141 research outputs found

    Calcium/calmodulin-dependent phosphorylation of vimentin in rat sertoli cells.

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    Ca2+-dependent protein phosphorylation and the role of calmodulin in this process was investigated in subcellular fractions of primary cultures of rat Sertoli cells. Significant Ca2+/calmodulin-dependent protein phosphorylation in Sertoli cells was restricted to the cytosol fraction. The calmodulin dependence of these effects was confirmed by using the calmodulin inhibitor trifluoperazine. One of the Ca2+/calmodulin-dependent phosphoproteins was identified as the intermediate filament protein vimentin, based on the following criteria: (i) migration pattern in two-dimensional polyacrylamide gels, (ii) Ca2+/calmodulin-dependent phosphorylation of a 58-kilodalton protein present in detergent-insoluble intermediate filament protein extract of Sertoli cells, and (iii) peptide mapping of the phosphoprotein. These data support a role for Ca2+/calmodulin-dependent protein phosphorylation in the modulation of Sertoli cell cytoskeletal components

    Successes, challenges and lessons learned: Community-engaged research with South Carolina's Gullah population

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    Engaging communities is highly recommended in the conduct of health research among vulnerable populations. The strength of community-engaged research is well documented and is recognised as a useful approach for eliminating health disparities and improving health equity. In this article, five interdisciplinary teams from the Medical University of South Carolina present their involvement with community-engaged research with a unique population of Gullah African Americans residing in rural South Carolina. Their work has been integrated with the nine established principles of community-engaged research: establishing clear goals, becoming knowledgeable about the community, establishing relationships, developing community self-determination, partnering with the community, maintaining respect, mobilising community assets, releasing control, and maintaining community collaboration. In partnership with a Citizen Advisory Committee, developed at the inception of the first community-engaged research project, the academic researchers have been able to build on relationships and trust with this population to sustain partnerships and to meet major research objectives over a 20-year period. Challenges observed include structural inequality, organisational and cultural issues, and lack of resources for building sustainable research infrastructure. Lessons learned during this process include the necessity for clearly articulated and shared goals, knowledge about the community culture, and embedding the cultural context within research approaches. Keywords: Engaged health research, vulnerable populations, longterm collaboration, South Carolina 'Gullah' communitie

    Genome-Wide Linkage Scan in Gullah-Speaking African American Families With Type 2 Diabetes: The Sea Islands Genetic African American Registry (Project SuGAR)

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    OBJECTIVE—The Gullah-speaking African American population from the Sea Islands of South Carolina is characterized by a low degree of European admixture and high rates of type 2 diabetes and diabetic complications. Affected relative pairs with type 2 diabetes were recruited through the Sea Islands Genetic African American Registry (Project SuGAR)

    Arthropod Phylogenetics in Light of Three Novel Millipede (Myriapoda: Diplopoda) Mitochondrial Genomes with Comments on the Appropriateness of Mitochondrial Genome Sequence Data for Inferring Deep Level Relationships

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    Background Arthropods are the most diverse group of eukaryotic organisms, but their phylogenetic relationships are poorly understood. Herein, we describe three mitochondrial genomes representing orders of millipedes for which complete genomes had not been characterized. Newly sequenced genomes are combined with existing data to characterize the protein coding regions of myriapods and to attempt to reconstruct the evolutionary relationships within the Myriapoda and Arthropoda. Results The newly sequenced genomes are similar to previously characterized millipede sequences in terms of synteny and length. Unique translocations occurred within the newly sequenced taxa, including one half of the Appalachioria falcifera genome, which is inverted with respect to other millipede genomes. Across myriapods, amino acid conservation levels are highly dependent on the gene region. Additionally, individual loci varied in the level of amino acid conservation. Overall, most gene regions showed low levels of conservation at many sites. Attempts to reconstruct the evolutionary relationships suffered from questionable relationships and low support values. Analyses of phylogenetic informativeness show the lack of signal deep in the trees (i.e., genes evolve too quickly). As a result, the myriapod tree resembles previously published results but lacks convincing support, and, within the arthropod tree, well established groups were recovered as polyphyletic. Conclusions The novel genome sequences described herein provide useful genomic information concerning millipede groups that had not been investigated. Taken together with existing sequences, the variety of compositions and evolution of myriapod mitochondrial genomes are shown to be more complex than previously thought. Unfortunately, the use of mitochondrial protein-coding regions in deep arthropod phylogenetics appears problematic, a result consistent with previously published studies. Lack of phylogenetic signal renders the resulting tree topologies as suspect. As such, these data are likely inappropriate for investigating such ancient relationships

    Becoming with a police dog : training technologies for bonding

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    To develop and illustrate the potential for visual methodologies in conducting multispecies ethnography, we present a case study of general‐purpose police dog training in the UK. Our argument is two‐fold: first, we draw on STS approaches and insights for looking at training activities as material and socio‐cultural devices that, we argue, constitute a training technology. Here we have been influenced by the work of Cussins and adopted her concept of “ontological choreographies” for addressing the development of the police dog–police officer bond and ability to communicate for working together. Second, we argue that visual data capture presents valuable opportunities for “less human‐centred” and more symmetrical methods to approach non‐human/more than human research subjects. We illustrate how photo diaries and video clips enabled us to remain attentive to the material and embodied practices of dog training, bringing to the fore the dogs’ actions, tools, and devices and thus enlivening the material–cultural choreographies of the training activities. In conclusion, we elucidate how this onto‐epistemological approach enabled us to investigate the material and corporeal construction of the general purpose (GP) police dog

    Hypothetical biomolecular probe based on a genetic switch with tunable symmetry and stability

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    Background: Genetic switches are ubiquitous in nature, frequently associated with the control of cellular functions and developmental programs. In the realm of synthetic biology, it is of great interest to engineer genetic circuits that can change their mode of operation from monostable to bistable, or even to multistable, based on the experimental fine-tuning of readily accessible parameters. In order to successfully design robust, bistable synthetic circuits to be used as biomolecular probes, or understand modes of operation of such naturally occurring circuits, we must identify parameters that are key in determining their characteristics. Results: Here, we analyze the bistability properties of a general, asymmetric genetic toggle switch based on a chemical-reaction kinetic description. By making appropriate approximations, we are able to reduce the system to two coupled differential equations. Their deterministic stability analysis and stochastic numerical simulations are in excellent agreement. Drawing upon this general framework, we develop a model of an experimentally realized asymmetric bistable genetic switch based on the LacI and TetR repressors. By varying the concentrations of two synthetic inducers, doxycycline and isopropyl ??-D-1-thiogalactopyranoside, we predict that it will be possible to repeatedly fine-tune the mode of operation of this genetic switch from monostable to bistable, as well as the switching rates over many orders of magnitude, in an experimental setting. Furthermore, we find that the shape and size of the bistability region is closely connected with plasmid copy number. Conclusions: Based on our numerical calculations of the LacI-TetR asymmetric bistable switch phase diagram, we propose a generic work-flow for developing and applying biomolecular probes: Their initial state of operation should be specified by controlling inducer concentrations, and dilution due to cellular division would turn the probes into memory devices in which information could be preserved over multiple generations. Additionally, insights from our analysis of the LacI-TetR system suggest that this particular system is readily available to be employed in this kind of probe.clos
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