variations more easily. In this way, we will beable to carry out a more exhaustive study about the participation of the histone H2A.Z and know its implication in chromosomalmovement