314 research outputs found

    Disruption of muscle architecture and myocardial degeneration in mice lacking desmin.

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    Desmin, the muscle specific intermediate filament (IF) protein encoded by a single gene, is expressed in all muscle tissues. In mature striated muscle, desmin IFs surround the Z-discs, interlink them together and integrate the contractile apparatus with the sarcolemma and the nucleus. To investigate the function of desmin in all three muscle types in vivo, we generated desmin null mice through homologous recombination. Surprisingly, desmin null mice are viable and fertile. However, these mice demonstrated a multisystem disorder involving cardiac, skeletal, and smooth muscle. Histological and electron microscopic analysis in both heart and skeletal muscle tissues revealed severe disruption of muscle architecture and degeneration. Structural abnormalities included loss of lateral alignment of myofibrils and abnormal mitochondrial organization. The consequences of these abnormalities were most severe in the heart, which exhibited progressive degeneration and necrosis of the myocardium accompanied by extensive calcification. Abnormalities of smooth muscle included hypoplasia and degeneration. The present data demonstrate the essential role of desmin in the maintenance of myofibril, myofiber, and whole muscle tissue structural and functional integrity, and show that the absence of desmin leads to muscle degeneration

    Female Perpetrators in Internal Child Trafficking in China: An empirical study

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    Through an empirical study, this article explores the overall profile of female traffickers of children in China and their role and performance in the trafficking processes. Its contribution to the human-trafficking literature lies in its focus on female perpetrators in particular. The article provides an overview of the international literature on female traffickers as well as contemporary knowledge about internal child trafficking in China. Empirical data from incarcerated traffickers suggest that portraying female traffickers as active players of criminal networks obscures the structural problems affecting female child traffickers. The short-term result is that the problems of female offenders are ignored, and the long-term impact is policy making that is disconnected from the lived experiences of an important population. From a gender perspective, this study suggests that female child traffickers are offenders as well as victims of social and gender inequalities in China’s reform era. This study also proposes that internal child trafficking in China should be brought in the international and Anglo-American debates surrounding human trafficking

    Economies of (Alleged) Deviance: Sex Work and the Sport Mega Event

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    Based on ethnographic data collected during the 2014 FIFA World Cup and 2016 Olympic Games in Rio de Janeiro, Brazil, thisarticle is interested to examine urban processes which reinvent the changing (sexual) landscape. Focusing on the way (host) citiesshape sex work both imaginatively and physically, we explore the (lived) realities of neoliberal imaginaries that shape urbanspace. Often thought to exist in the urban shadow as an absent-presence in cosmopolitan processes, we demonstrate the manner inwhich sexualized and racialized women creatively resist the political and economic trajectories of neoliberal urbanism that seek toexpropriate land and dispossess certain bodies. In the context of Rio de Janeiro—as in other host cities—this is particularlyevident in the routine encounter between sexual minorities and local law enforcement. Mindful of the literature on state incursioninto social-sexual life, we remain attentive to the everyday strategies through which those deemed sexually deviant and/or victimnavigate local authorities in search of new opportunities for economic salvation in the midst of the sport mega-event

    “Extreme" porn? The implications of a label

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    Despite its prevalence, the term ‘extreme’ has received little critical attention. ‘Extremity’ is routinely employed in ways that imply its meanings are self-evident. However, the adjective itself offers no such clarity. This article focuses on one particular use of the term – ‘extreme porn’ – in order to illustrate a broader set of concerns about the pitfalls of labelling. The label ‘extreme’ is typically employed as a substitute for engaging with the term’s supposed referents (here, pornographic content). In its contemporary usage, ‘extreme’ primarily refers to a set of context-dependent judgements rather than absolute standards or any specific properties the ‘extreme’ item is alleged to have. Concurrently then, the label ‘extreme’ carries a host of implicit values, and the presumption that the term’s meanings are ‘obvious’ obfuscates those values. In the case of ‘extreme porn’, this obfuscation is significant because it has facilitated the cultural and legal suppression of pornography

    “The Good into the Pot, the Bad into the Crop!”—A New Technology to Free Stem Cells from Feeder Cells

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    A variety of embryonic and adult stem cell lines require an intial co-culturing with feeder cells for non-differentiated growth, self renewal and maintenance of pluripotency. However for many downstream ES cell applications the feeder cells have to be considered contaminations that might interfere not just with the analysis of experimental data but also with clinical application and tissue engineering approaches. Here we introduce a novel technique that allows for the selection of pure feeder-freed stem cells, following stem cell proliferation on feeder cell layers. Complete and reproducible separation of feeder and embryonic stem cells was accomplished by adaptation of an automated cell selection system that resulted in the aspiration of distinct cell colonies or fraction of colonies according to predefined physical parameters. Analyzing neuronal differentiation we demonstrated feeder-freed stem cells to exhibit differentiation potentials comparable to embryonic stem cells differentiated under standard conditions. However, embryoid body growth as well as differentiation of stem cells into cardiomyocytes was significantly enhanced in feeder-freed cells, indicating a feeder cell dependent modulation of lineage differentiation during early embryoid body development. These findings underline the necessity to separate stem and feeder cells before the initiation of in vitro differentiation. The complete separation of stem and feeder cells by this new technology results in pure stem cell populations for translational approaches. Furthermore, a more detailed analysis of the effect of feeder cells on stem cell differentiation is now possible, that might facilitate the identification and development of new optimized human or genetically modified feeder cell lines

    The Coiled Coils of Cohesin Are Conserved in Animals, but Not In Yeast

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    The SMC proteins are involved in DNA repair, chromosome condensation, and sister chromatid cohesion throughout Eukaryota. Long, anti-parallel coiled coils are a prominent feature of SMC proteins, and are thought to serve as spacer rods to provide an elongated structure and to separate domains. We reported recently that the coiled coils of mammalian condensin (SMC2/4) showed moderate sequence divergence (approximately 10-15%) consistent with their functioning as spacer rods. The coiled coils of mammalian cohesins (SMC1/3), however, were very highly constrained, with amino acid sequence divergence typically <0.5%. These coiled coils are among the most highly conserved mammalian proteins, suggesting that they make extensive contacts over their entire surface.Here, we broaden our initial analysis of condensin and cohesin to include additional vertebrate and invertebrate organisms and multiple species of yeast. We found that the coiled coils of SMC1/3 are highly constrained in Drosophila and other insects, and more generally across all animal species. However, in yeast they are no more constrained than the coils of SMC2/4 and Ndc80/Nuf2p, suggesting that they are serving primarily as spacer rods.SMC1/3 functions for sister chromatid cohesion in all species. Since its coiled coils apparently serve only as spacer rods in yeast, it is likely that this is sufficient for sister chromatid cohesion in all species. This suggests an additional function in animals that constrains the sequence of the coiled coils. Several recent studies have demonstrated that cohesin has a role in gene expression in post-mitotic neurons of Drosophila, and other animal cells. Some variants of human Cornelia de Lange Syndrome involve mutations in human SMC1/3. We suggest that the role of cohesin in gene expression may involve intimate contact of the coiled coils of SMC1/3, and impose the constraint on sequence divergence
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