588 research outputs found

    The EZIE Way to Measure the Ionospheric Electrojets with a Three-CubeSat Constellation

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    A recently selected NASA heliophysics mission of opportunity, the Electrojet Zeeman Imaging Explorer (EZIE), will study the electric currents that play a crucial role in the interactions between Earth and the surrounding magnetosphere. The aurora is a spectacular manifestation of these interactions. EZIE consists of three 6U CubeSats flying in a pearls-on-a-string orbit configuration, each carrying a Microwave Electrojet Magnetogram (MEM) instrument. Four beams on each satellite measure polarimetric radiances that contain the magnetic signatures of the intense currents in ionospheric plasmas (electrojets) based on the Zeeman splitting of molecular oxygen thermal emissions. This novel measurement technique allows for the remote sensing of the electrojets at altitudes notoriously difficult to measure in situ. The EZIE constellation will provide, for the first time, measurements with the spatial and temporal resolution required to distinguish between proposed hypotheses for the physical mechanisms behind the auroral and equatorial electrojets. A series of observing system simulation experiments demonstrate how EZIE will explore the impacts of space weather near Earth. Each MEM instrument consists of four compact 118-GHz heterodyne spectropolarimeters, leveraging technologies demonstrated by TEMPEST-D and CubeRRT; the 6U CubeSat bus heritage includes RAVAN, CAT, TEMPEST-D, and CubeRRT. Differential drag maneuvers, akin to those pioneered by CYGNSS and CAT, will be used to manage satellite along-track temporal separation to within 2–10 minutes, eliminating the need for on-board propulsion. EZIE success is possible because of past CubeSat demonstrations and strong commercial partnerships

    Synthesis and characterization of stable ZnO nanoparticles using imidazolium-based ionic liquids and their applications in esterification reaction

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    ZnO nanoparticles have been synthesized from zinc acetate using 1-octyl-3-methylimidazolium hexafluorophosphate as capping agent under microwave irradiation condition in a very short period of time and characterized using UV-visible spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and NH3-TPD analysis. The ZnO NPs have been used as a solid reusable acid catalyst for esterification of carboxylic acids with alcohols

    Bumper catch of oil sardine Sardinella longiceps along Cuddalore coast

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    The oil sardine Sardinella longiceps constitutes the most important pelagic resource sustaining the marine fishery on the west coast of India. Two decades ago, the occurrence of this species along the east coast was considered sporadic and rare. In early eighties, there was report on the unusual landing of this species along Puducherry region. Over the years, there has been an increase in the landings of this species on the east coast especially along the Coromandal coast. In July 2008, there were reports in the local daily news papers that the oil sardine shoals were found to move towards the shore off Devanampattinam fishing village and small boys were also able to have easy access to the fish shoal who handpicked the sardines. Some fishes were also stranded and found dead on the beach. This occurrence is linked to upwelling phenomenon which brings the oxygen depleted cold water from the bottom of the sea due to churning by the water current

    A rationale for continuing mass antibiotic distributions for trachoma

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    BACKGROUND: The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. METHODS: We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. RESULTS: Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. CONCLUSION: Local elimination from a community is theoretically possible, even in the most severely infected communities. However, elimination from larger areas may require repeated biannual treatments and prevention of re-introduction from outside to treated areas

    Association of Upper Gastrointestinal Surgery of Great Britain and Ireland (AUGIS)/Perioperative Quality Initiative (POQI) consensus statement on intraoperative and postoperative interventions to reduce pulmonary complications after oesophagectomy

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    BACKGROUND: Pulmonary complications are the most common morbidity after oesophagectomy, contributing to mortality and prolonged postoperative recovery, and have a negative impact on health-related quality of life. A variety of single or bundled interventions in the perioperative setting have been developed to reduce the incidence of pulmonary complications. Significant variation in practice exists across the UK. The aim of this modified Delphi consensus was to deliver clear evidence-based consensus recommendations regarding intraoperative and postoperative care that may reduce pulmonary complications after oesophagectomy. METHODS: With input from a multidisciplinary group of 23 experts in the perioperative management of patients undergoing surgery for oesophageal cancer, a modified Delphi method was employed. Following an initial systematic review of relevant literature, a range of anaesthetic, surgical, and postoperative care interventions were identified. These were then discussed during a two-part virtual conference. Recommendation statements were drafted, refined, and agreed by all attendees. The level of evidence supporting each statement was considered. RESULTS: Consensus was reached on 12 statements on topics including operative approach, pyloric drainage strategies, intraoperative fluid and ventilation strategies, perioperative analgesia, postoperative feeding plans, and physiotherapy interventions. Seven additional questions concerning the perioperative management of patients undergoing oesophagectomy were highlighted to guide future research. CONCLUSION: Clear consensus recommendations regarding intraoperative and postoperative interventions that may reduce pulmonary complications after oesophagectomy are presented

    A Retrospective Study of Non-Communicable Diseases amongst Blue-Collar Migrant Workers in Qatar

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    BACKGROUND: South Asian workers have a greater predisposition to non-communicable diseases (NCDs) that is exacerbated by migration and length of residence in host countries. Aims: To examine the association between length of residence in Qatar with diagnosis of NCDs in male blue-collar workers. METHODS: A retrospective investigation of the electronic health records (EHRs) of 119,581 clinical visits by 58,342 patients was conducted. Data included age, nationality and confirmed ICD-10 diagnosis. Based on duration of residence, the population was divided into groups: ≤6 months, 6–12 months, 1–≤2 years, 2–≤5 years, 5–≤6 years, >6 years. It was assumed that the group that had been resident in Qatar for ≤6 months represented diseases that had been acquired in their countries of origin. Results: South Asian (90%) patients presented with NCDs at a younger (mean ± SD age of 34.8 ± 9.0 years) age. Diabetes and hypertension were higher in those who had just arrived (<6 months’ group), compared to the other durations of residence groups. Conversely, acute respiratory infections, as well as dermatitis and eczema, all increased, perhaps a consequence of shared living/working facilities. Only patients with diabetes and hypertension visited the clinic multiple times, and the cost of medication for these NCDs was affordable, relative to earnings. DISCUSSION/CONCLUSIONS: Blue-collar workers were predominantly South Asian, from lower socioeconomic classes, with early onset chronic NCDs. Notably, residence in Qatar gave them better access to affordable, significantly subsidized healthcare, leading to effective management of these chronic conditions

    Beta-2-transferrin to detect cerebrospinal fluid pleural effusion: a case report

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    Abstract Introduction Pleural effusion secondary to ventriculoperitoneal shunt insertion is a rare and potentially life-threatening occurrence. Case presentation We describe a 14-month-old Caucasian boy who had a ventriculoperitoneal shunt inserted for progressive hydrocephalus of unknown etiology. Two and a half months post-shunt insertion, the patient presented with mild respiratory distress. A chest radiograph revealed a large right pleural effusion and a shunt series demonstrated an appropriately placed distal catheter tip. A subsequent abdominal ultrasound revealed marked ascites. Fluid drained via tube thoracostomy was sent for beta-2-transferrin electrophoresis. A positive test was highly suggestive of cerebral spinal fluid hydrothorax. Post-externalization of the ventriculoperitoneal shunt, the ascites and pleural effusion resolved. Conclusion Testing for beta-2-transferrin protein in pleural fluid may serve as a useful technique for diagnosing cerebrospinal fluid hydrothorax in patients with ventriculoperitoneal shunts

    Reduction and Return of Infectious Trachoma in Severely Affected Communities in Ethiopia

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    Trachoma is one of the leading causes of blindness in the developing world. The World Health Organization has a multi-pronged approach to controlling the ocular chlamydial infection that causes the disease, including distributing antibiotics to entire communities. Even a single community treatment dramatically reduces the prevalence of the infection. Unfortunately, infection returns back into communities after treatment, at least in severely affected areas such as rural Ethiopia. Here, we assess whether additional scheduled treatments in 16 communities in the Gurage area of Ethiopia further reduce infection, and whether the disease returns after distributions are stopped. In communities with the highest levels of trachoma ever studied, we find that repeated mass oral azithromycin distributions gradually reduce the prevalence of trachoma infection in a community, as long as these treatments are given frequently enough and to enough people in the community. Unfortunately, infection returns into the communities after the last treatment. Sustainable changes or complete local elimination of infection will be necessary to stop the return of ocular chlamydial in communities with very high prevalence of the disease

    Atypical clinical presentation and long-term survival in a patient with optic nerve medulloepithelioma: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Medulloepithelioma is a rare congenital tumor of the primitive medullary neuroepithelium. A significant proportion of patients with medulloepithelioma arising from the optic nerve die from intracranial spread or cerebral metastasis. Because it has no known distinct clinical features and because of its low frequency, this tumor presents within the first two to six years of life and is usually misdiagnosed clinically as a different type of optic nerve tumor. Here, we describe a new and atypical case of medulloepithelioma of the optic nerve in a 12-year-old boy. To the best of our knowledge, he is the oldest reported patient to present with this disease and, now as an adult, has the longest documented period of disease-free survival.</p> <p>Case presentation</p> <p>A 12-year-old Caucasian boy with headache and unilateral amaurosis was referred for a presumed optic nerve glioma to our hospital. A computed tomography scan showed optic nerve enlargement, and fundoscopy showed a whitish mass at the optic disc. Our patient had been followed at his local hospital for four years for an 'optic disc cyst' with no change or progression. He experienced mild progressive visual impairment during that period. He was admitted for resection, and a histopathological analysis revealed a medulloepithelioma of the optic nerve. Supplemental orbital radiotherapy was performed. He remained disease-free for 25 years.</p> <p>Conclusions</p> <p>Medulloepithelioma of the optic nerve can clinically mimic more common pediatric tumors, such as optic glioma, meningioma, or retinoblastoma. Thus, medulloepithelioma should be included in the differential diagnoses of pediatric optic nerve lesions. Fundoscopy in these patients may provide relevant information for diagnosis. Anterior optic nerve medulloepitheliomas may behave differently from and have a better prognosis than medulloepitheliomas that have a more posterior location. Our case report illustrates that long-term survival can be achieved in patients with this malignant tumor.</p
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