170 research outputs found

    Performance Analysis of Hierarchical Routing Protocols in Wireless Sensor Networks

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    This work focusses on analyzing the optimization strategies of routing protocols with respect to energy utilization of sensor nodes in Wireless Sensor Network (WSNs). Different routing mechanisms have been proposed to address energy optimization problem in sensor nodes. Clustering mechanism is one of the popular WSNs routing mechanisms. In this paper, we first address energy limitation constraints with respect to maximizing network life time using linear programming formulation technique. To check the efficiency of different clustering scheme against modeled constraints, we select four cluster based routing protocols; Low Energy Adaptive Clustering Hierarchy (LEACH), Threshold Sensitive Energy Efficient sensor Network (TEEN), Stable Election Protocol (SEP), and Distributed Energy Efficient Clustering (DEEC). To validate our mathematical framework, we perform analytical simulations in MATLAB by choosing number of alive nodes, number of dead nodes, number of packets and number of CHs, as performance metrics.Comment: NGWMN with 7th IEEE International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA 2012), Victoria, Canada, 201

    Accounting for Interaction and Individual Specific Effects in an Analysis of International Air Traveler Preferences

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    selection decision based on contingency theory. Previous work has focused on main effects without eploring the significance of interaction or individual heterogeneity effects. Contingency theory suggests contextual and individual factors are important in enhancing model predictions. Using conjoint and ordered probit analyses, we find that including interaction and individual specific intercepts alters the impacts of main effect variables. Furthermore, accounting for interaction and individual heterogeneity increases the predictive ability of the preference model for airline travelers

    The impacts of ICT on the students’ Performance: A Review of Access to Information

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    The study was on the Impact of Information and Communication Technology (ICT) on the students and his/her information to access in the Gomal University, Dera Ismail Khan. A sample of 50 respondents (students) was selected from the department of Political science, Gomal University, Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan. However, related literatures were reviewed from textbooks, journals and past researches. The research instruments were questionnaire which was statically analyzed with contingency tables while the hypotheses were tested by using the mean statistic. The results of the present study showed a diverse response of the student regarding the impact of ICT’s on the students and their access to information

    Empiric transcatheter arterial embolization for massive or recurrent gastrointestinal bleeding: Ten-year experience from a single tertiary care center

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    Purpose In patients with massive or recurrent gastrointestinal bleeding (GIB) which is not amenable to endoscopic therapy, angiographic interventions are often employed. We report our ten-year experience of empiric transcatheter arterial embolization (TAE) for patients with massive or recurrent GIB. Methods All patients who had undergone empiric TAE at our hospital between March 2004 and June 2015 were identified using the institutional radiology information system. A retrospective chart review was performed using a structured pro forma. Technical success rate, 30-day clinical success rate, 30-day mortality rate, and rate of procedural complications were computed. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) version 20. Results A total of 32 patients had undergone empiric TAE for GIB during the study period. The median age of subjects was 56 years and two-thirds of them were male (68.7%). Gastroduodenal (n=24), ileocolic (n=3), left gastric (n=2), right gastroepiploic (n=1), and branches of superior and middle rectal arteries (n=1) were embolized using microcoils (n=25), polyvinyl alcohol particles (n=25), and gelatin sponge (n=3)--either alone or in combination. Technical and 30-day clinical success rates were 96.9% (31/32) and 71.9% (23/32), respectively. The 30-day mortality rate for our cohort was 21.9% (7/32). One patient developed re-bleeding at two days after the initial procedure and required repeat embolization. Coil migration (n=3) and access site hematoma (n=1) were the observed procedural complications. Conclusion Empiric TAE can be a useful treatment option for selected patients with massive or recurrent GIB that is not amenable to endoscopic therapy

    AI-driven optimization of ethanol-powered internal combustion engines in alignment with multiple SDGs: A sustainable energy transition

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    With the escalating requirement for global sustainable energy solutions and the complexities linked with the complete transition to new technologies, internal combustion engines (ICEs) powered with biofuels like ethanol are gaining significance over time. However, problems linked to the performance and emissions of such ICEs necessitate accurate prediction and optimization. The study employed the integration of artificial neural networks (ANN) and multi-level historical design of response surface methodology (RSM) to address these challenges in alignment with the Sustainable Development Goals (SDGs). A single-cylinder spark ignition (SI) engine powered with ethanol-gasoline blends at different loads and speeds was used to gather data. Among six initially trained ANN models, the most efficient model with a regression coefficient (R2) of 0.9952 (training), 0.98579 (validation), 0.98847 (testing), and 0.99307 (overall) was employed to predict outputs such as brake power, brake specific fuel consumption (BSFC), brake thermal energy (BTE), concentration of carbon dioxide (CO2), carbon monoxide (CO), hydrocarbons (HC), and oxides of nitrogen NOx. Predicted outputs were optimized by incorporating RSM. On implementing optimized conditions, it was observed that BP and BTE increased by 19.9%, and 29.8%, respectively. Additionally, CO, and HC emissions experienced substantial reductions of 28.1%, and 40.6%, respectively. This research can help engine producers and researchers make refined decisions and achieve improved performance and emissions. The study directly supports SDG 7, SDG 9, SDG 12, SDG 13, and SGD 17, which call for achieving affordable, clean energy, sustainable industrialization, responsible consumption, and production, taking action on climate change, and partnership to advance the SDGs as a whole respectively

    Antimicrobial activity analysis of extracts of Acacia modesta, Artimisia absinthium, Nigella sativa and Saussurea lappa against Gram positive and Gram negative microorganisms

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    Antimicrobial activity of extracts of certain herbs including Acacia modesta (leaf and stem), Artimisia absinthium (leaf and stem), Nigella sativa (seeds) and i (root) was evaluated against three Gram positive and two Gram negative microorganisms. The Gram positive organisms included Bacillus subtalis (ATCC 6633), Entereococcus faecalis (ATCC 14506) and Staphylococcus aureus (ATCC 6538) and the Gram negative organisms included Pseudomonas aeruginosa (ATCC 27853) and Salmonella typhi (ATCC 14028). Methanolic, hot water and cold water extracts of these plants were taken for antibacterial assay through Discs agar diffusion technique using commercial filter paper discs applied on inoculated Muellar Hinton agar plates. The objective of this study was to explore the curative powers of these herbs that exist in nature as a tool to counter disease causing agents. The maximum zone of inhibition of 18 mm of methanolic extract of N. sativa was observed against B. subtalis and S. aureus. Similarly, the maximum zone of inhibition of 18 mm of cold water extract of N. sativa against S. aureus and methanolic extract of Saussurea lappa against S. aureus and Pseudomonas aeruginosa was also observed. The antibacterial action was compared with the effect of ceftriaxone, ceftriaxone sodium, cefuroxine, ciprofloxacin, gentamycine, levofloxacin, metronidazole and tranexamic acid that were used as standered drugs. Based on the results obtained in this study, it may be concluded that plant extracts of A. modesta, A. absinthium, N. sativa and Saussurea lappa have a stronger and broader spectrum of antimicrobial activity against a number of food borne bacteria.Key words: Herbs, methanolic extract, Acacia modesta, Bacillus subtalis, gentamycine, gram negative, gram positive

    A multi-institutional experience in adventitial cystic disease

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    AbstractBackgroundAdventitial cystic disease (ACD) is an unusual arteriopathy; case reports and small series constitute the available literature regarding treatment. We sought to examine the presentation, contemporary management, and long-term outcomes using a multi-institutional database.MethodsUsing a standardized database, 14 institutions retrospectively collected demographics, comorbidities, presentation/symptoms, imaging, treatment, and follow-up data on consecutive patients treated for ACD during a 10-year period, using Society for Vascular Surgery reporting standards for limb ischemia. Univariate and multivariate analyses were performed comparing treatment methods and factors associated with recurrent intervention. Life-table analysis was performed to estimate the freedom from reintervention in comparing the various treatment modalities.ResultsForty-seven patients (32 men, 15 women; mean age, 43 years) were identified with ACD involving the popliteal artery (n = 41), radial artery (n = 3), superficial/common femoral artery (n = 2), and common femoral vein (n = 1). Lower extremity claudication was seen in 93% of ACD of the leg arteries, whereas patients with upper extremity ACD had hand or arm pain. Preoperative diagnosis was made in 88% of patients, primarily using cross-sectional imaging of the lower extremity; mean lower extremity ankle-brachial index was 0.71 in the affected limb. Forty-one patients with lower extremity ACD underwent operative repair (resection with interposition graft, 21 patients; cyst resection, 13 patients; cyst resection with bypass graft, 5 patients; cyst resection with patch, 2 patients). Two patients with upper extremity ACD underwent cyst drainage without resection or arterial reconstruction. Complications, including graft infection, thrombosis, hematoma, and wound dehiscence, occurred in 12% of patients. Mean lower extremity ankle-brachial index at 3 months postoperatively improved to 1.07 (P < .001), with an overall mean follow-up of 20 months (range, 0.33-9 years). Eight patients (18%) with lower extremity arterial ACD required reintervention (redo cyst resection, one; thrombectomy, three; redo bypass, one; balloon angioplasty, three) after a mean of 70 days with symptom relief in 88%. Lower extremity patients who underwent cyst resection and interposition or bypass graft were less likely to require reintervention (P = .04). One patient with lower extremity ACD required an above-knee amputation for extensive tissue loss.ConclusionsThis multi-institutional, contemporary experience of ACD examines the treatment and outcomes of ACD. The majority of patients can be identified preoperatively; surgical repair, consisting of cyst excision with arterial reconstruction or bypass alone, provides the best long-term symptomatic relief and reduced need for intervention to maintain patency

    Bleeding disorders in the tribe: result of consanguineous in breeding

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    <p>Abstract</p> <p>Objective</p> <p>To determine the frequency and clinical features of bleeding disorders in the tribe as a result of consanguineous marriages.</p> <p>Design</p> <p>Cross Sectional Study</p> <p>Introduction</p> <p>Countries in which consanguinity is a normal practice, these rare autosomal recessive disorders run in close families and tribes. Here we describe a family, living in village Ali Murad Chandio, District Badin, labeled as haemophilia.</p> <p>Patients & Methods</p> <p>Our team visited the village & developed the pedigree of the whole extended family, up to seven generations. Performa was filled by incorporating patients, family history of bleeding, signs & symptoms, and bleeding from any site. From them 144 individuals were screened with CBC, bleeding time, platelet aggregation studies & RiCoF. While for PT, APTT, VWF assay and Factor VIII assay, samples were kept frozen at -70 degrees C until tested.</p> <p>Results</p> <p>The family tree of the seven generations comprises of 533 individuals, 63 subjects died over a period of 20 years and 470 were alive. Out of all those 144 subjects were selected on the basis of the bleeding history. Among them 98(68.1%) were diagnosed to have a bleeding disorder; 44.9% patients were male and 55.1% patients were female. Median age of all the patients was 20.81, range (4 months- 80 yrs). The results of bleeding have shown that majority had gum bleeding, epistaxis and menorrhagia. Most common bleeding disorder was Von Willebrand disease and Platelet functional disorders.</p> <p>Conclusion</p> <p>Consanguineous marriages keep all the beneficial and adversely affecting recessive genes within the family; in homozygous states. These genes express themselves and result in life threatening diseases. Awareness, education & genetic counseling will be needed to prevent the spread of such common occurrence of these bleeding disorders in the community.</p
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