977 research outputs found

    The Efficacy and Impact of the Alien Transfer Exit Programme: Migrant Perspectives from Nogales, Sonora, Mexico

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    The Alien Transfer Exit Programme ( ATEP ) is a US deportation strategy created in 2008 whereby migrants are returned to border regions of Mexico distant from their initial place of apprehension. The goal of this strategy is to geographically separate migrants from their coyotes [paid crossing guide], who are often waiting for them in Mexico, in an attempt to discourage people from attempting additional border crossings. The official government stance concerning this programme is that it is both effective at deterring migration and that it protects migrants from abusive coyotes who often “force” them to cross the harsh Sonoran desert. The effectiveness of this new policy or its impact on the experiences of migrants has yet to be examined. Using a combination of ethnography and archaeology, I describe ATEP and its impacts on the social process of border crossing with an emphasis on the experiences of migrants who have been deported from California to the Mexican border town of Nogales. I argue that recent formalized deportation strategies such as ATEP build on previous lateral relocation programmes that have long been ineffective at slowing migration. In addition, ATEP contributes to sustaining previous migration control policies of exclusion (based on age, gender, and health) that now produce new dangers for both those included and excluded from this programme. ATEP should be viewed as an enforcement strategy aimed at systematically placing migrants in harm's way by relocating them geographically and by undermining the resources (i.e., human and social capital) that people have come to rely on for successful (and safer) border crossings. These findings contribute to the growing literature on the anthropology of deportation and the critical phenomenology of illegality.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97258/1/imig12062.pd

    Animal Scavenging and Scattering and the Implications for Documenting the Deaths of Undocumented Border Crossers in the Sonoran Desert,

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    Since 1998, over 5500 people have died while attempting to cross the U.S.–Mexico border without authorization. These deaths have primarily occured in the Arizona desert. Despite the high volume of deaths, little experimental work has been conducted on Sonoran Desert taphonomy. In this study, pig carcasses were used as proxies for human remains and placed in different depositional contexts (i.e., direct sunlight and shade) that replicate typical sites of migrant death. Decomposition was documented through daily site visits, motion‐sensitive cameras and GIS mapping, while skeletal preservation was investigated through the collection of the remains and subsequent faunal analysis. Our results suggest that vultures and domestic dogs are underappreciated members of the Sonoran scavenging guild and may disperse skeletal remains and migrant possessions over 25 m from the site of death. The impact of scavengers and the desert environment on the decomposition process has significant implications for estimating death rates and identifying human remains along the Arizona/Mexico border.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110576/1/jfo12597.pd

    Rhipicephalus microplus salivary gland molecules induce differential CD86 expression in murine macrophages

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    <p>Abstract</p> <p>Background</p> <p>Tick parasitism is a major impediment for cattle production in many parts of the world. The southern cattle tick, <it>Rhipicephalus </it>(<it>Boophilus</it>) <it>microplus</it>, is an obligate hematophagous parasite of domestic and wild animals that serves as vector of infectious agents lethal to cattle. Tick saliva contains molecules evolved to modulate host innate and adaptive immune responses which facilitates blood feeding and pathogen transmission. Tick feeding promotes CD4 T cell polarization to a Th2 profile usually accompanied by down-regulation of Th1 cytokines through as yet undefined mechanisms. Co-stimulatory molecules on antigen presenting cells are central to development of T cell responses including Th1 and Th2 responses. Tick induced changes to antigen presenting cell signal transduction pathways are largely unknown. Here we document the ability of <it>R</it>. <it>microplus </it>salivary gland extracts (SGE) to effect differential CD86 expression.</p> <p>Results</p> <p>We examined changes in co-stimulatory molecule expression in murine RAW 264.7 cells in response to <it>R</it>. <it>microplus </it>SGE exposure in the presence of the toll-like receptor 4 (TLR4) ligand, LPS. After 24 hrs, CD86, but not CD80, was preferentially up-regulated on mouse macrophage RAW 264.7 cells when treated with SGE and then LPS, but not SGE alone. CD80 and CD40 expression was increased with LPS, but the addition of SGE did not alter expression. Higher concentrations of SGE were less effective at increasing CD86 RNA expression. The addition of mitogen or extracellular kinase (MEK) inhibitor, PD98059, significantly reduced the ability for SGE to induce CD86 expression, indicating activation of MEK is necessary for SGE induced up-regulation.</p> <p>Conclusions</p> <p>Molecules in SGE of <it>R. microplus </it>have a concentration-dependent effect on differential up-regulation of CD86 in a macrophage cell line activated by the TLR4 ligand, LPS. This CD86 up-regulation is at least partially dependent on the ERK1/2 pathway and may serve to promote Th2 polarization of the immune response.</p

    Intraspecific venom variation of Mexican West Coast Rattlesnakes (Crotalus basiliscus) and its implications for antivenom production

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    14 páginas, 9 figuras, 3 tablasIntraspecific variation in snake venoms has been widely documented worldwide. However, there are few studies on this subject in Mexico. Venom characterization studies provide important data used to predict clinical syndromes, to evaluate the efficacy of antivenoms and, in some cases, to improve immunogenic mixtures in the production of antivenoms. In the present work, we evaluated the intraspecific venom variation of Crotalus basiliscus, a rattlesnake of medical importance and whose venom is used in the immunization of horses to produce one of the Mexican antivenoms. Our results demonstrate that there is variation in biological and biochemical activities among adult venoms and that there is an ontogenetic change from juvenile to adult venoms. Juvenile venoms were more lethal and had higher percentages of crotamine and crotoxin, while adult venoms had higher percentages of snake venom metalloproteases (SVMPs). Additionally, we documented crotoxin-like PLA2 variation in which specimens from Zacatecas, Sinaloa and Michoacán (except 1) lacked the neurotoxin, while the rest of the venoms had it. Finally, we evaluated the efficacy of three lots of Birmex antivenom and all three were able to neutralize the lethality of four representative venoms but were not able to neutralize crotamine. We also observed significant differences in the LD50 values neutralized per vial among the different lots. Based on these results, we recommend including venoms containing crotamine in the production of antivenom for a better immunogenic mixture and to improve the homogeneity of lots.This study was financially supported by DGAPA-PAPIIT (project IN211621), CONACYT (project264255); FORDECYT PRONACE (project 1715618/2020), FORDECYT (project 303045), Clemson University and the National Science Foundation (DEB 1822417) to CLP.Peer reviewe
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