2,621 research outputs found
Improving Data Integrity in Communication Systems by Designing a New Security Hash Algorithm
The objective of this paper is to design a new secure hash algorithm with final hash code length 512 bits. The proposed hash code algorithm based on the combination of SHA-256 algorithm -with modification in its message expansion- and MD5algorithm based on double-Davis-Mayer scheme to reduce the weakness existing in these functions.In this paper; we modified message expansion for SHA-256 in the proposed algorithm .By using MATLAB, The proposed algorithm has been simulated. And hash code for different messages is obtained using MD5, SHA-256, combination of MD5 and SHA-256 with final hash code length 265 bits algorithms and the proposed algorithm . Hash code of the proposed algorithm is different from hash code obtained by MD5, SHA-256 and combination of MD5 and SHA-256 with final hash code length 256 bits algorithms for the same messages. Avalanche test, with one bit difference and more than one bit difference, is applied toSHA-256, combination of MD5 and SHA-256 with final hash code length 256 bits and the proposed algorithm .The proposed algorithm passed avalanche test with higher probability than SHA-256 and combination of MD5 and SHA-256 with final hash code length 256 bit algorithms .The proposed algorithm is more complicated and more secure
Phase Control and Eclipse Avoidance in Near Rectilinear Halo Orbits
The baseline trajectory proposed for the Gateway is a southern Earth-Moon L2 Near Rectilinear Halo Orbit (NRHO). Designed to avoid eclipses, the NRHO exhibits a resonance with the lunar synodic period. The current investigation details the eclipse behavior in the baseline NRHO. Then, phase control is added to the orbit maintenance algorithm to regulate perilune passage time and maintain the eclipse-free characteristics of the Gateway reference orbit. A targeting strategy is designed to periodically target back to the long-horizon virtual reference if the orbit diverges over time in the presence of additional perturbations
Fluid Film Bearing Fundamentals And Failure Analysis.
Tutorialpg. 161-186Fluid film bearing technology is presented in this tutorial as it applies to turbomachinery equipment. The focus here is on the practical aspects of fluid film journal bearings, as opposed to theoretical analysis. Failure modes and the mechanisms leading to these failures will be discussed, along with techniques used to identify and cure them. The influence of different bearing configurations on the dynamics of rotor bearing systems will also be discussed
Risk factors for Salmonella, Shiga toxin-producing Escherichia coli and Campylobacter occurrence in primary production of leafy greens and strawberries
The microbiological sanitary quality and safety of leafy greens and strawberries were assessed in the primary production in Belgium, Brazil, Egypt, Norway and Spain by enumeration of Escherichia coli and detection of Salmonella, Shiga toxin-producing E. coli (STEC) and Campylobacter. Water samples were more prone to containing pathogens (54 positives out of 950 analyses) than soil (16/1186) and produce on the field (18/977 for leafy greens and 5/402 for strawberries). The prevalence of pathogens also varied markedly according to the sampling region. Flooding of fields increased the risk considerably, with odds ratio (OR) 10.9 for Salmonella and 7.0 for STEC. A significant association between elevated numbers of generic E. coli and detection of pathogens (OR of 2.3 for STEC and 2.7 for Salmonella) was established. Generic E. coli was found to be a suitable index organism for Salmonella and STEC, but to a lesser extent for Campylobacter. Guidelines on frequency of sampling and threshold values for E. coli in irrigation water may differ from region to region
Qualité physico-chimique et contamination métallique des eaux de l’Oued Hassar : impacts des eaux usées de la localité de Mediouna (Périurbain de Casablanca, Maroc)
Une des préoccupations majeures du début du XXIe siècle est la pérennité d’une ressource en eau suffisante pour satisfaire les besoins d’une population en forte croissance dans un contexte mondial marqué par lechangement climatique et ses conséquences hydrologiques. Cette problématique ne se limite pas à la quantité des ressources en eau, mais porte également sur leur qualité qu’il faut aujourd’hui plus que jamais bien gérer. Les activités industrielles, agricoles ou urbaines peuvent modifier la qualité des eaux et les rendre impropres à l’utilisation. C’est le cas de la zone périurbaine du Nord Est du grand Casablanca (Province de Mediouna), où le cours d’eau d’Oued Hassar reçoit, à ciel ouvert, les rejets d’eaux usées de Mediouna dont les impacts écologiques et sanitaires sont multiples. Les résultats des analyses physico-chimiques montrent que les eaux de ce cours d’eau sont caractérisées par une minéralisation importante comme l’indiquent les valeurs élevées de la conductivité électrique et des chlorures. De même, ces eaux présentent une pollution importante confirmée par les valeurs élevées de la DCO, le phosphore total et l’azote ammoniacal. En ce qui concerne les métaux lourds (Cd, Pb, Cr, Cu, Fe et Zn), l’analyse des résultats montre que les concentrations en éléments traces dans les eaux usées de Mediouna et de celles d’oued Hassar ne constituent pas un facteur limitant pour la réutilisation de ces eaux dans l’irrigation.Mots-clés : Casablanca, Oued Hassar, eaux usées, pollution, physicochimie, métaux lourds
Ontological Levels in Histological Imaging
Paper presented at the 9th edition of the Formal Ontology in Information Systems conference, FOIS 2016, July 6–9, 2016, Annecy, FranceThis is the author accepted manuscript. The final version is available from IOS Press via the DOI in this record.In this paper we present an ontological perspective on ongoing work in histological and histopathological imaging involving the quantitative and algorithmic analysis of digitised images of cells and tissues. We present the derivation of consistent histological models from initially captured images of prepared tissue samples as a progression through a number of ontological levels, each populated by its distinctive classes of entities related in systematic ways to entities at other levels. We see this work as contributing to ongoing efforts to provide a consistent and widely accepted suite of ontological resources such as those currently constituting the OBO Foundry, and where possible we draw links between our work and existing ontologies within that suite.This research is supported by EPSRC through funding under grant EP/M023869/1 “Novel context-based segmentation algorithms for intelligent microscopy”
Automatic thresholding from the gradients of region boundaries
We present an approach for automatic threshold segmentation of greyscale images. The procedure is inspired by a reinterpretation of the strategy observed in human operators when adjusting thresholds manually and interactively by means of ‘slider’ controls. The approach translates into two methods. The first one is suitable for single or multiple global thresholds to be applied globally to images and consists of searching for a threshold value that generates a phase whose boundary coincides with the largest gradients in the original image. The second method is a variation, implemented to operate on the discrete connected components of the thresholded phase (i.e. the binary regions) independently. Consequently, this becomes an adaptive local threshold procedure, which operates relative to regions, rather than to local image subsets as is the case in most local thresholding methods previously published. Adding constraints for specifying certain classes of expected objects in the images can improve the output of the method over the traditional ‘segmenting first, then classify’ approach.The research reported in this paper was supported by the Engineering
and Physical Sciences Research Council (EPSRC), UK
through funding under grant EP/M023869/1 ‘Novel contextbased
segmentation algorithms for intelligent microscopy’
Use of evidence to support healthy public policy: a policy effectiveness-feasibility loop
Public policy plays a key role in improving population health and in the control of diseases, including non-communicable diseases.
However, an evidence-based approach to formulating healthy public policy has been difficult to implement, partly on account of barriers
that hinder integrated work between researchers and policy-makers. This paper describes a “policy effectiveness–feasibility loop” (PEFL) that
brings together epidemiological modelling, local situation analysis and option appraisal to foster collaboration between researchers and
policy-makers. Epidemiological modelling explores the determinants of trends in disease and the potential health benefits of modifying
them. Situation analysis investigates the current conceptualization of policy, the level of policy awareness and commitment among key
stakeholders, and what actually happens in practice, thereby helping to identify policy gaps. Option appraisal integrates epidemiological
modelling and situation analysis to investigate the feasibility, costs and likely health benefits of various policy options. The authors illustrate
how PEFL was used in a project to inform public policy for the prevention of cardiovascular diseases and diabetes in four parts of the eastern
Mediterranean. They conclude that PEFL may offer a useful framework for researchers and policy-makers to successfully work together to
generate evidence-based policy, and they encourage further evaluation of this approach
Genotypes Diversity and Virulence Factor screening of Trichomonas vaginalis Isolated from Pregnant Women in Mosul (North of Iraq)
تعد المشعرات المهبلية احد مسببات الامراض المنتقلة جنسياً خصوصاً لدى النساء المثبطات مناعياً مثل الحوامل، جمعت خلال البحث الحالي تم تحديد النساء بعمر (18-45) كمصدر للعينات ، تم جمع (105) عينة بوساطة مسحات ثنائية من عمق المهبل احدها للفحص المجهري المباشر والأخرى للفحص الجزيئي ، تم تقييم الدالة الحامضية للعينات لبيئة المهبل والتي كانت اقل من 4.5 وذلك بمزج قطرة من الافرازات المهبلية مع قطرة من هيدروكسيد البوتاسيوم 10% (فحص ويف)، واعتمد الفحص المجهري كتشخيص مظهري لتحديد وجود الطفيل باستعمال الشريحة الرطبة (16) وصبغة كمزا (11)، من ناحية أخرى اظهر التحري عند المستوى الجزيئي باستعمال تقنية التفاعل التسلسلي لانزيم البلمرة تحديد المورث AP65-1 المسؤول عن وجود بروتين الالتصاق السطحي لدى (8) عينات وبنسبة تحسس (7.5) وتم استعمال تطبيق التضخيم العشوائي للحمض النووي RAPD للكشف عن قيم التباعد والتقارب الوراثي لعينات الحمض النووي المستخلص للطفيلي من خلال تحليل الترحيل الكهربائي لنواتج التضخيم العشوائي ورسم معالم الشجرة الوراثية باعتماد برنامج PAST الاحصائي، توصي الدراسة الحالية بمزيد من الفحوصات ضمن جدول زمني محدد لتقييم إصابات الجهاز التناسلي الغير مرتبطة بأعراض ظاهرة لدى النساء بما في ذلك مخاطر تفاقم الإصابات الثانوية خصوصاً منها الإصابات الفيروسية الخطيرة واعتماد استحداث اللقاحات للمسببات المرضية وايضا استحداث التوجه لاستحداث اللقاح الجزيئية المثبطة للجينات الاساس والمؤثرة في حدوث الاصابة .Trichomonas vaginalis is a causative agent of trichomoniasis , one of the most common non-viral sexually transmitted disease (STD) over all the world, especially in immunocompromised women such as pregnant. Wet smear and Giemsa stain are the current methods used in hospital to diagnosis trichomoniasis. DNA based diagnosis is still to be validated to diagnose the local isolates, the objective of the present study was to compare the conventional methods of disease diagnosis with the DNA-based method to diagnose Trichomonas incidence in local isolates. In the present study, 105 samples were collected from outpatient women (18-45 years) of Maternity hospital in Mosul who showed a classical presentation of Trichomonas infection including foul-smelling vaginal discharge with a pH exceeding 4.5. Samples underwent microscopic examination and nucleic acid detection of AP65-1 gene, the wet smear test showed that 16.18% of the collected specimen were positive while the parasite appeared only in 8.9% of the samples stained with Giemsa dye, the molecular screening for AP65-1gene that encodes for the surface attachment protein showed high sensitivity level of 100 at 50 specificity level in compare with other routine methods, the algorithm was evaluated according to specificity, sensitivity, and predictive values. Random Amplification Polymorphic DNA (RAPD) was achieved to estimate genetic indices among isolated strains. Phylogenetic analysis was performed using PAST (Paleontological statistics software) and dendrogram with neighboring clusters was constructed. According to the outcomes of research, we recommended to utilize a probiotic vaccines and molecular silencing vaccine (like miRNA sense and antisense oligonucleotides) as a treatment in
Cirrhotic cardiomyopathy
Cirrhotic cardiomyopathy is the term used to describe a constellation of features indicative of abnormal heart structure and function in patients with cirrhosis. These include systolic and diastolic dysfunction, electrophysiological changes, and macroscopic and microscopic structural changes. The prevalence of cirrhotic cardiomyopathy remains unknown at present, mostly because the disease is generally latent and shows itself when the patient is subjected to stress such as exercise, drugs, hemorrhage and surgery. The main clinical features of cirrhotic cardiomyopathy include baseline increased cardiac output, attenuated systolic contraction or diastolic relaxation in response to physiologic, pharmacologic and surgical stress, and electrical conductance abnormalities (prolonged QT interval). In the majority of cases, diastolic dysfunction precedes systolic dysfunction, which tends to manifest only under conditions of stress. Generally, cirrhotic cardiomyopathy with overt severe heart failure is rare. Major stresses on the cardiovascular system such as liver transplantation, infections and insertion of transjugular intrahepatic portosystemic stent-shunts (TIPS) can unmask the presence of cirrhotic cardiomyopathy and thereby convert latent to overt heart failure. Cirrhotic cardiomyopathy may also contribute to the pathogenesis of hepatorenal syndrome. Pathogenic mechanisms of cirrhotic cardiomyopathy are multiple and include abnormal membrane biophysical characteristics, impaired β-adrenergic receptor signal transduction and increased activity of negative-inotropic pathways mediated by cGMP. Diagnosis and differential diagnosis require a careful assessment of patient history probing for excessive alcohol, physical examination for signs of hypertension such as retinal vascular changes, and appropriate diagnostic tests such as exercise stress electrocardiography, nuclear heart scans and coronary angiography. Current management recommendations include empirical, nonspecific and mainly supportive measures. The exact prognosis remains unclear. The extent of cirrhotic cardiomyopathy generally correlates to the degree of liver insufficiency. Reversibility is possible (either pharmacological or after liver transplantation), but further studies are needed
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