2,751 research outputs found
Direct measurements of the polarization of terrestrial kilometric radiation from Voyagers 1 and 2
Terrestrial radiation measurements obtained with planetary radio astronomy experiments on Voyager-1 and 2 during the early portions of each flight show the signals to be predominantly left-hand circularly polarized. Since these emissions were most probably generated above the Northern Hemisphere auroral zone, it is concluded that the radiation is emitted primarily in the extraordinary mode
Tropospheric gravity waves observed by three closely spaced ST radars
Clear-air radar experiments were carried out on the southern coast of France during the (ALPEX) Alpine experiment program vertically directed stratosphere-troposphere-radars were set up with spacings of about 5 to 6 km. The temporal and spectral characteristics of the vertical velocity fluctuations were examined. The horizontal and vertical properties of gravity waves in the lower atmosphere were analyzed. The techniques used and the first results from this wave study are described
Know the Star, Know the Planet. III. Discovery of Late-Type Companions to Two Exoplanet Host Stars
We discuss two multiple star systems that host known exoplanets: HD 2638 and
30 Ari B. Adaptive optics imagery revealed an additional stellar companion to
both stars. We collected multi-epoch images of the systems with Robo-AO and the
PALM-3000 adaptive optics systems at Palomar Observatory and provide relative
photometry and astrometry. The astrometry indicates that the companions share
common proper motion with their respective primaries. Both of the new
companions have projected separations less than 30 AU from the exoplanet host
star. Using the projected separations to compute orbital periods of the new
stellar companions, HD 2638 has a period of 130 yrs and 30 Ari B has a period
of 80 years. Previous studies have shown that the true period is most likely
within a factor of three of these estimated values. The additional component to
the 30 Ari makes it the second confirmed quadruple system known to host an
exoplanet. HD 2638 hosts a hot Jupiter and the discovery of a new companion
strengthens the connection between hot Jupiters and binary stars. We place the
systems on a color-magnitude diagram and derive masses for the companions which
turn out to be roughly 0.5 solar mass stars.Comment: Accepted to Astronomical Journal, 16 pages, 5 Figure
Comprehensive review of several surfactants in marine environments: fate and ecotoxicity
Surfactants are a commercially important group of chemicals widely used on a global scale. Despite high removal efficiencies during wastewater treatment, their high consumption volumes mean that a certain fraction will always enter aquatic ecosystems, with marine environments being the ultimate sites of deposition. Consequently, surfactants have been detected within marine waters and sediments. However, aquatic environmental studies have mostly focused on the freshwater environment, and marine studies are considerably underrepresented by comparison. The present review aims to provide a summary of current marine environmental fate (monitoring, biodegradation, and bioconcentration) and effects data of 5 key surfactant groups: linear alkylbenzene sulfonates, alcohol ethoxysulfates, alkyl sulfates, alcohol ethoxylates, and ditallow dimethyl ammonium chloride. Monitoring data are currently limited, especially for alcohol ethoxysulfates and alkyl sulfates. Biodegradation was shown to be considerably slower under marine conditions, whereas ecotoxicity studies suggest that marine species are approximately equally as sensitive to these surfactants as freshwater species. Marine bioconcentration studies are almost nonexistent. Current gaps within the literature are presented, thereby highlighting research areas where additional marine studies should focus
Voyager spacecraft radio observations of Jupiter: Initial cruise results
Jupiter's low-frequency radio emission were detected by the planetary radio astronomy instruments onboard the two Voyager spacecraft. The emission is surprisingly similar in morphology but opposite in polarization to the high-frequency Jovian radio noise that were observed with ground-based telescopes for more than two decades. Several possible explanations for the behavior of the low-frequency emission are examined, but none of them is completely satisfactory
Leiomyosarcoma Arising in the Pancreatic Duct: A Case Report and Review of the Current Literature
Context. Leiomyosarcomas are rare malignant smooth muscle tumors that may arise in any organ or tissue that contains smooth muscle, commonly within the gastrointestinal tract. They are most often found in the stomach, large and small intestines, and retroperitoneum. Primary pancreatic leiomyosarcoma is extremely rare, and to the best of our knowledge only 30 cases have been reported in the world literature since 1951. Our case represents the first to have a clear origin from the main pancreatic duct. Case Report. This case was diagnosed in a large, tertiary care center in Tampa, Florida. Pertinent information was obtained from chart review and interdepartmental collaboration. A mass in the tail of the pancreas was identified with large pleomorphic and spindle-shaped cells. Immunohistochemistry for vimentin, smooth muscle actin, and desmin was positive. All remaining immunohistochemical markers performed were negative. The tumor clearly originated from the pancreatic duct wall, filled and expanded the duct lumen, and was covered with a layer of benign biliary epithelium. Conclusion. Leiomyosarcoma of the pancreas is an extremely rare malignancy with few reported cases in the literature. The prognosis is poor, and treatment consists of alleviating symptoms and pain management. To our knowledge, this represents the first reported case demonstrating clear origin of a leiomyosarcoma from the pancreatic duct
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Education Proposals in Trade Competitiveness Legislation
Improvement on America's competitive position in international trade is one of the major issues confronting the 100th Congress. Most legislative proposals have included provisions for increasing the funding levels for Federal education programs, expanding current programs, or authorizing new programs. The primary goal is to improve the productivity of the Nation's workers by raising the skill level of the workforce. Discussions about education's role i n addressing the competitiveness issue have included the contribution of education to productivity growth, comparisons of the educational achievement of American school children with that of their peers in other nations , the educational needs of illiterate adults , and the role of technology in education
Observational study of the association of first insulin type in uncontrolled type 2 diabetes with macrovascular and microvascular disease
<p>Aims: To compare the risk of vascular disease, HbA1c and weight change, between first prescribed insulins in people with type 2 diabetes.</p>
<p>Methods: People included in THIN United Kingdom primary care record database who began insulin (2000–2007) after poor control on oral glucose-lowering agents (OGLD) were grouped by the number of OGLDs in their treatment regimen immediately before starting insulin (n = 3,485). Within OGLD group, Cox regression compared macrovascular (all-cause mortality, myocardial infarction, acute coronary syndrome and stroke) and microvascular disease (peripheral neuropathy, nephropathy, and retinopathy) between insulin type (basal, pre-mix or Neutral Protamine Hagedorn, NPH) while ANCOVAs compared haemoglobin A1c (HbA1c) and weight change.</p>
<p>Results: Mean follow-up was 3.6 years. Rates of incident macrovascular events were similar when basal insulin was compared to pre-mix or NPH, adjusted hazard ratio versus basal: pre-mix 1.08 (95% CI 0.73, 1.59); NPH 1.00 (0.63, 1.58) after two OGLDs, and pre-mix 0.97 (0.46, 2.02); NPH 0.77 (0.32, 1.86) after three OGLDs. An increased risk of microvascular disease in NPH versus basal after 3 OGLDs, adjusted hazard ratio1.87 (1.04, 3.36), was not seen after two agents or in comparisons of basal and pre-mix. At one year, after two OGLDs, weight increase was less with basal compared with pre-mix. After three OGLDs, mean HbA1c had reduced less in basal versus pre-mix or NPH at 6–8 and at 9–11 months, and versus pre-mix at 12–14 months.</p>
<p>Conclusion: We found no difference in the risk of macrovascular events between first insulins in the medium term when started during poor glycaemia control. The increased risk of microvascular events with NPH warrants further study. In certain groups, first use of basal insulin was associated with less gain in weight and decrease in HbA1c compared to other insulins.</p>
Neoadjuvant chemotherapy and trastuzumab versus neoadjuvant chemotherapy followed by post-operative trastuzumab for patients with HER2-positive breast cancer
Neoadjuvant chemotherapy plus trastuzumab (NCT) increases the rate of pathological complete response (pCR) and event-free survival (EFS) compared to neoadjuvant chemotherapy (NC) alone in women with HER2 positive breast cancer (BC). pCR in this setting is associated with improved EFS. Whether NCT preferentially improves EFS in comparison to NC followed by adjuvant trastuzumab initiated postoperatively (NCAT) has not been addressed. Using clinical data from women with HER2 positive BC treated at 7 European institutions between 2007 and 2010 we sought to investigate the impact on breast cancer outcomes of concomitant (NCT) versus sequential (NCAT) treatment in HER2 positive early BC. The unadjusted hazard ratio (HR) for event free survival with NCT compared with NCAT was 0.63 (95% CI 0.37–1.08; p = 0.091). Multivariable analysis revealed that treatment group, tumour size and ER status were significantly associated with EFS from diagnosis. In the whole group NCT was associated with a reduced risk of an event relative to NCAT, an effect that was confined to ER negative (HR: 0.25; 95% CI, 0.10–0.62; p = 0.003) as opposed to ER positive tumours (HR: 1.07; 95% CI, 0.46–2.52; p = 0.869). HER2 positive/ER negative BC treated with NC gain greatest survival benefit when trastuzumab is administered in both the neoadjuvant and adjuvant period rather than in the adjuvant period alone. These data support the early introduction of targeted combination therapy in HER2 positive/ER negative BC
New insulin glargine 300 U/ml versus glargine 100 U/ml in Japanese adults with type 1 diabetes using basal and mealtime insulin : glucose control and hypoglycaemia in a randomized controlled trial (EDITION JP 1)
Aim: To compare efficacy and safety of new insulin glargine 300 U/ml (Gla‐300) with that of insulin glargine 100 U/ml (Gla‐100) in Japanese adults with type 1 diabetes.
Methods: The EDITION JP 1 study (NCT01689129) was a 6‐month, multicentre, open‐label, phase III study. Participants (n = 243) were randomized to Gla‐300 or Gla‐100 while continuing mealtime insulin. Basal insulin was titrated with the aim of achieving a fasting self‐monitored plasma glucose target of 4.4–7.2 mmol/l. The primary endpoint was change in glycated haemoglobin (HbA1c) over 6 months. Safety measures included hypoglycaemia and change in body weight.
Results: Gla‐300 was non‐inferior to Gla‐100 for the primary endpoint of HbA1c change over the 6‐month period {least squares [LS] mean difference 0.13 % [95 % confidence interval (CI) −0.03 to 0.29]}. The annualized rate of confirmed (≤3.9 mmol/l) or severe hypoglycaemic events was 34 % lower with Gla‐300 than with Gla‐100 at night [rate ratio 0.66 (95 % CI 0.48–0.92)] and 20 % lower at any time of day [24 h; rate ratio 0.80 (95 % CI 0.65–0.98)]; this difference was most pronounced during the first 8 weeks of treatment. Severe hypoglycaemia was infrequent. The basal insulin dose increased in both groups (month 6 dose: Gla‐300 0.35 U/kg/day, Gla‐100 0.29 U/kg/day). A between‐treatment difference in body weight change over 6 months favouring Gla‐300 was observed [LS mean difference −0.6 kg (95 % CI −1.1 to −0.0); p = 0.035]. Adverse event rates were comparable between the groups.
Conclusions: In Japanese adults with type 1 diabetes using basal plus mealtime insulin, less hypoglycaemia was observed with Gla‐300 than with Gla‐100, particularly during the night, while glycaemic control did not differ
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