Extra-embryonic tissue spreading directs early embryo morphogenesis in killifish

The spreading of mesenchymal-like cell layers is critical for embryo morphogenesis and tissue repair, yet we know little of this process in vivo. Here we take advantage of unique developmental features of the non-conventional annual killifish embryo to study the principles underlying tissue spreading in a simple cellular environment, devoid of patterning signals and major morphogenetic cell movements. Using in vivo experimentation and physical modelling we reveal that the extra-embryonic epithelial enveloping cell layer, thought mainly to provide protection to the embryo, directs cell migration and the spreading of embryonic tissue during early development. This function relies on the ability of embryonic cells to couple their autonomous random motility to non-autonomous signals arising from the expansion of the extra-embryonic epithelium, mediated by cell membrane adhesion and tension. Thus, we present a mechanism of extra-embryonic control of embryo morphogenesis that couples the mechanical properties of adjacent tissues in the early killifish embryo

A computational framework for testing hypotheses of the minimal mechanical requirements for cell aggregation using early annual killifish embryogenesis as a model

Introduction: Deciphering the biological and physical requirements for the outset of multicellularity is limited to few experimental models. The early embryonic development of annual killifish represents an almost unique opportunity to investigate de novo cellular aggregation in a vertebrate model. As an adaptation to seasonal drought, annual killifish employs a unique developmental pattern in which embryogenesis occurs only after undifferentiated embryonic cells have completed epiboly and dispersed in low density on the egg surface. Therefore, the first stage of embryogenesis requires the congregation of embryonic cells at one pole of the egg to form a single aggregate that later gives rise to the embryo proper. This unique process presents an opportunity to dissect the self-organizing principles involved in early organization of embryonic stem cells. Indeed, the physical and biological processes required to form the aggregate of embryonic cells are currently unknown.Methods: Here, we developed an in silico, agent-based biophysical model that allows testing how cell-specific and environmental properties could determine the aggregation dynamics of early Killifish embryogenesis. In a forward engineering approach, we then proceeded to test two hypotheses for cell aggregation (cell-autonomous and a simple taxis model) as a proof of concept of modeling feasibility. In a first approach (cell autonomous system), we considered how intrinsic biophysical properties of the cells such as motility, polarity, density, and the interplay between cell adhesion and contact inhibition of locomotion drive cell aggregation into self-organized clusters. Second, we included guidance of cell migration through a simple taxis mechanism to resemble the activity of an organizing center found in several developmental models.Results: Our numerical simulations showed that random migration combined with low cell-cell adhesion is sufficient to maintain cells in dispersion and that aggregation can indeed arise spontaneously under a limited set of conditions, but, without environmental guidance, the dynamics and resulting structures do not recapitulate in vivo observations.Discussion: Thus, an environmental guidance cue seems to be required for correct execution of early aggregation in early killifish development. However, the nature of this cue (e.g., chemical or mechanical) can only be determined experimentally. Our model provides a predictive tool that could be used to better characterize the process and, importantly, to design informed experimental strategies

Cuaderno de Trabajo Social N° 5

127 pag.Esta publicación contiene los siguientes artículos: Rol, Perfil y Espacio Profesional del Trabajo Social en el Ámbito Educativo ; Presentes y Ausentes: Los Podcast en la Formación Profesional del Trabajo Social ; Trabajo Social y Tecnologías de la Información y Comunicación: Desafíos para la Formación Profesional ; Una Revisión de los Factores que están Desafiando a la Educación Superior: Consideraciones para la Educación Formal del Trabajo Social ; “Yo Quería Conocer Más Mundo”: La Migración Infantil vista por las Niñas y los Niños Peruanos en Santiago de Chile ; “Del No me Acuerdo, al No Olvido”. Una Nueva Reinterpretación de la Victimización de las Jóvenes Institucionalizadas en Centros de Reforma en Andalucía ; La Historia del Poder y el Poder de la Historia. A propósito del Intento que Hace una Minoría Social por Borrar las Huellas e sus Horribles Crímenes Cometidos en el Pasado

An outbreak of hantavirus pulmonary syndrome, Chile, 1997

Fil: Toro, Jorge. Ministry of Health; Chile.Fil: Vega, Jeanette D. Pan American Health Organization; Chile.Fil: Khan, Ali S. Centers for Disease Control and Prevention; Estados Unidos.Fil: Mills, James N. Centers for Disease Control and Prevention; Estados Unidos.Fil: Padula, Paula. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Terry, William. Centers for Disease Control and Prevention; Estados Unidos.Fil: Yadón, Zaida. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Valderrama, Rosa. Aysen Region XI Health Service; Chile.Fil: Ellis, Barbara A. Centers for Disease Control and Prevention; Estados Unidos.Fil: Pavletic, Carlos. Ministry of Health; Chile.Fil: Cerda, Rodrigo. Pan American Health Organization; Chile.Fil: Zaki, Sherif. Centers for Disease Control and Prevention; Estados Unidos.Fil: Wun-Ju, Shieh. Centers for Disease Control and Prevention; Estados Unidos.Fil: Meyer, Richard. Centers for Disease Control and Prevention; Estados Unidos.Fil: Tapia, Mauricio. Coyhaique Regional Hospital; Chile.Fil: Mansilla, Carlos. Coyhaique Regional Hospital; Chile.Fil: Baro, Michel. Llanchipal Health Services; Chile.Fil: Vergara, Jose A. Llanchipal Health Services; Chile.Fil: Concha, Marisol. Ministry of Health; Chile.Fil: Calderón, Gladys. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio Maiztegui; Argentina.Fil: Enria, Delia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio Maiztegui; Argentina.Fil: Peters, C.J. Centers for Disease Control and Prevention; Estados Unidos.Fil: Ksiazek, Thomas G. Centers for Disease Control and Prevention; Estados Unidos.An outbreak of 25 cases of Andes virus-associated hantavirus pulmonary syndrome (HPS) was recognized in southern Chile from July 1997 through January 1998. In addition to the HPS patients, three persons with mild hantaviral disease and one person with asymptomatic acute infection were identified. Epidemiologic studies suggested person-to-person transmission in two of three family clusters. Ecologic studies showed very high densities of several species of sigmodontine rodents in the area

An outbreak of hantavirus pulmonary syndrome, Chile, 1997

Fil: Toro, Jorge. Ministry of Health; Chile.Fil: Vega, Jeanette D. Pan American Health Organization; Chile.Fil: Khan, Ali S. Centers for Disease Control and Prevention; Estados Unidos.Fil: Mills, James N. Centers for Disease Control and Prevention; Estados Unidos.Fil: Padula, Paula. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Terry, William. Centers for Disease Control and Prevention; Estados Unidos.Fil: Yadón, Zaida. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Valderrama, Rosa. Aysen Region XI Health Service; Chile.Fil: Ellis, Barbara A. Centers for Disease Control and Prevention; Estados Unidos.Fil: Pavletic, Carlos. Ministry of Health; Chile.Fil: Cerda, Rodrigo. Pan American Health Organization; Chile.Fil: Zaki, Sherif. Centers for Disease Control and Prevention; Estados Unidos.Fil: Wun-Ju, Shieh. Centers for Disease Control and Prevention; Estados Unidos.Fil: Meyer, Richard. Centers for Disease Control and Prevention; Estados Unidos.Fil: Tapia, Mauricio. Coyhaique Regional Hospital; Chile.Fil: Mansilla, Carlos. Coyhaique Regional Hospital; Chile.Fil: Baro, Michel. Llanchipal Health Services; Chile.Fil: Vergara, Jose A. Llanchipal Health Services; Chile.Fil: Concha, Marisol. Ministry of Health; Chile.Fil: Calderón, Gladys. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio Maiztegui; Argentina.Fil: Enria, Delia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio Maiztegui; Argentina.Fil: Peters, C.J. Centers for Disease Control and Prevention; Estados Unidos.Fil: Ksiazek, Thomas G. Centers for Disease Control and Prevention; Estados Unidos.An outbreak of 25 cases of Andes virus-associated hantavirus pulmonary syndrome (HPS) was recognized in southern Chile from July 1997 through January 1998. In addition to the HPS patients, three persons with mild hantaviral disease and one person with asymptomatic acute infection were identified. Epidemiologic studies suggested person-to-person transmission in two of three family clusters. Ecologic studies showed very high densities of several species of sigmodontine rodents in the area

Understanding Intergenerational Conflict

Understanding Intergenerational Conflict This presentation will introduce findings of current research being completed here are Western Oregon University. The focus of the research is on patterns of conflict among Latinx that may come from cultural expectations. We will explore if the presence of conflict is perceived differently among those coming from a collectivistic culture and potential conflicts between emerging adults and parents. We discuss with students how these conflicts affect relationships and consequences that may emerge. As well as explore our ethnic cultural norms and experiences with conflict and non-family related issues and challenges. In addition to exploring possible conflicts the Latinx population may experience we will provide psychoeducation and coping skills that can support mental health when facing conflict

EXPLORING THE RELATIONSHIP BETWEEN PHYSICAL LITERACY LEVELS, ENGAGEMENT AND EMOTIONALITY IN PHYSICAL EDUCATION CLASSES

ABSTRACT For the researchers, physical literacy (AFi) is the objective to be achieved in Physical Education, for seeking competent subjects, capable of adhering to physical activity throughout their lives, with continuous personal, social, affective, and physical development. Quantitative, descriptive-correlational research was carried out, with a non-experimental design and a non-probabilistic sample of 322 subjects, students from 12 to 18 years old from private, public, and subsidized schools in Talca, Chile. The aim was to relate the level of AFi, engagement and perceived emotionality. Data were collected by the Perceived Physical Literacy Instrument (PPLI), Behavioral Engagement Questionnaire (BEQ) and Scale for Mood Assessment (EVEA). A positive relationship was identified with a higher level of physical literacy, higher levels of happiness (r=0.37) and emotional engagement (r=0.54), decreasing the indexes of hostility (r=-0.25) and the private establishments reach the highest levels of anxiety (X̅=3.2). It is concluded that the higher the level of AFi, the greater the commitment and the greater the regulation of emotional factors