Non-equilibrium view of the amorphous solidification of liquids with competing interactions.

The interplay between short-range attractions and long-range repulsions (SALR) characterizes the so-called liquids with competing interactions, which are known to exhibit a variety of equilibrium and non-equilibrium phases. The theoretical description of the phenomenology associated with glassy or gel states in these systems has to take into account both the presence of thermodynamic instabilities (such as those defining the spinodal line and the so called λ line) and the limited capability to describe genuine non-equilibrium processes from first principles. Here, we report the first application of the non-equilibrium self-consistent generalized Langevin equation theory to the description of the dynamical arrest processes that occur in SALR systems after being instantaneously quenched into a state point in the regions of thermodynamic instability. The physical scenario predicted by this theory reveals an amazing interplay between the thermodynamically driven instabilities, favoring equilibrium macro- and micro-phase separation, and the kinetic arrest mechanisms, favoring non-equilibrium amorphous solidification of the liquid into an unexpected variety of glass and gel states.

"Inner clocks" of glass-forming liquids.

Providing a physically sound explanation of aging phenomena in non-equilibrium amorphous materials is a challenging problem in modern statistical thermodynamics. The slow evolution of physical properties after quenches of control parameters is empirically well interpreted via the concept of material time (or internal clock) based on the Tool-Narayanaswamy-Moynihan model. Yet, the fundamental reasons of its striking success remain unclear. We propose a microscopic rationale behind the material time on the basis of the linear laws of irreversible thermodynamics and its extension that treats the corresponding kinetic coefficients as state functions of a slowly evolving material state. Our interpretation is based on the recognition that the same mathematical structure governs both the Tool model and the recently developed non-equilibrium extension of the self-consistent generalized Langevin equation theory, guided by the universal principles of Onsager's theory of irreversible processes. This identification opens the way for a generalization of the material-time concept to aging systems where several relaxation modes with very different equilibration processes must be considered, and partially frozen glasses manifest the appearance of partial ergodicity breaking and, hence, materials with multiple very distinct inner clocks.

Non-equilibrium relaxation and aging in the dynamics of a dipolar fluid quenched towards the glass transition.

The recently developed non-equilibrium self-consistent generalized Langevin equation theory of the dynamics of liquids of non-spherically interacting particles [2016J. Phys. Chem. B1207975] is applied to the description of the irreversible relaxation of a thermally and mechanically quenched dipolar fluid. Specifically, we consider a dipolar hard-sphere liquid quenched (attw= 0) from full equilibrium conditions towards different ergodic-non-ergodic transitions. Qualitatively different scenarios are predicted by the theory for the time evolution of the system after the quench (tw> 0), that depend on both the kind of transition approached and the specific features of the protocol of preparation. Each of these scenarios is characterized by the kinetics displayed by a set of structural correlations, and also by the development of two characteristic times describing the relaxation of the translational and rotational dynamics, allowing us to highlight the crossover from equilibration to aging in the system and leading to the prediction of different underlying mechanisms and relaxation laws for the dynamics at each of the glass transitions explored.

Modeling the intracellular dynamics of the dengue viral infection and the innate immune response.

The interplay between the dengue virus and the innate immune response is not fully understood. Here, we use deterministic and stochastic approaches to investigate the dynamics of the interaction between the interferon-mediated innate immune response and the dengue virus. We aim to develop a quantitative representation of these complex interactions and predict their system-level dynamics. Our simulation results predict bimodal and bistable dynamics that represent viral clearance and virus-producing states. Under normal conditions, we determined that the viral infection outcome is modulated by the innate immune response and the positive-strand viral RNA concentration. Additionally, we tested system perturbations by external stimulation, such as the direct induction of the innate immune response by interferon, and a therapeutic intervention consisting of the direct application of mRNA encoding for several interferon-stimulated genes. Our simulation results suggest optimal regimes for the studied intervention approaches.

Efecto de un entrenamiento corto en habilidades de comunicación con el método CICAA (conectar, identificar, comprender, acordar y ayudar), en médicos residentes de una universidad peruana / Effect of a short training in communication abilities with the CICAA method in an university in Lima, Peru

Objetivo: Evaluar la eficacia de un entrenamiento corto en habilidades de comunicación con el método CICAA (conectar, identificar, comprender, acordar y ayudar) en una universidad de Lima-Perú. Material y métodos: Estudio de intervención antes y después, donde cada médico residente fue su propio control. Participantes: 25 médicos residentes del primer año académico de los programas de especialización en medicina familiar, medicina interna y pediatría de la Universidad Peruana Cayetano Heredia (UPCH). Intervención: Entrenamiento en entrevista clínica basado en el método CICAA. El método CICAA incluye cuatro tareas agrupadas en tres dominios: Conectar (dominio 1), Identificar y comprender (dominio 2), Acordar y Ayudar (dominio 3). Se realizó un entrenamiento de 26 horas de duración, el cual consistió en clases teóricas, talleres, role-play de escenarios diseñados por los docentes y alumnos. Se diseñó una evaluación clínica objetiva estructurada (ECOE) con la participación de dos pacientes estandarizados. Se utilizó el score CICAA para calificar la entrevista clínica tanto antes como una semana después del entrenamiento. Resultados: La media de la calificación total antes del entrenamiento fue de 29,84 ± 1,44; 8,72 ± 0,33, 12,8 ± 1,02 y 8,32 ± 0,67 para los dominios 1, 2 y 3, respectivamente. Después del entrenamiento, la calificación total fue de 40,84 ± 1,32; 11 ± 0,26, 16,04 ± 1,01 y 13,44 ± 0,51, para los dominios 1,2 y 3, respectivamente. Conclusiones: La implementación de un entrenamiento corto sobre habilidades de comunicación basado en teoría y juego de roles tiene un impacto positivo en una evaluación temprana.

Objective: To evaluate the efficacy of a short training in communication abilities with the CICAA method in a university in Lina, Peru. Methods: A before-after study design was undertaken where each resident was a control. Participants: 25 first year residents of family medicine, internal medicine and pediatrics of Universidad Peruana Cayetano Heredia. Intervention: training in the CICAA method which includes four areas grouped in three domains; connecting (domain 1), identifying and learning (domain 2); and remembering and helping (domain 3). A short training of 26 hours was conducted including lectures, workshops, and play-role activities for students and teachers. A structure objective assessment with the participation of two standardized patients was carried-out. CICAA score was used to evaluate the clinical interview one week before and after the training. Results: The mean value of the overall evaluation was 29.84 ± 1.44; 8.72 ± 0.33, 12.8 ± 1.02 and 8.32 ± 0.67 for domains 1-3, respectively. Values after the training were 40.84 ± 1.32; 11 ± 0.26, 16.04 ± 1.01 and 13.44 ± 0.51, for domains 1-3, respectively. Conclusion: The implementation of a short training in communication abilities based on lectures and play-role has a positive impact on an early evaluation.

Glassy dynamics in asymmetric binary mixtures of hard spheres.

We perform a systematic and detailed study of the glass transition in highly asymmetric binary mixtures of colloidal hard spheres, combining differential dynamic microscopy experiments, event-driven molecular dynamics simulations, and theoretical calculations, exploring the whole state diagram and determining the self-dynamics and collective dynamics of both species. Two distinct glassy states involving different dynamical arrest transitions are consistently described, namely, a double glass with the simultaneous arrest of the self-dynamics and collective dynamics of both species, and a single glass of large particles in which the self-dynamics of the small species remains ergodic. In the single-glass scenario, spatial modulations in the collective dynamics of both species occur due to the structure of the large spheres, a feature not observed in the double-glass domain. The theoretical results, obtained within the self-consistent generalized Langevin equation formalism, are in agreement with both simulations and experimental data, thus providing a stringent validation of this theoretical framework in the description of dynamical arrest in highly asymmetric mixtures. Our findings are summarized in a state diagram that classifies the various amorphous states of highly asymmetric mixtures by their dynamical arrest mechanisms.

Explained and unexplained tissue loss in corals from the Tropical Eastern Pacific.

Coral reefs rival rainforest in biodiversity, but are declining in part because of disease. Tissue loss lesions, a manifestation of disease, are present in dominant Pocillopora along the Pacific coast of Mexico. We characterized tissue loss in 7 species of Pocillopora from 9 locations (44 sites) spanning southern to northern Mexico. Corals were identified to species, and tissue loss lesions were photographed and classified as those explainable by predation and those that were unexplained. A focal predation study was done concurrently at 3 locations to confirm origin of explained lesions. Of 1054 cases of tissue loss in 7 species of corals, 84% were associated with predation (fish, snails, or seastar) and the remainder were unexplained. Types of tissue loss were not related to coral density; however there was significant geographic heterogeneity in type of lesion; one site in particular (Cabo Pulmo) had the highest prevalence of predator-induced tissue loss (mainly pufferfish predation). Crown-of-thorns starfish, pufferfish, and snails were the most common predators and preferred P. verrucosa, P. meandrina, and P. capitata, respectively. Of the 9 locations, 4 had unexplained tissue loss with prevalence ranging from 1 to 3% with no species predilection. Unexplained tissue loss was similar to white syndrome (WS) in morphology, indicating additional study is necessary to clarify the cause(s) of the lesions and the potential impacts to dominant corals along the Pacific coast of Mexico.

Gross and microscopic pathology of lesions in Pocillopora spp. from the subtropical eastern Pacific.

Coral reefs are threatened by a variety of factors including diseases that have caused significant damage in some regions such as in the Caribbean. At present, no data are available on coral diseases in the Mexican Pacific where Pocillopora spp. is a dominant component of coral communities. Here, we describe gross and microscopic morphology of lesions found in pocilloporids at four sites in the Mexican Pacific. Corals were identified and their lesions photographed and quantified in the field. Tissue samples were collected from healthy and affected colonies for histopathology. We recorded seven species of pocilloporids at the study sites with Isla Isabel being the location with the highest coral diversity (H'=1.27). Lesions were present in 42% of the colonies and included discoloration (32%), predation-induced tissue loss (30%), unexplained tissue loss (3%) and overgrowth by sponges or algae (35%). The most affected species, P. damicornis (50%), was also one of the most common in the region. No species was more prone to a particular lesion, but there was a significant association between location and the presence of lesions. Northern Islas Marietas (61%) and Isla Isabel (41%) had the highest prevalence of lesions, followed by Manzanillo (37%) and Bahías de Huatulco (23%). Histological changes included atrophy of the surface body wall with depletion of zooxanthellae (91%) in corals with discoloration (bleaching). Ablation of tissue from mesoglea (18%) was also observed. Colonies with unexplained tissue loss showed atrophy and thinning of the epidermis (89%), characterized by cuboidal instead of pseudocolumnar cells normally found in healthy pseudocolumnar ciliated epithelium. Bacterial aggregates between the mesoglea and gastrodermis (11%) were very conspicuous in healthy and diseased corals. Lesions produced by fish bites and gastropods were associated with tissue atrophy (40%) and, in some cases, algal overgrowth near the lesion (20%). No infectious agents associated with cell pathology were detected microscopically. Bleaching and overgrowth by algae and sponges, as well as unexplained tissue loss, are common in Pocillopora. These lesions and anatomical changes warrant further study since their incidence is potentially indicative of reef degradation.

Testing the genetic predictions of a biogeographical model in a dominant endemic Eastern Pacific coral (Porites panamensis) using a genetic seascape approach.

The coral fauna of the Eastern Tropical Pacific (ETP) is depauperate and peripheral; hence, it has drawn attention to the factors allowing its survival. Here, we use a genetic seascape approach and ecological niche modeling to unravel the environmental factors correlating with the genetic variation of Porites panamensis, a hermatypic coral endemic to the ETP. Specifically, we test if levels of diversity and connectivity are higher among abundant than among depauperate populations, as expected by a geographically relaxed version of the Abundant Center Hypothesis (rel-ACH). Unlike the original ACH, referring to a geographical center of distribution of maximal abundance, the rel-ACH refers only to a center of maximum abundance, irrespective of its geographic position. The patterns of relative abundance of P. panamensis in the Mexican Pacific revealed that northern populations from Baja California represent its center of abundance; and southern depauperate populations along the continental margin are peripheral relative to it. Genetic patterns of diversity and structure of nuclear DNA sequences (ribosomal DNA and a single copy open reading frame) and five alloenzymatic loci partially agreed with rel-ACH predictions. We found higher diversity levels in peninsular populations and significant differentiation between peninsular and continental colonies. In addition, continental populations showed higher levels of differentiation and lower connectivity than peninsular populations in the absence of isolation by distance in each region. Some discrepancies with model expectations may relate to the influence of significant habitat discontinuities in the face of limited dispersal potential. Environmental data analyses and niche modeling allowed us to identify temperature, water clarity, and substrate availability as the main factors correlating with patterns of abundance, genetic diversity, and structure, which may hold the key to the survival of P. panamensis in the face of widespread environmental degradation.

[Community structure of zooxanthellate corals (Anthozoa: Scleractinia) in Carrizales coral reef, Pacific coast, Mexico]. / Estructura comunitaria de corales zooxantelados (Anthozoa: Scleractinia) en el arrecife coralino de Carrizales, Pacifico Mexicano.

Coral reefs in the Mexican Pacific and notably those of the continental coastline of Colima state are still poorly studied. Fortunately, recent efforts have been carried out by researchers from different Mexican institutions to fill up these information gaps. The aim of this study was to determine the ecological structure of the rich and undisturbed coral building communities of Carrizales by using the point transect interception method (25m-long). For this, three survey expeditions were conducted between June and October 2005 and September 2006; and for comparison purposes, the reef was subdivided according to its position in the bay, and depth (0 to 5 m, and 6 to 10 m). Thirteen coral species were observed in the area, with Pocillopora verrucosa as the most abundant, contributing up to 32.8% of total cover, followed by Porites panamensis and Pocillopora capitata with 11% and 7%, respectively. Other species, Pocillopora damicornis, Pavona gigantea, Pocillopora eydouxi and Pocillopora inflata accounted for 1.5% to 2% of coral cover whereas the remaining five species had cover of less than 1%. Seven of the observed species represented new records for Colima state coastline: Pocillopora eydouxi, P inflata, P meandrina, Pavona duerdeni, P varians, Psammocora stellata and P contigua. This last species is a relevant record, because it has never been observed before in the Eastern Pacific. Although there was no significant difference (ANOVA, p = 0.478) neither in the abundance between the sides of the bay, nor between the depths considered, and the shallow zone observed the higher coral cover. Live coral cover was up to 61%, one of the highest ever reported for the Mexican Pacific, including the Gulf of California. The observed values of diversity (H' = 0.44 +/- 0.02), uniformity (J' = 0.76 +/- 0.02), and taxonomic distinctness index (delta* = 45.87 +/- 3.16), showed that currently this is the most important coral reef of Colima coastline. Currently, this region does not show any disturbance effects, but the increasing economic development of Manzanillo, as one of the main commercial ports of Mexico, its proximity to the reef, and the burgeoning number of tourists, may have some ecosystem impacts, for which management and conservation plans for Colima coastline are highly recommended.

Estructura comunitaria de corales zooxantelados (Anthozoa: Scleractinia) en el arrecife coralino de Carrizales, Pacífico Mexicano / Community structure of zooxanthellate corals (Anthozoa: Scleractinia) in Carrizales coral reef, Pacific coast, Mexico

Coral reefs in the Mexican Pacific and notably those of the continental coastline of Colima state are still poorly studied. Fortunately, recent efforts have been carried out by researchers from different Mexican institutions to fill up these information gaps. The aim of this study was to determine the ecological structure of the rich and undisturbed coral building communities of Carrizales by using the point transect interception method (25m-long). For this, three survey expeditions were conducted between June and October 2005 and September 2006; and for comparison purposes, the reef was subdivided according to its position in the bay, and depth (0 to 5m, and 6 to 10m). Thirteen coral species were observed in the area, with Pocillopora verrucosa as the most abundant, contributing up to 32.8% of total cover, followed by Porites panamensis and Pocillopora capitata with 11% and 7%, respectively. Other species, Pocillopora damicornis, Pavona gigantea, Pocillopora eydouxi and Pocillopora inflata accounted for 1.5% to 2% of coral cover whereas the remaining five species had cover of less than 1%. Seven of the observed species represented new records for Colima state coast- line: Pocillopora eydouxi, P. inflata, P. meandrina, Pavona duerdeni, P. varians, Psammocora stellata and P. contigua. This last species is a relevant record, because it has never been observed before in the Eastern Pacific. Although there was no significant difference (ANOVA, p=0.478) neither in the abundance between the sides of the bay, nor between the depths considered, and the shallow zone observed the higher coral cover. Live coral cover was up to 61%, one of the highest ever reported for the Mexican Pacific, including the Gulf of California. The observed values of diversity (H´=0.44±0.02), uniformity (J´=0.76±0.02), and taxonomic distinctness index (Δ*=45.87±3.16), showed that currently this is the most important coral reef of Colima coastline. Currently, this region does not show any disturbance effects, but the increasing economic development of Manzanillo, as one of the main commercial ports of Mexico, its proximity to the reef, and the burgeoning number of tourists, may have some ecosystem impacts, for which management and conservation plans for Colima coastline are highly recommended.

El conocimiento ecológico de corales arrecifales en el Pacífico mexicano es escaso, por lo que el objetivo de este trabajo fue determinar la estructura de la comunidad de corales hermatípicos en el arrecife de Carrizales, Colima, mediante el uso de transectos y buceo autónomo (junio y octubre 2005, septiembre 2006). De las 13 especies de corales encontradas, Pocillopora verrucosa fue la más abundante y siete representan nuevos registros, sobresaliendo Psammocora contigua, primer registro para el Pacífico Oriental. No hubo diferencias significativas de abundancia entre profundidades, pero la zona somera presenta una mayor cobertura. Este sitio presenta una de las riquezas y cobertura de coral más alta (61%) en el Pacífico Mexicano y valores de diversidad (H´=0.44±0.02), uniformidad (J´=0.76±0.02), y de diferenciación taxonómica (Δ*=45.87±3.16) relativamente altos. Actualmente la región no presenta grandes perturbaciones pero el creciente desarrollo económico de Manzanillo, uno de los principales puertos comerciales del país, además del creciente número de turistas, podrían afectar al arrecife, por lo que se sugiere implementar medidas de protección con el fin de mantener al arrecife más importante del litoral de Colima.

What is the core oscillator in the speract-activated pathway of the Strongylocentrotus purpuratus sperm flagellum?

Sperm chemotaxis has an important role in fertilization. Most of our knowledge regarding this phenomenon comes from studies in organisms whose fertilization occurs externally, like sea urchins. Sea urchin spermatozoa respond to sperm-activating peptides, which diffuse from the egg jelly coat and interact with their receptor in the flagellum, triggering several physiological responses: changes in membrane potential, intracellular pH, cyclic nucleotide levels, and intracellular Ca2+ concentration ([Ca2+]). In particular, flagellar [Ca2+] has been shown to oscillate. These [Ca2+] oscillations are correlated with changes in the flagellar shape and so with the regulation of the sperm swimming paths. In this study, we demonstrate, from a mathematical modeling perspective, that the reported speract-activated signaling pathway in Strongylocentrotus purpuratus (speract being a sperm-activating peptide specific to this species) has the necessary elements to replicate the reported [Ca2+] oscillations. We further investigate which elements of this signaling pathway constitute the core oscillator.

Comportamiento sexual y uso del preservativo en adolescentes y jóvenes de un área de salud / Sexual relation and the use of condom in adolescents and young people from a health area

Las infecciones de transmisión sexual en general, y de manera especial, el VIH/SIDA en los adolescentes y jóvenes constituyen un serio problema de salud y el riesgo de padecerlas está muy relacionado con el comportamiento sexual y las formas de protegerse, entre otros factores. Esto motivó el estudio para identificar los comportamientos sexuales y el uso del preservativo como medio de protección hacia estas enfermedades, como etapa previa a un estudio de intervención. La muestra la integraron 100 adolescentes y jóvenes de un área de salud del municipio Centro Habana. Para dar salida a los objetivos se confeccionó un cuestionario autoaplicado. Los principales resultados fueron: el 61 por ciento de los encuestados tenía vida sexual activa, el inicio de las relaciones ocurrió en un 44 por ciento en las edades comprendidas entre los 15 y los 19 años, y en el 55 por ciento, antes de los 20. El preservativo no se usó nunca en el 30 por ciento de las encuestadas y ocasionalmente en un 49 por ciento. Las principales causas argumentadas para no usarlo fueron expresar que resultaba incómodo y que no le gustaba a su pareja

Virus del papiloma humano: visión actual en biomedicina / Human papillomavirus: a current view in biomedicine

Los papilomavirus humanos (VPH) son virus epiteliotrópicos de doble cadena de ADN que producen lesiones verrugosas en piel y mucosas. Actualmente se conocen más de 100 tipos, algunos de los cuales tienen potencial oncogénico variable, dependiendo de la capacidad de transformación e integración en la célula hospedadora y están fuertemente asociados con cáncer cervical, así como otros tipos de cáncer. Aún cuando los métodos tradicionales, como la técnica de Papanicolaou, siguen siendo una herramienta valiosa para el tamizaje de las lesiones producidas por el VPH, en las últimas décadas se han usado técnicas moleculares como la reacción en cadena de polimerasa, hibridación in situ, captura de híbridos, entre otras, las cuales son más efectivas en cuanto a la detección de la infección. El objetivo de esta revisión es proporcionar información amplia y actualizada sobre el VPH que permitirá el mejor entendimiento del virus, su comportamiento patológico, epidemiológico, nuevos enfoques de diagnóstico y recientes avances en el área preventiva

Does damming of the Colorado River affect the nursery area of blue shrimp Litopenaeus stylirostris (Decapoda: Penaeidae) in the Upper Gulf of California?

After damming the Colorado River the freshwater flow was reduced to 1 of its virgin flow to the Upper Gulf of California (UGC). The ecological effects need to be properly documented. The UGC is the nursery area for Litopenaeus stylirostris, the most profitable fishery in the zone. In order to know the relative abundance of L. stylirostris postlarval stage we conducted a sampled survey every 14 days in 1993, 1994 and 1997, plus an intensive sampling during a complete tide cycle in July 1995 and 1996. We did 10 min trawls each hour during the flood tide. Relative abundance of postlarvae was higher (p < 0.05) in those years when freshwater flow reached the UGC.

Tratamiento endovascular de aneurisma intracraneal: reporte de un caso / Processing to endovascular of intracraneal aneurism: report of a case

Expone que la causa más común de hemorragia subaracnoidea en adultos es la ruptura de un aneurisma intracraneal, el cual es una dilatación focal anormal de una arteria, pudiendo clasificarse por su morfología en sacular y fusiforme y por su etiología en congénitos, adquiridos, arterioescleróticos, micóticos y disecantes. Las alternativas terapéuticas son: el clipaje quirúrgico y la embolización endovascular. En el siguiente trabajo, se presenta el caso de un paciente de sexo masculino de 38 años de edad, con antecedentes de hemorragia subaracnoidea, por aneurisma de la arteria cerebral media izquierda, sometida a embolización endovascular con coils GDC con resultado exitoso.

Incidencia y prevalencia de infección de vías urinarias Hospital Provincial de Cotopaxi / Incidence and prevalence of infection of urinary channels Provincial Hospital of Cotopaxi

Estudia la incidencia de infección de vías urinarias, en pacientes atendidos en el Hospital Provincial de Cotopaxi. En un país como el nuestro es de mucha utilidad el conocer la frecuencia con que se presenta la infección del tracto urinario, puesto que a la postre puede constituirse en un problema de salud de la población. Con esto se ha estudiado una población específica recopilada de las historias clínicas de 1987 a 1991. Se analizan variables como: edad, sexo, situación socioeconómica, lugar de procedencia, el diagnóstico hecho con laboratorio o sin él, y las principales manifestaciones clínicas; además de prevalencia por sexo y grupos etáreos. Observaciones que existen mayor prevalencia de infección de vías urinarias en el sexo femenino y la edad comprendida que coincide con la época fértil y vida sexual activa en la mujer...

Estudio sobre egresos hospitalarios de diabetes mellitus en el Hospital Provincial de Cotopaxi / Study on hospitable debits of diabetes mellitus in the Provincial Hospital of Cotopaxi

Presenta un estudio retrospectivo cualicuantitativo de 46 pacientes cuyo diagnóstico de egreso fue diabetes mellitus entre ene. 1987 y mar. 1992, utilizan la información tomada de las fichas médicas que reposan en el Departamento de Estadística del Hospital Provincial de Cotopaxi, observándose que en un 0.85xciento de la población total de pacientes de dicho hospital tienen diabetes mellitus, que la de tipo II es más frecuente que la de tipo I en una relación de 2.83 a 1. El 100xciento de diabetes tipo I son insulinodependientes y que afecta a la población jóven; los pacientes de tipo II se controlan en su mayoría con antidiabéticos orales y dieta...