1,588 research outputs found

    Quality of Service Improvement in Femto based Cellular Networks

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    A cellular network serve the high service demands of the indoor users it is very expensive to obtain macrocell coverage which results in requirement of new methods to solve problem of high capacity indoor coverage femto cell is one of the solutions. Deployment of femto cell networks embedded into macro cell coverage improves the coverage, capacity and quality of service in indoor environments. Due to its ad-hoc nature, the information about its density and location is not known a-priori. As femtos and macros share the same licensed spectrum, interference is one of the major problems observed and has to be mitigated. In this paper two existing channel allocation schemes such as opportunistic channel allocation scheme and orthogonal channel allocation scheme are discussed and their performance is compared to the proposed Max-SINR scheme. To reduce the interference further a self-organized and intelligent resource allocation is also proposed .Parameter such as average SINR experienced by each femto user is calculated by varying the percentage of active Femto cells in a network. Simulation results are carryout using MATLAB

    Effective Stint Harmonisation For Mobile In Marine Sensor Networks

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    Deploy underwater sensors to record data during the monitoring mission, and then recover the instruments. This approach has the problems on Real time monitoring is not possible. No interaction is possible between onshore control systems and the monitoring instruments. Open nature of mobile marine sensor networks are indeed to communication of peers, however in these type of networks unmeasured and adapt to unpredictable environments .And spatial diversity and density of sensor/actuator nodes.So in this paper we are evalution of better solution for under ground  networks and eliminate malicious attacks of the mobile marines. Our experimental results are shows  efficacious and forcible for mobile mariens

    Sheltered Compound Vendor Data Apportioning For Vibrant Clusters In The Cloud

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    Cloud computing is an emerging computing paradigm in which resources of the computing infrastructure are provided as services over the Internet. Sharing data in a multiowner manner while preserving data and identity privacy from an untrusted cloud is still a challenging issue, due to the frequent change of the membership. To preserve data privacy, a basic solution is to encrypt data files, and then upload the encrypted data into the cloud. In this paper we are further extending the basic MONA by adding the reliability as well as improving the scalability by increasing the number of group managers dynamically. This paper proposes how user can access data after the time out. The storage overhead and encryption computation cost of our scheme are independent with the number of revoked users

    Addressing People and Place Microenvironments in Weight Loss Disparities (APP-Me): Design of a randomized controlled trial testing timely messages for weight loss behavior in low income black and white women

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    Background Behavioral interventions for weight loss have been less effective in lower income and black women. These poorer outcomes may in part be related to these women having more frequent exposures to social and physical situations that are obesogenic, i.e., eating and sedentary cues or situations. Objectives Working with obese, lower income black and white women, Addressing People and Place Microenvironments (APP-Me) was designed to create awareness of self-behavior at times and places of frequent eating and sedentary behavior. Design APP-Me is being evaluated in a randomized controlled trial with 240 participants recruited from federally qualified health centers located in a single Midwestern city. All participants complete four weeks of ecological momentary assessments (EMA) of situations and behavior. At the end of the four weeks, participants are randomized to enhanced usual care (UC) or UC plus APPMe. Methods APP-Me is an automated short messaging system (SMS). Messages are text, image, audio, or a combination, and are delivered to participants’ mobile devices with the intent of creating awareness at the times and places of frequent eating or sedentary behavior. The EMA data inform the timing of message deliveries. Summary This project aims to create and test timely awareness messages in a subpopulation that has not responded well to traditional behavioral interventions for weight loss. Novel aspects of the study include the involvement of a low income population, the use of data on time and place of obesogenic behavior, and message delivery time tailored to an individual’s behavioral patterns

    Antibacterial and antioxidant properties of the methanol extracts of the leaves and stems of Calpurnia aurea

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    <p>Abstract</p> <p>Background</p> <p>In South Africa, <it>Calpurnia aurea</it> (Ait.) Benth is used to destroy lice and to relieve itches, to destroy maggots and to treat allergic rashes, particularly those caused by caterpillars. Antioxidants play an important role protecting against damage by reactive oxygen species. Plants containing flavonoids have been reported to possess strong antioxidant properties.</p> <p>Methods</p> <p>The antibacterial, antioxidant activities and phenolic contents of the methanol extracts of the leaves and stems of <it>Calpurnia aurea</it> were evaluated using in vitro standard methods. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the stem extract of <it>Calpurnia aurea</it> were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP) methods. Laboratory isolates of 10 bacteria species which included five Gram-positive and five Gram-negative strains were used to assay for antibacterial activity of this plant.</p> <p>Results</p> <p>The results from this study showed that the antioxidant activities of the stem extract of <it>Calpurnia aurea </it>as determined by the total phenol, flavonoids, and FRAP methods were higher than that of the leaves. On the other hand, the leaf extract of the plant has higher level of total flavonols and proanthocyanidins. The leaf extract also has higher radical scavenging activity as shown in 1, 1-Diphenyl-2-picrylhydrazyl (DPPH), and 2,2Âż-azinobis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS) assay. The leaf extract showed activity against seven of the bacterial organisms.</p> <p>Conclusion</p> <p>The results from this study indicate that the leaves and stem extracts of <it>Calpurnia aurea </it>possess antioxidant properties and could serve as free radical inhibitors or scavenger or, acting possibly as primary antioxidants. Although, the antibacterial properties of <it>Calpurnia aurea</it> are not as effective as the standard drugs- Chloramphenicol and Streptomycin, they still possess some activity against bacterial strains used in this study. <it>Calpurnia aurea </it>may therefore be a good candidate for functional foods as well as pharmaceutical plant-based products.</p

    Continuous photodetection model: quantum jump engineering and hints for experimental verification

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    We examine some aspects of the continuous photodetection model for photocounting processes in cavities. First, we work out a microscopic model that describes the field-detector interaction and deduce a general expression for the Quantum Jump Superoperator (QJS), that shapes the detector's post-action on the field upon a detection. We show that in particular cases our model recovers the QJSs previously proposed ad hoc in the literature and point out that by adjusting the detector parameters one can engineer QJSs. Then we set up schemes for experimental verification of the model. By taking into account the ubiquitous non-idealities, we show that by measuring the lower photocounts moments and the mean waiting time one can check which QJS better describes the photocounting phenomenon.Comment: 12 pages, 7 figures. Contribution to the conference Quantum Optics III, Pucon - Chile, November 27-30, 200

    Multivalency in lectins-a crystallographic,modelling and light-scattering study involving peanut lectin and a bivalent ligand

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    Multivalency is believed to be important in the activity of lectins, although definitive structural studies on it have been few and far between. We have now studied the complexation of tetravalent peanut lectin with a synthetic compound containing two terminal lactose moieties, using a combination of crystallography, dynamic light scattering and modelling. Light scattering indicates the formation of an apparent dimeric species and also larger aggregates of the tetrameric lectin in the presence of the bivalent ligand. Crystals of presumably crosslinked lectin molecules could be obtained. They diffract poorly, but X-ray data from them are good enough to define the positions of the lectin molecules. Extensive modelling on possible crosslinking modes of protein molecules by the ligand indicated that systematic crosslinking could lead to crystalline arrays. The studies also provided a rationale for crosslinking in the observed crystal structure. The results obtained provide further insights into the general problem of multivalency in lectins. They indicate that crosslinking involving multivalent lectins and multivalent carbohydrates could lead to an ensemble of a finite number of distinct periodic arrays rather than a unique array

    Early and Late Reoperation Rates With Various MIS Techniques for Adult Spinal Deformity Correction.

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    Study designA multicenter retrospective review of an adult spinal deformity database.ObjectiveWe aimed to characterize reoperation rates and etiologies of adult spinal deformity surgery with circumferential minimally invasive surgery (cMIS) and hybrid (HYB) techniques.MethodsInclusion criteria were age ≥18 years, and one of the following: coronal Cobb &gt;20°, sagittal vertical axis &gt;5 cm, pelvic tilt &gt;20°, and pelvic incidence-lumbar lordosis &gt;10°. Patients with either cMIS or HYB surgery, ≥3 spinal levels treated with 2-year minimum follow-up were included.ResultsA total of 133 patients met inclusion for this study (65 HYB and 68 cMIS). Junctional failure (13.8%) was the most common reason for reoperation in the HYB group, while fixation failure was the most common reason in the cMIS group (14.7%). There was a higher incidence of proximal junctional failure (PJF) than distal junctional failure (DJF) within HYB (12.3% vs 3.1%), but no significant differences in PJF or DJF rates when compared to cMIS. Early (&lt;30 days) reoperations were less common (cMIS = 1.5%; HYB = 6.1%) than late (&gt;30 days) reoperations (cMIS = 26.5%; HYB = 27.7%), but early reoperations were more common in the HYB group after propensity matching, largely due to infection rates (10.8% vs 0%, P = .04).ConclusionsAdult spinal deformity correction with cMIS and HYB techniques result in overall reoperation rates of 27.9% and 33.8%, respectively, at minimum 2-year follow-up. Junctional failures are more common after HYB approaches, while pseudarthrosis/fixation failures happen more often with cMIS techniques. Early reoperations were less common than later returns to the operating room in both groups, but cMIS demonstrated less risk of infection and early reoperation when compared with the HYB group

    Isolation and Identification of Chlorate-Reducing Hafnia sp. From Milk

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    Chlorate has become a concern in the food and beverage sector, related to chlorine sanitizers in industrial food production and water treatment. It is of particular concern to regulatory bodies due to the negative health effects of chlorate exposure. This study investigated the fate of chlorate in raw milk and isolated bacterial strains of interest responsible for chlorate breakdown. Unpasteurized milk was demonstrated to have a chlorate-reducing capacity, breaking down enriched chlorate to undetectable levels in 11 days. Further enrichment and isolation using conditions specific to chlorate-reducing bacteria successfully isolated three distinct strains of Hafnia paralvei . Chlorate-reducing bacteria were observed to grow in a chlorate-enriched medium with lactate as an electron donor. All isolated strains were demonstrated to reduce chlorate in liquid medium; however, the exact mechanism of chlorate degradation was not definitively identified in this study
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