152 research outputs found
Foreword: Citizenship and Its Discontents - Centering the Immigrant in the Inter/National Imagination (Part II)
A couple of years ago, the Immigration and Naturalization Service (INS) swept through several southern states to round up and deport undocumented workers. The sweep was called Operation SouthPAW, PAW standing for Protecting America\u27s Workers. The roundup occurred in two phases, which curiously took place mostly before and after the harvest. The operation was celebrated by the INS and mainstream media as hugely successful in protecting America\u27s workers (and thus America) from encroachment by unauthorized workers. But who gains ideologically and materially from such policing actions? Who loses? These questions of material profit and ideological benefit lie at the heart of this Symposium. The papers in this Symposium investigate the aporetic relations among the nation-state, liberal understandings of citizenship, and problematic constructions of race and ethnicity as they are applied to immigrants. By centering the immigrant in a discussion of citizenship, we aim to highlight the links between the international and intranational spheres. Focusing on the Inter/national demonstrates that the traditional enlightenment-based liberal vision of a world composed of bounded and sovereign nation- states conceals as much as it purports to reveal about the movements of people, citizens and otherwise, across the nation-states\u27 bounded peripheries. The Symposium participants address three overlapping clusters of issues and ideas: (1) the interaction of citizenship, immigration, and race from a U.S. vantage point; (2) a refraining of race, slavery, and the colonial encounter both inside and outside of the U.S. context; and (3) the interrelationship of transnational flows of capital and information and the increasing flow of persons across national boundaries. At the close of the twentieth century, increasing migrations of persons are straining traditional concepts of the imagined community of the nation-state as well as the imagined community among nation-states. Each piece in this Symposium attempts to center the immigrant by examining individual and group agency within these changing communities
Excessive visual crowding effects in developmental dyscalculia
Visual crowding refers to the inability to identify objects when surrounded by other similar items. Crowding-like mechanisms are thought to play a key role in numerical perception by determining the sensory mechanisms through which ensembles are perceived. Enhanced visual crowding might hence prevent the normal development of a system involved in segregating and perceiving discrete numbers of items and ultimately the acquisition of more abstract numerical skills. Here, we investigated whether excessive crowding occurs in developmental dyscalculia (DD), a neurodevelopmental disorder characterized by difficulty in learning the most basic numerical and arithmetical concepts, and whether it is found independently of associated major reading and attentional difficulties. We measured spatial crowding in two groups of adult individuals with DD and control subjects. In separate experiments, participants were asked to discriminate the orientation of a Gabor patch either in isolation or under spatial crowding. Orientation discrimination thresholds were comparable across groups when stimuli were shown in isolation, yet they were much higher for the DD group with respect to the control group when the target was crowded by closely neighbouring flanking gratings. The difficulty in discriminating orientation (as reflected by the combination of accuracy and reaction times) in the DD compared to the control group persisted over several larger target flanker distances. Finally, we found that the degree of such spatial crowding correlated with impairments in mathematical abilities even when controlling for visual attention and reading skills. These results suggest that excessive crowding effects might be a characteristic of DD, independent of other associated neurodevelopmental disorders
Reduced 2D form coherence and 3D structure from motion sensitivity in developmental dyscalculia
Developmental dyscalculia (DD) is a specific learning disability affecting the development of numerical and arithmetical skills. The origin of DD is typically attributed to the suboptimal functioning of key regions within the dorsal visual stream (parietal cortex) which support numerical cognition. While DD individuals are often impaired in visual numerosity perception, the extent to which they also show a wider range of visual dysfunctions is poorly documented. In the current study we measured sensitivity to global motion (translational and flow), 2D static form (Glass patterns) and 3D structure from motion in adults with DD and control subjects. While sensitivity to global motion was comparable across groups, thresholds for static form and structure from motion were higher in the DD compared to the control group, irrespective of associated reading impairments. Glass pattern sensitivity predicted numerical abilities, and this relation could not be explained by recently reported differences in visual crowding. Since global form sensitivity has often been considered an index of ventral stream function, our findings could indicate a cortical dysfunction extending beyond the dorsal visual stream. Alternatively, they would fit with a role of parietal cortex in form perception under challenging conditions requiring multiple element integration
Molecular characterization of extended spectrum beta-lactamase among clinical multidrug resistant Escherichia Coli in two hospitals of Niamey, Niger
Objective: The aim of this study was to identify the multiple ESBL genes in Multidrug-resistant (MDR) Escherichia coli isolated in various biological samples in two hospitals of Niamey.Methodology: A total of 195 multidrug-resistant Escherichia coli were included in the study. These isolates were tested using polymerase chain reaction (PCR) for detection of the presence of bla CTX-M, bla TEM, bla SHV and bla OXA-1 beta-lactamase genes.Results: A total of 27.7% of Escherichia coli isolates were ESBL producing strains. Globaly, the bla TEM gene was the most prevalent (70.3%) followed by bla CTX-M (43.1%), bla OXA-1 (31.8%) and bla SHV (4.1%) genes. The four genes type of ESBL were founded simultaneously only in stool samples. Furthermore, none bla SHV gene was found in other samples type.Conclusion: This study showed the presence of various ESBL genes among clinical MDR Escherichia coli. That is why a rational use of antibiotic and appropriate methods of screening ESBL genes in routine laboratories in Niger is needed to control the ESBL genes dissemination.Keywords: MDR ,Escherichia coli, ESBL, bla genes, PCR, Niamey, Niger. Caracterisation moleculaire des betalactamases a spectre etendu chez les souches de Escherichia coli multi resistantes dans deux hopitaux de Niamey, au NigerObjectifs: Le but de cette étude était d'identifier les multiples gènes de BLSE chez les souches de Escherichia coli multi résistantes isolées de différents types d’échantillons biologiques dans deux hôpitaux de Niamey.Méthodologie : Un total de 195 Escherichia coli multi résistants a été inclus dans l'étude. Ces isolats ont été testés par la réaction de polymérase en chaîne (PCR) pour détecter la présence des gènes bla CTX-M, bla TEM, bla SHV et bla OXA-1.Résultats : Au total, 27,7% des isolats de Escherichia coli multi-résistants étaient des souches productrices de BLSE. Globalement le gène bla TEM (70,3%) était le plus détecté suivi des autres gènes bla CTX-M (43,1%), bla OXA-1 (31,8%) et bla SHV (4,1%). Notons que seul dans les échantillons de selles quatre types de gènes de BLSE ont été trouvés simultanément. Par ailleurs notons qu’aucun gène de type bla SHV n'a été trouvé dans les autres types d'échantillons.Conclusion : Cette étude avait montré la présence de divers gènes de BLSE chez les souches cliniques de Escherichia coli. C'est pourquoi une utilisation rationnelle des antibiotiques et des méthodes appropriées de dépistage des gènes de BLSE dans les laboratoires sont nécessaires afin de contrôler la diffusion des gènes de BLSE.Mots clés : Escherichia coli multi résistantes, BLSE, gènes bla, PCR, Niamey, Niger
Acute complications of preeclampsia: prognosis and management at Pikine National Hospital in Dakar (Senegal)
ABSTRACTBackground: The objective of this study was to evaluate the prevalence of acute complications of preeclampsia in order to describe the epidemiological profile of the disease, to assess its prognosis and management.Methods: This was a retrospective study of patients admitted to the Pikine National Hospital from 1 January 2010 to 31 December 2013 (48 months) with severe complicated pre-eclampsia. Included in this study were patients admitted or diagnosed with severe complicated pre-eclampsia and having given birth in the structure or not.Results: The incidence of severe preeclampsia in childbirth varied from 9.7% to 11.5% during the four years of our study. Patients were largely paucigest (55.7% of cases) and paucipares (58.5% of cases). The mean age was 28.14 years with extremes of 14 and 47 years. More than half of the patients (57.7%) were between 21 and 34 years of age. They were mostly married (90.7%). Three-quarters of the patients (76.8%) had proteinuria with ≥ 3 cross-bands. Thrombocytopenia was found in 9.7% of patients, hepatic cytolysis in 12.1%, and elevation of serum creatinine in 13.8%. The level of transaminases was found to be greater than 2 in the normal range in 12.1%. Complicated forms were the most represented in our study. These were acute complications, with 715 cases, or 57.3% of the patients. They were either isolated (52.8%) or associated (4.5%). These included eclampsia (24.9%), followed by retroplacental hematoma (24.6%), fetal death in utero (23.7%), HELLP syndrome (3.4%). , Acute edema of the lungs (1.5%), and acute renal failure (1.4%). The lethality was 2.4%. The causes of maternal death were dominated by eclampsia (14 cases), DIC (3 cases) and OAP (2 cases). We counted 77.7% of live births and a stillbirth of 254.5 ‰.Conclusions: Pre-eclampsia is a serious complication of pregnancy. Its frequency is still high in sub-Saharan Africa. In the presence of signs of severity, maternal (vital and functional) and neonatal prognosis are inevitably involved. If management is based on fetal extraction, resuscitation measures are a guarantee of maternal survival
PIP5KIβ Selectively Modulates Apical Endocytosis in Polarized Renal Epithelial Cells
Localized synthesis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] at clathrin coated pits (CCPs) is crucial for the recruitment of adaptors and other components of the internalization machinery, as well as for regulating actin dynamics during endocytosis. PtdIns(4,5)P2 is synthesized from phosphatidylinositol 4-phosphate by any of three phosphatidylinositol 5-kinase type I (PIP5KI) isoforms (α, β or γ). PIP5KIβ localizes almost exclusively to the apical surface in polarized mouse cortical collecting duct cells, whereas the other isoforms have a less polarized membrane distribution. We therefore investigated the role of PIP5KI isoforms in endocytosis at the apical and basolateral domains. Endocytosis at the apical surface is known to occur more slowly than at the basolateral surface. Apical endocytosis was selectively stimulated by overexpression of PIP5KIβ whereas the other isoforms had no effect on either apical or basolateral internalization. We found no difference in the affinity for PtdIns(4,5)P2-containing liposomes of the PtdIns(4,5)P2 binding domains of epsin and Dab2, consistent with a generic effect of elevated PtdIns(4,5)P2 on apical endocytosis. Additionally, using apical total internal reflection fluorescence imaging and electron microscopy we found that cells overexpressing PIP5KIβ have fewer apical CCPs but more internalized coated structures than control cells, consistent with enhanced maturation of apical CCPs. Together, our results suggest that synthesis of PtdIns(4,5)P2 mediated by PIP5KIβ is rate limiting for apical but not basolateral endocytosis in polarized kidney cells. PtdIns(4,5)P2 may be required to overcome specific structural constraints that limit the efficiency of apical endocytosis. © 2013 Szalinski et al
Two Distinct Integrin-Mediated Mechanisms Contribute to Apical Lumen Formation in Epithelial Cells
Background: Formation of apical compartments underlies the morphogenesis of most epithelial organs during development. The extracellular matrix (ECM), particularly the basement membrane (BM), plays an important role in orienting the apico-basal polarity and thereby the positioning of apical lumens. Integrins have been recognized as essential mediators of matrix-derived polarity signals. The importance of b1-integrins in epithelial polarization is well established but the significance of the accompanying a-subunits have not been analyzed in detail. Principal Findings: Here we demonstrate that two distinct integrin-dependent pathways regulate formation of apical lumens to ensure robust apical membrane biogenesis under different microenvironmental conditions; 1) a2b1- and a6b4integrins were required to establish a basal cue that depends on Rac1-activity and guides apico-basal cell polarization. 2) a3b1-integrins were implicated in positioning of mitotic spindles in cysts, a process that is essential for Cdc42-driven epithelial hollowing. Significance: Identification of the separate processes driven by particular integrin receptors clarifies the functional hierarchies between the different integrins co-expressed in epithelial cells and provides valuable insight into the complexity of cell-ECM interactions thereby guiding future studies addressing the molecular basis of epithelial morphogenesis durin
Beta-Lactamase-Producing Genes and Integrons in <em>Escherichia coli</em> from Diarrheal Children in Ouagadougou, Burkina Faso
This study aimed to determine the resistance of diarrheagenic Escherichia coli (DEC) strains to β-lactams antibiotics and to perform the molecular characterization of extended-spectrum β-lactamases (ESBLs) and integrons genes. It was carried out from August 2013 to October 2015 and involved 31 DEC strains isolated from diarrheal stools samples collected from children less than 5 years. The identification and characterization of DEC strains were done through the standard biochemical tests that were confirmed using API 20E and polymerase chain reaction (PCR). The antibiogram was realized by the disk diffusion method, then an amplification of the β-lactamase resistance genes and integrons by PCR was done. Out of the 419 E. coli, 31 isolates (7.4%) harbored the DEC virulence genes. From these DEC, 21 (67.7%) were ESBL-producing E. coli. Susceptibility to ESBL-producing E. coli showed that the majority of isolates were highly resistant to amoxicillin (77.4%), amoxicillin-clavulanic acid (77.4%), and piperacillin (64.5%). The following antibiotic resistance genes and integron were identified: blaTEM (6.5%), blaSHV (19.4%), blaOXA (38.7%), blaCTX-M (9.7%), Int1 (58.1%), and Int3 (19.4%). No class 2 integron (Int2) was characterized. Because of the high prevalence of multidrug-resistant ESBL organisms found, there is a need of stringent pediatric infection control measures
TRAF4 is a novel phosphoinositide-binding protein modulating tight junctions and favoring cell migration
Tumor necrosis factor (TNF) receptor-associated factor 4 (TRAF4) is frequently overexpressed in carcinomas, suggesting a specific role in cancer. Although TRAF4 protein is predominantly found at tight junctions (TJs) in normal mammary epithelial cells (MECs), it accumulates in the cytoplasm of malignant MECs. How TRAF4 is recruited and functions at TJs is unclear. Here we show that TRAF4 possesses a novel phosphoinositide (PIP)-binding domain crucial for its recruitment to TJs. Of interest, this property is shared by the other members of the TRAF protein family. Indeed, the TRAF domain of all TRAF proteins (TRAF1 to TRAF6) is a bona fide PIP-binding domain. Molecular and structural analyses revealed that the TRAF domain of TRAF4 exists as a trimer that binds up to three lipids using basic residues exposed at its surface. Cellular studies indicated that TRAF4 acts as a negative regulator of TJ and increases cell migration. These functions are dependent from its ability to interact with PIPs. Our results suggest that TRAF4 overexpression might contribute to breast cancer progression by destabilizing TJs and favoring cell migration
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