Positional dependence of transcriptional inhibition by DNA torsional stress in yeast chromosomes

How DNA helical tension is constrained along the linear chromosomes of eukaryotic cells is poorly understood. In this study, we induced the accumulation of DNA (+) helical tension in Saccharomyces cerevisiae cells and examined how DNA transcription was affected along yeast chromosomes. The results revealed that, whereas the overwinding of DNA produced a general impairment of transcription initiation, genes situated at <100 kb from the chromosomal ends gradually escaped from the transcription stall. This novel positional effect seemed to be a simple function of the gene distance to the telomere: It occurred evenly in all 32 chromosome extremities and was independent of the atypical structure and transcription activity of subtelomeric chromatin. These results suggest that DNA helical tension dissipates at chromosomal ends and, therefore, provides a functional indication that yeast chromosome extremities are topologically open. The gradual escape from the transcription stall along the chromosomal flanks also indicates that friction restrictions to DNA twist diffusion, rather than tight topological boundaries, might suffice to confine DNA helical tension along eukaryotic chromatin

Eficacia de la colchicina en pacientes con COVID-19: una revisión narrativa

La COVID-19 ha causado millones de muertes en todo el mundo en poco más de un año. Aunque no se conocen por completo los mecanismos implicados, diversos estudios han reportado un gran componente inflamatorio, con subsecuente liberación descontrolada de citocinas (tormenta de citocinas). La falta de terapias específicas probadas contra esta enfermedad, ha llevado a evaluar la utilidad de medicamentos seguros, de fácil acceso, y con efecto antiinflamatorio como la colchicina. Realizamos una revisión narrativa sobre la eficacia de la colchicina sobre los principales resultados clínicos adversos en pacientes con COVID-19. Incluimos 13 estudios publicados recientemente en las principales bases de datos. Concluimos que, en pacientes con COVID-19 no hospitalizados, la colchicina podría reducir la mortalidad, el riesgo de requerir hospitalización y ventilación mecánica. Mientras que, en pacientes hospitalizados con COVID-19, la colchicina no se asocia con reducción de la mortalidad, necesidad de ventilación mecánica, ni de la duración de la estancia hospitalaria. Tampoco se ha demostrado que la colchicina tenga un rol “profiláctico”

Eficacia de la colchicina en pacientes con COVID-19: una revisión narrativa

COVID-19 has caused millions of deaths worldwide in just over a year. Although the mechanisms involved are not fully understood, several studies have reported a large inflammatory component, with subsequent uncontrolled release of cytokines (cytokine storm). The lack of specific proven therapies against this disease has led to the evaluation of the usefulness of safe and easily accessible drugs with an anti-inflammatory effect such as colchicine. We conducted a narrative review of the efficacy of colchicine on the main adverse clinical outcomes in patients with COVID-19. We include 13 recently published studies in the main databases. We conclude that, in non-hospitalized COVID-19 patients, colchicine could reduce mortality, the risk of requiring hospitalization and mechanical ventilation. While, in hospitalized patients with COVID-19, colchicine is not associated with a reduction in mortality, the need for mechanical ventilation, or the length of hospital stay. Neither has colchicine been shown to have a “prophylactic” role.La COVID-19 ha causado millones de muertes en todo el mundo en poco más de un año. Aunque no se conocen por completo los mecanismos implicados, diversos estudios han reportado un gran componente inflamatorio, con subsecuente liberación descontrolada de citocinas (tormenta de citocinas). La falta de terapias específicas probadas contra esta enfermedad, ha llevado a evaluar la utilidad de medicamentos seguros, de fácil acceso, y con efecto antiinflamatorio como la colchicina. Realizamos una revisión narrativa sobre la eficacia de la colchicina sobre los principales resultados clínicos adversos en pacientes con COVID-19. Incluimos 13 estudios publicados recientemente en las principales bases de datos. Concluimos que, en pacientes con COVID-19 no hospitalizados, la colchicina podría reducir la mortalidad, el riesgo de requerir hospitalización y ventilación mecánica. Mientras que, en pacientes hospitalizados con COVID-19, la colchicina no se asocia con reducción de la mortalidad, necesidad de ventilación mecánica, ni de la duración de la estancia hospitalaria. Tampoco se ha demostrado que la colchicina tenga un rol “profiláctico”

Preliminary results of the risk perception of radon exposure

The Council Directive 2013/59/Euratom regulates radon exposures in dwellings for the first time in the European Union. It establishes that Member States, to address long-term risks from radon exposures in dwellings, buildings with public access and workplaces for any source of radon ingress, shall establish a national action plan considering the issues set out in Annex XVIII. Member States shall increase public awareness about indoor radon risk, the importance of carrying out indoor radon concentration measurements and the availability of radon concentration reduction techniques. In this paper we present preliminary data, collected in the district of Naples (Italy), on the public’s knowledge regarding the risks associated with exposure to radon. The collected data, based on a specifically designed questionnaire, provide some points of reflection both for the optimization of the questionnaire itself, for future surveys, and for the information program for the population

Técnicas de electrónica de potencia para el electroaturdimiento y electrosacrificio, en el sector del atún rojo

Las técnicas de electropesca utilizadas en agua dulce han sido adaptadas a la explotación industrial de la pesca en agua salada de especies como el atún rojo. Por desgracia, como consecuencia de las descargas eléctricas aplicadas, a través de un arpón, se producen daños en la espina que disminuyen la calidad del producto. Se describe aquí un proyecto que aborda el desarrollo de un convertidor electrónico de potencia, versátil y que permite estudiar diferentes formas de onda y su efecto sobre la calidad del producto.Ginés Méndez España S.L

Informe preliminar sobre la prospección de la Vall del Barxell -Polop (Alcoi-Alcant)

Dins del projecte d'estudi del procés de neolitització a les comarques centromeridionals del País Valencià. es presenten els resultats preliminars obringuts en la prospecció sistemàtica deI la capçalera del riu Serpis, la Vall de Barxell-Polop (Alcoi-Alacant).Within the survey project of neolithization in the central and southern regions of the Valencian Country, we present herein the preliminary results achieved so far in the systematic prospecting at the source of the Serpis River, located in the Barxell-Polop Valley, within the municipal boundary of Alcoi, in the Alicante area.Dentro del proyecto de estudio del proceso de Neolitización en las comarcas centromeridionales del País Valenciano. se presentan los resultados preliminares obtenidos en la prospección sistemática de la cabecera del río Serpis, valle del Barxell-Polop (Alcoi. Alacant)

Mesoscopic structure conditions the emergence of cooperation on social networks

We study the evolutionary Prisoner's Dilemma on two social networks obtained from actual relational data. We find very different cooperation levels on each of them that can not be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community structure of the networks. We explain the dependence of the cooperation level on the temptation parameter in terms of the internal structure of the communities and their interconnections. We then test our results on community-structured, specifically designed artificial networks, finding perfect agreement with the observations in the real networks. Our results support the conclusion that studies of evolutionary games on model networks and their interpretation in terms of global properties may not be sufficient to study specific, real social systems. In addition, the community perspective may be helpful to interpret the origin and behavior of existing networks as well as to design structures that show resilient cooperative behavior.Comment: Largely improved version, includes an artificial network model that fully confirms the explanation of the results in terms of inter- and intra-community structur

Preliminary trials on the development of electroslaughtering and electrostunning techniques for bluefin tuna Thunnus thynnus (L., 1758) reared in floating cages

Preliminary results are presented from an ongoing study concerning the relationship between the type of electrical waves used to slaughter bluefin tuna Thunnus thynnus (L., 1758) ongrown in floating cages, and damage to the dorsal column and fish meat, which reduces the fish's commercial value on the Japanese market. Our results indicate that varying the waves' characteristics can reduce those undesirable effects, making this technique the most suitable for bluefin tuna slaughtering, in order to obtain superior meat quality.Se presentan los resultados preliminares del estudio que se lleva a cabo sobre la relación existente entre el tipo de onda eléctrica utilizada para el electrosacrificio del atún rojo Thunnus thynnus (L., 1758), engordado en jaulas flotantes, y los daños producidos en la espina dorsal y la carne de los ejemplares de esta especie, que reducen su valor comercial en el mercado japonés. Se ha observado que se puede mitigar estos efectos indeseados variando las características de las ondas empleadas, haciendo de esta técnica la más apropiada en el sacrificio del atún para obtener una carne de calidad superior.Instituto Español de OceanografíaVersión del editor

Resolution of the stochastic strategy spatial prisoner's dilemma by means of particle swarm optimization

We study the evolution of cooperation among selfish individuals in the stochastic strategy spatial prisoner's dilemma game. We equip players with the particle swarm optimization technique, and find that it may lead to highly cooperative states even if the temptations to defect are strong. The concept of particle swarm optimization was originally introduced within a simple model of social dynamics that can describe the formation of a swarm, i.e., analogous to a swarm of bees searching for a food source. Essentially, particle swarm optimization foresees changes in the velocity profile of each player, such that the best locations are targeted and eventually occupied. In our case, each player keeps track of the highest payoff attained within a local topological neighborhood and its individual highest payoff. Thus, players make use of their own memory that keeps score of the most profitable strategy in previous actions, as well as use of the knowledge gained by the swarm as a whole, to find the best available strategy for themselves and the society. Following extensive simulations of this setup, we find a significant increase in the level of cooperation for a wide range of parameters, and also a full resolution of the prisoner's dilemma. We also demonstrate extreme efficiency of the optimization algorithm when dealing with environments that strongly favor the proliferation of defection, which in turn suggests that swarming could be an important phenomenon by means of which cooperation can be sustained even under highly unfavorable conditions. We thus present an alternative way of understanding the evolution of cooperative behavior and its ubiquitous presence in nature, and we hope that this study will be inspirational for future efforts aimed in this direction.Comment: 12 pages, 4 figures; accepted for publication in PLoS ON

Detrimental Effects of Non-Functional Spermatozoa on the Freezability of Functional Spermatozoa from Boar Ejaculate

In the present study, the impact of non-functional spermatozoa on the cryopreservation success of functional boar spermatozoa was evaluated. Fifteen sperm-rich ejaculate fractions collected from five fertile boars were frozen with different proportions of induced non-functional sperm (0 –native semen sample-, 25, 50 and 75% non-functional spermatozoa). After thawing, the recovery of motile and viable spermatozoa was assessed, and the functional of the spermatozoa was evaluated from plasma membrane fluidity and intracellular reactive oxygen species (ROS) generation upon exposure to capacitation conditions. In addition, the lipid peroxidation of the plasma membrane was assessed by the indirect measurement of malondialdehyde (MDA) generation. The normalized (with respect to a native semen sample) sperm motility (assessed by CASA) and viability (cytometrically assessed after staining with Hoechst 33342, propidium iodide and fluorescein-conjugated peanut agglutinin) decreased (p<0.01) as the proportion of functional spermatozoa in the semen samples before freezing decreased, irrespective of the semen donor. However, the magnitude of the effect differed (p<0.01) among boars. Moreover, semen samples with the largest non-functional sperm subpopulation before freezing showed the highest (p<0.01) levels of MDA after thawing. The thawed viable spermatozoa of semen samples with a high proportion of non-functional spermatozoa before freezing were also functionally different from those of samples with a low proportion of non-functional spermatozoa. These differences consisted of higher (p<0.01) levels of intracellular ROS generation (assessed with 5-(and-6) chloromethyl-20,70-dichlorodihydrofluorescein diacetate acetyl ester; CM-H2DCFDA) and increased (p<0.01) membrane fluidity (assessed with Merocyanine 540). These findings indicate that non-functional spermatozoa in the semen samples before freezing negatively influence the freezability of functional spermatozoa