250 research outputs found

    Security sector reform in Africa: donor approaches versus local needs

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    Many African states have security sector reform (SSR) programs. These are often internationally funded. But how do such programs account for previously existing security institutions and the security needs of local communities? This article examines SSR all over Africa to assess local ownership and path dependency from a New Institutionalist perspective. It finds that SSR, particularly in post-conflict countries, tends to be driven by ideas and perceptions of international donors promoting generalized blueprints. Often, such programs only account in a very limited way for path-dependent aspects of security institutions or the local context. Hence the reforms often lack local participation and are thus not accepted by the local community eventually

    No First-Order Phase Transition in the Gross-Neveu Model?

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    Within a variational calculation we investigate the role of baryons for the structure of dense matter in the Gross-Neveu model. We construct a trial ground state at finite baryon density which breaks translational invariance. Its scalar potential interpolates between widely spaced kinks and antikinks at low density and the value zero at infinite density. Its energy is lower than the one of the standard Fermi gas at all densities considered. This suggests that the discrete gamma_5 symmetry of the Gross-Neveu model does not get restored in a first order phase transition at finite density, at variance with common wisdom.Comment: 16 pages, 7 figures, LaTe

    Social and health epidemiology of immigrants in Germany: past, present and future

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    Razum O, Wenner J. Social and health epidemiology of immigrants in Germany: past, present and future. Public Health Reviews. 2016;37(1): 4.Germany has experienced different forms of immigration for many decades. At the end of and after the Second World War, refugees, displaced persons and German resettlers constituted the largest immigrant group. In the 1950s, labor migration started, followed by family reunification. There has been a constant migration of refugees and asylum seekers reaching peaks in the early 1990s as well as today. Epidemiological research has increasingly considered the health, and the access to health care, of immigrants and people with migration background. In this narrative review we discuss the current knowledge on health of immigrants in Germany. The paper is based on a selective literature research with a focus on studies using representative data from the health reporting system. Our review shows that immigrants in Germany do not suffer from different diseases than non-immigrants, but they differ in their risk for certain diseases, in the resources to cope with theses risk and regarding access to treatment. We also identified the need for differentiation within the immigrant population, considering among others social and legal status, country of origin and duration of stay. Though most of the studies acknowledge the need for differentiation, the lack of data currently rules out analyses accounting for the existing diversity and thus a full understanding of health inequalities related to migration to Germany

    HIT family genes: FHIT but not PKCI-1/HINT produces altered transcripts in colorectal cancer

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    Forty-five colorectal adenocarcinomas were examined for alterations in the HIT family genes FHIT and PKCI-1/HINT by a combination of reverse transcriptase polymerase chain reaction and DNA sequencing. In all cases a single transcript corresponding to the reported sequence was detected using primers specific for the PKCI-1/HINT gene. In contrast multiple transcripts were detected using primers specific for the FHIT gene transcript. 6% (3/45) of tumours evinced no detectable expression of any FHIT transcript and a further 12% (6/45) produced only the normal full length transcripts. Ninety-six aberrant transcripts were characterized from the remaining tumours. Deviations from the normal full length sequence characterized included deletions, insertions of novel sequences, a point mutation as well as the usage of a putative alternate splice site in exon 10. Message variants were detected with approximately equal frequency in all tumour stages with the exception that templates with insertions were found solely in Dukes’ stage B tumours (P < 0.001). With the exception of the putative alternate splice site, aberrant transcripts were not detected in matched normal mucosa. These results suggest that members of the HIT family of genes are only selectively involved in tumorigenesis and that perturbation of FHIT gene expression is an early event in colorectal tumorigenesis. © 1999 Cancer Research Campaig

    Culturing Aerobic and Anaerobic Bacteria and Mammalian Cells with a Microfluidic Differential Oxygenator

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    In this manuscript, we report on the culture of anaerobic and aerobic species within a disposable multilayer polydimethylsiloxane (PDMS) microfluidic device with an integrated differential oxygenator. A gas-filled microchannel network functioning as an oxygen−nitrogen mixer generates differential oxygen concentration. By controlling the relative flow rate of the oxygen and nitrogen input gases, the dissolved oxygen (DO) concentration in proximal microchannels filled with culture media are precisely regulated by molecular diffusion. Sensors consisting of an oxygen-sensitive dye embedded in the fluid channels permit dynamic fluorescence-based monitoring of the DO concentration using low-cost light-emitting diodes. To demonstrate the general utility of the platform for both aerobic and anaerobic culture, three bacteria with differential oxygen requirements (E. coli, A. viscosus, and F. nucleatum), as well as a model mammalian cell line (murine embryonic fibroblast cells (3T3)), were cultured. Growth characteristics of the selected species were analyzed as a function of eight discrete DO concentrations, ranging from 0 ppm (anaerobic) to 42 ppm (fully saturated)

    Molecule-Electrode Interface Energetics in Molecular Junction: a Transition Voltage Spectroscopy Study

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    We assess the performances of the transition voltage spectroscopy (TVS) method to determine the energies of the molecular orbitals involved in the electronic transport though molecular junctions. A large number of various molecular junctions made with alkyl chains but with different chemical structure of the electrode-molecule interfaces are studied. In the case of molecular junctions with clean, unoxidized electrode-molecule interfaces, i.e. alkylthiols and alkenes directly grafted on Au and hydrogenated Si, respectively, we measure transition voltages in the range 0.9 - 1.4 V. We conclude that the TVS method allows estimating the onset of the tail of the LUMO density of states, at energy located 1.0 - 1.2 eV above the electrode Fermi energy. For oxidized interfaces (e.g. the same monolayer measured with Hg or eGaIn drops, or monolayers formed on a slightly oxidized silicon substrate), lower transition voltages (0.1 - 0.6 V) are systematically measured. These values are explained by the presence of oxide-related density of states at energies lower than the HOMO-LUMO of the molecules. As such, the TVS method is a useful technique to assess the quality of the molecule-electrode interfaces in molecular junctions.Comment: Accepted for publication in J. Phys. Chem C. One pdf file including manuscript, figures and supporting informatio

    State-building, war and violence : evidence from Latin America

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    In European history, war has played a major role in state‐building and the state monopoly on violence. But war is a very specific form of organized political violence, and it is decreasing on a global scale. Other patterns of armed violence now dominate, ones that seem to undermine state‐building, thus preventing the replication of European experiences. As a consequence, the main focus of the current state‐building debate is on fragility and a lack of violence control inside these states. Evidence from Latin American history shows that the specific patterns of the termination of both war and violence are more important than the specific patterns of their organization. Hence these patterns can be conceptualized as a critical juncture for state‐building. While military victories in war, the subordination of competing armed actors and the prosecution of perpetrators are conducive for state‐building, negotiated settlements, coexistence, and impunity produce instability due to competing patterns of authority, legitimacy, and social cohesion

    DMA, a Bisbenzimidazole, Offers Radioprotection by Promoting NFκB Transactivation through NIK/IKK in Human Glioma Cells

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    BACKGROUND: Ionizing radiation (IR) exposure often occurs for human beings through occupational, medical, environmental, accidental and/or other sources. Thus, the role of radioprotector is essential to overcome the complex series of overlapping responses to radiation induced DNA damage. METHODS AND RESULTS: Treatment of human glioma U87 cells with DMA (5- {4-methylpiperazin-1-yl}-2-[2'-(3, 4-dimethoxyphenyl)-5'-benzimidazolyl] in the presence or absence of radiation uncovered differential regulation of an array of genes and proteins using microarray and 2D PAGE techniques. Pathway construction followed by relative quantitation of gene expression of the identified proteins and their interacting partners led to the identification of MAP3K14 (NFκB inducing kinase, NIK) as the candidate gene affected in response to DMA. Subsequently, over expression and knock down of NIK suggested that DMA affects NFκB inducing kinase mediated phosphorylation of IKKα and IKKβ both alone and in the presence of ionizing radiation (IR). The TNF-α induced NFκB dependent luciferase reporter assay demonstrated 1.65, 2.26 and 3.62 fold increase in NFκB activation at 10, 25 and 50 µM DMA concentrations respectively, compared to control cells. This activation was further increased by 5.8 fold in drug + radiation (50 µM +8.5 Gy) treated cells in comparison to control. We observed 51% radioprotection in control siRNA transfected cells that attenuated to 15% in siRNA NIK treated U87 cells, irradiated in presence of DMA at 24 h. CONCLUSIONS: Our studies show that NIK/IKK mediated NFκB activation is more intensified in cells over expressing NIK and treated with DMA, alone or in combination with ionizing radiation, indicating that DMA promotes NIK mediated NFκB signaling. This subsequently leads to the radioprotective effect exhibited by DMA
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