29 research outputs found

    Laser induced fluorescence characterization of ions emitted from hollow cathodes

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76900/1/AIAA-1999-2862-539.pd

    Near-field investigation of ions emitted from a hollow cathode assembly operating at low-power

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76514/1/AIAA-1998-3658-652.pd

    Risk factors for human brucellosis in northern Tanzania

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    Little is known about the epidemiology of human brucellosis in sub-Saharan Africa. This hampers prevention and control efforts at the individual and population levels. To evaluate risk factors for brucellosis in northern Tanzania, we conducted a study of patients presenting with fever to two hospitals in Moshi, Tanzania. Serum taken at enrollment and at 4–6 week follow-up was tested by Brucella microagglutination test. Among participants with a clinically compatible illness, confirmed brucellosis cases were defined as having a ≥ 4-fold rise in agglutination titer between paired sera or a blood culture positive for Brucella spp., and probable brucellosis cases were defined as having a single reciprocal titer ≥ 160. Controls had reciprocal titers < 20 in paired sera. We collected demographic and clinical information and administered a risk factor questionnaire. Of 562 participants in the analysis, 50 (8.9%) had confirmed or probable brucellosis. Multivariable analysis showed that risk factors for brucellosis included assisting goat or sheep births (Odds ratio [OR] 5.9, 95% confidence interval [CI] 1.4, 24.6) and having contact with cattle (OR 1.2, 95% CI 1.0, 1.4). Consuming boiled or pasteurized dairy products was protective against brucellosis (OR 0.12, 95% CI 0.02, 0.93). No participants received a clinical diagnosis of brucellosis from their healthcare providers. The under-recognition of brucellosis by healthcare workers could be addressed with clinician education and better access to brucellosis diagnostic tests. Interventions focused on protecting livestock keepers, especially those who assist goat or sheep births, are needed

    Risk factors for human acute leptospirosis in northern Tanzania

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    Introduction: Leptospirosis is a major cause of febrile illness in Africa but little is known about risk factors for human infection. We conducted a cross-sectional study to investigate risk factors for acute leptospirosis and Leptospira seropositivity among patients with fever attending referral hospitals in northern Tanzania. Methods: We enrolled patients with fever from two referral hospitals in Moshi, Tanzania, 2012–2014, and performed Leptospira microscopic agglutination testing on acute and convalescent serum. Cases of acute leptospirosis were participants with a four-fold rise in antibody titers, or a single reciprocal titer ≥800. Seropositive participants required a single titer ≥100, and controls had titers <100 in both acute and convalescent samples. We administered a questionnaire to assess risk behaviors over the preceding 30 days. We created cumulative scales of exposure to livestock urine, rodents, and surface water, and calculated odds ratios (OR) for individual behaviors and for cumulative exposure variables. Results: We identified 24 acute cases, 252 seropositive participants, and 592 controls. Rice farming (OR 14.6), cleaning cattle waste (OR 4.3), feeding cattle (OR 3.9), farm work (OR 3.3), and an increasing cattle urine exposure score (OR 1.2 per point) were associated with acute leptospirosis. Conclusions: In our population, exposure to cattle and rice farming were risk factors for acute leptospirosis. Although further data is needed, these results suggest that cattle may be an important source of human leptospirosis. Further investigation is needed to explore the potential for control of livestock Leptospira infection to reduce human disease

    Oxidative stability of direct-expanded chickpea–sorghum snacks

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    In contrast to other pulses, chickpea has a relatively high fat content (3%–10%). This study was designed to investigate direct-expanded chickpea–sorghum extruded snacks (50:50, 60:40, and 70:30 chickpea:sorghum, w/w) with respect to: their oxidative stability and sensory properties during accelerated (55°C) and room temperature (25°C) storage; correlations between chemical markers (peroxide value and p-anisidine value) and sensory data during accelerated storage; and the shelf-life of snacks extruded at the optimal expansion point as determined by a rotatable central composite design. Peroxide values and p-anisidine values were in the range of 0–2.5 mEq/Kg and 5–30, respectively, for both accelerated and room temperature storage, and increased during storage (p < .05). 70:30 and 60:40 (w/w) chickpea–sorghum snacks had higher peroxide and p-anisidine values compared to the 50:50 snack during storage at either temperature (p < .05). Rancid aroma and off-flavor of 60:40 and 70:30 chickpea–sorghum snacks (slightly intense = 6) also were higher than that of the 50:50 snack (moderately weak = 3) (p < .05). Significant correlations (p < .05) were found between chemical markers and sensory attributes (p < .05). The study illustrated that shelf-life decreased as the percentage of chickpea in the blend increased. Therefore, in terms of shelf-life, a 50:50 chickpea–sorghum blend is preferable

    Near-field investigation of ions emitted from a hollow cathode assembly operating at low-power

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    The properties and enzymic activity of endoglucanases (EC 3.2.1.4) of the fungus Trichoderma reesei were studied by means of immunological methods and by using polyglycosidic substrates. Endoglucanases exist in the culture liquid as a series of immunologically related components. The most active endoglucanase component has an Mr of 43 000 and pI value of 4.0. The most abundant components have a value of pI about 5.0, an Mr of 56 000-67 000 and specific activity only one-fifth of that of the pI-4.0 component. During purification and storage the endoglucanases are spontaneously modified; the relative proportion of components having greater Mr values, more alkaline pI values and lower specific activities is increased. The hexose content of the endoglucanase components is 2-7%. Endoglucanases hydrolyse soluble beta-1,4 glycans. The enzymes described here differ from endoglucanase preparations described previously in not showing activity towards insoluble substrates. The role of endoglucanases in wood hydrolysis is consequently limited to the stage where wood constituents are already in soluble form

    Fast-timing measurements in neutron-rich odd-mass zirconium isotopes using LaBr3:Ce detectors coupled with Gammasphere

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    A fast-timing experiment was performed at the Argonne National Laboratory to measure the lifetimes of the lowest lying states of nuclei belonging to the deformed regions around mass number A 110 and A 150. These regions were populated via spontaneous fission of 252Cf and the gamma radiation following the decay of excited states in the fission fragments was measured using 51 Gammasphere detectors coupled with 25 LaBr3:Ce detectors. A brief description of the acquisition system and some preliminary results from the fast-timing analysis of the fission fragment 100Zr are presented. The lifetime value of Ï„ = 840(65) ps was found for the 2+ state in 100Zr consistent within one standard deviation of the adopted value with 791 +26 -35ps. This is associated with a quadrupole deformation parameter of 0.36(2) which is within one standard deviation of the literature value of 0.3556+82 -57.UK authors acknowledge the support of the Science and Technology Facilities Council (STFC)
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