20,797 research outputs found

    Matching pursuits video coding: dictionaries and fast implementation

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    Posterolateral Elbow Dislocation with Ipsilateral Fractures of Head and Distal End Radius

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    Elbow dislocation associated with ipsilateral fracture head and distal end radius is a rare pattern of Injury, although it is common for elbow dislocation and radius fractures to occur separately. We report a case of 35 year-old male who had a posterolateral elbow dislocation with ipsilateral fractures of head and distal end radius that underwent closed reduction and POP application and outcome is excellent with 9 months of follow-up

    Thermodynamic Losses in a Gas Spring: Comparison of Experimental and Numerical Results

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    Reciprocating-piston devices can be used as high-efficiency compressors and/or expanders. With an optimal valve design and by carefully adjusting valve timing, pressure losses during intake and exhaust can be largely reduced. The main loss mechanism in reciprocating devices is then the thermal irreversibility due to the unsteady heat transfer between the compressed/expanded gas and the surrounding cylinder walls. In this paper, pressure, volume and temperature measurements in a piston-cylinder crankshaft driven gas spring are compared to numerical results. The experimental apparatus experiences mass leakage while the CFD code predicts heat transfer in an ideal closed gas spring. Comparison of experimental and numerical results allows one to better understand the loss mechanisms in play. Heat and mass losses in the experiment are decoupled and the system losses are calculated over a range of frequencies. As expected, compression and expansion approach adiabatic processes for higher frequencies, resulting in higher efficiency. The objective of this study is to observe and explain the discrepancies obtained between the computational and experimental results and to propose further steps to improve the analysis of the loss mechanisms

    RF communication with implantable wireless device: effects of beating heart on performance of miniature antenna

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    The frequency response of an implantable antenna is key to the performance of a wireless implantable sensor. If the antenna detunes significantly, there are substantial power losses resulting in loss of accuracy. One reason for detuning is because of a change in the surrounding environment of an antenna. The pulsating anatomy of the human heart constitutes such a changing environment, so detuning is expected but this has not been quantified dynamically before. Four miniature implantable antennas are presented (two different geometries) along with which are placed within the heart of living swine the dynamic reflection coefficients. These antennas are designed to operate in the short range devices frequency band (863-870 MHz) and are compatible with a deeply implanted cardiovascular pressure sensor. The measurements recorded over 27 seconds capture the effects of the beating heart on the frequency tuning of the implantable antennas. When looked at in the time domain, these effects are clearly physiological and a combination of numerical study and posthumous autopsy proves this to be the case, while retrospective simulation confirms this hypothesis. The impact of pulsating anatomy on antenna design and the need for wideband implantable antennas is highlighted

    Factors Associated with Tuberculosis and Rifampicin-Resistant Tuberculosis amongst Symptomatic Patients in India: A Retrospective Analysis

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    Background Tuberculosis remains a major public health challenge for India. Various studies have documented different levels of TB and multi-drug resistant (MDR) TB among diverse groups of the population. In view of renewed targets set under the End TB strategy by 2035, there is an urgent need for TB diagnosis to be strengthened. Drawing on data from a recent, multisite study, we address key questions for TB diagnosis amongst symptomatics presenting for care: are there subgroups of patients that are more likely than others, to be positive for TB? In turn, amongst these positive cases, are there factors—apart from treatment history—that may be predictive for multi-drug resistance? Methods We used data from a multi-centric prospective demonstration study, conducted from March 2012 to December 2013 in 18 sub-district level TB programme units (TUs) in India and covering a population of 8.8 million. In place of standard diagnostic tests, upfront Xpert MTB/RIF testing was offered to all presumptive TB symptomatics. Here, using data from this study, we used logistic regression to identify association between risk factors and TB and Rifampicin-Resistant TB among symptomatics enrolled in the study. Results We find that male gender; history of TB treatment; and adult age compared with either children or the elderly are risk factors associated with high TB detection amongst symptomatics, across the TUs. While treatment history is found be a significant risk factor for rifampicin-resistant TB, elderly (65+ yrs) people have significantly lower risk than other age groups. However, pediatric TB cases have no less risk of rifampicin resistance as compared with adults (OR 1.23 (95% C.I. 0.85–1.76)). Similarly, risk of rifampicin resistance among both the genders was the same. These patterns applied across the study sites involved. Notably in Mumbai, amongst those patients with microbiological confirmation of TB, female patients showed a higher risk of having MDR-TB than male patients. Conclusion Our results cast fresh light on the characteristics of symptomatics presenting for care who are most likely to be microbiologically positive for TB, and for rifampicin resistance. The challenges posed by TB control are complex and multifactorial: evidence from diverse sources, including retrospective studies such as that addressed here, can be invaluable in informing future strategies to accelerate declines in TB burden

    Credit derivatives pricing with stochastic volatility models

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    This paper proposes a model for pricing credit derivatives in a defaultable HJM framework. The model features hump-shaped, level dependent, and unspanned stochastic volatility, and accommodates a correlation structure between the stochastic volatility, the default-free interest rates, and the credit spreads. The model is finite-dimensional, and leads (a) to exponentially affine default-free and defaultable bond prices, and (b) to an approximation for pricing credit default swaps and swaptions in terms of defaultable bond prices with varying maturities. A numerical study demonstrates that the model captures stylized various features of credit default swaps and swaptions. © 2013 World Scientific Publishing Company

    Functional genomic analysis and neuroanatomical localization of miR-2954, a song-responsive sex-linked microRNA in the zebra finch

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    Natural experience can cause complex changes in gene expression in brain centers for cognition and perception, but the mechanisms that link perceptual experience and neurogenomic regulation are not understood. MicroRNAs (miRNAs or miRs) have the potential to regulate large gene expression networks, and a previous study showed that a natural perceptual stimulus (hearing the sound of birdsong in zebra finches) triggers rapid changes in expression of several miRs in the auditory forebrain. Here we evaluate the functional potential of one of these, miR-2954, which has been found so far only in birds and is encoded on the Z sex chromosome. Using fluorescence in situ hybridization and immunohistochemistry, we show that miR-2954 is present in subsets of cells in the sexually dimorphic brain regions involved in song production and perception, with notable enrichment in cell nuclei. We then probe its regulatory function by inhibiting its expression in a zebra finch cell line (G266) and measuring effects on endogenous gene expression using Illumina RNA sequencing (RNA-seq). Approximately 1000 different mRNAs change in expression by 1.5-fold or more (adjusted p < 0.01), with increases in some but not all of the targets that had been predicted by Targetscan. The population of RNAs that increase after miR-2954 inhibition is notably enriched for ones involved in the MAP Kinase (MAPK) pathway, whereas the decreasing population is dominated by genes involved in ribosomes and mitochondrial function. Since song stimulation itself triggers a decrease in miR-2954 expression followed by a delayed decrease in genes encoding ribosomal and mitochondrial functions, we suggest that miR-2954 may mediate some of the neurogenomic effects of song habituation

    A survey for the Critically Endangered Liben Lark Heteromirafra archeri in Somaliland, north-western Somalia

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    The Critically Endangered Archer's Lark (now Liben Lark) Heteromirafra archeri was formerly considered to be endemic to north-western Somalia and known only from the Tog Wajaale Plain, where 18 specimens were collected between 1918 and 1922. Fifteen visits between 1970 and 2008 failed to relocate the species there, although popula- tions are now known from adjacent Ethiopia. We conducted three days of intensive surveys on the Tog Wajaale Plain in May 2010. Despite the three other lark species present being in full display, and H. archeri being recorded to have bred in early June, no Liben Larks were found. Vegetation structure surveys indicated that the plain has a taller and denser growth of grass than either of the other known localities for Liben Lark (the Liben and Jijiga Plains) making Tog Wajaale Plain seem superficially more suitable for the species, which prefers areas of taller grass elsewhere. However, previous large-scale agricultural activities may have altered the composition of grass species and precipitated the observed invasion of exotic weeds, notably Parthenium hysterophorus. Importantly, the Tog Wajaale Plain has a greater density of bushes than either the Liben or Jijiga Plains, possibly making ground-nesting birds more susceptible to predation by perch hunters.The authors are very grateful for the support provided by a British Ornithologists’ Union research grant and for encouragement from Paul Donald and Nigel Collar. Their visit to Somaliand was additionally supported by Birding Africa (www.birdingafrica.com), and a Small Grant from the Royal Society for the Protection of Birds.This is the author accepted manuscript. The final version is available from Taylor & Francis at http://dx.doi.org/10.2989/00306525.2015.104967

    Iatrogenic Right Sided Infective Endocarditis in Children with CHD

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    Background: Right sided endocarditis (IE) occurs predominantly in intravenous drug abusers, and occasionally acquired in hospital as a result of contaminated intravascular devices. The iatrogenic IE of tricuspid valve in children treated with intravenous (IV) injections for various unrelated conditions is not reported in literature. Objective: Aim is to report clinical outcome, microbiological and echocardiographic presentation of iatrogenic right sided IE in 4 children. Materials and methods: In a span of 3 months four children, age ranging from 1 month to 5 years, three females and one male, who presented with prolonged history of fever formed the material for this study. Two cases had ventricular septal defect (VSD), one had a small atrial septal defect (ASD) and one patient had tetralogy of Fallot (TOF). The blood culture grew coagulase negative staphylococcus in two patients and gram negative bacilli in the one month infant. The diagnosis of tricuspid valve endocarditis was established by transthoracic echocardiography (TTE) in all the four patients. In addition to vegetation on tricuspid valve, the vegetation was also detected in inferior vena cava (IVC) in one case and in another case a large vegetation was seen closing the VSD. Discussion: Right sided endocarditis accounts for only 5 - 10% of cases of IE. It has been estimated that up to 76% of cases of endocarditis among IV drug abusers involve the right heart, compared with only 9% in non-addict patients. The bacterial endocarditis is extremely rare in cases of ASD and TOF. This series of four cases is notable for the iatrogenic IE of tricuspid valve in children treated in the reputed hospitals with IV injections and IV fluids for various unrelated non cardiac conditions. The infection in this series occurred upon previously normal tricuspid valve. Three patients died (75%) and only one survived. Conclusions: Right sided endocarditis can occur in CHD patients when proper aseptic precautions are not taken while treating with IV injections. The blood culture and TTE play an important role in diagnosis and management of right sided IE
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