158 research outputs found
Stellar encounters as the origin of distant solar system objects in highly eccentric orbits
The discovery of Sedna places new constraints on the origin and evolution of
our solar system. Here we investigate the possibility that a close encounter
with another star produced the observed edge of the Kuiper belt, at roughly 50
AU, and the highly elliptical orbit of Sedna. We show that a passing star
probably scattered Sedna from the Kuiper Belt into its observed orbit. The
likelihood that a planet at 60-80 AU can be scattered into Sedna's orbit is
roughly 50%; this estimate depends critically on the geometry of the flyby.
Even more interesting, though, is the roughly 10% chance that Sedna was
captured from the outer disk of the passing star. Most captures have very high
inclination orbits; detection of these objects would confirm the presence of
extrasolar planets in our own Solar System.Comment: 9 pages, 3 figure
An orbital fistula complicating anaerobic frontal sinusitis and osteomyelitis
A patient is described with an orbital fistula complicating frontal sinusitis and osteomyelitis of the frontal bone. The fistula was excised, but a fortnight later an acute exacerbation occurred. From the discharging pus a Staphylococcus aureus was cultured and from mucosa obtained during surgery a microaerophilic Streptococcus. These findings led to the diagnosis: synergistic bacterial inflammation of the frontal sinus, with osteomyelitis and orbital cellulitis
A prospective, multi centre, randomized clinical study to compare the efficacy and safety of Ertapenem 3 days versus Ampicillin - Sulbactam 3 days in the treatment of localized community acquired intra-abdominal infection. (T.E.A. Study: Three days Ertapenem vs three days Ampicillin-sulbactam)
<p>Abstract</p> <p>Background</p> <p>The recommendations outlined in the latest guidelines published by the Surgical Infection Society (SIS) and the Infectious Disease Society of America (IDSA) regarding the proper duration of antibiotic therapy in patients with intra-abdominal infections are limited and non-specific. This ambiguity is due mainly to the lack of clinical trials on the topic of optimal duration of therapy. It is well known that the overuse of antibiotics has several important consequences such as increased treatment costs, reduced clinical efficacy, and above all, the increased emergence of antibiotic-resistant pathogens. Ampicillin-Sulbactam is a commonly used "first line" antibiotic for intra-abdominal infections. Ertapenem and Ampicillin-sulbactam are recommended as primary treatment agents for localized peritonitis by both the SIS and IDSA guidelines.</p> <p>Methods/Design</p> <p>This study is a prospective multi-center randomized investigation. The study will be performed in the Departments of General, Emergency, and Transplant Surgery of Sant'Orsola-Malpighi University Hospital in Bologna, Italy, in the General Surgery Department of the Ospedali Riuniti of Bergamo, Italy, and in the Trauma and Emergency Surgery Department of Maggiore Hospital in Bologna, Italy, and will be conducted by all surgeons willing to participate in the study. The inclusion period of the study will take approximately two years before the planned number of 142 enrolled patients is reached.</p> <p>Discussion</p> <p>Ertapenem and Ampicillin-sulbactam are recommended both as primary treatment agents for localized peritonitis by both the SIS and IDSA guidelines. As one of the discussed topic is the optimal duration of the antibiotic therapy and this ambiguity is due mainly to the lack of clinical trials on the topic, the present study aims for obtain precise data.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00630513">NCT00630513</a></p
A plague on five of your houses - statistical re-assessment of three pneumonic plague outbreaks that occurred in Suffolk, England, between 1906 and 1918
<p>Abstract</p> <p>Background</p> <p>Plague is a re-emerging disease and its pneumonic form is a high priority bio-terrorist threat. Epidemiologists have previously analysed historical outbreaks of pneumonic plague to better understand the dynamics of infection, transmission and control. This study examines 3 relatively unknown outbreaks of pneumonic plague that occurred in Suffolk, England, during the first 2 decades of the twentieth century.</p> <p>Methods</p> <p>The Kolmogorov-Smirnov statistical test is used to compare the symptomatic period and the length of time between successive cases (i.e. the serial interval) with previously reported values. Consideration is also given to the case fatality ratio, the average number of secondary cases resulting from each primary case in the observed minor outbreaks (termed <it>R</it><sub><it>minor</it></sub>), and the proportion of individuals living within an affected household that succumb to pneumonic plague via the index case (i.e. the household secondary attack rate (SAR)).</p> <p>Results</p> <p>2 of the 14 cases survived giving a case fatality ratio of 86% (95% confidence interval (CI) = {57%, 98%}). For the 12 fatal cases, the average symptomatic period was 3.3 days (standard deviation (SD) = 1.2 days) and, for the 11 non index cases, the average serial interval was 5.8 days (SD = 2.0 days). <it>R</it><sub><it>minor </it></sub>was calculated to be 0.9 (SD = 1.0) and, in 2 households, the SAR was approximately 14% (95% CI = {0%, 58%}) and 20% (95% CI = {1%, 72%}), respectively.</p> <p>Conclusions</p> <p>The symptomatic period was approximately 1 day longer on average than in an earlier study but the serial interval was in close agreement with 2 previously reported values. 2 of the 3 outbreaks ended without explicit public health interventions; however, non-professional caregivers were particularly vulnerable - an important public health consideration for any future outbreak of pneumonic plague.</p
Abscesso pulmonar de aspiração: análise de 252 casos consecutivos estudados de 1968 a 2004
The Main Belt Comets and ice in the Solar System
We review the evidence for buried ice in the asteroid belt; specifically the questions around the so-called Main Belt Comets (MBCs). We summarise the evidence for water throughout the Solar System, and describe the various methods for detecting it, including remote sensing from ultraviolet to radio wavelengths. We review progress in the first decade of study of MBCs, including observations, modelling of ice survival, and discussion on their origins. We then look at which methods will likely be most effective for further progress, including the key challenge of direct detection of (escaping) water in these bodies
Prediction of marbofloxacin dosage for the pig pneumonia pathogens Actinobacillus pleuropneumoniae and Pasteurella multocida by pharmacokinetic/pharmacodynamic modelling
PK/PD integration data. (DOCX 7 kb
A novel organic-rich meteoritic clast from the outer solar system
The Zag meteorite which is a thermally-metamorphosed H ordinary chondrite contains a primitive xenolitic clast that was accreted to the parent asteroid after metamorphism. The cm-sized clast contains abundant large organic grains or aggregates up to 20μm in phyllosilicate-rich matrix. Here we report organic and isotope analyses of a large (~10μm) OM aggregate in the Zag clast. The X-ray micro-spectroscopic technique revealed that the OM aggregate has sp2 dominated hydrocarbon networks with a lower abundance of heteroatoms than in IOM from primitive (CI,CM,CR) carbonaceous chondrites, and thus it is distinguished from most of the OM in carbonaceous meteorites. The OM aggregate has high D/H and 15N/14N ratios (δD=2,370±74‰ and δ15N=696±100‰), suggesting that it originated in a very cold environment such as the interstellar medium or outer region of the solar nebula, while the OM is embedded in carbonate-bearing matrix resulting from aqueous activities. Thus, the high D/H ratio must have been preserved during the extensive late-stage aqueous processing. It indicates that both the OM precursors and the water had high D/H ratios. Combined with 16O-poor nature of the clast, the OM aggregate and the clast are unique among known chondrite groups. We further propose that the clast possibly originated from D/P type asteroids or trans-Neptunian Objects
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