The Detection, Characterization and Tracking of Recent Aleutian Island Volcanic Ash Plumes and the Assessment of Their Impact on Aviation

The Aleutian Islands of Alaska are home to a number of major volcanoes which periodically present a significant hazard to aviation. During summer of 2008, the Okmok and Kasatochi volcanoes experienced moderate eruptive events. These were followed a dramatic, major eruption of Mount Redoubt in late March 2009. The Redoubt case is extensively covered in this paper. Volcanic ash and SO2 from each of these eruptions dispersed throughout the atmosphere. This created the potential for major problems for air traffic near the ash dispersions and at significant distances downwind. The NASA Applied Sciences Weather Program implements a wide variety of research projects to develop volcanic ash detection, characterization and tracking applications for NASA Earth Observing System and NOAA GOES and POES satellites. Chemistry applications using NASA AURA satellite Ozone Monitoring System (OMI) retrievals produced SO2 measurements to trace the dispersion of volcanic aerosol. This work was complimented by advanced multi-channel imager applications for the discrimination and height assignment of volcanic ash using NASA MODIS and NOAA GOES and POES imager data. Instruments similar to MODIS and OMI are scheduled for operational deployment on NPOESS. In addition, the NASA Calipso satellite provided highly accurate measurements of aerosol height and dispersion for the calibration and validation of these algorithms and for corroborative research studies. All of this work shortens the lead time for transition to operations and ensures that research satellite data and applications are operationally relevant and utilized quickly after the deployment of operational satellite systems. Introductio

Human herpes virus 8 replication during disseminated tuberculosis in a man with human immunodeficiency virus: a case report

INTRODUCTION: Human herpes virus 8 (HHV-8) is mainly responsible for the development of Kaposi's sarcoma and multicentric Castleman's disease in immunocompromised patients with untreated human immunodeficiency virus. Positive viral loads have been described in cases of Kaposi's sarcoma and multicentric Castleman's disease, with higher values found in the latter. We describe the case of a patient with HIV in whom a high level of HHV-8 replication was detected and who contracted an opportunistic disease other than multicentric Castleman's disease or Kaposi's sarcoma. CASE PRESENTATION: A 25-year-old man of West African origin with HIV complained of asthenia, weight loss, fever, and abdominal pain. Physical examination revealed that the patient had adenopathies and hepatosplenomegaly, but no skin or mucosal lesions were seen. Our first presumptive diagnosis was disseminated tuberculosis. However, since the cultures (sputum, bronchoalveolar lavage, blood, urine and lymph node biopsies) for mycobacteria were negative, the diagnosis was expanded to include multicentric Castleman's disease which was supported by high HHV-8 viral loads in the patient's blood: 196,000 copies/ml in whole blood, 39,400 copies/ml in plasma and 260 copies/10E5 in peripheral blood mononuclear cells. However, the histology and positive polymerase chain reaction assay for Mycobacterium tuberculosis complex of a second lymph node biopsy enabled us to conclude that the patient had disseminated tuberculosis and we started the patient on antituberculosis treatment. We analyzed the HHV-8 deoxyribonucleic acid in two other plasma samples (one from six months earlier and the other was 10 days after the positive test) and both yielded negative results. A search for latent and lytic HHV-8 antibodies confirmed that the patient was seropositive for HHV-8 before this episode. CONCLUSION: We describe the case of a patient with HIV who tested positive for asymptomatic HHV-8 replication during an opportunistic disease suggestive of multicentric Castleman's disease. The initial analysis was nullified by the diagnosis of a disease that was unrelated to HHV-8. This case report underlines the need to clarify the full clinical meaning and implication of a positive HHV-8 viral load in patients with AIDS. The diagnosis of multicentric Castleman's disease needs to be studied further to determine its sensitivity and specificity. Finally, when faced with the dilemma of urgently starting chemotherapy on a patient whose condition is deteriorating and whose clinical presentation suggests multicentric Castleman's disease, high HHV-8 viral loads should be interpreted with caution and histological analysis of lymph nodes or liver biopsies should be obtained first

Use of ring-expanded diamino- and diamidocarbene ligands in copper catalyzed azide-alkyne "click" reactions

The two-coordinate ring-expanded N-heterocyclic carbene copper­(I) complexes [Cu­(RE-NHC)₂]⁺ (RE-NHC = 6-Mes, 7-<i>o</i>-Tol, 7-Mes) have been prepared and shown to be effective catalysts under neat conditions for the 1,3-dipolar cycloaddition of alkynes and azides. In contrast, the cationic diamidocarbene analogue [Cu­(6-MesDAC)₂]⁺ and the neutral species [(6-MesDAC)­CuCl]₂ and [(6-MesDAC)₂(CuCl)₃] show good activity when the catalysis is performed on water

Novel Mouse Xenograft Models Reveal a Critical Role of CD4+ T Cells in the Proliferation of EBV-Infected T and NK Cells

Epstein-Barr virus (EBV), a ubiquitous B-lymphotropic herpesvirus, ectopically infects T or NK cells to cause severe diseases of unknown pathogenesis, including chronic active EBV infection (CAEBV) and EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH). We developed xenograft models of CAEBV and EBV-HLH by transplanting patients' PBMC to immunodeficient mice of the NOD/Shi-scid/IL-2Rγnull strain. In these models, EBV-infected T, NK, or B cells proliferated systemically and reproduced histological characteristics of the two diseases. Analysis of the TCR repertoire expression revealed that identical predominant EBV-infected T-cell clones proliferated in patients and corresponding mice transplanted with their PBMC. Expression of the EBV nuclear antigen 1 (EBNA1), the latent membrane protein 1 (LMP1), and LMP2, but not EBNA2, in the engrafted cells is consistent with the latency II program of EBV gene expression known in CAEBV. High levels of human cytokines, including IL-8, IFN-γ, and RANTES, were detected in the peripheral blood of the model mice, mirroring hypercytokinemia characteristic to both CAEBV and EBV-HLH. Transplantation of individual immunophenotypic subsets isolated from patients' PBMC as well as that of various combinations of these subsets revealed a critical role of CD4+ T cells in the engraftment of EBV-infected T and NK cells. In accordance with this finding, in vivo depletion of CD4+ T cells by the administration of the OKT4 antibody following transplantation of PBMC prevented the engraftment of EBV-infected T and NK cells. This is the first report of animal models of CAEBV and EBV-HLH that are expected to be useful tools in the development of novel therapeutic strategies for the treatment of the diseases

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Tuning the Electronic Properties of Carbenes: A Systematic Comparison of Neighboring Amino versus Amido Groups

A related series of six-membered carbenes featuring adjoining amino and/or amido groups (i.e, a diaminocarbene, a monoamido-aminocarbene (3), and a a diamidocarbene (6)) were systematically compared using crystallographic, spectroscopic, electro-chemical, and density functional theory methods. The solid-state structure of 3 was found to exhibit inequivalent nitrogen carbon bond lengths (C-carbene-N-amide= 1.395(4) angstrom vs C-carbene-N-amine = 1.323(4) angstrom). Moreover, the C-carbene-N-amide distance was longer than that measured in the solid-state structure of 6 (1.371(3) angstrom), while the C-carbene-N-amine distance was similar to that measured in the solid-state structure of a cyclic alkyl-aminocarbene (1.315(3) angstrom). Iridium complexes of the aforementioned carbenes were also evaluated, and the collected data revealed that the introduction of carbonyl groups to the carbene-containing scaffold had a nearly linear, additive effect on the E-1/2 potential of the carbene-ligated iridium I/II redox couple (+165 mV per carbonyl added) as well as the Tolman electronic parameter value of the corresponding carbene-Ir(CO)(2)Cl complex (ca. 7 cm(-1) per carbonyl added). Beyond attenuated ligand donicity, the introduction of carbonyl groups was found to broaden the chemical reactivity: unlike prototypical N-heterocyclic carbenes, including diaminocarbenes, the monoamido-aminocarbene was found to couple to isonitriles to form the respective ketenimines

Evaluation of portable x-ray fluorescence for gypsum quantification in soils

The use of field portable X-ray fluorescence (XRF) spectrometry as a quantification tool for gypsum content in soils of West Texas and southern New Mexico, USA, was evaluated. Six sites were evaluated with gypsum contents ranging from less than 10% to greater than 90%. Samples collected from each site were scanned in the field using XRF and then transported to the laboratory for additional XRF scanning. Variables that might affect XRF scanning results, such as scanning time, particle size, moisture content, and so on, were evaluated. Both gypsum (CaSO4 • 2H2O) and calcite (CaCO 3) were quantified using standard laboratory techniques. Three data sets were compared: (1) soil characterization data, obtained from the National Soil Survey Laboratory Research Database in Lincoln, NE; (2) quantitative X-ray diffraction; and (3) portable XRF (PXRF). The best correlation of gypsum XRF data (via Ca quantification minus calcite content) and laboratory data was between PXRF and quantitative X-ray diffraction (R = 0.96). On average, PXRF provided results within 6% of soil characterization data, the current laboratory standard for gypsum quantification. Field PXRF shows considerable promise as a rapid, quantifiable measure of gypsum in soils. © 2009 by Lippincott Williams & Wilkins, Inc.Peer Reviewe