3 resultados para Normally Open and Closed Switch
em DigitalCommons@The Texas Medical Center
Resumo:
Background. Human trafficking, or "modern day slavery", is a complex public health issue that we must understand more fully before it can be effectively tackled. There have been very few empirical studies on human trafficking and estimates of global and national human trafficking victims vary widely. Free the Slaves, a non-profit organization, estimates that there are at least 27 million people in the world at any given time that can be classified as victims of human trafficking. Houston, Texas has been identified as a place where human trafficking may be more likely to exist due to its close proximity to Mexico and due to economic and population factors. Houston Rescue and Restore Coalition (HRRC) is a local organization that exists to raise awareness of human trafficking in Houston, Texas. To better serve victims of human trafficking, HRRC commissioned a community assessment of the services available to victims of human trafficking in the greater Houston metropolitan area.^ Purpose. The current study assessed the capacity of organizations and agencies within the greater Houston metropolitan area to deal with human trafficking issues; in particular, knowledge regarding human trafficking issues among these organizations and agencies was evaluated.^ Methods. A cross-sectional study design was used to conduct surveys with key informants/stakeholders from organizations and agencies within the greater Houston metropolitan area. The survey instrument included 41 items in three parts, and consisted of multiple choice questions, open-ended essay questions, and closed-ended 5 point Likert questions.^ Results. The findings from this study indicate that efforts must be made to increase comprehensive awareness of the issue of human trafficking, including the federal and state laws that have been enacted to combat this problem. The data also indicate that there are limited services provided to human trafficking victims within the greater Houston metropolitan area.^ Conclusion. The results of the survey will provide Houston Rescue and Restore Coalition with information that will assist them in targeting their efforts to combat human trafficking in Houston, Texas.^
Resumo:
The myocyte enhancer factor (MEF)-2 family of transcription factors has been implicated in the regulation of muscle transcription in vertebrates, but the precise position of these regulators within the genetic hierarchy leading to myogenesis is unclear. The MEF2 proteins bind to a conserved A/T-rich DNA sequence present in numerous muscle-specific genes, and they are expressed in the cells of the developing somites and in the embryonic heart at the onset of muscle formation in mammals. The MEF2 genes belong to the MADS box family of transcription factors, which control specific programs of gene expression in species ranging from yeast to humans. Each MEF2 family member contains two highly conserved protein motifs, the MADS domain and the MEF2-specific domain, which together provide the MEF2 factors with their unique DNA binding and dimerization properties. In an effort to further define the function of the MEF2 proteins, and to evaluate the degree of conservation shared among these factors and the phylogenetic pathways that they regulate, we sought to identify MEF2 family members in other species. In Drosophila, a homolog of the vertebrate MEF2 genes was identified and termed D-mef2. The D-MEF2 protein binds to the consensus MEF2 element and can activate transcription through tandem copies of that site. During Drosophila embryogenesis, D-MEF2 is specific to the mesoderm germ layer of the developing embryo and becomes expressed in all muscle cell types within the embryo. The role of D-mef2 in Drosophila embryogenesis was examined by generating a loss-of-function mutation in the D-mef2 gene. In embryos homozygous for this mutant allele, somatic, cardiac, and visceral muscles fail to differentiate, but precursors of these myogenic lineages are normally specified and positioned. These results demonstrate that different muscle cell types share a common myogenic differentiation program controlled by MEF2 and suggest that this program has been conserved from Drosophila to mammals. ^
Resumo:
Cart1 is a paired-class homeobox-containing gene that is expressed in head mesenchyme, branchial arches, limb buds, and various cartilages during embryogenesis. To understand the role of Cart1 during mammalian development, I generated Cart1-mutant mice by gene targeting in mouse embryonic stem cells. Cart1-homozygous mutants were born alive but all died soon after birth. Most had acrania (absence of the cranial vault) and meroanencephaly (absence of part of the brain). In situ hybridization studies showed that Cart1 is expressed specifically in forebrain mesenchyme but not in midbrain or hindbrain mesenchyme nor in the neural tube. Developmental studies revealed a transient deficiency of forebrain mesenchyme cells due to apoptosis associated with a delay in neural tube closure in that region. Subsequently, the forebrain region became filled with mesenchyme and closed, however, the midbrain neural tube region never initiated closure and remained open. These results suggest that Cart1 is required for the survival of forebrain mesenchyme and that its absence disrupts cranial neural tube morphogenesis by blocking the initiation of closure in the midbrain region, and this ultimately leads to the generation of lethal craniofacial defects. Prenatal treatment of Cart1 homozygous mutants with folic acid suppressed the development of the acrania/meroanencephaly phenotype. Thus, Cart1 mutant mice provide a novel animal model for understanding the cellular, molecular, and genetic etiology of neural tube defects and for the development of prenatal therapeutic protocols using folic acid. ^