98 research outputs found

    An Efficient Rerouting Approach in Software Defined Networks

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    This paper illustrates an efficient traffic rerouting solution in Software-Defined Networks (SDN) by monitoring the network status periodically. The proposed approach provides a rerouting solution by first calculating the link utilization for available paths and then rerouting the flow to the least delay path among the available paths. The traffic rerouting solution is considering the network condition to prevent the switch overutilization and congestion while any new flow arrives. The proposed method is implemented by using ONOS controller and Mininet emulator. The proposed algorithm in the controller predicts the utilization and delay on the link to calculate how much load to be rerouted if the average link utilization exceeds the threshold level. Hence, this method will proactively avoid congestion by adding flows, monitoring the parameters and prevent the unbalanced distribution after rerouting as our experimental results show

    Development of a technology adoption and usage prediction tool for assistive technology for people with dementia

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    This article is available open access through the publisher’s website at the link below. Copyright @ The Authors 2013.In the current work, data gleaned from an assistive technology (reminding technology), which has been evaluated with people with Dementia over a period of several years was retrospectively studied to extract the factors that contributed to successful adoption. The aim was to develop a prediction model with the capability of prospectively assessing whether the assistive technology would be suitable for persons with Dementia (and their carer), based on user characteristics, needs and perceptions. Such a prediction tool has the ability to empower a formal carer to assess, through a very limited amount of questions, whether the technology will be adopted and used.EPSR

    A SDN-based On-Demand Path Provisioning Approach across Multi-domain Optical Networks

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    The interconnection of remote datacentres with optical networks are emerging use cases and such orchestration of multi-domains require the design of new network control, management, and orchestration architectures. Such heterogeneity needs to adopt end-to-end services like on-demand path provisioning. It is acknowledged that such scenarios are more complexed and have fundamental limitations in terms of high performance and delay. To address these issues, and as a means to cope with the complexity growth, research in this area is considering the concept of Software-Defined Network (SDN) orchestration for multi-domain optical networks to coordinated the control of heterogeneous systems. This paper presents a SDN path provisioning approach across Multi-Domain Optical Networks. The aim is to develop an efficient on-demand path provisioning platform in a software defined optical network at the control plane to dynamically manage the network's load, especially in emergency scenarios. The proposed distributed system architecture will help to solve the longstanding problem of inter-domain path provisioning. Our proposed architecture is implemented and validated in a control plane testbed to validate the approach. The paper also evaluated the factors such Quality of Service (QoS) of the network deployment associated with delay or control overhead. Our results show that the method will reduce additional delays in a multi-domain optical network, where high capacity and low latency are requirements for data-intensive applications and cloud services. The proposed method also maintains the total number of flows as low as possible to make the algorithm fast and reduce overheads

    Saskatchewan Northern Health Authorities, Saskatchewan Correspondence and reprints: Dr James Irvine, Population Health Unit, Athabasca Health Authority, Keewatin Yatthé Health Region and Mamawetan Churchill River Health Region, Box 6000, LaRonge, Saskatch

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    A 51-year-old Aboriginal woman from northern Saskatchewan presented to a local family medical clinic in early October 2006 with a three-day history of left knee pain. Her vital signs included a blood pressure of 114/70 mmHg, a heart rate of 100 beats/min and a respiratory rate of 20 breaths/min. Her temperature was not documented. On examination, her knee was warm and painful, and an effusion was noted. Approximately six weeks prior, she had fallen on her right knee while walking. This injury was complicated by hemarthrosis and effusion, requiring needle drainage on two occasions. In addition, she had a history of pain, swelling and erythema involving her shoulder joint. Her past history was significant for alcohol abuse and unstable social and housing conditions. The laboratory results showed the followingwhite blood cell (WBC) count 9.8×10 9 /L (normal 0.2×10 9 /L to 10×10 9 /L); granulocyte count 8.8×10 9 /L (normal 2×10 9 /L to 7.8×10 9 /L); hemoglobin (Hb) level 102 g/L (normal 120 g/L to 180 g/L) and platelet count 68×10 9 /L (normal 150×10 9 /L to 450×10 9 /L). A presumptive diagnosis of inflammatory arthritis was made, and she was given indomethacin 50 mg three times a day for her symptoms. Two days later, the patient became progressively more confused, disoriented and unresponsive to questions. She was brought by ambulance to the local emergency department where her temperature was 38.8°C, pulse 98 beats/min, blood pressure 140/83 mmHg and respiratory rate 32 breaths/min. Her Glasgow coma scale score was 6. She was unresponsive to verbal commands but responsive to painful stimuli. Bruising was noted on both legs, and a large area of erythema was noted around the left knee. Her respiratory examination was unremarkable. Laboratory results showed the following -WBC count 3. 135 U/L) and creatine kinase isoenzyme -MB level 28 U/L (normal 0 U/L to 16 U/L). An evolving neurological condition was thought to be the primary diagnosis. Initial management included intravenous fluid (200 mL/h), cefotaxime 2 g administered intravenously, and blood cultures. She was transferred by air to the Royal University Hospital in Saskatoon, Saskatchewan. During the 1 h flight to Saskatoon, the area of erythema on her left leg tripled in size, and 3 L of intravenous fluids and dopamine were required to stabilize her blood pressure. On arrival, she was noted to be diffusely rigid with no response to painful stimuli. Her temperature was 39°C. She had rigors, peripheral mottling, absence of peripheral pulses, bronchial breath sounds over the right middle lobe, and erythema and target-like lesions over her left knee. Laboratory evaluation on admission showed the following -WBC count 3.

    Gac two-component system in Pseudomonas syringae pv. tabaci is required for virulence but not for hypersensitive reaction

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    Pseudomonas syringae pv. tabaci 6605 causes wildfire disease on host tobacco plants. To investigate the regulatory mechanism of the expression of virulence, Gac two-Component system-defective mutants, Delta gacA and Delta gacS, and a double mutant, Delta gacA Delta gacS, were generated. These mutants produced smaller amounts of N-acyl homoserine lactones required for quorum sensing, had lost swarming motility, and had reduced expression of virulence-related hrp genes and the algT gene required for exopolysaccharide production. The ability of the mutants to cause disease symptoms in their host tobacco plant was remarkably reduced, while they retained the ability to induce hypersensitive reaction (HR) in the nonhost plants. These results indicated that the Gac two-component system of P. syringae pv. tabaci 6605 is indispensable for virulence on the host plant, but not for HR induction in the nonhost plants.</p

    ‘Test n Treat (TnT)’: a cluster-randomised feasibility trial of frequent, rapid-testing and same-day, on-site treatment to reduce rates of chlamydia in high-risk further education college students: statistical analysis plan

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    Background There are high rates of sexually transmitted infections (STIs) in ethnically diverse, sexually active students aged 16–24 years attending London further education (FE) colleges. However, uptake of chlamydia screening remains low. The TnT study aims to assess the feasibility of conducting a future trial in FE colleges to investigate if frequent, rapid, on-site testing and treatment (TnT) reduces chlamydia rates. This article presents the statistical analysis plan for the main study publication as approved and signed off by the Trial Management Group prior to the first data extraction for the final report. Methods/design TnT is a cluster-randomised feasibility trial conducted over 7 months with parallel qualitative and economic assessments. Colleges will be randomly allocated into the intervention (TnT) or the control group (no TnT). Six FE colleges in London will be included. At each college for 2 days, 80 consecutive sexually active students aged 16–24 years (total 480 students across all six colleges) will be recruited from public areas and asked to provide baseline samples. One and 4 months after recruitment intervention colleges will be visited on two consecutive days by the TnT team where participating students will be texted and invited to come for same-day, on-site, rapid chlamydia testing and, if positive, treatment. Participants in the control colleges will receive ‘thank you’ texts 1 and 4 months after recruitment. Seven months after recruitment, participants from both groups will be invited to complete questionnaires and provide samples for TnT. All samples will be tested, and same-day treatment offered to participants with positive results. Key feasibility outcomes include: recruitment rates, testing and treatment uptake rates (at 1 and 4 months) and follow-up rates (at 7 months). Trial registration ISRCTN 58038795. Registered on 31 August 2016

    Definition of strategies for the reduction of operational inefficiencies in a stroke unit

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    Stroke disease is the second common cause of death in the world and is then of particular concern to policy-makers. Additionally, it is a meaningful problem leaving a high number of people with severe disabilities, placing a heavy burden on society and incurring prolonged length of stay. In this respect, it is necessary to develop analytic models providing information on care system behavior in order to detect potential operational inefficiencies along the stroke patient journey and subsequently design improvement strategies. However, modeling stroke care is highly complex due to the multiple clinical outcomes and different pathways. Therefore, this paper presents an integrated approach between Discrete-event Simulation (DES) and Markov models so that integrated planning of healthcare services relating to stroke care and the evaluation of potential improvement scenarios can be facilitated, made more logically robust and easy to understand. First, a stroke care system from Colombia was characterized by identifying the exogenous and endogenous variables of the process. Afterward, an input analysis was conducted to define the probability distributions of the aforementioned variables. Then, both DES and Markov models were designed and validated to provide deeper analysis of the entire patient journey. Finally, the possible adoption of thrombolytic treatment on patients with stroke disease was assessed based on the proposed approaches within this paper. The results evidenced that the length of stay (LOS) decreased by 12,89% and the mortality ratio was diminished by 21,52%. Evaluation of treatment cost per patient is also carried out

    Drosophila melanogaster as a Model Host for the Burkholderia cepacia Complex

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    Colonization with bacterial species from the Burkholderia cepacia complex (Bcc) is associated with fast health decline among individuals with cystic fibrosis. In order to investigate the virulence of the Bcc, several alternative infection models have been developed. To this end, the fruit fly is increasingly used as surrogate host, and its validity to enhance our understanding of host-pathogen relationships has been demonstrated with a variety of microorganisms. Moreover, its relevance as a suitable alternative to mammalian hosts has been confirmed with vertebrate organisms.The aim of this study was to establish Drosophila melanogaster as a surrogate host for species from the Bcc. While the feeding method proved unsuccessful at killing the flies, the pricking technique did generate mortality within the populations. Results obtained with the fruit fly model are comparable with results obtained using mammalian infection models. Furthermore, validity of the Drosophila infection model was confirmed with B. cenocepacia K56-2 mutants known to be less virulent in murine hosts or in other alternative models. Competitive index (CI) analyses were also performed using the fruit fly as host. Results of CI experiments agree with those obtained with mammalian models.We conclude that Drosophila is a useful alternative infection model for Bcc and that fly pricking assays and competition indices are two complementary methods for virulence testing. Moreover, CI results indicate that this method is more sensitive than mortality tests
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