228 research outputs found
Developing a strain improvement system for the entomopathogenic fungus Beauveria basssiana: a way to get better biocontrol agents?
Biocontrol agents (BCAs) based on entomopathogenic fungi (EPF) are playing an increasing role in Integrated Pest Management programmes. At present, the commercially available EPF consist of wild type strains isolated from nature, however, there is potential to breed more effective strains by recombining wild types with complementary characteristics. EPF Beauveria bassiana represents one of the most important organisms used to kill arthropod pests, as they occurred naturally in the environment, do not leave residual activity, are safer for human manipulation and they usually show a high virulence. The aim of this research was to develop a system to improve strains of the entomopathogenic fungus B. bassiana through genetic recombination. A group of 50 Beauveria strains were genotyped using multi-locus sequencing and mating gene analysis, and then phenotyped with respect to their virulence against Diamondback moth (DBM), thermal biology, tolerance of UV light, and conidial production. A phylogenetic analysis identified two different Beauveria species within the fungal collection: B. bassiana (78%) and Beauveria pseudobassiana (16%). Seven strains from different places of origin were selected with phenotypes such as tolerance to UV-B radiance, thermotolerance, virulence and potentially compatible mating types for parasexual recombination studies. Spontaneously generated nitrate non-utilizing (nit) mutants were produced from these strains using a potassium chlorate-amended selective medium and 35 vegetative compatibility groups were determined within the 50 isolates of Beauveria spp. Recombination by hyphal fusion and protoplast fusion proved to be feasible and was observed in two out of three crosses. Only one cross (X2) showed higher radial growth than the parental strains between 20 and 30 °C. Nine fungal strains were selected to investigate the potential for inducing sexual recombination by pairing complementary mating types on three different media that have probed work well in other fungal species (oatmeal agar, malt extract agar, and Czapek Dox agar +/- biotin). After six months, both in vitro and in vivo assays led to the generation of structures resembling synnemata, however no fruiting bodies nor other clear sexual structures were observed. No relationship was found between the geographical origin of the strains and their tolerance to temperature or UV-B light, suggesting that micro-environmental conditions can play a more important role in the development of determined traits of organisms sourced from specific ecosystems than the latitude or altitude of sampling locations. This study provides a significant amount of information describing several methodologies for parasexual and sexual recombination of this fungus, expanding the current knowledge of this valuable EPF
Editorial: Physiology and pathology of neuroglia
Neuroglia is the largest population of cells in the brain and participates in formation, maintenance, and modulation of synaptic circuits. This heterogenous group includes macroglia (astroglia and oligodendroglia) and microglia. Neurons and neuroglia form assemblies that potentiate the cognitive capability of the brain. In this topic, nine articles highlight structural and functional roles of neuroglia in brain physiology, which is fundamental to better understand the biology of neurodevelopmental and neurodegenerative diseases.
Our understanding of brain connectivity evolves rapidly and the cytoarchitecture of underexplored brain regions such as the cerebellum need to be revisited (De Zeeuw et al., 2021). Hence, Gómez-González et al. reviewed the organization of a peculiar cerebellar glial niche located at the subventricular zone of the fourth ventricle. In addition to neurons and ependymal cells, this region is rich in microglia as well as macroglia including astrocytes, Bergmann glia, and oligodendrocyte lineage cells. Further transcriptional and functional heterogeneity within these glial populations is discussed. Despite scarce to non-proliferative activity, this region shares similarity with adult neurogenic niches throughout the brain and various stimulating questions remain to be explored. Furthermore, glial organization is adapted to this highly vascularized niche and contribute to the glioneurovascular unit, a structural and functional element where glial cells respond to stimulation by coupling to increased sensory activity through development (Biesecker et al., 2016; Koehler, 2021). In a perspective contributed by Konecny et al., they hypothesize that augmented neuronal activity is associated with angiogenic factor production and creates an environment of intermittent hypoxia, promoting the expression of hypoxia-inducible transcription factors (HIFs) by the glioneurovascular unit. However, mechanisms triggering glioneurovascular coupling during early sensory neurodevelopment are unknown; therefore, further research using non-invasive approaches is proposed.
Neuron-glia coupling is physiologically tied to volume regulation. Ionic gradients permit neurons to communicate electrically, and glial cells help them to regulate volume. Astrocytes express a variety of cotransport systems and ion channels to maintain brain homeostasis through mobilization of osmolytes (Walch and Fiacco, 2022). Ochoa-de la Paz and Gulias-Cañizo identify glial cells as master regulators of the tripartite synapse volume, a property that gives them an important role in maintaining homeostasis. Dysfunction of volume regulation leads to pathology in conditions such as edema, uremia, and diabetes, in which solute imbalances occur.
Neuron-glia communication is mediated by neurotransmitters including glutamate, the main excitatory neurotransmitter of the brain. This signaling occurs through ionotropic and metabotropic receptors expressed by neurons and glial cells. Particularly, astrocytes modulate neuronal activity through release of gliotransmitters like glutamate and D-serine (Reyes-Haro et al., 2010). Additionally, astrocytes express glutamate transporters to regulate the glutamatergic tone at the synaptic cleft and supply glutamine to neurons that convert it into glutamate or GABA to refill synaptic vesicles (Martínez-Lozada and Ortega, 2023). Dysfunction of the glutamate-glutamine shuttle results in excitotoxicity that has been linked to Alzheimer\u27s and Huntington\u27s diseases. Thus, Cuellar-Santoyo et al. summarize the astrocyte\u27s contribution to glutamatergic neurotransmission in physiological and pathological conditions.
Astrocytes also respond to neuronal activity with calcium transients, a signaling mechanism that seems involved in pain and nociception (Prokhorenko and Smyth, 2023). Here, Higinio-Rodríguez et al. present an experimentally supported perspective in which coherent activity of astrocytes in pain-related brain areas plays critical roles in binding sensory, affective, and cognitive information, on a slow time scale. As astrocytes respond to noxious stimuli via calcium modulation likely independent of neuronal activation, this could represent the mechanism by which pain is created from nociception with the participation of astrocytes.
Glial cell responses in pathology involve inflammasomes, multi-protein intracellular signaling complexes which orchestrate inflammatory responses to a diverse range of pathogens and host-derived signals (Jewell et al., 2022). In their review article, Mata-Martínez et al., discuss aspects of the inflammatory process, focusing on accumulating evidence of multiprotein complexes that sense and respond in the context of inflammation. The authors argue that acute and chronic inflammation will engage a coordinated molecular response in various organs, involving glial cells in the brain. Interestingly, Down syndrome (DS) and Alzheimer\u27s disease (AD) are characterized by chronic neuroinflammation, peripheral inflammation, astrogliosis, imbalanced excitatory/inhibitory neuronal function, and cognitive deficits in both humans and mouse models (Ahmed et al., 2022). Little is known about the causes of these pathologies, but patients with DS are suspected to be predisposed to developing AD late in life. García and Flores-Aguilar summarize data about glial cells in the context of DS-AD and inflammation.
Links for inflammation and glial cells could also exist in anorexia; food intake is reduced during acute and chronic inflammatory states in human and research models (Gautron and Layé, 2010). Reyes-Haro reviews features of physiological anorexia in research models in comparison with human pathological anorexia, emphasizing valid precautions when extrapolating results. Moreover, he discusses studies in murine models of anorexia in which glial cells putatively play central roles in classical hypothalamic mechanisms, as well as in systemic machineries including the prefrontal cortex. Specifically, the pro-inflammatory environment associated with microglia reactivity, the impact of astrocyte manipulation on food intake associated with purinergic gliotransmission, and the roles of Oligodendrocyte Precursor Cells (OPCs) mediating the anorexigenic action of leptin in mice, are presented.
Another pathology associated with glial cell dysfunction is alcohol exposure during pregnancy. Fetal Alcohol Syndrome (FAS) is a public health problem with a prevalence of 2–5% in the USA. FAS disturbs the structure and function of the brain, but the underlying mechanisms remain elusive (Holloway et al., 2023). Zheng et al., observed loss of the tubulin-binding cofactor B resulting in disorganized microtubules and shortening of astrocytic processes in a model of chronic alcohol exposure. Developmental pathological implications to consider include abnormal migration of neuronal precursors through aberrant radial glial processes and defective synaptic coverage by astrocytes.
Overall, articles in this topic cover diverse aspects of research on glial cells and serve as introductory information to several subfields of glial biology. Ideas presented encourage others to design studies to clarify the roles of physiological and pathological factors with potential use in therapeutic applications and engineering
La atención médica y su influencia en la satisfacción del paciente: una revisión de la literatura científica
RESUMEN
El presente estudio se enmarca en el sector de servicios de salud en su primer nivel de atención, dada la importancia que representa para los centros de salud públicos evaluar aspectos como la atención médica y la calidad de los servicios de salud, ya que les permitirá identificar áreas de oportunidad. Cuyo objetivo es analizar los estudios teóricos sobre cómo ha influenciado la atención médica en la satisfacción de los pacientes en el siglo XXI. La consulta de la información se efectuó utilizando bases de datos como el EBSCO host Research Databases, Scielo, DOAJ y Google Académico. Para los resultados de la presente investigación teórica se procedió con una metodología basada en tres pasos básicos y fundamentales que son Búsqueda, Selección y Análisis de Datos obteniéndose 30 documentos, siendo la revista Scielo la que proporcionó la mayor cantidad con 18 y Google Académico con siete. Finalmente, con tres aporto DOAJ y EBSCO con dos. Podemos concluir que existe información necesaria que sustentará la investigación a desarrollar sobre la atención médica y su influencia en la satisfacción del paciente del CAP Metropolitano III Trujillo.
PALABRAS CLAVES: atención médica, calidad, satisfacción del cliente
Communication: Virial coefficients and demixing in highly asymetric binary additive hard-sphere mixtures
Publicado en: J. Chem. Phys. 138, 161104 (2013)
DOI: 10.1063/1.4803097Se revisa el problema de la disgregación de una mezcla binaria fluida con aditivos altamente asimétricos de esferas duras. Se presenta una comparación entre los resultados previos obtenidos usando expansiones de viriales truncados para tres relaciones de tamaño finito; con ellos se obtiene el mismo enfoque en el caso extremo en el que uno de los componentes consiste en partículas puntuales. Dado que este último sistema es conocido por no exhibir la segregación de líquido fluido, la similitud observada en el comportamiento de las constantes críticas surgidas en la serie truncada en todos los casos, si bien no es concluyente, podrá emitir con serias dudas como la existencia real de un separador de mezclas en la transición de líquido a fluido es de tamaños dispares y de aditivos binarios en mezclas de esferas duras.The problem of demixing in a binary fluid mixture of highly asymmetric additive hard spheres is revisited. A comparison is presented between the results derived previously using truncated virial expansions for three finite size ratios with those that one obtains with the same approach in the extreme case in which one of the components consists of point particles. Since this latter system is known not to exhibit fluid-fluid segregation, the similarity observed for the behavior of the critical constants arising in the truncated series in all instances, while not being conclusive, may cast serious doubts as to the actual existence of a demixing fluid-fluid transition in disparate-sized binary additive hard-sphere mixtures.Andrés Santos Reyes ha sido financiado por el Gobierno de España a través del proyecto FIS2010-16587 (I+D+i) y por la Junta de Extremadura (España), ayuda GR10158 parcialmente financiada con Fondos FEDE
Actitudes hacia el aprendizaje cooperativo y enfoque histórico
Education of personality through teaching-learning processes (in Spanish, PEA) based on the cultural- historical psychology, stimulate the zone of proximal development (ZPD) and promote human development through particular forms of organization of individuals and knowledge. The development of feelings, attitudes, values, thoughts, imagination, attention among others, is its essential concern. That is why this study aims to demonstrate that teaching with a cultural-historical psychology develops a predisposition and attitudes towards teamwork. This study aims to demonstrate that teaching with a cultural- historical psychology, develops attitudes favourable to teamwork. The research is quasi-experimental with a pretest-posttest design and includes a control group. Students from schools with whom teachers worked in training in pre-professional practice were selected for intervention.835 students participated in the research, from which 430 make up the experimental group consisting of students of Basic Superior in an average age of 13.4 (± 0.95) years and Senior High School of 16.4 (± 1.6) years.The control group includes 405 students of Basic education and Senior High school, whose ages are similar to the experimental group. In the PEA of the experimental group, a class design was used which, in organizational forms, emphasizes cooperative work techniques. The Predisposition and Attitudes towards Teamwork Questionnaire (in Spanish, CACTE) was applied. After the intervention, the experimental group had a significant increase (p smaller than 0.001) with respect to the control group and its effect size was medium (r = 0.27), a situation that makes it possible to affirm that the application of teamwork with cooperative learning techniques, contributes to the development of sociability, raises self-esteem, and guarantees significant learning for the person, reduces individualism and competence.La educación de la personalidad mediante procesos de enseñanza aprendizaje (PEA) sustentados en el enfoque histórico cultural, estimulan la zona de desarrollo próximo (ZDP) y promueven el desarrollo humano mediante particulares formas de organización de los individuos y del conocimiento. El desarrollo de sentimientos, actitudes, valores, pensamientos, imaginación, atención, entre otros, es su preocupación esencial. Este estudio tiene como objetivo demostrar que la enseñanza con el enfoque histórico cultural desarrolla actitudes favorables al trabajo en equipo. La investigación es de corte cuasi-experimental con un diseño pretest-postest con grupo control.Se seleccionaron para la intervención a estudiantes de los colegios con quienes trabajaron los docentes en formación en la práctica pre-profesional. Intervinieron en la investigación 835 estudiantes, 430 conforman el grupo experimental integrado por estudiantes de Básica Superior en una media de edad de 13,4 (±0,95) años y de Bachillerato de 16,4 (±1,6)años. El grupo control integran 405 estudiantes de Básica y Bachillerato, cuyas edades son similares al grupo experimental. En el PEA del grupo experimental se utilizó un diseño de clase que, en las formas organizativas pone énfasis en técnicas de trabajo cooperativo. Se aplicó el cuestionario de Predisposición y Actitudes ante el trabajo en equipo (CACTE). Tras la intervención, el grupo experimental tuvo un incremento significativo (p menor que 0,001) respecto al grupo control, su tamaño del efecto fue mediano (r=0,27), situación que permite afirmar que trabajar en equipo con técnicas de aprendizaje cooperativo desarrolla sociabilidad, eleva la autoestima y garantiza aprendizajes significativos para la persona, aminora el individualismo y la competencia
Crystallization of PNIPAM-hydrogel nanospheres inferred by static light scattering
In this paper we present a kinetic study on crystallization of a colloidal dispersion formed by thermosensitive Poly-N- Isopropylacrylamide (PNIPAM) nanospheres. The liquid-crystal transition is induced by decreasing the temperature of the dispersion and the crystallization process is monitored by measuring the evolution of the static structure factor of the dispersion by means of light scattering techniques. The measured static structure factor confirms the formation of a mesoscopic crystal array at the final equilibrium state, which is preceded by two stages: nucleation and crystal growth
Acoso sexual callejero y bienestar psicológico en mujeres jóvenes del distrito de Lince, Lima, 2021
Esta investigación tuvo como principal objetivo comprobar la relación entre acoso
sexual callejero y bienestar psicológico en mujeres jóvenes de Lince, Lima.
El presente estudio se desarrolló dentro del enfoque cuantitativo, de diseño
descriptivo-correlacional, no experimental y de corte transversal; con una muestra
conformada por 385 mujeres jóvenes del distrito de Lince, con edades de los 18 a
45 años.
Los instrumentos empleados fueron el cuestionario de acoso sexual en vía pública
de Persíngola y Zanotti y la escala de bienestar psicológico para adultos (BIEPSA),
los cuales permitieron comprobar que existe correlación inversa significativa a
nivel de p<.01, entre las variables con un valor de (Rho=-.200**).
Por lo tanto, se infiere que, a mayor acoso sexual callejero, menor será el bienestar
psicológico en las mujeres
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