696 research outputs found
Role of atmospheric stability over the Arabian Sea and the unprecedented failure of monsoon 2002
The anomalous behaviour of the monsoon 2002 has been studied. We have made an attempt to combine satellite and other data sources to characterize the thermal stratification over the Arabian Sea during different phases of monsoon 2002. Using NOAA-ATOVSderived atmospheric temperature and moisture profiles, we have calculated a daily stability index (SI) over the entire Indian region and surrounding oceans. The time series of SI clearly brings out the three major significant epochs of monsoon 2002. The relatively dry atmosphere west of 65° E, signifying lack of convection and an unstable atmosphere over the southeast Arabian Sea with west-to-east gradients in water vapour, SI and cloud liquid water content are noted. The unfavourable stratification during July over the entire Arabian Sea has been investigated in detail. The dominant modes of instability oscillations have been seen to be ~ 30 days both over the western and eastern Arabian Sea, while for the high-frequency modes preference was seen over the eastern part. Using the analysed fields of the National Centre for Medium Range Weather Forecasts, the relative contributions of advective and subsidence components in the maintenance of stratification have been investigated. The latter has been found to have played a more dominant role in the deficit monsoon 200
Hummingbird: An Energy-Efficient GPS Receiver for Small Satellites
Global positioning system (GPS) is the most widely adopted localization technique for satellites in low earth orbits (LEOs). To enable many state-of-the-art applications on satellites, the exact position of the satellites is necessary. With the increasing demand for small satellites, the need for a low-power GPS for satellites is also increasing. However, building low-power GPS receivers for small satellites poses significant challenges, mainly due to the high speeds (similar to 7.8 km/s) of satellites and low available energy. While duty cycling the receiver is a possible solution, the high relative Doppler shift among the GPS satellites and the small satellite contributes to an increase in Time to First Fix (TTFF), which negatively impacts energy consumption. Further, if the satellite tumbles, the GPS receiver may not be able to receive signals properly from the GPS satellites, thus leading to an even longer TTFF. In the worst case, the situation may result in no GPS fix due to disorientation of the receiver antenna. In this work, we elucidate the design of a low-cost, low-power GPS receiver for small satellites. We also propose an energy optimization algorithm to improve the TTFF. With the extensive evaluation of our GPS receiver on an operational nanosatellite, we show that up to 96.16% of energy savings can be achieved using our algorithm without significantly compromising (similar to 10 m) the positioning accuracy
Discovering Closely Related Peers of a Person in Social Networks
In social networks, finding a group of similar people of a specified person is meaningful task in many areas like substitution/alternate recommendation system. For a given person, considering hobbies, interests etc., as base forming a group of peers from social networks. Here we propose mutual unique identification group(MUID) algorithm for identifying closely related peers
Circulation characteristics associated with the Inter-Tropical Convergence Zone during northern winter
In this study, circulation characteristics associated with the ITCZ during the winter are examined by using the archives of National Centre for Medium Range Weather Forecasting (NCMRWF). To this end, some of the mean large scale basic meteorological and derived fields surrounding the ITCZ are analysed to examine the ITCZ circulation. It would be expected that during the INDOEX field phase experiment, several remote sensing and special observations be generated. To assess the impact of new remote sensing data in maintaining the structure and intensity of ITCZ circulation, an assimilation experiment is conducted using the high resolution TOVS temperature profile data of NOAA over the Indian Ocean for March 1996. An assimilation for the forthcoming INDOEX field phase duration in 1999 is planned by incorporating all satellite and observational data to be collected to study the dynamics of ITCZ
Sialic acid changes in Dalton's lymphoma-bearing mice after cyclophosphamide and cisplatin treatment
A novel cardiovascular magnetic resonance risk score for predicting mortality following surgical aortic valve replacement
The increasing prevalence of patients with aortic stenosis worldwide highlights a clinical need for improved and accurate prediction of clinical outcomes following surgery. We investigated patient demographic and cardiovascular magnetic resonance (CMR) characteristics to formulate a dedicated risk score estimating long-term survival following surgery. We recruited consecutive patients undergoing CMR with gadolinium administration prior to surgical aortic valve replacement from 2003 to 2016 in two UK centres. The outcome was overall mortality. A total of 250 patients were included (68 ± 12 years, male 185 (60%), with pre-operative mean aortic valve area 0.93 ± 0.32cm2, LVEF 62 ± 17%) and followed for 6.0 ± 3.3 years. Sixty-one deaths occurred, with 10-year mortality of 23.6%. Multivariable analysis showed that increasing age (HR 1.04, P = 0.005), use of antiplatelet therapy (HR 0.54, P = 0.027), presence of infarction or midwall late gadolinium enhancement (HR 1.52 and HR 2.14 respectively, combined P = 0.12), higher indexed left ventricular stroke volume (HR 0.98, P = 0.043) and higher left atrial ejection fraction (HR 0.98, P = 0.083) associated with mortality and developed a risk score with good discrimination. This is the first dedicated risk prediction score for patients with aortic stenosis undergoing surgical aortic valve replacement providing an individualised estimate for overall mortality. This model can help clinicians individualising medical and surgical care.
TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00930735 and ClinicalTrials.gov Identifier: NCT01755936
An Infinite-Dimensional Family of Black-Hole Microstate Geometries
We construct the first explicit, smooth, horizonless black-hole microstate
geometry whose moduli space is described by an arbitrary function of one
variable and is thus infinite-dimensional. This is achieved by constructing the
scalar Green function on a simple D6 anti-D6 background, and using this Green
function to obtain the fully back-reacted solution for a supertube with varying
charge density in this background. We show that this supertube can store
parametrically more entropy than in flat space, confirming the entropy
enhancement mechanism that was predicted using brane probes. We also show that
all the local properties of the fully back-reacted solution can, in fact, be
obtained using the DBI action of an appropriate brane probe. In particular, the
supergravity and the DBI analysis yield identical functional bubble equations
that govern the relative locations of the centers. This indicates that there is
a non-renormalization theorem that protects these functional equations as one
moves in moduli space. Our construction creates configurations that are beyond
the scope of recent arguments that appear to put strong limits on the entropy
that can be found in smooth supergravity solutions.Comment: 46 pages, 1 figure, LaTe
Imaging myocardial carcinoid with T2-STIR CMR
We used T2-STIR (Short Tau Inversion Recovery) cardiovascular magnetic resonance to demonstrate carcinoid tumor metastases to the heart and liver in a 64-year-old woman with a biopsy-proven ileal carcinoid tumor who was referred because of an abnormal echocardiogram
Association between mid-wall late gadolinium enhancement and sudden cardiac death in patients with dilated cardiomyopathy and mild and moderate left ventricular systolic dysfunction
Background—Current guidelines only recommend the use of an implantable cardioverter defibrillator (ICD) in patients with dilated cardiomyopathy (DCM) for the primary prevention of sudden cardiac death (SCD) in those with a left ventricular ejection fraction (LVEF)35%. Patients with a LVEF>35% also have low competing risks of death from non-sudden causes. Therefore, those at high-risk of SCD may gain longevity from successful ICD therapy. We investigated whether late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) identified patients with DCM without severe LV systolic dysfunction at high-risk of SCD. Methods—We prospectively investigated the association between mid-wall late gadolinium enhancement (LGE) and the pre-specified primary composite outcome of SCD or aborted SCD amongst consecutive referrals with DCM and a LVEF≥40% to our center between January 2000 and December 2011, who did not have a pre-existing indication for ICD implantation. Results—Of 399 patients (145 women, median age 50 years, median LVEF 50%, 25.3% with LGE) followed for a median of 4.6 years, 18 of 101 (17.8%) patients with LGE reached the pre-specified end-point, compared to 7 of 298 (2.3%) without (HR 9.2; 95% CI 3.9-21.8; p5% compared to those without LGE were 10.6 (95%CI 3.9-29.4), 4.9 (95% CI 1.3-18.9) and 11.8 (95% CI 4.3-32.3) respectively. Conclusions—Mid-wall LGE identifies a group of patients with DCM and LVEF≥40% at increased risk of SCD and low-risk of non-sudden death who may benefit from ICD implantation
Identification of QTL underlying vitamin E contents in soybean seed among multiple environments
Vitamin E (VE) in soybean seed has value for foods, medicines, cosmetics, and animal husbandry. Selection for higher VE contents in seeds along with agronomic traits was an important goal for many soybean breeders. In order to map the loci controlling the VE content, F5-derived F6 recombinant inbred lines (RILs) were advanced through single-seed-descent (SSD) to generate a population including 144 RILs. The population was derived from a cross between ‘OAC Bayfield’, a soybean cultivar with high VE content, and ‘Hefeng 25’, a soybean cultivar with low VE content. A total of 107 polymorphic simple sequence repeat markers were used to construct a genetic linkage map. Seed VE contents were analyzed by high performance liquid chromatography for multiple years and locations (Harbin in 2007 and 2008, Hulan in 2008 and Suihua in 2008). Four QTL associated with α-Toc (on four linkage groups, LGs), eight QTL associated with γ-Toc (on eight LGs), four QTL associated with δ-Toc (on four LGs) and five QTL associated with total VE (on four LGs) were identified. A major QTL was detected by marker Satt376 on linkage group C2 and associated with α-Toc (0.0012 > P > 0.0001, 5.0% < R2 < 17.0%, 25.1 < α-Toc < 30.1 μg g−1), total VE (P < 0.0001, 7.0% < R2 < 10.0%, 118.2 < total VE < 478.3 μg g−1). A second QTL detected by marker Satt286 on LG C2 was associated with γ-Toc (0.0003 > P > 0.0001, 6.0% < R2 < 13.0%, 141.5 < γ-Toc < 342.4 μg g−1) and total VE (P < 0.0001, 2.0% < R2 < 9.0%, 353.9 < total VE < 404.0 μg g−1). Another major QTL was detected by marker Satt266 on LG D1b that was associated with α-Toc (0.0002 > P > 0.0001, 4.0% < R2 < 6.0%, 27.7 < α-Toc < 43.7 μg g−1) and γ-Toc (0.0032 > P > 0.0001, 3.0% < R2 < 10.0%, 69.7 < γ-Toc < 345.7 μg g−1). Since beneficial alleles were all from ‘OAC Bayfield’, it was concluded that these three QTL would have great potential value for marker assisted selection for high VE content
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