127 research outputs found

    Time extended production of neutrons during a solar flare

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    The most energetic neutral emissions expected from solar flares are gamma rays (10 MeV) from relativistic primary and secondary electron bremsstrahlung,from approx 0 meson decay, and from neutrons ( 50 MeV). Bremsstrahlung photon energies extend to that of the highest energy electron present, but the shape of the pi sup 0 gamma ray spectrum, peaking at 69 MeV, does not depend strongly on the proton spectrum above threshold, which is approx. 292 MeV for meson production on protons. The highest energy neutrons observed indicate directly the highest energy ions which interact at the Sun, and the presence or absence of anergy cutoff in the acceleration process. The high-energy proton spectrum shape can be determined from the neutron spectrum

    Assessment of Trachoma in Cambodia: Trachoma Is Not a Public Health Problem.

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    PURPOSE: To determine whether trachoma is a public health problem requiring intervention in Cambodia. METHODS: Based on historical evidence and reports, 14 evaluation units (EUs) in Cambodia, judged to be most likely to harbor trachoma, were selected. The Global Trachoma Mapping Project methodology was used to carry out rigorous surveys to determine the prevalence of trachomatous inflammation-follicular (TF) and trichiasis in each EU. RESULTS: The EU-level prevalence of TF among 25,801 1-9-year-old children examined ranged from 0% to 0.2%. Among the 24,502 adults aged 15+ years examined, trichiasis was found in 59 people. Age- and sex-adjusted prevalences of trichiasis in all ages in the EUs studied ranged from 0% to 0.14%; five EUs had a prevalence of trichiasis ≥0.1%. CONCLUSIONS: There appears to be no need nor justification at this time for implementing public health measures to control trachoma in Cambodia

    Completion of Baseline Trachoma Mapping in Malawi: Results of Eight Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project.

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    PURPOSE: Following a first phase of trachoma mapping in Malawi with the Global Trachoma Mapping Project, we identified and mapped trachoma districts previously suspected to be non-endemic, although adjacent to districts with estimated trachoma prevalences indicating a public health problem. METHODS: We conducted population-based surveys in eight evaluation units (EUs) comprising eight districts in Malawi (total population 3,230,272). A 2-stage cluster random sampling design allowed us to select 30 households from each of 30 clusters per EU; all residents aged 1 year and older in selected households were examined for evidence of trachomatous inflammation-follicular (TF) and trachomatous trichiasis (TT). RESULTS: None of the eight EUs had a TF prevalence in 1-9-year-olds ≥10%, one district (Dedza) had a TF prevalence between 5.0% and 9.9%, and only one district (Karonga) had a trichiasis prevalence in adults ≥0.2%. CONCLUSION: The prevalence of TF and TT in six of eight EUs surveyed was consistent with an original categorization of trachoma being unlikely to be a public health problem. In the absence of formal surveys, health management information system data and other locally available information about trachoma is likely to be useful in predicting areas where public health interventions against trachoma are required

    Real-time RMS active damping augmentation: Heavy and very light payload evaluations

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    Controls-Structures Integration Technology has been applied to the Space Shuttle Remote Manipulator System (RMS) to improve on-orbit performance. The objective was to actively damp undesired oscillatory motions of the RMS following routine payload maneuvering and Shuttle attitude control thruster firings. Simulation of active damping was conducted in the real-time, man-in-the-loop Systems Engineering Simulator at NASA's Johnson Space Center. The simulator was used to obtain qualitative and quantitative data on active damping performance from astronaut operators. Using a simulated three-axis accelerometer mounted on the RMS, 'sensed' vibration motions were used to generate joint motor commands that reduced the unwanted oscillations. Active damping of the RMS with heavy and light attached payloads was demonstrated in this study. Five astronaut operators examined the performance of active damping following operator commanded RMS maneuvers and Shuttle thruster firings. Noticeable improvements in the damping response of the RMS with the heavy, Hubble Space Telescope payload and the very light, astronaut in Manipulator Foot Restraint payload were observed. The potential of active damping to aid in precisely maneuvering payloads was deemed significant

    Trachoma and Yaws: Common Ground?

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    Trachoma is an important cause of blindness. The causative organism is an intracellular bacterium, Chlamydia trachomatis, which is susceptible to single-dose azithromycin. A World Health Organization (WHO)-led program aims to eliminate trachoma as a public health problem globally by 2020. Yaws is a cause of skin, bone, and cartilage disease. The causative organism is a spirochaete bacterium, Treponema pallidum ssp. pertenue, which is susceptible to single-dose azithromycin. A WHO-led program aims to eradicate yaws globally by 2020

    Fecopneumothorax and colopleural fistula – uncommon complications of Crohn's disease

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    BACKGROUND: Colopleural fistula and fecopneumothorax are very rare complications of Crohn's disease. Fistula formation is frequent in Crohn's disease and occurs in approximately 33% of patients. On the other hand, fistulous communication between the pleural cavity and adjacent organs below the diaphragm is extremely rare. CASE PRESENTATION: We describe the case of 27 year-old female with colopleural fistula as a complication of Crohn's disease. The diagnosis was established with clinical exam, barium enema, chest X-ray, abdominal and chest CT exam. The treatment was surgical. CONCLUSION: Colopleural fistula and fecopneumothorax are rare but life treating complications of Crohn's disease. Surgical treatment is mandatory as soon as the diagnosis is established

    Prevalence of Trachoma in Gambella Region, Ethiopia: Results of Three Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project.

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    PURPOSE: In Ethiopia, trachoma is a major public health problem, accounting for 11.5% of all cases of blindness. In Gambella, one of the country's most remote regions, the 2005-2006 National Survey of Blindness, Low Vision and Trachoma estimated a region-level prevalence of active trachoma of 19.1% in those aged 1-9 years. Detailed district or sub-regional level estimates are required to implement interventions. METHODS: Population-based prevalence surveys were carried out following a 2-stage cluster random sampling methodology and Global Trachoma Mapping Project protocols. As the 13 districts (woredas) in Gambella had relatively small populations, they were grouped together to form three evaluation units (EUs) of about 100,000 persons each, and all subsequent survey planning and sampling was carried out at EU-level. RESULTS: Altogether, 558 cases of TF (17.2%) were identified in 3238 children aged 1-9 years across the three EUs. The adjusted TF prevalences in 1-9-year-olds for the three EUs were 11.5%, 12.5% and 19.3%; 14.4% for Gambella overall. A total of 142 cases of trichiasis (3.8%) were identified among 3781 adults aged 15 years or older, with age- and sex-adjusted EU-level trichiasis prevalences in adults being 0.8%, 1.3% and 2.4%; 1.5% overall. CONCLUSION: The high prevalences of TF and trichiasis throughout Gambella indicate a need for rapid scaling up of the World Health Organization SAFE strategy (surgery, antibiotics, facial cleanliness, and environmental improvement) to help meet the 2020 target of global elimination of trachoma as a public health problem

    Prevalence of Trachoma in Benishangul Gumuz Region, Ethiopia: Results of Seven Population-Based Surveys from the Global Trachoma Mapping Project.

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    PURPOSE: Trachoma is a major cause of blindness in Ethiopia, and targeted for elimination as a public health problem by the year 2020. Prevalence data are needed to plan interventions. We set out to estimate the prevalence of trachoma in each evaluation unit of grouped districts ("woredas") in Benishangul Gumuz region, Ethiopia. METHODS: We conducted seven cross-sectional community-based surveys, covering 20 woredas, between December 2013 and January 2014, as part of the Global Trachoma Mapping Project (GTMP). The standardized GTMP training package and methodologies were used. RESULTS: A total of 5828 households and 21,919 individuals were enumerated in the surveys. 19,583 people (89.3%) were present when survey teams visited. A total of 19,530 (99.7%) consented to examination, 11,063 (56.6%) of whom were female. The region-wide age- and sex-adjusted trichiasis prevalence in adults aged ≥15 years was 1.3%. Two evaluation units covering four woredas (Pawe, Mandura, Bulen and Dibate) with a combined rural population of 166,959 require implementation of the A, F and E components of the SAFE strategy (surgery, antibiotics, facial cleanliness and environmental improvement) for at least three years before re-survey, and intervention planning should begin for these woredas as soon as possible. CONCLUSION: Both active trachoma and trichiasis are public health problems in Benishangul Gumuz, which needs implementation of the full SAFE strategy

    Trachoma Mapping in Gombe State, Nigeria: Results of 11 Local Government Area Surveys.

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    PURPOSE: To determine the need or otherwise for establishment of a trachoma elimination program in Gombe State, Nigeria, by estimating the population-based prevalence of trachoma in each Local Government Area (LGA) of Gombe. METHODS: Using a multi-stage, systematic, random, and quasi-random sampling approach and Global Trachoma Mapping Project support, we selected 25 clusters in each LGA. In each cluster, we selected 25 households and all consenting residents aged 1 year and older were examined for trachomatous inflammation-follicular (TF) and trichiasis, using the World Health Organization simplified grading scheme. RESULTS: No LGA in Gombe State had a TF prevalence ≥5% in 1-9-year-olds. All LGAs had trichiasis prevalences above the elimination threshold and should be targeted for community-based delivery of trichiasis surgery. Only three LGAs had household-level improved wash water access of greater than 80%. Access to improved sanitation facilities was also poor as household access to improved sanitation facilities was above 80% in only one LGA. CONCLUSION: A trachoma program focused on delivery of trichiasis surgery is required in Gombe. Improvements in water and sanitation, through engagement with other sectors, are necessary
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