420 research outputs found
Joint Spectrum Sensing and Resource Allocation for OFDM-based Transmission with a Cognitive Relay
In this paper, we investigate the joint spectrum sensing and resource
allocation problem to maximize throughput capacity of an OFDM-based cognitive
radio link with a cognitive relay. By applying a cognitive relay that uses
decode and forward (D&F), we achieve more reliable communications, generating
less interference (by needing less transmit power) and more diversity gain. In
order to account for imperfections in spectrum sensing, the proposed schemes
jointly modify energy detector thresholds and allocates transmit powers to all
cognitive radio (CR) subcarriers, while simultaneously assigning subcarrier
pairs for secondary users (SU) and the cognitive relay. This problem is cast as
a constrained optimization problem with constraints on (1) interference
introduced by the SU and the cognitive relay to the PUs; (2) miss-detection and
false alarm probabilities and (3) subcarrier pairing for transmission on the SU
transmitter and the cognitive relay and (4) minimum Quality of Service (QoS)
for each CR subcarrier. We propose one optimal and two sub-optimal schemes all
of which are compared to other schemes in the literature. Simulation results
show that the proposed schemes achieve significantly higher throughput than
other schemes in the literature for different relay situations.Comment: EAI Endorsed Transactions on Wireless Spectrum 14(1): e4 Published
13th Apr 201
SGLT-2 Inhibitors in Heart Failure:Current Management, Unmet Needs, and Therapeutic Prospects
Insilico Molecular Docking - A tool to understand the action of Rasaushadhis
Rasashastra, a branch of Ayurveda consists of many metallo-mineral preparations which are explained as highly efficacious in smaller doses and even in shorter duration. We know the functions of Rasaushadhis (herbo-mineral preparations), but we are lacking the knowledge of their Pharmacodynamics which may benefit us in understanding the exact site where, how and which active principle work and at what rate a drug will interact with its target biomolecule. The advent of new Sciences like Bioinformatics has made drug discovery faster and economical. Bioinformatics research focuses on biology at a molecular level by identifying the effect of drugs at the level of individual genes, DNA, RNA and proteins. It utilizes existing information to model disease pathways and identifies precise targets of the drug. The unclearly answered questions can be clarified by understanding and adopting the concept of āInsilico Molecular Dockingā, means a computational study of binding of Ligand to specific Receptor. The action between the receptor and ligand is by selectivity and affinity; Lock and Key concept. It encompasses all theoretical methods and computational techniques to model and the behavior of molecules and by scoring function we can come to know the best suitable receptor for particular ligand. The working methodology includes preparation of Ligand, Receptor, Docking and inspection by X-Ray Crystallography, NMR techniques. The process of standardization is needed in Rasashastra but, there are some difficulties. One can overcome this by understanding the mode of action of Rasaushadhis -Rasabhasmas through molecular Docking which helps in drug discovery and development, optimisation of action and inhibition of harmful effects
A Novel Speech Separation Based On Ica Strategical Classification
ABSTRACT: Monaural conversation splitting is a well-recognized process. Modern research utilize monitored classification methods to estimate the ideal binary cover up (IBM) inorder to address the issue. In a supervised learning structure, the issue of generalization to conditions different from those in coaching is most essential. This paper presents techniques that require only a little coaching corpus and can generalize to invisible circumstances. The program uses assistance vector machines to understand category hints and then runs on the rethresholding technique inorder to calculate the IBM. A submission fitting method is used to make generalizations to invisible signal-to-noise rate circumstances and voice action recognition centered variation isused to make generalizations to unseen noise circumstances. Methodical evaluation reveals that the recommended strategy generates top quality IBM estimates under invisible circumstances. Hence in this proposed method, a single channel speech enhancement algorithm is intend to offer by constructing a observational signal and noise signal for single channel speech noise reduction based on Independent component analysis (ICA),thereby noise and original speech can be separated through ICA. Hence Simulation results provides that much better peak signal to noise ratio(PSNR) and denoising effect can be procured by using this algorithm
K-Space at TRECVID 2008
In this paper we describe K-Spaceās participation in
TRECVid 2008 in the interactive search task. For 2008
the K-Space group performed one of the largest interactive
video information retrieval experiments conducted
in a laboratory setting. We had three institutions participating
in a multi-site multi-system experiment. In
total 36 users participated, 12 each from Dublin City
University (DCU, Ireland), University of Glasgow (GU,
Scotland) and Centrum Wiskunde and Informatica (CWI,
the Netherlands). Three user interfaces were developed,
two from DCU which were also used in 2007 as well as
an interface from GU. All interfaces leveraged the same
search service. Using a latin squares arrangement, each
user conducted 12 topics, leading in total to 6 runs per
site, 18 in total. We officially submitted for evaluation 3
of these runs to NIST with an additional expert run using
a 4th system. Our submitted runs performed around
the median. In this paper we will present an overview of
the search system utilized, the experimental setup and a
preliminary analysis of our results
On the analytical formulation of excess noise in avalanche photodiodes with dead space
Simple, approximate formulas are developed to calculate the mean gain and excess noise factor for avalanche photodiodes using the dead-space multiplication theory in the regime of small multiplication width and high applied electric field. The accuracy of the approximation is investigated by comparing it to the exact numerical method using recursive coupled integral equations and it is found that it works for dead spaces up to 15% of the multiplication width, which is substantial. The approximation is also tested for real materials such as GaAs, InP and Si for various multiplication widths, and the results found are accurate within ā¼ 15% of the actual noise, which is a significant improvement over the local-theory noise formula. The results obtained for the mean gain also confirm the recently reported relationship between experimentally determined local ionization coefficients and the enabled non-local ionization coefficients
PBEF1/NAmPRTase/Visfatin: a potential malignant astrocytoma/glioblastoma serum marker with prognostic value
Malignant astrocytomas comprise anaplastic astrocytoma (AA; grade III) and Glioblastoma (GBM; grade IV). GBM is the most malignant with a median survival of 10-12 months in patients. Using cDNA microarray based expression profiling of different grades of astrocytomas, we identified several fold increased levels of PBEF1 transcripts in GBM samples. Pre-B-cell colony enhancing factor 1 gene (PBEF1) encodes Nicotinamide phosphoribosyltransferase (NAmPRTase), which catalyses the rate limiting step in the salvage pathway of NAD metabolism in mammalian cells. Further validation using real time RT-qPCR on an independent set of tumor samples (n=91) and normal brain samples (n=9), GBM specific higher expression of PBEF1 was confirmed. Immunohistochemical staining for PBEF1 on a subset of the above samples largely reinforced our finding. We carried out ELISA analysis on serum samples of astrocytoma patients to determine whether this protein levels would correlate with the presence of tumor and tumor grade. PBEF1 serum levels were substantially elevated in many of the AA and GBM patients. Statistical analysis of these data indicates that in patients with astrocytoma, serum PBEF1 levels correlate with tumor grade and is highest in GBM. Immunohistochemical analysis of an independent set of 51 retrospective GBM cases with known survival data revealed that PBEF1 expression in the tumor tissue along with its co-expression with p53 was associated with poor survival. Thus, we have identified PBEF1 as a potential malignant astrocytoma serum marker and prognostic indicator among GBMs
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Influence of Human Factors on Cyber Security within Healthcare Organisations: A Systematic Review
Background: Cybersecurity is increasingly becoming a prominent concern among healthcare providers in adopting digital technologies for improving the quality of care delivered to patients. The recent reports on cyber attacks, such as ransomware and WannaCry, have brought to life the destructive nature of such attacks upon healthcare. In complement to cyberattacks, which have been targeted against the vulnerabilities of information technology (IT) infrastructures, a new form of cyber attack aims to exploit human vulnerabilities; such attacks are categorised as social engineering attacks. Following an increase in the frequency and ingenuity of attacks launched against hospitals and clinical environments with the intention of causing service disruption, there is a strong need to study the level of awareness programmes and training activities offered to the staff by healthcare organisations. Objective: The objective of this systematic review is to identify commonly encountered factors that cybersecurity postures of a healthcare organisation, resulting from the ignorance of cyber threat to healthcare. The systematic review aims to consolidate the current literature being reported upon human behaviour resulting in security gaps that mitigate the cyber defence strategy adopted by healthcare organisations. Additionally, the paper also reviews the organisational risk assessment methodology implemented and the policies being adopted to strengthen cybersecurity. Methods: The topic of cybersecurity within healthcare and the clinical environment has attracted the interest of several researchers, resulting in a broad range of literature. The inclusion criteria for the articles in the review stem from the scope of the five research questions identified. To this end, we conducted seven search queries across three repositories, namely (i) PubMedĀ®/MED-LINE; (ii) Cumulative Index to Nursing and Allied Health Literature (CINAHL); and (iii) Web of Science (WoS), using key words related to cybersecurity awareness, training, organisation risk assessment methodologies, policies and recommendations adopted as counter measures within health care. These were restricted to around the last 12 years. Results: A total of 70 articles were selected to be included in the review, which addresses the complexity of cybersecurity measures adopted within the healthcare and clinical environments. The articles included in the review highlight the evolving nature of cybersecurity threats stemming from exploiting IT infrastructures to more advanced attacks launched with the intent of exploiting human vulnerability. A steady increase in the literature on the threat of phishing attacks evidences the growing threat of social engineering attacks. As a countermeasure, through the review, we identified articles that provide methodologies resulting from case studies to promote cybersecurity awareness among stakeholders. The articles included highlight the need to adopt cyber hygiene practices among healthcare professionals while accessing social media platforms, which forms an ideal test bed for the attackers to gain insight into the life of healthcare professionals. Additionally, the review also includes articles that present strategies adopted by healthcare organisations in countering the impact of social engineering attacks. The evaluation of the cybersecurity risk assessment of an organisation is another key area of study reported in the literature that recommends the organisation of European and international standards in countering social engineering attacks. Lastly, the review includes articles reporting on national case studies with an overview of the economic and societal impact of service disruptions encountered due to cyberattacks. Discussion: One of the limitations of the review is the subjective ranking of the authors associated to the relevance of literature to each of the research questions identified. We also acknowledge the limited amount of literature that focuses on human factors of cybersecurity in health care in general; therefore, the search queries were formulated using well-established cybersecurity related topics categorised according to the threats, risk assessment and organisational strategies reported in the literature.</jats:p
Association of diabetes mellitus on cardiac remodeling, quality of life, and clinical outcomes in heart failure with reduced and preserved ejection fraction
Background:
Diabetes mellitus frequently coexists with heart failure (HF), but few studies have compared the associations between diabetes mellitus and cardiac remodeling, quality of life, and clinical outcomes, according to HF phenotype.
Methods and Results:
We compared echocardiographic parameters, quality of life (assessed by the Kansas City Cardiomyopathy Questionnaire), and outcomes (1āyear allācause mortality, cardiovascular mortality, and HF hospitalization) between HF patients with and without type 2 diabetes mellitus in the prospective ASIANāHF (Asian Sudden Cardiac Death in Heart Failure) Registry, as well as communityābased controls without HF. Adjusted Cox proportional hazards models were used to assess the association of diabetes mellitus with clinical outcomes. Among 5028 patients with HF and reduced ejection fraction (HFrEF; EF <40%) and 1139 patients with HF and preserved EF (HFpEF; EF ā„50%), the prevalences of type 2 diabetes mellitus were 40.2% and 45.0%, respectively (P=0.003). In both HFrEF and HFpEF cohorts, diabetes mellitus (versus no diabetes mellitus) was associated with smaller indexed left ventricular diastolic volumes and higher mitral E/eā² ratio. There was a predominance of eccentric hypertrophy in HFrEF and concentric hypertrophy in HFpEF. Patients with diabetes mellitus had lower Kansas City Cardiomyopathy Questionnaire scores in both HFpEF and HFrEF, with more prominent differences in HFpEF (Pinteraction<0.05). In both HFpEF and HFrEF, patients with diabetes mellitus had more HF rehospitalizations (adjusted hazard ratio, 1.27; 95% CI, 1.05ā1.54; P=0.014) and higher 1āyear rates of the composite of allācause mortality/HF hospitalization (adjusted hazard ratio, 1.22; 95% CI, 1.05ā1.41; P=0.011), with no differences between HF phenotypes (Pinteraction>0.05).
Conclusions:
In HFpEF and HFrEF, type 2 diabetes mellitus is associated with smaller left ventricular volumes, higher mitral E/eā² ratio, poorer quality of life, and worse outcomes, with several differences noted between HF phenotypes
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