Impact of global warming on the energetics of lower tropospheric ultra-long waves and the Indian summer monsoon

Analyses of 60 years (1949–2008) of monthly energetics of the zonal waves derived from NCEP/NCAR data indicate that ultra-long waves (waves 1 and 2) dominate the spectrum of lower tropospheric zonal waves during monsoon season (June–September). Westerlies over the Indian subcontinent are a source of energy to wave 1. Two oceanic anticyclones, one over Pacific and the other over Atlantic are sources of energy to wave 2. These two waves are inversely correlated. Climatology of the energetics of ultralong waves for the two epochs 1949–1978 (CLP1) and 1979–2008 (CLP2) of 30 years indicates that the intensity of wave 1 has decreased by about 33% whereas the intensity of wave 2 has increased by about 27%. Northward transport of sensible heat during CLP1 changes to southward during CLP2. Larger generation of zonal mean Available Potential Energy (APE) during CLP2 indicates more heating. A larger conversion of kinetic energy (KE) of wave 1 into APE of wave 1 leads to weakening of wave 1 during CLP2. In case of wave 2, lower rate of conversion of KE to APE leads to stronger wave 2 during CLP2

Accurate detection of uniparental disomy and microdeletions by SNP array analysis in myelodysplastic syndromes with normal cytogenetics.

Progress in the management of patients with myelodysplastic syndromes (MDS) has been hampered by the inability to detect cytogenetic abnormalities in 40-60% of cases. We prospectively analyzed matched pairs of bone marrow and buccal cell (normal) DNA samples from 51 MDS patients by single nucleotide polymorphism (SNP) arrays, and identified somatically acquired clonal genomic abnormalities in 21 patients (41%). Among the 33 patients with normal bone marrow cell karyotypes, 5 (15%) had clonal, somatically acquired aberrations by SNP array analysis, including 4 with segmental uniparental disomies (UPD) and 1 with three separate microdeletions. Each abnormality was detected more readily in CD34+ cells than in unselected bone marrow cells. Paired analysis of bone marrow and buccal cell DNA from each patient was necessary to distinguish true clonal genomic abnormalities from inherited copy number variations and regions with apparent loss of heterozygosity. UPDs affecting chromosome 7q were identified in two patients who had a rapidly deteriorating clinical course despite a low-risk International Prognostic Scoring System score. Further studies of larger numbers of patients will be needed to determine whether 7q UPD detected by SNP array analysis will identify higher risk MDS patients at diagnosis, analogous to those with 7q cytogenetic abnormalities

A test of general relativity from the three-dimensional orbital geometry of a binary pulsar

Binary pulsars provide an excellent system for testing general relativity because of their intrinsic rotational stability and the precision with which radio observations can be used to determine their orbital dynamics. Measurements of the rate of orbital decay of two pulsars have been shown to be consistent with the emission of gravitational waves as predicted by general relativity, providing the most convincing evidence for the self-consistency of the theory to date. However, independent verification of the orbital geometry in these systems was not possible. Such verification may be obtained by determining the orientation of a binary pulsar system using only classical geometric constraints, permitting an independent prediction of general relativistic effects. Here we report high-precision timing of the nearby binary millisecond pulsar PSR J0437-4715, which establish the three-dimensional structure of its orbit. We see the expected retardation of the pulse signal arising from the curvature of space-time in the vicinity of the companion object (the `Shapiro delay'), and we determine the mass of the pulsar and its white dwarf companion. Such mass determinations contribute to our understanding of the origin and evolution of neutron stars.Comment: 5 pages, 2 figure

Author Self-Citation in the General Medicine Literature

Background: Author self-citation contributes to the overall citation count of an article and the impact factor of the journal in which it appears. Little is known, however, about the extent of self-citation in the general clinical medicine literature. The objective of this study was to determine the extent and temporal pattern of author self-citation and the article characteristics associated with author self-citation. Methodology/Principal Findings: We performed a retrospective cohort study of articles published in three high impact general medical journals (JAMA, Lancet, and New England Journal of Medicine) between October 1, 1999 and March 31, 2000. We retrieved the number and percentage of author self-citations received by the article since publication, as of June 2008, from the Scopus citation database. Several article characteristics were extracted by two blinded, independent reviewers for each article in the cohort and analyzed in multivariable linear regression analyses. Since publication, author self-citations accounted for 6.5 % (95 % confidence interval 6.3–6.7%) of all citations received by the 328 articles in our sample. Selfcitation peaked in 2002, declining annually thereafter. Studies with more authors, in cardiovascular medicine or infectious disease, and with smaller sample size were associated with more author self-citations and higher percentage of author selfcitation (all p#0.01). Conclusions/Significance: Approximately 1 in 15 citations of articles in high-profile general medicine journals are autho

A high-performance matrix-matrix multiplication methodology for CPU and GPU architectures

Current compilers cannot generate code that can compete with hand-tuned code in efficiency, even for a simple kernel like matrix–matrix multiplication (MMM). A key step in program optimization is the estimation of optimal values for parameters such as tile sizes and number of levels of tiling. The scheduling parameter values selection is a very difficult and time-consuming task, since parameter values depend on each other; this is why they are found by using searching methods and empirical techniques. To overcome this problem, the scheduling sub-problems must be optimized together, as one problem and not separately. In this paper, an MMM methodology is presented where the optimum scheduling parameters are found by decreasing the search space theoretically, while the major scheduling sub-problems are addressed together as one problem and not separately according to the hardware architecture parameters and input size; for different hardware architecture parameters and/or input sizes, a different implementation is produced. This is achieved by fully exploiting the software characteristics (e.g., data reuse) and hardware architecture parameters (e.g., data caches sizes and associativities), giving high-quality solutions and a smaller search space. This methodology refers to a wide range of CPU and GPU architectures

A methodology for speeding up matrix vector multiplication for single/multi-core architectures

In this paper, a new methodology for computing the Dense Matrix Vector Multiplication, for both embedded (processors without SIMD unit) and general purpose processors (single and multi-core processors, with SIMD unit), is presented. This methodology achieves higher execution speed than ATLAS state-of-the-art library (speedup from 1.2 up to 1.45). This is achieved by fully exploiting the combination of the software (e.g., data reuse) and hardware parameters (e.g., data cache associativity) which are considered simultaneously as one problem and not separately, giving a smaller search space and high-quality solutions. The proposed methodology produces a different schedule for different values of the (i) number of the levels of data cache; (ii) data cache sizes; (iii) data cache associativities; (iv) data cache and main memory latencies; (v) data array layout of the matrix and (vi) number of cores

Adjacent level discitis after anterior cervical discectomy and fusion (ACDF): a case report

This report describes a case of spondylodiscitis occurring adjacent to levels at which anterior cervical discectomy and fusion was performed. The objective is to describe a rare cause of spondylodiscitis and discuss its successful management. Post-operative discitis involving the same level is a known occurrence. We report an interesting case of spondylodiscitis occurring at the adjacent level of fusion, and to our knowledge this is the first such case reported in literature. A two-level decompression and fusion was performed at C5–6 and C6–7 levels with PEEK cages and anterior cervical plating in a middle-aged gentleman for persistent axial neck pain and left-sided radiculopathy involving C6 and C7 distribution. After 6 weeks, the patient presented to us with complaints of mild paresthesia in the abdomen and extremities. Radiological investigations including plain radiographs and MRI revealed a surprising finding of discitis at C4–5 level with an associated epidural abscess. In view of the patient’s myelopathic symptoms, surgical debridement and decompression of the spinal cord was performed. The plate and screws were removed, the cages were left intact, and the C4–5 disc level was reconstructed with tricortical iliac crest autograft. No further instrumentation was performed. The biopsy specimen from the disc at C4–5 level grew Serratia marcescens. It was contemplated that C4–5 discitis was initiated by inoculation of bacteria at the superior endplate of C5 by contaminated vertebral pins/drill-bit or screws. Adjacent level discitis is a rare but potentially serious complication of anterior cervical fusion. A high index of suspicion of infection is necessary if the patient complains of new symptoms after anterior cervical fusion. Thorough assessment and aggressive treatment is necessary for successful management

Optimised laser microdissection of the human ocular surface epithelial regions for microarray studies

Background The most important challenge of performing insitu transcriptional profiling of the human ocular surface epithelial regions is obtaining samples in sufficient amounts, without contamination from adjacent tissue, as the region of interest is microscopic and closely apposed to other tissues regions. We have effectively collected ocular surface (OS) epithelial tissue samples from the Limbal Epithelial Crypt (LEC), limbus, cornea and conjunctiva of post-mortem cadaver eyes with laser microdissection (LMD) technique for gene expression studies with spotted oligonucleotide microarrays and Gene 1.0 ST arrays. Methods Human donor eyes (4 pairs for spotted oligonucleotide microarrays, 3 pairs for Gene 1.0 ST arrays) consented for research were included in this study with due ethical approval of the Nottingham Research Ethics Committee. Eye retrieval was performed within 36 hours of post-mortem period. The dissected corneoscleral buttons were immersed in OCT media and frozen in liquid nitrogen and stored at −80°C till further use. Microscopic tissue sections of interest were taken on PALM slides and stained with Toluidine Blue for laser microdissection with PALM microbeam systems. Optimisation of the laser microdissection technique was crucial for efficient and cost effective sample collection. Results The starting concentration of RNA as stipulated by the protocol of microarray platforms was taken as the cut-off concentration of RNA samples in our studies. The area of LMD tissue processed for spotted oligonucleotide microarray study ranged from 86,253 μm2 in LEC to 392,887 μm2 in LEC stroma. The RNA concentration of the LMD samples ranged from 22 to 92 pg/μl. The recommended starting concentration of the RNA samples used for Gene 1.0 ST arrays was 6 ng/5 μl. To achieve the desired RNA concentration the area of ocular surface epithelial tissue sample processed for the Gene 1.0 ST array experiments was approximately 100,0000 μm2 to 130,0000 μm2. RNA concentration of these samples ranged from 10.88 ng/12 μl to 25.8 ng/12 μl, with the RNA integrity numbers (RIN) for these samples from 3.3 to 7.9. RNA samples with RIN values below 2, that had failed to amplify satisfactorily were discarded. Conclusions The optimised protocol for sample collection and laser microdissection improved the RNA yield of the insitu ocular surface epithelial regions for effective microarray studies on spotted oligonucleotide and affymetrix platforms

Radio pulsar populations

The goal of this article is to summarize the current state of play in the field of radio pulsar statistics. Simply put, from the observed sample of objects from a variety of surveys with different telescopes, we wish to infer the properties of the underlying sample and to connect these with other astrophysical populations (for example supernova remnants or X-ray binaries). The main problem we need to tackle is the fact that, like many areas of science, the observed populations are often heavily biased by a variety of selection effects. After a review of the main effects relevant to radio pulsars, I discuss techniques to correct for them and summarize some of the most recent results. Perhaps the main point I would like to make in this article is that current models to describe the population are far from complete and often suffer from strong covariances between input parameters. That said, there are a number of very interesting conclusions that can be made concerning the evolution of neutron stars based on current data. While the focus of this review will be on the population of isolated Galactic pulsars, I will also briefly comment on millisecond and binary pulsars as well as the pulsar content of globular clusters and the Magellanic Clouds.Comment: 16 pages, 6 figures, to appear in Proceedings of ICREA Workshop on The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain, 2010 April 12-16 (Springer

Factors influencing quality of life following lower limb amputation for peripheral arterial occlusive disease: a systematic review of the literature

Background: The majority of lower limb amputations are undertaken in people with peripheral arterial occlusive disease,\ud and approximately 50% have diabetes. Quality of life is an important outcome in lower limb amputations; little is known\ud about what influences it, and therefore how to improve it.\ud Objectives: The aim of this systematic review was to identify the factors that influence quality of life after lower limb\ud amputation for peripheral arterial occlusive disease.\ud Methods: MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science and Cochrane databases were searched to identify\ud articles that quantitatively measured quality of life in those with a lower limb amputation for peripheral arterial occlusive\ud disease. Articles were quality assessed by two assessors, evidence tables summarised each article and a narrative\ud synthesis was performed.\ud Study design: Systematic review.\ud Results: Twelve articles were included. Study designs and outcome measures used varied. Quality assessment scores\ud ranged from 36% to 92%. The ability to walk successfully with a prosthesis had the greatest positive impact on quality\ud of life. A trans-femoral amputation was negatively associated with quality of life due to increased difficulty in walking\ud with a prosthesis. Other factors such as older age, being male, longer time since amputation, level of social support and\ud presence of diabetes also negatively affected quality of life.\ud Conclusion: Being able to walk with a prosthesis is of primary importance to improve quality of life for people with lower\ud limb amputation due to peripheral arterial occlusive disease. To further understand and improve the quality of life of this\ud population, there is a need for more prospective longitudinal studies, with a standardised outcome measure