47 research outputs found
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Estimation of LRD present in H.264 video traces using wavelet analysis and proving the paramount of H.264 using OPF technique in wi-fi environment.
While there has always been a tremendous demand for streaming video over
Wireless networks, the nature of the application still presents some challenging
issues. These applications that transmit coded video sequence data over best-effort
networks like the Internet, the application must cope with the changing network
behaviour; especially, the source encoder rate should be controlled based on
feedback from a channel estimator that explores the network intermittently. The
arrival of powerful video compression techniques such as H.264, which advance in
networking and telecommunications, opened up a whole new frontier for multimedia
communications. The aim of this research is to transmit the H.264 coded video
frames in the wireless network with maximum reliability and in a very efficient
manner. When the H.264 encoded video sequences are to be transmitted through
wireless network, it faces major difficulties in reaching the destination. The
characteristics of H.264 video coded sequences are studied fully and their capability
of transmitting in wireless networks are examined and a new approach called
Optimal Packet Fragmentation (OPF) is framed and the H.264 coded sequences are
tested in the wireless simulated environment. This research has three major studies
involved in it. First part of the research has the study about Long Range Dependence
(LRD) and the ways by which the self-similarity can be estimated. For estimating the
LRD a few studies are carried out and Wavelet-based estimator is selected for the
research because Wavelets incarcerate both time and frequency features in the data
and regularly provides a more affluent picture than the classical Fourier analysis.
The Wavelet used to estimate the self-similarity by using the variable called Hurst
Parameter. Hurst Parameter tells the researcher about how a data can behave inside the transmitted network. This Hurst Parameter should be calculated for a more
reliable transmission in the wireless network. The second part of the research deals
with MPEG-4 and H.264 encoder. The study is carried out to prove which encoder is
superior to the other. We need to know which encoder can provide excellent Quality
of Service (QoS) and reliability. This study proves with the help of Hurst parameter
that H.264 is superior to MPEG-4. The third part of the study is the vital part in this
research; it deals with the H.264 video coded frames that are segmented into optimal
packet size in the MAC Layer for an efficient and more reliable transfer in the
wireless network. Finally the H.264 encoded video frames incorporated with the
Optimal Packet Fragmentation are tested in the NS-2 wireless simulated network.
The research proves the superiority of H.264 video encoder and OPF¿s master class
Muscle MRI in periodic paralysis shows myopathy is common and correlates with intramuscular fat accumulation
INTRODUCTION/AIMS: The periodic paralyses are muscle channelopathies: hypokalemic periodic paralysis (CACNA1S and SCN4A variants), hyperkalemic periodic paralysis (SCN4A variants), and Andersen-Tawil syndrome (KCNJ2). Both episodic weakness and disabling fixed weakness can occur. Little literature exists on magnetic resonance imaging (MRI) in muscle channelopathies. We undertake muscle MRI across all subsets of periodic paralysis and correlate with clinical features. METHODS: A total of 45 participants and eight healthy controls were enrolled and underwent T1-weighted and short-tau-inversion-recovery (STIR) MRI imaging of leg muscles. Muscles were scored using the modified Mercuri Scale. RESULTS: A total of 17 patients had CACNA1S variants, 16 SCN4A, and 12 KCNJ2. Thirty-one (69%) had weakness, and 9 (20%) required a gait-aid/wheelchair. A total of 78% of patients had intramuscular fat accumulation on MRI. Patients with SCN4A variants were most severely affected. In SCN4A, the anterior thigh and posterior calf were more affected, in contrast to the posterior thigh and posterior calf in KCNJ2. We identified a pattern of peri-tendinous STIR hyperintensity in nine patients. There were moderate correlations between Mercuri, STIR scores, and age. Intramuscular fat accumulation was seen in seven patients with no fixed weakness. DISCUSSION: We demonstrate a significant burden of disease in patients with periodic paralyses. MRI intramuscular fat accumulation may be helpful in detecting early muscle involvement, particularly in those without fixed weakness. Longitudinal studies are needed to assess the role of muscle MRI in quantifying disease progression over time and as a potential biomarker in clinical trials
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Genomic Profiling of Childhood Tumor Patient-Derived Xenograft Models to Enable Rational Clinical Trial Design.
Accelerating cures for children with cancer remains an immediate challenge as a result of extensive oncogenic heterogeneity between and within histologies, distinct molecular mechanisms evolving between diagnosis and relapsed disease, and limited therapeutic options. To systematically prioritize and rationally test novel agents in preclinical murine models, researchers within the Pediatric Preclinical Testing Consortium are continuously developing patient-derived xenografts (PDXs)-many of which are refractory to current standard-of-care treatments-from high-risk childhood cancers. Here, we genomically characterize 261 PDX models from 37 unique pediatric cancers; demonstrate faithful recapitulation of histologies and subtypes; and refine our understanding of relapsed disease. In addition, we use expression signatures to classify tumors for TP53 and NF1 pathway inactivation. We anticipate that these data will serve as a resource for pediatric oncology drug development and will guide rational clinical trial design for children with cancer
The potential impact of the COVID-19 pandemic on global antimicrobial and biocide resistance:An AMR Insights global perspective
The COVID-19 pandemic presents a serious public health challenge in all countries. However, repercussions of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on future global health are still being investigated, including the pandemic's potential effect on the emergence and spread of global antimicrobial resistance (AMR). Critically ill COVID-19 patients may develop severe complications, which may predispose patients to infection with nosocomial bacterial and/or fungal pathogens, requiring the extensive use of antibiotics. However, antibiotics may also be inappropriately used in milder cases of COVID-19 infection. Further, concerns such as increased biocide use, antimicrobial stewardship/infection control, AMR awareness, the need for diagnostics (including rapid and point-of-care diagnostics) and the usefulness of vaccination could all be components shaping the influence of the COVID-19 pandemic. In this publication, the authors present a brief overview of the COVID-19 pandemic and associated issues that could influence the pandemic's effect on global AMR.</p
Gene content evolution in the arthropods
Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity
Paper-based sensors for rapid detection of virulence factor produced by Pseudomonas aeruginosa
Pyocyanin is a toxin produced by Pseudomonas aeruginosa. Here we describe a novel paper-based electrochemical sensor for pyocyanin detection, manufactured with a simple and inexpensive approach based on electrode printing on paper. The resulting sensors constitute an effective electrochemical method to quantify pyocyanin in bacterial cultures without the conventional time consuming pretreatment of the samples. The electrochemical properties of the paper-based sensors were evaluated by ferri/ferrocyanide as a redox mediator, and showed reliable sensing performance. The paper-based sensors readily allow for the determination of pyocyanin in bacterial cultures with high reproducibility, achieving a limit of detection of 95 nM and a sensitivity of 4.30 μA/μM in standard culture media. Compared to the similar commercial ceramic based sensors, it is a 2.3-fold enhanced performance. The simple in-house fabrication of sensors for pyocyanin quantification allows researchers to understand in vitro adaptation of P. aeruginosa infections via rapid screenings of bacterial cultures that otherwise are expensive and time-consuming
Genetic architecture of laterality defects revealed by whole exome sequencing
Aberrant left-right patterning in the developing human embryo can lead to a broad spectrum of congenital malformations. The causes of most laterality defects are not known, with variants in established genes accounting for <20% of cases. We sought to characterize the genetic spectrum of these conditions by performing whole-exome sequencing of 323 unrelated laterality cases. We investigated the role of rare, predicted-damaging variation in 1726 putative laterality candidate genes derived from model organisms, pathway analyses, and human phenotypes. We also evaluated the contribution of homo/hemizygous exon deletions and gene-based burden of rare variation. A total of 28 candidate variants (26 rare predicted-damaging variants and 2 hemizygous deletions) were identified, including variants in genes known to cause heterotaxy and primary ciliary dyskinesia (ACVR2B, NODAL, ZIC3, DNAI1, DNAH5, HYDIN, MMP21), and genes without a human phenotype association, but with prior evidence for a role in embryonic laterality or cardiac development. Sanger validation of the latter variants in probands and their parents revealed no de novo variants, but apparent transmitted heterozygous (ROCK2, ISL1, SMAD2), and hemizygous (RAI2, RIPPLY1) variant patterns. Collectively, these variants account for 7.1% of our study subjects. We also observe evidence for an excess burden of rare, predicted loss-of-function variation in PXDNL and BMS1- two genes relevant to the broader laterality phenotype. These findings highlight potential new genes in the development of laterality defects, and suggest extensive locus heterogeneity and complex genetic models in this class of birth defects
The genomes of two key bumblebee species with primitive eusocial organization
Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation
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The potential impact of the COVID-19 pandemic on global antimicrobial and biocide resistance : an AMR Insights global perspective
The COVID-19 pandemic presents a serious public health challenge in all countries. However, repercussions of
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on future global health
are still being investigated, including the pandemic’s potential effect on the emergence and spread of global
antimicrobial resistance (AMR). Critically ill COVID-19 patients may develop severe complications, which may
predispose patients to infection with nosocomial bacterial and/or fungal pathogens, requiring the extensive
use of antibiotics. However, antibiotics may also be inappropriately used in milder cases of COVID-19
infection. Further, concerns such as increased biocide use, antimicrobial stewardship/infection control, AMR
awareness, the need for diagnostics (including rapid and point-of-care diagnostics) and the usefulness of
vaccination could all be components shaping the influence of the COVID-19 pandemic. In this publication, the
authors present a brief overview of the COVID-19 pandemic and associated issues that could influence
the pandemic’s effect on global AMR.This study was supported by internal funding.https://academic.oup.com/jacamram2022School of Health Systems and Public Health (SHSPH