Analyzing the function of myogenin in adult satellite cells through the construction of a myogenin conditional allele

Although mechanisms regulating the formation of embryonic skeletal muscle are well characterized, less is known about muscle formation in postnatal life. This disparity is unfortunate because the largest increases in skeletal muscle mass occur after birth. Adult muscle stem cells (satellite cells) appear to recapitulate the events that occur in embryonic myoblasts. In particular, the myogenic basic helix-loop-helix factors, which have crucial functions in embryonic muscle development, are assumed to have similar roles in postnatal muscle formation. Here, I test this assumption by determining the role of the myogenic regulator myogenin in postnatal life. Myogenin-null mice die at birth, necessitating the generation of floxed alleles of myogenin and the use of cre-recombinase lines to delete myogenin. Removing myogenin before embryonic muscle development resulted in myofiber deficiencies identical to those observed in myogenin-null mice. However, mice in which myogenin was deleted following embryonic muscle development had normal skeletal muscle, except for modest alterations in MRF4 and MyoD expression. Notably, myogenin-deleted mice were 30% smaller than controls, suggesting that myogenin's absence disrupted general body growth. These results suggest that skeletal muscle growth in postnatal life is controlled by mechanisms distinct from those occurring in embryonic muscle development. ^

Dr. William Gorgas and his style of management against yellow fever during the construction of the Panama Canal: A historical case study

This study describes the style of management of Dr. William Gorgas as he led the public health effort to reduce diseases to a level that permitted the completion of the Panama Canal construction. Initially, Gorgas was skeptical of the mosquito vector theory. He fully accepted this theory after participating in Walter Reed’s massive cleanup of Havana, Cuba during the Spanish American War of 1898. During 1905 to 1914, Gorgas was selected to lead the sanitary effort during the construction of the Panama Canal. The lessons learned from this historical case study provide public health administrators with guidance to effectively lead current and future infectious diseases threats. Understanding styles of management within the context of disease control is essential in tackling epidemics like yellow fever and other infectious diseases. ^

The social construction of infant mortality: From grassroots to medicalization

Infant mortality as a problematic situation has been recognized for some 130 years in one form or another. It has undergone various changes in its empirical dimensions relative to whom we study within the population, what we study--low birth-weight vs. pre-term births--and how we study it--whether demographically or medically. An analysis of the process by which the condition was raised by claims makers as an intolerable situation among America's urban residents reveals that demographic and medical data were sparse. Nonetheless, a judgement about the meaning and significance of the condition was made, and that interpretation led to the promulgation of systems to both document and address the condition as it has come to be defined.^ This investigation depicts the historical context and natural history of infant mortality as one of a number of social problems that came to be defined through the interplay among groups and individuals making claims and how their claims came to the public policy agenda as worthy of collective resources--who won, who lost and why. The process of social definition focuses attention on the claims makers and the ways they contrast the meaning, origins and remedies for this troubling condition. The historical context becomes the frame of reference for understanding the actions of the claims makers and the meaning and significance they attached to the problem.^ We purport that "context" provides a closer reality than disjoined "value free" accounts. Context provides the evidence for the definition, who participated in the process, why and by what means.^ The role of women in the definitional process reveals the differences in approaches utilized by the women of the settlement house reform movement and African-American women working at the grass-roots. Much of the work done by these two groups provided options to the problem's remedy; however, their differences paved the way to our current (principally medically-oriented) definition and its inherent limitations. ^

Richard Seaford. Cosmology and the Polis. The social Construction of Space and Time in the Tragedies of Aeschylus, Cambridge University Press, Cambridge, 2012, xiii + 366 pp.

Fil: Fernández Deagustini, María del Pilar. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.

The Construction of the Image of Peace in Ancient Greece : A few literary and Iconographic Evidences

El presente artículo busca identificar y analizar algunas de los principales tratamientos poéticos y artísticos del binomio paz / riqueza en una perspectiva diacrónica y comparativa, intentando aislar las más frecuentes imágenes, metáforas y epítetos relacionados con ese tema. El estudio de los pasajes elegidos deja claro cómo ambos, poetas y artistas plásticos, conocían y manipulaban con su arte un mismo patrimonio bastante antiguo

Psychosocial construction of time and social change

This paper analyzes the psychosocial construction of the conceptions of time and social change, and their relation with the notion of progress set up by modernity as well as their contradictory aspects, considering their historicity as psychosocial and social phenomena. The social construction of the notion of time is discussed; it responds to social organization forms, thus turning the social changes into historical and temporal landmarks. The association between social changes and social movements is argued and the concept of progress is deconstructed. Finally, the importance of the idea of movement in the construction of time, change and progress concepts is pointed out; it is also explained how modernity imbued such notions with direction and goals, in the direction of an arrow, according to the prevailing interests, while modeling them in its own image and likeness.

Richard Seaford. Cosmology and the Polis. The social Construction of Space and Time in the Tragedies of Aeschylus, Cambridge University Press, Cambridge, 2012, xiii + 366 pp.

Fil: Fernández Deagustini, María del Pilar. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.

The Construction of the Image of Peace in Ancient Greece : A few literary and Iconographic Evidences

El presente artículo busca identificar y analizar algunas de los principales tratamientos poéticos y artísticos del binomio paz / riqueza en una perspectiva diacrónica y comparativa, intentando aislar las más frecuentes imágenes, metáforas y epítetos relacionados con ese tema. El estudio de los pasajes elegidos deja claro cómo ambos, poetas y artistas plásticos, conocían y manipulaban con su arte un mismo patrimonio bastante antiguo

Psychosocial construction of time and social change

This paper analyzes the psychosocial construction of the conceptions of time and social change, and their relation with the notion of progress set up by modernity as well as their contradictory aspects, considering their historicity as psychosocial and social phenomena. The social construction of the notion of time is discussed; it responds to social organization forms, thus turning the social changes into historical and temporal landmarks. The association between social changes and social movements is argued and the concept of progress is deconstructed. Finally, the importance of the idea of movement in the construction of time, change and progress concepts is pointed out; it is also explained how modernity imbued such notions with direction and goals, in the direction of an arrow, according to the prevailing interests, while modeling them in its own image and likeness.

The Construction of the Image of Peace in Ancient Greece : A few literary and Iconographic Evidences

El presente artículo busca identificar y analizar algunas de los principales tratamientos poéticos y artísticos del binomio paz / riqueza en una perspectiva diacrónica y comparativa, intentando aislar las más frecuentes imágenes, metáforas y epítetos relacionados con ese tema. El estudio de los pasajes elegidos deja claro cómo ambos, poetas y artistas plásticos, conocían y manipulaban con su arte un mismo patrimonio bastante antiguo

Psychosocial construction of time and social change

This paper analyzes the psychosocial construction of the conceptions of time and social change, and their relation with the notion of progress set up by modernity as well as their contradictory aspects, considering their historicity as psychosocial and social phenomena. The social construction of the notion of time is discussed; it responds to social organization forms, thus turning the social changes into historical and temporal landmarks. The association between social changes and social movements is argued and the concept of progress is deconstructed. Finally, the importance of the idea of movement in the construction of time, change and progress concepts is pointed out; it is also explained how modernity imbued such notions with direction and goals, in the direction of an arrow, according to the prevailing interests, while modeling them in its own image and likeness.