A Killing Disease Epidemic Among Displaced Sudanese Population Identified as Visceral Leishmaniasis.

A fatal disease epidemic affected the Bentiu area in southern Sudan and led to a mass migration of the Nuer tribe searching for treatment. The initially available information revealed a high mortality rate due to a possible occurrence of tuberculosis, malaria, enteric fever or visceral leishmaniasis (VL). Serological screening of 53 of the most severely affected patients in an enzyme-linked immunosorbent assay (ELISA) or an improved direct agglutination test (DAT) revealed positivity for VL. In 39 of those patients, diagnosis was confirmed by identification of Leishmania donovani amastigotes in lymph node or bone-marrow aspirates. In a total of 2714 patients observed, 1195 (44.0%) had clinical symptoms suggesting VL: DAT positive titers (1:3200-greater than or equal to 1:12800) were obtained in 654 (24.1%), of whom 325 were confirmed parasitologically. Forty-two VL cases died before or during treatment, giving a mortality rate of 6.4%. Among the intercurrent infections diagnosed in the VL population (654), respiratory involvements (31.7%) and malaria (10.7%) were most prevalent. With the exception of four (0.6%), all other VL patients (509) responded readily to sodium stibogluconate. The factors initiating the outbreak are discussed. Malnutrition and nomadic movements to potential VL endemic areas appeared to be the most important. HIV infection as a possible predisposition seemed remote considering the clinical and epidemiological similarity to VL occurring in East Africa, adequate humoral response in DAT, and immediate positive response to specific anti-Leishmania chemotherapy

A microsensor for carbonate ions suitable for microprofiling in freshwater and saline environments

A novel carbonate microsensor, based on the ion‐selective ionophore N,N,‐dioctyl‐3a,12 a‐bis(4‐trifluoroacetylbenzoxy)‐5β‐cholan‐24‐amide, is presented. The sensor chemistry and filling electrolyte, used previously for macrosensors, was improved for use in microsensors, and a simple calibration procedure was designed. The sensor is highly selective for carbonate, having a similar selectivity as the macrosensor, and is so insensitive to Cl− interference that it can be used in seawater. The ability to measure accurate profiles with the carbonate sensor was verified in agar gels with artificial carbonate gradients. Several environmental applications are presented, including photosynthesis and calcification measurements in freshwater stromatolites (tufas) and foraminifera. Carbonate profiles in illuminated and darkened hypersaline microbial mats were qualitatively as expected and aligned with the oxygen and pH profiles. The dissolved inorganic carbon profiles calculated from local pH and carbonate values, however, did not follow the expected trends, both in the foraminifera and the hypersaline mat. Temporal and spatial heterogeneities make perfect alignment of pH and carbonate profiles, needed for DIC calculations, unrealistic. The calculation of dissolved inorganic carbon microprofiles from pH and carbonate microprofiles is not recommended. The microsensor is highly useful in studies on calcification and decalcification, where direct concentrations of carbonate and calcium ions are needed

Microbial Communities Under Distinct Thermal and Geochemical Regimes in Axial and Off-Axis Sediments of Guaymas Basin

Cold seeps and hydrothermal vents are seafloor habitats fueled by subsurface energy sources. Both habitat types coexist in Guaymas Basin in the Gulf of California, providing an opportunity to compare microbial communities with distinct physiologies adapted to different thermal regimes. Hydrothermally active sites in the southern Guaymas Basin axial valley, and cold seep sites at Octopus Mound, a carbonate mound with abundant methanotrophic cold seep fauna at the Central Seep location on the northern off-axis flanking regions, show consistent geochemical and microbial differences between hot, temperate, cold seep, and background sites. The changing microbial actors include autotrophic and heterotrophic bacterial and archaeal lineages that catalyze sulfur, nitrogen, and methane cycling, organic matter degradation, and hydrocarbon oxidation. Thermal, biogeochemical, and microbiological characteristics of the sampling locations indicate that sediment thermal regime and seep-derived or hydrothermal energy sources structure the microbial communities at the sediment surface

The s Process: Nuclear Physics, Stellar Models, Observations

Nucleosynthesis in the s process takes place in the He burning layers of low mass AGB stars and during the He and C burning phases of massive stars. The s process contributes about half of the element abundances between Cu and Bi in solar system material. Depending on stellar mass and metallicity the resulting s-abundance patterns exhibit characteristic features, which provide comprehensive information for our understanding of the stellar life cycle and for the chemical evolution of galaxies. The rapidly growing body of detailed abundance observations, in particular for AGB and post-AGB stars, for objects in binary systems, and for the very faint metal-poor population represents exciting challenges and constraints for stellar model calculations. Based on updated and improved nuclear physics data for the s-process reaction network, current models are aiming at ab initio solution for the stellar physics related to convection and mixing processes. Progress in the intimately related areas of observations, nuclear and atomic physics, and stellar modeling is reviewed and the corresponding interplay is illustrated by the general abundance patterns of the elements beyond iron and by the effect of sensitive branching points along the s-process path. The strong variations of the s-process efficiency with metallicity bear also interesting consequences for Galactic chemical evolution.Comment: 53 pages, 20 figures, 3 tables; Reviews of Modern Physics, accepte

Serum Amyloid A Binds to Gibrin(ogen), Promoting Fibrin Amyloid Formation

Complex associations exist between inflammation and thrombosis, with the inflammatory state tending to promote coagulation. Fibrinogen, an acute phase protein, has been shown to interact with the amyloidogenic ß-amyloid protein of Alzheimer’s disease. However, little is known about the association between fibrinogen and serum amyloid A (SAA), a highly fibrillogenic protein that is one of the most dramatically changing acute phase reactants in the circulation. To study the role of SAA in coagulation and thrombosis, in vitro experiments were performed where purified human SAA, in concentrations resembling a modest acute phase response, was added to platelet-poor plasma (PPP) and whole blood (WB), as well as purified and fluorescently labelled fibrinogen. Results from thromboelastography (TEG) suggest that SAA causes atypical coagulation with a fibrin(ogen)-mediated increase in coagulation, but a decreased platelet/fibrin(ogen) interaction. In WB scanning electron microscopy analysis, SAA mediated red blood cell (RBC) agglutination, platelet activation and clumping, but not platelet spreading. Following clot formation in PPP, the presence of SAA increased amyloid formation of fibrin(ogen) as determined both with auto-fluorescence and with fluorogenic amyloid markers, under confocal microcopy. SAA also binds to fibrinogen, as determined with a fluorescent-labelled SAA antibody and correlative light electron microscopy (CLEM). The data presented here indicate that SAA can affect coagulation by inducing amyloid formation in fibrin(ogen), as well as by propelling platelets to a more prothrombotic state. The discovery of these multiple and complex effects of SAA on coagulation invite further mechanistic analyses

Spectroscopic factors for bound s-wave states derived from neutron scattering lengths

A simple and model-independent method is described to derive neutron single-particle spectroscopic factors of bound s-wave states in $^{A+1}Z = ^{A}Z \otimes n$ nuclei from neutron scattering lengths. Spectroscopic factors for the nuclei ^{13}C, ^{14}C, ^{16}N, ^{17}O, ^{19}O, ^{23}Ne, ^{37}Ar, and ^{41}Ar are compared to results derived from transfer experiments using the well-known DWBA analysis and to shell model calculations. The scattering length of ^{14}C is calculated from the ^{15}C_{g.s.} spectroscopic factor.Comment: 9 pages (uses revtex), no figures, accepted for publication in PRC, uuencoded tex-files and postscript-files available at ftp://is1.kph.tuwien.ac.at/pub/ohu/Thermal.u

Individual Actions as Community Informative Resources. A Collective Informative Systems Approach

This paper conceives communities (in this case, partnerships) as being able to become collective informative repositories of individual and collective actions that may better-inform their members. This paper presents one approach for studying if a community has become such an informative repository. The approach used here consists of introducing a formal language (Viable Systems Modelling, VSM) into one of the community nodes (a participant) and tracing if its use is seen in another node (another participant) - indicating the presence of a process of diffusion. This research design has been tested in a crime-reduction partnership in the UK. One of its members was asked to engage in the design and testing of this approach as a co-researcher. As a result, a questionnaire to map communication and control devices inside an organization was jointly developed. In keeping with VSM principles, the questionnaire encouraged participants to reflect on attenuation and amplification processes within their communications channels. To test the quality of the outcomes of this approach, members from another crime-reduction partnership were also invited to answer the survey; this was to confirm that VSM notions were not evident for those outside the development and testing of the questionnaire. The questionnaire indicated also its capability to make visible communication and organizational processes within collectives and its potential to stimulate self-organization, for those individuals who became familiar with VSM. Furthermore, this approach provided the authors with the capability to study information flows inside the two collectives, and contributed to an understanding of these flows as a model for building and maintaining a Community Informative System

A study of the proton spectra following the capture of K−K^- in 6^6Li and 12^{12}C with FINUDA

Momenta spectra of protons emitted following the capture of $K^-$ in $^6$Li and $^{12}$C have been measured with 1% resolution. The $^{12}$C spectrum is smooth whereas for $^6$Li a well defined peak appears at about 500 MeV/$c$. The first observation of a structure in this region was identified as a strange tribaryon or, possibly, a $\bar K$-nuclear state. The peak is correlated with a $\pi^-$ coming from $\Sigma^-$ decay in flight, selected by setting momenta larger than 275 MeV/$c$. The $\Sigma^-$ could be produced, together with a 500 MeV/$c$ proton, by the capture of a $K^-$ in a deuteron-cluster substructure of the $^6$Li nucleus. The capture rate for such a reaction is (1.62\pm 0.23_{stat} ^{+0.71}_{-0.44}(sys))%/K^-_{stop}, in agreement with the existing observations on $^4$He targets and with the hypothesis that the $^6$Li nucleus can be interpreted as a $(d+\alpha)$ cluster.Comment: 21 pages, 10 figures. Accepted for publication in NP