935 research outputs found
Simultaneous Observations of the Chromosphere with TRACE and SUMER
Using mainly the 1600 angstrom continuum channel, and also the 1216 angstrom
Lyman-alpha channel (which includes some UV continuum and C IV emission),
aboard the TRACE satellite, we observed the complete lifetime of a transient,
bright chromospheric loop. Simultaneous observations with the SUMER instrument
aboard the SOHO spacecraft revealed interesting material velocities through the
Doppler effect existing above the chromospheric loop imaged with TRACE,
possibly corresponding to extended non-visible loops, or the base of an X-ray
jet.Comment: 14 pages, 10 figures, accepted by Solar Physic
Serologic survey for phocid herpesvirus-1 and -2 in marine mammals from Alaska and Russia.
Blood samples were collected from 1,042 marine mammals off the coast of Alaska (USA) and Russia during the period 1978 to 1994. Eight species of pinnipeds were represented. Sera were tested for presence of neutralizing antibodies to both the PB84 isolate of phocid herpesvirus-1 (PhHV-1) and the 7848/Han90 strain of phocid herpesvirus-2 (PhHV-2). Species-specific antibody prevalences ranged from 22% to 77% for PhHV-1 and 11% to 50% for PhHV-2. Species-specific antibody prevalences for PhHV-1 were greater than or equal to prevalences for PhHV-2. For both viruses and each host species, differences in antibody prevalences were not related to: (1) sex, (2) location of capture, or (3) year of collection. Antibody prevalence of PhHV-1 in walruses (Odobenus rosmarus) could be quantitatively predicted as a function of age. These two viruses have distinct biological properties and based on current data the epizootiology of the two viruses is different, as well. No evidence of herpesvirus-induced mortality has been detected in areas included in this survey. Based on results of this survey, neither PhHV-1 nor PhHV-2 are considered significant mortality factors in mammals which inhabit the marine environment off the coast of Alaska or Russia
Same-day discharge after appendectomy for acute appendicitis: a systematic review and meta-analysis
Purpose: Patients presenting with acute appendicitis are usually hospitalized for a few days for appendectomy and postoperative recovery. Shortening length of stay may reduce costs and improve patient satisfaction. The purpose of this study was to assess the safety of same-day discharge after appendectomy for acute appendicitis. Methods: A systematic review was performed according to PRISMA guidelines. A literature search of EMBASE, Ovid MEDLINE, Web of Science, Cochrane Central, and Google Scholar was conducted from inception to April 14, 2020. Two reviewers independently screened the literature and selected studies that addressed discharge on the same calendar day as the appendectomy. Risk of bias was assessed with the ROBINS-I tool. Main outcomes were hospital readmission, complications, and unplanned hospital visits in the postoperative course. A random effects model was used to pool risk ratios for the main outcomes. Results: Of the 1912 articles screened, 17 comparative studies and 8 non-comparative studies met the inclusion criteria. Most only included laparoscopic procedure for uncomplicated appendicitis. Most studies were considered at moderate or serious risk of bias. In meta-analysis, same-day discharge (vs. overnight hospitalization) was not associated with increased rates of readmission, complication, and unplanned hospital visits. Non-comparative studies demonstrated low rates of readmission, complications, and unplanned hospital visits after same-day discharge. Conclusion: This study suggests that same-day discharge after laparoscopic appendectomy for uncomplicated appendicitis is safe without an increased risk of readmission, complications, or unplanned hospital visits. Hence, same-day discharge may be further encouraged in selected patients. Trial registration: PROSPERO registration no. CRD4201811594
Limb Spicules from the Ground and from Space
We amassed statistics for quiet-sun chromosphere spicules at the limb using
ground-based observations from the Swedish 1-m Solar Telescope on La Palma and
simultaneously from NASA's Transition Region and Coronal Explorer (TRACE)
spacecraft. The observations were obtained in July 2006. With the 0.2 arcsecond
resolution obtained after maximizing the ground-based resolution with the
Multi-Object Multi-Frame Blind Deconvolution (MOMFBD) program, we obtained
specific statistics for sizes and motions of over two dozen individual
spicules, based on movies compiled at 50-second cadence for the series of five
wavelengths observed in a very narrow band at H-alpha, on-band and in the red
and blue wings at 0.035 nm and 0.070 nm (10 s at each wavelength) using the
SOUP filter, and had simultaneous observations in the 160 nm EUV continuum from
TRACE. The MOMFBD restoration also automatically aligned the images,
facilitating the making of Dopplergrams at each off-band pair. We studied 40
H-alpha spicules, and 14 EUV spicules that overlapped H-alpha spicules; we
found that their dynamical and morphological properties fit into the framework
of several previous studies. From a preliminary comparison with spicule
theories, our observations are consistent with a reconnection mechanism for
spicule generation, and with UV spicules being a sheath region surrounding the
H-alpha spicules
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