2,154 research outputs found

    Henneguya sp. in yellowfin goby Acanthogobius flavimanus from the San Francisco Estuary.

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    Myxozoan spores were observed in yellowfin goby Acanthogobius flavimanus collected from Suisun Marsh, San Francisco Estuary (SFE). Although histopathological changes associated with the parasite were not observed, the spores formed plasmodia that partially blocked the gastric and intestinal mucosa and gut lumen and may affect the perfomance and survival of the yellowfin goby. Morphological features of the spores resembled Henneguya sp. and molecular analysis of the 18S ribosomal DNA (Domain III) confirmed close similarity to H. rhinogobii and H. pseudorhinogobii isolated from the Japanese freshwater goby. The yellowfin goby myxozoan however, is likely an undescribed species based on phylogenetic analysis and morphologic features. Detailed description of vegetative and spore stages are currently lacking for proposal to a new species of Henneguya. A specific PCR test was developed, which confirmed a 100% prevalence of the parasite among randomly collected gobies in group 1 (N = 30) and group 2 (N = 15) at termination of the study at one month in captivity. The myxozoan was also detected from 18 gobies (12%) that died in the first group within two weeks in captivity. Apparently healthy gobies that served as controls did not reveal the presence of the myxozoan by PCR. This study documents the occurrence of a potentially new species of myxozoan in the yellowfin goby and underscores the detection of a parasitic infection in an introduced fish in the SFE. Although the pathogenesis of the myxozoan was not assessed and the prevalence as reported here is restricted to a comparatively small collection site in Suisun slough, the reemergence, identification, and ecological relevance of the parasite on goby populations in the SFE may be investigated in the future using the specific diagnostic tool developed in this study

    Quaternary pulse position modulation electronics for free-space laser communications

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    The development of a high data-rate communications electronic subsystem for future application in free-space, direct-detection laser communications is described. The dual channel subsystem uses quaternary pulse position modulation (QPPM) and operates at a throughput of 650 megabits per second. Transmitting functions described include source data multiplexing, channel data multiplexing, and QPPM symbol encoding. Implementation of a prototype version in discrete gallium arsenide logic, radiofrequency components, and microstrip circuitry is presented

    A Fluctuation Analysis of the Bolocam 1.1mm Lockman Hole Survey

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    We perform a fluctuation analysis of the 1.1mm Bolocam Lockman Hole Survey, which covers 324 square arcmin to a very uniform point source-filtered RMS noise level of 1.4 mJy/beam. The fluctuation analysis has the significant advantage of utilizing all of the available data. We constrain the number counts in the 1-10 mJy range, and derive significantly tighter constraints than in previous work: the power-law index is 2.7 (+0.18, -0.15), while the amplitude is equal to 1595 (+85,-238) sources per mJy per square degree, or N(>1 mJy) = 940 (+50,-140) sources/square degree (95% confidence). Our results agree extremely well with those derived from the extracted source number counts by Laurent et al (2005). Our derived normalization is about 2.5 times smaller than determined by MAMBO at 1.2mm by Greve et al (2004). However, the uncertainty in the normalization for both data sets is dominated by the systematic (i.e., absolute flux calibration) rather than statistical errors; within these uncertainties, our results are in agreement. We estimate that about 7% of the 1.1mm background has been resolved at 1 mJy.Comment: To appear in the Astrophysical Journal; 22 pages, 9 figure

    The Spectrum projection package: improvements in estimating mortality, ART needs, PMTCT impact and uncertainty bounds

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    BACKGROUND: The approach to national and global estimates of HIV/AIDS used by UNAIDS starts with estimates of adult HIV prevalence prepared from surveillance data using either the Estimation and Projection Package (EPP) or the Workbook. Time trends of prevalence are transferred to Spectrum to estimate the consequences of the HIV/AIDS epidemic, including the number of people living with HIV, new infections, AIDS deaths, AIDS orphans, treatment needs and the impact of treatment on survival. METHODS: The UNAIDS Reference Group on Estimates, Modelling and Projections regularly reviews new data and information needs and recommends updates to the methodology and assumptions used in Spectrum. The latest update to Spectrum was used in the 2007 round of global estimates. RESULTS: Several new features have been added to Spectrum in the past two years. The structure of the population was reorganised to track populations by HIV status and treatment status. Mortality estimates were improved by the adoption of new approaches to estimating non-AIDS mortality by single age, and the use of new information on survival with HIV in non-treated cohorts and on the survival of patients on antiretroviral treatment (ART). A more detailed treatment of mother-to-child transmission of HIV now provides more prophylaxis and infant feeding options. New procedures were implemented to estimate the uncertainty around each of the key outputs. CONCLUSIONS: The latest update to the Spectrum program is intended to incorporate the latest research findings and provide new outputs needed by national and international planners

    The Spectrum projection package: improvements in estimating incidence by age and sex, mother-to-child transmission, HIV progression in children and double orphans

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    BACKGROUND: The Spectrum program is used to estimate key HIV indicators from the trends in incidence and prevalence estimated by the Estimation and Projection Package or the Workbook. These indicators include the number of people living with HIV, new infections, AIDS deaths, AIDS orphans, the number of adults and children needing treatment, the need for prevention of mother-to-child transmission and the impact of antiretroviral treatment on survival. The UNAIDS Reference Group on Estimates, Models and Projections regularly reviews new data and information needs, and recommends updates to the methodology and assumptions used in Spectrum. METHODS: The latest update to Spectrum was used in the 2009 round of global estimates. This update contains new procedures for estimating: the age and sex distribution of adult incidence, new child infections occurring around delivery or through breastfeeding, the survival of children by timing of infection and the number of double orphans

    What is required to end the AIDS epidemic as a public health threat by 2030? The cost and impact of the fast-track approach

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    In 2011 a new Investment Framework was proposed that described how the scale-up of key HIV interventions could dramatically reduce new HIV infections and AIDS-related deaths in low and middle income countries by 2015. This framework included ambitious coverage goals for prevention and treatment services for 2015, resulting in a reduction of new HIV infections by more than half, in line with the goals of the declaration of the UN High Level Meeting in June 2011. However, the approach suggested a leveling in the number of new infections at about 1 million annually-far from the UNAIDS goal of ending AIDS by 2030. In response, UNAIDS has developed the Fast-Track approach that is intended to provide a roadmap to the actions required to achieve this goal. The Fast-Track approach is predicated on a rapid scale-up of focused, effective prevention and treatment services over the next 5 years and then maintaining a high level of programme implementation until 2030. Fast-Track aims to reduce new infections and AIDS-related deaths by 90% from 2010 to 2030 and proposes a set of biomedical, behavioral and enabling intervention targets for 2020 and 2030 to achieve that goal, including the rapid scale-up initiative for antiretroviral treatment known as 90-90-90. Compared to a counterfactual scenario of constant coverage for all services at early-2015 levels, the Fast-Track approach would avert 18 million HIV infections and 11 million deaths from 2016 to 2030 globally. This paper describes the analysis that produced these targets and the estimated resources needed to achieve them in low- and middle-income countries. It indicates that it is possible to achieve these goals with a significant push to achieve rapid scale-up of key interventions between now and 2020. The annual resources required from all sources would rise to US7.4Bninlowincomecountries,US7.4Bn in low-income countries, US8.2Bn in lower middle-income countries and US$10.5Bn in upper-middle-income-countries by 2020 before declining approximately 9% by 2030

    Irradiation of the secondary star in X-ray Nova Scorpii 1994 (=GRO J1655--40)

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    We have obtained intermediate resolution optical spectra of the black-hole candidate Nova Sco 1994 in June 1996, when the source was in an X-ray/optical active state (R~15.05). We measure the radial velocity curve of the secondary star and obtain a semi-amplitude of 279+/-10 km/s; a value which is 30 per cent larger than the value obtained when the source is in quiescence. Our large value for K_2 is consistent with 60 +9,-7 per cent of the secondary star's surface being heated; compared to 35 per cent, which is what one would expect if only the inner face of the secondary star were irradiated. Effects such as irradiation-induced flows on the secondary star may be important in explaining the observed large value for K_2.Comment: 5 pages, 2 figures, accepted by MNRA

    The Mental and Physical Health of Mothers of Children with Special Health Care Needs in the United States

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    OBJECTIVE: To determine the prevalence of poor mental and physical health among mothers of children with special health care needs (CSHCN) and to determine the association between maternal health and the child\u27s number of special health care needs (SHCN) and severity of ability limitation. METHODS: We used the combined 2016-2018 National Survey of Children\u27s Health Dataset of 102,341 children ages 0-17 including 23,280 CSHCN. We used regression models to examine the associations of a child\u27s number of SHCN and ability limitations with maternal health. RESULTS: Twice as many mothers of CSHCN had poor mental and physical health compared to non-CSHCN (mental 10.3% vs. 4.0%, p \u3c .001; physical 11.9% vs 5.0%, p \u3c .001). In regression models, increased number of SHCN and severity of activity limitations were associated with significantly increased odds of poor maternal health. CONCLUSIONS FOR PRACTICE: Mothers of CSHCN have worse health compared to mothers of non-CSHCN, especially those who experience social disadvantage and those with children with complex SHCN or severe ability limitations. Interventions to improve the health of these particularly vulnerable caregivers of CSHCN are warranted

    Effects of Impurity Content on the Sintering Characteristics of Plasma-Sprayed Zirconia

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    Yttria-stabilized zirconia powders, containing different levels of SiO2 and Al2O3, have been plasma sprayed onto metallic substrates. The coatings were detached from their substrates and a dilatometer was used to monitor the dimensional changes they exhibited during prolonged heat treatments. It was found that specimens containing higher levels of silica and alumina exhibited higher rates of linear contraction, in both in-plane and through-thickness directions. The in-plane stiffness and the through-thickness thermal conductivity were also measured after different heat treatments and these were found to increase at a greater rate for specimens with higher impurity (silica and alumina) levels. Changes in the pore architecture during heat treatments were studied using Mercury Intrusion Porosimetry (MIP). Fine scale porosity (<_50 nm) was found to be sharply reduced even by relatively short heat treatments. This is correlated with improvements in inter-splat bonding and partial healing of intra-splat microcracks, which are responsible for the observed changes in stiffness and conductivity, as well as the dimensional changes
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