1,986 research outputs found
Planetary Wave Activity Observed in Polar Mesospheric Clouds
In this paper, the Solar Backscatter UV spectrometer (SBUV) Polar Mesospheric Cloud (PMC) dataset was investigated for planetary wave activity following the earlier study by Merkel [2002]. To counter the sparse nature of the data, four separate methods of analysis are used in determining if planetary waves are present and how they effect PMC formation. The four methods are histograms (both in frequency of occurrence and mean albedo), periodograms using the Lomb-Scargle method, frequency-wavenumber analysis using a 2D Lomb-Scargle method from Wu et. al [1995], and a temporal (yearly) analysis of the 5, 6.5, and 10 day wave amplitudes. The general result is a strong presence of the 5-day wave in PMC, which agrees with Merkel [2002] who used data extracted from the Student Nitric Oxide Explorer (SNOE) to observe the 5 day wave in PMC. Other period waves were also observed including the 2, 6.5, 10, and 16 day waves - although these waves were not as strong or persistent as the 5 day. Similar to past research, the 2-day wave was observed to be stronger and more frequent in the southern hemisphere. Long term trends in the amplitudes of the 5, 6.5, and 10 day waves showed a quazi two year oscillation that is possibly modulated by the 11 year solar cycle - seen as an increase in period during solar max. The results indicated that planetary wave activity influences both the frequency of occurrence and brightness of PMC through vertical and horizontal transport of water vapor into the summer polar mesopause and dynamically forced small scale temperature fluctuations. This result is concluded from coupling past research observing planetary waves in vertical and horizontal winds, water vapor, and temperature fluctuations
What is the addiction risk associated with tramadol?
Tramadol (Ultram, generic and with acetaminophen in Ultracet) carries a risk of substance abuse (strength of recommendation [SOR]: B, based on case report surveillance programs). While it appears that tramadol's risk of substance abuse is low (SOR: B, based on case report surveillance programs), tramadol is associated with a withdrawal syndrome usually typical of opioid withdrawal (SOR: B, based on case report surveillance programs, and a prospective descriptive study)
When you suspect ACS, which serologic marker is best?
Measurement of troponin levels provides the most sensitive and accurate serologic information in evaluating a patient with acute coronary syndrome (ACS); troponin elevations are more sensitive than elevations of creatine kinase-MB (CK-MB). Isolated elevation of troponin levels increases the likelihood of myocardial infarction (MI) or death, whereas isolated elevation of CK-MB levels doesn't. (Strength of recommendation [SOR] for all statements: A, multiple, large prospective cohort studies.) Repeated measurement of troponin levels at presentation and then 3 and 6 hours afterward increases the diagnostic sensitivity for acute myocardial infarction (AMI) (SOR: A, multiple, small prospective studies)
Do systemic corticosteroids lessen symptoms in acute exacerbations of COPD?
Systemic corticosteroids improve measures of dyspnea in patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) (strength of recommendation [SOR]: A, meta-analysis of 2 small randomized controlled trials). The optimal dose of systemic corticosteroids to achieve these benefits is uncertain. An international consensus panel recommended 30 to 40 mg of oral prednisone daily for 10 to 14 days as a reasonable compromise of efficacy and safety (SOR: C, consensus expert opinion)
What is the best treatment for Osgood-Schlatter disease?
Osgood-Schlatter disease is a common cause of pain and tenderness at the tibial tuberosity in active adolescents. It is typically a self-limited condition that waxes and wanes, but which often takes months to years to resolve entirely. It is best managed with conservative measures (activity modification, ice, anti- inflammatory agents) and time (strength of recommendation [SOR]: B, several case series and retrospective studies). In chronic cases that are refractory to conservative treatment, surgical intervention yields good results, particularly for patients with bony or cartilaginous ossicles. Excision of these ossicles produces resolution of symptoms and return to activity in several weeks (SOR: C, several case series). Corticosteroid injections are not recommended (SOR: C, case reports and expert opinion)
Who should receive vertebroplasty?
Percutaneous vertebroplasty has been used to treat aggressive vertebral hemangiomas, osteoporotic vertebral compression fractures, and vertebral lesions from metastatic disease or myeloma. Consider it for patients with severe acute or chronic pain related to one of these lesions who have failed a reasonable course of medical therapy (strength of recommendation [SOR]: B, based on structured reviews of observational studies). Contraindications include an uncorrectable coagulation disorder, infection in the area, spinal cord compression, destruction of the posterior wall of the vertebral body, and severe degrees of vertebral body collapse (SOR: B, based on structured reviews of observational studies). Pain relief from vertebroplasty for osteoporotic vertebral fractures may be less for older fractures (SOR: C)
What is the diagnostic approach to a patient with leg cramps?
Leg cramps are very common (strength of recommendation [SOR]: C, case series), and most cases have no detectable cause (SOR: C, expert opinion). Arterial vascular disease and neurological diseases are more prevalent among male patients with leg cramps (SOR: C, small case series). History and physical should focus on detecting precipitating factors for iron deficiency anemia (gastrointestinal bleeding, frequent blood donations, menorrhagia), electrolyte imbalance (renal disease, fluid losses), endocrine disorders (thyroid, Addison's disease), neuromuscular disorders (neuropathies and myopathies), and medication use (antidepressants and diuretics). Laboratory testing is guided by the history and physical and may include ferritin, electrolytes, blood sugar, magnesium, zinc, creatinine, blood urea nitrogen, liver function test, and thyroid-stimulating hormone (SOR: C, expert opinion and nonsystematic review)
Most patients gain weight in the 2 years after total knee arthroplasty: comparison to a healthy control group
SummaryObjectiveWhile joint arthroplasty improves the functional ability of persons with severe knee osteoarthritis (OA), the long-term effects of surgical intervention on body mass have not been evaluated. The objective of this study was to determine if a reduction in body mass index (BMI) was present following unilateral total knee arthroplasty (TKA) compared to an age-matched healthy control group who did not have surgery.MethodOne hundred and six adults with unilateral, end-stage knee OA and thirty-one persons without knee pain participated in the prospective longitudinal study. Subjects with OA underwent primary unilateral TKA and received post-operative out-patient physical therapy. Height, weight, quadriceps strength and self-perceived functional ability were measured at baseline and at a 2-year follow-up.ResultsThere was a significant interaction effect between body mass over time and subject group (P=0.017). BMI showed a significant increase over 2 years for the surgical group (P<0.001), but not for the control group (P=0.842). Sixty-six percent of the persons in the surgical group gained weight over the 2 years with an average weight gain of 6.4kg, or 14 pounds, 2 years after their initial physical therapy visit. Educational level, marital status, income level and activity level prior to surgery were not related to post-surgical weight gain.ConclusionThe majority of subjects gain weight after surgery and this cannot be attributed to the effects of aging. Weight gain after TKA should be treated as an independent concern and management of orthopedic impairments will not result in weight loss. Post-operative care should include access to nutrition or weight management professionals in addition to medical and physical therapy services
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