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Sample records for concurrent zidovudine levels

  1. Zidovudine disposition during hemodialysis in a patient with acquired immunodeficiency syndrome.

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    Tartaglione, T A; Holeman, E; Opheim, K; Smith, T; Collier, A C

    1990-01-01

    Zidovudine (azidothymidine, AZT) disposition was examined during a hemodialysis session in an HIV-infected male with mesangial proliferative glomerulonephritis. Serum concentrations of zidovudine and its glucuronidated inactive metabolite (G-ZDV) were measured by HPLC. Zidovudine pharmacokinetics were similar to previous reports in patients with normal renal function, however, G-ZDV concentrations were significantly elevated (23-440 times zidovudine concentration). Hemodialysis did not appreciably reduce zidovudine or G-ZDV levels. Significance of chronically elevated G-ZDV levels is unknown.

  2. Zidovudine-induced myopathy: A study in Indian patients

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    Amitabh Sagar

    2010-01-01

    Full Text Available Context: Literature is replete with studies on zidovudine-induced myopathy after prolonged use (use beyond 270 days on an average. However, all these studies have been done on patients of Caucasian, American and African ethnic origin. No such study has been carried out in Indian patients to our knowledge. Aims: To determine the correlation of zidovudine usage with serum creatine phosphokinase (CK levels, clinical muscular weakness and muscle histology in Indian patients, we studied 147 physically active, Human Immunodeficiency Virus infected men on prolonged zidovudine-based antiretroviral therapy (ART. Settings and Design: Cross-sectional study on hospital follow-up patients of HIV infection. Materials and Methods: All cases on ART who reported to our canter during a period of 18 months were evaluated for symptoms (muscle fatigue, myalgia, objective muscle strength (testing clinically and serum CK levels, and a select group was evaluated by muscle biopsy. These patients were on zidovudine for 1 to 7 years. Results: None of the patients studied had significant symptoms or objective muscle weakness and only a small fraction (10.8% of cases had marginally raised serum CK levels. All muscle biopsies were normal on light microscopy. Conclusions: Zidovudine myopathy may be a constraint for use of the drug in the western population; however, it is a well-tolerated drug as regards myopathy in our study on Indian patients.

  3. Higher levels of Zidovudine resistant HIV in the colon compared to blood and other gastrointestinal compartments in HIV infection

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    van Marle Guido

    2010-09-01

    Full Text Available Abstract Background The gut-associated lymphoid tissue (GALT is the largest lymphoid organ infected by human immunodeficiency virus type 1 (HIV-1. It serves as a viral reservoir and host-pathogen interface in infection. This study examined whether different parts of the gut and peripheral blood lymphocytes (PBL contain different drug-resistant HIV-1 variants. Methods Gut biopsies (esophagus, stomach, duodenum and colon and PBL were obtained from 8 HIV-1 infected preHAART (highly active antiretroviral therapy patients at three visits over 18 months. Patients received AZT, ddI or combinations of AZT/ddI. HIV-1 Reverse transcriptase (RT-coding sequences were amplified from viral DNA obtained from gut tissues and PBL, using nested PCR. The PCR fragments were cloned and sequenced. The resulting sequences were subjected to phylogenetic analyses, and antiretroviral drug mutations were identified. Results Phylogenetic and drug mutation analyses revealed differential distribution of drug resistant mutations in the gut within patients. The level of drug-resistance conferred by the RT sequences was significantly different between different gut tissues and PBL, and varied with antiretroviral therapy. The sequences conferring the highest level of drug-resistance to AZT were found in the colon. Conclusion This study confirms that different drug-resistant HIV-1 variants are present in different gut tissues, and it is the first report to document that particular gut tissues may select for drug resistant HIV-1 variants.

  4. Task-Level Data Model for Hardware Synthesis Based on Concurrent Collections

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    Jason Cong

    2012-01-01

    Full Text Available The ever-increasing design complexity of modern digital systems makes it necessary to develop electronic system-level (ESL methodologies with automation and optimization in the higher abstraction level. How the concurrency is modeled in the application specification plays a significant role in ESL design frameworks. The state-of-art concurrent specification models are not suitable for modeling task-level concurrent behavior for the hardware synthesis design flow. Based on the concurrent collection (CnC model, which provides the maximum freedom of task rescheduling, we propose task-level data model (TLDM, targeted at the task-level optimization in hardware synthesis for data processing applications. Polyhedral models are embedded in TLDM for concise expression of task instances, array accesses, and dependencies. Examples are shown to illustrate the advantages of our TLDM specification compared to other widely used concurrency specifications.

  5. Mycorrhization level in truffle plants and presence of concurrent fungi

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    Leonardo B. Falini

    2013-12-01

    Full Text Available In Italy, to improve good practices for truffle cultivation, some regional governments require specific certification of mycorrhization level and plant quality for marketing, out-planting and establishment of truffle orchards. The Department of Applied Biology at the University of Perugia has dealt with certification of truffle plants since the 1980’s. Here we show the mycorrhization analysis of different host species previously inoculated with truffle spores by an Italian commercial nursery.

  6. Integrated System-Level Optimization for Concurrent Engineering With Parametric Subsystem Modeling

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    Schuman, Todd; DeWeck, Oliver L.; Sobieski, Jaroslaw

    2005-01-01

    The introduction of concurrent design practices to the aerospace industry has greatly increased the productivity of engineers and teams during design sessions as demonstrated by JPL's Team X. Simultaneously, advances in computing power have given rise to a host of potent numerical optimization methods capable of solving complex multidisciplinary optimization problems containing hundreds of variables, constraints, and governing equations. Unfortunately, such methods are tedious to set up and require significant amounts of time and processor power to execute, thus making them unsuitable for rapid concurrent engineering use. This paper proposes a framework for Integration of System-Level Optimization with Concurrent Engineering (ISLOCE). It uses parametric neural-network approximations of the subsystem models. These approximations are then linked to a system-level optimizer that is capable of reaching a solution quickly due to the reduced complexity of the approximations. The integration structure is described in detail and applied to the multiobjective design of a simplified Space Shuttle external fuel tank model. Further, a comparison is made between the new framework and traditional concurrent engineering (without system optimization) through an experimental trial with two groups of engineers. Each method is evaluated in terms of optimizer accuracy, time to solution, and ease of use. The results suggest that system-level optimization, running as a background process during integrated concurrent engineering sessions, is potentially advantageous as long as it is judiciously implemented.

  7. Zidovudine/lamivudine for HIV-1 infection contributes to limb fat loss.

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    Marit G A van Vonderen

    Full Text Available BACKGROUND: Lipoatrophy is known to be associated with stavudine as part of the treatment for HIV infection, but it is less clear if this serious side effect is also related to other nucleoside reverse transcriptase inhibitors like zidovudine. We aimed to determine whether zidovudine-sparing first-line antiretroviral therapy would lead to less lipoatrophy and other metabolic changes than zidovudine-containing therapy. METHODOLOGY/PRINCIPAL FINDINGS: Fifty antiretroviral therapy-naïve HIV-1 infected men with an indication to start antiretroviral therapy were included in a randomized single blinded clinical trial. Randomisation was between zidovudine-containing therapy (zidovudine/lamivudine+lopinavir/ritonavir and zidovudine-sparing therapy (nevirapine+lopinavir/ritonavir. Main outcome measures were body composition assessed by computed tomography and dual-energy X-ray absorptiometry scan and lipid profile before and after 3, 12, 24 months of antiretroviral therapy. In the zidovudine/lamivudine+lopinavir/ritonavir group, from 3 months onward limb fat decreased progressively by 684+/-293 grams (estimated mean+/-standard error of the mean(p = 0.02 up to 24 months whereas abdominal fat increased, but exclusively in the visceral compartment (+21.9+/-8.1 cm(2, p = 0.008. In contrast, in the nevirapine+lopinavir/ritonavir group, a generalized increase in fat mass was observed. After 24 months no significant differences in high density lipoprotein and total/high density lipoprotein cholesterol ratio were found between both treatment groups, but total and low density lipoprotein cholesterol levels were higher in the nevirapine+lopinavir/ritonavir group (6.1+/-0.2 versus 5.3+/-0.2 and 3.6+/-0.1 versus 2.8+/-0.1 mmol/l respectively, p<0.05. Virologic response and safety were comparable in both groups. CONCLUSIONS/SIGNIFICANCE: Zidovudine/lamivudine+lopinavir/ritonavir, but not nevirapine+lopinavir/ritonavir in antiretroviral therapy-naïve patients, is

  8. On-demand thread-level fault detection in a concurrent programming environment

    NARCIS (Netherlands)

    Fu, J.; Yang, Q.; Poss, R.; Jesshope, C.R.; Zhang, C.; Jeschke, H.; Silvén, O.

    2013-01-01

    The vulnerability of multi-core processors is increasing due to tighter design margins and greater susceptibility to interference. Moreover, concurrent programming environments are the norm in the exploitation of multi-core systems. In this paper, we present an on-demand thread-level fault detection

  9. Concurrent Validity of the Independent Reading Level Assessment Framework and a State Assessment

    Science.gov (United States)

    Ralston, Nicole C.; Waggoner, Jacqueline M.; Tarasawa, Beth; Jackson, Amy

    2016-01-01

    This study investigates the use of screening assessments within the increasingly popular Response to Intervention (RTI) framework, specifically seeking to collect concurrent validity evidence on one potential new screening tool, the Independent Reading Level Assessment (IRLA) framework. Furthermore, this study builds on existing literature by…

  10. On-demand thread-level fault detection in a concurrent programming environment

    NARCIS (Netherlands)

    Fu, J.; Yang, Q.; Poss, R.; Jesshope, C.R.; Zhang, C.; Jeschke, H.; Silvén, O.

    2013-01-01

    The vulnerability of multi-core processors is increasing due to tighter design margins and greater susceptibility to interference. Moreover, concurrent programming environments are the norm in the exploitation of multi-core systems. In this paper, we present an on-demand thread-level fault detection

  11. SPRINT: A Tool to Generate Concurrent Transaction-Level Models from Sequential Code

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    Cockx Johan

    2007-01-01

    Full Text Available A high-level concurrent model such as a SystemC transaction-level model can provide early feedback during the exploration of implementation alternatives for state-of-the-art signal processing applications like video codecs on a multiprocessor platform. However, the creation of such a model starting from sequential code is a time-consuming and error-prone task. It is typically done only once, if at all, for a given design. This lack of exploration of the design space often leads to a suboptimal implementation. To support our systematic C-based design flow, we have developed a tool to generate a concurrent SystemC transaction-level model for user-selected task boundaries. Using this tool, different parallelization alternatives have been evaluated during the design of an MPEG-4 simple profile encoder and an embedded zero-tree coder. Generation plus evaluation of an alternative was possible in less than six minutes. This is fast enough to allow extensive exploration of the design space.

  12. SPRINT: A Tool to Generate Concurrent Transaction-Level Models from Sequential Code

    Directory of Open Access Journals (Sweden)

    Richard Stahl

    2007-01-01

    Full Text Available A high-level concurrent model such as a SystemC transaction-level model can provide early feedback during the exploration of implementation alternatives for state-of-the-art signal processing applications like video codecs on a multiprocessor platform. However, the creation of such a model starting from sequential code is a time-consuming and error-prone task. It is typically done only once, if at all, for a given design. This lack of exploration of the design space often leads to a suboptimal implementation. To support our systematic C-based design flow, we have developed a tool to generate a concurrent SystemC transaction-level model for user-selected task boundaries. Using this tool, different parallelization alternatives have been evaluated during the design of an MPEG-4 simple profile encoder and an embedded zero-tree coder. Generation plus evaluation of an alternative was possible in less than six minutes. This is fast enough to allow extensive exploration of the design space.

  13. Hepatoprotective role of neutrosecR on hepatic damage induced by combination of zidovudine and combined anti-tuberculous agents in rats.

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    Awodele, Olufunsho; Agbaje, Esther O; Adesina, Enitan A; Akintonwa, Alade

    2011-07-20

    Advent of the HIV/AIDS pandemic has led to a dramatic increase in the number of TB cases worldwide. Availability of highly active antiretroviral therapy (HAART) has significantly improved the outcome of HIV/AIDS, in terms of prevention of opportunistic infections (OIs) as well as mortality however; liver toxicity is one of the most relevant adverse effects of antiretroviral therapy (ART). In view of the inevitable use of zidovudine (a common ART) and antituberculous fixed-dose combination therapy (FDCs) in the management of HIV-TB co-infection and the resultant hepatotoxicity, this study was aimed to investigate the hepatoprotective role of neutrosec (a combination of aminoacid and vitamins) on the hepatotoxicity induced by co-administration of zidovudine and combined fixed dose antituberculous agents. Twenty four rats were randomly allotted to four groups, consisting of the control, zidovudine plus fixed dose combined anti TB agents treated group, zidovudine plus fixed dose combined anti TB agents plus neutrosec treated group and neutrosec alone treated group. Therapeutic doses of zidovudine (8.5 mg/kg/day), fixed dose combined anti TB agents (25 mg/kg/day) and neutrosec (0.4 ml/kg/day) were administered to the animals via oral gavage, daily over 60 days. After 60 days, rats were sacrificed for internal macroscopic and histological examination of the liver. The liver enzyme parameters (AST, ALP, Total bilirubin, Total protein, Albumin) were determined using fully automated clinical chemistry analyzer (Hitachi 912, Boehringer Mannheim, Germany). Antioxidant enzymes activity and lipid peroxidation were determined according to standard procedures. The AST results showed a significant (p ≤ 0.05) decreased in the zidovudine plus anti-TB plus neutrosec treated group (125.50 ± 22.71) compared with zidovudine plus anti-TB treated group (399. 10 ± 0.45). It further showed non-significant decreased (p ≥ 0.05) in the ALP levels between the zidovudine plus anti TB

  14. Mitochondrial myopathy caused by long-term zidovudine therapy.

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    Dalakas, M C; Illa, I; Pezeshkpour, G H; Laukaitis, J P; Cohen, B; Griffin, J L

    1990-04-19

    Both infection with the human immunodeficiency virus type 1 (HIV) and zidovudine (formerly called azidothymidine [AZT]) cause myopathy. To identify criteria for distinguishing zidovudine-induced myopathy from that caused by primary HIV infection, we reviewed the histochemical, immunocytochemical, and electron-microscopical features of muscle-biopsy specimens from 20 HIV-positive patients with myopathy (15 of whom had been treated with zidovudine) and compared the findings with the patients' clinical course and response to various therapies. Among the zidovudine-treated patients, the myopathy responded to prednisone in four, to the discontinuation of zidovudine in eight, and to nonsteroidal anti-inflammatory drugs in two. Numerous "ragged-red" fibers, indicative of abnormal mitochondria with paracrystalline inclusions, were found in the biopsy specimens from the zidovudine-treated patients but not in those from the other patients. The number of these fibers appeared to correlate with the severity of the myopathy. All the patients, regardless of whether they had been treated with zidovudine, had inflammatory myopathy characterized by degenerating fibers, cytoplasmic bodies, and endomysial infiltrates consisting of CD8+ cells (mean +/- SD, 60.7 +/- 6.4 percent) and macrophages (39.2 +/- 6.4 percent) associated with Class I major histocompatibility complex (MHC-I) antigens (HLA-A, -B, and -C antigens) in the muscle fibers. The numbers and percentages of CD8+ cells and macrophages were similar in both the zidovudine-treated and the untreated HIV-positive patients. Specimens obtained on repeat muscle biopsy from two patients in whom the myopathy responded to the discontinuation of zidovudine showed remarkable histologic improvement. We conclude that long-term therapy with zidovudine can cause a toxic mitochondrial myopathy, which coexists with a T-cell-mediated inflammatory myopathy that is restricted to MHC-I antigen, and is indistinguishable from the myopathy

  15. morphological effects of chronic administration of zidovudine on the ...

    African Journals Online (AJOL)

    BRIAN

    OF ZIDOVUDINE ON THE VISUAL RELAY CENTRES OF ADULT. WISTAR RATS ... ABSTRACT. The oxidative stress effects in ... The toxic effects of ZDV on the morphology of the intracranial visual relay centres of the tested adult wistar rats ...

  16. Concurrent Collections

    OpenAIRE

    Zoran Budimlić; Michael Burke; Vincent Cavé; Kathleen Knobe; Geoff Lowney; Ryan Newton; Jens Palsberg; David Peixotto; Vivek Sarkar; Frank Schlimbach; Sağnak Taşırlar

    2010-01-01

    We introduce the Concurrent Collections (CnC) programming model. CnC supports flexible combinations of task and data parallelism while retaining determinism. CnC is implicitly parallel, with the user providing high-level operations along with semantic ordering constraints that together form a CnC graph. We formally describe the execution semantics of CnC and prove that the model guarantees deterministic computation. We evaluate the performance of CnC implementations on several applications an...

  17. Concurrent Collections

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    Zoran Budimlić

    2010-01-01

    Full Text Available We introduce the Concurrent Collections (CnC programming model. CnC supports flexible combinations of task and data parallelism while retaining determinism. CnC is implicitly parallel, with the user providing high-level operations along with semantic ordering constraints that together form a CnC graph. We formally describe the execution semantics of CnC and prove that the model guarantees deterministic computation. We evaluate the performance of CnC implementations on several applications and show that CnC offers performance and scalability equivalent to or better than that offered by lower-level parallel programming models.

  18. Development of severe anaemia and changes in Haemoglobin (Hb) in a cohort of HIV infected Ugandan Adults receiving Zidovudine, Stavudine and Tenofovir containing antiretroviral regimens

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    Parkes-Ratanshi, Rosalind; Katende, David; Levin, Jonathan; Wakeham, Katie; Heiner, Grosskurth; Kamali, Anatoli; Lalloo, David G

    2016-01-01

    Introduction Anaemia is a common problem in HIV in sub-Saharan Africa. We describe the contribution of ART regimen on the incidence of anaemia and changes in haemoglobin in Ugandan patients. Methods This study was nested in a prevention of cryptococcal disease trial (CRYPTOPRO; ISCRTN7648152). Patients received three different nucleoside reverse transcriptase inhibitor backbones in a non-randomised manner. Results Of 852 patients (161 on zidovudine, 628 on stavudine and 63 on tenofovir (all received lamuvidine), the risk of developing grade 4 anaemia was higher (aHR 2.7) for those taking zidovudine compared with stavudine. Those taking stavudine had a greater average increase in haemoglobin than those taking zidovudine (p=0.024) or tenofovir (p=0.014). Conclusion In this observational study zidovudine was associated with higher levels of severe anaemia than stavudine or tenofovir; those receiving zidovudine and tenofovir had smaller haemoglobin rises after ART initiation. We encourage publication of data from African cohorts using tenofovir. PMID:25425638

  19. Zidovudine treatment of AIDS and ARC in Denmark 1987

    DEFF Research Database (Denmark)

    Teglbjærg, Lars Stubbe; Mathiesen, L R; Søeberg, B;

    1989-01-01

    In 1987, a total of 138 Danish patients (94 AIDS and 44 ARC) received treatment with zidovudine, a total observation period of 572 treatment months. 15 AIDS and 1 ARC patient died after a median of 70 days (range 2-295). In the ARC group 4 patients developed AIDS (3 Pneumocystis carinii pneumonia......, 1 Kaposi's sarcoma). Among the AIDS patients 38 new opportunistic infections were reported. 24 of these opportunistic infections occurred within 6 weeks after treatment initiation. 79 patients were observed for more than 3 months, 25 of these had their daily dose zidovudine reduced, usually from 1...... on 94 occasions and 19 (14%) patients required multiple transfusions. The mortality among the AIDS patients was significantly lower compared to historical controls. In our experience zidovudine treatment is reasonably well tolerated and the side effects are manageable....

  20. Zidovudine treatment of AIDS and ARC in Denmark 1987

    DEFF Research Database (Denmark)

    Teglbjaerg, L L; Mathiesen, Lars Reinhardt; Søeberg, B;

    1989-01-01

    ,200 mg to 600 mg, 9 others were temporarily off drug. HIV antigen was analyzed in serum samples from 93 patients. Of these, 28 (52%) of 54 initially HIV antigen-positive became antigen-negative, 7 (18%) of 39 initially HIV antigen-negative became antigen-positive within the first 8 weeks of zidovudine......In 1987, a total of 138 Danish patients (94 AIDS and 44 ARC) received treatment with zidovudine, a total observation period of 572 treatment months. 15 AIDS and 1 ARC patient died after a median of 70 days (range 2-295). In the ARC group 4 patients developed AIDS (3 Pneumocystis carinii pneumonia......, 1 Kaposi's sarcoma). Among the AIDS patients 38 new opportunistic infections were reported. 24 of these opportunistic infections occurred within 6 weeks after treatment initiation. 79 patients were observed for more than 3 months, 25 of these had their daily dose zidovudine reduced, usually from 1...

  1. Measuring and modelling concurrency

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    Larry Sawers

    2013-02-01

    Full Text Available This article explores three critical topics discussed in the recent debate over concurrency (overlapping sexual partnerships: measurement of the prevalence of concurrency, mathematical modelling of concurrency and HIV epidemic dynamics, and measuring the correlation between HIV and concurrency. The focus of the article is the concurrency hypothesis – the proposition that presumed high prevalence of concurrency explains sub-Saharan Africa's exceptionally high HIV prevalence. Recent surveys using improved questionnaire design show reported concurrency ranging from 0.8% to 7.6% in the region. Even after adjusting for plausible levels of reporting errors, appropriately parameterized sexual network models of HIV epidemics do not generate sustainable epidemic trajectories (avoid epidemic extinction at levels of concurrency found in recent surveys in sub-Saharan Africa. Efforts to support the concurrency hypothesis with a statistical correlation between HIV incidence and concurrency prevalence are not yet successful. Two decades of efforts to find evidence in support of the concurrency hypothesis have failed to build a convincing case.

  2. Pharmacokinetic and Tissue Distribution Study of Solid Lipid Nanoparticles of Zidovudine in Rats

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    Shah Purvin

    2014-01-01

    Full Text Available Zidovudine-loaded solid lipid nanoparticles (AZT-SLNs and zidovudine in solution were prepared and administered in rats. The aim of this research was to study whether the bioavailability of zidovudine can be improved by AZT-SLNs perorally to rats as compared to oral administration of zidovudine. Zidovudine was determined in plasma and tissues by reverse phase high performance liquid chromatography. The pharmacokinetic parameters of zidovudine were determined after peroral administration: area under curve of concentration versus time (AUC for AZT-SLNs was 31.25% greater than AZT solution; meanwhile mean resident time (MRT was found to be 1.83 times higher for AZT-SLNs than AZT solution. Elimination half life of zidovudine was also increased for SLN formulation. Tissue distribution pattern of zidovudine was changed in case of AZT-SLNs. AUC of zidovudine in brain and liver was found to be approximately 2.73 and 1.77 times higher in AZT-SLNs than AZT solution, respectively, indicating that AZT-SLNs could cross blood brain barrier. Distribution of zidovudine was approximately 0.95 and 0.86 times lesser in heart and kidney, respectively. It can be concluded from the study that oral administration of AZT-SLNs modifies the plasma pharmacokinetic parameters and biodistribution of zidovudine.

  3. The PVM (Parallel Virtual Machine) system: Supercomputer level concurrent computation on a network of IBM RS/6000 power stations

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    Sunderam, V.S. (Emory Univ., Atlanta, GA (USA). Dept. of Mathematics and Computer Science); Geist, G.A. (Oak Ridge National Lab., TN (USA))

    1991-01-01

    The PVM (Parallel Virtual Machine) system enables supercomputer level concurrent computations to be performed on interconnected networks of heterogeneous computer systems. Specifically, a network of 13 IBM RS/6000 powerstations has been successfully used to execute production quality runs of superconductor modeling codes at more than 250 Mflops. This work demonstrates the effectiveness of cooperative concurrent processing for high performance applications, and shows that supercomputer level computations may be attained at a fraction of the cost on distributed computing platforms. This paper describes the PVM programming environment and user facilities, as they apply to hardware platforms comprising a network of IBM RS/6000 powerstations. The salient design features of PVM will be discussed; including heterogeneity, scalability, multilanguage support, provisions for fault tolerance, the use of multiprocessors and scalar machines, an interactive graphical front end, and support for profiling, tracing, and visual analysis. The PVM system has been used extensively, and a range of production quality concurrent applications have been successfully executed using PVM on a variety of networked platforms. The paper will mention representative examples, and discuss two in detail. The first is a material sciences problem that was originally developed on a Cray 2. This application code calculates the electronic structure of metallic alloys from first principles and is based on the KKR-CPA algorithm. The second is a molecular dynamics simulation for calculating materials properties. Performance results for both applicants on networks of RS/6000 powerstations will be presented, and accompanied by discussions of the other advantages of PVM and its potential as a complement or alternative to conventional supercomputers.

  4. Formulation and Release Characteristics of Zidovudine-Loaded ...

    African Journals Online (AJOL)

    Methods: Different concentrations (0, 1, 2, 3 and 5 %w/w) of zidovudine (AZT) were ... Particle size analysis indicated that the particles were irregular in shape with size ... Keywords: Phospholipon® 90H, Solidified lipid microparticles, Solidified ...

  5. [Rapid development of anemia in a HIV-positive patient with alpha-thalassemia after zidovudine therapy].

    Science.gov (United States)

    Altinbaş, Akif; Ozkaya, Gülşen; Büyükaşik, Yahya; Unal, Serhat

    2007-07-01

    Anemia, which may develop due to direct effect of the virus or indirect effect of zidovudine a widely used antiviral agent for the treatment, is not an uncommon complication in human immundeficiency virus (HIV) infections. In this report, a 26 years old male HIV positive patient who developed rapid anemia in the HAART (Highly active anti-retroviral therapy) protocol including zidovudine, was presented. The patient has been followed since May 2003 without anti-retroviral therapy. He was diagnosed as alpha-thalassemia trait, because of the low mean red blood cell volume (MCV), high red blood cell count and living in an Mediterranian country. However, no treatment for thalassemia had been given in this period, since the other laboratory findings [hemoglobin, hematocrit, red cell distribution width index (RDWI), iron and iron binding capacity, transferrin saturation and ferritin levels] were normal. During the follow-up of patient, HAART protocol with zidovudine, lamivudine and indinavir, was started depending on the findings of low CD4+ T-cell count (443/mm3) and high HIV serum load (1,330,000 copies/ml). In the second month of the therapy the hemoglobin level decreased to 12.9 gr/dL, and then to 9.9 gr/dL in the fourth month, while it was 14.5 gr/dL before anti-retroviral therapy. Although the patient had no hemolysis findings, and his serum folic acid level was normal, folbiol treatment was initiated with the possibility of the presence of folic acid deficiency at cellular level. Anemia resolved with folic acid replacement without discontinuation of zidovudine or a reduction in dosage. It was thought that the presence of alpha-thalassemia co-morbidity has facilitated the development of anti-retroviral-induced anemia in this patient. As a result, it is concluded that thalassemia should be considered in the differential diagnosis of anemia in HIV positive patients, especially for the ones from Mediterranian countries.

  6. Effects of Cinacalcet and Concurrent Low-Dose Vitamin D on FGF23 Levels in ESRD

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    Liu, Shiguang; Krebill, Ron; Menard, Rochelle; Quarles, L. Darryl

    2010-01-01

    Background and objectives: Fibroblast growth factor-23 (FGF23) levels are elevated in ESRD and have been associated with adverse outcomes. The effects of various treatments for secondary hyperparathyroidism on FGF23 levels in ESRD have not been examined in a clinical trial. Design, setting, participants, & measurements: We assessed intact FGF23 levels in 91 subjects over the course of the ACHIEVE trial, which was designed to compare escalating doses of Cinacalcet plus fixed low-dose calcitriol analogs (Cinaclcet-D) with titration of calcitriol analogs alone (Flex-D) to suppress parathyroid hormone. Between-group and within-group changes in log-transformed FGF23 levels were analyzed. Factors associated with change in FGF23 were assessed using a multiple regression model. Results: Intact FGF23 levels were markedly elevated in subjects at baseline. A statistically significant difference in percent change in log FGF23 levels was observed between treatment groups (P < 0.002). The Cinacalcet-D group had a significant decrease in percent change in log FGF23 levels (corrected P = 0.021), whereas FGF23 levels trended toward an increase in the Flex-D group. Change in FGF23 level was significantly associated with changes in levels of phosphate (P < 0.0001) and calcium (P = 0.0002) but not parathyroid hormone. Conclusions: Treatment with Cinacalcet plus low-dose calcitriol analogs results in lower FGF23 levels compared with a treatment regimen using calcitriol analogs alone in ESRD. The mechanisms underlying the differential effects of these treatment regimens on FGF23 levels and the clinical impact of these changes on FGF23 remain to be defined. PMID:19965548

  7. FORMULATION AND EVALUATION OF ZIDOVUDINE CONTROLLED RELEASE GAS POWERED SYSTEM USING HYDROPHILLIC POLYMER

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    N. G. Raghavendra Rao

    2011-03-01

    Full Text Available Zidovudine is the first approved compound for the treatment of AIDS; however the main limitation to therapeutic effectiveness of zidovudine is its dose-dependent toxicity, short biological half-life and poor bioavailability. The present research work an attempt has been made to develop the Zidovudine gas powered drug delivery system for controlled release. The Zidovudine gas powered tablets were prepared by direct compression method by using the different grades of hydrophilic polymer like HPMC. The sodium bicarbonates and citric acid were also used as a gas generating agent. The power blend was subjected for pre-compressional parameters. The prepared gas powered tablets are evaluated to post-compressional analysis of parameter such as hardness, friability, weight variation , thickness, drug content, lag time subsequently buoyancy time and in-vitro dissolution studies and swelling index. All the pre and post-compressional parameter are evaluated the results were within acceptable limits. The results of in-vitro buoyancy time and lag time study, the values of in-vitro buoyancy time ranges from 38 to 960 min where as floating lag time ranges from 3.5 to 60 min. The formulation F4 shows the lag time 3.5 min and buoyancy time 960 min. The results of in-vitro buoyancy time and lag time study revealed that as the concentration of sodium bicarbonate increases there is increase in total buoyancy time and decrease in lag time. It is evident from the in-vitro dissolution data that increase in citric acid concentration increased the release rate but reduced the floating time, probably due to of excess carbon dioxide, disturbing the monolithic tablet. The citric acid level in the formulations greatly influenced the drug release. The formulation, F-4 shows maximum drug release at the end of 12 hrs. Form this study, it is concluded that, the formulation retained for longer periods of time in the stomach and provides controlled release of the drug. Hence it

  8. Simplified spacecraft vulnerability assessments at component level in early design phase at the European Space Agency's Concurrent Design Facility

    Science.gov (United States)

    Kempf, Scott; Schäfer, Frank K.; Cardone, Tiziana; Ferreira, Ivo; Gerené, Sam; Destefanis, Roberto; Grassi, Lilith

    2016-12-01

    During recent years, the state-of-the-art risk assessment of the threat posed to spacecraft by micrometeoroids and space debris has been expanded to the analysis of failure modes of internal spacecraft components. This method can now be used to perform risk analyses for satellites to assess various failure levels - from failure of specific sub-systems to catastrophic break-up. This new assessment methodology is based on triple-wall ballistic limit equations (BLEs), specifically the Schäfer-Ryan-Lambert (SRL) BLE, which is applicable for describing failure threshold levels for satellite components following a hypervelocity impact. The methodology is implemented in the form of the software tool Particle Impact Risk and vulnerability Analysis Tool (PIRAT). During a recent European Space Agency (ESA) funded study, the PIRAT functionality was expanded in order to provide an interface to ESA's Concurrent Design Facility (CDF). The additions include a geometry importer and an OCDT (Open Concurrent Design Tool) interface. The new interface provides both the expanded geometrical flexibility, which is provided by external computer aided design (CAD) modelling, and an ease of import of existing data without the need for extensive preparation of the model. The reduced effort required to perform vulnerability analyses makes it feasible for application during early design phase, at which point modifications to satellite design can be undertaken with relatively little extra effort. The integration of PIRAT in the CDF represents the first time that vulnerability analyses can be performed in-session in ESA's CDF and the first time that comprehensive vulnerability studies can be applied cost-effectively in early design phase in general.

  9. Concurrent and Predictive Validity of the Battelle Development Inventory at the First Grade Level.

    Science.gov (United States)

    Guidubaldi, John; Perry, Joseph D.

    1984-01-01

    A random sample (n=50) of a school district's total grade level was evaluated in kindergarten, then in first grade using a comprehensive battery of assessments. Data were interpreted to support the Battelle Developmental Inventory as a valid multifactored assessment for use with both handicapped and nonhandicapped young children. (Author/BS)

  10. Antecedent and Concurrent Psychosocial Skills That Support High Levels of Achievement within Talent Domains

    Science.gov (United States)

    Olszewski-Kubilius, Paula; Subotnik, Rena F.; Worrell, Frank C.

    2015-01-01

    Motivation and emotional regulation are important for the sustained focused study and practice required for high levels of achievement and creative productivity in adulthood. Using the talent development model proposed by the authors as a framework, the authors discuss several important psychosocial skills based on the psychological research…

  11. Effects of parietal TMS on visual and auditory processing at the primary cortical level -- a concurrent TMS-fMRI study

    DEFF Research Database (Denmark)

    Leitão, Joana; Thielscher, Axel; Werner, Sebastian

    2013-01-01

    Accumulating evidence suggests that multisensory interactions emerge already at the primary cortical level. Specifically, auditory inputs were shown to suppress activations in visual cortices when presented alone but amplify the blood oxygen level-dependent (BOLD) responses to concurrent visual i...

  12. Effect of zidovudine and its interaction with rocuronium on neuromuscular transmission

    Directory of Open Access Journals (Sweden)

    M J Barvaliya

    2013-01-01

    Full Text Available Neuromuscular weakness is often found in patients receiving zidovudine therapy due to mitochondrial damage. Effect of zidovudine was evaluated in indirectly and directly stimulated isolated rat phrenic nerve hemidiaphragm preparations, by cumulative dose response curve with square wave pulses, 0.5 ms duration of 2 Hz at every 10 s. To understand the observed effect of zidovudine, interaction studies were carried out with rocuronium. Dose response curve of rocuronium was compared in the absence and in the presence of 1.2 and 12 mmol/ml zidovudine. In another set of experiment, intact animals were treated with zidovudine 50 and 100 mg/kg for 15 days and phrenic nerve hemidiaphragm was obtained for in vitro experiment. Effect of zidovudine (30 mmol/ml on twitch responses inhibited by dantrolene 50 μmol/ml, magnesium chloride 8 mmol/ml, rocuronium 10 μmol/ml, succinylcholine 25 μmol/ml and lignocaine 600 μmol/ml was studied. Zidovudine (3-30 mmol/ml significantly augmented the twitch responses up to 80 and 40% in indirectly and directly stimulated preparations, respectively (P <0.05. Zidovudine did not show significant interaction with rocuronium in any group as per dose response curve and inhibitory concentration 5%, inhibitory concentration 50% and inhibitory concentration 95% of rocuronium. Zidovudine (30 mmol/ml augmented the twitch responses inhibited by dantrolene, magnesium chloride and rocuronium. It reduced the time for complete block of succinylcholine (P <0.05. Zidovudine affects the neuromuscular transmission. No conclusive interaction between rocuronium and zidovudine was found.

  13. Biowaiver monographs for immediate-release solid oral dosage forms: Zidovudine (azidothymidine).

    Science.gov (United States)

    Soares, Kelen C C; Rediguieri, Camila F; Souza, Jacqueline; Serra, Cristina Helena R; Abrahamsson, Bertil; Groot, D W; Kopp, Sabine; Langguth, Peter; Polli, James E; Shah, Vinod P; Dressman, Jennifer

    2013-08-01

    Literature data on the properties of zidovudine relevant to waiver of in vivo bioequivalence (BE) testing requirements for the approval of immediate-release (IR) solid oral dosage forms containing zidovudine alone or in combination with other active pharmaceutical ingredients (APIs) are reviewed. Solubility, dissolution, and permeability data for zidovudine, along with its dosing schedule, therapeutic index and pharmacokinetic properties, and reports related to BE/bioavailability were all taken into consideration. Data for solubility and permeability suggest that zidovudine belongs to Class I according to the Biopharmaceutics Classification System. Also, zidovudine is not a narrow therapeutic index drug. Although five out of 13 formulations tested in vivo (mostly of unreported composition) failed to show BE, it appears that in vitro studies performed according to biowaiver methods could predict in vivo behavior. Nevertheless, it is highly recommended that if a biowaiver is to be applied, excipient choices be limited to those found in IR drug products approved in International Conference on Harmonisation (ICH) or associated countries in the same dosage form (Table 2 of this monograph), in their usual amounts. These conclusions apply to products containing zidovudine as the only API and also to fixed combination products containing zidovudine with respect to the zidovudine component of the formulation.

  14. Building Safe Concurrency Abstractions

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    2014-01-01

    Concurrent object-oriented programming in Beta is based on semaphores and coroutines and the ability to define high-level concurrency abstractions like monitors, and rendezvous-based communication, and their associated schedulers. The coroutine mechanism of SIMULA has been generalized...... into the notions of concurrent and alternating objects. Alternating objects may be used to start a cooperative thread for each possible blocking communication and is thus an alternative to asynchronous messages and guarded commands. Beta like SIMULA, the first OO language, was designed as a language for modeling...... as well as programming, and we describe how this has had an impact on the design of the language. Although Beta supports the definition of high-level concurrency abstractions, the use of these rely on the discipline of the programmer as is the case for Java and other mainstream OO languages. We introduce...

  15. Concurrency engineering

    NARCIS (Netherlands)

    Jesshope, C.; Shafarenko, A.

    2008-01-01

    This is a discussion paper on a very important topic that is about to become mainstream. It deals with the issues of software engineering in concurrent systems. It introduces this topic and illustrates the arguments for a change of perspective. It underlines these arguments with two examples, an

  16. Early features of zidovudine-associated myopathy: histopathological findings and clinical correlations.

    Science.gov (United States)

    Cupler, E J; Danon, M J; Jay, C; Hench, K; Ropka, M; Dalakas, M C

    1995-01-01

    Zidovudine-induced myopathy is characterized by reversible muscle weakness, wasting, myalgia, fatigue, and elevated creatine kinase (CK). Some zidovudine-treated patients with normal muscle strength experience excessive fatigue, myalgia, or transient mild CK elevations that improve when zidovudine is stopped. To determine the cause of these symptoms, we studied 13 physically fit, HIV-infected men who developed fatigue, myalgia, and reduced endurance, while taking zidovudine for a mean period of 20 months (2-39 months), with neurological evaluation and muscle biopsy processed for enzyme histochemistry and electron microscopy (EM). All subjects had normal muscle strength. In 6 of the 13 patients, muscle biopsies were normal by enzyme histochemistry. EM, however, demonstrated proliferation of normal or abnormal mitochondria, and increased amounts of lipid, glycogen, and lipofuscin. Electromyographic (EMG) studies (5/5) and serum CK (6/6) were normal. The other 7 individuals had signs of moderate to severe mitochondrial abnormalities shown by both light microscopy and EM, characterized by severe destruction, vacuolization, and rare paracrystalline inclusions. Most had elevated CK (4 out of 7) and normal EMG (5 out of 7). The severity of morphological abnormalities did not correlate with duration of HIV infection, zidovudine therapy, or zidovudine dosage. We conclude that in zidovudine-treated patients, symptoms of fatigue, myalgia, reduced endurance, and exercise intolerance represent early signs of zidovudine-induced mitochondriotoxicity, which causes an energy shortage within the muscle fibers even when muscle strength is still normal. Zidovudine, a DNA chain terminator, results in overt myopathy when a critical threshold of molecular, histological, and biochemical dysfunction of mitochondria is crossed, which seems to vary between individuals.

  17. Refracture of osteoporotic vertebral body concurrent with cement fragmentation at the previously treated vertebral level after balloon kyphoplasty: a case report.

    Science.gov (United States)

    Li, Xigong; Lou, Xianfeng; Lin, Xiangjin; Du, Junhua

    2014-05-01

    Kyphoplasty has been shown to provide symptomatic relief of vertebral compression fractures refractory to medical therapy. However, few reports have focused on refracture of cemented vertebrae after kyphoplasty. The presence of cemented vertebrae refracture concurrent with cement fragmentation is an extremely rare condition. We reported an 86-year-old man with a T12 osteoporotic compression fracture undergoing the kyphoplasty treatment. The patient postoperatively continued to have back pain at the same level. The solid lumped polymethylmethacrylate (PMMA) mass and inadequate use and insufficient filling of PMMA cement were observed in postoperative radiographs and magnetic resonance image (MRI) examination. He refused to receive the surgical intervention, but had not strict compliance with oral anti-osteoporotic medications. Ten months postoperatively, refracture of osteoporotic vertebral body concurrent with cement fragmentation occurred at the previously kyphoplasty-treated vertebral level. Bone mineral analysis showed severe osteoporosis with a T-score of -4.0. The patient finally obtained therapeutic benefit of pain relief and bony union of T12 vertebral body by consistently adhering to anti-osteoporotic medication treatment. This case illustrated that patients who underwent kyphoplasty to treat osteoporotic vertebral compression fractures with intravertebral fracture should be strictly followed up and supervised in their anti-osteoporotic medication treatment. The interdigitation injection pattern of PMMA and sufficient PMMA filling with trabeculae in the kyphoplasty procedure also might prevent refracture of the cemented vertebrae concurrent with PMMA fragmentation.

  18. Mechanisms of zidovudine-induced mitochondrial toxicity and myopathy.

    Science.gov (United States)

    Scruggs, Erin R; Dirks Naylor, Amie J

    2008-01-01

    Zidovudine (3-azido-3'-deoxythymidine), also referred to as azidothymidine (AZT), has become an integral component in highly active antiretroviral therapy, and has also been used in the treatment of cancer. The clinical effectiveness of AZT is constrained due to its association with increased adverse effects, such as myopathy. There are numerous potential mechanisms that may contribute to AZT-induced myopathy. The first hypothesized mechanism to explain AZT-induced toxicity was mtDNA depletion due to inhibition of DNA polymerase gamma. Although mtDNA depletion is present in patients with myopathy, current data suggests that alternative mechanisms may play a more direct role in the myotoxicity. These mechanisms include AZT-induced oxidative stress, direct inhibition of mitochondrial bioenergetic machinery, and mitochondrial depletion of L-carnitine. Furthermore, we hypothesize that apoptosis may play a role in AZT-induced myopathy.

  19. Synthesis and antiretroviral evaluation of derivatives of zidovudine

    Energy Technology Data Exchange (ETDEWEB)

    Raviolo, Monica A.; Brin, Margarita C. [Universidad Nacional de Cordoba, Cordoba (Argentina). Facultad de Ciencias Quimicas. Dept. de Farmacia; Trinchero-Hernandez, Juan S.; Turk, Gabriela [Universidad de Buenos Aires, Buenos Aires (Argentina). Facultad de Medicina. Centro Nacional de Referencia para el SIDA

    2009-07-01

    A series of zidovudine (AZT, 1) derivatives have been synthesized and their anti-HIV activity and cytotoxicity have been determined. The 5'-OH function of AZT was derivatized using N, N'-carbonyldiimidazole and different amine compounds leading to their 5'-O-carbamates. In addition, two known AZT derivatives 5'-O-tosylate and a tricyclic one (AZT-Cycl) were also obtained by a simpler procedure than those previously reported. Although these AZT derivatives were less toxic than AZT, their reduced cytotoxicity was concomitant with an inability to inhibit HIV-1 replication, except in the case of AZT-Cycl, which showed an IC{sub 50} = 1 {mu}mol L{sup -1} without cytotoxicity with values of CCID{sub 50} ({mu}mol L{sup -1}) > 1000. (author)

  20. Building Safe Concurrency Abstractions

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    2014-01-01

    into the notions of concurrent and alternating objects. Alternating objects may be used to start a cooperative thread for each possible blocking communication and is thus an alternative to asynchronous messages and guarded commands. Beta like SIMULA, the first OO language, was designed as a language for modeling...... as well as programming, and we describe how this has had an impact on the design of the language. Although Beta supports the definition of high-level concurrency abstractions, the use of these rely on the discipline of the programmer as is the case for Java and other mainstream OO languages. We introduce...

  1. Zidovudine-induced mitochondrial myopathy is associated with muscle carnitine deficiency and lipid storage.

    Science.gov (United States)

    Dalakas, M C; Leon-Monzon, M E; Bernardini, I; Gahl, W A; Jay, C A

    1994-04-01

    The use of zidovudine (AZT) for the treatment of acquired immunodeficiency syndrome (AIDS) induces a DNA-depleting mitochondrial myopathy, which is histologically characterized by the presence of muscle fibers with "ragged-red"-like features, red-rimmed or empty cracks, granular degeneration, and rods (AZT fibers). Because dysfunctioning muscle mitochondria may lead to defects of beta-oxidation of fatty acids, we examined the degree of neutral fat accumulation and muscle carnitine levels in the muscle biopsy specimens from 21 patients with AZT-induced myopathic symptoms of varying severity. Six patients with no AZT fibers had normal endomyofibrillar lipid deposits and muscle carnitine levels; 7 patients with fewer than 5 AZT fibers per field had a mild (+) to moderate (++) increase in lipid droplets, and reduced muscle carnitine levels (3 patients); and 8 patients with more than 5 AZT fibers had severe muscle changes, a ++ to marked ( ) increase in lipid droplets, and reduced muscle carnitine levels (6 patients). Serial sections showed lipid globules often within "cracks" or vacuoles of the abnormal muscle fibers. We conclude that the muscle mitochondrial impairment caused by AZT results in (1) accumulation of lipid within the muscle fibers owing to poor utilization of long-chain fatty acids, (2) reduction of muscle carnitine levels probably due to decreased carnitine uptake by the muscle, and (3) depletion of energy stores within the muscle fibers. The findings may have potential therapeutic implications in the treatment of AZT-induced myopathic symptoms using oral carnitine supplementation.

  2. Toward global standards for comparator pharmaceutical products: case studies of amoxicillin, metronidazole, and zidovudine in the Americas.

    Science.gov (United States)

    Löbenberg, Raimar; Chacra, Nadia B; Stippler, Erika S; Shah, Vinod P; DeStefano, Anthony J; Hauck, Walter W; Williams, Roger L

    2012-09-01

    This study compared in vitro dissolution characteristics and other quality measures of different amoxicillin, metronidazole, and zidovudine products purchased in the Americas to a comparator pharmaceutical product (CPP). These three drugs are classified as Biopharmaceutics Classification System Class I drugs with the possibility that dissolution findings might be used to document bioequivalence. All investigated zidovudine products were found to be in vitro equivalent to the CPP. Only 3 of 12 tested amoxicillin products were found to be in vitro equivalent to the CPP. None of the tested metronidazole products were in vitro equivalent to the CPP. These findings suggest but do not confirm bioinequivalence where in vitro comparisons failed, given that an in vivo blood level study might have confirmed bioequivalence. At times, identifying a CPP in one of the selected markets proved difficult. The study demonstrates that products sold across national markets may not be bioequivalent. When coupled with the challenge of identifying a CPP in different countries, the results of this study suggest the value of an international CPP as well as increased use of BCS approaches as means of either documenting bioequivalence or signaling the need for further in vivo studies. Because of increased movement of medicines across national borders, practitioners and patients would benefit from these approaches.

  3. Exposure of Allium cepa root cells to zidovudine or nevirapine induces cytogenotoxic changes.

    Science.gov (United States)

    Onwuamah, Chika K; Ekama, Sabdat O; Audu, Rosemary A; Ezechi, Oliver C; Poirier, Miriam C; Odeigah, Peter G C

    2014-01-01

    Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource-poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p=0.004), but not nevirapine dose (p=0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced.

  4. Exposure of Allium cepa root cells to zidovudine or nevirapine induces cytogenotoxic changes.

    Directory of Open Access Journals (Sweden)

    Chika K Onwuamah

    Full Text Available Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource-poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p=0.004, but not nevirapine dose (p=0.68. Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced.

  5. Effects of parietal TMS on visual and auditory processing at the primary cortical level -- a concurrent TMS-fMRI study.

    Science.gov (United States)

    Leitão, Joana; Thielscher, Axel; Werner, Sebastian; Pohmann, Rolf; Noppeney, Uta

    2013-04-01

    Accumulating evidence suggests that multisensory interactions emerge already at the primary cortical level. Specifically, auditory inputs were shown to suppress activations in visual cortices when presented alone but amplify the blood oxygen level-dependent (BOLD) responses to concurrent visual inputs (and vice versa). This concurrent transcranial magnetic stimulation-functional magnetic resonance imaging (TMS-fMRI) study applied repetitive TMS trains at no, low, and high intensity over right intraparietal sulcus (IPS) and vertex to investigate top-down influences on visual and auditory cortices under 3 sensory contexts: visual, auditory, and no stimulation. IPS-TMS increased activations in auditory cortices irrespective of sensory context as a result of direct and nonspecific auditory TMS side effects. In contrast, IPS-TMS modulated activations in the visual cortex in a state-dependent fashion: it deactivated the visual cortex under no and auditory stimulation but amplified the BOLD response to visual stimulation. However, only the response amplification to visual stimulation was selective for IPS-TMS, while the deactivations observed for IPS- and Vertex-TMS resulted from crossmodal deactivations induced by auditory activity to TMS sounds. TMS to IPS may increase the responses in visual (or auditory) cortices to visual (or auditory) stimulation via a gain control mechanism or crossmodal interactions. Collectively, our results demonstrate that understanding TMS effects on (uni)sensory processing requires a multisensory perspective.

  6. Partnership concurrency and coital frequency.

    Science.gov (United States)

    Gaydosh, Lauren; Reniers, Georges; Helleringer, Stéphane

    2013-09-01

    National HIV prevalence estimates across sub-Saharan Africa range from less than 1 percent to over 25 percent. Recent research proposes several explanations for the observed variation, including prevalence of male circumcision, levels of condom use, presence of other sexually transmitted infections, and practice of multiple concurrent partnerships. However, the importance of partnership concurrency for HIV transmission may depend on how it affects coital frequency with each partner. The coital dilution hypothesis suggests that coital frequency within a partnership declines with the addition of concurrent partners. Using sexual behavior data from rural Malawi and urban Kenya, we investigate the relationship between partnership concurrency and coital frequency, and find partial support for the coital dilution hypothesis. We conclude the paper with a discussion of our findings in light of the current literature on concurrency.

  7. Sustained high proportion of zidovudine-resistant HIV variants despite prolonged substitution of zidovudine by other nucleoside reverse transcriptase inhibitors.

    Science.gov (United States)

    Bélec, Laurent; Legoff, Jérôme; Si-Mohamed, Ali; Andréoletti, Laurent; Mbopi-Kéou, François-Xavier; Kolberg, Janice; Matta, Mathieu; Detmer, Jill; Piketty, Christophe; Kazatchkine, Michel D

    2002-09-01

    The consequences of zidovudine (ZDV) replacement by other nucleoside reverse transcriptase inhibitors on the expression of resistance mutations at codons 215 and 41 of the reverse transcriptase (RT) gene was investigated prospectively in 66 patients harboring mutant genotypes who were changed to an effective two- or three-drug combination antiretroviral regimen. Quantitation of mutant (MUT) viral populations at codon 215 by means of RT-PCR with differential hybridization of amplicons specific for MUT and wild (WT) variants revealed no difference in the proportion of 215 MUT variants prior to (93.5 +/- 2.4%) and 12 to 20 months after (96.9 +/- 1.9%) ZDV replacement, independently of a therapeutic change for stavudine. The fitness of the variants harboring the ZDV-resistant MUT 215 genotype following drug withdrawal was calculated to be 96 to 99% of that of the variants harboring the WT 215 genotype. The apparent stability of ZDV-resistant variants in the study population may have two main complementary explanations: persistent selective pressure secondary to partial cross-resistance due to the new regimens given after the therapeutic alteration and suppression of viral replication after the therapeutic alteration that could have hampered the replacement of less fit variants by fitter variants. These findings indicate that, at least within 15 months following discontinuation of ZDV, an effective antiretroviral therapy is insufficient to allow for ZDV-resistant strains to disappear, and thus to allow for the safe re-introduction of the drug.

  8. High Incidence of Zidovudine Induced Anaemia in HIV Infected Patients in Southern Odisha.

    Science.gov (United States)

    Dash, Kaibalya Ranjan; Meher, Lalit Kumar; Hui, P K; Behera, S K; Nayak, S N

    2015-06-01

    Zidovudine (AZT), a nucleoside reverse transcriptase inhibitor was the first breakthrough in AIDS therapy in 1990.This study was conducted with an aim to determine prevalence of AZT induced anaemia in HIV infected patients initiated on AZT containing anti retroviral therapy(ART) regimen and also to find out any risk factor for causing AZT induced anaemia. Study was carried out in ART centre, M.K.C.G, MCH, Berhampur between Jan 2009 and Dec 2011. HIV infected patients registered at ART centre were treated according to National AIDS Control Organisation (NACO) guidelines. Patients (n = 1221) with Hb >8 gm/dl were prescribed AZT based ART regimen. Patients having anaemia (<8 gm/dl) were excluded from the study. Correlation of baseline characteristics (age, sex, weight, Hb level, CD4 count, World Health Organization (WHO) clinical stage) with risk of developing anaemia was also calculated. 178 (14.6 %) patients on AZT regimen developed anaemia. Patients with low CD4 count were more prone to develop severe anaemia. Age, sex, weight, WHO clinical stage had no relation with development of anaemia. Incidence of AZT induced anaemia was very high and patients having low CD4 count were more susceptible to develop anaemia.

  9. Immobilization of Zidovudine Derivatives on the SBA-15 Mesoporous Silica and Evaluation of Their Cytotoxic Activity.

    Science.gov (United States)

    Lewandowski, Dawid; Lewandowska, Marta; Ruszkowski, Piotr; Pińska, Anita; Schroeder, Grzegorz

    2015-01-01

    Novel zidovudine derivatives, able to be covalently conjugated to silica surface, have been obtained and grafted to SBA-15 mesoporous silica. Cytotoxic activity of the hybrid organic-inorganic (zidovudine derivatives-silica) systems against HeLa and KB cell lines has been analyzed. Addition of folic acid had a positive influence on the cytotoxicity. Up to 69% of HeLa and 65% of KB tumor cells growth inhibition has been achieved at low silica concentration used (10 μg/mL).

  10. New methods of concurrent checking

    CERN Document Server

    Goessel, Michael; Sogomonyan, Egor; Marienfeld, Daniel

    2008-01-01

    Written by a team of two leading experts and two very successful young former PhD students, New Methods of Concurrent Checking describes new methods of concurrent checking, such as partial duplication, use of output dependencies, complementary circuits, self-dual parity, self-dual duplication and others. A special chapter demonstrates how the new general methods of concurrent checking can be more specifically applied to regular structures to obtain optimum results. This is exemplified for all types of adders up to 64 bits with a level of detail never before presented in the literature. The cle

  11. Leader-Member Exchange across two hierarchical levels of leadership: concurrent influences on work characteristics and employee psychological health.

    Science.gov (United States)

    Karanika-Murray, Maria; Bartholomew, Kimberley J; Williams, Glenn A; Cox, Tom

    2015-01-02

    Leader-Member Exchange (LMX) theory suggests that the quality of the leader-employee relationship is linked to employee psychological health. Leaders who reside at different hierarchical levels have unique roles and spheres of influence and potentially affect employees' work experiences in different ways. Nevertheless, research on the impact of leadership on employee psychological health has largely viewed leaders as a homogeneous group. Expanding on LMX theory, we argue that (1) LMX sourced at the levels of the line manager (LM) and senior management (SM) team will be differentially linked to employee psychological health (assessed as worn-out) and that (2) these relationships will be mediated by perceived work characteristics (reward and recognition, workload management, quality of relationships with colleagues and physical environment). Structural equation modelling on data from 337 manual workers partially supported the hypotheses. Perceptions of the physical environment mediated the relationship between LMX at the LM level and employee psychological health, whereas perceptions of workload management mediated the relationship between LMX at the SM level and psychological health. These findings corroborate arguments that leaders are not a uniform group and as such the effects of LMX on employees will depend on leadership hierarchy. Implications for expanding leadership theory are discussed.

  12. Leader-Member Exchange across two hierarchical levels of leadership: concurrent influences on work characteristics and employee psychological health

    Science.gov (United States)

    Karanika-Murray, Maria; Bartholomew, Kimberley J.; Williams, Glenn A.; Cox, Tom

    2015-01-01

    Leader-Member Exchange (LMX) theory suggests that the quality of the leader–employee relationship is linked to employee psychological health. Leaders who reside at different hierarchical levels have unique roles and spheres of influence and potentially affect employees' work experiences in different ways. Nevertheless, research on the impact of leadership on employee psychological health has largely viewed leaders as a homogeneous group. Expanding on LMX theory, we argue that (1) LMX sourced at the levels of the line manager (LM) and senior management (SM) team will be differentially linked to employee psychological health (assessed as worn-out) and that (2) these relationships will be mediated by perceived work characteristics (reward and recognition, workload management, quality of relationships with colleagues and physical environment). Structural equation modelling on data from 337 manual workers partially supported the hypotheses. Perceptions of the physical environment mediated the relationship between LMX at the LM level and employee psychological health, whereas perceptions of workload management mediated the relationship between LMX at the SM level and psychological health. These findings corroborate arguments that leaders are not a uniform group and as such the effects of LMX on employees will depend on leadership hierarchy. Implications for expanding leadership theory are discussed. PMID:25999635

  13. Comparison of long-term prognosis of patients with AIDS treated and not treated with zidovudine. AIDS in Europe Study Group

    DEFF Research Database (Denmark)

    Lundgren, Jens Dilling; Phillips, A N; Pedersen, C;

    1994-01-01

    OBJECTIVE--To determine the association between elapsed time since starting zidovudine and survival in patients with acquired immunodeficiency syndrome (AIDS). DESIGN--Inception cohort and observational study of patients treated and not treated with zidovudine. SETTING--Fifty-one centers in 17...... European countries. PATIENTS--A total of 4484 patients diagnosed as having AIDS from 1979 to 1989 who survived their initial AIDS-defining event and who had not started zidovudine before AIDS diagnosis. MAIN OUTCOME MEASURES--Use of zidovudine and mortality. RESULTS--Among patients who did not receive...... zidovudine, the death rate was approximately constant for the first 5 years after AIDS diagnosis. For patients treated with zidovudine, the death rate within the first year since starting zidovudine was markedly lower than for untreated patients who had developed AIDS at the same time (relative rate, 0...

  14. ERCC1 mRNA levels can predict the response to cisplatin-based concurrent chemoradiotherapy of locally advanced cervical squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Bai Zhou-lan

    2012-12-01

    Full Text Available Abstract Background The purpose of this study was to investigate whether the excision repair cross-complementation group 1 (ERCC1 mRNA expression could predict treatment response of patients with locally advanced cervical squamous cell carcinoma (LACSCC who underwent cisplatin-based concurrent chemoradiotherapy (CCCRT. Methods A total of sixty LACSCC patients, treated with radical CCCRT from a single institution were evaluated. ERCC1 mRNA expression was determined by quantitative real-time RT-PCR in pre-treatment tumor tissues. The association of ERCC1 status with clinicopathological characteristics (age, histological grade, tumor size, parametrial invasion, lymph node metastasis and FIGO stage and treatment response were analyzed. Results No significant association between ERCC1 mRNA expression and clinicopathological characteristics were observed. Patients with low ERCC1 mRNA level had a significantly higher rate of complete response (86.21% than patients with high level of ERCC1 expression (19.36%; p P  Conclusions This is the first analysis of the association between ERCC1 mRNA levels and treatment response in patients with LACSCC. Low ERCC1 mRNA level appears to be a highly specific predictor of response to CCCRT in LACSCC.

  15. Basic Concurrency Theory

    DEFF Research Database (Denmark)

    Løvengreen, Hans Henrik

    2002-01-01

    In this set of notes, we present some of the basic theory underlying the discipline of programming with concurrent processes/threads. The notes are intended to supplement a standard textbook on concurrent programming.......In this set of notes, we present some of the basic theory underlying the discipline of programming with concurrent processes/threads. The notes are intended to supplement a standard textbook on concurrent programming....

  16. Concurrent weighted logic

    DEFF Research Database (Denmark)

    Xue, Bingtian; Larsen, Kim Guldstrand; Mardare, Radu Iulian

    2015-01-01

    We introduce Concurrent Weighted Logic (CWL), a multimodal logic for concurrent labeled weighted transition systems (LWSs). The synchronization of LWSs is described using dedicated functions that, in various concurrency paradigms, allow us to encode the compositionality of LWSs. To reflect these......-completeness results for this logic. To complete these proofs we involve advanced topological techniques from Model Theory....

  17. Oral Mucositis Prevention By Low-Level Laser Therapy in Head-and-Neck Cancer Patients Undergoing Concurrent Chemoradiotherapy: A Phase III Randomized Study

    Energy Technology Data Exchange (ETDEWEB)

    Gouvea de Lima, Aline [Departamento de Radiologia, Disciplina de Oncologia, Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Villar, Rosangela Correa [Instituto de Radiologia, Servico de Radioterapia, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Castro, Gilberto de, E-mail: gilberto.castro@usp.br [Department of Clinical Oncology, Instituto do Cancer do Estado de Sao Paulo, Sao Paulo, SP (Brazil); Antequera, Reynaldo [Divisao de Odontologia, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Gil, Erlon; Rosalmeida, Mauro Cabral [Instituto de Radiologia, Servico de Radioterapia, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Federico, Miriam Hatsue Honda; Snitcovsky, Igor Moises Longo [Departamento de Radiologia, Disciplina de Oncologia, Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, SP (Brazil)

    2012-01-01

    Purpose: Oral mucositis is a major complication of concurrent chemoradiotherapy (CRT) in head-and-neck cancer patients. Low-level laser (LLL) therapy is a promising preventive therapy. We aimed to evaluate the efficacy of LLL therapy to decrease severe oral mucositis and its effect on RT interruptions. Methods and Materials: In the present randomized, double-blind, Phase III study, patients received either gallium-aluminum-arsenide LLL therapy 2.5 J/cm{sup 2} or placebo laser, before each radiation fraction. Eligible patients had to have been diagnosed with squamous cell carcinoma or undifferentiated carcinoma of the oral cavity, pharynx, larynx, or metastases to the neck with an unknown primary site. They were treated with adjuvant or definitive CRT, consisting of conventional RT 60-70 Gy (range, 1.8-2.0 Gy/d, 5 times/wk) and concurrent cisplatin. The primary endpoints were the oral mucositis severity in Weeks 2, 4, and 6 and the number of RT interruptions because of mucositis. The secondary endpoints included patient-reported pain scores. To detect a decrease in the incidence of Grade 3 or 4 oral mucositis from 80% to 50%, we planned to enroll 74 patients. Results: A total of 75 patients were included, and 37 patients received preventive LLL therapy. The mean delivered radiation dose was greater in the patients treated with LLL (69.4 vs. 67.9 Gy, p = .03). During CRT, the number of patients diagnosed with Grade 3 or 4 oral mucositis treated with LLL vs. placebo was 4 vs. 5 (Week 2, p = 1.0), 4 vs. 12 (Week 4, p = .08), and 8 vs. 9 (Week 6, p = 1.0), respectively. More of the patients treated with placebo had RT interruptions because of mucositis (6 vs. 0, p = .02). No difference was detected between the treatment arms in the incidence of severe pain. Conclusions: LLL therapy was not effective in reducing severe oral mucositis, although a marginal benefit could not be excluded. It reduced RT interruptions in these head-and-neck cancer patients, which might

  18. Blood oxygenation level-dependent MR imaging as a predictor of therapeutic response to concurrent chemoradiotherapy in cervical cancer: a preliminary experience

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Kyo; Park, Sung Yoon; Park, Byung Kwan [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Park, Won; Huh, Seung Jae [Sungkyunkwan University School of Medicine, Department of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2014-07-15

    To investigate the value of blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) as a predictor of therapeutic response in cervical cancer patients undergoing concurrent chemoradiotherapy (CCRT). Thirty consecutive patients with biopsy-proven cervical cancer were examined by BOLD MRI before (preTx) and after CCRT (postTx). The R2* value (s{sup -1}) was calculated in the tumour and normal myometrium for preTx and postTx studies. Final tumour responses, as determined by changes of tumour size or volume on MRI, were correlated with tumour R2* values at preTx. The mean R2* values of tumours at preTx (21.1) were significantly lower than those at postTx (39.4 s{sup -1}) (p < 0.001), while those of normal myometrium were similar between preTx and postTx (p = 0.363). At preTx, tumour R2* values showed significantly negative correlation with final tumour size response (p = 0.022, Spearman's coefficient = -0.415). However, tumour R2* values at preTx were not associated with final tumour volume response (p = 0.069). BOLD MRI at 3 T, as an imaging biomarker, may have the potential to evaluate therapeutic response in cervical cancers. The association between BOLD MRI findings and CCRT responses warrants further validation. (orig.)

  19. A report on high-level nuclear waste transportation: Prepared pursuant to assembly concurrent resolution No. 8 of the 1987 Nevada Legislature

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-12-01

    This report has been prepared by the staff of the State of Nevada Agency for Nuclear Projects/Nuclear Waste Project Office (NWPO) in response to Assembly Concurrent Resolution No. 8 (ACR 8), passed by the Nevada State Legislature in 1987. ACR 8 directed the NWPO, in cooperation with affected local governments and the Legislative committee on High-Level Radioactive Waste, to prepare this report which scrutinizes the US Department of Energy`s (DOE) plans for transportation of high-level radioactive waste to the proposed yucca Mountain repository, which reviews the regulatory structure under which shipments to a repository would be made and which presents NWPO`s plans for addressing high-level radioactive waste transportation issues. The report is divided into three major sections. Section 1.0 provides a review of DOE`s statutory requirements, its repository transportation program and plans, the major policy, programmatic, technical and institutional issues and specific areas of concern for the State of Nevada. Section 2.0 contains a description of the current federal, state and tribal transportation regulatory environment within which nuclear waste is shipped and a discussion of regulatory issues which must be resolved in order for the State to minimize risks and adverse impacts to its citizens. Section 3.0 contains the NWPO plan for the study and management of repository-related transportation. The plan addresses four areas, including policy and program management, regulatory studies, technical reviews and studies and institutional relationships. A fourth section provides recommendations for consideration by State and local officials which would assist the State in meeting the objectives of the plan.

  20. Krill protein hydrolysate reduces plasma triacylglycerol level with concurrent increase in plasma bile acid level and hepatic fatty acid catabolism in high-fat fed mice

    Directory of Open Access Journals (Sweden)

    Marie S. Ramsvik

    2013-11-01

    Full Text Available Background: Krill powder, consisting of both lipids and proteins, has been reported to modulate hepatic lipid catabolism in animals. Fish protein hydrolysate diets have also been reported to affect lipid metabolism and to elevate bile acid (BA level in plasma. BA interacts with a number of nuclear receptors and thus affects a variety of signaling pathways, including very low density lipoprotein (VLDL secretion. The aim of the present study was to investigate whether a krill protein hydrolysate (KPH could affect lipid and BA metabolism in mice. Method: C57BL/6 mice were fed a high-fat (21%, w/w diet containing 20% crude protein (w/w as casein (control group or KPH for 6 weeks. Lipids and fatty acid composition were measured from plasma, enzyme activity and gene expression were analyzed from liver samples, and BA was measured from plasma. Results: The effect of dietary treatment with KPH resulted in reduced levels of plasma triacylglycerols (TAG and non-esterified fatty acids (NEFAs. The KPH treated mice had also a marked increased plasma BA concentration. The increased plasma BA level was associated with induction of genes related to membrane canalicular exporter proteins (Abcc2, Abcb4 and to BA exporters to blood (Abcc3 and Abcc4. Of note, we observed a 2-fold increased nuclear farnesoid X receptor (Fxr mRNA levels in the liver of mice fed KPH. We also observed increased activity of the nuclear peroxiosme proliferator-activated receptor alpha (PPARα target gene carnitine plamitoyltransferase 2 (CPT-2. Conclusion: The KPH diet showed to influence lipid and BA metabolism in high-fat fed mice. Moreover, increased mitochondrial fatty acid oxidation and elevation of BA concentration may regulate the plasma level of TAGs and NEFAs.

  1. Constraints meet concurrency

    CERN Document Server

    Mauro, Jacopo

    2014-01-01

    This book describes the benefits that emerge when the fields of constraint programming and concurrency meet. On the one hand, constraints can be used in concurrency theory to increase the conciseness and the expressive power of concurrent languages from a pragmatic point of view. On the other hand, problems modeled by using constraints can be solved faster and more efficiently using a concurrent system. Both directions are explored providing two separate lines of development. Firstly the expressive power of a concurrent language is studied, namely Constraint Handling Rules, that supports constraints as a primitive construct. The features of this language which make it Turing powerful are shown. Then a framework is proposed to solve constraint problems that is intended to be deployed on a concurrent system. For the development of this framework the concurrent language Jolie following the Service Oriented paradigm is used. Based on this experience, an extension to Service Oriented Languages is also proposed in ...

  2. Spectra resolution for simultaneous spectrophotometric determination of lamivudine and zidovudine components in pharmaceutical formulation of human immunodeficiency virus drug based on using continuous wavelet transform and derivative transform techniques.

    Science.gov (United States)

    Sohrabi, Mahmoud Reza; Tayefeh Zarkesh, Mahshid

    2014-05-01

    In the present paper, two spectrophotometric methods based on signal processing are proposed for the simultaneous determination of two components of an anti-HIV drug called lamivudine (LMV) and zidovudine (ZDV). The proposed methods are applied to synthetic binary mixtures and commercial pharmaceutical tablets without the need for any chemical separation procedures. The developed methods are based on the application of Continuous Wavelet Transform (CWT) and Derivative Spectrophotometry (DS) combined with the zero cross point technique. The Daubechies (db5) wavelet family (242 nm) and Dmey wavelet family (236 nm) were found to give the best results under optimum conditions for simultaneous analysis of lamivudine and zidovudine, respectively. In addition, the first derivative absorption spectra were selected for the determination of lamivudine and zidovudine at 266 nm and 248 nm, respectively. Assaying various synthetic mixtures of the components validated the presented methods. Mean recovery values were found to be between 100.31% and 100.2% for CWT and 99.42% and 97.37% for DS, respectively for determination of LMV and ZDV. The results obtained from analyzing the real samples by the proposed methods were compared to the HPLC reference method. One-way ANOVA test at 95% confidence level was applied to the results. The statistical data from comparing the proposed methods with the reference method showed no significant differences.

  3. Serum thymidine kinase--a marker of bone marrow toxicity during treatment with zidovudine

    DEFF Research Database (Denmark)

    Pedersen, C; Ingeberg, S; Teglbjærg, Lars Stubbe

    1989-01-01

    of their usual treatment. There was a significant association between S-TK, haemoglobin and neutrophil counts measured after the first 4 weeks of therapy and the risk of developing bone marrow toxicity during the following 6 months. Combined, measurements of S-TK and neutrophil counts seem to be well suited...... for the identification of patients who have a high probability for developing bone marrow toxicity during zidovudine treatment....

  4. Towards Composable Concurrency Abstractions

    Directory of Open Access Journals (Sweden)

    Janwillem Swalens

    2014-06-01

    Full Text Available In the past decades, many different programming models for managing concurrency in applications have been proposed, such as the actor model, Communicating Sequential Processes, and Software Transactional Memory. The ubiquity of multi-core processors has made harnessing concurrency even more important. We observe that modern languages, such as Scala, Clojure, or F#, provide not one, but multiple concurrency models that help developers manage concurrency. Large end-user applications are rarely built using just a single concurrency model. Programmers need to manage a responsive UI, deal with file or network I/O, asynchronous workflows, and shared resources. Different concurrency models facilitate different requirements. This raises the issue of how these concurrency models interact, and whether they are composable. After all, combining different concurrency models may lead to subtle bugs or inconsistencies. In this paper, we perform an in-depth study of the concurrency abstractions provided by the Clojure language. We study all pairwise combinations of the abstractions, noting which ones compose without issues, and which do not. We make an attempt to abstract from the specifics of Clojure, identifying the general properties of concurrency models that facilitate or hinder composition.

  5. Zidovudine, abacavir and lamivudine increase the radiosensitivity of human esophageal squamous cancer cell lines.

    Science.gov (United States)

    Chen, Xuan; Wang, Cong; Guan, Shanghui; Liu, Yuan; Han, Lihui; Cheng, Yufeng

    2016-07-01

    Telomerase is a type of reverse transcriptase that is overexpressed in almost all human tumor cells, but not in normal tissues, which provides an opportunity for radiosensitization targeting telomerase. Zidovudine, abacavir and lamivudine are reverse transcriptase inhibitors that have been applied in clinical practice for several years. We sought to explore the radiosensitization effect of these three drugs on human esophageal cancer cell lines. Eca109 and Eca9706 cells were treated with zidovudine, abacavir and lamivudine for 48 h before irradiation was administered. Samples were collected 1 h after irradiation. Clonal efficiency assay was used to evaluate the effect of the combination of these drugs with radiation doses of 2, 4, 6 and 8 Gy. DNA damage was measured by comet assay. Telomerase activity (TA) and relative telomere length (TL) were detected and evaluated by real-time PCR. Apoptosis rates were assessed by flow cytometric analysis. The results showed that all the drugs tested sensitized the esophageal squamous cell carcinoma (ESCC) cell lines to radiation through an increase in radiation-induced DNA damage and cell apoptosis, deregulation of TA and decreasing the shortened TL caused by radiation. Each of the drugs investigated (zidovudine, abacavir and lamivudine) could be used for sensitizing human esophageal cancer cell lines to radiation. Consequently, the present study supports the potential of these three drugs as therapeutic agents for the radiosensitization of esophageal squamous cell cancer.

  6. Effect of maraviroc on the pharmacokinetics of midazolam, lamivudine/ zidovudine, and ethinyloestradiol/ levonorgestrel in healthy volunteers

    Science.gov (United States)

    Abel, Samantha; Russell, Deborah; Whitlock, Lyndsey A; Ridgway, Caroline E; Muirhead, Gary J

    2008-01-01

    Aims To assess the effect of maraviroc on the pharmacokinetics of midazolam, a sensitive probe CYP3A4 substrate; lamivudine/zidovudine, a combination of nucleoside reverse transcriptase inhibitors (NRTIs); and ethinyloestradiol/levonorgestrel, a combination oral contraceptive. Methods Three randomized, double-blind, placebo-controlled studies were conducted in healthy subjects to assess the effect of maraviroc on pharmacokinetics of other drugs. Two, two-period crossover studies were conducted to assess (i) the effect of steady-state maraviroc (300 mg b.i.d.) on pharmacokinetics of midazolam; and (ii) the effect of steady-state maraviroc (300 mg b.i.d.) on the pharmacokinetics of lamivudine/zidovudine. A third two-way crossover study was conducted to evaluate the effect of steady-state maraviroc (100 mg b.i.d.) on the pharmacokinetics of 30 μg ethinyloestradiol/150 μg levonorgestrel (Microgynon®). Results The geometric mean ratios for Cmax and AUC for each of the compounds tested in the presence and absence of maraviroc were between 92% and 121%. There were no notable differences in Tmax, t1/2 or CLR (where measured) for any of the compounds. Conclusions Maraviroc had no clinically relevant effects on the pharmacokinetics of the CYP3A4 substrate midazolam, the NRTIs zidovudine/lamivudine, or the oral contraceptive steroids ethinyloestradiol and levonorgestrel. PMID:18333862

  7. Simultaneous Determination of Lamivudine, Zidovudine and Abacavir in Tablet Dosage Forms by RP HPLC Method

    Directory of Open Access Journals (Sweden)

    D. Anantha Kumar

    2010-01-01

    Full Text Available A simple, accurate and reproducible RP-HPLC method has been developed for the simultaneous determination of lamivudine, zidovudine and abacavir in tablet dosage forms. Chromatography was carried out on a HiQ Sil C 18 V column using a mobile phase consisting of 0.01 M potassium dihydrogen ortho-phosphate (pH 3.0 and methanol (55:45 v/v at a flow rate of 0.8 mL/min. The detection was made at 272 nm and stavudine was used as the internal standard for this study. The retention times for lamivudine, abacavir and zidovudine were found to be 3.8, 6.3, 8.1 min. respectively. The calibration curves were linear over the range 5-250 μg/mL for both zidovudine and abacavir and 5-140 μg/mL for lamivudine. The proposed method was validated as per ICH and USP guidelines and it was found suitable for the routine quality control analysis of the drugs in tablet dosage forms.

  8. Photolysis of three antiviral drugs acyclovir, zidovudine and lamivudine in surface freshwater and seawater.

    Science.gov (United States)

    Zhou, Chengzhi; Chen, Jingwen; Xie, Qing; Wei, Xiaoxuan; Zhang, Ya-nan; Fu, Zhiqiang

    2015-11-01

    Photodegradation is an important elimination process for many pharmaceuticals in surface waters. In this study, photodegradation of three antiviral drugs, acyclovir, zidovudine, and lamivudine, was investigated in pure water, freshwater, and seawater under the irradiation of simulated sunlight. Results showed that zidovudine was easily transformed via direct photolysis, while acyclovir and lamivudine were mainly transformed via indirect photolysis. We found that in freshwater, nitrate enhanced the photodegradation of the three antiviral drugs, bicarbonate promoted the photodegradation of acyclovir, and dissolved organic matter (DOM) accelerated the photolysis of acyclovir and lamivudine. In seawater, the photolysis of acyclovir was not susceptible to Cl(-), Br(-) and ionic strength; however, the photolysis of zidovudine was inhibited by Cl(-) and Br(-), and the photolysis of lamivudine was enhanced by Cl(-), Br(-) and ionic strength. Second-order reaction rate constants for the three antiviral drugs with (1)O2 (k1O2) and OH (kOH) were also measured. These results are important for fate and ecological risk assessment of the antiviral drugs in natural waters.

  9. Relationships between models of concurrency

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Sassone, Vladimiro; Winskel, Glynn

    1994-01-01

    Models for concurrency can be classified with respect to the three relevant parameters: behaviour/system, interleaving/noninterleaving, linear/branching time. When modelling a process, a choice concerning such parameters corresponds to choosing the level of abstraction of the resulting semantics....... The classifications are formalized through the medium of category theory....

  10. Concurrent Quantum Computation

    CERN Document Server

    Yamaguchi, F; Yamamoto, Y

    2000-01-01

    A quantum computer is a multi-particle interferometer that comprises beam splitters at both ends and arms, where the n two-level particles undergo the interactions among them. The arms are designed so that relevant functions required to produce a computational result is stored in the phase shifts of the 2^n arms. They can be detected by interferometry that allows us to utilize quantum parallelism. Quantum algorithms are accountable for what interferometers to be constructed to compute particular problems. A standard formalism for constructing the arms has been developed by the extension of classical reversible gate arrays. By its nature of sequential applications of logic operations, the required number of gates increases exponentially as the problem size grows. This may cause a crucial obstacle to perform a quantum computation within a limited decoherence time. We propose a direct and concurrent construction of the interferometer arms by one-time evolution of a physical system with arbitrary multi-particle i...

  11. Temporal Concurrent Constraint Programming

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Valencia Posso, Frank Dan

    2002-01-01

    The ntcc calculus is a model of non-deterministic temporal concurrent constraint programming. In this paper we study behavioral notions for this calculus. In the underlying computational model, concurrent constraint processes are executed in discrete time intervals. The behavioral notions studied...... reflect the reactive interactions between concurrent constraint processes and their environment, as well as internal interactions between individual processes. Relationships between the suggested notions are studied, and they are all proved to be decidable for a substantial fragment of the calculus...

  12. Separation Logic and Concurrency

    Science.gov (United States)

    Bornat, Richard

    Concurrent separation logic is a development of Hoare logic adapted to deal with pointers and concurrency. Since its inception, it has been enhanced with a treatment of permissions to enable sharing of data between threads, and a treatment of variables as resource alongside heap cells as resource. An introduction to the logic is given with several examples of proofs, culminating in a treatment of Simpson's 4-slot algorithm, an instance of racy non-blocking concurrency.

  13. Randomized, double-blind trial comparing indinavir alone, zidovudine alone and indinavir plus zidovudine in antiretroviral therapy-naive hiv-infected individuals with CD4 cell counts between 50 and 250/mm3

    Directory of Open Access Journals (Sweden)

    LEWI David S.

    2000-01-01

    Full Text Available Treatment with indinavir has been shown to result in marked decreases in viral load and increases in CD4 cell counts in HIV-infected individuals. A randomized double-blind study to evaluate the efficacy of indinavir alone (800 mg q8h, zidovidine alone (200 mg q8h or the combination was performed to evaluate progression to AIDS. 996 antiretroviral therapy-naive patients with CD4 cell counts of 50-250/mm3 were allocated to treatment. During the trial the protocol was amended to add lamivudine to the zidovudine-containing arms. The primary endpoint was time to development of an AIDS-defining illness or death. The study was terminated after a protocol-defined interim analysis demonstrated highly significant reductions in progression to a clinical event in the indinavir-containing arms, compared to the zidovudine arm (p<0.0001. Over a median follow-up of 52 weeks (up to 99 weeks, percent reductions in hazards for the indinavir plus zidovudine and indinavir groups compared to the zidovudine group were 70% and 61%, respectively. Significant reductions in HIV RNA and increases in CD4 cell counts were also seen in the indinavir-containing groups compared to the zidovudine group. Improvement in both CD4 cell count and HIV RNA were associated with reduced risk of disease progression. All three regimens were generally well tolerated.

  14. Incidence of lactic acidosis toxicity among patients on stavudine or zidovudine containing antiretroviral therapy at Lighthouse clinics

    Directory of Open Access Journals (Sweden)

    W Ng'ambi

    2012-11-01

    Full Text Available Although stavudine and zidovudine remain frequently used in low-income countries in Africa, they are associated with long-term toxicities. Lactic acidosis is one of the most serious toxicities in antiretroviral treatment (ART and occurs predominantly in regimens containing stavudine (D4T or zidovudine (AZT. We conducted this study to determine the incidence and risk factors for lactic acidosis among HIV-positive patients that have been on ART for at least 6 months. This study will bridge the gap that exists due to scarcity of data on the extent of toxicities due to long-term use of D4T and AZT. We conducted a retrospective cohort study using routine clinic data from the Lighthouse and Martin Preuss Centre electronic data systems. We used the clinic data collected between 1st January 2004 and 31st December 2011. We included into the analysis all patients that have been on D4T- or AZT-containing ARV drugs for at least 6 months. We analysed the data using Poisson regression of the number of cases of lactic acidosis (LA on gender, age at ART initiation, baseline BMI, and lipodystrophy in order to determine the incidence and risk factors for lactic acidosis. All statistical analyses were done at 5% significance level. We identified 14,854 patients that have ever been on D4T- or AZT-containing ARV drugs for longer than 5 months. Of these, 43% were male and median age was 34 years. The total number of cases of confirmed LA was 342 with observed mortality rate 40% more than the patients without confirmed LA. There were 23.02 cases of LA for every 1000 patient-years on D4T- or AZT-containing ART regimens. The strongest risk factor identified for developing LA was having a baseline BMI >25 with incidence rate ratio (IRR 3.11 (95% CI: 2.49, 3.88. The IRR for patients with a diagnosis of lipodystrophy was 1.77 (95% CI: 1.35, 2.32. Patients aged <30 years at ART initiation had 31% reduced risk of developing LA as compared to patients aged>39 years at ART

  15. Tolerance of a field grown soybean cultivar to elevated ozone level is concurrent with higher leaflet ascorbic acid level, higher ascorbate-dehydroascorbate redox status, and long term photosynthetic productivity.

    Science.gov (United States)

    Michael Robinson, J; Britz, S J

    2000-01-01

    We examined the characteristics of ascorbic acid (ASC) level, dehydroascorbate (DHA) level, and the ASC-DHA redox status in the leaflets of two soybean cultivars grown in a field environment and exposed to elevated ozone (O(3)) levels. These two cultivars, one that preliminary evidence indicated to be O(3)-tolerant (cv Essex), and one that was indicated to be O(3)-sensitive (cv Forrest), were grown in open-top chambers during the summer of 1997. The plants were exposed daily to a controlled, moderately high O(3) level ( approximately 58 nl l(-1) air) in the light, beginning at the seedling stage and continuing to bean maturity. Concurrently, control plants were exposed to carbon-filtered, ambient air containing a relatively low O(3) level ( approximately 24 nl l(-1) air) during the same period. Elevated O(3) did not affect biomass per plant, mature leaf area accretion, or bean yield per plant of cv Essex. In contrast, elevated O(3) level decreased the biomass and bean yield per plant of cv Forrest by approximately 20%. Daily leaflet photosynthesis rate and stomatal conductance per unit area did not decrease in either cultivar as a result of prolonged O(3) exposure. A 10% lower mature leaflet area in O(3)-treated cv Forrest plants contributed to an ultimate limitation in long-term photosynthetic productivity (vegetative and bean yield). Possible factors causing cv Essex to be more O(3) tolerant than cv Forrest were: 1) mature leaflets of control and O(3)-treated cv Essex plants consistently maintained a higher daily ASC level than leaflets of cv Forrest plants, and 2) mature leaflets of cv Essex plants maintained a higher daily ASC-DHA redox status than leaflets of cv Forrest plants.

  16. Concurrent Software Engineering Project

    Science.gov (United States)

    Stankovic, Nenad; Tillo, Tammam

    2009-01-01

    Concurrent engineering or overlapping activities is a business strategy for schedule compression on large development projects. Design parameters and tasks from every aspect of a product's development process and their interdependencies are overlapped and worked on in parallel. Concurrent engineering suffers from negative effects such as excessive…

  17. Temporal Concurrent Constraint Programming

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Palamidessi, Catuscia; Valencia, Frank Dan

    2002-01-01

    The ntcc calculus is a model of non-deterministic temporal concurrent constraint programming. In this paper we study behavioral notions for this calculus. In the underlying computational model, concurrent constraint processes are executed in discrete time intervals. The behavioral notions studied...

  18. Concurrent Software Engineering Project

    Science.gov (United States)

    Stankovic, Nenad; Tillo, Tammam

    2009-01-01

    Concurrent engineering or overlapping activities is a business strategy for schedule compression on large development projects. Design parameters and tasks from every aspect of a product's development process and their interdependencies are overlapped and worked on in parallel. Concurrent engineering suffers from negative effects such as excessive…

  19. Probabilistic Concurrent Kleene Algebra

    Directory of Open Access Journals (Sweden)

    Annabelle McIver

    2013-06-01

    Full Text Available We provide an extension of concurrent Kleene algebras to account for probabilistic properties. The algebra yields a unified framework containing nondeterminism, concurrency and probability and is sound with respect to the set of probabilistic automata modulo probabilistic simulation. We use the resulting algebra to generalise the algebraic formulation of a variant of Jones' rely/guarantee calculus.

  20. Impredicative concurrent abstract predicates

    DEFF Research Database (Denmark)

    Svendsen, Kasper; Birkedal, Lars

    2014-01-01

    We present impredicative concurrent abstract predicates { iCAP { a program logic for modular reasoning about concurrent, higher- order, reentrant, imperative code. Building on earlier work, iCAP uses protocols to reason about shared mutable state. A key novel feature of iCAP is the ability to dene...

  1. Alternating treatment with didanosine and zidovudine versus either drug alone for the treatment of advanced HIV infection. The Alter Study. Nordic HIV Therapy Group

    DEFF Research Database (Denmark)

    Gerstoft, J; Melander, H; Bruun, J N;

    1997-01-01

    The efficacy and safety of an alternating regime with zidovudine and didanosine versus treatment with either drug alone were investigated in a randomized, open, controlled trial, 552 patients with advanced HIV infection, 47% of whom had received prior treatment with zidovudine, were enrolled...

  2. Concurrent Aerobic and Resistance Training Has Anti-Inflammatory Effects and Increases Both Plasma and Leukocyte Levels of IGF-1 in Late Middle-Aged Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Giosuè Annibalini

    2017-01-01

    Full Text Available Type 2 diabetes (T2D is an age-related chronic disease associated with metabolic dysregulation, chronic inflammation, and activation of peripheral blood mononuclear cells (PBMC. The aim of this study was to assess the effects of a concurrent exercise training program on inflammatory status and metabolic parameters of T2D patients. Sixteen male patients (age range 55–70 were randomly assigned to an intervention group (n=8, which underwent a concurrent aerobic and resistance training program (3 times a week; 16 weeks, or to a control group, which followed physicians’ usual diabetes care advices. Training intervention significantly improved patients’ body composition, blood pressure, total cholesterol, and overall fitness level. After training, plasma levels of adipokines leptin (−33.9% and RBP4 (−21.3%, and proinflammatory markers IL-6 (−25.3%, TNF-α (−19.8% and MCP-1 (−15.3% decreased, whereas anabolic hormone IGF-1 level increased (+16.4%. All improvements were significantly greater than those of control patients. Plasma proteomic profile of exercised patients showed a reduction of immunoglobulin K light chain and fibrinogen as well. Training also induced a modulation of IL-6, IGF-1, and IGFBP-3 mRNAs in the PBMCs. These findings confirm that concurrent aerobic and resistance training improves T2D-related metabolic abnormalities and has the potential to reduce the deleterious health effects of diabetes-related inflammation.

  3. Specification of Concurrent Objects

    DEFF Research Database (Denmark)

    Sørensen, Morten U.

    relation over two objects and an event. In the model, objects can be composed by parallel composition, encapsulation, and hiding of operations. Refinement between objects is defined as fair trace inclusion.A specification language is presented where objects can be specified operationally by abstract......Concurrent objects are named concurrent processes that interact by invoking each other's operations. We describe how such concurrent objects can be specified, how objects can be composed, and how it can be shown that one object refines another.First a model is defined, based on a transition...

  4. Resistance detected by pyrosequencing following zidovudine-monotherapy for prevention of HIV-1 mother-to-child-transmission

    Science.gov (United States)

    Olson, Scott C.; Ngo-Giang-Huong, Nicole; Beck, Ingrid; Deng, Wenjie; Britto, Paula; Shapiro, David E.; Bumgarner, Roger E.; Mullins, James I.; Van Dyke, Russell B.; Jourdain, Gonzague; Frenkel, Lisa M.

    2015-01-01

    To prevent mother-to-child-transmission-of-HIV-1, the 2010 WHO guidelines recommended prenatal zidovudine monotherapy (Option A). To determine if ZDV-monotherapy selects for HIV-resistance in antiretroviral-naïve women during pregnancy, specimens from 50 were examined using pyrosequencing. ZDV-resistance mutations were detected at delivery in 7 (14%, 95% confidence interval 6.6-26.5%). These data raise the question whether women administered zidovudine monotherapy for PMTCT could have higher risk of virologic failure when later started on combination ARV therapy, as has been demonstrated following single-dose-nevirapine prophylaxis. PMID:26244386

  5. Concurrent bisimulation algorithm

    OpenAIRE

    Kułakowski, Konrad

    2013-01-01

    The coarsest bisimulation-finding problem plays an important role in the formal analysis of concurrent systems. For example, solving this problem allows the behavior of different processes to be compared or specifications to be verified. Hence, in this paper an efficient concurrent bisimulation algorithm is presented. It is based on the sequential Paige and Tarjan algorithm and the concept of the state signatures. The original solution follows Hopcroft's principle "process the smaller half". ...

  6. Data refinement for true concurrency

    Directory of Open Access Journals (Sweden)

    Brijesh Dongol

    2013-05-01

    Full Text Available The majority of modern systems exhibit sophisticated concurrent behaviour, where several system components modify and observe the system state with fine-grained atomicity. Many systems (e.g., multi-core processors, real-time controllers also exhibit truly concurrent behaviour, where multiple events can occur simultaneously. This paper presents data refinement defined in terms of an interval-based framework, which includes high-level operators that capture non-deterministic expression evaluation. By modifying the type of an interval, our theory may be specialised to cover data refinement of both discrete and continuous systems. We present an interval-based encoding of forward simulation, then prove that our forward simulation rule is sound with respect to our data refinement definition. A number of rules for decomposing forward simulation proofs over both sequential and parallel composition are developed.

  7. Adherence to combined Lamivudine + Zidovudine versus individual components: a community-based retrospective medicaid claims analysis.

    Science.gov (United States)

    Legorreta, A; Yu, A; Chernicoff, H; Gilmore, A; Jordan, J; Rosenzweig, J C

    2005-11-01

    Adherence to a fixed dose combination of dual nucleoside antiretroviral therapy was compared between human immunodeficiency virus (HIV)-infected patients newly started on a fixed dosed combination of lamivudine (3TC) 150 mg/zidovudine (ZDV) 300 mg versus its components taken as separate pills. Medicaid pharmacy claims data were used for analyses. To examine the association between treatment group and medication adherence, three types of multivariate regressions were employed. In addition, all regressions were conducted for the whole population using data from 1995 to 2001 as well as a subpopulation, which excluded data prior to September 1997. Model covariates included patient characteristics, healthcare utilization, and non-study antiretroviral therapy use. The likelihood of > or =95% adherence among patients on combination therapy was three times greater than patients taking 3TC and ZDV in separate pills. Also, combination therapy patients had on average 1.4 fewer adherence failures per year of follow-up and nearly double the time to adherence failure compared to the separate pills group. Consistency among study results suggests that fixed dose combination therapies such as lamivudine (3TC) 150 mg/ zidovudine (ZDV) 300 mg should be considered when prescribing HIV treatment that includes an appropriate dual nucleoside.

  8. Formulation and evaluation of Zidovudine loaded chitosan Microspheres for controlled release

    Directory of Open Access Journals (Sweden)

    Kesari Asha

    2012-03-01

    Full Text Available The aim of this study was to formulate and evaluate zidovudine loaded chitosan microspheres for controlled drug release. Microspheres were prepared by emulsification method using gluteraldehyde as crosslinking agent. The prepared microspheres were characterized for their yield and drug loading, as well by Fourier transform infrared spectroscopy (FTIR, X-ray powder diffractometry and Scanning electron microscopy. The in vitro release studies were performed in pH 7.4, phosphate buffer. The prepared microspheres were free flowing and spherical in shape. The drugloaded microspheres showed 72-94% of entrapment and release was extended up to 12h. The infrared spectra showed stable character of zidovudine in the drugloaded microspheres and revealed the absence of drugpolymer interactions. X-ray diffraction patterns showed that there was decrease in crystallinity of the drug. Scanning electron microscopy study revealed that the microspheres were spherical and porous in nature. It was found that the drug: polymer ratio, the stirring speed, the concentration of surfactant, and the amount of gluteraldehyde used for crosslinking were the most significant variables which influenced the size of the chitosan microspheres under the applied experimental condition.

  9. Automatic and Hierarchical Verification for Concurrent Systems

    Institute of Scientific and Technical Information of China (English)

    赵旭东; 冯玉琳

    1990-01-01

    Proving correctness of concurrent systems is quite difficult because of the high level of nondeterminism,especially in large and complex ones.AMC is a model checking system for verifying asynchronous concurrent systems by using branching time temporal logic.This paper introduces the techniques of the modelling approach,especially how to construct models for large concurrent systems with the concept of hierarchy,which has been proved to be effective and practical in verifying large systems without a large growth of cost.

  10. Risk of zidovudine-induced anemia on human immunodeficiency virus (HIV infection patients with different CD4 cell counts

    Directory of Open Access Journals (Sweden)

    anak agung ayu niti wedayani

    2017-02-01

    Full Text Available Anemia is the most common hematologic abnormality in patients with human immunodeficiency virus (HIV infection. This abnormality is associated with HIV infection itself, HIV-related opportunities infections or drug use. Zidovudine (AZT is the most common cause of anemia in HIV patients. Recent study showed anemia in HIV patients is also associated with CD4 cell counts. Aim of this study was to evaluate the risk of anemia on HIV patients with different CD4 cell counts after AZT-based antiretroviral therapy (ART.This retrospective cohort study was conducted using medical record of HIV patients in Dr. Soetomo General Hospital, Surabaya. Subjects who fulfilled the inclusion and exclusion criteria were divided into two group i.e. HIV patients with CD4 cell counts 200-350 cell/mm3 and those with CD4cell counts ≥350 cell/mm3. All available demographics, clinical and laboratory data of subjects before and after AZT-based ART were then recorded and evaluated. Ninety-seven HIV patients (50 male and 47 female were involved in this study. The result showed that the anemia incidence significantly increased after AZT-based ART (p0.05. Gender, age, weight and clinical stage were not associated with anemia incidence (p>0.05. In contrast, anemia incidence is associated with Hb level before AZT therapy (p<0.05. In conclusion, the anemia incidence in HIV patients after AZT based ART is not associated with the level of CD4 cell counts, however it is associated with Hb levels before AZT therapy.

  11. Characterizing Distributed Concurrent Engineering Teams: A Descriptive Framework for Aerospace Concurrent Engineering Design Teams

    Science.gov (United States)

    Chattopadhyay, Debarati; Hihn, Jairus; Warfield, Keith

    2011-01-01

    As aerospace missions grow larger and more technically complex in the face of ever tighter budgets, it will become increasingly important to use concurrent engineering methods in the development of early conceptual designs because of their ability to facilitate rapid assessments and trades in a cost-efficient manner. To successfully accomplish these complex missions with limited funding, it is also essential to effectively leverage the strengths of individuals and teams across government, industry, academia, and international agencies by increased cooperation between organizations. As a result, the existing concurrent engineering teams will need to increasingly engage in distributed collaborative concurrent design. This paper is an extension of a recent white paper written by the Concurrent Engineering Working Group, which details the unique challenges of distributed collaborative concurrent engineering. This paper includes a short history of aerospace concurrent engineering, and defines the terms 'concurrent', 'collaborative' and 'distributed' in the context of aerospace concurrent engineering. In addition, a model for the levels of complexity of concurrent engineering teams is presented to provide a way to conceptualize information and data flow within these types of teams.

  12. Study on the interaction of the antiviral drug, zidovudine with DNA using neutral red (NR) and methylene blue (MB) dyes

    Energy Technology Data Exchange (ETDEWEB)

    Shahabadi, Nahid, E-mail: nahidshahabadi@yahoo.com [Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Moghadam, Neda Hossein pour [Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of)

    2013-02-15

    The interaction between the drug, zidovudine and calf thymus DNA (CT-DNA) in physiological buffer (pH 7.4) was investigated using neutral red (NR) and methylene blue (MB) dyes as a spectral probes by UV-vis absorption and fluorescence spectroscopy, as well as circular dichroism (CD) spectroscopy. The experimental results showed that the conformational changes in DNA helix induced by zidovudine are the reason for the fluorescence quenching of the DNA-NR system. In addition, by increasing zidovudine to DNA-MB solution, the fluorescence has no change. From the experimental results, it was found that zidovudine can cause structural changes on CT-DNA and bind with DNA via groove binding mode. At the same time, the paper proved that conformational changes of DNA can also lead to the fluorescence decrease of DNA-probe systems. - Highlights: Black-Right-Pointing-Pointer Search for new molecular structures which exhibit effective antitumor activities among popular drugs. Black-Right-Pointing-Pointer The DRUG can bind to DNA via groove binding mode. Black-Right-Pointing-Pointer Several spectroscopic techniques have been used in this research.

  13. Metabolic syndrome in patients on first-line antiretroviral therapy containing zidovudine or tenofovir in rural Lesotho, Southern Africa.

    Science.gov (United States)

    Labhardt, Niklaus Daniel; Müller, Urs Franz; Ringera, Isaac; Ehmer, Jochen; Motlatsi, Mokete M; Pfeiffer, Karolin; Hobbins, Michael A; Muhairwe, Josephine A; Muser, Juergen; Hatz, Christoph

    2017-06-01

    To assess the prevalence of metabolic syndrome (MetS) among patients in rural Lesotho who are taking first-line antiretroviral therapy (ART) containing either zidovudine or tenofovir disoproxil. Cross-sectional survey in 10 facilities in Lesotho among adult (≥16 years) patients on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based first-line ART for ≥6 months. MetS was defined according to the International Diabetes Federation criteria. Among 1166 patients (65.8% female), 22.2% (95% CI: 19.3-25.3) of women and 6.3% (4.1-9.1) of men met the IDF definition of MetS (P < 0.001). In both sexes, there was no significant difference in MetS prevalence between NNRTIs. However, in women taking zidovudine as nucleoside reverse transcriptase inhibitor (NRTI), MetS prevalence was 27.9%, vs. 18.8% in those taking tenofovir. In the multivariate logistic regression allowing for socio-demographic and clinical covariates, ART containing zidovudine was associated with MetS in women (aOR 2.17 (1.46-3.22), P < 0.001) but not in men. In this study, taking ART containing zidovudine instead of tenofovir disoproxil was an independent predictor of MetS in women but not in men. This finding endorses WHO's recommendation of tenofovir as preferred NRTI. © 2017 John Wiley & Sons Ltd.

  14. Channel's Concurrence and Quantum Teleportation

    Institute of Scientific and Technical Information of China (English)

    LING Yin-Sheng

    2005-01-01

    Concurrence can measure the entanglement property of a system. If the channel is a pure state, positive concurrence state can afford the good performance in the teleportation process. If the channel ia a mixed state, positive concurrence state cannot assure the good performance in the teleportation. The conditions of the positive concurrence and the quantum teleportation in the Heisenberg spin ring is derived.

  15. Concurrent Therapy with a Low-carbohydrate Diet and Miglitol Remarkably Improved the Postprandial Blood Glucose and Insulin Levels in a Patient with Reactive Hypoglycemia due to Late Dumping Syndrome.

    Science.gov (United States)

    Hirose, Sachie; Iwahashi, Yasuyuki; Seo, Akane; Sumiyoshi, Michitaka; Takahashi, Tetsuya; Tamori, Yoshikazu

    2016-01-01

    Reactive hypoglycemia induced by late dumping syndrome is often observed after gastrectomy. However, no effective therapy has yet been fully established. We herein describe a case in which concurrent therapy with a low-carbohydrate diet using low-glycemic-index food and an alpha-glucosidase inhibitor, miglitol, very effectively ameliorated the postprandial fluctuations in the blood glucose and plasma insulin levels in a patient with reactive hypoglycemia due to late dumping syndrome following total gastrectomy. The administration of miglitol under a low-carbohydrate diet using low-glycemic-index food may therefore be an ideal treatment for reactive hypoglycemia due to late dumping syndrome.

  16. Coalgebra, concurrency and control

    NARCIS (Netherlands)

    J.J.M.M. Rutten (Jan)

    1999-01-01

    textabstractCoalgebra is used to generalize notions and techniques from concurrency theory, in order to apply them to problems concerning the supervisory control of discrete event systems. The main ingredients of this approach are the characterization of controllability in terms of (a variant of)

  17. Morse Theory and Concurrency

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2003-01-01

    The work is intended to provide some insight about concurrency theory using ideas from geometry and algebraic topology. We define a topological space containing all traces of execution of the computer program and the information about how time flows. This is the main difference with standard...

  18. Composing Concurrent Objects

    NARCIS (Netherlands)

    Bergmans, Lodewijk

    1994-01-01

    Adopting the object-oriented paradigm for the development of large and complex software systems offers several advantages, of which increased extensibility and reusability are the most prominent ones. The object-oriented model is also quite suitable for modelling concurrent systems. However, it

  19. Simultaneous determination of the HIV nucleoside analogue reverse transcriptase inhibitors lamivudine, didanosine, stavudine, zidovudine and abacavir in human plasma by reversed phase high performance liquid chromatography.

    NARCIS (Netherlands)

    Verweij-van Wissen, C.P.W.G.M.; Aarnoutse, R.E.; Burger, D.M.

    2005-01-01

    A reversed phase high performance liquid chromatography method was developed for the simultaneous quantitative determination of the nucleoside reverse transcriptase inhibitors (NRTIs) lamivudine, didanosine, stavudine, zidovudine and abacavir in plasma. The method involved solid-phase extraction wit

  20. Synthesis improvement of zidovudine%齐多夫定合成工艺改进

    Institute of Scientific and Technical Information of China (English)

    余勇; 刘骞峰; 杨永忠; 徐云侠; 吴生秀

    2011-01-01

    β-Thymidine was used as the starting material. Oxygen bridge compound was formed via mitsuobureaction from 5' -primary hydroxyl protected by p-methoxy benzoic acid in DEAD/PPh3 system. The zidovu-dine was obtained via azide reaction between oxygen bridge compound and sodium azide. The total yield was62%.%以β-胸苷为起始原料,5’-伯羟基采用对甲氧基苯甲酸保护,并在DEAD/PPh3体系中经过mitsuobu反应形成氧桥化合物,再与叠氮化钠发生叠氮化反应,最后脱对甲氧基苯甲酸保护基后获得目标产物齐多夫定,总收率62%.

  1. Zidovudine Injection

    Science.gov (United States)

    ... severe side effects, such as liver damage, blood toxicities, and muscle disorders. If you experience any of ... prescription and nonprescription medications you are taking, especially acetaminophen, acyclovir (Zovirax), aspirin, cancer chemotherapy, cimetidine (Tagamet), fluconazole ( ...

  2. Ultrastructural characteristics and DNA immunocytochemistry in human immunodeficiency virus and zidovudine-associated myopathies.

    Science.gov (United States)

    Pezeshkpour, G; Illa, I; Dalakas, M C

    1991-12-01

    Electron microscopic features of muscle biopsies from 13 human immunodeficiency (HIV)-positive patients who had myopathy while receiving zidovudine (AZT) were compared with biopsies from five patients with HIV-induced myopathy who were not treated with AZT. All specimens showed disorganization of the myofibrillar structures, along with a varying degree of nemaline (rod) bodies, vacuolization, inflammation, and endothelial tubuloreticular profiles. One untreated and all AZT-treated patients had cytoplasmic bodies, which in the latter were abundant, large, and irregular. Two untreated patients had a peculiar osmiophilic destruction of the muscle fibers, with numerous tubuloreticular profiles in the endothelial cells and brisk inflammation that included lymphoplasmatoid cells. The AZT-treated group had ubiquitous abnormal mitochondria that complemented the presence of ragged red fibers seen by light microscopy. There was subsarcolemmal proliferation of mitochondria, with marked variation in size and shape and proliferation or disorganization of their cristae. Paracrystalline inclusions were seen in one patient. Blind re-examination of the electron micrographs showed abnormal mitochondria that readily distinguished patients with AZT-associated myopathy from those with untreated HIV-induced myopathy. Immunocytochemistry using antibodies to single- and double-stranded DNA revealed severe reduction of mitochondrial DNA compared with the normal nuclear DNA. Although the myopathies associated with HIV and AZT share common myopathologic features, the mitochondrial abnormalities are unique to the AZT-treated patients. Since mitochondrial DNA is specifically reduced, the structural changes noted on electron microscopy are probably associated with mitochondrial dysfunction. Zidovudine, a DNA chain terminator that inhibits the mitochondrial gamma-DNA polymerase, is toxic to muscle mitochondria.

  3. Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

    Directory of Open Access Journals (Sweden)

    André Bersani Dezani

    2013-12-01

    Full Text Available Solubility and dissolution rate of drugs are of major importance in pre-formulation studies of pharmaceutical dosage forms. The solubility improvement allows the drugs to be potential biowaiver candidates and may be a good way to develop more dose-efficient formulations. Solubility behaviour of lamivudine, stavudine and zidovudine in individual solvents (under pH range of 1.2 to 7.5 was studied by equilibrium solubility and intrinsic dissolution methods. In solubility study by equilibrium method (shake-flask technique, known amounts of drug were added in each media until to reach saturation and the mixture was subjected to agitation of 150 rpm for 72 hours at 37 ºC. In intrinsic dissolution test, known amount of each drug was compressed in the matrix of Wood's apparatus and subjected to dissolution in each media with agitation of 50 rpm at 37 ºC. In solubility by equilibrium method, lamivudine and zidovudine can be considered as highly soluble drugs. Although stavudine present high solubility in pH 4.5, 6.8, 7.5 and water, the solubility determination in pH 1.2 was not possible due stability problems. Regarding to intrinsic dissolution, lamivudine and stavudine present high speed of dissolution. Considering a boundary value presented by Yu and colleagues (2004, all drugs studied present high solubility characteristics in intrinsic dissolution method. Based on the obtained results, intrinsic dissolution seems to be superior for solubility studies as an alternative method for biopharmaceutical classification purposes.

  4. A Concurrent Logical Relation

    DEFF Research Database (Denmark)

    Birkedal, Lars; Sieczkowski, Filip; Thamsborg, Jacob Junker

    2012-01-01

    We present a logical relation for showing the correctness of program transformations based on a new type-and-effect system for a concurrent extension of an ML-like language with higher-order functions, higher-order store and dynamic memory allocation. We show how to use our model to verify a number...... of interesting program transformations that rely on effect annotations. In particular, we prove a Parallelization Theorem, which expresses when it is sound to run two expressions in parallel instead of sequentially. The conditions are expressed solely in terms of the types and effects of the expressions....... To the best of our knowledge, this is the first such result for a concurrent higher-order language with higher-order store and dynamic memory allocation....

  5. Algebraic topology and concurrency

    DEFF Research Database (Denmark)

    Fajstrup, Lisbeth; Raussen, Martin; Goubault, Eric

    2006-01-01

    We show in this article that some concepts from homotopy theory, in algebraic topology,are relevant for studying concurrent programs. We exhibit a natural semantics of semaphore programs, based on partially ordered topological spaces, which are studied up to “elastic deformation” or homotopy......, giving information about important properties of the program, such as deadlocks, unreachables, serializability, essential schedules, etc. In fact, it is not quite ordinary homotopy that has to be used, but rather a “directed homotopy” that does not reverse the flow of time. We show some of the essential...... differences between ordinary and directed homotopy through examples. We also relate the topological view to a combinatorial view of concurrent programs closer to transition systems, through the notion of a cubical set. Finally we apply some of these concepts to the proof of the safeness of a two...

  6. Morse Theory and Concurrency

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2003-01-01

    The work is intended to provide some insight about concurrency theory using ideas from geometry and algebraic topology. We define a topological space containing all traces of execution of the computer program and the information about how time flows. This is the main difference with standard...... with piecewise-smooth boundary. Our aim is to identify the equivalence classes with the critical points of a certain Morse function....

  7. Morse Theory and Concurrency

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2003-01-01

    The work is intended to provide some insight about concurrency theory using ideas from geometry and algebraic topology. We define a topological space containing all traces of execution of the computer program and the information about how time flows. This is the main difference with standard...... with piecewise-smooth boundary. Our aim is to identify the equivalence classes with the critical points of a certain Morse function....

  8. Feature conversion for concurrent engineering

    NARCIS (Netherlands)

    De Kraker, J.K.

    1998-01-01

    Feature conversion for concurrent engineering integrates two modern product development paradigms. Concurrent engineering is a product development paradigm in which multiple engineering disciplines participate. It optimizes a product with respect to available resources and product quality, for which

  9. Risk of zidovudine-induced anemia on human immunodeficiency virus (HIV) infection patients with different CD4 cell counts

    OpenAIRE

    wedayani, anak agung ayu niti; Sholikhah, Eti Nurwening; Kristin, Erna; Triyono, Erwin Astha

    2017-01-01

    Anemia is the most common hematologic abnormality in patients with human immunodeficiency virus (HIV) infection. This abnormality is associated with HIV infection itself, HIV-related opportunities infections or drug use. Zidovudine (AZT) is the most common cause of anemia in HIV patients. Recent study showed anemia in HIV patients is also associated with CD4 cell counts. Aim of this study was to evaluate the risk of anemia on HIV patients with different CD4 cell counts after AZT-based antiret...

  10. Preparation and in vitro dissolution profile of zidovudine loaded microspheres made of Eudragit RS 100, RL 100 and their combinations.

    Science.gov (United States)

    Nath, Bipul; Nath, Lila Kanta; Kumar, Pradeep

    2011-01-01

    The objective of present investigation was to evaluate the entrapment efficiency of the anti-HIV drug, zidovudine, using two Eudragit polymers of different permeability characteristics and to study the effect of this entrapment on the drug release properties. In order to increase the entrapment efficiency optimum concentration of polymer solutions were prepared in acetone using magnesium stearate as droplet stabilizer. The morphology of the microspheres was evaluated using a scanning electron microscope, which showed a spherical shape with smooth surface. The mean sphere diameter was between 1000-3000 microm and the entrapment efficiencies ranged from 56.4-87.1%. Polymers were used separately and in combination to prepare different microspheres. The prepared microspheres were studied for drug release behavior in phosphate buffer at pH 7.4, because the Eudragit polymers are independent of the pH of the dissolution medium. The release profiles and entrapment efficiencies depended strongly on the structure of the polymers used as wall materials. The release rate of zidovudine from Eudragit RS 100 microspheres was much lower than that from Eudragit RL 100 microspheres. Evaluation of release data reveals that release of zidovudine from Eudragit RL 100 microspheres followed the Higuchi rule, whereas Eudragit RS 100 microspheres exhibited an initial burst release, a lag period for entry of surrounding dissolution medium into polymer matrix and finally, diffusion of drug through the wall material.

  11. Morse Theory and Concurrency

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2003-01-01

    The work is intended to provide some insight about concurrency theory using ideas from geometry and algebraic topology. We define a topological space containing all traces of execution of the computer program and the information about how time flows. This is the main difference with standard...... topological reasoning in which there is no information about relation "in time" among points. The main task is to define equivalence of paths reflecting execution of a program. We use the notion of homotopy history equivalence relation. The model space considered in this work is a differentiable manifold...

  12. Mastering concurrency in Go

    CERN Document Server

    Kozyra, Nathan

    2014-01-01

    A practical approach covering everything you need to know to get up and running with Go, starting with the basics and imparting increasingly more detail as the examples and topics become more complicated. The book utilizes a casual, conversational style, rife with actual code and historical anecdotes for perspective, as well as usable and extensible example applications. This book is intended for systems developers and programmers with some experience in either Go and/or concurrent programming who wish to become fluent in building high-performance applications that scale by leveraging single-c

  13. Preparing HEP software for concurrency

    Science.gov (United States)

    Clemencic, M.; Hegner, B.; Mato, P.; Piparo, D.

    2014-06-01

    The necessity for thread-safe experiment software has recently become very evident, largely driven by the evolution of CPU architectures towards exploiting increasing levels of parallelism. For high-energy physics this represents a real paradigm shift, as concurrent programming was previously only limited to special, well-defined domains like control software or software framework internals. This paradigm shift, however, falls into the middle of the successful LHC programme and many million lines of code have already been written without the need for parallel execution in mind. In this paper we have a closer look at the offline processing applications of the LHC experiments and their readiness for the many-core era. We review how previous design choices impact the move to concurrent programming. We present our findings on transforming parts of the LHC experiment reconstruction software to thread-safe code, and the main design patterns that have emerged during the process. A plethora of parallel-programming patterns are well known outside the HEP community, but only a few have turned out to be straightforward enough to be suited for non-expert physics programmers. Finally, we propose a potential strategy for the migration of existing HEP experiment software to the many-core era.

  14. Recursive Concurrent Stochastic Games

    CERN Document Server

    Etessami, Kousha

    2008-01-01

    We study Recursive Concurrent Stochastic Games (RCSGs), extending our recent analysis of recursive simple stochastic games [16,17] to a concurrent setting where the two players choose moves simultaneously and independently at each state. For multi-exit games, our earlier work already showed undecidability for basic questions like termination, thus we focus on the important case of single-exit RCSGs (1-RCSGs). We first characterize the value of a 1-RCSG termination game as the least fixed point solution of a system of nonlinear minimax functional equations, and use it to show PSPACE decidability for the quantitative termination problem. We then give a strategy improvement technique, which we use to show that player 1 (maximizer) has \\epsilon-optimal randomized Stackless & Memoryless (r-SM) strategies for all \\epsilon > 0, while player 2 (minimizer) has optimal r-SM strategies. Thus, such games are r-SM-determined. These results mirror and generalize in a strong sense the randomized memoryless determinacy r...

  15. Concurrent improvement of the metabolic syndrome and lower urinary tract symptoms upon normalisation of plasma testosterone levels in hypogonadal elderly men.

    Science.gov (United States)

    Haider, A; Gooren, L J; Padungtod, P; Saad, F

    2009-02-01

    Central obesity in adulthood, the metabolic syndrome, erectile failure and lower urinary tract symptoms (LUTS) are all associated with lower-than-normal testosterone levels, although the relationship between testosterone and LUTS appears weak. The metabolic syndrome is associated with an overactivity of the autonomic nervous system. Alternatively, the metabolic syndrome is associated with markers of inflammation, such as C-reactive protein (CRP), maybe signalling intraprostatic inflammation. A large cohort of 95 middle-aged to elderly hypogonadal men (T levels 5.9-12.1 nmol l(-1)) were treated with parenteral testosterone undecanoate and its effects on the metabolic syndrome {waist circumference, cholesterol, CRP and LUTS [residual bladder volume (RBV), International Prostate Symptoms Score (IPSS), prostate volume, prostate-specific antigen (PSA)]} were evaluated. Along with the improvements of the metabolic syndrome, there was a significant decline of the values of the IPSS, RBV and CRP. There was a (low) level of correlation between the decline of waist circumference and residual volume of urine but not with IPSS and prostate size. Along with the improvement of the metabolic syndrome upon testosterone administration, there was also an improvement of the IPSS and of RBV of urine and CRP. The mechanism remains to be elucidated.

  16. The influence of CD 4+t cells, hiv disease stage and zidovudine on hiv isolation in Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Brites

    1996-02-01

    Full Text Available HIV-l isolation was attempted on 72 individuais, including persons with knoum HIV infection and five without proven HIV infection but with indeterminate Western blot patterns, as well as on low-risk HIV seronegative persons. The ahility to detect HIV- 1 frorn culture supernatant by p24 antigen capture assay was evaluated by segregating patients by absolute CD4+ cell counts, clinicai stage of disease, p24 antigenemia and zidovudine use. The likelihood of a p24 positive HIV culture was highest among patients with CD4+ T-cell counts below 200/ul and patients with advanced clinical disease. Use of zidovudine did not affect the rate ofHIV positwity in cultures.Tentativa de isolamento do vírus tipo 1 da imunodeficiência adquirida (VIH-1 foi realizada em 72 indivíduos sendo 51 pacientes com sorologia positiva para o VIH-1, confirmada por Western blot; 5 doadores de sangue com padrão indeterminado ao Western blot; 3 indivíduos com diagnóstico clínico de AIDS, porém com sorologia negativa, e 13 profissionais de saúde soronegativos. Os pacientes foram estratificados de acordo com a contagem de células CD4+, estágio clínico , antigenemia (p24 e uso de zidovudine. As culturas para o VIH-1 foram positivas em 45/50 (90% tentativas. Houve uma correlação inversa entre o número de células CD4+ e a freqüência de isolamento do VIH-1. As culturas foram positivas em 84% dos indivíduos com CD4+ <200, contra 48% d positividade naqueles com contagem de célula CD4+ acima deste valor. O uso de zidovudine não interferiu na positividade das culturas. Concluímo. que a sensibilidade dos métodos de culture qualitativo e quantitativo é similar para a detecção do VIH-1. A taxa de positividade das culturas não foi afetada pelo uso prévio de zidovudine, mas foi diretamente proporcional ao grau de imunodeficiência dos pacientes.

  17. Models for concurrency: towards a classification

    DEFF Research Database (Denmark)

    Sassone, Vladimiro; Nielsen, Mogens; Winskel, Glynn

    1996-01-01

    Models for concurrency can be classified with respect to three relevant parameters: behaviour/ system, interleaving/noninterleaving, linear/branching time. When modelling a process, a choice concerning such parameters corresponds to choosing the level of abstraction of the resulting semantics....... In this paper, we move a step towards a classification of models for concurrency based on the parameters above. Formally, we choose a representative of any of the eight classes of models obtained by varying the three parameters, and we study the formal relationships between them using the language of category...

  18. Authentic And Concurrent Evaluation-refining

    DEFF Research Database (Denmark)

    Eriksson, Carina Ihlström; Åkesson, Maria; Kautz, Karlheinz

    2011-01-01

    This paper addresses the need for more detailed accounts for evaluation in design science research literature. By revisiting a design project regarding the future e-newspaper we give detailed descriptions of its authentic and concurrent evaluation approach by illustrating the what, why and how...... as well as decisions on strategic levels. We emphasize a holistic and concurrent approach to evaluation compared to the general design science research thinking and argue that reflecting on how to seek authenticity is important. By authenticity we refer to the notion of how closely an evaluation captures...

  19. Modeling disease spread in populations with birth, death, and concurrency

    CERN Document Server

    Millera, Joel C

    2016-01-01

    The existence of sexual partnerships that overlap in time (concurrent relationships) is believed by some to be a significant contributing factor to the spread of HIV, although this is controversial. We derive an analytic model which allows us to investigate and compare disease spread in populations with and without concurrency. We can identify regions of parameter space in which its impact is negligible, and other regions in which it plays a major role. We also see that the impact of concurrency on the initial growth phase can be much larger than its impact on the equilibrium size. We see that the effect of concurrency saturates, which leads to the perhaps surprising conclusion that interventions targeting concurrency may be most effective in populations with low to moderate levels of concurrency.

  20. Domain Theory for Concurrency

    DEFF Research Database (Denmark)

    Nygaard, Mikkel

    a process is capable. HOPLA can directly encode calculi like CCS, CCS with process passing, and mobile ambients with public names, and it can be given a straightforward operational semantics supporting a standard bisimulation congruence. The denotational and operational semantics are related with simple...... and associated comonads, it highlights the role of linearity in concurrent computation. Two choices of comonad yield two expressive metalanguages for higher-order processes, both arising from canonical constructions in the model. Their denotational semantics are fully abstract with respect to contextual...... input necessary for it. Such a semantics is provided, based on event structures; it agrees with the presheaf semantics at first order and exposes the tensor operation as a simple parallel composition of event structures. The categorical model obtained from presheaves is very rich in structure and points...

  1. Concurrent engineering research center

    Science.gov (United States)

    Callahan, John R.

    1995-01-01

    The projects undertaken by The Concurrent Engineering Research Center (CERC) at West Virginia University are reported and summarized. CERC's participation in the Department of Defense's Defense Advanced Research Project relating to technology needed to improve the product development process is described, particularly in the area of advanced weapon systems. The efforts committed to improving collaboration among the diverse and distributed health care providers are reported, along with the research activities for NASA in Independent Software Verification and Validation. CERC also takes part in the electronic respirator certification initiated by The National Institute for Occupational Safety and Health, as well as in the efforts to find a solution to the problem of producing environment-friendly end-products for product developers worldwide. The 3M Fiber Metal Matrix Composite Model Factory Program is discussed. CERC technologies, facilities,and personnel-related issues are described, along with its library and technical services and recent publications.

  2. Modal abstractions of concurrent behavior

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nanz, Sebastian; Nielson, Hanne Riis

    2011-01-01

    We present an effective algorithm for the automatic construction of finite modal transition systems as abstractions of potentially infinite concurrent processes. Modal transition systems are recognized as valuable abstractions for model checking because they allow for the validation as well...... as refutation of safety and liveness properties. However, the algorithmic construction of finite abstractions from potentially infinite concurrent processes is a missing link that prevents their more widespread usage for model checking of concurrent systems. Our algorithm is a worklist algorithm using concepts...

  3. Associations of retrospective and concurrent lipid levels with subclinical atherosclerosis prediction after 20 years of follow-up: the Coronary Artery Risk Development in Young Adults (CARDIA) study

    Science.gov (United States)

    Raynor, Lewis A.; Schreiner, Pamela J.; Loria, Catherine M.; Carr, J. Jeffrey; Pletcher, Mark J.; Shikany, James M.

    2017-01-01

    Purpose Using data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, we sought to determine how well lipids measured at baseline and at 20 years predict the presence of subclinical atherosclerosis. Methods Complete risk factor, coronary artery calcification (CAC), and carotid intima media thickness (CIMT) data were available for 2435 participants. Lipids were categorized into quartiles, CAC at Y20 was dichotomized as present/absent, and CIMT was dichotomized as ≥84 or <84th overall percentile. Multivariable logistic regression was used to model the association between lipids and CAC/CIMT. C statistics were used to assess the discriminative value of each lipid measure in predicting the presence of CAC or CIMT at Y20. Results Lipid levels measured in young adulthood as well as middle age were both associated with subclinical disease in middle age. The discriminatory value of lipids was virtually identical at baseline, when participants were 18–30 years of age, and 20 years later. Neither baseline nor Y20 lipid data were strong predictors of Y20 subclinical disease despite statistically significant associations. Conclusions These results are consistent with a growing body of evidence that early-life exposure to nonoptimal lipids matters and lifestyle modifications administered earlier in the lifespan could slow the progress of the atherosclerotic plaques. PMID:23889858

  4. Extractive Spectrophotometric Method for the Determination of Lamivudine and Zidovudine in Pharmaceutical Preparations Using Bromocresol Purple

    Directory of Open Access Journals (Sweden)

    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available A new spectrophotometric method has been established for the quantitation of lamivudine (LVD and zidovudine (ZVD in pharmaceutical preparations. The method is based on the reaction between the investigated drug substances and bromocresol purple (BCP producing ion-pair complexes in acidic buffers which are suitable for chloroform extraction. The maximum absorbance of these complexes was measured at 424 nm in chloroform. All variables were studied to optimize the reaction conditions. Linearity ranges were found to be 25–250 μg mL−1 for LVD-BCP and 50–300 μg mL−1 for ZVD-BCP. The developed method was successfully applied for the determination of these drugs in pharmaceutical preparations. Excipients in pharmaceutical formulations did not interfere in the analysis. The results were compared statistically with those obtained by the HPLC method reported in the literature. According to the results, the proposed method can be recommended for quality control and routine analysis.

  5. Economic explanations for concurrent sourcing

    DEFF Research Database (Denmark)

    Mols, Niels Peter

    2010-01-01

    Concurrent sourcing is a phenomenon where firms simultaneously make and buy the same good, i.e. they simultaneously use the governance modes of market and hierarchy. Though concurrent sourcing seems to be widespread, few studies of sourcing have focused on this phenomenon. This paper reviews diff...... different economic explanations for why firms use concurrent sourcing. The distinctive features of the explanations are compared, and it is discussed how they may serve as a springboard for research on concurrent sourcing. Managerial implications are also offered....

  6. Efficacy of zidovudine and human immunodeficiency virus (HIV) hyperimmune immunoglobulin for reducing perinatal HIV transmission from HIV-infected women with advanced disease: results of Pediatric AIDS Clinical Trials Group protocol 185.

    Science.gov (United States)

    Stiehm, E R; Lambert, J S; Mofenson, L M; Bethel, J; Whitehouse, J; Nugent, R; Moye, J; Glenn Fowler, M; Mathieson, B J; Reichelderfer, P; Nemo, G J; Korelitz, J; Meyer, W A; Sapan, C V; Jimenez, E; Gandia, J; Scott, G; O'Sullivan, M J; Kovacs, A; Stek, A; Shearer, W T; Hammill, H

    1999-03-01

    Pediatric AIDS Clinical Trials Group protocol 185 evaluated whether zidovudine combined with human immunodeficiency virus (HIV) hyperimmune immunoglobulin (HIVIG) infusions administered monthly during pregnancy and to the neonate at birth would significantly lower perinatal HIV transmission compared with treatment with zidovudine and intravenous immunoglobulin (IVIG) without HIV antibody. Subjects had baseline CD4 cell counts /=200/microL) but not with time of zidovudine initiation (5.6% vs. 4.8% if started before vs. during pregnancy; P=. 75). The Kaplan-Meier transmission rate for HIVIG recipients was 4. 1% (95% confidence interval, 1.5%-6.7%) and for IVIG recipients was 6.0% (2.8%-9.1%) (P=.36). The unexpectedly low transmission confirmed that zidovudine prophylaxis is highly effective, even for women with advanced HIV disease and prior zidovudine therapy, although it limited the study's ability to address whether passive immunization diminishes perinatal transmission.

  7. CRDTs: Consistency without concurrency control

    CERN Document Server

    Letia, Mihai; Shapiro, Marc

    2009-01-01

    A CRDT is a data type whose operations commute when they are concurrent. Replicas of a CRDT eventually converge without any complex concurrency control. As an existence proof, we exhibit a non-trivial CRDT: a shared edit buffer called Treedoc. We outline the design, implementation and performance of Treedoc. We discuss how the CRDT concept can be generalised, and its limitations.

  8. A Lower Bound on Concurrence

    Institute of Scientific and Technical Information of China (English)

    LIU Li-Guo; TIAN Cheng-Lin; CHEN Ping-Xing; YUAN Nai-Chang

    2009-01-01

    We derive an analytical lower bound on the concurrence for bipartite quantum systems with an improved computable cross norm or realignment criterion and an improved positive partial transpose criterion respectively.Furthermore we demonstrate that our bound is better than that obtained from the local uncertainty relations criterion with optimal local orthogonal observables which is known as one of the best estimations of concurrence.

  9. Concurrent Validity and Holland's Theory

    Science.gov (United States)

    Gaffey, Robert L.; Walsh, W. Bruce

    1974-01-01

    This study was designed to explore two areas: (1) the concurrent validity of Holland's theory for employed men using four different operational definitions of vocational orientation, and (2) the relationships among all possible combinations of same named scales across the four inventories. Findings tend to support the concurrent validity of…

  10. Concurrent Validity and Holland's Theory

    Science.gov (United States)

    Gaffey, Robert L.; Walsh, W. Bruce

    1974-01-01

    This study was designed to explore two areas: (1) the concurrent validity of Holland's theory for employed men using four different operational definitions of vocational orientation, and (2) the relationships among all possible combinations of same named scales across the four inventories. Findings tend to support the concurrent validity of…

  11. Very-High Level Concurrent Programming.

    Science.gov (United States)

    1984-12-01

    individual modules at runtime (section 11.8). 3.5 CODE GEERATION In this phase, the Confiurator generates JCL and PVI programs for the execution of a...i’CH42 /1(4)1: /E(2)/ (ILNAMES30 IcPF- / Z (4)/ : /E(2)/ cPNGMESo cARRV~i - /ARROK/ (K): :/REOV (F) :~/RECF/ <NLjkAHS’% : HPIUAME) /ADDNAME/ CKMJAE...described in section 10.3. 0 I Z 2. A pair of nodes v and w in a configuration is said to be DIRECTLY EQUIVALDIT, denoted by v < ) w, if and only if: i

  12. Baseline severe anaemia should not preclude use of zidovudine in antiretroviral-eligible patients in resource-limited settings

    Science.gov (United States)

    2010-01-01

    Background Stavudine is no longer recommended as part of first-line therapy for patients initiating antiretroviral therapy (ART) in Uganda. Most patients are currently initiated on zidovudine-containing regimens, which can induce anaemia. We investigated the risk factors for early severe anaemia in the first six months of ART initiation. Methods We defined baseline (ART initiation) anaemia as haemoglobin (Hb) ≤9.5 g/dL, baseline severe anaemia as Hb ≤8 g/dL, and early severe anaemia as Hb ≤8 g/dL within six months of ART initiation. Risk factors for the development of early severe anaemia were analyzed using a multivariable logistic regression model. Results In total, 5494 patients initiated ART, 821 (15%) had baseline anaemia, and 296 (5%) had baseline severe anaemia. Early severe anaemia occurred in 109 (4%) of 3105 patients who had at least one Hb measurement in the first six months on ART. Patients with baseline anaemia had a larger increase in Hb (median g/dL [IQR]) within the first six months compared with non-anaemic patients (2.9 [1.7, 4.6] vs. 0.7 [-0.2, 1.7], p anaemia OR 5.27 (95% CI 3.00 - 9.26) were associated with early severe anaemia. Initiation on a zidovudine-based regimen was not associated with an increased risk of early severe anaemia. Conclusions Among patients in an urban HIV clinic in Uganda, severe anaemia is modestly prevalent at ART initiation and improves with ART in the majority of patients. These data suggest that baseline severe anaemia should not be used as a criterion for avoiding the use of zidovudine in patients initiating ART in resource-limited settings. PMID:21047391

  13. The NRTIs Lamivudine, Stavudine and Zidovudine Have Reduced HIV-1 Inhibitory Activity in Astrocytes

    Science.gov (United States)

    Gray, Lachlan R.; Tachedjian, Gilda; Ellett, Anne M.; Roche, Michael J.; Cheng, Wan-Jung; Guillemin, Gilles J.; Brew, Bruce J.; Turville, Stuart G.; Wesselingh, Steve L.; Gorry, Paul R.; Churchill, Melissa J.

    2013-01-01

    HIV-1 establishes infection in astrocytes and macroage-lineage cells of the central nervous system (CNS). Certain antiretroviral drugs (ARVs) can penetrate the CNS, and are therefore often used in neurologically active combined antiretroviral therapy (Neuro-cART) regimens, but their relative activity in the different susceptible CNS cell populations is unknown. Here, we determined the HIV-1 inhibitory activity of CNS-penetrating ARVs in astrocytes and macrophage-lineage cells. Primary human fetal astrocytes (PFA) and the SVG human astrocyte cell line were used as in vitro models for astrocyte infection, and monocyte-derived macrophages (MDM) were used as an in vitro model for infection of macrophage-lineage cells. The CNS-penetrating ARVs tested were the nucleoside reverse transcriptase inhibitors (NRTIs) abacavir (ABC), lamivudine (3TC), stavudine (d4T) and zidovudine (ZDV), the non-NRTIs efavirenz (EFV), etravirine (ETR) and nevirapine (NVP), and the integrase inhibitor raltegravir (RAL). Drug inhibition assays were performed using single-round HIV-1 entry assays with luciferase viruses pseudotyped with HIV-1 YU-2 envelope or vesicular stomatitis virus G protein (VSV-G). All the ARVs tested could effectively inhibit HIV-1 infection in macrophages, with EC90s below concentrations known to be achievable in the cerebral spinal fluid (CSF). Most of the ARVs had similar potency in astrocytes, however the NRTIs 3TC, d4T and ZDV had insufficient HIV-1 inhibitory activity in astrocytes, with EC90s 12-, 187- and 110-fold greater than achievable CSF concentrations, respectively. Our data suggest that 3TC, d4T and ZDV may not adequately target astrocyte infection in vivo, which has potential implications for their inclusion in Neuro-cART regimens. PMID:23614033

  14. Is zidovudine first-line therapy virologically comparable to tenofovir in resource-limited settings?

    Science.gov (United States)

    Labhardt, Niklaus D; Bader, Joëlle; Lejone, Thabo Ismael; Ringera, Isaac; Puga, Daniel; Glass, Tracy R; Klimkait, Thomas

    2015-07-01

    To compare virologic success between adult patients on tenofovir (TDF) and zidovudine (AZT)-containing first-line antiretroviral (ART) regimens in 10 rural clinics in Lesotho, Southern Africa. Multicentre cross-sectional study, patients ≥16 years, on first-line ART ≥6 months, receiving AZT/lamivudine (3TC) or TDF/3TC combined with efavirenz (EFV) or nevirapine (NVP). Patient characteristics and clinical/therapeutic history were collected on the day of blood draw for viral load (VL). Analysis was stratified for non-nucleoside reverse transcriptase inhibitor (EFV or NVP). A logistic regression model weighted for patients' baseline characteristics was used to assess the likelihood of virologic success (<80 copies/ml) in patients with TDF- as compared to AZT-backbones. In total 1539 patients were included in the analysis. Most were clinically and immunologically stable (clinical failure: 2.7% (AZT) and 2.8% (TDF); immunological failure: 4.6% (AZT) and 4.8% (TDF)). In EFV-based regimens (n = 1162), TDF was significantly associated with higher rates of virologic suppression than AZT (93.8% vs. 88.1%; weighted odds ratio: 2.15 (95% CI: 1.29-3.58; P = 0.003)). In NVP-based regimens, a similar trend was observed, but not significant (89.4% vs. 86.7%; 1.99 (0.83-4.75, P = 0.121)). These findings support the WHO recommendation to use TDF/3TC/EFV as first-line regimen. They do, however, not support the recommendation that patients who are clinically stable on AZT should continue on this first-line regimen. © 2015 John Wiley & Sons Ltd.

  15. Steady-state pharmacokinetics of zidovudine in Chinese HIV-infected patients

    Institute of Scientific and Technical Information of China (English)

    LIU Li-feng; WANG Lu; FU Qiang; ZHU Zhu; XIE Jing; HAN Yang; LIU Zheng-yin; YE Min; LI Tai-sheng

    2012-01-01

    Background The pharmacokinetics of zidovudine (AZT) are possibly influenced by weight,age,sex,liver and renal functions,severity of disease,and ethnicity.Currently,little information is available on the steady-state pharmacokinetics of AZT in Chinese HIV-infected patients.The current study aimed to characterize the steady-state pharmacokinetics of AZT in a Chinese set-up.Methods Eleven Chinese HIV-infected patients were involved in the steady-state pharmacokinetic study.In total,300 mg of AZT,as a part of combination therapy,was given to patients,and serial blood samples were collected for 12 hours.The samples were measured by a high-performance liquid chromatography (HPLC) assay,and the results were analyzed by both the non-compartment model and the one-compartment model.Results The Cmax of AZT in Chinese patients was higher than that in non-Asian patients.The half-life of AZT,analyzed by the non-compartment model (P=0.02),in male patients ((1.02±0.22) hours) was shorter than that of AZT in female patients ((1.55±0.29) hours).The AZT clearance,analyzed by the one-compartment model (P=0.045),in male patients ((262.60±28.13) L/h) was higher than that in female patients ((195.85±60.51 ) L/h).Conclusion The present study provides valuable information for the clinical practice of AZT-based highly active antiretroviral therapy in a Chinese set-up.

  16. The NRTIs lamivudine, stavudine and zidovudine have reduced HIV-1 inhibitory activity in astrocytes.

    Directory of Open Access Journals (Sweden)

    Lachlan R Gray

    Full Text Available HIV-1 establishes infection in astrocytes and macroage-lineage cells of the central nervous system (CNS. Certain antiretroviral drugs (ARVs can penetrate the CNS, and are therefore often used in neurologically active combined antiretroviral therapy (Neuro-cART regimens, but their relative activity in the different susceptible CNS cell populations is unknown. Here, we determined the HIV-1 inhibitory activity of CNS-penetrating ARVs in astrocytes and macrophage-lineage cells. Primary human fetal astrocytes (PFA and the SVG human astrocyte cell line were used as in vitro models for astrocyte infection, and monocyte-derived macrophages (MDM were used as an in vitro model for infection of macrophage-lineage cells. The CNS-penetrating ARVs tested were the nucleoside reverse transcriptase inhibitors (NRTIs abacavir (ABC, lamivudine (3TC, stavudine (d4T and zidovudine (ZDV, the non-NRTIs efavirenz (EFV, etravirine (ETR and nevirapine (NVP, and the integrase inhibitor raltegravir (RAL. Drug inhibition assays were performed using single-round HIV-1 entry assays with luciferase viruses pseudotyped with HIV-1 YU-2 envelope or vesicular stomatitis virus G protein (VSV-G. All the ARVs tested could effectively inhibit HIV-1 infection in macrophages, with EC90s below concentrations known to be achievable in the cerebral spinal fluid (CSF. Most of the ARVs had similar potency in astrocytes, however the NRTIs 3TC, d4T and ZDV had insufficient HIV-1 inhibitory activity in astrocytes, with EC90s 12-, 187- and 110-fold greater than achievable CSF concentrations, respectively. Our data suggest that 3TC, d4T and ZDV may not adequately target astrocyte infection in vivo, which has potential implications for their inclusion in Neuro-cART regimens.

  17. Improved Safety, Bioavailability and Pharmacokinetics of Zidovudine through Lactoferrin Nanoparticles during Oral Administration in Rats.

    Directory of Open Access Journals (Sweden)

    Prashant Kumar

    Full Text Available Zidovudine (AZT is one of the most referred antiretroviral drug. In spite of its higher bioavailability (50-75% the most important reason of its cessation are bone marrow suppression, anemia, neutropenia and various organs related toxicities. This study aims at the improvement of oral delivery of AZT through its encapsulation in lactoferrin nanoparticles (AZT-lactonano. The nanoparticles (NPs are of 50-60 nm in size and exhibit 67% encapsulation of the AZT. They are stable in simulated gastric and intestinal fluids. Anti-HIV-1 activity of AZT remains unaltered in nanoformulation in acute infection. The bioavailability and tissue distribution of AZT is higher in blood followed by liver and kidney. AZT-lactonano causes the improvement of pharmacokinetic profile as compared to soluble AZT; a more than 4 fold increase in AUC and AUMC in male and female rats. The serum Cmax for AZT-lactonano was increased by 30%. Similarly there was nearly 2-fold increase in Tmax and t1/2. Our in vitro study confirms that, the endosomal pH is ideal for drug release from NPs and shows constant release from up to 96h. Bone marrow micronucleus assay show that nanoformulation exhibits approximately 2fold lower toxicity than soluble form. Histopathological and biochemical analysis further confirms that less or no significant organ toxicities when nanoparticles were used. AZT-lactonano has shown its higher efficacy, low organs related toxicities, improved pharmacokinetics parameter while keeping the antiviral activity intact. Thus, the nanoformulation are safe for the target specific drug delivery.

  18. Validação de limpeza de zidovudina: estratégia aplicada ao processo de fabricação de medicamentos anti-retrovirais Cleaning validation of zidovudine: strategy applied to the process manufacture of antiretroviral medicines

    Directory of Open Access Journals (Sweden)

    João Rui Barbosa de Alencar

    2004-03-01

    Full Text Available A validação de limpeza é parte integrante do conjunto de normas que compõem as boas práticas de fabricação de medicamentos. Trata-se de sistemática utilizada para assegurar que os procedimentos de limpeza de equipamentos, efetivamente, removam os resíduos existentes até um nível de aceitação pré-determinado. Poucos trabalhos abordando a validação de limpeza estão disponíveis na literatura concernente à área. Neste, apresenta-se estratégia para validação do processo de limpeza utilizado na fabricação do medicamento zidovudina, produzido pelo LAFEPE® (Recife - PE, Brasil largamente prescrito no tratamento da AIDS. Utilizou-se um método analítico por via espectrofotométrica e técnica de amostragem de superfícies por swab. O critério de aceitação da limpeza utilizado foi de 10 ppm de zidovudina no produto subseqüente (estavudina. Os resíduos de zidovudina encontrados nos equipamentos após a limpeza foram inferiores aos critérios de aceitação da limpeza, bem como do menor nível de concentração capaz de provocar ação farmacológica.The cleaning validation is integrant part of the laws of good manufacturing practices of medicines. Cleaning validation procedures are carried out in order to assure that residues are within acceptable limits after the cleaning process. Very little has been published regarding practices within the pharmaceutical industry. This work presents a strategy for cleaning validation of the process equipments of the medicine zidovudine produced by LAFEPE (Recife - PE, Brazil utilized in AIDS treatment. An analytical method by spectrofotometry and samples surfaces by swab was utilized. The acceptance criteria from the cleaning utilized was 10 ppm of zidovudine in the subsequent product (stavudine. The residues of zidovudine found in the equipment after cleaning were lower that limits established as well as to the smaller level of concentration capable of producing pharmacological effects.

  19. A CAD MODEL FOR FUZZY CONCURRENT TOLERANCE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Research situation of concurrent tolerance design has been analyzed. As fuzzy factors are objective and unavoidable in concurrent tolerance design, fuzzy optimization theory is applied in the design. A new mathematical model of concurrent tolerance design is constructed.

  20. Time concurrency/phase-time synchronization in digital communications networks

    Science.gov (United States)

    Kihara, Masami; Imaoka, Atsushi

    1990-01-01

    Digital communications networks have the intrinsic capability of time synchronization which makes it possible for networks to supply time signals to some applications and services. A practical estimation method for the time concurrency on terrestrial networks is presented. By using this method, time concurrency capability of the Nippon Telegraph and Telephone Corporation (NTT) digital communications network is estimated to be better than 300 ns rms at an advanced level, and 20 ns rms at final level.

  1. Reference Capabilities for Concurrency Control

    OpenAIRE

    Castegren, Elias; Wrigstad, Tobias

    2016-01-01

    The proliferation of shared mutable state in object-oriented programming complicates software development as two seemingly unrelated operations may interact via an alias and produce unexpected results. In concurrent programming this manifests itself as data-races. Concurrent object-oriented programming further suffers from the fact that code that warrants synchronisation cannot easily be distinguished from code that does not. The burden is placed solely on the programmer to reason ab...

  2. Zidovudine plus lamivudine in Human T-Lymphotropic Virus type-I-associated myelopathy: a randomised trial

    Directory of Open Access Journals (Sweden)

    Rudge Peter

    2006-09-01

    Full Text Available Abstract Background No therapies have been proven to persistently improve the outcome of HTLV-I-associated myelopathy. Clinical benefit has been reported with zidovudine and with lamivudine in observational studies. We therefore conducted a randomised, double blind, placebo controlled study of six months combination therapy with these nucleoside analogues in sixteen patients. Results Primary outcomes were change in HTLV-I proviral load in PBMCs and clinical measures. Secondary endpoints were changes in T-cell subsets and markers of activation and proliferation. Six patients discontinued zidovudine. No significant changes in pain, bladder function, disability score, gait, proviral load or markers of T-cell activation or proliferation were seen between the two arms. Active therapy was associated with an unexplained decrease in CD8 and non-T lymphocyte counts. Conclusion Failure to detect clinical improvement may have been due irreversible nerve damage in these patients with a long clinical history and future studies should target patients presenting earlier. The lack of virological effect but may reflect a lack of activity of these nucleoside analogues against HTLV-I RT in vivo, inadequate intracellular concentrations of the active moiety or the contribution of new cell infection to maintaining proviral load at this stage of infection may be relatively small masking the effects of RT inhibition.

  3. Concurrent engineering: effective deployment strategies

    Directory of Open Access Journals (Sweden)

    Unny Menon

    1996-12-01

    Full Text Available This paper provides a comprehensive insight into current trends and developments in Concurrent Engineering for integrated development of products and processes with the goal of completing the entire cycle in a shorter time, at lower overall cost and with fewer engineering design changes after product release. The evolution and definition of Concurrent Engineering are addressed first, followed by a concise review of the following elements of the concurrent engineering approach to product development: Concept Development: The Front-End Process, identifying Customer Needs and Quality Function Deployment, Establishing Product Specifications, Concept Selection, Product Architecture, Design for Manufacturing, Effective Rapid Prototyping, and The Economics of Product Development. An outline of a computer-based tutorial developed by the authors and other graduate students funded by NASA ( accessible via the world-wide-web . is provided in this paper. A brief discussion of teamwork for successful concurrent engineering is included, t'ase histories of concurrent engineering implementation at North American and European companies are outlined with references to textbooks authored by Professor Menon and other writers. A comprehensive bibliography on concurrent engineering is included in the paper.

  4. Location pairs: a test coverage metric for shared-memory concurrent programs

    OpenAIRE

    Keremoğlu, M. Erkan; Taşıran, Serdar; Muslu, Kıvanç

    2012-01-01

    We present a coverage metric targeted at shared-memory concurrent programs: the Location Pairs (LP) coverage metric. The goals of this metric are (i) to measure how thoroughly a program has been tested from a concurrency standpoint, i.e., whether enough qualitatively different thread interleavings have been explored, and (ii) to guide testing towards unexplored concurrency scenarios. This metric was inspired by an access pattern known to lead to high-level concurrency errors in industrial sof...

  5. Cost-effectiveness of tenofovir instead of zidovudine for use in first-line antiretroviral therapy in settings without virological monitoring

    DEFF Research Database (Denmark)

    von Wyl, Viktor; Cambiano, Valentina; Jordan, Michael R

    2012-01-01

    The most recent World Health Organization (WHO) antiretroviral treatment guidelines recommend the inclusion of zidovudine (ZDV) or tenofovir (TDF) in first-line therapy. We conducted a cost-effectiveness analysis with emphasis on emerging patterns of drug resistance upon treatment failure and the...

  6. Zidovudine and isoniazid induced liver toxicity and oxidative stress: Evaluation of mitigating properties of silibinin.

    Science.gov (United States)

    Raghu, Ramanathan; Karthikeyan, Sivanesan

    2016-09-01

    HIV/AIDS patients are more prone for opportunistic TB infections and they are administered the combined regimen of anti-retroviral drug zidovudine (AZT) and isoniazid (INH) for therapy. However, AZT+INH treatment has been documented to induce injury and remedial measures to prevent this adversity are not clearly defined. Silibinin (SBN) is a natural hepatoprotective principle isolated from medicinal plant Silybum marianum and is currently used for therapy of various liver diseases. This study investigate the hepatotoxic potentials of AZT alone, INH alone and AZT+INH treatments and the mitigating potentials of SBN against these drugs induced toxic insults of liver in rats. Separate groups of rats (n=6 in each group) were administered AZT alone (50mg/kg b.w.), INH alone (25mg/kg, b.w.), AZT+INH (50mg/kg, b.w. and 25mg/kg, b.w.), SBN alone (100mg/kg, b.w.) and SBN+AZT+INH daily for sub-chronic period of 45days orally. The control rats received saline/propylene glycol. INH alone and AZT+INH-induced parenchymal cell injury and cholestasis of liver was evidenced by highly significant increase in the activities of marker enzymes (aspartate and alanine transaminase, alkaline phosphatase, argino succinic acid lyase), bilirubin, protein, oxidative stress parameters (lipid peroxidation, superoxide dismutase, catalase, reduced glutathione, vitamins C and E) and membrane bound ATPases were evaluated in serum/liver tissue homogenates. Histopathological studies show ballooning degradation, inflammatory lesions, lipid deposition and hydropic changes in the liver tissue. All the above biochemical and pathological changes induced by AZT+INH treatments were mitigated in rats receiving SBN simultaneously with these hepatotoxins, indicating its hepatoprotective and antioxidant potentials against AZT+INH-induced hepatotoxicity. The moderate hepatoprotective and oxidant potentials of SBN could be due to its low bioavailability and this deficiency could be prevented by supplementation of

  7. Managing Complexity of Control Software through Concurrency

    NARCIS (Netherlands)

    Hilderink, G.H.

    2005-01-01

    In this thesis, we are concerned with the development of concurrent software for embedded systems. The emphasis is on the development of control software. Embedded systems are concurrent systems whereby hardware and software communicate with the concurrent world. Concurrency is essential, which

  8. Concurrent Engineering Research and Application

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Research and application of Concurrent Engineering have produced good results. A Chinese style concurrent engineering architecture and reference mode has been produced. A series of break thoughts in BPR (Business Process Reengineering) have been made with organization of the IPT (Integrated Product Development Team) and engineering support technologies. Several prototype tools were developed, including product development process modeling and management, QFD-based schema design and decision making, PDM-based concurrent design, STEP-based CAD/CAPP/CAM integration, design for assembly, design for manufacturing, computer aided fixture design, and machining process simulation. Finally, the research results were used in the development of two complex components in an aerospace application, and satisfactory results were obtained.

  9. STU attractors from vanishing concurrence

    CERN Document Server

    Lévay, Péter

    2010-01-01

    Concurrence is an entanglement measure characterizing the {\\it mixed} state bipartite correlations inside of a pure state of an $n$-qubit system. We show that after organizing the charges and the moduli in the STU model of $N=2$, $d=4$ supergravity to a three-qubit state, for static extremal spherically symmetric BPS black hole solutions the vanishing condition for all of the bipartite concurrences on the horizon is equivalent to the attractor equations. As a result of this the macroscopic black hole entropy given by the three-tangle can be reinterpreted as a linear entropy characterizing the {\\it pure} state entanglement for an arbitrary bipartite split. Both for the BPS and non-BPS cases explicit expressions for the concurrences are obtained, with their vanishing on the horizon is demonstrated.

  10. Poly(ethylene oxide/propylene oxide) copolymer thermo-reversible gelling system for the enhancement of intranasal zidovudine delivery to the brain.

    Science.gov (United States)

    Ved, Parag M; Kim, Kwonho

    2011-06-15

    The purpose of this study was to investigate the olfactory transfer of zidovudine (ZDV) after intranasal (IN) administration and to assess the effect of thermoreversible gelling system on its absorption and brain uptake. The nasal formulation was prepared by dissolving ZDV in pH 5.5 phosphate buffer solution comprising of 20% polyethylene oxide/propylene oxide (Poloxamer 407, PLX) as thermoreversible gelling agent and 0.1% n-tridecyl-β-D-maltoside (TDM) as permeation enhancer. This formulation exhibited a sufficient stability and an optimum gelation profile at 27-30 °C. The in vitro permeation studies across the freshly excised rabbit nasal mucosa showed a 53% increase in the permeability of ZDV from the formulation. For in vivo evaluation, the drug concentrations in the plasma, cerebrospinal fluid (CSF) and six different regions of the brain tissues, i.e. olfactory bulb (OB), olfactory tract (OT), anterior, middle and posterior segments of cerebrum (CB), and cerebellum (CL) were determined by LC/MS method following IV and IN administration in rabbits at a dose of 1mg/kg. The IN administration of Poloxamer 407 and TDM based formulation showed a systemic bioavailability of 29.4% while exhibiting a 4 times slower absorption process (t(max) = 20 min) than control solution (t(max) = 5 min). The CSF and brain ZDV levels achieved after IN administration of the gelling formulation were approximately 4.7-56 times greater than those attained after IV injection. The pharmacokinetic and brain distribution studies revealed that a polar antiviral compound, ZDV could preferentially transfer into the CSF and brain tissue via an alternative pathway, possibly olfactory route after intranasal administration.

  11. Fuzzy simulation in concurrent engineering

    Science.gov (United States)

    Kraslawski, A.; Nystrom, L.

    1992-01-01

    Concurrent engineering is becoming a very important practice in manufacturing. A problem in concurrent engineering is the uncertainty associated with the values of the input variables and operating conditions. The problem discussed in this paper concerns the simulation of processes where the raw materials and the operational parameters possess fuzzy characteristics. The processing of fuzzy input information is performed by the vertex method and the commercial simulation packages POLYMATH and GEMS. The examples are presented to illustrate the usefulness of the method in the simulation of chemical engineering processes.

  12. Concurrency & Asynchrony in Declarative Workflows

    DEFF Research Database (Denmark)

    Debois, Søren; Hildebrandt, Thomas; Slaats, Tijs

    2015-01-01

    Declarative or constraint-based business process and workflow notations have received increasing interest in the last decade as possible means of addressing the challenge of supporting at the same time flexibility in execution, adaptability and compliance. However, the definition of concurrent...... of concurrency in DCR Graphs admits asynchronous execution of declarative workflows both conceptually and by reporting on a prototype implementation of a distributed declarative workflow engine. Both the theoretical development and the implementation is supported by an extended example; moreover, the theoretical...

  13. Fuzzy simulation in concurrent engineering

    Science.gov (United States)

    Kraslawski, A.; Nystrom, L.

    1992-01-01

    Concurrent engineering is becoming a very important practice in manufacturing. A problem in concurrent engineering is the uncertainty associated with the values of the input variables and operating conditions. The problem discussed in this paper concerns the simulation of processes where the raw materials and the operational parameters possess fuzzy characteristics. The processing of fuzzy input information is performed by the vertex method and the commercial simulation packages POLYMATH and GEMS. The examples are presented to illustrate the usefulness of the method in the simulation of chemical engineering processes.

  14. [Prevalence of transmission of zidovudine-resistant viruses in Switzerland. l'Etude suisse de cohorte VIH].

    Science.gov (United States)

    Yerly, S; Rakik, A; Kinloch-de-Loes, S; Erb, P; Vernazza, P; Hirschel, B; Perrin, L

    1996-10-26

    Zidovudine (ZDV) was the most widely used anti-HIV drug between 1987 and 1995, and, as already reported, transmission of ZDV-resistant viruses occurs. Several mutations of the reverse transcriptase gene have been identified; one of them affects the 215 codon and is associated with a high degree of resistance. We have determined, using selective PCR, the prevalence of transmission of 215 mutant isolates in 134 patients with primary HIV infection (PHI) and have identified 8 patients with 215 mutant virus between 1989 and 1995 in Switzerland. Mutant resistant viruses have been isolated from patients treated with most antiviral drugs. A systematic search for mutant viruses may provide useful information for the adaptation of treatment strategies.

  15. Superior Effectiveness of Zidovudine Compared With Tenofovir When Combined With Nevirapine-based Antiretroviral Therapy in a Large Nigerian Cohort

    Science.gov (United States)

    Scarsi, Kimberly K.; Eisen, Geoffrey; Darin, Kristin M.; Meloni, Seema T.; Rawizza, Holly E.; Tchetgen Tchetgen, Eric J.; Agbaji, Oche O.; Onwujekwe, Daniel I.; Gashau, Wadzani; Nkado, Reuben; Okonkwo, Prosper; Murphy, Robert L.; Kanki, Phyllis J.

    2016-01-01

    Background. Despite sparse efficacy data, tenofovir–emtricitabine or tenofovir–lamivudine plus nevirapine is used in many resource-constrained settings. Methods. This retrospective cohort study included patients initiating nevirapine-based antiretroviral therapy (ART) with either tenofovir–emtricitabine or lamivudine (tenofovir group) or zidovudine–lamivudine (zidovudine group). Clinical, virologic, and immunologic evaluations were performed at baseline and every 6 months. Virologic failure was defined as 2 consecutive human immunodeficiency virus (HIV)-RNA values >1000 copies/mL. Patients were included from ART initiation until time of failure, regimen switch, discontinuation, or last HIV-RNA measurement. Cox proportional hazards regression was used to model factors influencing time to failure. Bias due to dependent censoring was investigated via inverse probability weighted pooled logistic regression. Results. A total of 5547 patients were evaluated; 1484 (26.8%) were in the tenofovir group and 4063 (73.2%) were in the zidovudine group. In the adjusted model, tenofovir regimen (hazard ratio [HR], 1.47; 95% confidence interval [CI], 1.21–1.79) and higher baseline log10 HIV-RNA (HR, 1.15; 95% CI, 1.03–1.28) were associated with virologic failure. Higher baseline log10 CD4+ cell count (HR, 0.50; 95% CI, .40–.63) and increasing age (HR, 0.98; 95% CI, .97–.99) decreased the risk of virologic failure. Inverse probability weighting results were consistent with the primary analysis. Conclusions. Compared with zidovudine–lamivudine, the use of tenofovir–lamivudine or emtricitabine in combination with nevirapine was a strong predictor of virologic failure in our cohort, which was not explained by other risk factors or criteria for regimen selection. PMID:26561532

  16. Session-based concurrency, reactively

    NARCIS (Netherlands)

    M. Cano (Mauricio); J. Arias (Jaime); J.A. Pérez Parra (Jorge)

    2017-01-01

    textabstractThis paper concerns formal models for the analysis of communication-centric software systems that feature declarative and reactive behaviors. We focus on session-based concurrency, the interaction model induced by session types, which uses (variants of) the Π-calculus as specification

  17. Teaching Concurrency: Theory in Practice

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand

    2009-01-01

    in mathematics. We report here on our experiences in teaching concurrency theory over the last twenty years or so to students ranging from mathsphobic bachelor students to sophisticated doctoral students. The contents of the courses, the material on which they are based and the pedagogical philosophy underlying...

  18. Concurrency & Asynchrony in Declarative Workflows

    DEFF Research Database (Denmark)

    Debois, Søren; Hildebrandt, Thomas; Slaats, Tijs

    2015-01-01

    Declarative or constraint-based business process and workflow notations have received increasing interest in the last decade as possible means of addressing the challenge of supporting at the same time flexibility in execution, adaptability and compliance. However, the definition of concurrent se...... development has been verified correct in the Isabelle-HOL interactive theorem prover....

  19. Bisimulation for models in concurrency

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Clausen, Christian

    1994-01-01

    Recently, Joyal, Nielsen and Winskel suggested a categorical definition of bisimulation, applicable to a wide range of models in concurrency with an accompanying notion af observations. The definition is in terms of span of open maps, and it coincides with Park and Milner's strong bisimulation...

  20. The system of concurrent engineering

    NARCIS (Netherlands)

    Wognum, Nel; Trienekens, Jacques

    2015-01-01

    Concurrent engineering (CE) has been a major theme in the 80s and 90s of the previous century in research and practice. Its main aim is to reduce time-tomarket, improve quality and reduce costs by taking into account downstream requirements and constraints already in the design phase. While start

  1. Visualization of Concurrent Program Executions

    Science.gov (United States)

    Artho, Cyrille; Havelund, Klaus; Honiden, Shinichi

    2007-01-01

    Various program analysis techniques are efficient at discovering failures and properties. However, it is often difficult to evaluate results, such as program traces. This calls for abstraction and visualization tools. We propose an approach based on UML sequence diagrams, addressing shortcomings of such diagrams for concurrency. The resulting visualization is expressive and provides all the necessary information at a glance.

  2. Concurrency & Asynchrony in Declarative Workflows

    DEFF Research Database (Denmark)

    Debois, Søren; Hildebrandt, Thomas; Slaats, Tijs

    2015-01-01

    Declarative or constraint-based business process and workflow notations have received increasing interest in the last decade as possible means of addressing the challenge of supporting at the same time flexibility in execution, adaptability and compliance. However, the definition of concurrent se...... development has been verified correct in the Isabelle-HOL interactive theorem prover....

  3. True Concurrency can be Traced

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik

    1990-01-01

    In this paper sets of labelled partial orders are employed as fundamental mathematical entities for modelling nondeterministic and concurrent processes thereby obtaining so-called noninterleaving semantics. Based on closures of sets of labelled partial orders, a simple algebraic language with ref...

  4. The composition of concurrent programs

    Science.gov (United States)

    Chandy, K. Mani; Taylor, Stephen

    1989-01-01

    A notation is presented for concurrent programs called program composition notation (PCN). The notation is being implemented at Caltech on multicomputers (a network of computers that communicate by sending and receiving messages). A fragment of this notation has been implemented on a data-parallel computer, the Connection Machine. The central ideas underlying PCN are discussed.

  5. Modal abstractions of concurrent behavior

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nanz, Sebastian; Nielson, Hanne Riis

    2011-01-01

    We present an effective algorithm for the automatic construction of finite modal transition systems as abstractions of potentially infinite concurrent processes. Modal transition systems are recognized as valuable abstractions for model checking because they allow for the validation as well as re...

  6. A Model for Concurrent Objects

    DEFF Research Database (Denmark)

    Sørensen, Morten U.

    1996-01-01

    We present a model for concurrent objects where obejcts interact by taking part in common events that are closely matched to form call-response pairs, resulting in resulting in rendez-vous like communications. Objects are built from primitive objects by parallel composition, encapsulation and hid...

  7. True Concurrency can be Traced

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik

    1990-01-01

    In this paper sets of labelled partial orders are employed as fundamental mathematical entities for modelling nondeterministic and concurrent processes thereby obtaining so-called noninterleaving semantics. Based on closures of sets of labelled partial orders, a simple algebraic language with ref...

  8. Verification of Concurrent Assembly Programs with a Petri Net Based Safety Policy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Concurrent programs written in a machine level language are being used in many areas but verification of such programs brings new challenges to the programming language community. Most of the studies in the literature on verifying the safety properties of concurrent programs are for high-level languages,specifications, or calculi. Therefore, more studies are needed on concurrency verification for machine level language programs. This paper describes a framework of a Petri net based safety policy for the verification of concurrent assembly programs, to exploit the capability of Petri nets in concurrency modeling. The concurrency safety properties can be considered separately using the net structure and by mixing Hoare logic and computational tree logic. Therefore, more useful higher-level safety properties can be specified and verified.

  9. Virtual Machine Support for Many-Core Architectures: Decoupling Abstract from Concrete Concurrency Models

    Directory of Open Access Journals (Sweden)

    Stefan Marr

    2010-02-01

    Full Text Available The upcoming many-core architectures require software developers to exploit concurrency to utilize available computational power. Today's high-level language virtual machines (VMs, which are a cornerstone of software development, do not provide sufficient abstraction for concurrency concepts. We analyze concrete and abstract concurrency models and identify the challenges they impose for VMs. To provide sufficient concurrency support in VMs, we propose to integrate concurrency operations into VM instruction sets. Since there will always be VMs optimized for special purposes, our goal is to develop a methodology to design instruction sets with concurrency support. Therefore, we also propose a list of trade-offs that have to be investigated to advise the design of such instruction sets. As a first experiment, we implemented one instruction set extension for shared memory and one for non-shared memory concurrency. From our experimental results, we derived a list of requirements for a full-grown experimental environment for further research.

  10. HIV/AIDS treatment and physicochemical quality control of medicines: evaluation of non-generic lamivudine + zidovudine tablets manufactured in Brazil

    Directory of Open Access Journals (Sweden)

    Ruy Carlos Ruver Beck

    Full Text Available In this work it was evaluated the physicochemical quality of lamivudine + zidovudine tablets, whose association belongs to the list of drugs distributed by the Brazil's National Program on Sexually Transmitted Diseases and AIDS. Four non-generic products (lamivudine + zidovudine tablets were analyzed. They were obtained from different Brazilian manufacturers, besides a reference product. The quality was evaluated by physicochemical tests described in the official codes. A validated reversed-phase high performance liquid chromatography (HPLC method was used for the assay of the active substances. All samples were in accordance to the requisites in relation to their physicochemical characteristics. Dissolution studies showed similar drug percentual dissolved among all samples. The results reflect the interest of the national pharmaceutical industry to ensure the delivery of safer and cheaper drugs to the Brazilian people, with particular importance in the National Program on Sexually Transmitted Diseases and AIDS.

  11. HIV/AIDS treatment and physicochemical quality control of medicines: evaluation of non-generic lamivudine + zidovudine tablets manufactured in Brazil.

    Science.gov (United States)

    Beck, Ruy Carlos Ruver; Athayde, Margareth Linde; Cardoso, Simone Gonçalves

    2007-12-01

    In this work it was evaluated the physicochemical quality of lamivudine + zidovudine tablets, whose association belongs to the list of drugs distributed by the Brazil's National Program on Sexually Transmitted Diseases and AIDS. Four non-generic products (lamivudine + zidovudine tablets) were analyzed. They were obtained from different Brazilian manufacturers, besides a reference product. The quality was evaluated by physicochemical tests described in the official codes. A validated reversed-phase high performance liquid chromatography (HPLC) method was used for the assay of the active substances. All samples were in accordance to the requisites in relation to their physicochemical characteristics. Dissolution studies showed similar drug percentual dissolved among all samples. The results reflect the interest of the national pharmaceutical industry to ensure the delivery of safer and cheaper drugs to the Brazilian people, with particular importance in the National Program on Sexually Transmitted Diseases and AIDS.

  12. PyCSP - controlled concurrency

    DEFF Research Database (Denmark)

    Vinter, Brian; Friborg, Rune Møllegaard; Bjørndalen, John Markus

    2010-01-01

    Producing readable and correct programs while at the same time taking advantage of multi-core architectures is a challenge. PyCSP is an implementation of Communicating Sequential Processes algebra (CSP) for the Python programming language, that take advantage of CSP's formal and verifiable approach...... to controlling concurrency and the readability of Python source code. We describe PyCSP, demonstrate it through examples and demonstrate how PyCSP compares to Pthreads in a master-worker benchmark....

  13. PyCSP - controlled concurrency

    DEFF Research Database (Denmark)

    Friborg, Rune Møllegaard; Vinter, Brian; Bjørndalen, John Markus

    Producing readable and correct programs while at the same time taking advantage of multi-core architectures is a challenge. PyCSP is an implementation of Communicating Sequential Processes algebra (CSP) for the Python programming language, taking advantage of CSP’s formal and verifiable approach...... to controlling concurrency and the readability of Python source code. We describe PyCSP, demonstrate it through examples and demonstrate how PyCSP compares to Pthreads using a benchmark....

  14. Estudio de bioequivalencia: formulaciones genéricas y comerciales de estaduvine, lamiduvine, zidovudine e indinavir en pacientes cubanos infectados con VIH Bioequivalence study: generic and trade formulations of stavudine, lamivudine, zidovudine and indinavir in Cuban HIV-infected subjects

    Directory of Open Access Journals (Sweden)

    Alicia Tarinas Reyes

    2006-08-01

    Full Text Available Objetivo: El presente estudio describe los estudios de bioequivalencia de los genéricos cubanos antirretrovirales estavudina, lamivudina, zidovudina e indinavir con respecto a sus productos innovadores. Diseño: Los estudios de bioequivalencia de cada antirretroviral estudiado (formulación de prueba, P y referencia, R, se realizaron en 13 ó 14 sujetos, según el caso con la utilización de las medias en un estudio aleatorio, cruzado y a dosis única con un período de lavado de 10 días. Métodos: Las concentración de los antirretrovirales en plasma se monitorearon durante un período de 12 h después de la administración de estos, mediante el uso de métodos validados de cromatografía líquida de alta resolución (HPLC. Los parámetros farmacocinéticos se determinaron con el uso el software profesional WinNolin, versión 2.1. La comparación de los parámetros farmacocinéticos se realizó con un intervalo de confianza del 95 % con la utilización del software NCSS 2000 PASS 2000 (hipótesis nula. Para el estudio de bioequivalencia se usó el software Equiv Test de soluciones estadísticas, empleando ANOVA con el 90 % de intervalo de confianza. Resultados: El presente estudio mostró que no se observaron diferencias significativas en las medias de AUC0-12, AUC0-¥, Cmax y Tmax de ambas formulaciones de estavudina, lamivudina, zidovudina e indinavir. Se concluye que los parámetros farmacocinéticos estudiados se encuentran dentro de los rangos establecidos siendo 80-125 % para Cmax, AUC0-12, y AUC0-¥. En el caso de Cmax de la zidovudina el rango fue 70-143 %. Conclusión: Estos resultados avalan que los genéricos antirretrovirales cubanos son bioequivalentes con sus respectivos productos innovadores en términos de velocidad y magnitud de la absorciónObjective: The present study describes the determination of the bioequivalence of the Cuban generic and trade formulations of stavudine, lamivudine, zidovudine, and indinavir. Design: The

  15. Debugging Concurrent Software:Advances and Challenges

    Institute of Scientific and Technical Information of China (English)

    Jeff Huang; Charles Zhang

    2016-01-01

    Concurrency debugging is an extremely important yet challenging problem that has been hampering developer productivity and software reliability in the multicore era. We have worked on this problem in the past eight years and have developed several effective methods and automated tools for helping developers debugging shared memory concurrent programs. This article discusses challenges in concurrency debugging and summarizes our research contributions in four important directions: concurrency bug reproduction, detection, understanding, and fixing. It also discusses other recent advances in tackling these challenges.

  16. Concurrent chemoradiation for vaginal cancer.

    Directory of Open Access Journals (Sweden)

    David T Miyamoto

    Full Text Available BACKGROUND: It is not known whether the addition of chemotherapy to radiation therapy improves outcomes in primary vaginal cancer. Here, we review clinical outcomes in patients with primary vaginal cancer treated with radiation therapy (RT or concurrent chemoradiation therapy (CRT. METHODS: Seventy-one patients with primary vaginal cancer treated with definitive RT with or without concurrent chemotherapy at a single institution were identified and their records reviewed. A total of 51 patients were treated with RT alone; 20 patients were treated with CRT. Recurrences were analyzed. Overall survival (OS and disease-free survival (DFS rates were estimated using the Kaplan-Meier method. Cox regression analysis was performed. RESULTS: The median age at diagnosis was 61 years (range, 18-92 years and the median follow-up time among survivors was 3.0 years. Kaplan-Meier estimates for OS and DFS differed significantly between the RT and CRT groups (3-yr OS = 56% vs. 79%, log-rank p = 0.037; 3-yr DFS = 43% vs. 73%, log-rank p = 0.011. Twenty-three patients (45% in the RT group had a relapse at any site compared to 3 (15% in the CRT group (p = 0.027. With regard to the sites of first relapse, 10 patients (14% had local only, 4 (6% had local and regional, 9 (13% had regional only, 1 (1% had regional and distant, and 2 (3% had distant only relapse. On univariate analysis, the use of concurrent chemotherapy, FIGO stage, tumor size, and date of diagnosis were significant predictors of DFS. On multivariate analysis, the use of concurrent chemotherapy remained a significant predictor of DFS (hazard ratio 0.31 (95% CI, 0.10-0.97; p = 0.04. CONCLUSIONS: Vaginal cancer results in poor outcomes. Adequate radiation dose is essential to ensure curative management. Concurrent chemotherapy should be considered for vaginal cancer patients.

  17. Simple concurrent garbage collection almost without synchronization

    NARCIS (Netherlands)

    Hesselink, Wim H.; Lali, M.I.

    2010-01-01

    We present two simple mark and sweep algorithms, A and B, for concurrent garbage collection by a single collector running concurrently with a number of mutators that concurrently modify shared data. Both algorithms are based on the ideas of Ben-Ari's classical algorithm for on-the-fly garbage collec

  18. Simple concurrent garbage collection almost without synchronization

    NARCIS (Netherlands)

    Hesselink, Wim H.; Lali, M.I.

    We present two simple mark and sweep algorithms, A and B, for concurrent garbage collection by a single collector running concurrently with a number of mutators that concurrently modify shared data. Both algorithms are based on the ideas of Ben-Ari's classical algorithm for on-the-fly garbage

  19. Concurrent fractional and equilibrium crystallisation

    Science.gov (United States)

    Sha, Lian-Kun

    2012-06-01

    This paper proposes the concept of concurrent fractional and equilibrium crystallisation (CFEC) in a multi-phase magmatic system in light of experimental results on diffusivities of elements and other species in minerals and melts. A group of equations are presented to describe how the concentrations of an element or isotope change in fractionated solid, equilibrated solid, melt, liquid, and gas phases, as well as in magma, as a function of distribution coefficients and mass fractions during the CFEC process. CFEC model is a generalised and unified formulation that is valid, not only for pure fractional crystallisation (FC) and perfect equilibrium crystallisation (EC) singly, as two of its limiting end-member cases, but also for the geologically more important process of concurrent fractional and equilibrium crystallisation. The concept that both fractional and equilibrium crystallisation can operate concurrently in a magmatic system, for a given element, among different minerals, and even within different-sized crystal grains of the very same mineral phase, is of fundamental importance in deepening our current understanding of magmatic differentiation processes. CFEC probably occurs more frequently in the natural world than either pure fractional or perfect equilibrium crystallisation alone, as a result of the interplay of varying diffusivities of elements under diverse physicochemical conditions, different residence time and growth rates of mineral phases in magmas, and varying grain sizes within each phase and among different phases. The marked systematic variations in trace element concentrations in the melts of the Bishop Tuff have long been perplexing and difficult to reconcile with existing models of differentiation. CFEC, which is able to better explain the scatter trends in a systematic way than fractional crystallisation, is considered to be the cause.

  20. Concurrent engineering teams. Volume 2: Annotated bibliography

    Science.gov (United States)

    Richter, Karen J.; Dierolf, David A.

    1990-11-01

    Specific concurrent engineering practices vary among organizations. There are, however, various management practices that appear to work well for most organizations. This paper presents the reader with specific, useful examples from several defense contractors illustrating how multifunctional concurrent engineering teams are being organized and managed and how concurrent engineering team meetings are conducted and supported. The types of computer support that could be used to enhance the efficiency and effectiveness of concurrent engineering team meetings are identified. The general findings are that there exists a direct relationship between total quality management (TQM) and concurrent engineering, and that many applications of computer-aided group problem solving are possible and practical today for the concurrent engineering team meetings. Areas identified for additional research are the documentation of the decision process and rationale during the product and process definition, the capturing of lessons learned during the implementation of concurrent engineering, and the performance evaluation and training of team members.

  1. Concurrent Delay in Construction Disputes

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    period of delay can potentially be attributed to several events falling within both parties' spheres of responsibility, commonly termed concurrent delay, is rarely regulated in construction contracts in spite of its common occurrence. This book analyses both the theoretical foundations and the practical......Delay is one of the issues most frequently encountered in today’s construction industry; it causes significant economic damage to all parties involved. Construction contracts, standard and bespoke, almost invariably consider delay from a perspective of single liability. If the event causing...

  2. Concurrent Delay in Construction Disputes

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    Delay is one of the issues most frequently encountered in today’s construction industry; it causes significant economic damage to all parties involved. Construction contracts, standard and bespoke, almost invariably consider delay from a perspective of single liability. If the event causing...... period of delay can potentially be attributed to several events falling within both parties' spheres of responsibility, commonly termed concurrent delay, is rarely regulated in construction contracts in spite of its common occurrence. This book analyses both the theoretical foundations and the practical...

  3. Barriers in Concurrent Separation Logic

    Science.gov (United States)

    Hobor, Aquinas; Gherghina, Cristian

    We develop and prove sound a concurrent separation logic for Pthreads-style barriers. Although Pthreads barriers are widely used in systems, and separation logic is widely used for verification, there has not been any effort to combine the two. Unlike locks and critical sections, Pthreads barriers enable simultaneous resource redistribution between multiple threads and are inherently stateful, leading to significant complications in the design of the logic and its soundness proof. We show how our logic can be applied to a specific example program in a modular way. Our proofs are machine-checked in Coq.

  4. Concurrent work with parents of adolescent patients.

    Science.gov (United States)

    Novick, Kerry Kelly; Novick, Jack

    2013-01-01

    Over the last ten years we have seen an increasing acceptance of the general idea of working with parents of child patients. What remains, however, as an area of controversy, conflict, and resistance, is the question of whether and how much therapists should or can work with the parents of adolescent patients. Questions cluster around how to maintain confidentiality and lead to the even larger issue of conceptualizing the developmental goals of the phase of adolescence. We see the major developmental tasks for both parents and adolescents as involving transformation of the self and the relationship, in the context of separateness rather than separation. If adolescent therapists work from the assumption that the goal of adolescence is transformation, concurrent work with parents and adolescents will move them all into a new level of relationship. Without concomitant change in parents, it is doubly hard for adolescents to progress into adulthood. In this paper we offer clinical material from five older adolescents and their parents to illustrate the techniques that follow from our model of dynamic concurrent parent work throughout the phases of treatment. Using the tasks of the therapeutic alliance as a conceptual framework, we describe working toward the dual goals of restoration to the path of progressive development and restoration of the parent-child relationship. We pay particular attention to the unfolding of conflicts between closed-system omnipotent functioning and open-system reality mastery, and the role offathers in late-adolescent development.

  5. Early upper digestive tract side effects of zidovudine with tenofovir plus emtricitabine in West African adults with high CD4 counts

    Directory of Open Access Journals (Sweden)

    Eric Ouattara

    2013-04-01

    Full Text Available Introduction: Tenofovir (TDF with emtricitabine (FTC and zidovudine (ZDV is a recognized alternate first-line antiretroviral (ART regimen for patients who cannot start treatment with non-nucleoside reverse transcriptase inhibitors (NNRTIs. Clinical studies comparing TDF+FTC+ZDV to other regimens are lacking. Methods: Participants in a trial of early ART in Côte d'Ivoire (Temprano ANRS 12136 started treatment with TDF/FTC plus either efavirenz (EFV or ZDV (HIV-1+2 dually infected patients and women refusing contraception or previously treated with nevirapine. We compared rates of upper digestive serious adverse events (sAEs between TDF/FTC+EFV and TDF/FTC+ZDV patients during the first six months of treatment. sAEs were defined as either grade 3–4 AEs or persistent grade 1–2 AEs leading to drug discontinuation. Results: A total of 197 patients (76% women, median CD4 count 395/mm3 started therapy with TDF/FTC, 126 with EFV and 71 with ZDV. During the first six months of ART, 94 patients had digestive AEs (nausea/vomiting of any grade (EFV 36/126, 29%; ZDV 58/71, 82%, p<0.0001, including 20 sAEs (EFV 3/126, 5%; ZDV 17/71, 24%, p<0.0001. In-patients on TDF/FTC+ZDV with digestive AEs, the median time to the first symptom was two days (IQR: 1–4. Plasma ZDV (Cmax distributions and pill ZDV dosages were normal. Patients with digestive AEs had higher haemoglobin levels and tended to have higher body mass indices and more frequent past histories of cotrimoxazole (CTX prophylaxis. Conclusions: We observed an unexpectedly high rate of digestive sAEs in West African adults, mostly women, who started a 3-nuc ART with TDF/FTC+ZDV in Côte d'Ivoire. These adults were participating in a trial of early ART and had much higher CD4 counts than those who currently routinely start ART in sub-Saharan Africa. They all received CTX concomitantly with ZDV. We suggest that further early prescriptions of TDF+XTC+ZDV should be carefully monitored and that whenever

  6. Use of accelerator mass spectrometry to measure the pharmacokinetics and peripheral blood mononuclear cell concentrations of zidovudine.

    Science.gov (United States)

    Vuong, Le T; Ruckle, Jon L; Blood, Arlin B; Reid, Michael J; Wasnich, Richard D; Synal, Hans-Arno; Dueker, Stephen R

    2008-07-01

    The remarkable sensitivity of accelerator mass spectrometry (AMS) is finding many new applications in pharmacology. In this study AMS was used to measure [(14)C]-Zidovudine (ZDV) concentrations at the drug's site of action (peripheral blood mononuclear cells, PBMCs) following a dose of 520 ng (less than one-millionth of the standard daily dose) to a healthy volunteer. In addition, the pharmacokinetics of this microdose were determined and compared to previously published parameters for therapeutic doses. Microdose ZDV pharmacokinetic parameters fell within reported 95% confidence intervals or standard deviations of most previously published values for therapeutic doses. Blood, urine, stool, saliva, and isolated PBMCs were collected periodically through 96 h postdose and analyzed for ZDV and metabolite concentrations. The results showed that ZDV is rapidly absorbed and eliminated, has one major metabolite, and is sequestered in PBMCs. (14)C mass balance assessments indicated a significant portion of ZDV remained after 96 h with a much prolonged elimination half-life. Results of this study demonstrate the usefulness of microdosing and AMS as a tool for studying the pharmacokinetic characteristics, including PBMC concentrations, of ZDV and underscore the value of AMS as a tool with which to perform pharmacokinetic and mass balance studies using trace amounts of radiolabeled compound.

  7. Acrolein enhances epigenetic modifications, FasL expression and hepatocyte toxicity induced by anti-HIV drug Zidovudine.

    Science.gov (United States)

    Ghare, Smita S; Donde, Hridgandh; Chen, Wei-Yang; Barker, David F; Gobejishvilli, Leila; McClain, Craig J; Barve, Shirish S; Joshi-Barve, Swati

    2016-09-01

    Zidovudine (AZT) remains the mainstay of antiretroviral therapy against HIV in resource-poor countries; however, its use is frequently associated with hepatotoxicity. Not all HIV patients on AZT develop hepatotoxicity, and the determining factors are unclear. Alcohol consumption and cigarette smoking are known risk factors for HIV hepatotoxicity, and both are significant sources of acrolein, a highly reactive and toxic aldehyde. This study examines the potential hepatotoxic interactions between acrolein and AZT. Our data demonstrate that acrolein markedly enhanced AZT-induced transcriptionally permissive histone modifications (H3K9Ac and H3K9Me3) allowing the recruitment of transcription factor NF-kB and RNA polymerase II at the FasL gene promoter, resulting in FasL upregulation and apoptosis in hepatocytes. Notably, the acrolein scavenger, hydralazine prevented these promoter-associated epigenetic changes and inhibited FasL upregulation and apoptosis induced by the combination of AZT and acrolein, as well as AZT alone. Our data strongly suggest that acrolein enhancement of promoter histone modifications and FasL upregulation are major pathogenic mechanisms driving AZT-induced hepatotoxicity. Moreover, these data also indicate the therapeutic potential of hydralazine in mitigating AZT hepatotoxicity.

  8. Amperometric sensing of anti-HIV drug zidovudine on Ag nanofilm-multiwalled carbon nanotubes modified glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Rafati, Amir Abbas, E-mail: aa_rafati@basu.ac.ir; Afraz, Ahmadreza

    2014-06-01

    The zidovudine (ZDV) is the first drug approved for the treatment of HIV virus infection. The detection and determination of this drug are very importance in human serum because of its undesirable effects. A new ZDV sensor was fabricated on the basis of nanocomposite of silver nanofilm (Ag-NF) and multiwalled carbon nanotubes (MWCNTs) immobilized on glassy carbon electrode (GCE). The modified electrodes were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), cyclic voltammetry (CV), and linear sweep voltammetry (LSV) techniques. Results showed that the electrodeposited silver has a nanofilm structure and further electrochemical studies showed that the prepared nanocomposite has high electrocatalytic activity and is appropriate for using in sensors. The amperometric technique under optimal conditions is used for the determination of ZDV ranging from 0.1 to 400 ppm (0.37 μM–1.5 mM) with a low detection limit of 0.04 ppm (0.15 μM) (S/N = 3) and good sensitivity. The prepared sensor possessed accurate and rapid response to ZDV and shows an average recovery of 98.6% in real samples. - Highlights: • New anti-HIV drug sensor was fabricated on the basis of nanomaterials composite. • The GCE modified by prepared hydrophilic MWCNT silver nanoparticles. • Silver nanofilm electrodeposited on MWCNT/GCE and characterized by SEM, EDX, CV and LSV • Response of electrode to ZDV was thoroughly investigated by electrochemical techniques.

  9. Implementing Concurrency Control in Reliable Distributed Object-Oriented Systems

    Science.gov (United States)

    Parrington, Graham D.; Shrivastava, Santosh K.

    One of the key concepts available in many object-oriented programming languages is that of type-inheritance, which permits new types to be derived from, and inherit the capabilities of, old types. This paper describes how to exploit this property in a very simple fashion to implement object-oriented concurrency control. We show how by using type-inheritance, objects may control their own level of concurrency in a type-specific manner. Simple examples demonstrate the applicability of the approach. The implementation technique described here is being used to develop Arjuna, a fault-tolerant distributed programming system supporting atomic actions.

  10. 47 CFR 61.136 - Revocation of concurrences.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Revocation of concurrences. 61.136 Section 61...) TARIFFS Concurrences § 61.136 Revocation of concurrences. A concurrence may be revoked by a revocation notice or cancelled by a new concurrence. A revocation notice or a new concurrence, if less broad...

  11. The fallacies of concurrent climate policy efforts.

    Science.gov (United States)

    Radetzki, Marian

    2010-05-01

    Climate policy has assumed an extreme degree of urgency in the international debate in recent years. This article begins by taking a critical look at the scientific underpinnings of the efforts to stabilize the climate. It points to several serious question marks on the purported relationship between greenhouse gas emissions and global warming, and expresses distrust about claims of impending catastrophes related to rising sea levels, hurricanes, and spread of infectious disease. It then reviews the concurrent climate policy efforts and concludes that they are incoherent, misguided and unduly costly, and that they have so far had no perceptible impact on anthropogenic greenhouse gas emissions. The exceedingly ambitious policy plans currently under preparation suffer from similar fallacies. For these reasons, but also because of the remaining scientific doubts and the exorbitant costs that have to be incurred, skepticism is expressed about the preparedness to implement the climate policy plans currently on the table.

  12. Distributed Management of Concurrent Web Service Transactions

    DEFF Research Database (Denmark)

    Alrifai, Mohammad; Dolog, Peter; Balke, Wolf-Tilo

    2009-01-01

    Business processes involve dynamic compositions of interleaved tasks. Therefore, ensuring reliable transactional processing of Web services is crucial for the success of Web service-based B2B and B2C applications. But the inherent autonomy and heterogeneity of Web services render the applicability...... of conventional ACID transaction models for Web services far from being straightforward. Current Web service transaction models relax the isolation property and rely on compensation mechanisms to ensure atomicity of business transactions in the presence of service failures. However, ensuring consistency...... in the open and dynamic environment of Web services, where interleaving business transactions enter and exit the system independently, remains an open issue. In this paper, we address this problem and propose an architecture that supports concurrency control on the Web services level. An extension...

  13. Concurrent Process Planning for Machined Parts

    Institute of Scientific and Technical Information of China (English)

    吴丹; 王先逵; 李志忠

    2002-01-01

    Detailed manufacturing information about the parts can help designers produce better designs. Detailed manufacturing information is conveyed to the designer through micro-circles within the concurrent design process for machined parts, focusing on instantaneous product design and process planning. The process has three key elements: a hierarchical architecture design of the concurrent process planning system, modeling and reengineering of the concurrent process planning, and modeling of information. The approach is successfully implemented and applied for concurrent design and process planning of some complicated parts.

  14. Automated Concurrent Blackboard System Generation in C++

    Science.gov (United States)

    Kaplan, J. A.; McManus, J. W.; Bynum, W. L.

    1999-01-01

    In his 1992 Ph.D. thesis, "Design and Analysis Techniques for Concurrent Blackboard Systems", John McManus defined several performance metrics for concurrent blackboard systems and developed a suite of tools for creating and analyzing such systems. These tools allow a user to analyze a concurrent blackboard system design and predict the performance of the system before any code is written. The design can be modified until simulated performance is satisfactory. Then, the code generator can be invoked to generate automatically all of the code required for the concurrent blackboard system except for the code implementing the functionality of each knowledge source. We have completed the port of the source code generator and a simulator for a concurrent blackboard system. The source code generator generates the necessary C++ source code to implement the concurrent blackboard system using Parallel Virtual Machine (PVM) running on a heterogeneous network of UNIX(trademark) workstations. The concurrent blackboard simulator uses the blackboard specification file to predict the performance of the concurrent blackboard design. The only part of the source code for the concurrent blackboard system that the user must supply is the code implementing the functionality of the knowledge sources.

  15. A Reference Framework for Concurrent Engineering

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Considering the diversity of methods and tools offered to concurrent engineering, the aspects playing important roles in the concurrent engineering c ontext have been pinpointed as being four core elements which are Activity, Meth od, Object and Information. Based on these four elements, a reference framework called AMOI is proposed to be the guideline for the systematic concurrent produc t design. Using the AMOI reference framework, concurrent product development sys tem can be structured into four function models (including the activity model, m ethod model, object model and information model) which are interconnected with e ach other.

  16. A Study on the Effects of the Rubric on Concurrent Discussion in Web-Based Environment

    Science.gov (United States)

    Jung, Jaewon

    2015-01-01

    The purpose of this study was to research the effect of the rubric on the level of learners' cognitive engagement and to explore the effectiveness of Web-based concurrent discussions experienced by learners. The participants were 20 undergraduate students of D Women's University and they were divided into six groups for concurrent discussions in…

  17. Concurrent radiochemotherapy in advanced hypopharyngeal cancer

    Directory of Open Access Journals (Sweden)

    Lukarski Dusko

    2010-05-01

    Full Text Available Abstract Background Concurrent platinum-based radiochemotherapy has been recommended as a standard of care in patients with locally advanced squamous cell head and neck carcinomas. Unfortunately, there is a lack of level one evidence on best treatment approach for advanced hypopharyngeal cancer. This report aims to summarize the results of our study on concurrent radiochemotherapy in patients with advanced hypopharyngeal cancer. Methods A retrospective analysis of 41 patients with stage III-IV hypopharyngeal cancer was performed. All patients were treated with three dimensional conformal radiotherapy and received 70 Gy in 35 fractions (2 Gy per fraction, 5 fractions per week. In dependence of the period when radiotherapy was realized, two different treatment techniques were used. Concurrent chemotherapy consisted of cisplatin 30 mg/m2 given on a weekly basis. Results The median age was 52 years (range 29-70. Stage IV disease was recognized in 73.2% of the patients. Complete response rates at the primary site and at the metastatic neck lymph nodes were 68.3% and 36.6%, respectively. A complete composite response was present in 27 patients (65.9%. Median follow-up was 13 months (range 7-36. Distant metastases as initial failure occurred in 7 patients (46.7%. The 2-year local relapse-free survival and regional relapse-free survival rates were 55.2% and 75.8%, respectively. The 2-year locoregional relapse-free survival rate was 51.3%. The 2-year disease-free survival and overall survival rates were 29.3% and 32.8%, respectively. Confluent mucositis was developed in 46.3% of patients. Leucopenia grade 1 was the most frequent hematological toxicity. The median weight loss at the end of treatment was 12% (range 5-21. The worst grade of late toxicity was most commonly pronounced in the skin and in the subcutaneous tissue. Conclusions Based on unsatisfactory results in our study we suggest that the use of sequential radiochemotherapy or chemotherapy

  18. Computational model predictions of cues for concurrent vowel identification.

    Science.gov (United States)

    Chintanpalli, Ananthakrishna; Ahlstrom, Jayne B; Dubno, Judy R

    2014-10-01

    Although differences in fundamental frequencies (F0s) between vowels are beneficial for their segregation and identification, listeners can still segregate and identify simultaneous vowels that have identical F0s, suggesting that additional cues are contributing, including formant frequency differences. The current perception and computational modeling study was designed to assess the contribution of F0 and formant difference cues for concurrent vowel identification. Younger adults with normal hearing listened to concurrent vowels over a wide range of levels (25-85 dB SPL) for conditions in which F0 was the same or different between vowel pairs. Vowel identification scores were poorer at the lowest and highest levels for each F0 condition, and F0 benefit was reduced at the lowest level as compared to higher levels. To understand the neural correlates underlying level-dependent changes in vowel identification, a computational auditory-nerve model was used to estimate formant and F0 difference cues under the same listening conditions. Template contrast and average localized synchronized rate predicted level-dependent changes in the strength of phase locking to F0s and formants of concurrent vowels, respectively. At lower levels, poorer F0 benefit may be attributed to poorer phase locking to both F0s, which resulted from lower firing rates of auditory-nerve fibers. At higher levels, poorer identification scores may relate to poorer phase locking to the second formant, due to synchrony capture by lower formants. These findings suggest that concurrent vowel identification may be partly influenced by level-dependent changes in phase locking of auditory-nerve fibers to F0s and formants of both vowels.

  19. Quantitative analysis of the effect of zidovudine, efavirenz, and ritonavir on insulin aggregation by multivariate curve resolution alternating least squares of infrared spectra

    Energy Technology Data Exchange (ETDEWEB)

    Marti-Aluja, Idoia; Ruisanchez, Itziar [Analytical and Organic Chemistry Department, Universitat Rovira i Virgili, Marcelli Domingo s/n, Campus Sescelades, 43007 Tarragona (Spain); Larrechi, M. Soledad, E-mail: mariasoledad.larrechi@urv.cat [Analytical and Organic Chemistry Department, Universitat Rovira i Virgili, Marcelli Domingo s/n, Campus Sescelades, 43007 Tarragona (Spain)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer The structure of insulin can be changed via interaction with antiretroviral drugs. Black-Right-Pointing-Pointer The chemical interaction promotes the formation of aggregates. Black-Right-Pointing-Pointer This drug effect was evaluated by MCR-ALS coupled to IR spectroscopy. Black-Right-Pointing-Pointer Formation of aggregates was favourable if drugs were able to form hydrogen bonds. Black-Right-Pointing-Pointer Higher drug concentrations favoured formation of amorphous aggregates. - Abstract: Quantification of the effect of antiretroviral drugs on the insulin aggregation process is an important area of research due to the serious metabolic diseases observed in AIDS patients after prolonged treatment with these drugs. In this work, multivariate curve resolution alternating least squares (MCR-ALS) was applied to infrared monitoring of the insulin aggregation process in the presence of three antiretroviral drugs to quantify their effect. To evidence concentration dependence in this process, mixtures at two different insulin:drug molar ratios were used. The interaction between insulin and each drug was analysed by {sup 1}H NMR spectroscopy. In all cases, the aggregation process was monitored during 45 min by infrared spectroscopy. The aggregates were further characterised by scanning electron microscopy (SEM). MCR-ALS provided the spectral and concentration profiles of the different insulin-drug conformations that are involved in the process. Their feasible band boundaries were calculated using the MCR-BANDS methodology. The kinetic profiles describe the aggregation pathway and the spectral profiles characterise the conformations involved. The retrieved results show that each of the three drugs modifies insulin conformation in a different way, promoting the formation of aggregates. Ritonavir shows the strongest promotion of aggregation, followed by efavirenz and zidovudine. In the studied concentration range, concentration

  20. Concurrent sexual partnerships among married Zimbabweans – implications for HIV prevention

    Directory of Open Access Journals (Sweden)

    Mugweni E

    2015-09-01

    Full Text Available Esther Mugweni,1 Stephen Pearson,2 Mayeh Omar2 1UCL Department of Infection and Population Health, University College London, London, 2The Nuffield Centre for International Health and Development, University of Leeds, Leeds, UK Background: Concurrent sexual partnerships play a key role in sustaining the HIV epidemic in Zimbabwe. Married couples are at an increased risk of contracting HIV from sexual networks produced by concurrent sexual partnerships. Addressing these partnerships is an international HIV prevention priority. Methods: Our qualitative study presents the socioeconomic factors that contribute to the occurrence of concurrent sexual partnerships among married people in Zimbabwe. We conducted 36 in-depth interviews and four focus group discussions with married men and women in Zimbabwe in 2008 to understand the organizations of concurrent sexual partnerships. Data were analyzed using framework analysis. Results: Our study indicates that relationship dissatisfaction played a key role in the engagement of concurrent sexual partnerships. Depending on the source of the dissatisfaction, there were four possible types of concurrent sexual relationships that were formed: sex worker, casual partner, regular girlfriend or informal polygyny which was referred to as “small house”. These relationships had different levels of intimacy, which had a bearing on practicing safer sex. Participants described three characteristics of hegemonic masculinity that contributed to the sources of dissatisfaction leading to concurrent sexual activity. Similarly, various aspects of emphasized femininity were described as creating opportunities for the occurrence of concurrent sexual relationships. Economic status was also listed as a factor that contributed to the occurrence of concurrent sexual partnerships. Conclusion: Marital dissatisfaction was indicated as a contributing factor to the occurrence of concurrent sexual relationships. There were several

  1. Investigation of the Role of Breast Cancer Resistance Protein (Bcrp/Abcg2) on Pharmacokinetics and Central Nervous System Penetration of Abacavir and Zidovudine in the Mouse

    Science.gov (United States)

    Giri, Nagdeep; Shaik, Naveed; Pan, Guoyu; Terasaki, Tetsuya; Mukai, Chisato; Kitagaki, Shinji; Miyakoshi, Naoki; Elmquist, William F.

    2016-01-01

    Many anti-human immunodeficiency virus 1 nucleoside reverse-transcriptase inhibitors have low central nervous system (CNS) distribution due in part to active efflux transport at the blood-brain barrier. We have previously shown that zidovudine (AZT) and abacavir (ABC) are in vitro substrates for the efflux transport protein breast cancer resistance protein (Bcrp) 1. We evaluated the influence of Bcrp1 on plasma pharmacokinetics and brain penetration of zidovudine and abacavir in wild-type and Bcrp1-deficient (Bcrp1−/−) FVB mice. There was no difference in either area under the concentration-time profiles for plasma (AUCplasma) or brain (AUCbrain) for zidovudine between the wild-type and Bcrp1−/− mice. The AUCplasma of abacavir was 20% lower in the Bcrp1−/− mice, whereas the AUCbrain was 20% greater. This difference resulted in a 1.5-fold increase in abacavir brain exposure in the Bcrp1−/− mice. The effect of selective and nonselective transport inhibitors on the ABC brain/plasma ratio at a single time point was evaluated. 3-(6-Isobutyl-9-methoxy-1,4-dioxo-1,2,3,4,6,7,12,12a-octahydropyrazino[1′,2′:1,6]pyrido[3,4-b]indol-3-yl)-propionicacid tert-butyl ester (Ko143), N[4[2-(6, 7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)ethyl]phenyl]-5-methoxy-9-oxo-10H-acridine-4-carboxamide (GF120918), probenecid, and Pluronic P85 increased abacavir plasma concentrations in the wild-type mice. Abacavir plasma concentrations in Bcrp1−/− mice were increased by (R)-4-((1aR,6R,10bS)-1,2-difluoro-1,1a,6,10b-tetrahydrodibenzo(a,e)cyclopropa(c)cycloheptan-6-yl)-α-((5-quinoloyloxy)methyl)-1-piperazineethanol trihydrochloride (LY335979), GF120918, and probenecid, but not by Ko143. Brain/plasma concentration ratios in both the wild-type and Bcrp1−/− mice were increased by the P-glycoprotein inhibitors LY335979 and GF120918, but not by BCRP-selective inhibitors. These data indicate that deletion of Bcrp1 has little influence on the pharmacokinetics or brain

  2. Nevirapine-Resistant HIV-1 DNA in Breast Milk After Single-Dose Nevirapine With or Without Zidovudine for Prevention of Mother-to-Child Transmission.

    Science.gov (United States)

    Gantt, Soren; Payant, Rachel; Carlsson, Jacquelyn; Micek, Mark A; Blanco, Ana Judith; Beck, Ingrid A; Matunha, Laurinda; Montoya, Pablo; Matediana, Eduardo; Gloyd, Stephen; Frenkel, Lisa M

    2012-09-01

    Among 30 human immunodeficiency virus type 1 (HIV-1)-infected women who received single-dose nevirapine (NVP), 17 (57%) had NVP-resistant HIV-1 detected in breast milk. NVP resistance in breast milk persisted for at least 8 months postpartum and was apparently transmitted to at least 1 infant. NVP resistance was detected less often in women who also received zidovudine. © The Author 2012. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Nanoassemblies containing a fluorouracil/zidovudine glyceryl prodrug with phospholipase A2-triggered drug release for cancer treatment.

    Science.gov (United States)

    Jin, Yiguang; Yang, Fang; Du, Lina

    2013-12-01

    Secretory phospholipase A2 (sPLA2), which is overexpressed in many tumors, cleaves ester bonds at the sn-2 position of phospholipids. A PLA2-sensitive amphiphilic prodrug, 1-O-octadecyl-2-(5-fluorouracil)-N-acetyl-3-zidovudine-phosphorylglycerol (OFZG), was synthesized and used to prepare nanoassemblies through the injection of a mixture of OFZG/cholesterol/Tween 80 (2:1:0.1, mol:mol:mol) into water. Cholesterol and Tween 80 was incorporated into the OFZG monolayers at the air/water interface to yield nanoassemblies. The resulting nanoassemblies exhibited a narrow size distribution with a mean size of 77.8nm and were stable due to their high surface charges. The in vitro experiments showed that PLA2 degraded OFZG. The nanoassemblies exhibited higher anticancer activity than the parent drug 5-fluorouracil (5-FU) in COLO205, HT-28, and HCT-116 cells. The intravenous (i.v.) administration of the nanoassemblies into mice resulted in the rapid elimination of OFZG from the circulation and its distribution mainly in the liver, lung, spleen, and kidney. After their injection into tumor-bearing mice, the nanoassemblies exhibited anticancer efficiency comparable to that of 5-FU, even though the nanoassemblies contained concentrations of only 1/10 of the molar amount of 5-FU. The lessons learned from the study and methods for the design of PLA2-sensitive amphiphilic prodrugs are also discussed. Enzyme-sensitive amphiphilic combinatorial prodrugs and prodrug-loaded nanoassemblies may represent a new strategy for anticancer drug design.

  4. Foscarnet, zidovudine and dolutegravir combination efficacy and tolerability for late stage HIV salvage therapy: A case-series experience.

    Science.gov (United States)

    Delory, Tristan; Papot, Emmanuelle; Rioux, Christophe; Charpentier, Charlotte; Auge-Courtoi, Claire; Michard, Florence; Peytavin, Gilles; Descamps, Diane; Matheron, Sophie; Yazdanpanah, Yazdan

    2016-07-01

    Salvage therapy including foscarnet (PFA), zidovudine (ZDV) and an optimized background ART (OBT) has been shown to be effective in patients with advanced HIV infection, and no therapeutic options. Dolutegravir (DTG) may offer a more active combination. Objective was to describe efficacy and tolerability of PFA-ZDV-DTG containing regimen. In our cohort, we identified patients who: (i) had plasma HIV-1 RNA load (pVL) >50 c/ml (>100 for HIV-2) on combination ART (cART); (ii) had at least 1 PI/r, 1 NRTI, 1 NNRTI (for HIV-1), and at least 1 raltegravir resistance mutations; (iii) were naive to DTG; and (iv) initiated on a PFA-ZDV-DTG containing-regimen with 48 weeks (W48) of follow-up. Out of 5 patients, 2 were infected with HIV-2. At PFA-ZDV-DTG initiation, CD4 cell count was (/mm(3) ) of 64, 40, 10, in HIV-1, and 37, 199, in HIV-2 infected patients; and pVL (log10 c/ml) of 4.8, 5.1, 4.4, in HIV-1, and 3.6, 4.2, in HIV-2 infected patients, respectively. Median OBT genotypic sensitivity score was 1.5 [1-2]. PFA was discontinued in one patient, due to an acute renal failure. At W48, one HIV-1 infected patient had a pVL 100 c/ml. No lack of treatment adherence was observed. In treatment experienced HIV-infected patients, failing cART and without other therapeutic options, a PFA-ZDV-DTG combination therapy could be effective. Renal adverse events should be monitored.

  5. Enhancement of zidovudine uptake by dehydroepiandrosterone sulfate in rat syncytiotrophoblast cell line TR-TBT 18d-1.

    Science.gov (United States)

    Nishimura, Tomohiro; Seki, Yoshiaki; Sato, Kazuko; Chishu, Takuya; Kose, Noriko; Terasaki, Tetsuya; Kang, Young-Sook; Sai, Yoshimichi; Nakashima, Emi

    2008-10-01

    AZT (3'-azido-3'-deoxythymidine; zidovudine), which is used for the prevention of mother-to-child transmission of HIV-1, is transplacentally transferred to the fetus across the blood-placenta barrier, which is composed of syncytiotrophoblasts. We recently showed that apical uptake of AZT by syncytiotrophoblasts is mediated by saturable transport system(s) in the TR-TBT 18d-1 cell line, and the cellular accumulation of AZT was increased in the presence of dehydroepiandrosterone sulfate (DHEAS). Here, we aimed to clarify the mechanism of this effect of DHEAS. Inhibitors of efflux transporters, including breast cancer resistance protein, P-glycoprotein, and multidrug resistance proteins, had little effect on the cellular accumulation of AZT in TR-TBT 18d-1. Kinetic study revealed that the rate constant for AZT uptake was greatly increased in the presence of 1 mM DHEAS. These results suggested that the effect of DHEAS was because of enhancement of the uptake process(es), rather than inhibition of efflux. When AZT uptake was analyzed according to the Michaelis-Menten equation, the estimated Michaelis constant, Km, for AZT uptake in the presence of 1 mM DHEAS was lower than that in its absence, whereas maximum uptake velocity, Vmax, and nonsaturable uptake clearance, kns, were similar in the presence and absence of DHEAS, indicating that DHEAS may change the recognition characteristics of the transporter for AZT in TR-TBT 18d-1. Thus, the increase of AZT uptake in TR-TBT 18d-1 cells in the presence of DHEAS was concluded to be because of a DHEAS-induced change in the affinity of AZT uptake system, although the transporter responsible for AZT uptake has not been identified.

  6. Concurrent partnerships and HIV: an inconvenient truth

    Directory of Open Access Journals (Sweden)

    Epstein Helen

    2011-03-01

    Full Text Available Abstract The strength of the evidence linking concurrency to HIV epidemic severity in southern and eastern Africa led the Joint United Nations Programme on HIV/AIDS and the Southern African Development Community in 2006 to conclude that high rates of concurrent sexual partnerships, combined with low rates of male circumcision and infrequent condom use, are major drivers of the AIDS epidemic in southern Africa. In a recent article in the Journal of the International AIDS Society, Larry Sawers and Eileen Stillwaggon attempt to challenge the evidence for the importance of concurrency and call for an end to research on the topic. However, their "systematic review of the evidence" is not an accurate summary of the research on concurrent partnerships and HIV, and it contains factual errors concerning the measurement and mathematical modelling of concurrency. Practical prevention-oriented research on concurrency is only just beginning. Most interventions to raise awareness about the risks of concurrency are less than two years old; few evaluations and no randomized-controlled trials of these programmes have been conducted. Determining whether these interventions can help people better assess their own risks and take steps to reduce them remains an important task for research. This kind of research is indeed the only way to obtain conclusive evidence on the role of concurrency, the programmes needed for effective prevention, the willingness of people to change behaviour, and the obstacles to change.

  7. Petri nets and other models of concurrency

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Sassone, Vladimiro

    1998-01-01

    This paper retraces, collects, and summarises contributions of the authors - in collaboration with others - on the theme of Petri nets and their categorical relationships to other models of concurrency.......This paper retraces, collects, and summarises contributions of the authors - in collaboration with others - on the theme of Petri nets and their categorical relationships to other models of concurrency....

  8. Safety and Liveness in Concurrent Pointer Programs

    NARCIS (Netherlands)

    Distefano, Dino; Katoen, Joost-Pieter; Rensink, Arend; Boer, de Frank S.; Bonsangue, Marcello M.; Graf, Susanne; Roever, de Willem-Paul

    2006-01-01

    The incorrect use of pointers is one of the most common source of software errors. Concurrency has a similar characteristic. Proving the correctness of concurrent pointer manipulating programs, let alone algorithmically, is a highly non-trivial task. This paper proposes an automated verification tec

  9. Steps in Modular Specifications for Concurrent Modules

    DEFF Research Database (Denmark)

    Da Rocha Pinto, Pedro; Dinsdale-Young, Thomas; Gardner, Philippa

    2015-01-01

    The specification of a concurrent program module is a difficult problem. The specifications must be strong enough to enable reasoning about the intended clients without reference to the underlying module implementation. We survey a range of verification techniques for specifying concurrent module...

  10. Concurrent sourcing and external supplier opportunism

    DEFF Research Database (Denmark)

    Mols, Niels Peter

    When a firm simultaneously makes and buys the same components then the firm uses concurrent sourcing. This paper presents an agency model for explaining how and when concurrent sourcing reduces the likelihood of external supplier opportunism. In the proposed model, the external supplier’s expected...

  11. Interval-based Specification of Concurrent Objects

    DEFF Research Database (Denmark)

    Løvengreen, Hans Henrik; Sørensen, Morten U.

    1998-01-01

    We propose a logic for specifying the behaviour of concurrent objects, ie. concurrent entities that invoke operation of each other. The logic is an interval logic whith operation invocatins as primitive formulas. The strengths and deficiencies of the logic are illustrated by specifying a variety...

  12. A Temporal Concurrent Constraint Programming Calculus

    DEFF Research Database (Denmark)

    Palamidessi, Catuscia; Valencia Posso, Frank Darwin

    2001-01-01

    The tcc model is a formalism for reactive concurrent constraint programming. In this paper we propose a model of temporal concurrent constraint programming which adds to tcc the capability of modeling asynchronous and non-deterministic timed behavior. We call this tcc extension the ntcc calculus...

  13. Lower Bounds of Concurrence for Multipartite States

    CERN Document Server

    Zhu, Xue-Na; Fei, Shao-Ming

    2012-01-01

    We study the entanglement of multipartite quantum states. Some lower bounds of the multipartite concurrence are reviewed. We further present more effective lower bounds for detecting and qualifying entanglement, by establishing functional relations between the concurrence and the generalized partial transpositions of the multipartite systems.

  14. New concurrent iterative methods with monotonic convergence

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Qingchuan [Michigan State Univ., East Lansing, MI (United States)

    1996-12-31

    This paper proposes the new concurrent iterative methods without using any derivatives for finding all zeros of polynomials simultaneously. The new methods are of monotonic convergence for both simple and multiple real-zeros of polynomials and are quadratically convergent. The corresponding accelerated concurrent iterative methods are obtained too. The new methods are good candidates for the application in solving symmetric eigenproblems.

  15. A Temporal Concurrent Constraint Programming Calculus

    DEFF Research Database (Denmark)

    Palamidessi, Catuscia; Valencia Posso, Frank Darwin

    2001-01-01

    The tcc model is a formalism for reactive concurrent constraint programming. In this paper we propose a model of temporal concurrent constraint programming which adds to tcc the capability of modeling asynchronous and non-deterministic timed behavior. We call this tcc extension the ntcc calculus...

  16. Gaudi components for concurrency: Concurrency for existing and future experiments

    Science.gov (United States)

    Clemencic, M.; Funke, D.; Hegner, B.; Mato, P.; Piparo, D.; Shapoval, I.

    2015-05-01

    HEP experiments produce enormous data sets at an ever-growing rate. To cope with the challenge posed by these data sets, experiments’ software needs to embrace all capabilities modern CPUs offer. With decreasing memory/core ratio, the one-process-per-core approach of recent years becomes less feasible. Instead, multi-threading with fine-grained parallelism needs to be exploited to benefit from memory sharing among threads. Gaudi is an experiment-independent data processing framework, used for instance by the ATLAS and LHCbexperiments at CERN's Large Hadron Collider. It has originally been designed with only sequential processing in mind. In a recent effort, the frame work has been extended to allow for multi-threaded processing. This includes components for concurrent scheduling of several algorithms - either processingthe same or multiple events, thread-safe data store access and resource management. In the sequential case, the relationships between algorithms are encoded implicitly in their pre-determined execution order. For parallel processing, these relationships need to be expressed explicitly, in order for the scheduler to be able to exploit maximum parallelism while respecting dependencies between algorithms. Therefore, means to express and automatically track these dependencies need to be provided by the framework. In this paper, we present components introduced to express and track dependencies of algorithms to deduce a precedence-constrained directed acyclic graph, which serves as basis for our algorithmically sophisticated scheduling approach for tasks with dynamic priorities. We introduce an incremental migration path for existing experiments towards parallel processing and highlight the benefits of explicit dependencies even in the sequential case, such as sanity checks and sequence optimization by graph analysis.

  17. How does concurrent sourcing affect performance?

    DEFF Research Database (Denmark)

    Mols, Niels Peter

    2010-01-01

    Abstract Purpose – “Concurrent sourcing” is a term used by Parmigiani to describe the phenomenon where a firm simultaneously buys and makes the same good or service. The purpose of this paper is to develop propositions that suggest how concurrent sourcing affects performance. Design....../methodology/approach – Based on transaction cost, agency, neoclassical economic, knowledge-based, and resource-based theory, it is proposed to show how concurrent sourcing affects performance. Findings – The paper argues that concurrent sourcing improves performance when firms face a combination of volume uncertainty......, technological uncertainty, performance uncertainty, non-decomposability, transaction-specific investments, and strong internal and external capabilities. Research limitations/implications – The paper maps the relationships between concurrent sourcing and performance and discusses how these relationships can...

  18. Multiparty Compatibility for Concurrent Objects

    Directory of Open Access Journals (Sweden)

    Roly Perera

    2016-06-01

    Full Text Available Objects and actors are communicating state machines, offering and consuming different services at different points in their lifecycle. Two complementary challenges arise when programming such systems. When objects interact, their state machines must be "compatible", so that services are requested only when they are available. Dually, when objects refine other objects, their state machines must be "compliant", so that services are honoured whenever they are promised. In this paper we show how the idea of multiparty compatibility from the session types literature can be applied to both of these problems. We present an untyped language in which concurrent objects are checked automatically for compatibility and compliance. For simple objects, checking can be exhaustive and has the feel of a type system. More complex objects can be partially validated via test cases, leading to a methodology closer to continuous testing. Our proof-of-concept implementation is limited in some important respects, but demonstrates the potential value of the approach and the relationship to existing software development practices.

  19. A Concurrency Control Algorithm in Multi-Version Multilevel DBMS

    Institute of Scientific and Technical Information of China (English)

    ZHANGMin; FENGDengguo

    2005-01-01

    The conventional transaction concurrency control theory and mechanisms are challenged in the context of a multilevel DBMS (Data base management system). Not only the correctness of transaction processing, namely the serializability of the transaction histories, but also the security properties should be followed. These requirements include diminishing the timing covert channels and preventing the starving problem in high-level transactions' unlimited waiting. In this paper we present a timestamp order based concurrency control algorithm that produce serializable histories by correctly combining all the 1SR histories generated by different level schedulers. We also provide an implementation scheduler algorithm based on snapshots. This approach is free from timing covert channels and transactions of different security levels have the same privilege to execute. In addition, this approach does not require the existence of a global trusted scheduler. Instead, it can be built on enhanced untrusted traditional multi-version schedulers, with the supplement of appropriate process towards read-down operations.

  20. Partnership duration, concurrency, and HIV in sub-Saharan Africa.

    Science.gov (United States)

    Sawers, Larry; Isaac, Alan

    2017-07-01

    A widely accepted explanation for the exceptionally high HIV prevalence in sub-Saharan Africa is the practice of long-term overlapping heterosexual partnering. This article shows that long-duration concurrent partnering can be protective against HIV transmission rather than promoting it. Monogamous partnering prevents sexual transmission to anyone outside the partnership and, in an initially concordant-seronegative partnership, prevents sexual acquisition of HIV by either partner. Those protections against transmission and acquisition last as long as the partnership persists without new outside partnerships. Correspondingly, these two protective effects characterise polygynous partnerships, whether or not the polygyny is formal or informal, until a partner initiates a new partnership. Stable and exclusive unions of any size protect against HIV transmission, and more durable unions provide a longer protective effect. Survey research provides little information on partnership duration in sub-Saharan Africa and sheds no light on the interaction of duration, concurrency, and HIV. This article shows how assumptions about partnership duration in individual-based sexual-network models affect the contours of simulated HIV epidemics. Longer mean partnership duration slows the pace at which simulated epidemics grow. With plausible assumptions about partnership duration and at levels of concurrency found in the region, simulated HIV epidemics grow slowly or not at all. Those results are consistent with the hypothesis that long-duration partnering is protective against HIV and inconsistent with the hypothesis that long-term concurrency drives the HIV epidemics in sub-Saharan Africa.

  1. Determinants of overweight with concurrent stunting among Ghanaian children.

    Science.gov (United States)

    Atsu, Benedicta K; Guure, Chris; Laar, Amos K

    2017-07-27

    Malnutrition (undernutrition and overnutrition) is a major public health problem in Ghana -affecting growth and development of individuals and the nation. Stunting and overweight are of particular interest, as recent national surveys show a rising trend of overnutrition and stubbornly high burden of stunting among Ghanaian children. There are currently no data on the simultaneous occurrence of overweight and stunting within individuals in Ghana. This paper presents the burden, the individual-level, and contextual determinants of overweight with concurrent stunting among Ghanaian children. This study analyzed data set of the fourth round of the Ghana Multiple Indicator Cluster Survey (MICS4). Bivariate analyses were used to describe selected characteristics of survey respondents and their children. Hierarchical modelling approach facilitated identification of significant distal, intermediate and proximal factors/determinants of concurrent stunting and overweight. Both crude and adjusted prevalence ratios via a multivariable Poison regression model with their corresponding 95% Confidence Intervals (CI) are reported. Variables with p ≤ 0.25 at the bivariate level were included in the multivariable analysis. An alpha value of 5% was used to indicate significance. Of 7550 cases (children) analyzed, the prevalence of stunting was 27.5%; underweight was 17.3%; and wasting was 7.7%. The prevalence of overweight and concurrent overweight and stunting were respectively 2.4% and 1.2%. Children who belonged to the fourth wealth quintile, were more likely to be overweight and concurrently stunted as against children belonging to the poorest quintile (aPR = 1.010; 95% CI, 1.003-1.017). Compared to religious (Christians/Muslim/Traditionalist) household heads, children whose household heads did not belong to any religion had 2 times the rates of the Overweight with concurrent stunting (PR = 2.024; 95% CI, 1.016-4.034). Children with mothers aged 20-34 and 35-49 had an

  2. [Clinical experience with zidovudine in patients with acquired immunodeficiency syndrome. Analysis of 117 cases. Grupo Andaluz para el Estudio de las Enfermedades Infecciosas].

    Science.gov (United States)

    Biedma, D; Bascuñana, A; Viciana, P; Causse, M; Torres Tortosa, M; Lozano de León, F; Pujol, E; Pachón, J

    1992-09-01

    In order to assess the efficacy and the toxicity of zidovudine in AIDS patients, we have studied, prospectively, 117 patients that were treated with this drug, in several andalusian hospitals between January 1988 and June 1990. Initial dose of the drug was 200 mg every 4 hours. Mean survival was 100% at 6 months and 66.5% at 23 months. Survival at 19 months was higher in ADVP (77%) than in non-ADVP (48%). A positive influence on weight. Karnofsky index and number of opportunistic infections during the six first months of treatment was recorded, benefit that was lost progressively from that moment onwards. Main adverse effects were hematological, 10.1% of the patients requiring transfusions due to hemoglobin lower than 6.5 gr%. The more frequent cause to stop therapy was severe neutropenia (less than 500 neutrophils per mm). We consider that the beneficial effect of zidovudine is only transient, diminishing gradually when the treatment is prolonged. At present doses adverse effects are moderate not being present in most of the patients.

  3. High-dose zidovudine plus valganciclovir for Kaposi sarcoma herpesvirus-associated multicentric Castleman disease: a pilot study of virus-activated cytotoxic therapy

    Science.gov (United States)

    Uldrick, Thomas S.; Polizzotto, Mark N.; Aleman, Karen; O'Mahony, Deirdre; Wyvill, Kathleen M.; Wang, Victoria; Marshall, Vickie; Pittaluga, Stefania; Steinberg, Seth M.; Tosato, Giovanna; Whitby, Denise; Little, Richard F.

    2011-01-01

    Kaposi sarcoma herpesvirus (KSHV)–associated multicentric Castleman disease (MCD) is a lymphoproliferative disorder most commonly observed in HIV-infected patients. It is characterized by KSHV-infected plasmablasts that frequently express lytic genes. Patients manifest inflammatory symptoms attributed to overproduction of KSHV viral IL-6, human IL-6, and human IL-6. There is no standard therapy and no established response criteria. We investigated an approach targeting 2 KSHV lytic genes, ORF36 and ORF21, the protein of which, respectively, phosphorylate ganciclovir and zidovudine to toxic moieties. In a pilot study, 14 HIV-infected patients with symptomatic KSHV-MCD received high-dose zidovudine (600 mg orally every 6 hours) and the oral prodrug, valganciclovir (900 mg orally every 12 hours). Responses were evaluated using new response criteria. A total of 86% of patients attained major clinical responses and 50% attained major biochemical responses. Median progression-free survival was 6 months. With 43 months of median follow-up, overall survival was 86% at 12 months and beyond. At the time of best response, the patients showed significant improvements in C-reactive protein, albumin, platelets, human IL-6, IL-10, and KSHV viral load. The most common toxicities were hematologic. These observations provide evidence that therapy designed to target cells with lytic KSHV replication has activity in KSHV-MCD. This trial was registered at www.clinicaltrials.gov as #NCT00099073. PMID:21487108

  4. Concurrent Manipulation of Expanded AVL Trees

    Institute of Scientific and Technical Information of China (English)

    章寅; 许卓群

    1998-01-01

    The concurrent manipulation of an expanded AVL tree(EAVL tree)s considered in this paper.The presented system can support any number of concurrent processes which perform searching,insertion and deletion on the tree.Simulation results indicate the high performance of the system.Elaborate techniques are used to achieve such a system unavailable based on any known algorithms.Methods developed in this paper may provide new insights into other problems in the area of concurrent search structure manipulation.

  5. A threaded Java concurrent implementation of the Monte-Carlo Metropolis Ising model.

    Science.gov (United States)

    Castañeda-Marroquín, Carlos; de la Puente, Alfonso Ortega; Alfonseca, Manuel; Glazier, James A; Swat, Maciej

    2009-06-01

    This paper describes a concurrent Java implementation of the Metropolis Monte-Carlo algorithm that is used in 2D Ising model simulations. The presented method uses threads, monitors, shared variables and high level concurrent constructs that hide the low level details. In our algorithm we assign one thread to handle one spin flip attempt at a time. We use special lattice site selection algorithm to avoid two or more threads working concurently in the region of the lattice that "belongs" to two or more different spins undergoing spin-flip transformation. Our approach does not depend on the current platform and maximizes concurrent use of the available resources.

  6. Higher rates of metabolic syndrome among women taking zidovudine as compared to tenofovir in rural Africa: preliminary data from the CART-1 study

    Directory of Open Access Journals (Sweden)

    Niklaus Daniel Labhardt

    2014-11-01

    Full Text Available Introduction: Due to its side effects stavudine (D4T has been replaced by zidovudine (AZT and tenofovir (TDF in most low- and middle-income countries (LMICs. In 2014 about 38% of adult first-line regimens contain AZT and 62% TDF [1]. Whereas the unfavourable metabolic outcomes of D4T in comparison to TDF have been described extensively, studies from LMICs comparing metabolic profiles between patients on AZT and TDF are scarce. Given the high number of patients in LMICs still taking AZT, data on their metabolic profile are needed. We present rates of metabolic syndrome (MS in adult patients taking either AZT- or TDF-containing first-line, non-nucleoside reverse transcriptase (NNRTI-based regimens. Materials and Methods: Data derived from a cross-sectional multi-disease screening conducted in ten facilities in two rural districts of Lesotho, Southern Africa [2]. Patients were eligible if aged ≥25 years and on NNRTI-containing first-line ART ≥6 months. The MS definition for Africa of the International Diabetes Federation was applied [3]. Assessed potential predictors for MS were age, time on ART, virologic suppression, body-mass index (BMI, alcohol consumption, wealth quintile, NNRTI (nevirapine (NVP or Efavirenz (EFV, history of previous D4T exposure and ART-backbone (AZT or TDF. Statistical analyses – stratified for sex – comprised univariate logistic regression for each predictor variable with subsequent construction of a multivariate model including all predictors with an association to MS at a significance level<0.1 in univariate analysis. Results: Out of 1026 patients, 660 (64.3% were female. MS prevalence was 9.8% (95% CI 6.9–13.4 in men and 22.9% (19.7–26.3 in women. In women, aged ≥35 years, AZT-backbone, NVP-base, BMI ≥25kg/m2 and taking ART for ≥4.5 years were associated with MS in univariate analysis. In the multivariate model only AZT (adjusted odds-ratio: 2.2, 95% CI 1.4–3.6; p=0.001 and BMI ≥25kg/m2 (9.8; 2.8

  7. Higher rates of metabolic syndrome among women taking zidovudine as compared to tenofovir in rural Africa: preliminary data from the CART-1 study

    Science.gov (United States)

    Labhardt, Niklaus Daniel; Cheleboi, Molisana; Faturyiele, Olatunbosun; Motlatsi, Mokete M; Pfeiffer, Karolin; Ismael Lejone, Thabo; Cerutti, Bernard; Muser, Jürgen; Shankar Gupta, Ravi; Lynen, Lutgarde; Hatz, Christoph

    2014-01-01

    Introduction Due to its side effects stavudine (D4T) has been replaced by zidovudine (AZT) and tenofovir (TDF) in most low- and middle-income countries (LMICs). In 2014 about 38% of adult first-line regimens contain AZT and 62% TDF [1]. Whereas the unfavourable metabolic outcomes of D4T in comparison to TDF have been described extensively, studies from LMICs comparing metabolic profiles between patients on AZT and TDF are scarce. Given the high number of patients in LMICs still taking AZT, data on their metabolic profile are needed. We present rates of metabolic syndrome (MS) in adult patients taking either AZT- or TDF-containing first-line, non-nucleoside reverse transcriptase (NNRTI)-based regimens. Materials and Methods Data derived from a cross-sectional multi-disease screening conducted in ten facilities in two rural districts of Lesotho, Southern Africa [2]. Patients were eligible if aged ≥25 years and on NNRTI-containing first-line ART ≥6 months. The MS definition for Africa of the International Diabetes Federation was applied [3]. Assessed potential predictors for MS were age, time on ART, virologic suppression, body-mass index (BMI), alcohol consumption, wealth quintile, NNRTI (nevirapine (NVP) or Efavirenz (EFV)), history of previous D4T exposure and ART-backbone (AZT or TDF). Statistical analyses – stratified for sex – comprised univariate logistic regression for each predictor variable with subsequent construction of a multivariate model including all predictors with an association to MS at a significance level<0.1 in univariate analysis. Results Out of 1026 patients, 660 (64.3%) were female. MS prevalence was 9.8% (95% CI 6.9–13.4) in men and 22.9% (19.7–26.3) in women. In women, aged ≥35 years, AZT-backbone, NVP-base, BMI ≥25kg/m2 and taking ART for ≥4.5 years were associated with MS in univariate analysis. In the multivariate model only AZT (adjusted odds-ratio: 2.2, 95% CI 1.4–3.6; p=0.001) and BMI ≥25kg/m2 (9.8; 2.8–34.1, p

  8. Similarity based mixed transaction concurrency control protocol

    Institute of Scientific and Technical Information of China (English)

    PAN Yi; LU Yan-sheng

    2005-01-01

    Due to the various performance requirements and data access restrictions of different types of real-time transactions, concurrency control protocols which had been designed for the systems with single type of transactions are not sufficient for mixed real-time database systems (MRTDBS), where different types of real-time transactions coexist in the systems concurrently. In this paper, a new concurrency control protocol MRTT_CC for mixed real-time transactions is proposed. The new strategy integrates with different concurrency control protocols to meet the deadline requirements of different types of real-time transactions. The data similarity concept is also explored in the new protocol to reduce the blocking time of soft real-time transactions, which increases their chances to meet the deadlines. Simulation experiments show that the new protocol has gained good performance.

  9. 33 CFR 385.7 - Concurrency statements.

    Science.gov (United States)

    2010-07-01

    ... DEFENSE PROGRAMMATIC REGULATIONS FOR THE COMPREHENSIVE EVERGLADES RESTORATION PLAN General Provisions § 385.7 Concurrency statements. The administrative record of the programmatic regulations in this part..., Jacksonville District, 701 San Marco Blvd., Jacksonville, Florida 32207, or by accessing the...

  10. Strategy Improvement for Concurrent Safety Games

    CERN Document Server

    Chatterjee, Krishnendu; Henzinger, Thomas A

    2008-01-01

    We consider concurrent games played on graphs. At every round of the game, each player simultaneously and independently selects a move; the moves jointly determine the transition to a successor state. Two basic objectives are the safety objective: ``stay forever in a set F of states'', and its dual, the reachability objective, ``reach a set R of states''. We present in this paper a strategy improvement algorithm for computing the value of a concurrent safety game, that is, the maximal probability with which player 1 can enforce the safety objective. The algorithm yields a sequence of player-1 strategies which ensure probabilities of winning that converge monotonically to the value of the safety game. The significance of the result is twofold. First, while strategy improvement algorithms were known for Markov decision processes and turn-based games, as well as for concurrent reachability games, this is the first strategy improvement algorithm for concurrent safety games. Second, and most importantly, the impro...

  11. Tools and Patterns for Dependable Concurrent Software

    NARCIS (Netherlands)

    Jovanovic, D.S.; Broenink, Johannes F.

    2005-01-01

    First, we give reasons for choosing a process-oriented approach for building complex concurrent systems. Upon a brief review of dependability attributes of software-supported systems, means for increasing dependability in process-oriented architectures are illustrated

  12. CilkSpec: Optimistic Concurrency for Cilk

    Energy Technology Data Exchange (ETDEWEB)

    Aga, Shaizeen D.; Krishnamoorthy, Sriram; Narayanasamy, Satish

    2015-11-15

    Recursive parallel programming models such as Cilk strive to simplify the task of parallel programming by enabling a simple divide-and-conquer model of programming. This model is effective in re- cursively partitioning work into smaller parts and combining their results. However, recursive work partitioning can impose additional constraints on concurrency than is implied by the true dependences in a program. In this paper, we present a speculation-based approach to alleviate the concurrency constraints imposed by such recursive parallel programs. We design a runtime infrastructure that supports speculative execution and a predictor to accurately learn and identify opportunities to relax extraneous concurrency constraints. Experimental evaluation demonstrates that speculative relaxation of concurrency constraints can deliver gains of up to 1.6× on 30 cores over baseline Cilk.

  13. Heterogeneous concurrent computing with exportable services

    Science.gov (United States)

    Sunderam, Vaidy

    1995-01-01

    Heterogeneous concurrent computing, based on the traditional process-oriented model, is approaching its functionality and performance limits. An alternative paradigm, based on the concept of services, supporting data driven computation, and built on a lightweight process infrastructure, is proposed to enhance the functional capabilities and the operational efficiency of heterogeneous network-based concurrent computing. TPVM is an experimental prototype system supporting exportable services, thread-based computation, and remote memory operations that is built as an extension of and an enhancement to the PVM concurrent computing system. TPVM offers a significantly different computing paradigm for network-based computing, while maintaining a close resemblance to the conventional PVM model in the interest of compatibility and ease of transition Preliminary experiences have demonstrated that the TPVM framework presents a natural yet powerful concurrent programming interface, while being capable of delivering performance improvements of upto thirty percent.

  14. Abstract Diagnosis for Timed Concurrent Constraint programs

    CERN Document Server

    Comini, Marco; Villanueva, Alicia

    2011-01-01

    The Timed Concurrent Constraint Language (tccp in short) is a concurrent logic language based on the simple but powerful concurrent constraint paradigm of Saraswat. In this paradigm, the notion of store-as-value is replaced by the notion of store-as-constraint, which introduces some differences w.r.t. other approaches to concurrency. In this paper, we provide a general framework for the debugging of tccp programs. To this end, we first present a new compact, bottom-up semantics for the language that is well suited for debugging and verification purposes in the context of reactive systems. We also provide an abstract semantics that allows us to effectively implement debugging algorithms based on abstract interpretation. Given a tccp program and a behavior specification, our debugging approach automatically detects whether the program satisfies the specification. This differs from other semiautomatic approaches to debugging and avoids the need to provide symptoms in advance. We show the efficacy of our approach...

  15. Inheritance and Synchronization in Concurrent OOP

    Science.gov (United States)

    Briot, Jean-Pierre; Yonezawa, Akinori

    This paper discusses knowledge sharing (inheritance) mechanisms for Object-Oriented Programming (OOP) in the context of concurrent (distributed) languages. We review three different schemes: inheritance, delegation and copy. A fourth model, called recipe-query, is presented and all are compared and criticized. Techniques relying on the shared memory assumption are rejected. We point out the conflict between distributing knowledge among objects and the synchronization of concurrent objects.

  16. A Concurrent Object-Oriented Language Ondine

    OpenAIRE

    Arisawa, Makoto; Ogihara, Takeshi; Kajihara, Yoichi

    1988-01-01

    A new concurrent object-oriented language Ondine is described. The Ondine design goals are strong information hiding within objects, concurrent programming, and pointerless programming. Ondine has ordinary control statements and types so that Ada or C programmers can easily handle it. By introducing by copy and by object assignment/argument passing, an Ondine object can be accessed from only one other object thus accomplishing pointerless structure. Ondine channels are used for constructing o...

  17. Noninterference for Concurrent Programs and Thread Systems

    OpenAIRE

    Boudol, Gérard; Castellani, Ilaria

    2001-01-01

    We propose a type system to ensure the property of noninterference in a system of concurrent programs, described in a standard imperative language enriched with parallelism. Our proposal is in the line of some recent work by Irvine, Volpano and Smith. Our type system seems more natural and less restrictive than that originally presented by these authors for the concurrent case. Moreover, we show how to extend the language in order to formalise scheduling policies for systems of sequential thr...

  18. Short-term Mobility and Increased Partnership Concurrency among Men in Zimbabwe.

    Directory of Open Access Journals (Sweden)

    Susan Cassels

    Full Text Available Migration has long been understood as an underlying factor for HIV transmission, and sexual partner concurrency has been increasingly studied as an important component of HIV transmission dynamics. However, less work has examined the role of short-term mobility in sexual partner concurrency using a network approach. Short-term mobility may be a risk for HIV for the migrant's partner as well either through the partner's risk behaviors while the migrant is away, such as the partner having additional partners, or via exposure to the return migrant.Using data from the 2010-11 Zimbabwe Demographic and Health Survey, weighted generalized linear regression models were used to investigate the associations between short-term mobility and partnership concurrency at the individual and partnership levels.At the individual level, we find strong evidence of an association between short-term mobility and concurrency. Men who traveled were more likely to have concurrent partnerships compared to men who did not travel and the relationship was non-linear: each trip was associated with a 2% higher probability of concurrency, with a diminishing risk at 60 trips (p<0.001. At the partnership level, short-term mobility by the male only or both partners was associated with male concurrency. Couples in which the female only traveled exhibited less male concurrency.Short-term mobility has the ability to impact population-level transmission dynamics by facilitating partnership concurrency and thus onward HIV transmission. Short-term migrants may be an important population to target for HIV testing, treatment, or social and behavioral interventions to prevent the spread of HIV.

  19. Theta oscillations accompanying concurrent auditory stream segregation.

    Science.gov (United States)

    Tóth, Brigitta; Kocsis, Zsuzsanna; Urbán, Gábor; Winkler, István

    2016-08-01

    The ability to isolate a single sound source among concurrent sources is crucial for veridical auditory perception. The present study investigated the event-related oscillations evoked by complex tones, which could be perceived as a single sound and tonal complexes with cues promoting the perception of two concurrent sounds by inharmonicity, onset asynchrony, and/or perceived source location difference of the components tones. In separate task conditions, participants performed a visual change detection task (visual control), watched a silent movie (passive listening) or reported for each tone whether they perceived one or two concurrent sounds (active listening). In two time windows, the amplitude of theta oscillation was modulated by the presence vs. absence of the cues: 60-350ms/6-8Hz (early) and 350-450ms/4-8Hz (late). The early response appeared both in the passive and the active listening conditions; it did not closely match the task performance; and it had a fronto-central scalp distribution. The late response was only elicited in the active listening condition; it closely matched the task performance; and it had a centro-parietal scalp distribution. The neural processes reflected by these responses are probably involved in the processing of concurrent sound segregation cues, in sound categorization, and response preparation and monitoring. The current results are compatible with the notion that theta oscillations mediate some of the processes involved in concurrent sound segregation.

  20. Effects of short-course zidovudine on the selection of nevirapine-resistant HIV-1 in women taking single-dose nevirapine.

    Science.gov (United States)

    Micek, Mark A; Blanco, Ana Judith; Carlsson, Jacquelyn; Beck, Ingrid A; Dross, Sandra; Matunha, Laurinda; Seidel, Kristy; Montoya, Pablo; Gantt, Soren; Matediana, Eduardo; Jamisse, Lilia; Gloyd, Stephen; Frenkel, Lisa M

    2012-06-15

    Single-dose nevirapine (sdNVP) given to prevent mother-to-child-transmission of HIV-1 selects NVP-resistance. Short-course zidovudine (ZDV) was hypothesized to lower rates of NVP-resistance. HIV-1 infected pregnant women administered sdNVP with or without short-course ZDV were assessed for HIV-1 mutations (K103N, Y181C, G190A, and V106M) prior to delivery and postpartum. Postpartum NVP-resistance was lower among 31 taking ZDV+sdNVP compared to 33 taking only sdNVP (35.5% vs. 72.7%; χ2 P = .003). NVP mutants decayed to <2% in 24/35 (68.6%) at a median 6 months postpartum, with no differences based on ZDV use (logrank P = .99). Short-course ZDV was associated with reduced NVP-resistance mutations among women taking sdNVP.

  1. Determination of the melting temperature, heat of fusion, and purity analysis of different samples of zidovudine (AZT using DSC

    Directory of Open Access Journals (Sweden)

    Adriano Antunes Souza Araújo

    2010-03-01

    Full Text Available The determination of chemical purity, melting range, and variation of enthalpy in the process of characterizing medicines is one of the principal requirements evaluated in quality control of the pharmaceutical industry. In this study, the method of purity determination using DSC was outlined, as well as the application of this technique for the evaluation of commercial samples of zidovudine (AZT (raw material supplied by different laboratories. To this end, samples from six different laboratories (A, B, C, D, E, and F and the standard reference (R from the United States Pharmacopeia (USP were analyzed. The DSC curves were obtained in the temperature range of 25 to 200 ºC under the dynamic atmosphere of N2 (50 mL min-1, heating rate of β=2 ºC min-1, using an Al capsule containing approximately 2 mg of sample material. The results demonstrated that the standard reference presented a proportion of 99.83% whereas the AZT samples presented a variation ranging from 97.59 to 99.54%. In addition, the standard reference was found to present a temperature of onset of melting point of 122.80 °C. Regarding the samples of active agents provided by the different laboratories, a variation ranging from 118.70 to 122.87 °C was measured. In terms of ΔHm, the samples presented an average value of 31.12 kJ mol-1.A determinação da pureza química, a faixa de fusão e a variação de entalpia envolvida no processo de caracterização de fármacos é um dos principais requisitos avaliados no controle de qualidade em indústrias farmacêuticas. Neste trabalho é feita uma breve abordagem sobre o método de determinação de pureza utilizando DSC, assim como a aplicação desta técnica para avaliação de amostras comerciais de zidovudina (AZT (matéria-prima fornecida por diferentes laboratórios. Para tal, foram analisadas amostras de seis diferentes laboratórios (A,B,C,D,E e F e a substância química de referência (R da United States Pharmacopeia (USP. As

  2. Lamivudine and Zidovudine

    Science.gov (United States)

    ... staying asleep excessive tiredness depression stuffy nose cough hair loss Some side effects can be serious. The ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

  3. Concurrent cerebellar and cervical intramedullary tuberculoma: Paradoxical response on antitubercular chemotherapy and need for surgery

    OpenAIRE

    Das, Kuntal Kanti; Jaiswal, Sushila; Shukla, Mukesh; Srivastava, Arun Kumar; Behari, Sanjay; Kumar,Raj

    2014-01-01

    Spinal intramedullary tuberculoma (SIT) is a rare manifestation of neurotuberculosis. Concurrent SIT and intracranial tuberculoma are further unusual. Most of these tuberculomas respond completely to medical therapy, and surgical excision is seldom required. In this report, we describe a 17-year-old boy who developed cervical intramedullary tuberculoma at C3-C6 level with a concurrent lesion involving the right cerebellar hemisphere while on treatment for tubercular meningitis. This patient h...

  4. An Algorithm to Construct Concurrent Reachability Graph of Petri Nets

    Institute of Scientific and Technical Information of China (English)

    张金泉; 倪丽娜; 蒋昌俊

    2004-01-01

    Reachability graph is a very important tool to analyze the dynamic properties of Petri nets, but the concurrent relation of transitions in Petri nets cannot be represented by reachability graph. Petri net is a concurrent system, while reachability graph is a serial one. However, concurrency is a kind of property which is not only very significant but also difficult to be analyzed and controlled. This paper presents the concepts of concurrent reachable marking and concurrent reachable graph in order to represent and analyze the concurrent system. The algorithm constructing concurrent reachable marking set and concurrent reachability graph is also shown so that we can study the response problems among services in a network computing environment and analyze the throughput of the system. The Dining Philosophers Problem, which is a classic problem of describing the management of concurrent resources, is given as an example to illustrate the significance of concurrent reachability graph.

  5. Concurrent Scheduling of Event-B Models

    CERN Document Server

    Boström, Pontus; Sere, Kaisa; Waldén, Marina; 10.4204/EPTCS.55.11

    2011-01-01

    Event-B is a refinement-based formal method that has been shown to be useful in developing concurrent and distributed programs. Large models can be decomposed into sub-models that can be refined semi-independently and executed in parallel. In this paper, we show how to introduce explicit control flow for the concurrent sub-models in the form of event schedules. We explore how schedules can be designed so that their application results in a correctness-preserving refinement step. For practical application, two patterns for schedule introduction are provided, together with their associated proof obligations. We demonstrate our method by applying it on the dining philosophers problem.

  6. Towards Interaction Reliability in Concurrent Applications

    Directory of Open Access Journals (Sweden)

    A. Silva

    2012-01-01

    Full Text Available Developing trustworthy concurrent applications is a seemingly never ending quest, which is necessary but difficult. It is necessary because mainstream systems and applications are inherently concurrent and they are pervasive to our daily life activities. It is difficult because such systems are inherently interactive and heterogeneous, so that boundaries can hardly be established for studying subsystems in isolation. Formal methods are a key instrument in resolving ambiguities and design reliable applications in a rigorous way. The authors overview major problems in the application of formal methods and outline how they are tackled by the papers collected in this volume.

  7. Concurrent sourcing and external supplier opportunism

    DEFF Research Database (Denmark)

    Mols, Niels Peter

    When a firm simultaneously makes and buys the same components then the firm uses concurrent sourcing. This paper presents an agency model for explaining how and when concurrent sourcing reduces the likelihood of external supplier opportunism. In the proposed model, the external supplier’s expected...... costs of opportunism are determined as a product of four factors. The four factors are: likelihood of discovering supplier opportunism, buyer’s internalized quantity as reaction to supplier opportunism, asset specificity of external supplier’s investments, and multiplicator effects. Each...

  8. Notes on Timed Concurrent Constraint Programming

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Valencia, Frank D.

    2004-01-01

    and program reactive systems. This note provides a comprehensive introduction to the background for and central notions from the theory of tccp. Furthermore, it surveys recent results on a particular tccp calculus, ntcc, and it provides a classification of the expressive power of various tccp languages.......A constraint is a piece of (partial) information on the values of the variables of a system. Concurrent constraint programming (ccp) is a model of concurrency in which agents (also called processes) interact by telling and asking information (constraints) to and from a shared store (a constraint...

  9. Micro-transactions for concurrent data structures

    DEFF Research Database (Denmark)

    Meawad, Fadi; Iyer, Karthik; Schoeberl, Martin;

    2013-01-01

    Transactional memory is a promising technique for enforcing disciplined access to shared data in a multiprocessor system. Transactional memory simplifies the implementation of a variety of concurrent data structures. In this paper, we study the benefits of a modest, real-time aware, hardware...... implementation of transactional memory that we call micro-transactions. In particular, we argue that hardware support for micro-transactions allows us to efficiently implement certain data structures. Those data structures are difficult to realize with the atomic operations provided by stock hardware and provide......, atomic instructions, and micro-transactions. Our results suggest that transactional memory is an interesting alternative to traditional concurrency control mechanisms....

  10. Concurrent Engineering in seafood product development

    DEFF Research Database (Denmark)

    Jonsdottir, Stella; Vesterager, Johan; Børresen, Torger

    1998-01-01

    Concurrent Engineering (CE) can provide an improved approach to product development for extending the lines of seafood products. Information technology support tools based on product models can provide an integrated and simultaneous approach for specifying new recipes. The seafood industry can...... benefit from the CE approach which can support product developers to provide concurrent specifications for raw materials, ingredients, packaging, and production methods. The approach involves the use of product models from which line extensions are more easily generated than by use of customary stepwise...

  11. The concurrent common Lisp development environment

    Science.gov (United States)

    1988-01-01

    A discussion of the Concurrent Common Lisp Development Environment on the iNTEL Personal Super Computer (iPSC) is presented. The advent of AI based engineering design tools has lead to a need for increased performance of computational facilities which support those tools. Gold Hill has approached this problem by directing its efforts to the creation of a concurrent, distributed AI development environment. This discussion focuses on the development tools aspect of the CCLISP environment. The future direction of Gold Hill in the area of distributed AI support environments is also presented.

  12. Compositional Formal Analysis for Concurrent Object-Oriented Languages

    OpenAIRE

    Tran, Thi Mai Thuong

    2013-01-01

    Concurrency is a ubiquitous phenomenon in modern software ranging from distributed systems communicating over the Internet to communicating processes running on multi-core processors and multi-processors. Therefore modern programming languages offer ways to program concurrency effectively. Still, writing correct concurrent programs is notoriously difficult because of the complexity of possible interactions between concurrent processes and because concurrency-related errors are often subtle an...

  13. Concurrent Meta-Evaluation: A Critique

    Science.gov (United States)

    Hanssen, Carl E.; Lawrenz, Frances; Dunet, Diane O.

    2008-01-01

    Meta-evaluations reported in the literature, although rare, often have focused on retrospective assessment of completed evaluations. Conducting a meta-evaluation concurrently with the evaluation modifies this approach. This method provides the opportunity for the meta-evaluators to advise the evaluators and provides the basis for a summative…

  14. CAPP Framework System for Concurrent Engineering

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Difficulty in generalizing and lack of adaptability are important factors that hamper a computer aided process planning (CAPP) system from being popular and practical. New manufacturing philosophies such as Concurrent Engineering require special characteristic of a CAPP system. Proposed in this paper is a CAPP framework system for Concurrent Engineering (CAPPFS-CE) which can meet the requirements of Concurrent Engineering and whose information models, function models and decision logic can be customized by users to form various CAPP application systems. Its function requirements are discussed broadly. An architecture for CAPPFS-CE is presented. It is based on abstract information models (AIMs) and abstract function models (AFMs). The kernel is formed by customization interpretation, internal process control and decision engine. A new information modeling and system development method, information element method (IEM), is introduced to build up AIMs, decision engine, and AFMs and then realize a CAPPFS-CE. THCAPP-SHELL, a CAPPFS-CE developed by IEM, is demonstrated. A CAPP system produced by customizing THCAPP-SHELL for complex structural parts in a concurrent engineering environment is shown.

  15. Logics and Games for True Concurrency

    CERN Document Server

    Gutierrez, Julian

    2010-01-01

    We study the underlying mathematical properties of various partial order models of concurrency based on transition systems, Petri nets, and event structures, and show that the concurrent behaviour of these systems can be captured in a uniform way by two simple and general dualities of local behaviour. Such dualities are used to define new mu-calculi and logic games for the analysis of concurrent systems with partial order semantics. Some results of this work are: the definition of a number of mu-calculi which, in some classes of systems, induce the same identifications as some of the best known bisimulation equivalences for concurrency; and the definition of (infinite) higher-order logic games for bisimulation and model-checking, where the players of the games are given (local) monadic second-order power on the sets of elements they are allowed to play. More specifically, we show that our games are sound and complete, and therefore, determined; moreover, they are decidable in the finite case and underpin nove...

  16. Declarative interpretations of session-based concurrency

    DEFF Research Database (Denmark)

    Cano, Mauricio; Rueda, Camilo; López-Acosta, Hugo-Andrés;

    2015-01-01

    Session-based concurrency is a type-based approach to the analysis of communication-intensive systems. Correct behavior in these systems may be specified in an operational or declarative style: the former defines how interactions are structured; the latter defines governing conditions. In this pa...

  17. Concurrent Engineering Design Using Intelligent Agents.

    Science.gov (United States)

    Parkinson, Brian

    1998-01-01

    Describes Design Builder, interactive multimedia software that was developed to enable undergraduate engineers to experience working in a concurrent environment without direct and specialized teaching-staff support, and to provide an interactive and intelligent simulation environment from which users may develop a culture that introduces…

  18. Concurrent Engineering in the 21st Century

    NARCIS (Netherlands)

    Stjepandic, Josip; Wognum, P.M.; Verhagen, Wim

    2015-01-01

    Presenting the gradual evolution of the concept of Concurrent Engineering (CE), and the technical, social methods and tools that have been developed, including the many theoretical and practical challenges that still exist, this book serves to summarize the achievements and current challenges of CE

  19. Concurrent Engineering Teams. Volume 2: Annotated Bibliography

    Science.gov (United States)

    1990-11-01

    Feigenbaum. A.V., Total Quality Control, McGraw-Hill Book Company, NY, 1983. Goldratt , Eliyahu and Jeff Cox, The Goal, A Process of Ongoing Improvement...design, namely concurrent engineering design for the life cycle. We introduce the emergent notion of Meta -Design, which we believe can be understood

  20. Formal Derivation of Concurrent Garbage Collectors

    NARCIS (Netherlands)

    Pavlovic, Dusko; Pepper, Peter; Smith, Douglas R.

    Concurrent garbage collectors are notoriously difficult to implement correctly. Previous approaches to the issue of producing correct collectors have mainly been based on posit-and-prove verification or on the application of domain-specific templates and transformations. We show how to derive the

  1. Concurrent Validity of a Pragmatic Protocol.

    Science.gov (United States)

    Duncan, Julie Condon; Perozzi, Joseph A.

    1987-01-01

    The scores of 11 non-handicapped kindergarten children on the Pragmatic Protocol (used in assessing language-handicapped children) were correlated with their ratings by five experienced judges on a 7-point equal-appearing interval scale of communicative competence. The concurrent validity of the Protocol and interobserver reliability were…

  2. On run-time exploitation of concurrency

    NARCIS (Netherlands)

    Hölzenspies, Philip Kaj Ferdinand

    2010-01-01

    The `free' speed-up stemming from ever increasing processor speed is over. Performance increase in computer systems can now only be achieved through parallelism. One of the biggest challenges in computer science is how to map applications onto parallel computers. Concurrency, seen as the set of v

  3. Concurrent Engineering Teams. Volume 1: Main Text

    Science.gov (United States)

    1990-11-01

    Delphi Processes. Scott, Foresman, and Co. Glenview, IL. Dertouzos, Michael L.; Lester, Rizhard K.; and Solow , Robert M. 1989. Made in America. Regaining...Nc:%* York. Nevins, James L. and Whitney, Daniel E. 1989. Concurrent Design of F-,oducts and Processes: a Strategy for the Next Generation in

  4. Nonlinear Inequalities and Entropy-Concurrence Plane

    CERN Document Server

    Bovino, F A

    2006-01-01

    Nonlinear inequalities based on the quadratic Renyi entropy for mixed two-qubit states are characterized on the Entropy-Concurrence plane. This class of inequalities is stronger than Clauser-Horne-Shimony-Holt (CHSH) inequalities and, in particular, are violated "in toto" by the set of Type I Maximally-Entangled-Mixture States (MEMS I).

  5. On run-time exploitation of concurrency

    NARCIS (Netherlands)

    Holzenspies, P.K.F.

    2010-01-01

    The `free' speed-up stemming from ever increasing processor speed is over. Performance increase in computer systems can now only be achieved through parallelism. One of the biggest challenges in computer science is how to map applications onto parallel computers. Concurrency, seen as the set of vali

  6. SCOOP Structured Concurrent Object Oriented Prolog

    Science.gov (United States)

    Vaucher, Jean; Lapalme, Guy; Malenfant, Jacques

    SCOOP is an experimental language implemented in Prolog that tries to combine the best of logic, object-oriented and concurrent programming in a structured, natural and efficient manner. SCOOP provides hierarchies of object classes. These objects behave as independent Prolog programs with private databases which can execute goals within other objects.

  7. Verifying Functional Behaviour of Concurrent Programs

    NARCIS (Netherlands)

    Zaharieva, M.; Huisman, Marieke; Blom, Stefan; Pearce, D.

    Specifying the functional behaviour of a concurrent program can often be quite troublesome: it is hard to provide a stable method contract that can not be invalidated by other threads. In this paper we propose a novel modular technique for specifying and verifying behavioural properties in

  8. Integrated concurrent utilization quality review, Part one.

    Science.gov (United States)

    Caterinicchio, R P

    1987-01-01

    This article is the first of a two-part series which argues for the concurrent management of the appropriateness, necessity, and quality of patient care. Intensifying scrutiny by the credentialing groups, the PROs and all third-party payors underscores the vital need to implement cost-effective information systems which integrate the departmentalized functions of patient-physician profiling, DRG case-mix analyses, length of stay monitoring, pre-admission/admission and continued stay review, discharge planning, risk management, incident reporting and quality review. In the domain of physician performance regarding admitting and practice patterns, the ability to exercise concurrent utilization-quality review means early detection and prevention of events which would otherwise result in denials of payment and/or compromised patient care. Concurrent utilization-quality review must, by definition, be managerially invasive and focused; hence, it is integral to maintaining the integrity of the services and product lines offered by the provider. In fact, if PPO status is a marketing agenda, then the institutional objectives of cost-effectiveness, productivity, value, and competitiveness can only be achieved through concurrent utilization-quality review.

  9. Influência da geometria da plataforma na determinação de chumbo em zidovudina (AZT por ET AAS Influence of the platform geometry on lead determination in zidovudine (AZT by ET AAS

    Directory of Open Access Journals (Sweden)

    Fátima R. Moreira

    2002-05-01

    Full Text Available The aim of this work was to compare the performances of the L'vov and integrated platforms in order to overcome the interferences found on lead determination in zidovudine by ET AAS. Pyrolysis and atomization temperatures found with integrated platform were 700 and 1400°C, respectively. The characteristic masses were 12.7 ± 1.2 pg with integrated platform and 11.1 ± 1.3 pg with grooved platform. The ratio between the slopes of zidovudine and aqueous curves shows a decrease in the interferences when the L'vov platform is used (bAZT/b aq = 0.97 ± 0.10 and the detection limit found was 0.03 µg.g-1. That ratio was 0.85 ± 0.07 with the integrated platform.

  10. Planning sentences while doing other things at the same time: effects of concurrent verbal and visuospatial working memory load.

    Science.gov (United States)

    Klaus, Jana; Mädebach, Andreas; Oppermann, Frank; Jescheniak, Jörg D

    2017-04-01

    This study investigated to what extent advance planning during sentence production is affected by a concurrent cognitive load. In two picture-word interference experiments in which participants produced subject-verb-object sentences while ignoring auditory distractor words, we assessed advance planning at a phonological (lexeme) and at an abstract-lexical (lemma) level under visuospatial or verbal working memory (WM) load. At the phonological level, subject and object nouns were found to be activated before speech onset with concurrent visuospatial WM load, but only subject nouns were found to be activated with concurrent verbal WM load, indicating a reduced planning scope as a function of type of WM load (Experiment 1). By contrast, at the abstract-lexical level, subject and object nouns were found to be activated regardless of type of concurrent load (Experiment 2). In both experiments, sentence planning had a more detrimental effect on concurrent verbal WM task performance than on concurrent visuospatial WM task performance. Overall, our results suggest that advance planning at the phonological level is more affected by a concurrently performed verbal WM task than advance planning at the abstract-lexical level. Also, they indicate an overlap of resources allocated to phonological planning in speech production and verbal WM.

  11. The effects of a motor and a cognitive concurrent task on walking in children with developmental coordination disorder.

    Science.gov (United States)

    Cherng, Rong-Ju; Liang, Ling-Yin; Chen, Yung-Jung; Chen, Jenn-Yeu

    2009-02-01

    The effects of type (cognitive vs. motor) and difficulty level (easy vs. hard) of a concurrent task on walking were examined in 10 boys and 4 girls (age 4-6 years) with developmental coordination disorder (DCD) and 28 age- and gender-matched unaffected children. Each child performed free walking (single task), walking while carrying an empty tray (dual task, the concurrent task being motor and easy), walking while carrying a tray with 7 marbles (the concurrent task being motor and hard), walking while repeating a series of digits forward (the concurrent task being cognitive and easy), and walking while repeating the digits backward (the concurrent task being cognitive and hard). Walking was affected by the concurrent task (i.e., dual-task cost) in the children with DCD more so than in the comparison children. Greater task difficulty also increased the dual-task cost in the children with DCD more so than in the comparison children. These patterns were only noted for the motor concurrent task. The cognitive concurrent task also affected walking, but the dual-task costs did not differ between difficulty levels, nor between the groups.

  12. Concurrent information affects response inhibition processes via the modulation of theta oscillations in cognitive control networks.

    Science.gov (United States)

    Chmielewski, Witold X; Mückschel, Moritz; Dippel, Gabriel; Beste, Christian

    2016-11-01

    Inhibiting responses is a challenge, where the outcome (partly) depends on the situational context. In everyday situations, response inhibition performance might be altered when irrelevant input is presented simultaneously with the information relevant for response inhibition. More specifically, irrelevant concurrent information may either brace or interfere with response-relevant information, depending on whether these inputs are redundant or conflicting. The aim of this study is to investigate neurophysiological mechanisms and the network underlying such modulations using EEG beamforming as method. The results show that in comparison to a baseline condition without concurrent information, response inhibition performance can be aggravated or facilitated by manipulating the extent of conflict via concurrent input. This depends on whether the requirement for cognitive control is high, as in conflicting trials, or whether it is low, as in redundant trials. In line with this, the total theta frequency power decreases in a right hemispheric orbitofrontal response inhibition network including the SFG, MFG, and SMA, when concurrent redundant information facilitates response inhibition processes. Vice versa, theta activity in a left-hemispheric response inhibition network (i.e., SFG, MFG, and IFG) increases, when conflicting concurrent information compromises response inhibition processes. We conclude that concurrent information bi-directionally shifts response inhibition performance and modulates the network architecture underlying theta oscillations which are signaling different levels of the need for cognitive control.

  13. Aerospace concurrent engineering: a modern global approach

    Science.gov (United States)

    Imbert, Mariano; Li, Xiaoxing

    2009-12-01

    System engineering aspects, like concurrent engineering (CE) in the aerospace sector, has been studied by many authors. The change and evolution in this regard is continually influenced by the information technology advances. But global cooperation is only discussed by developed countries and high technology corporations. A review of CE and its ramifications in the aerospace industry is presented. Based on the current literature, the general lifecycle of a spacecraft and its phases are explained as well as the tools that are implemented in today's industry. In this paper we propose a new approach for the product development process in the spacecraft production industry the Aerospace Concurrent Engineering (ACE), which is mainly focused in the technology itself, its optimal design and environment impact rather than costs and marketing impact. And the potential of globally oriented research and implementation of space programs is discussed for its consideration.

  14. Transactions Concurrency Control in Web Service Environment

    DEFF Research Database (Denmark)

    Alrifai, Mohammad; Dolog, Peter; Nejdl, Wolfgang

    2006-01-01

    an engineering point of view as it does not change the way consumers or clients of web services have to be programmed. Furthermore, it avoids direct communication between transaction coordinators which preserves security by keeping the information about business transactions restricted to the coordinators which......Business transactions in web service environments run with relaxed isolation and atomicity property. In such environments, transactions can commit and roll back independently on each other. Transaction management has to reflect this issue and address the problems which result for example from...... concurrent access to web service resources and data. In this paper we propose an extension to the WS-Transaction Protocol which ensures the consistency of the data when independent business transactions access the data concurrently under the relaxed transaction properties. Our extension is based...

  15. Nautilus: A Concurrent Anticipatory Programming Language

    Science.gov (United States)

    Menezes, P. Blauth; Costa, Simone A.; Machado, Júlio P.; Ramos, Jaime

    2002-09-01

    Nautilus is a concurrent anticipatory programming language based on the object-oriented language GNOME which is a simplified and revised version of OBLOG. A semantics for Nautilus is given by Nonsequencial Automata, that is a categorial semantic domain based on labeled transition system with full concurrency, where a class of morphisms stands for anticipation. The semantics of an object in Nautilus is given by an anticipation morphism, which is viewed as a special automaton morphism where target automata, called base, is determined by the computations of a freely generated automata able to simulate any object specified over the involved attributes, and the source automata is a relabelled restriction of the base. In order to introduce the anticipation of Nautilus, some examples are presented depicting the features of the language.

  16. Transparent concurrent execution of mutually exclusive alternatives

    OpenAIRE

    Smith, Jonathan M.; Gerald Q. Maguire Jr.

    1988-01-01

    We examine the task of concurrently computing alternative solutions to a problem. We restrict our interest to the case where only one of the solutions is needed; in this case we need some rule for selecting between the solutions. We use "fastest first," where the first successful alternative is selected. For problems where the required execution time is unpredictable, such as database queries. this method can show substantial execution time performance increases. These increases are dependent...

  17. Concurrency Control Mechanism of Complex Objects

    Institute of Scientific and Technical Information of China (English)

    徐庆云; 王能斌

    1992-01-01

    A complex object is an abstraction and description of a complex entity of the real world.Many applications in such domains as CIMS,CAD and OA define and manipulate a complex object as a single unit.In this paper,a definition of the model of complex objects is given,and the concurrency control mechanism of complex objects in WHYMX object-oriented database system is described.

  18. Verification of concurrent programs with Chalice

    OpenAIRE

    K. Rustan M. Leino; Müller, Peter; Smans, Jan

    2009-01-01

    A program verifier is a tool that allows developers to prove that their code satisfies its specification for every possible input and every thread schedule. These lecture notes describe a verifier for concurrent programs called Chalice. Chalice's verification methodology centers around permissions and permission transfer. In particular, a memory location may be accessed by a thread only if that thread has permission to do so. Proper use of permissions allows Chalice to deduce upper bound...

  19. Preliminary Proceedings 15th International Workshop on Expressiveness in Concurrency

    DEFF Research Database (Denmark)

    The EXPRESS workshops aim at bringing together researchers interested in the relations between various formal systems, particularly in the field of Concurrency. More specifically, they focus on the comparison between programming concepts (such as concurrent, functional, imperative, logic and object...

  20. Construction disputes in Denmark: the case of concurrent delay

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    2015-01-01

    Through a case study of decisions on concurrent delay, the article discusses the defining features of Danish construction arbitration.......Through a case study of decisions on concurrent delay, the article discusses the defining features of Danish construction arbitration....

  1. A Framework of Concurrent Mechanism Based on Java Multithread

    Directory of Open Access Journals (Sweden)

    Wuxue Jiang

    2013-09-01

    Full Text Available The continuously increased demand for paralleling multitask in domains such as grid computing and cloud computing has significantly promoted research on concurrent mechanism and concurrent programming. The Java programming language supports multithread mechanism for developing paralleling programs, however, it is difficult to apply Java concurrent primitives to specific problems. Thus, for the development of high reliable and qualitative Java concurrent programs, this paper analyses Java multithread mechanism and it’s realization, studies the concurrent mechanism based on Java synchronization and interactive communication mechanism , compares the concurrent structure based on operating system and based on Java multithread, sums up some concurrent programming rules and strategies to prevent deadlock. A frame instance based on entire synchronization is presented, which can help to develop concurrent programs quickly.  

  2. Managing Asynchronous Data in ATLAS's Concurrent Framework

    CERN Document Server

    Leggett, Charles; The ATLAS collaboration

    2016-01-01

    In order to be able to make effective use of emerging hardware, where the amount of memory available to any CPU is rapidly decreasing as the core count continues to rise, ATLAS has begun a migration to a concurrent, multi-threaded software framework, known as AthenaMT. Significant progress has been made in implementing AthenaMT - we can currently run realistic Geant4 simulations on massively concurrent machines. the migration of realistic prototypes of reconstruction workflows is more difficult, given the large amounts of legacy code and the complexity and challenges of reconstruction software. These types of workflows, however, are the types that will most benefit from the memory reduction features of a multi-threaded framework. One of the challenges that we will report on in this paper is the re-design and implementation of several key asynchronous technologies whose behaviour is radically different in a concurrent environment than in a serial one, namely the management of Conditions data and the Detector D...

  3. Symbolic Analysis of Concurrent Programs with Polymorphism

    Science.gov (United States)

    Rungta, Neha Shyam

    2010-01-01

    The current trend of multi-core and multi-processor computing is causing a paradigm shift from inherently sequential to highly concurrent and parallel applications. Certain thread interleavings, data input values, or combinations of both often cause errors in the system. Systematic verification techniques such as explicit state model checking and symbolic execution are extensively used to detect errors in such systems [7, 9]. Explicit state model checking enumerates possible thread schedules and input data values of a program in order to check for errors [3, 9]. To partially mitigate the state space explosion from data input values, symbolic execution techniques substitute data input values with symbolic values [5, 7, 6]. Explicit state model checking and symbolic execution techniques used in conjunction with exhaustive search techniques such as depth-first search are unable to detect errors in medium to large-sized concurrent programs because the number of behaviors caused by data and thread non-determinism is extremely large. We present an overview of abstraction-guided symbolic execution for concurrent programs that detects errors manifested by a combination of thread schedules and data values [8]. The technique generates a set of key program locations relevant in testing the reachability of the target locations. The symbolic execution is then guided along these locations in an attempt to generate a feasible execution path to the error state. This allows the execution to focus in parts of the behavior space more likely to contain an error.

  4. Managing Asynchronous Data in ATLAS's Concurrent Framework

    CERN Document Server

    Baines, John; The ATLAS collaboration

    2016-01-01

    In order to be able to make effective use of emerging hardware, where the amount of memory available to any CPU is rapidly decreasing as the core count continues to rise, ATLAS has begun a migration to a concurrent, multi-threaded software framework, known as AthenaMT. Significant progress has been made in implementing AthenaMT - we can currently run realistic Geant4 simulations on massively concurrent machines. the migration of realistic prototypes of reconstruction workflows is more difficult, given the large amounts of legacy code and the complexity and challenges of reconstruction software. These types of workflows, however, are the types that will most benefit from the memory reduction features of a multi-threaded framework. One of the challenges that we will report on in this paper is the re-design and implementation of several key asynchronous technologies whose behaviour is radically different in a concurrent environment than in a serial one, namely the management of Conditions data and the Detector D...

  5. Concurrent sexual partnerships do not explain the HIV epidemics in Africa: a systematic review of the evidence

    Directory of Open Access Journals (Sweden)

    Sawers Larry

    2010-09-01

    Full Text Available Abstract The notion that concurrent sexual partnerships are especially common in sub-Saharan Africa and explain the region's high HIV prevalence is accepted by many as conventional wisdom. In this paper, we evaluate the quantitative and qualitative evidence offered by the principal proponents of the concurrency hypothesis and analyze the mathematical model they use to establish the plausibility of the hypothesis. We find that research seeking to establish a statistical correlation between concurrency and HIV prevalence either finds no correlation or has important limitations. Furthermore, in order to simulate rapid spread of HIV, mathematical models require unrealistic assumptions about frequency of sexual contact, gender symmetry, levels of concurrency, and per-act transmission rates. Moreover, quantitative evidence cited by proponents of the concurrency hypothesis is unconvincing since they exclude Demographic and Health Surveys and other data showing that concurrency in Africa is low, make broad statements about non-African concurrency based on very few surveys, report data incorrectly, report data from studies that have no information about concurrency as though they supported the hypothesis, report incomparable data and cite unpublished or unavailable studies. Qualitative evidence offered by proponents of the hypothesis is irrelevant since, among other reasons, there is no comparison of Africa with other regions. Promoters of the concurrency hypothesis have failed to establish that concurrency is unusually prevalent in Africa or that the kinds of concurrent partnerships found in Africa produce more rapid spread of HIV than other forms of sexual behaviour. Policy makers should turn attention to drivers of African HIV epidemics that are policy sensitive and for which there is substantial epidemiological evidence.

  6. Concurrent sexual partnerships do not explain the HIV epidemics in Africa: a systematic review of the evidence.

    Science.gov (United States)

    Sawers, Larry; Stillwaggon, Eileen

    2010-09-13

    The notion that concurrent sexual partnerships are especially common in sub-Saharan Africa and explain the region's high HIV prevalence is accepted by many as conventional wisdom. In this paper, we evaluate the quantitative and qualitative evidence offered by the principal proponents of the concurrency hypothesis and analyze the mathematical model they use to establish the plausibility of the hypothesis.We find that research seeking to establish a statistical correlation between concurrency and HIV prevalence either finds no correlation or has important limitations. Furthermore, in order to simulate rapid spread of HIV, mathematical models require unrealistic assumptions about frequency of sexual contact, gender symmetry, levels of concurrency, and per-act transmission rates. Moreover, quantitative evidence cited by proponents of the concurrency hypothesis is unconvincing since they exclude Demographic and Health Surveys and other data showing that concurrency in Africa is low, make broad statements about non-African concurrency based on very few surveys, report data incorrectly, report data from studies that have no information about concurrency as though they supported the hypothesis, report incomparable data and cite unpublished or unavailable studies. Qualitative evidence offered by proponents of the hypothesis is irrelevant since, among other reasons, there is no comparison of Africa with other regions.Promoters of the concurrency hypothesis have failed to establish that concurrency is unusually prevalent in Africa or that the kinds of concurrent partnerships found in Africa produce more rapid spread of HIV than other forms of sexual behaviour. Policy makers should turn attention to drivers of African HIV epidemics that are policy sensitive and for which there is substantial epidemiological evidence.

  7. Concurrent object-oriented programming: a visualization challenge

    Science.gov (United States)

    Widjaja, Hendra; Oudshoorn, Michael J.

    1997-04-01

    Understanding and subsequently fine-tuning concurrent object-oriented programs may be difficult. To alleviate this situation, program visualization can be used. This research focuses on the question of what and how such visualization can be done for concurrent object-oriented systems. Furthermore, in the absence of language support, to what extent such visualization can be realized. To investigate these issues, Visor++, a tool for visualizing CC++ programs, is developed. This research proposes that both static and dynamic views of programs are important. However, many languages, including CC++, do not provide adequate support for program visualization. CC++, in particular, provides rudimentary support which is available only in the low-level run-time system. Therefore, proper support must be facilitated by Visor++. To make such support portable and maintainable, it is provided at the CC++ source-code level. Although some information, such as changes in variable and data structure values, cannot be easily captured by such an approach, experiments with Visor++ have shown that the information obtained can be of valuable assistance for understanding and fine-tuning programs.

  8. Quantitative measurement of hypertrophic scar: interrater reliability and concurrent validity.

    Science.gov (United States)

    Nedelec, Bernadette; Correa, José A; Rachelska, Grazyna; Armour, Alexis; LaSalle, Léo

    2008-01-01

    Research into the pathophysiology and treatment of hypertrophic scar (HSc) remains limited by the heterogeneity of scar and the imprecision with which its severity is measured. The objective of this study was to test the interrater reliability and concurrent validity of the Cutometer measurement of elasticity, the Mexameter measurement of erythema and pigmentation, and total thickness measure of the DermaScan C relative to the modified Vancouver Scar Scale (mVSS) in patient-matched normal skin, normal scar, and HSc. Three independent investigators evaluated 128 sites (severe HSc, moderate or mild HSc, donor site, and normal skin) on 32 burn survivors using all of the above measurement tools. The intraclass correlation coefficient, which was used to measure interrater reliability, reflects the inherent amount of error in the measure and is considered acceptable when it is >0.75. Interrater reliability of the totals of the height, pliability, and vascularity subscales of the mVSS fell below the acceptable limit ( congruent with0.50). The individual subscales of the mVSS fell well below the acceptable level (0.89) for each study site with the exception of severe scar. Mexameter and DermaScan C reliability measurements were acceptable for all sites (>0.82). Concurrent validity correlations with the mVSS were significant except for the comparison of the mVSS pliability subscale and the Cutometer maximum deformation measure comparison in severe scar. In conclusion, the Mexameter and DermaScan C measurements of scar color and thickness of all sites, as well as the Cutometer measurement of elasticity in all but the most severe scars shows high interrater reliability. Their significant concurrent validity with the mVSS confirms that these tools are measuring the same traits as the mVSS, and in a more objective way.

  9. A randomized, controlled trial of initial anti-retroviral therapy with abacavir/lamivudine/zidovudine twice-daily compared to atazanavir once-daily with lamivudine/zidovudine twice-daily in HIV-infected patients over 48 weeks (ESS100327, the ACTION Study

    Directory of Open Access Journals (Sweden)

    McClernon Daniel

    2009-04-01

    Full Text Available Abstract Background Traditional first line regimens containing a non-nucleoside reverse transcriptase inhibitor or protease inhibitor may not be suitable for a subset of antiretroviral-naïve patients such as those with certain co-morbidities, women of child-bearing potential, and intolerability to components of standard first line therapy. This study was conducted to determine if alternate treatment options may meet the needs of both general and special patient populations. The ACTION study was a randomized, open-label, multicenter, 48-week trial that compared the safety and efficacy of a triple nucleoside regimen versus a protease inhibitor plus a dual nucleoside regimen in HIV-1 treatment-naïve subjects. Results 279 HIV-infected subjects with HIV-1 RNA (VL >5000 but 3 were randomized (1:1 to receive abacavir sulfate/lamivudine/zidovudine (ABC/3TC/ZDV twice-daily or atazanavir (ATV once-daily plus lamivudine/zidovudine (3TC/ZDV twice-daily. Protocol-defined virologic failure was based on multiple failure criteria. Non-inferiority of ABC/3TC/ZDV to ATV+3TC/ZDV was established with 62% vs. 59% of subjects achieving a VL Conclusion ABC/3TC/ZDV demonstrated comparable virologic efficacy to ATV+3TC/ZDV in this population over 48 weeks. In those with a baseline VL ≥ 100,000 c/mL, subjects in the ATV+3TC/ZDV showed better virologic efficacy. Both regimens offer benefits in select therapy-naïve subjects. Trial Registration [Clinical Trials Identifier, NCT00082394].

  10. Simultaneous quantitation of lamivudine, zidovudine and nevirapine in human plasma by liquid chromatography–tandem mass spectrometry and application to a pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    Murali Krishna Matta

    2012-10-01

    Full Text Available A rapid and sensitive LC–MS/MS method for the simultaneous quantitation of lamivudine, zidovudine and nevirapine in human plasma using abacavir as internal standard has been developed and validated. The analytes and IS were extracted from plasma by solid phase extraction using Oasis HLB cartridges and separated on a Hypurity Advance C18 column using a mixture of acetonitrile:0.1% formic acid (76:24, v/v at a flow rate of 0.8 mL/min. Detection involved an API-4000 LC–MS/MS with electrospray ionization in the positive ion mode and multiple-reaction monitoring for analysis. The method was validated according to FDA guidelines and shown to provide intra- and inter-day precision and accuracy within acceptable limits in a run time of only 3.5 min. The method was successfully applied to a pharmacokinetic study involving a single oral administration of a combination tablet to human male volunteers.

  11. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

    Science.gov (United States)

    K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Creating components object oriented, concurrent, and distributed computing in Java

    CERN Document Server

    Kann, Charles W

    2003-01-01

    INTRODUCTION TO CONCURRENT PROGRAMMING AND COMPONENTSChapter GoalsWhat is Concurrent Programming?ComponentsTypes of Concurrent ProgrammingTHREADS AND PROGRAM CONTEXTSWriting threads in JavaA Simple Execution ModelProgram SafetyDeadlockDESIGNING AND IMPLEMENTING CONCURRENT PROGRAMS WITH STATE DIAGRAMSBackgroundSteps to Create a Concurrent ProgramThe Producer/Consumer ProblemWhy Passive Objects are ComponentsGas Station Simulation ProblemIdentifiers, Variables, Objects, and Collection ClassesIdentifiers and VariablesJava Identifiers and VariablesPrimitivesObjectsCollection Classes in JavaPROGRAM

  13. Superstitious responding and reinforcement rate under concurrent variable-interval extinction schedules.

    Science.gov (United States)

    Doughty, A H.; Shahan, T A.; Lattal, K A.

    2001-04-26

    To examine superstitious responding, four pigeons key pecked under multiple concurrent variable-interval 45 s variable-interval 90 s concurrent variable-interval 90 s variable-interval 180 s schedules in the absence of a changeover delay. The two variable-interval 90 s schedules then were replaced by extinction, and key-peck responding during extinction was examined as a function of the prevailing reinforcement rate. During the first several sessions, extinction-key responding was maintained closer to baseline levels in the presence of the higher reinforcement rate, and this effect dissipated or even reversed with continued exposure to extinction. Although extinction-key responding generally decreased to near-zero levels after several sessions, in a few instances, it continued for 30 and 45 sessions. These results demonstrate how concurrent variable-interval extinction schedules can be used to investigate what often has been labeled superstitious responding.

  14. Self-controlled concurrent feedback and the education of attention towards perceptual invariants.

    Science.gov (United States)

    Huet, Michaël; Camachon, Cyril; Fernandez, Laure; Jacobs, David M; Montagne, Gilles

    2009-08-01

    The present study investigates the effects of different types of concurrent feedback on the acquisition of perceptual-motor skills. Twenty participants walked through virtual corridors in which rhythmically opening and closing sliding doors were placed. The participants aimed to adjust their walking speed so as to cross the doors when the doors were close to their maximal aperture width. The highest level of performance was achieved by learners who practiced the task with unambiguous self-controlled concurrent feedback, which is to say, by learners who could request that feedback at wish. Practice with imposed rather than self-controlled feedback and practice without concurrent feedback were shown to be less effective. Finally, the way in which the self-controlled concurrent feedback was presented was also found to be of paramount importance; if the feedback is ambiguous, it may even prevent participants from learning the task. Clearly, unambiguous self-controlled feedback can give rise to higher levels of performance than other feedback conditions (compared to imposed schedule) but, depending on the way it is presented, the feedback can also prevent the participants from learning the task. In the discussion it is argued that unambiguous self-controlled concurrent feedback allows learners to more rapidly educate their attention towards more useful perceptual invariants and to calibrate the relation between perceptual invariants and action parameters.

  15. Concurrent conditional clustering of multiple networks: COCONETS.

    Directory of Open Access Journals (Sweden)

    Sabrina Kleessen

    Full Text Available The accumulation of high-throughput data from different experiments has facilitated the extraction of condition-specific networks over the same set of biological entities. Comparing and contrasting of such multiple biological networks is in the center of differential network biology, aiming at determining general and condition-specific responses captured in the network structure (i.e., included associations between the network components. We provide a novel way for comparison of multiple networks based on determining network clustering (i.e., partition into communities which is optimal across the set of networks with respect to a given cluster quality measure. To this end, we formulate the optimization-based problem of concurrent conditional clustering of multiple networks, termed COCONETS, based on the modularity. The solution to this problem is a clustering which depends on all considered networks and pinpoints their preserved substructures. We present theoretical results for special classes of networks to demonstrate the implications of conditionality captured by the COCONETS formulation. As the problem can be shown to be intractable, we extend an existing efficient greedy heuristic and applied it to determine concurrent conditional clusters on coexpression networks extracted from publically available time-resolved transcriptomics data of Escherichia coli under five stresses as well as on metabolite correlation networks from metabolomics data set from Arabidopsis thaliana exposed to eight environmental conditions. We demonstrate that the investigation of the differences between the clustering based on all networks with that obtained from a subset of networks can be used to quantify the specificity of biological responses. While a comparison of the Escherichia coli coexpression networks based on seminal properties does not pinpoint biologically relevant differences, the common network substructures extracted by COCONETS are supported by

  16. Aortopulmonary ectopic parathyroid gland and concurrent thymolipoma.

    Science.gov (United States)

    Abu Abeeleh, Mahmoud; Bani Hani, Amjad; Ghaith, Ata; Alodwan, Tareq; Bani Ismail, Zuhair; Alshehabat, Musa

    2016-10-01

    Ectopic parathyroid adenomas are considered the main cause of primary hyperparathyroidism. However, concurrent parathyroid and thymic pathologies are rarely diagnosed in the same patient. A 47-year-old man with history of diabetes mellitus, hypertension, and myasthenia gravis presented with persistent hypercalcemia. Laboratory investigations, computed tomography, and technetium-99 m sestamibi scintigraphy revealed ectopic parathyroid glands, a mediastinal mass, and an enlarged thymus. The patient underwent thymectomy and mass excision via a median sternotomy. Histopathology was consistent with ectopic parathyroid adenoma and thymolipoma. The serum calcium and parathormone concentrations normalized within 48 hours after surgery. © The Author(s) 2016.

  17. Concurrent Kimura disease and lupus nephritis

    Science.gov (United States)

    Wang, Haitao; Fang, Fang; Sun, Ying; Wang, Songlan; Mao, Yonghui

    2016-01-01

    Abstract Background: Kimura disease is a rare chronic inflammatory disorder with peripheral eosinophilia and elevated serum IgE and is also frequently complicated by nephropathy. Methods: We report a rare case of Kimura disease concomitant with lupus nephritis in a 72-year old male patient with recurrent unexplained lymphadenopathy, renal lesions, and immunologic abnormalities. Results: The patient was successfully managed with gamma immunoglobulin, intravenous pulse methylprednisolone therapy, hydroxychloroquine, and prednisone. Conclusion: This is the first report of a case of Kimura disease concomitant with lupus nephritis and highlights the importance of considering lupus nephritis as a possible concurrent disease in patients with Kimura disease that have immunologic abnormalities. PMID:27741124

  18. Concurrency control in distributed database systems

    CERN Document Server

    Cellary, W; Gelenbe, E

    1989-01-01

    Distributed Database Systems (DDBS) may be defined as integrated database systems composed of autonomous local databases, geographically distributed and interconnected by a computer network.The purpose of this monograph is to present DDBS concurrency control algorithms and their related performance issues. The most recent results have been taken into consideration. A detailed analysis and selection of these results has been made so as to include those which will promote applications and progress in the field. The application of the methods and algorithms presented is not limited to DDBSs but a

  19. Proceedings 8th Interaction and Concurrency Experience

    DEFF Research Database (Denmark)

    2015-01-01

    This volume contains the proceedings of ICE 2015, the 8th Interaction and Concurrency Experience, which was held in Grenoble, France on the 4th and 5th of June 2015 as a satellite event of DisCoTec 2015. The ICE procedure for paper selection allows PC members to interact, anonymously, with authors......, and altogether 9 papers, including 1 short paper, were accepted for publication (the workshop also featured 4 brief announcements which are not part of this volume). We were proud to host three invited talks, by Leslie Lamport (shared with the FRIDA workshop), Joseph Sifakis and Steve Ross-Talbot. The abstracts...

  20. Reliability-based concurrent subspace optimization method

    Institute of Scientific and Technical Information of China (English)

    FAN Hui; LI Wei-ji

    2008-01-01

    To avoid the high computational cost and much modification in the process of applying traditional re-liability-based design optimization method, a new reliability-based concurrent subspace optimization approach is proposed based on the comparison and analysis of the existing muhidisciplinary optimization techniques and reli-ability assessment methods. It is shown through a canard configuration optimization for a three-surface transport that the proposed method is computationally efficient and practical with the least modification to the current de-terministic optimization process.

  1. Concurrency-based approaches to parallel programming

    Science.gov (United States)

    Kale, L.V.; Chrisochoides, N.; Kohl, J.; Yelick, K.

    1995-01-01

    The inevitable transition to parallel programming can be facilitated by appropriate tools, including languages and libraries. After describing the needs of applications developers, this paper presents three specific approaches aimed at development of efficient and reusable parallel software for irregular and dynamic-structured problems. A salient feature of all three approaches in their exploitation of concurrency within a processor. Benefits of individual approaches such as these can be leveraged by an interoperability environment which permits modules written using different approaches to co-exist in single applications.

  2. Relaxed Operational Semantics of Concurrent Programming Languages

    Directory of Open Access Journals (Sweden)

    Gustavo Petri

    2012-08-01

    Full Text Available We propose a novel, operational framework to formally describe the semantics of concurrent programs running within the context of a relaxed memory model. Our framework features a "temporary store" where the memory operations issued by the threads are recorded, in program order. A memory model then specifies the conditions under which a pending operation from this sequence is allowed to be globally performed, possibly out of order. The memory model also involves a "write grain," accounting for architectures where a thread may read a write that is not yet globally visible. Our formal model is supported by a software simulator, allowing us to run litmus tests in our semantics.

  3. The Family of Concurrent Logic Programming Languages

    Science.gov (United States)

    1989-05-01

    193]. - 85 - 19.3 Proces to proceso mapping The question of how to map processes to processors is not unique to concurrent logic programming, and any...procinors(N,ToQ) queue(ToQ), -8 7 - procemorie(N,ToQ)Qnext. processors’(0,_). procesos (N,ToQ) - N>O I N’:=N-1, procesior(ToQ), processor’(N’ ,ToQ)Onext...of Computing, Imperial College, London, 1988. [35] Davison, A., POOL: A PARLOG object oriented language, Department of Computing, Im- penal College

  4. GLobal Integrated Design Environment (GLIDE): A Concurrent Engineering Application

    Science.gov (United States)

    McGuire, Melissa L.; Kunkel, Matthew R.; Smith, David A.

    2010-01-01

    The GLobal Integrated Design Environment (GLIDE) is a client-server software application purpose-built to mitigate issues associated with real time data sharing in concurrent engineering environments and to facilitate discipline-to-discipline interaction between multiple engineers and researchers. GLIDE is implemented in multiple programming languages utilizing standardized web protocols to enable secure parameter data sharing between engineers and researchers across the Internet in closed and/or widely distributed working environments. A well defined, HyperText Transfer Protocol (HTTP) based Application Programming Interface (API) to the GLIDE client/server environment enables users to interact with GLIDE, and each other, within common and familiar tools. One such common tool, Microsoft Excel (Microsoft Corporation), paired with its add-in API for GLIDE, is discussed in this paper. The top-level examples given demonstrate how this interface improves the efficiency of the design process of a concurrent engineering study while reducing potential errors associated with manually sharing information between study participants.

  5. Artificial concurrent catalytic processes involving enzymes.

    Science.gov (United States)

    Köhler, Valentin; Turner, Nicholas J

    2015-01-11

    The concurrent operation of multiple catalysts can lead to enhanced reaction features including (i) simultaneous linear multi-step transformations in a single reaction flask (ii) the control of intermediate equilibria (iii) stereoconvergent transformations (iv) rapid processing of labile reaction products. Enzymes occupy a prominent position for the development of such processes, due to their high potential compatibility with other biocatalysts. Genes for different enzymes can be co-expressed to reconstruct natural or construct artificial pathways and applied in the form of engineered whole cell biocatalysts to carry out complex transformations or, alternatively, the enzymes can be combined in vitro after isolation. Moreover, enzyme variants provide a wider substrate scope for a given reaction and often display altered selectivities and specificities. Man-made transition metal catalysts and engineered or artificial metalloenzymes also widen the range of reactivities and catalysed reactions that are potentially employable. Cascades for simultaneous cofactor or co-substrate regeneration or co-product removal are now firmly established. Many applications of more ambitious concurrent cascade catalysis are only just beginning to appear in the literature. The current review presents some of the most recent examples, with an emphasis on the combination of transition metal with enzymatic catalysis and aims to encourage researchers to contribute to this emerging field.

  6. Concurrent Initialization for Bearing-Only SLAM

    Directory of Open Access Journals (Sweden)

    Antoni Grau

    2010-03-01

    Full Text Available Simultaneous Localization and Mapping (SLAM is perhaps the most fundamental problem to solve in robotics in order to build truly autonomous mobile robots. The sensors have a large impact on the algorithm used for SLAM. Early SLAM approaches focused on the use of range sensors as sonar rings or lasers. However, cameras have become more and more used, because they yield a lot of information and are well adapted for embedded systems: they are light, cheap and power saving. Unlike range sensors which provide range and angular information, a camera is a projective sensor which measures the bearing of images features. Therefore depth information (range cannot be obtained in a single step. This fact has propitiated the emergence of a new family of SLAM algorithms: the Bearing-Only SLAM methods, which mainly rely in especial techniques for features system-initialization in order to enable the use of bearing sensors (as cameras in SLAM systems. In this work a novel and robust method, called Concurrent Initialization, is presented which is inspired by having the complementary advantages of the Undelayed and Delayed methods that represent the most common approaches for addressing the problem. The key is to use concurrently two kinds of feature representations for both undelayed and delayed stages of the estimation. The simulations results show that the proposed method surpasses the performance of previous schemes.

  7. Concurrent initialization for Bearing-Only SLAM.

    Science.gov (United States)

    Munguía, Rodrigo; Grau, Antoni

    2010-01-01

    Simultaneous Localization and Mapping (SLAM) is perhaps the most fundamental problem to solve in robotics in order to build truly autonomous mobile robots. The sensors have a large impact on the algorithm used for SLAM. Early SLAM approaches focused on the use of range sensors as sonar rings or lasers. However, cameras have become more and more used, because they yield a lot of information and are well adapted for embedded systems: they are light, cheap and power saving. Unlike range sensors which provide range and angular information, a camera is a projective sensor which measures the bearing of images features. Therefore depth information (range) cannot be obtained in a single step. This fact has propitiated the emergence of a new family of SLAM algorithms: the Bearing-Only SLAM methods, which mainly rely in especial techniques for features system-initialization in order to enable the use of bearing sensors (as cameras) in SLAM systems. In this work a novel and robust method, called Concurrent Initialization, is presented which is inspired by having the complementary advantages of the Undelayed and Delayed methods that represent the most common approaches for addressing the problem. The key is to use concurrently two kinds of feature representations for both undelayed and delayed stages of the estimation. The simulations results show that the proposed method surpasses the performance of previous schemes.

  8. Concurrent bilateral ectopic pregnancy: a rarity

    Directory of Open Access Journals (Sweden)

    Prabhleen Kaur

    2015-08-01

    Full Text Available Bilateral ectopic pregnancy is a rare twin gestation with only a few cases reported in the literature. We report a 30 year old woman without any high risk factor for ectopic pregnancy, who had concurrent bilateral ectopic pregnancy. A 30 year old female presented to the Gynecology emergency department complaining of vaginal bleeding and abdominal pain. The presumptive diagnosis of ruptured left sided ectopic pregnancy was made on basis of clinical findings and ultrasound finings. An emergency laparotomy was done revealed a hemoperitoneum of 1.5 liters, a ruptured left tubal pregnancy with active bleeding and right tubal un-ruptured ectopic was found. A bilateral salpingectomy was performed. Histopathology confirmed presence of chorionic villi in both tubes. In theory, laparoscopic salpingostomy is the best surgical approach in bilateral tubal pregnancy. However, bilateral salpingectomy may be necessary when both tubes are extensively damaged or are actively bleeding. Successful pregnancies have been reported after conservative surgical treatment of bilateral ectopic, but the risk of recurrence is high. Our decision for an emergency laparotomy followed by bilateral salpingectomy was based on the fact that the patient presented with acute abdomen and was haemodynamically unstable and there was extensive bilateral tubal damage. As the incidence of ectopic pregnancies is increasing concurrently with the incidences of pelvic inflammatory disease and use of assisted fertility techniques; it may be that these and ldquo;rare ectopics and rdquo; will become less uncommon. [Int J Reprod Contracept Obstet Gynecol 2015; 4(4.000: 1197-1199

  9. 农村土地产权抵押融资的联立选择行为及其影响因素分析--基于不同兼业程度农户的调查%An Analysis on Simultaneity Adoption of Rural Land Property Mortgage Financing and Its Influencing Factors-A Survey Based on Farmers with Different Levels of Concurrent-business

    Institute of Scientific and Technical Information of China (English)

    黎毅; 罗剑朝; 曹瓅; 房启明

    2015-01-01

    Based on the survey data of 501 farmers in Pingluo county of Ningxia Hui Autonomous Region,this pa⁃per employs the Bivariate Probit Model to make an analysis on the simultaneity adoption of land mortgate of farm⁃ers with different levels of concurrent-business and financial institutions and its supply and demand factors. The re⁃sults show that,although there is a high credit demand in the survey area,the successful rate of rural land mort⁃gage is lower because of the supply of credit control. Compared with the pure or one concurrent-business farmers, two concurrent-business farmers are more willing to do rural land mortgage and have a higher successful rate ac⁃cordingly. In the factors affecting rural land mortgage, some of them are common, but others are different. Among them, education level, rationality of the length of loan and cognition of mortgage are common decisive factors that affect the different farmers involved in land mortgage. Financial institutions play more attention to age, education level and credit records as well as other factors of different farmers when issuing land mortgage.%文章选取宁夏平罗501户农户实地调研数据,采用双变量Probit模型,对不同兼业程度农户和金融机构土地抵押联立选择行为及其供求因素进行分析,结果表明:当地普遍存在信贷需求,由于信贷供给抑制原因,农户土地抵押贷款可得性比例偏低。相较于纯农户和一兼农户,二兼农户土地贷款意愿可能性高,贷款可得性也更大;影响农户土地抵押既有共同因素也存在一定差异,其中农户教育程度、产品期限合理性和对抵押政策认知是影响不同农户参与土地抵押的共同决定性因素;金融机构土地抵押供给更多是考虑不同农户的年龄、教育程度和信用记录等变量。

  10. Concurrent Engineering Working Group White Paper Distributed Collaborative Design: The Next Step in Aerospace Concurrent Engineering

    Science.gov (United States)

    Hihn, Jairus; Chattopadhyay, Debarati; Karpati, Gabriel; McGuire, Melissa; Panek, John; Warfield, Keith; Borden, Chester

    2011-01-01

    As aerospace missions grow larger and more technically complex in the face of ever tighter budgets, it will become increasingly important to use concurrent engineering methods in the development of early conceptual designs because of their ability to facilitate rapid assessments and trades of performance, cost and schedule. To successfully accomplish these complex missions with limited funding, it is essential to effectively leverage the strengths of individuals and teams across government, industry, academia, and international agencies by increased cooperation between organizations. As a result, the existing concurrent engineering teams will need to increasingly engage in distributed collaborative concurrent design. The purpose of this white paper is to identify a near-term vision for the future of distributed collaborative concurrent engineering design for aerospace missions as well as discuss the challenges to achieving that vision. The white paper also documents the advantages of creating a working group to investigate how to engage the expertise of different teams in joint design sessions while enabling organizations to maintain their organizations competitive advantage.

  11. Analyzing and designing object-oriented missile simulations with concurrency

    Science.gov (United States)

    Randorf, Jeffrey Allen

    2000-11-01

    A software object model for the six degree-of-freedom missile modeling domain is presented. As a precursor, a domain analysis of the missile modeling domain was started, based on the Feature-Oriented Domain Analysis (FODA) technique described by the Software Engineering Institute (SEI). It was subsequently determined the FODA methodology is functionally equivalent to the Object Modeling Technique. The analysis used legacy software documentation and code from the ENDOSIM, KDEC, and TFrames 6-DOF modeling tools, including other technical literature. The SEI Object Connection Architecture (OCA) was the template for designing the object model. Three variants of the OCA were considered---a reference structure, a recursive structure, and a reference structure with augmentation for flight vehicle modeling. The reference OCA design option was chosen for maintaining simplicity while not compromising the expressive power of the OMT model. The missile architecture was then analyzed for potential areas of concurrent computing. It was shown how protected objects could be used for data passing between OCA object managers, allowing concurrent access without changing the OCA reference design intent or structure. The implementation language was the 1995 release of Ada. OCA software components were shown how to be expressed as Ada child packages. While acceleration of several low level and other high operations level are possible on proper hardware, there was a 33% degradation of 4th order Runge-Kutta integrator performance of two simultaneous ordinary differential equations using Ada tasking on a single processor machine. The Defense Department's High Level Architecture was introduced and explained in context with the OCA. It was shown the HLA and OCA were not mutually exclusive architectures, but complimentary. HLA was shown as an interoperability solution, with the OCA as an architectural vehicle for software reuse. Further directions for implementing a 6-DOF missile modeling

  12. 血清VEGF水平对中晚期宫颈癌诊断价值及同期放化疗疗效影响研究%Diagnostic value of serum VEGF level for advanced cervical cancer and its relationship with therapeutic efficacy of concurrent chemoradiotherapy

    Institute of Scientific and Technical Information of China (English)

    杨杰; 张泽高; 阿依古丽·依不拉音木; 热伊拉·麦买提伊敏; 王宁; 开丽曼·阿不都巴热; 哈斯也提·外里

    2013-01-01

    目的 探讨血清血管内皮生长因子(VEGF)水平对宫颈癌诊断价值及其同期放化疗预后影响.方法 选择经病理证实的中晚期宫颈鳞状细胞癌80例、慢性宫颈炎20例、体检健康人20例作为研究对象.酶联免疫吸附分析法测定研究对象血清VEGF基线水平,以及宫颈癌患者同期放化疗后3个月VEGF水平,分析其与临床疗效关系.结果 基线水平宫颈癌患者血清VEGF水平为237.36 μg/L,明显高于慢性宫颈炎和健康者(142.36μg/L,t=4.03,P=0.000).血清VEGF水平与肿瘤临床分期、分化程度及淋巴结转移密切相关,VEGF诊断宫颈癌的最佳界质为>197.52 μg/L,敏感性为0.88,特异性为0.72.VEGF在同期放化疗前后变化与疗效关系密切,完全缓解者变化明显大于进展者,VEGF基线高水平者进展或死亡明显高于低水平者.结论 血清VEGF水平对宫颈癌诊断价值不高,与宫颈癌分期、分级及淋巴转移密切相关,对宫颈癌同期放化疗预后具有一定预测价值.%Objective To investigate the diagnostic value of serum vascular endothelial growth factor (VEGF) level for cervical cancer and its relationship with the therapeutic efficacy of concurrent chemoradiotherapy (CCRT).Methods Eighty patients with a pathologically confirmed diagnosis of advanced cervical squamous cell carcinoma (CSCC),20 patients with chronic cervicitis,and 20 healthy persons (as controls) were enrolled in the study.The CSCC patients received CCRT.All the subjects had their baseline serum VEGF levels measured by enzyme-linked immunosorbent assay (ELISA);also,the CSCC patients had their serum VEGF levels measured by ELISA at 3 months after CCRT.The relationship between the serum VEGF levels and therapeutic efficacy of CCRT was analyzed.Results The CSCC patients had a significantly higher baseline serum VEGF level than the chronic cervicitis patients and controls (237.36 μg/L vs.142.36 μg/L,t =4.03,P =0.000).The serum VEGF level was closely

  13. In vitro dissolution of generic immediate-release solid oral dosage forms containing BCS class I drugs: comparative assessment of metronidazole, zidovudine, and amoxicillin versus relevant comparator pharmaceutical products in South Africa and India.

    Science.gov (United States)

    Reddy, Nallagundla H S; Patnala, Srinivas; Löbenberg, Raimar; Kanfer, Isadore

    2014-10-01

    Biowaivers are recommended for immediate-release solid oral dosage forms using dissolution testing as a surrogate for in vivo bioequivalence studies. Several guidance are currently available (the World Health Organization (WHO), the US FDA, and the EMEA) where the conditions are described. In this study, definitions, criteria, and methodologies according to the WHO have been applied. The dissolution performances of immediate-release metronidazole, zidovudine, and amoxicillin products purchased in South African and Indian markets were compared to the relevant comparator pharmaceutical product (CPP)/reference product. The dissolution performances were studied using US Pharmacopeia (USP) apparatus 2 (paddle) set at 75 rpm in each of three dissolution media (pH1.2, 4.5, and 6.8). Concentrations of metronidazole, zidovudine, and amoxicillin in each dissolution media were determined by HPLC. Of the 11 metronidazole products tested, only 8 could be considered as very rapidly dissolving products as defined by the WHO, whereas 2 of those products could be considered as rapidly dissolving products but did not comply with the f 2 acceptance criteria in pH 6.8. All 11 zidovudine products were very rapidly dissolving, whereas in the case of the 14 amoxicillin products tested, none of those products met any of the WHO criteria. This study indicates that not all generic products containing the same biopharmaceutics classification system (BCS) I drug and in similar strength and dosage form are necessarily in vitro equivalent. Hence, there is a need for ongoing market surveillance to determine whether marketed generic products containing BCS I drugs meet the release requirements to confirm their in vitro bioequivalence to the respective reference product.

  14. Data concurrency is required for estimating urban heat island intensity.

    Science.gov (United States)

    Zhao, Shuqing; Zhou, Decheng; Liu, Shuguang

    2016-01-01

    Urban heat island (UHI) can generate profound impacts on socioeconomics, human life, and the environment. Most previous studies have estimated UHI intensity using outdated urban extent maps to define urban and its surrounding areas, and the impacts of urban boundary expansion have never been quantified. Here, we assess the possible biases in UHI intensity estimates induced by outdated urban boundary maps using MODIS Land surface temperature (LST) data from 2009 to 2011 for China's 32 major cities, in combination with the urban boundaries generated from urban extent maps of the years 2000, 2005 and 2010. Our results suggest that it is critical to use concurrent urban extent and LST maps to estimate UHI at the city and national levels. Specific definition of UHI matters for the direction and magnitude of potential biases in estimating UHI intensity using outdated urban extent maps.

  15. Multidimensional self-esteem and alcohol use among Mexican American and White non-Latino adolescents: concurrent and prospective effects.

    Science.gov (United States)

    Swaim, Randall C; Wayman, Jeffrey C

    2004-10-01

    Self-esteem was evaluated among Mexican American and White non-Latino adolescents. Three dimensions of self-esteem-(a) self-confidence, (b) competence, and (c) social acceptance-were assessed for concurrent and longitudinal relationships to alcohol use. Various concurrent relationships were found between dimensions of self-esteem and alcohol use. Only 1 prospective effect was found, among Mexican American female adolescents, indicating that prior poor self-confidence predicts higher levels of alcohol use.

  16. Correlation between Trichomonas vaginalis and Concurrency: An Ecological Study.

    Science.gov (United States)

    Kenyon, Chris R; Hamilton, Deven T

    2016-01-01

    Objective. There is a large variation in the prevalence of Trichomonas vaginalis (TV) between different countries and between racial groups within countries. Sexual partner concurrency may play a role. We investigate the correlation between the prevalence of sexual partner concurrency and TV prevalence. Methods. Spearman's correlation to assess relationship between TV prevalence in women and point prevalence of concurrency in men in (1) 11 countries with comparable data (concurrency data from WHO Survey and TV prevalence data from Global Burden of Disease estimates) and (2) three racial groups in the United States (Add Health Study). Results. The prevalence of TV and concurrency was positively correlated in the international (rho = 0.84, P = 0.001) and USA study (rho = 1.0, P < 0.001). Conclusion. Prospective longitudinal studies that include measures of partner behavior are required to definitively establish the role of concurrency in the spread of TV.

  17. Coital frequency and condom use in monogamous and concurrent sexual relationships in Cape Town, South Africa

    Directory of Open Access Journals (Sweden)

    Wim Delva

    2013-04-01

    Full Text Available Introduction: A decreased frequency of unprotected sex during episodes of concurrent relationships may dramatically reduce the role of concurrency in accelerating the spread of HIV. Such a decrease could be the result of coital dilution – the reduction in per-partner coital frequency from additional partners – and/or increased condom use during concurrency. To study the effect of concurrency on the frequency of unprotected sex, we examined sexual behaviour data from three communities with high HIV prevalence around Cape Town, South Africa. Methods: We conducted a cross-sectional survey from June 2011 to February 2012 using audio computer-assisted self-interviewing to reconstruct one-year sexual histories, with a focus on coital frequency and condom use. Participants were randomly sampled from a previous TB and HIV prevalence survey. Mixed effects logistic and Poisson regression models were fitted to data from 527 sexually active adults reporting on 1210 relationship episodes to evaluate the effect of concurrency status on consistent condom use and coital frequency. Results: The median of the per-partner weekly average coital frequency was 2 (IQR: 1–3, and consistent condom use was reported for 36% of the relationship episodes. Neither per-partner coital frequency nor consistent condom use changed significantly during episodes of concurrency (aIRR=1.05; 95% confidence interval (CI: 0.99–1.24 and aOR=1.01; 95% CI: 0.38–2.68, respectively. Being male, coloured, having a tertiary education, and having a relationship between 2 weeks and 9 months were associated with higher coital frequencies. Being coloured, and having a relationship lasting for more than 9 months, was associated with inconsistent condom use. Conclusions: We found no evidence for coital dilution or for increased condom use during concurrent relationship episodes in three communities around Cape Town with high HIV prevalence. Given the low levels of self-reported consistent

  18. Concurrent Imitation Dynamics in Congestion Games

    CERN Document Server

    Ackermann, Heiner; Fischer, Simon; Hoefer, Martin

    2008-01-01

    Imitating successful behavior is a natural and frequently applied approach to trust in when facing scenarios for which we have little or no experience upon which we can base our decision. In this paper, we consider such behavior in atomic congestion games. We propose to study concurrent imitation dynamics that emerge when each player samples another player and possibly imitates this agents' strategy if the anticipated latency gain is sufficiently large. Our main focus is on convergence properties. Using a potential function argument, we how that our dynamics converge in a monotonic fashion to stable states. In such a state none of the players can improve its latency by imitating somebody else. As our main result, we show rapid convergence to approximate equilibria. At an approximate equilibrium only a small fraction of agents sustains a latency significantly above or below average. In particular, imitation dynamics behave like fully polynomial time approximation schemes (FPTAS). Fixing all other parameters, t...

  19. Certifying Concurrent Programs Using Transactional Memory

    Institute of Scientific and Technical Information of China (English)

    Long Li; Yu Zhang; Yi-Yun Chen; Yong Li

    2009-01-01

    Transactional memory (TM) is a new promising concurrency-control mechanism that can avoid many of the pitfalls of the traditional lock-based techniques. TM systems handle data races between threads automatically so that programmers do not have to reason about the interaction of threads manually. TM provides a programming model that may make the development of multi-threaded programs easier. Much work has been done to explore the various implementation strategies of TM systems and to achieve better performance, but little has been done on how to formally reason about programs using TM and how to make sure that such reasoning is sound. In this paper, we focus on the semantics of transactional memory and present a proof-carrying code (PCC) system for reasoning about programs using TM . We formalize our reasoning with respect to the TM semantics, prove its soundness, and use examples to demonstrate its effectiveness.

  20. Concurrent remote entanglement with continuous variables

    Science.gov (United States)

    Zalys-Geller, E.; Narla, A.; Shankar, S.; Hatridge, M.; Silveri, M.; Sliwa, K. M.; Mundhada, S. O.; Girvin, S. M.; Devoret, M. H.

    A necessary ingredient for large scale quantum information processing is the ability to entangle distant qubits on demand. In the field of superconducting quantum information, this process can be achieved by entangling stationary superconducting qubits with flying coherent states of microwave light, which are then co-amplified by a Josephson Parametric Converter (JPC). The JPC also serves as a which-path information eraser, causing the probabilistic continuous measurement process to concurrently entangle the qubits. We discuss the sensitivity of the experiment to the loss of quantum information during the flight of the coherent states, as well as strategies to improve which-path information erasure and reduce information loss to the degree required for entanglement generation. Work supported by ARO, AFOSR, NSF, and YINQE.

  1. Concurrent hypokalemic periodic paralysis and bipolar disorder

    Directory of Open Access Journals (Sweden)

    Chia-Lin Lin

    2015-01-01

    Full Text Available Primary periodic paralysis is a rare autosomal dominant disorder of ion-channel dysfunction, manifested by episodic flaccid paresis secondary to abnormal sarcolemma excitability. Membrane destabilization involving Na, K-ATPase has been hypothesized to be a biological etiology of the bipolar disorder (BD and the mechanisms underlying lithium therapy have been linked to it. To date, there has been only one reported case of BD comorbid with periodic paralysis. Herein, we reported another case of concurrent bipolar mania and hypokalemic periodic paralysis (HPP, one special form of periodic paralysis. Consistent with the previous case, our patient responded well to lithium treatment for both bipolar mania and HPP. This might provide some support to the hypothesis that the therapeutic effects of lithium in both BD and HPP could be due to the correction of the underlying common pathophysiology.

  2. Mining Concurrent Topical Activity in Microblog Streams

    CERN Document Server

    Panisson, A; Quaggiotto, M; Cattuto, C

    2014-01-01

    Streams of user-generated content in social media exhibit patterns of collective attention across diverse topics, with temporal structures determined both by exogenous factors and endogenous factors. Teasing apart different topics and resolving their individual, concurrent, activity timelines is a key challenge in extracting knowledge from microblog streams. Facing this challenge requires the use of methods that expose latent signals by using term correlations across posts and over time. Here we focus on content posted to Twitter during the London 2012 Olympics, for which a detailed schedule of events is independently available and can be used for reference. We mine the temporal structure of topical activity by using two methods based on non-negative matrix factorization. We show that for events in the Olympics schedule that can be semantically matched to Twitter topics, the extracted Twitter activity timeline closely matches the known timeline from the schedule. Our results show that, given appropriate techn...

  3. Avaliação farmacocinética de comprimidos contendo lamivudina e zidovudina em plasma humano Pharmacokinetic evaluation of lamivudine and zidovudine tablets in human plasma

    Directory of Open Access Journals (Sweden)

    João Eudes do Nascimento

    2004-03-01

    Full Text Available Este estudo se propõe a avaliar o perfil farmacocinético de comprimidos contendo lamivudina e zidovudina associados, produzidos pelo Laboratório Farmacêutico do Estado de Pernambuco - LAFEPE. O medicamento foi administrado em 10 voluntários sadios e foram observadas as concentrações plasmáticas dos dois anti-retrovirais durante 12 horas. A partir das concentrações plasmáticas foi possível encontrar os parâmetros farmacocinéticos de ambos os fármacos através de cálculos estatísticos. Os resultados obtidos foram comparados com aqueles resultantes de experimentos realizados por outros autores descritos neste trabalho, em que se verificou não haver diferenças significativas entre os valores encontrados e os descritos na literatura e que o fato dos anti-retrovirais estarem associados na mesma formulação não modificou o perfil cinético de nenhuma das substâncias.The purpose of this work was an evaluation of the pharmacokinetic profile from lamivudine and zidovudine combination tablets, produced by Laboratório Farmacêutico do Estado de Pernambuco - LAFEPE. The formulation was administered in 10 volunteers and the concentration-time serum profile was observed from both antiretroviral agents during 12 hours. From concentration-time serum profile the pharmacokinetic parameters for both drugs were calculated by statistical methods. The results were compared with those from experiments carried out by other authors referred in this paper. Differences between the results obtained herein and those from other authors were not significant. The kinetic profile for both substances was not modified by the anti-retroviral combination.

  4. Reverse transcriptase sequence of paired isolates of cerebrospinal fluid and blood from patients infected with human immunodeficiency virus type 1 during zidovudine treatment.

    Science.gov (United States)

    Di Stefano, M; Sabri, F; Leitner, T; Svennerholm, B; Hagberg, L; Norkrans, G; Chiodi, F

    1995-01-01

    Human immunodeficiency virus type 1 (HIV-1) isolates obtained from the blood of patients undergoing treatment with 3'-azido-3'-deoxythymidine (zidovudine [AZT]) show a decreased sensitivity to the drug in vitro. The aim of the present study was to determine if HIV-1 variants resistant to AZT are present also in the brain compartment. We selected sequential HIV-1 isolates from the blood and the cerebrospinal fluid (CSF) of six patients with HIV-1 infection undergoing AZT therapy for a time varying between 1 and 3 years. The isolates were used to infect peripheral blood mononuclear cell cultures which were used to prepare viral DNA. The viral DNA was amplified by PCR and then directly sequenced. Analysis of the reverse transcriptase (RT) sequence of the isolates from the CSF during therapy demonstrated that CSF-resistant isolates are characterized by the same mutations documented in resistant isolates from the blood compartment. Isolates obtained from one patient (patient 3) showed the same two mutations (codons 70 and 215) in blood and CSF, whereas isolates obtained from an additional four patients presented a different pattern of mutations in the two compartments. We also analyzed the degree of amino acid homology between RT sequences from blood and CSF isolates in patients before and during AZT treatment. The percentages of amino acid variations were approximately equal when isolates from the same or different compartments were considered. Excluding the codons involved in AZT resistance, the time point of sampling did not affect RT variations during therapy significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7536214

  5. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Joshy, K.S. [Department of Chemistry, CMS College Kottayam, Kerala (India); International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sharma, Chandra P. [Division of Biosurface Technology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Science and Technology, Poojappura, Thiruvananthapuram, Kerala (India); Kalarikkal, Nandakumar [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sandeep, K. [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Thomas, Sabu, E-mail: sabuchathukulam@yahoo.co.uk [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Pothen, Laly A. [Department of Chemistry, Bishop Moore College, Mavelikkara, Kerala (India)

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66 ± 12.22 nm and modified solid lipid nanoparticles showed an average size of 265.61 ± 80.44 nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. - Highlights: • SLN of AZT-SA, AZT-SA-AV was developed • Better drug loading efficacy • Good uptake.

  6. Risk adapted transmission prophylaxis to prevent vertical HIV–1 transmission: Effectiveness and safety of an abbreviated regimen of postnatal oral Zidovudine

    Directory of Open Access Journals (Sweden)

    Neubert Jennifer

    2013-01-01

    Full Text Available Abstract Background Antiretroviral drugs including zidovudine (ZDV are effective in reducing HIV mother to child transmission (MTCT, however safety concern remains. The optimal duration of postnatal ZDV has not been established in clinical studies and there is a lack of consensus regarding optimal management. The objective of this study was to investigate the effectiveness and safety of a risk adapted two week course of oral postnatal ZDV as part of a combined intervention to reduce MTCT. Methods 118 mother infant pairs were treated according to the German-Austrian recommendations for HIV therapy in pregnancy and in HIV exposed newborns between 2000–2010. In the absence of factors associated with an increased HIV–1 transmission risk, children were assigned to the low risk group and treated with an abbreviated postnatal regimen with oral ZDV for 2 weeks. In the presence of risk factors, postnatal ZDV was escalated accordingly. Results Of 118 mother-infant pairs 79 were stratified to the low risk group, 27 to the high risk group and 11 to the very high risk group for HIV–1 MTCT. 4 children were lost to follow up. Overall Transmission risk in the group regardless of risk factors and completion of prophylaxis was 1.8% (95% confidence interval (CI 0.09–6.6. If transmission prophylaxis was complete, transmission risk was 0.9% (95% CI 0.01-5.7. In the low risk group receiving two week oral ZDV transmission risk was 1.4% (95% CI 0.01–8.4 Conclusion These data demonstrate the effectiveness of a short neonatal ZDV regimen in infants of women on stable ART and effective HIV–1 suppression. Further evaluation is needed in larger studies.

  7. Side effects and tolerability of post-exposure prophylaxis with zidovudine, lamivudine, and lopinavir/ritonavir: a comparative study with HIV/AIDS patients

    Institute of Scientific and Technical Information of China (English)

    Cai Juan; Xiao Jiang; Zhang Qiang

    2014-01-01

    Background In the era of highly active antiretroviral therapy (HAART),the use of antiretrovirals as post-exposure prophylaxis (PEP) was the most important strategy for preventing occupational exposure to blood or fluids containing human immunodeficiency virus (HIV).The objective of this study was to retrospectively evaluate the tolerability,safety,and side effects of a HAART regimen containing three antiretroviral drugs,consisting of zidovudine,lamivudine,and lopinavir/ ritonavir,in healthcare personnel (HCP) who experienced occupational exposure to HIV.Methods The tolerability,safety,and side effects in 26 HCPs who experienced PEP and in 27 HIV/AIDS patients with HAART regimen,AZT+3TC+Lpv/r,were evaluated between January 2010 and December 2012.Results The most frequent clinical side effect was fatigue (in 23 cases,88.5%),and gastroenterological symptoms were the second most common side effects in HCP with PEP.Liver dysfunction was found in 10 cases (38.5%),while drug rash was found in 18 cases (69.2%) after PEP.The prevalence of side effects in HCPs who experienced PEP was higher than that in HIV/AIDS patients P <0.05.One nurse (3.8%) experienced severe gastrointestinal symptoms,which led to withdrawal of PEP.No HIV infection was found during 6-month follow-up period.Conclusion HCPs who received occupational PEP with triple-drug regimen,AZT+3TC+Lpv/r,experienced different side effects,and the tolerability and safety of PEP regimen were good in this cohort.

  8. Concurrent programming notations in the object-oriented language Arche

    OpenAIRE

    Benveniste, Marc; Issarny, Valérie

    1992-01-01

    Paradigms of object-oriented programming are attractive for the design of large distributed software. They notably provide a sound basis to develop applications that are easy to maintain and reuse. However, expressing concurrency in object-oriented languages raises some difficulties. For instance, integrating concurrency together with inheritance may lead to violate the encapsulation property of object-oriented programming. In this paper we present a new strongly-typed, concurrent object-orie...

  9. An Efficient Secure Real-Time Concurrency Control Protocol

    Institute of Scientific and Technical Information of China (English)

    XIAO Yingyuan; LIU Yunsheng; CHEN Xiangyang

    2006-01-01

    Secure real-time databases must simultaneously satisfy two requirements in guaranteeing data security and minimizing the missing deadlines ratio of transactions. However, these two requirements can conflict with each other and achieve one requirement is to sacrifice the other. This paper presents a secure real-time concurrency control protocol based on optimistic method. The concurrency control protocol incorporates security constraints in a real-time optimistic concurrency control protocol and makes a suitable tradeoff between security and real-time requirements by introducing secure influence factor and real-time influence factor. The experimental results show the concurrency control protocol achieves data security without degrading real-time performance significantly.

  10. Concurrence vectors for entanglement of high dimensional systems

    Institute of Scientific and Technical Information of China (English)

    You-quan LI; Guo-qiang ZHU

    2008-01-01

    The concurrence vectors are proposed by employing the fundamental representation of An Lie algebra,which provides a clear criterion to evaluate the entanglement of bipartite systems of arbitrary dimension.Accordingly,a state is separable if the norm of its concurrence vector vanishes.The state vectors related to SU(3)states and SO(3) states are discussed in detail.The sign situation of nonzero components of concurrence vectors of entangled bases presents a simple criterion to judge whether the whole Hilbert subspace spanned by those bases is entangled,or there exists an entanglement edge.This is illustrated in terms of the concurrence surfaces of several concrete examples.

  11. Is concurrency driving HIV transmission in sub-Saharan African sexual networks? The significance of sexual partnership typology.

    Science.gov (United States)

    Kretzschmar, Mirjam; Caraël, Michel

    2012-10-01

    Recently, there has been debate about the role of concurrent partnerships in driving the transmission of HIV, particularly in Southern Africa, where HIV prevalence is up to 25 % in many heterosexual populations and where evidence from sexual behavior surveys also suggests high levels of male concurrency. While mathematical modeling studies have shown that concurrency has the potential to enhance the speed at which HIV spreads in a population, empirical studies up to now have failed to provide conclusive evidence supportive of these effects. Here we discuss some reasons for the apparent discrepancy between theoretical and empirical studies. We propose that studying the impact of concurrency on HIV transmission should be differentiated by taking more insight from social and behavioral studies on sexual partnerships into account. We also suggest that a more rigorous definition is needed for when a factor is considered a driving force for HIV epidemic spread. We illustrate this with a modeling example.

  12. scriptJ(TM) extension of Java(R): discretionary concurrency for privacy-friendly, client-cloud computing

    CERN Document Server

    Hewitt, Carl

    2010-01-01

    scriptJ(TM) is a general purpose programming language for implementing massive local and nonlocal concurrency. It is differentiated from other concurrent languages by the following: - Universality o Everything in the language is accomplished using message passing including the very definition of scriptJ itself. o Directly express discretionary push and pull concurrency o Functional and Logic Programming are integrated into general concurrent programming. o Programs do not expose low-level implementation mechanisms such as threads, tasks, channels, queues, locks, cores, etc. o Program resource control of energy, processing, storage, and communications using sponsors. o Binary XML and JSON are data types o Applications cannot directly harm each other. - Efficiency o Allow execution to be dynamically adjusted for system load and capacity (cores) o Minimize latency along critical paths - For ease of reading, programming can be displayed using a 2-dimensional textual typography (as is often done in mathematics). s...

  13. Concurrency and climate change signal in Scottish flooding

    Science.gov (United States)

    Harding, A. E.; Butler, A.; Goody, N.; Bertram, D.; Baggaley, N.; Tett, S. F.

    2013-12-01

    The Scottish Environment Protection Agency maintains a database of river gauging stations and intensity rain-gauges with a 3-hourly resolution that covers the majority of Scotland. Both SEPA and a number of other Scottish agencies are invested in climate change attribution in this data set. SEPA's main interest lies in trend detection and changes in river level (';stage') data throughout Scotland. Emergency response teams are more concerned with the concurrency of multiple flood events that might stretch their ability to respond effectively. Unfortunately, much of the rainfall signal within SEPA's river-gauge data is altered by land use changes, modified by artificial interventions such as reservoirs, compromised by tidal flow, or obscured by measurement issues. Data reduction techniques, indices of extreme rainfall, and hydrology-driven discrimination have been employed to produce a reduced set of flood-relevant information for 24-hour ';flashy' events. Links between this set and North Atlantic circulation have been explored, as have patterns of mutual occurrence across Scotland and location- and seasonally- dependent trends through time. Both frontal systems and summer convective storms have been characterised in terms of subsequent flood-inducing flow regime, their changing behaviour over the last fifty years, and their spatial extent. This is the first stage of an ongoing project that will intelligently expand to take less robust river and rain-gauge stations into account through statistical analysis and hydrological modelling. It is also the first study of its type to analyse a nation-scale dataset of both rainfall and river flow from multiple catchments for flood event concurrency. As rainfall events are expected to intensify across much of Europe, this kind of research is likely to have an increasing degree of relevance for policy-makers. This project demonstrates that productive, policy-relevant and mutually-rewarding partnerships are already underway.

  14. Pain, Disability and Sleep Quality in Patients With Rotator Cuff Tendinopathy and Concurrent Myofascial Pain

    Directory of Open Access Journals (Sweden)

    Morteza Nakhaei Amroodi

    2016-05-01

    Full Text Available Background Rotator cuff tendinopathy and concurrent myofascial pain may result in sleep disturbances, poor quality of life, and social dysfunction along with chronic annoying pain and progressive physical disability. Objectives The present study aimed to assess severity of pain, physical disability, and sleep quality in patients with rotator cuff tendinopathy and concurrent myofascial pain. Patients and Methods This case-control study was conducted on 30 consecutive patients with rotator cuff tendinopathy without tear (impingement syndrome and concurrent myofascial pain referred to the shoulder clinic in Shafa-Yahyaian Hospital during year 2014 (January to April. Eighteen gender and age-matched healthy individuals without any history of rotator cuff tendinopathy were included as controls. Along with baseline assessment, for determining the level of arm, shoulder and hand disability, the quick disabilities of the arm, shoulder and hand questionnaire was also used. Sleep quality was assessed by the pittsburgh sleep quality index (PSQI. Results Compared to healthy individuals, the mean shoulder disability score was significantly higher in the patient group (P = 0.001. Also, regarding sleep quality, the mean score was significantly higher in the patient group when compared with healthy subjects (P = 0.002. Conclusions Patients with rotator cuff tendinopathy concurrent with myofascial pain experienced low level of sleep quality along with severe pain and physical disability. In order to improve clinical outcome of these patients, improving physical function and sleep quality in these patients is necessary.

  15. Known-Groups and Concurrent Validity of the Mandarin Tone Identification Test (MTIT.

    Directory of Open Access Journals (Sweden)

    Shufeng Zhu

    Full Text Available The Mandarin Tone Identification Test (MTIT is a new test designed to assess the tone identification abilities of children with hearing impairment (HI. Evidence for reliability and sensitivity has been reported. The present study aimed to evaluate the known-groups and concurrent validity of the MTIT.The MTIT and Mandarin Pediatric Speech Intelligibility test (MPSI were administered in quiet and in noise conditions. The known-groups validity was evaluated by comparing the performance of the MTIT on children with two different levels of HI. The MPSI was included to evaluate the concurrent validity of the MTIT.81 children with HI were recruited in the present study. They were Mandarin-speaking children with profound HI (mean age = 9; 0, n = 41 and with moderate to severe HI (mean age = 8; 9, n = 40.Scores on the MTIT differed between the two groups with different hearing levels suggesting good known-groups validity. A strong relationship between tone and sentence perception both in quiet and in noise provided preliminary evidence for concurrent validity.The present study confirmed that the MTIT has good known-groups validity and provided preliminary evidence for concurrent validity. The MTIT could be used to evaluate tone identification ability in children with HI with confidence.

  16. Verification of concurrent systems with VerCors

    NARCIS (Netherlands)

    Amighi, A.; Blom, Stefan; Darabi, Saeed; Huisman, Marieke; Mostowski, Wojciech; Zaharieva, M.; Bernardo, Marco; Damiani, Ferruccio; Hahnle, Reiner; Johnsen, Einar; Schaefer, Ina

    This paper presents the VerCors approach to verification of concurrent software. It first discusses why verification of concurrent software is important, but also challenging. Then it shows how within the VerCors project we use permission-based separation logic to reason about multithreaded Java

  17. 28 CFR 0.56 - Exclusive or concurrent jurisdiction.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exclusive or concurrent jurisdiction. 0.56 Section 0.56 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Criminal Division § 0.56 Exclusive or concurrent jurisdiction. The Assistant Attorney General...

  18. Graphical modelling language for spycifying concurrency based on CSP

    NARCIS (Netherlands)

    Hilderink, G.H.

    2003-01-01

    Introduced in this (shortened) paper is a graphical modelling language for specifying concurrency in software designs. The language notations are derived from CSP and the resulting designs form CSP diagrams. The notations reflect both data-flow and control-flow aspects of concurrent software

  19. Reasoning about Concurrent Actionsin Multi-Agent Systems

    Institute of Scientific and Technical Information of China (English)

    FAN Xiaocong; XU Dianxiang; HOU Jianmin; ZHENG Guoliang

    1999-01-01

    Concurrence is an important researcharea in collaborative problem solving.This paper offers a formaldefinition for cooperative sequences in multi-agentsystems, discussesthe different categories of concurrent actions, and proposes somerules forsituation revision and an algorithm used to generate resultingsituations.An example is also given to show how to solve concurrentproblems occurring inmulti-agent systems.

  20. Concurrent Lexicalized Dependency Parsing The ParseTalk Model

    CERN Document Server

    Broeker, N; Schacht, S; Broeker, Norbert; Hahn, Udo; Schacht, Susanne

    1994-01-01

    A grammar model for concurrent, object-oriented natural language parsing is introduced. Complete lexical distribution of grammatical knowledge is achieved building upon the head-oriented notions of valency and dependency, while inheritance mechanisms are used to capture lexical generalizations. The underlying concurrent computation model relies upon the actor paradigm. We consider message passing protocols for establishing dependency relations and ambiguity handling.

  1. Separate versus Concurrent Calibration Methods in Vertical Scaling.

    Science.gov (United States)

    Karkee, Thakur; Lewis, Daniel M.; Hoskens, Machteld; Yao, Lihua; Haug, Carolyn

    Two methods to establish a common scale across grades within a content area using a common item design (separate and concurrent) have previously been studied under simulated conditions. Separate estimation is accomplished through separate calibration and grade-by-grade chained linking. Concurrent calibration established the vertical scale in a…

  2. Dynamic Frames Based Verification Method for Concurrent Java Programs

    NARCIS (Netherlands)

    Mostowski, Wojciech

    2016-01-01

    In this paper we discuss a verification method for concurrent Java programs based on the concept of dynamic frames. We build on our earlier work that proposes a new, symbolic permission system for concurrent reasoning and we provide the following new contributions. First, we describe our approach

  3. Location and acoustic scale cues in concurrent speech recognition.

    Science.gov (United States)

    Ives, D Timothy; Vestergaard, Martin D; Kistler, Doris J; Patterson, Roy D

    2010-06-01

    Location and acoustic scale cues have both been shown to have an effect on the recognition of speech in multi-speaker environments. This study examines the interaction of these variables. Subjects were presented with concurrent triplets of syllables from a target voice and a distracting voice, and asked to recognize a specific target syllable. The task was made more or less difficult by changing (a) the location of the distracting speaker, (b) the scale difference between the two speakers, and/or (c) the relative level of the two speakers. Scale differences were produced by changing the vocal tract length and glottal pulse rate during syllable synthesis: 32 acoustic scale differences were used. Location cues were produced by convolving head-related transfer functions with the stimulus. The angle between the target speaker and the distracter was 0 degrees, 4 degrees, 8 degrees, 16 degrees, or 32 degrees on the 0 degrees horizontal plane. The relative level of the target to the distracter was 0 or -6 dB. The results show that location and scale difference interact, and the interaction is greatest when one of these cues is small. Increasing either the acoustic scale or the angle between target and distracter speakers quickly elevates performance to ceiling levels.

  4. A concurrent vector-based steering framework for particle transport

    Science.gov (United States)

    Apostolakis, John; Brun, René; Carminati, Federico; Gheata, Andrei; Wenzel, Sandro

    2014-06-01

    High Energy Physics has traditionally been a technology-limited science that has pushed the boundaries of both the detectors collecting the information about the particles and the computing infrastructure processing this information. However, since a few years the increase in computing power comes in the form of increased parallelism at all levels, and High Energy Physics has now to optimise its code to take advantage of the new architectures, including GPUs and hybrid systems. One of the primary targets for optimisation is the particle transport code used to simulate the detector response, as it is largely experiment independent and one of the most demanding applications in terms of CPU resources. The Geant Vector Prototype project aims to explore innovative designs in particle transport aimed at obtaining maximal performance on the new architectures. This paper describes the current status of the project and its future perspectives. In particular we describe how the present design tries to expose the parallelism of the problem at all possible levels, in a design that is aimed at minimising contentions and maximising concurrency, both at the coarse granularity level (threads) and at the micro granularity one (vectorisation, instruction pipelining, multiple instructions per cycle). The future plans and perspectives will also be mentioned.

  5. Concurrent Object-Oriented Programming Based on MPI

    Institute of Scientific and Technical Information of China (English)

    鲁宏伟; 汪厚祥; 裴晓黎; 肖永玲

    2004-01-01

    Object-oriented model possesses inherent concurrency. Integration of concurrency and object-orientation is a promising new field. MPI is a message-passing standard and has been adopted by more and more systems. This paper proposes a novel approach to realize concurrent object-oriented programming based on Message-passing interface(MPI) in which future method communication is adopted between concurrent objects. A state behavior set is proposed to solve inheritance anomaly, and a bounded buffer is taken as an example to illustrate this proposal. The definition of ParaMPI class, which is the most important class in the concurrent class library,and implementation issues are briefly described.

  6. Proceedings Fourth Interaction and Concurrency Experience

    CERN Document Server

    Silva, Alexandra; Bruni, Roberto; Carbone, Marco; 10.4204/EPTCS.59

    2011-01-01

    This volume contains the pre-proceedings of ICE'11, the 4th Interaction and Concurrency Experience workshop, which was held in Reykjavik, Iceland on the 9th of June 2011 as a satellite event of DisCoTec'11. The topic of ICE'11 was Reliable and Contract-based Interaction. Reliable interactions are, e.g., those enjoying suitable logical, behavioural, or security properties, or adhering to certain QoS standards. Contract-based interactions are, e.g., those where the interacting entities are committed to give certain guarantees whenever certain assumptions are met by their operating environment. The ICE procedure for paper selection allows for PC members to interact, anonymously, with authors. During the review phase, each submitted paper is published on a Wiki and associated with a discussion forum whose access is restricted to the authors and to all the PC members not declaring a conflict of interests. The PC members post comments and questions that the authors reply to. Each paper was reviewed by four PC membe...

  7. Creatine and Caffeine: Considerations for Concurrent Supplementation.

    Science.gov (United States)

    Trexler, Eric T; Smith-Ryan, Abbie E

    2015-12-01

    Nutritional supplementation is a common practice among athletes, with creatine and caffeine among the most commonly used ergogenic aids. Hundreds of studies have investigated the ergogenic potential of creatine supplementation, with consistent improvements in strength and power reported for exercise bouts of short duration (≤ 30 s) and high intensity. Caffeine has been shown to improve endurance exercise performance, but results are mixed in the context of strength and sprint performance. Further, there is conflicting evidence from studies comparing the ergogenic effects of coffee and caffeine anhydrous supplementation. Previous research has identified independent mechanisms by which creatine and caffeine may improve strength and sprint performance, leading to the formulation of multi-ingredient supplements containing both ingredients. Although scarce, research has suggested that caffeine ingestion may blunt the ergogenic effect of creatine. While a pharmacokinetic interaction is unlikely, authors have suggested that this effect may be explained by opposing effects on muscle relaxation time or gastrointestinal side effects from simultaneous consumption. The current review aims to evaluate the ergogenic potential of creatine and caffeine in the context of high-intensity exercise. Research directly comparing coffee and caffeine anhydrous is discussed, along with previous studies evaluating the concurrent supplementation of creatine and caffeine.

  8. A Secure Time-Stamp Based Concurrency Control Protocol For Distributed Databases

    Directory of Open Access Journals (Sweden)

    Shashi Bhushan

    2007-01-01

    Full Text Available In distributed database systems the global database is partitioned into a collection of local databases stored at different sites. In this era of growing technology and fast communication media, security has an important role to play. In this paper we presented a secure concurrency control protocol (SCCP based on the timestamp ordering, which provides concurrency control and maintains security. We also implemented SCCP and a comparison of SCCP is presented in three cases (High, Medium and Low security levels. In this experiment, It is observed that throughput of the system decreases as the security level of the transaction increases, i.e., there is tradeoff between the security level and the throughput of the system.

  9. Effect of concurrent use of anti-retroviral therapy and levonorgestrel sub-dermal implant for contraception on CD4 counts: a prospective cohort study in Kenya

    Directory of Open Access Journals (Sweden)

    David Hubacher

    2013-03-01

    Full Text Available Introduction: Simultaneous use of contraceptive hormones and anti-retroviral therapy (ART may theoretically lessen the effectiveness of both. Women on ART need assurance that hormonal contraception is safe and effective. The sub-dermal implant is an ideal product to study: low and steady progestin release and no adherence uncertainties. We sought to determine if the medications’ effectiveness is compromised. Methods: We conducted a prospective cohort study among women on first line ART (stavudine or zidovudine and lamivudine+nevirapine. We recruited new implant users and matched them to women not using hormonal contraception, based on age and baseline CD4. Participants were followed prospectively for up to two years, recording serial CD4 measures and medical histories. We used generalized growth curve models and Wald chi-square tests to compare changes in CD4 counts across study groups. Prospective CD4 measures were censored (excluded if any of the following events occurred: change in ART, implant removal or use of any hormonal contraception among controls. We examined incidence of opportunistic infection and pregnancy. Results: We matched 48 implant users to 33 non-hormonal controls. Over time, CD4 counts for both groups rose slightly but did not deviate significantly from each other (p=0.44. Opportunistic infection rates did not differ between the groups. None of the implant users and one of the non-hormonal controls became pregnant during follow-up. Conclusions: This small study found concurrent use of contraceptive implants and ART to be safe and effective. Although other hormonal contraceptive products and ART regimens may interact in unknown ways, the results of this study are reassuring.

  10. Anaemia and zidovudine-containing antiretroviral therapy in paediatric antiretroviral programmes in the IeDEA Paediatric West African Database to evaluate AIDS

    Directory of Open Access Journals (Sweden)

    Lorna A Renner

    2013-09-01

    Full Text Available Introduction: There is a risk of anaemia among HIV-infected children on antiretroviral therapy (ART containing zidovudine (ZDV recommended in first-line regimens in the WHO guidelines. We estimated the risk of severe anaemia after initiation of a ZDV-containing regimen in HIV-infected children included in the IeDEA West African database. Methods: Standardized collection of data from HIV-infected children (positive PCR<18 months or positive serology ≥18 months followed up in HIV programmes was included in the regional IeDEA West Africa collaboration. Ten clinical centres from seven countries contributed (Benin, Burkina Faso, Côte d'Ivoire, Gambia, Ghana, Mali and Senegal to this collection. Inclusion criteria were age <16 years and starting ART. We explored the data quality of haemoglobin documentation over time and the incidence and predictors of severe anaemia (Hb<7g/dL per 100 child-years of follow-up over the duration of first-line antiretroviral therapy. Results: As of December 2009, among the 2933 children included in the collaboration, 45% were girls, median age was five years; median CD4 cell percentage was 13%; median weight-for-age z-score was−2.7; and 1772 (60.4% had a first-line ZDV-containing regimen. At baseline, 70% of the children with a first-line ZDV-containing regimen had a haemoglobin measure available versus 76% in those not on ZDV (p≤0.01: the prevalence of severe anaemia was 3.0% (n=38 in the ZDV group versus 10.2% (n=89 in those without (p<0. 01. Over the first-line follow-up, 58.9% of the children had ≥1 measure of haemoglobin available in those exposed to ZDV versus 60.4% of those not (p=0.45. Severe anaemia occurred in 92 children with an incidence of 2.47 per 100 child-years of follow-up in those on a ZDV-containing regimen versus 4.25 in those not (p≤0.01. Adjusted for age at ART initiation and first-line regimen, a weight-for-age z-score ≤−3 was a strong predictor associated with a 5.59 times risk of

  11. Controlled Owicki-Gries Concurrency: Reasoning about the Preemptible eChronos Embedded Operating System

    Directory of Open Access Journals (Sweden)

    June Andronick

    2015-11-01

    Full Text Available We introduce a controlled concurrency framework, derived from the Owicki-Gries method, for describing a hardware interface in detail sufficient to support the modelling and verification of small, embedded operating systems (OS's whose run-time responsiveness is paramount. Such real-time systems run with interrupts mostly enabled, including during scheduling. That differs from many other successfully modelled and verified OS's that typically reduce the complexity of concurrency by running on uniprocessor platforms and by switching interrupts off as much as possible. Our framework builds on the traditional Owicki-Gries method, for its fine-grained concurrency is needed for high-performance system code. We adapt it to support explicit concurrency control, by providing a simple, faithful representation of the hardware interface that allows software to control the degree of interleaving between user code, OS code, interrupt handlers and a scheduler that controls context switching. We then apply this framework to model the interleaving behavior of the eChronos OS, a preemptible real-time OS for embedded micro-controllers. We discuss the accuracy and usability of our approach when instantiated to model the eChronos OS. Both our framework and the eChronos model are formalised in the Isabelle/HOL theorem prover, taking advantage of the high level of automation in modern reasoning tools.

  12. Biomonitoring of concurrent mycotoxin exposure among adults in Sweden through urinary multi-biomarker analysis.

    Science.gov (United States)

    Wallin, S; Gambacorta, L; Kotova, N; Lemming, E Warensjö; Nälsén, C; Solfrizzo, M; Olsen, M

    2015-09-01

    Mycotoxin producing moulds may contaminate numerous agricultural commodities either before harvest or during storage. A varied diet consisting of different foods may therefore be contaminated with a range of mycotoxins. The aim of the present study was to study concurrent exposure to mycotoxins through urinary multi-biomarker analysis, as well as its possible associations with the diet. Urinary samples from 252 adults, participating in the Swedish national dietary survey Riksmaten 2010-11, were collected together with a 4-day diet record. Concurrent mycotoxin exposure was studied using a multi-biomarker LC-MS/MS method. The results revealed that exposure to mycotoxins is common and concurrent exposure to more than one toxin was found in 69% of the study population. However, when comparing the number of toxins detected with the reported consumption data it was difficult to distinguish food patterns which would indicate an increased risk of exposure to many mycotoxins simultaneously. This is the first study to investigate concurrent mycotoxin exposure and urinary levels of fumonisin B1 (FB1), fumonisin B2 (FB2), nivalenol (NIV), ochratoxin A (OTA), zearalenone (ZEA), α-zearalenol (α-ZOL), β-zearalenol (β-ZOL) and de-epoxydeoxynivalenol (DOM-1) among adults in Sweden.

  13. Transactions on Petri Nets and Other Models of Concurrency VI

    DEFF Research Database (Denmark)

    The sixth volume of ToPNoC includes revised versions of selected papers from workshops and tutorials held at the 32nd International Conference on Application and Theory of Petri Nets and Concurrency. It also contains a special section on Networks, Protocols, and Services, as well as a contributed...... paper submitted through the regular submission track of ToPNoC. The 14 papers cover a diverse range of topics including model checking and system verification, synthesis, foundational work on specific classes of Petri nets, and innovative applications of Petri nets and other models of concurrency. Thus...... this volume gives a good view of ongoing concurrent systems and Petri nets research....

  14. Computational simulation of concurrent engineering for aerospace propulsion systems

    Science.gov (United States)

    Chamis, C. C.; Singhal, S. N.

    1992-01-01

    Results are summarized of an investigation to assess the infrastructure available and the technology readiness in order to develop computational simulation methods/software for concurrent engineering. These results demonstrate that development of computational simulations methods for concurrent engineering is timely. Extensive infrastructure, in terms of multi-discipline simulation, component-specific simulation, system simulators, fabrication process simulation, and simulation of uncertainties - fundamental in developing such methods, is available. An approach is recommended which can be used to develop computational simulation methods for concurrent engineering for propulsion systems and systems in general. Benefits and facets needing early attention in the development are outlined.

  15. Computational simulation for concurrent engineering of aerospace propulsion systems

    Science.gov (United States)

    Chamis, C. C.; Singhal, S. N.

    1993-01-01

    Results are summarized for an investigation to assess the infrastructure available and the technology readiness in order to develop computational simulation methods/software for concurrent engineering. These results demonstrate that development of computational simulation methods for concurrent engineering is timely. Extensive infrastructure, in terms of multi-discipline simulation, component-specific simulation, system simulators, fabrication process simulation, and simulation of uncertainties--fundamental to develop such methods, is available. An approach is recommended which can be used to develop computational simulation methods for concurrent engineering of propulsion systems and systems in general. Benefits and issues needing early attention in the development are outlined.

  16. Concurrent life-course trajectories of employment and marijuana-use: exploring interdependence of longitudinal outcomes.

    Science.gov (United States)

    Hara, Motoaki; Huang, David Y C; Weiss, Robert E; Hser, Yih-Ing

    2013-01-01

    This study analyzes data on 7661 individuals who participated in the 1979 National Longitudinal Survey of Youth (NLSY79) to estimate trajectories of employment and marijuana-use over a 17-year period. Bivariate random intercept and slope modeling is applied to examine concurrently the cross-correlation between the two concurrent longitudinal trajectories from age 23 to 39. Parameter estimates indicate baseline level (at age 23) of employment to be negatively correlated with marijuana, suggesting marijuana-use is associated with lower workforce productivity at age 23. The longitudinal employment slope is positively correlated with employment intercept for both males and females, indicating that survey participants with higher levels of employment at age 23 are more likely to have a positive impact on employment trajectory over time. For males, however, the employment slope is also significantly correlated with marijuana intercept (r=-0.07), indicating marijuana-use in early adulthood may uniquely lower workforce productivity over age.

  17. The lived experience of high school instructors teaching concurrent enrollment courses

    Science.gov (United States)

    Exby, Heather Dickinson

    This qualitative phenomenological study explored the lived experiences of high school instructors teaching concurrent enrollment courses. The phenomenon was examined using the Stevick-Colaizzi-Keen approach for phenomenological research as outlined by Moustakas through data collected in personal interviews with 10 high school instructors who taught concurrent enrollment college courses in their high schools. Instructional Quality, Passion, Commitment to Students, and Pride emerged as the four structural themes that framed the meaning of the phenomenon. Balance within a Liminal Space emerged as the essence of the phenomenon. Approved high school instructors approached their college concurrent enrollment responsibilities with honor and pride in teaching at the college level, as well as with duty to provide rigorous academic instruction that supported student development and transition and met the college instructional expectations. The phenomenon of teaching of college courses in a high school environment required teachers to balance the demands of their high school environment and instructional philosophies of secondary education with the curricular demands and differing instructional philosophies of higher education. This resulted in concurrent enrollment's unique instructional position in a liminal or threshold space between secondary and postsecondary education sectors. The liminal space of concurrent enrollment, although laden with ambiguity and tension, provided teachers with unique opportunities to facilitate the teaching of college academic curriculum integrated with time-built relationships with students and commitment to student learning to create positive, enhanced academic experiences for students. The "productive tension" of the liminal space can serve as a unique and optimal laboratory for addressing some of the pervasive problems with successful matriculation to college and strengthen the college transition process for greater student success.

  18. Concurrent spinal cord and vertebral bone marrow radionecrosis 8 years after therapeutic irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Warscotte, L.; Sindic, C.J.M. [Department of Neurology, Universite Catholique de Louvain (Belgium); Duprez, T.; Lecouvet, F.E. [Department of Radiology and Medical Imaging, Universite Catholique de Louvain, Brussels (Belgium); Lonneux, M. [Department of Nuclear Medicine, Universite Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels (Belgium); Michaux, L. [Department of Hematology, Universite Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels (Belgium); Renard, L. [Department of Radiation Oncology, Universite Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels (Belgium)

    2002-03-01

    Concurrent radionecrosis within the spinal cord and the bone marrow at the same thoracic level was observed 8 years after localized therapeutic irradiation in a patient who had undergone repeated cycles of radiotherapy, glucocorticoid treatment, and chemotherapy for a non-Hodgkin's lymphoma. Mechanisms combining radiotoxic potentialization by glucocorticoids/alkylating agents and delayed radiation-induced vasculitis involving the common arterial pathways to the spinal cord and to the vertebrae were speculated to have acted in a synergistic way. (orig.)

  19. Visualizing Concurrency Control Algorithms for Real-Time Database Systems

    Directory of Open Access Journals (Sweden)

    Olusegun Folorunso

    2008-11-01

    Full Text Available This paper describes an approach to visualizing concurrency control (CC algorithms for real-time database systems (RTDBs. This approach is based on the principle of software visualization, which has been applied in related fields. The Model-View-controller (MVC architecture is used to alleviate the black box syndrome associated with the study of algorithm behaviour for RTDBs Concurrency Controls. We propose a Visualization "exploratory" tool that assists the RTDBS designer in understanding the actual behaviour of the concurrency control algorithms of choice and also in evaluating the performance quality of the algorithm. We demonstrate the feasibility of our approach using an optimistic concurrency control model as our case study. The developed tool substantiates the earlier simulation-based performance studies by exposing spikes at some points when visualized dynamically that are not observed using usual static graphs. Eventually this tool helps solve the problem of contradictory assumptions of CC in RTDBs.

  20. A case for evaluating sensor network protocols concurrently

    KAUST Repository

    Gnawali, Omprakash

    2010-01-01

    Researchers typically evaluate and compare protocols on the testbeds by running them one at a time. This methodology ignores the variation in link qualities and wireless environment across these experiments. These variations can introduce significant noise in the results. Evaluating two protocols concurrently, however, suffers from inter-protocol interactions. These interactions can perturb performance even under very light load, especially timing and timing sensitive protocols. We argue that the benefits of running protocols concurrently greatly outweigh the disadvantages. Protocols rarely run in isolation in real networks, and so considering such interactions is valuable. Although the wireless environment is still uncontrolled, concurrent evaluations make comparisons fair and more statistically sound. Through experiments on two testbeds, we make the case for evaluating and comparing low data-rate sensor network protocols by running them concurrently. Copyright 2010 ACM.

  1. Human operant learning under concurrent reinforcement of response variability

    NARCIS (Netherlands)

    Maes, J.H.R.; Goot, M.H. van der

    2006-01-01

    This study asked whether the concurrent reinforcement of behavioral variability facilitates learning to emit a difficult target response. Sixty students repeatedly pressed sequences of keys, with an originally infrequently occurring target sequence consistently being followed by positive feedback. T

  2. Prototyping of concurrent control systems implemented in FPGA devices

    CERN Document Server

    Wiśniewski, Remigiusz

    2017-01-01

    This book focuses on prototyping aspects of concurrent control systems and their further implementation and partial reconfiguration in programmable devices. Further, it lays out a full prototyping flow for concurrent control systems. Based on a given primary specification, a system is described with an interpreted Petri net, which naturally reflects the concurrent and sequential relationships of the design. The book shows that, apart from the traditional option of static configuration of the entire system, the latest programmable devices (especially FPGAs) offer far more sophistication. Partial reconfiguration allows selected parts of the system to be replaced without having to reprogram the entire structure of the device. Approaches to dynamic and static partial reconfiguration of concurrent control systems are presented and described in detail.< The theoretical work is illustrated by examples drawn from various applications, with a milling machine and a traffic-light controller highlighted as representat...

  3. Process Algebra Approach to Reasoning About Concurrent Actions

    Institute of Scientific and Technical Information of China (English)

    YuanFeng; Ming-ShengYing

    2004-01-01

    A reasonable transition rule is proposed for synchronized actions and some equational properties of bisimilarity and weak bisimilarity in the process algebra for reasoning about concurrent actions are presented.

  4. Partial Orders and Fully Abstract Models for Concurrency

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik

    1990-01-01

    In this thesis sets of labelled partial orders are employed as fundamental mathematical entities for modelling nondeterministic and concurrent processes thereby obtaining so-called noninterleaving semantics. Based on different closures of sets of labelled partial orders, simple algebraic languages...

  5. The Revised UCLA Loneliness Scale: Concurrent and Discriminant Validity Evidence.

    Science.gov (United States)

    Russell, Dan; And Others

    1980-01-01

    Two studies provide methodogical refinement in the measurement of loneliness, using a revised version of the self-report UCLA Loneliness Scale. Investigates response bias, concurrent validity, and correlated measures. (Author/SS)

  6. Finite Element Analysis in Concurrent Processing: Computational Issues

    Science.gov (United States)

    Sobieszczanski-Sobieski, Jaroslaw; Watson, Brian; Vanderplaats, Garrett

    2004-01-01

    The purpose of this research is to investigate the potential application of new methods for solving large-scale static structural problems on concurrent computers. It is well known that traditional single-processor computational speed will be limited by inherent physical limits. The only path to achieve higher computational speeds lies through concurrent processing. Traditional factorization solution methods for sparse matrices are ill suited for concurrent processing because the null entries get filled, leading to high communication and memory requirements. The research reported herein investigates alternatives to factorization that promise a greater potential to achieve high concurrent computing efficiency. Two methods, and their variants, based on direct energy minimization are studied: a) minimization of the strain energy using the displacement method formulation; b) constrained minimization of the complementary strain energy using the force method formulation. Initial results indicated that in the context of the direct energy minimization the displacement formulation experienced convergence and accuracy difficulties while the force formulation showed promising potential.

  7. Service-Oriented Synthesis of Distributed and Concurrent Protocol Specifications

    Directory of Open Access Journals (Sweden)

    Jehad Al Dallal

    2008-01-01

    Full Text Available Several methods have been proposed for synthesizing computer communication protocol specifications from service specifications. Some protocol synthesis methods based on the finite state machine (FSM model assume that primitives in the service specifications cannot be executed simultaneously. Others either handle only controlled primitive concurrency or have tight restrictions on the applicable FSM topologies. As a result, these synthesis methods are not applicable to an interesting variety of inherently concurrent applications, such as the Internet and mobile communication systems. This paper proposes a concurrent-based protocol synthesis method that eliminates the restrictions imposed by the earlier methods. The proposed method uses a synthesis method to obtain a sequential protocol specification (P-SPEC from a given service specification (S-SPEC. The resulting P-SPEC is then remodeled to consider the concurrency behavior specified in the S-SPEC, while guaranteeing that P-SPEC provides the specified service.

  8. DFM/CAPP/CAM System in a Concurrent Engineering Environment

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In this paper the importance of DFM/CAPP/CAM system in Concurrent Engineering (CE) is discussed. Based on the analyses of the character of concurrent product design and manufacturing process design, the workflow of DFM/CAPP/CAM system in CE is given. DFM/CAPP/CAM theories, methods and functions are investigated in a delicate and all-round way, and are implemented in the developed DFM/CAPP/CAM system.

  9. Proceedings 18th International Workshop on Expressiveness in Concurrency

    CERN Document Server

    Luttik, Bas; 10.4204/EPTCS.64

    2011-01-01

    This volume contains the proceedings of the 18th International Workshop on Expressiveness in Concurrency (EXPRESS 2011), which took place on 5th September 2011 in Aachen, as a satellite workshop of CONCUR 2011. The EXPRESS workshop series aim at bringing together researchers who are interested in the expressiveness and comparison of formal models that broadly relate to concurrency. In particular, this also includes emergent fields such as logic and interaction, game-theoretic models, and service-oriented computing.

  10. On Distributed Concurrent Multi-Port Router Test System

    Institute of Scientific and Technical Information of China (English)

    SONG Bo; XU Juan

    2005-01-01

    This paper presents a framework of the distributed concurrent multi-port-testing test system (CMPT-TS) for IP routers under development at Sichuan Network Communication Key Laboratory. Having analyzed the actuality of concurrent testing for routers, this paper develops a distributed architecture of CMPT-TS and discusses its functional components in detail. Moreover, a new test definition language, CMPT definition language, is also introduced simply.

  11. Probabilistic simulation of concurrent engineering of propulsion systems

    Science.gov (United States)

    Chamis, C. C.; Singhal, S. N.

    1993-01-01

    Technology readiness and the available infrastructure is assessed for timely computational simulation of concurrent engineering for propulsion systems. Results for initial coupled multidisciplinary, fabrication-process, and system simulators are presented including uncertainties inherent in various facets of engineering processes. An approach is outlined for computationally formalizing the concurrent engineering process from cradle-to-grave via discipline dedicated workstations linked with a common database.

  12. Local Linearizability for Concurrent Container-Type Data Structures

    OpenAIRE

    Haas, Andreas; Henzinger, Thomas A.; Holzer, Andreas; Kirsch, Christoph M.; Lippautz, Michael; Payer, Hannes; Sezgin, Ali; Sokolova, Ana; Veith, Helmut

    2016-01-01

    The semantics of concurrent data structures is usually given by a sequential specification and a consistency condition. Linearizability is the most popular consistency condition due to its simplicity and general applicability. Nevertheless, for applications that do not require all guarantees offered by linearizability, recent research has focused on improving performance and scalability of concurrent data structures by relaxing their semantics. In this paper, we present local linearizabi...

  13. A case of cerebral malaria and dengue concurrent infection

    Institute of Scientific and Technical Information of China (English)

    Anwar Alam; Md Dm

    2013-01-01

    Cerebral malaria and dengue are the common infections which cause higher mortality and morbidities in every part of the world especially in India. Concurrent infection of cerebral malaria and dengue is rare entity due to different habitat of vectors and it was reported rarely from Southeast Asia. In this case report, the authors reported a case of concurrent cerebral malaria and dengue which was recovered after eight days of admission with increase in morbidity.

  14. Concurrent emphysematous cholecystitis and emphysematous pancreatitis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hee Seok; Lee, Yong Seok; Yoon, Yup [Dongguk University International Hospital, Dongguk University College of Medicine, Goyang (Korea, Republic of); Park, Sung Bin [Ulsan University Hospital, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2008-01-15

    Emphysematous infections of the abdomen and pelvis are potentially life-threatening conditions which require aggressive medical and surgical management. Therefore, early radiographic detection is important in the management of these conditions. Concurrent emphysematous infections involving different organs have been rarely reported, and primarily occur in immunocompromised patients. Here, we report a rare case of concurrent emphysematous cholecystitis and emphysematous pancreatitis in a 97 year old male patient.

  15. Concurrent object-oriented programming: The MP-Eiffel approach

    OpenAIRE

    Silva, Miguel Augusto Mendes Oliveira e

    2004-01-01

    This article evaluates several possible approaches for integrating concurrency into object-oriented programming languages, presenting afterwards, a new language named MP-Eiffel. MP-Eiffel was designed attempting to include all the essential properties of both concurrent and object-oriented programming with simplicity and safety. A special care was taken to achieve the orthogonality of all the language mechanisms, allowing their joint use without unsafe side-effects (such as inh...

  16. Global-Local View: Scalable Consistency for Concurrent Data Types

    OpenAIRE

    Akkoorath, Deepthi Devaki; Brandão, José; Bieniusa, Annette; Baquero, Carlos

    2017-01-01

    Concurrent linearizable access to shared objects can be prohibitively expensive in a high contention workload. Many applications apply ad-hoc techniques to eliminate the need of synchronous atomic updates, which may result in non-linearizable implementations. We propose a new programming model which leverages such patterns for concurrent access to objects in a shared memory system. In this model, each thread maintains different views on the shared object - a thread-local view and a global vie...

  17. Concurrent validity of the Armour39 heart rate monitor strap.

    Science.gov (United States)

    Flanagan, Shawn D; Comstock, Brett A; Dupont, William H; Sterczala, Adam R; Looney, Dave P; Dombrowski, Dylan H; McDermott, Danielle M; Bryce, Alexander; Maladouangdock, Jesse; Dunn-Lewis, Courtenay; Luk, Hui-Ying; Szivak, Tunde K; Hooper, David R; Kraemer, William J

    2014-03-01

    New technology offers potential advantages in physically demanding environments where convenience and comfort are important and accurate and reliable data collection is challenging. Nevertheless, it is important to validate the accuracy and reliability of such biological monitoring systems (BMS) before they are adopted. The purpose of this investigation was to assess the concurrent validity of a new heart rate monitor across a range of exercise intensities and with a large and diverse group of male subjects in a large cohort with diverse physical fitness characteristics. Seventy-five men (age, 23 ± 4 years; height, 181 ± 8 cm; body mass, 83 ± 12 kg; estimated V[Combining Dot Above]O2peak, 3.16 ± 0.63 [L·min]) volunteered and completed a graded cycle ergometer exercise protocol while heart rate was continuously monitored before, during, and after exercise with the new device (Armour39) and the gold standard (electrocardiogram). The 2-minute stages included sitting, standing, and cycling with 35 W increments until volitional fatigue. The coefficient of determination between mean heart rate values at each stage was R = 0.99, whereas Pearson correlations (r) at each stage were ≥ 0.99. Heart rates during exercise were typically within 1 beat of each other. The Armour39 BMS, therefore, is an acceptable means for the valid and reliable determination of heart rate under various bodily positions and levels of exertion, including maximal exercise intensity.

  18. Neural Representation of Concurrent Vowels in Macaque Primary Auditory Cortex.

    Science.gov (United States)

    Fishman, Yonatan I; Micheyl, Christophe; Steinschneider, Mitchell

    2016-01-01

    Successful speech perception in real-world environments requires that the auditory system segregate competing voices that overlap in frequency and time into separate streams. Vowels are major constituents of speech and are comprised of frequencies (harmonics) that are integer multiples of a common fundamental frequency (F0). The pitch and identity of a vowel are determined by its F0 and spectral envelope (formant structure), respectively. When two spectrally overlapping vowels differing in F0 are presented concurrently, they can be readily perceived as two separate "auditory objects" with pitches at their respective F0s. A difference in pitch between two simultaneous vowels provides a powerful cue for their segregation, which in turn, facilitates their individual identification. The neural mechanisms underlying the segregation of concurrent vowels based on pitch differences are poorly understood. Here, we examine neural population responses in macaque primary auditory cortex (A1) to single and double concurrent vowels (/a/ and /i/) that differ in F0 such that they are heard as two separate auditory objects with distinct pitches. We find that neural population responses in A1 can resolve, via a rate-place code, lower harmonics of both single and double concurrent vowels. Furthermore, we show that the formant structures, and hence the identities, of single vowels can be reliably recovered from the neural representation of double concurrent vowels. We conclude that A1 contains sufficient spectral information to enable concurrent vowel segregation and identification by downstream cortical areas.

  19. The HSE Management Standards Indicator Tool: concurrent and construct validity.

    Science.gov (United States)

    Marcatto, F; Colautti, L; Larese Filon, F; Luis, O; Ferrante, D

    2014-07-01

    The Health & Safety Executive Management Standards Indicator Tool (HSE-MS IT) is a questionnaire commonly used to assess work-related stress risks at an organizational level. A critical factor in determining whether this instrument is actually useful is that higher levels of stress risk in the work-design domains should predict higher levels of stress and stress-related outcomes in workers. Only a few studies, however, have addressed this issue. To test both the concurrent and construct validity of the HSE-MS IT, by relating it with another widely used instrument, the Job Content Questionnaire (JCQ), and by examining its relationships with a set of work-related stress outcomes. An anonymous cross-sectional questionnaire was administered to a sample of employees in an Italian municipality. The questionnaire included the HSE-MS IT, self-reported measures of job satisfaction, job motivation and stress at work, the Satisfaction with Life Scale and the reduced form of the JCQ. A total of 760 out of 779 employees completed the questionnaire. Results showed moderate to strong correlation among the corresponding HSE-MS IT and JCQ scales. Hierarchical regression highlighted the specific contribution of each of the HSE-MS IT scales in predicting three relevant work-related stress outcomes (self-reported stress, job satisfaction and job motivation), after controlling for gender, age and life satisfaction. Our findings consolidated the HSE-MS IT validity and showed the specific sensitivity of its scales to assess different aspects of work-related distress, including self-perception of stress at work. These results can have practical implications for the occupational well-being of employees. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Genetic algorithm guided population pharmacokinetic model development for simvastatin, concurrently or non-concurrently co-administered with amlodipine.

    Science.gov (United States)

    Chaturvedula, Ayyappa; Sale, Mark E; Lee, Howard

    2014-02-01

    An automated model development was performed for simvastatin, co-administered with amlodipine concurrently or non-concurrently (i.e., 4 hours later) in 17 patients with coexisting hyperlipidemia and hypertension. The single objective hybrid genetic algorithm (SOHGA) was implemented in the NONMEM software by defining the search space for structural, statistical and covariate models. Candidate models obtained from the SOHGA runs were further assessed for biological plausibility and the precision of parameter estimates, followed by traditional backward elimination process for model refinement. The final population pharmacokinetic model shows that the elimination rate constant for simvastatin acid, the active form by hydrolysis of its lactone prodrug (i.e., simvastatin), is only 44% in the concurrent amlodipine administration group compared with the non-concurrent group. The application of SOHGA for automated model selection, combined with traditional model selection strategies, appears to save time for model development, which also can generate new hypotheses that are biologically more plausible.

  1. Phase I Trial of Escalating-dose Cisplatin with 5-fluorouracil and Concurrent Radiotherapy in Chinese Patients with Esophageal Cancer

    Directory of Open Access Journals (Sweden)

    Zhao,Yan-Nan

    2008-02-01

    Full Text Available We defined the maximum-tolerated dose (MTD of chemoradiotherapy (cisplatin (CDDP with 5-fluorouracil (5-FU and concurrent chemoradiotherapy for Chinese patients with esophageal cancer. Twenty-one previously untreated patients with primary esophageal cancer were entered into this study. Escalating doses of CDDP with 5-FU were administered in a modified Fibonacci sequence, with concurrent conventional fractionation radiotherapy (CFR of 60 Gy or 50 Gy. The starting doses were CDDP 37.5 mg/m2 on day 1, and 5-FU 500 mg/m2 on days 1-5, respectively. The regimen was repeated 4 times every 28 days. If no dose-limiting toxicity (DLT was observed, the next dose level was applied. The procedures were repeated until DLT appeared. The MTD was declared to be 1 dose level below the level at which DLT appeared. DLT was grade 3 radiation-induced esophagitis at a dose level of CDDP 60 mg/m2 with 5-FU 700 mg/m2 and concurrent 60 Gy CFR. MTD was defined as CDDP 52.5 mg/m2 with 5-FU 700 mg/m2 and concurrent 50 Gy CFR. The MTD of CDDP with 5-FU and in concurrent chemoradiotherapy for Chinese patients with esophageal cancer is CDDP 52.5 mg/m2 on day 1 and 5FU 700 mg/m2 on days 1-5, repeated 4 times every 28 days, and concurrent 50 Gy CFR. Further evaluation of this regimen in a prospective phase II trial is ongoing.

  2. Phase I trial of escalating-dose cisplatin with 5-fluorouracil and concurrent radiotherapy in Chinese patients with esophageal cancer.

    Science.gov (United States)

    Lin, Qiang; Gao, Xian-Shu; Qiao, Xue-Ying; Zhou, Zhi-Guo; Zhang, Ping; Chen, Kun; Zhao, Yan-Nan; Asaumi, Junichi

    2008-02-01

    We defined the maximum-tolerated dose (MTD) of chemoradiotherapy (cisplatin (CDDP) with 5-fluorouracil (5-FU) and concurrent chemoradiotherapy) for Chinese patients with esophageal cancer. Twenty-one previously untreated patients with primary esophageal cancer were entered into this study. Escalating doses of CDDP with 5-FU were administered in a modified Fibonacci sequence, with concurrent conventional fractionation radiotherapy (CFR) of 60 Gy or 50 Gy. The starting doses were CDDP 37.5 mg/m2 on day 1, and 5-FU 500 mg/m2 on days 1-5, respectively. The regimen was repeated 4 times every 28 days. If no dose-limiting toxicity (DLT) was observed, the next dose level was applied. The procedures were repeated until DLT appeared. The MTD was declared to be 1 dose level below the level at which DLT appeared. DLT was grade 3 radiation-induced esophagitis at a dose level of CDDP 60 mg/m2 with 5-FU 700 mg/m2 and concurrent 60 Gy CFR. MTD was defined as CDDP 52.5 mg/m2 with 5-FU 700 mg/m2 and concurrent 50 Gy CFR. The MTD of CDDP with 5-FU and in concurrent chemoradiotherapy for Chinese patients with esophageal cancer is CDDP 52.5 mg/m2 on day 1 and 5FU 700 mg/m2 on days 1-5, repeated 4 times every 28 days, and concurrent 50 Gy CFR. Further evaluation of this regimen in a prospective phase II trial is ongoing.

  3. 齐多拉米双夫定片微生物检查方法研究%Methodological study on microbial limit test of Zidovudine and Lamivudine tablets

    Institute of Scientific and Technical Information of China (English)

    吴中华

    2015-01-01

    According to the Chinese pharmacopieia ( 2010 Edition ) , an accurate method for microbial limit test of Zidovudine and Lamivudine tablets was established in this study.Membrane filtration and/or direct plate culture were taken for counting bacteria, mold and yeast using E.coli as the controls.%建立齐多拉米双夫定片微生物检查方法。方法取齐多拉米双夫定片,按《中国药典》2010版二部附录所载的“微生物限度检查法”项下方法试验,结果表明:采用薄膜过滤法测定细菌数,平皿法测定霉菌和酵母菌数,薄膜过滤法检查控制菌大肠埃希菌。

  4. Graph-Based Decision Making for Task Scheduling in Concurrent Gaudi

    CERN Document Server

    Shapoval, Illya; Hegner, Benedikt; Funke, Daniel; Piparo, Danilo; Mato Vila, Pere

    2015-01-01

    The modern trend of extensive levels of hardware parallelism and heterogeneity pushes software to evolve through a paradigm shift towards concurrent data processing architectures. One such striking example in the domain of high-energy physics is represented by Gaudi – an experiment independent software framework, used in two of four major experiments of the Large Hadron Collider project, and in several others. The framework is responsible for event processing by means of hundreds of algorithms which have logical and data dependencies between each other. Historically, the framework was designed being inherently sequential, meaning that at any time of data processing there is only one event being processed and only one algorithm being executed on it. This allowed to respect the dependencies of algorithms by just organizing them in a well-defined execution path to be run on CPU. The evolution of the Gaudi framework into its concurrent incarnation, though, implies the necessity to split the execution path dynam...

  5. Proceedings Second International Workshop on Programming Language Approaches to Concurrency and Communication-cEntric Software

    CERN Document Server

    Beresford, Alastair R; 10.4204/EPTCS.17

    2010-01-01

    The Second International Workshop on Programming Language Approaches to Concurrency and Communication-cEntric Software (PLACES) was co-located with ETAPS 2009 in the city of York, England. The workshop took place on Sunday 22nd March 2009. The workshop focused on the challenges raised by the changing landscape of computer software. Traditionally, most software was written for a single computer with one CPU. However applications on the web today are built using numerous interacting services deployed on across many machines; soon off-the-shelf CPUs will host thousands of cores, and sensor networks will be composed from a large number of processing units. Many normal applications will soon need to make effective use of thousands of computing nodes. At some level of granularity, computation in such systems will be inherently concurrent and communication-centred. The development of effective programming methodologies for the coming computing paradigm demands exploration and understanding of a wide variety of ideas...

  6. Concurrent cerebellar and cervical intramedullary tuberculoma: Paradoxical response on antitubercular chemotherapy and need for surgery

    Science.gov (United States)

    Das, Kuntal Kanti; Jaiswal, Sushila; Shukla, Mukesh; Srivastava, Arun Kumar; Behari, Sanjay; Kumar, Raj

    2014-01-01

    Spinal intramedullary tuberculoma (SIT) is a rare manifestation of neurotuberculosis. Concurrent SIT and intracranial tuberculoma are further unusual. Most of these tuberculomas respond completely to medical therapy, and surgical excision is seldom required. In this report, we describe a 17-year-old boy who developed cervical intramedullary tuberculoma at C3-C6 level with a concurrent lesion involving the right cerebellar hemisphere while on treatment for tubercular meningitis. This patient had paradoxical increase in size of the cervical lesion even though the cerebellar lesion showed regression in size. In this article, we discuss the paradoxical response to anti-tubercular therapy in central nervous system tuberculosis, possible causes of nonresolution of tuberculoma on medical therapy and evaluate the role of surgery in these cases. PMID:25250077

  7. ComPoScan: Adaptive Scanning for Efficient Concurrent Communications and Positioning with 802.11

    DEFF Research Database (Denmark)

    King, Thomas; Kjærgaard, Mikkel Baun

    2008-01-01

    active scanning to allow positioning and to minimize the impact on the data flow. The system is configurable to realize different trade-offs between position accuracy and the level of communication interruption. We provide extensive experimental results by emulation on data collected at several sites......Using 802.11 concurrently for communications and positioning is problematic, especially if location-based services (e.g., indoor navigation) are concurrently executed with real-time applications (e.g., VoIP, video conferencing). Periodical scanning for measuring the signal strength interrupts...... the data flow. Reducing the scan frequency is no option because it hurts the position accuracy. For this reason, we need an adaptive technique to mitigate this problem. This work proposes ComPoScan which, based on movement detection, adaptively switches between light-weight monitor sniffing and invasive...

  8. High-concurrence steady-state entanglement of two hole spins in a quantum dot molecular

    CERN Document Server

    Yang, Song; Li, ChuanFeng; Zou, XuBo; Guo, GuangCan

    2009-01-01

    Entanglement, a non-trivial phenomena manifested in composite quantum system, can be served as a new type of physical resource in the emerging technology of quantum information and quantum computation. However, a quantum entanglement is fragile to the environmental-induced decoherence. Here, we present a novel way to prepare a high-concurrence steady-state entanglement of two hole spins in a quantum dot molecular via optical pumping of trion levels. In this scheme, the spontaneous dispassion is used to induce and stabilize the entanglement with rapid rate. It is firstly shown that under certain conditions, two-qubit singlet state can be generated without requiring the state initialization. Then we study the effect of acoustic phonons and electron tunnelings on the scheme, and show that the concurrence of entangled state can be over 0.95 at temperature $T = 1 $K.

  9. Comparing concurrence and negativity in time-dependent ionic-phononic system with fifteen dimensional density matrix

    Science.gov (United States)

    Dermez, Rasim

    2016-10-01

    It is solved a time-dependent Hamiltonian using a unitary transformation method which Λ(t) type is used to engineer a cascade Ξ scheme interaction between the vibrational phonons and trapped three-level ion. Quantum entanglement is characterized by comparing concurrence and negativity of the time-dependent ionic-phononic system. In this quantum system, we obtain that the amount of concurrence can be tuned between 0 and 0.99 while the amount of negativity changes between 0 and 0.49.

  10. Sequential and concurrent exposure of flour beetles ( Tribolium confusum ) to tapeworms ( Hymenolepis diminuta ) and pesticide (diatomaceous earth).

    Science.gov (United States)

    Shostak, Allen W

    2012-06-01

    The response of Tribolium confusum to sublethal levels of 2 environmental stressors was studied, i.e., parasitic infection represented by the cestode Hymenolepis diminuta , and a physical stressor represented by the natural pesticide diatomaceous earth (DE). These were applied sequentially (DE, then infection) to detect indirect or carryover effects of DE, and concurrently (DE applied immediately after exposure to parasites and DE presence maintained throughout the infection) to detect direct effects of DE. DE alone, but not parasitism alone, produced significant host mortality, and concurrent treatment with DE and parasitism did not increase mortality over DE alone. Parasite abundance was significantly higher following sequential, but not concurrent, DE exposure. Parasite abundance in mated hosts was significantly higher than in virgin hosts. Parasitic infection resulted in significantly fewer eggs retained in the oviduct of beetles, but there was no difference in the number of eggs that accumulated in the culture medium and no difference in the surface-seeking behavior of beetles. Mating status of beetles in all treatments, and DE exposure in concurrent treatments significantly increased their surface-seeking behavior. Concurrent exposure to DE also resulted in a 4- to 6-fold increase in host egg numbers that accumulated in the culture medium. Although DE exposure increased parasite numbers in the beetles, these 2 stressors otherwise appeared to act independently.

  11. Who would benefit from memory training? A pilot study examining the ceiling effect of concurrent cognitive stimulation

    Directory of Open Access Journals (Sweden)

    Kwok TCY

    2011-03-01

    Full Text Available Timothy CY Kwok1,2, Wai Wang Chau1, Kenneth SL Yuen1,3, Anita YM Wong4, Jessie CY Li1, Rebecca YY Shiu4, Florence KY Ho11Jockey Club Centre for Positive Ageing, Hong Kong; 2Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong; 3Laboratory of Neuropsychology, Department of Psychology, University of Hong Kong, Pokfulam, Hong Kong; 4The Hong Kong Chinese Women's Club Madam Wong Chan Sook Ying Memorial Care and Attention Home for the Aged, Hong KongAbstract: Diverse effects of memory training were observed in the literature. One possible factor is the amount of concurrent cognitive training received during the training program. In this pilot study, we recruited 24 elderly adults with or without concurrent cognitive stimulations to attend a memory-training program. Findings suggested that elderly people without concurrent cognitive stimulation could benefit from a memory-training program in the form of improved initiation and memory functioning. Self-rated quality of life measure also showed improvements alongside the cognitive benefits. Elderly people with regular concurrent cognitive stimulation, on the other hand, seemed to plateau in their level of performance and did not show any significant change. Our preliminary findings suggested nonlinear concurrent cognitive stimulation in the elderly.Keywords: memory training, cognitive training, dementia, Chinese, elderly 

  12. Effects of Physiological Internal Noise on Model Predictions of Concurrent Vowel Identification for Normal-Hearing Listeners.

    Science.gov (United States)

    Hedrick, Mark S; Moon, Il Joon; Woo, Jihwan; Won, Jong Ho

    2016-01-01

    Previous studies have shown that concurrent vowel identification improves with increasing temporal onset asynchrony of the vowels, even if the vowels have the same fundamental frequency. The current study investigated the possible underlying neural processing involved in concurrent vowel perception. The individual vowel stimuli from a previously published study were used as inputs for a phenomenological auditory-nerve (AN) model. Spectrotemporal representations of simulated neural excitation patterns were constructed (i.e., neurograms) and then matched quantitatively with the neurograms of the single vowels using the Neurogram Similarity Index Measure (NSIM). A novel computational decision model was used to predict concurrent vowel identification. To facilitate optimum matches between the model predictions and the behavioral human data, internal noise was added at either neurogram generation or neurogram matching using the NSIM procedure. The best fit to the behavioral data was achieved with a signal-to-noise ratio (SNR) of 8 dB for internal noise added at the neurogram but with a much smaller amount of internal noise (SNR of 60 dB) for internal noise added at the level of the NSIM computations. The results suggest that accurate modeling of concurrent vowel data from listeners with normal hearing may partly depend on internal noise and where internal noise is hypothesized to occur during the concurrent vowel identification process.

  13. Concurrent laparoscopic morgagni hernia repair and sleeve gastrectomy.

    Science.gov (United States)

    Chiou, Grace; Tedesco, Maureen; Eisenberg, Dan

    2012-12-01

    The Morgagni-type anterior diaphragmatic hernia is a congenital defect that is a very uncommon hernia presenting in an adult. Surgical repair is usually recommended upon diagnosis and often requires synthetic mesh for a durable, tension-free repair. The use of synthetic mesh concurrently with several of bariatric operations is controversial owing to the potential for mesh infection. In this report we describe a laparoscopic repair of a symptomatic Morgagni hernia with synthetic mesh, concurrently with sleeve gastrectomy, in a morbidly obese man. The patient was a 58-year-old man with a body mass index of 48 kg/m(2) and associated co-morbid conditions that included obstructive sleep apnea, hypertension, hyperlipidemia, impaired fasting glucose, and osteoarthritis. He was diagnosed with Morgagni hernia with exertional dyspnia. He underwent concurrent laparoscopic Morgagni hernia repair with mesh and sleeve gastrectomy. At 2 months after surgery the patient was doing well and tolerating solid foods, and his percentage excess weight loss was 35%. He was exercising regularly and had no exertional dyspnea. Laparoscopy is an attractive approach to performing multiple intra-abdominal procedures concurrently. The Morgagni hernia repair with mesh can be performed safely and effectively using a laparoscopic approach. This can be performed concurrently with bariatric surgery in the morbidly obese.

  14. Strategy of Concurrent Optimization for an Assembly Sequence

    Institute of Scientific and Technical Information of China (English)

    YANG Bo; LIU Lu-ning; ZE Xiang-bo

    2005-01-01

    An effective constraint release based approach to realize concurrent optimization for an assembly sequence is proposed. To quantify the measurement of assembly efficiency, a mathematical model of concurrency evaluation index was put forward at first, and then a technology to quantify assembly constraints was developed by application of some fuzzy logic algorithms. In the process of concurrent optimization of the assembly sequence, two kinds of constraints were involved. One was self-constraints of components, which was used to evaluate the assemble capability of components under the condition of full-freedom. Another was an assembly constraint between components represented by geometric constraints between points, lines and planes under physical restriction conditions. The concept of connection strength degree (CSD) was introduced as one efficient indicator and the value of it was evaluated by the intersection of the two constraints mentioned above. The equivalent constraints describing the connection weights between components were realized by a well designed constraints reduction, and then the connection weights based complete assembly liaison graph was applied to release virtual connections between components. Under a given threshold value, a decomposition and reconstituting strategy for the graph with the focus on high assembly concurrency was used to realize an optimized assembly concurrency evaluation index. Finally, the availability of the approach was illustrated in an example to optimize the assembly of a shift pump.

  15. Security of attachment to spouses in late life: Concurrent and prospective links with cognitive and emotional wellbeing.

    Science.gov (United States)

    Waldinger, Robert J; Cohen, Shiri; Schulz, Marc S; Crowell, Judith A

    2015-06-01

    Social ties are powerful predictors of late-life health and wellbeing. Although many adults maintain intimate partnerships into late life, little is known about mental models of attachment to spouses and how they influence aging. Eighty-one elderly heterosexual couples (162 individuals) were interviewed to examine the structure of attachment security to their partners and completed measures of cognition and wellbeing concurrently and 2.5 years later. Factor analysis revealed a single factor for security of attachment. Higher security was linked concurrently with greater marital satisfaction, fewer depressive symptoms, better mood, and less frequent marital conflicts. Greater security predicted lower levels of negative affect, less depression, and greater life satisfaction 2.5 years later. For women, greater security predicted better memory 2.5 years later and attenuated the link between frequency of marital conflict and memory deficits. Late in life, mental models of attachment to partners are linked to wellbeing concurrently and over time.

  16. 26 CFR 31.3121(s)-1 - Concurrent employment by related corporations with common paymaster.

    Science.gov (United States)

    2010-04-01

    ... concurrently employed individuals under this section by one combined paycheck, drawn on a single bank account... artisans, all of whom are concurrently employed by two or more of the corporations during the calendar year... artisans who are concurrently employed by W and X. (b) A is an executive who is concurrently employed...

  17. Concurrent Structural Fatigue Damage Prognosis Under Uncertainty

    Science.gov (United States)

    2014-04-30

    level is approximately 57% of the maximum loading without effects left by the overload. The forth diamond symbol is slightly smaller than before (the...Rackwitz, R.a.F., B, Structural Reliablity Under Combined Random Load Sequences. Computers & Structures, 1978. 9(5): p. 484-494. 67. Porter , T.R...mechanically polished (one micron diamond suspension in the last step), which provides a mirror-like surface to facilitate the optical crack length

  18. Concurrent Engineering Oriented CAx/DFx Information Integration

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The information integration, especially in CAD/CAPP/CAM, is a basis for realizing the integrated and concurrent product development in Concurrent Engineering (CE) environment. The integration technology based on STEP application protocol gives an effective way for the CAx/DFx information integration. This paper discusses the characteristics of concurrent product development, analyzes the methodology and technology of STEP, proposes an information integration approach based on STEP AP214, and presents the strategy of product data integration and an integration system implementation architecture. The integration technology based on STEP application protocol and the ST-Developer tools is realized in a prototype system to support product data integration between CAD and its follow-up systems through STEP physical file and STEP information exchange interface.

  19. Formal Relationships Between Geometrical and Classical Models for Concurrency

    CERN Document Server

    Goubault, Eric

    2010-01-01

    A wide variety of models for concurrent programs has been proposed during the past decades, each one focusing on various aspects of computations: trace equivalence, causality between events, conflicts and schedules due to resource accesses, etc. More recently, models with a geometrical flavor have been introduced, based on the notion of cubical set. These models are very rich and expressive since they can represent commutation between any bunch of events, thus generalizing the principle of true concurrency. While they seem to be very promising - because they make possible the use of techniques from algebraic topology in order to study concurrent computations - they have not yet been precisely related to the previous models, and the purpose of this paper is to fill this gap. In particular, we describe an adjunction between Petri nets and cubical sets which extends the previously known adjunction between Petri nets and asynchronous transition systems by Nielsen and Winskel.

  20. Mathematical techniques for analyzing concurrent and probabilistic systems

    CERN Document Server

    Rutten, J J M M; Panangaden, Prakash; Panangaden, Prakash; Breugel, Franck van

    2004-01-01

    The book consists of two sets of lecture notes devoted to slightly different methods of analysis of concurrent and probabilistic computational systems. The first set of lectures develops a calculus of streams (a generalization of the set of natural numbers) based on the coinduction principle coming from the theory of coalgebras. It is now well understood that the interplay between algebra (for describing structure) and coalgebra (for describing dynamics) is crucial for understanding concurrent systems. There is a striking analogy between streams and formula calculus reminiscent to those appearing in quantum calculus. These lecture notes will appeal to anyone working in concurrency theory but also to algebraists and logicians. The other set of lecture notes focuses on methods for automatically verifying probabilistic systems using techniques of model checking. The unique aspect of these lectures is the coverage of both theory and practice. The authors have been responsible for one of the most successful experi...

  1. Concurrent negotiation and coordination for grid resource coallocation.

    Science.gov (United States)

    Sim, Kwang Mong; Shi, Benyun

    2010-06-01

    Bolstering resource coallocation is essential for realizing the Grid vision, because computationally intensive applications often require multiple computing resources from different administrative domains. Given that resource providers and consumers may have different requirements, successfully obtaining commitments through concurrent negotiations with multiple resource providers to simultaneously access several resources is a very challenging task for consumers. The impetus of this paper is that it is one of the earliest works that consider a concurrent negotiation mechanism for Grid resource coallocation. The concurrent negotiation mechanism is designed for 1) managing (de)commitment of contracts through one-to-many negotiations and 2) coordination of multiple concurrent one-to-many negotiations between a consumer and multiple resource providers. The novel contributions of this paper are devising 1) a utility-oriented coordination (UOC) strategy, 2) three classes of commitment management strategies (CMSs) for concurrent negotiation, and 3) the negotiation protocols of consumers and providers. Implementing these ideas in a testbed, three series of experiments were carried out in a variety of settings to compare the following: 1) the CMSs in this paper with the work of others in a single one-to-many negotiation environment for one resource where decommitment is allowed for both provider and consumer agents; 2) the performance of the three classes of CMSs in different resource market types; and 3) the UOC strategy with the work of others [e.g., the patient coordination strategy (PCS )] for coordinating multiple concurrent negotiations. Empirical results show the following: 1) the UOC strategy achieved higher utility, faster negotiation speed, and higher success rates than PCS for different resource market types; and 2) the CMS in this paper achieved higher final utility than the CMS in other works. Additionally, the properties of the three classes of CMSs in

  2. Concurrent Chemoradiotherapy in Elderly Patients with Locally Advanced Esophageal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Bae Kwon; Kang, Ki Mun; Chai, Gyu Young [Gyeongsang Institute of Health Sciences, Jinju (Korea, Republic of); Lee, Gyeong Won; Kang, Jung Hoon; Kim, Hoon Gu; Lee, Won Seob [Gyeongsang National University, Jinju (Korea, Republic of)

    2009-06-15

    The effect of concurrent chemoradiotherapy was analyzed in elderly patients when used in the treatment of locally advanced esophageal cancer. The retrospective analysis included 28 elderly patients aged 65 or older, with histopathologically confirmed squamous cell carcinoma of the esophagus, underwent concurrent chemoradiotherapy from January 2001 to July 2007. The squamous cell carcinoma disease stages included 8 patients (28.8%) in stage IIa, 10 patients (35.7%) in stage IIb, and 10 patients (35.7%) in stage III. Fractionated radiotherapy was performed with a 6 MV or 10 MV X-ray for 45{approx}63 Gy (median: 59.4 Gy). Chemotherapy was applied concurrently with the initiation of radiotherapy. A 75 mg/m2 dose of Cisplatin was intravenously administered on day 1. Further, 5-FU 1,000 mg/m2 was continuously administered intravenously from days 1 to 4. This regimen was performed twice at 3-week intervals during radiotherapy. Two cycles of consolidation chemotherapy was performed after radiotherapy. The follow-up period was 3{approx}72 months (median: 19 months). The treatment responses after concurrent chemoradiotherapy included a complete response in 11 patients (39.3%), a partial response in 14 patients (50.0%), and no response in 3 patients (10.7%). The overall response rate was 89.3% (25 patients). The overall 1-, 2- and 3-year survival rates were 55.9%, 34.6% and 24.2%, respectively. The median survival time was 15 months. Two-year survival rates of patients with a complete response, partial response, and no response were 46.2%, 33.0%, and 0%, respectively. The stage and tumor response after concurrent chemoradiotherapy were statistically significant prognostic factors related with survival. No treatment-related deaths occurred in this study. Concurrent chemoradiotherapy is a relatively effective treatment without serious complications in elderly patients with locally-advanced esophageal cancer.

  3. Concurrent functional endoscopic sinus surgery and septorhinoplasty: using evidence to make clinical decisions.

    Science.gov (United States)

    Patel, Zara M; Setzen, Michael; Sclafani, Anthony P; Del Gaudio, John M

    2013-06-01

    Concurrent septorhinoplasty (SRP) and functional endoscopic sinus surgery (FESS) has been a controversial topic in the literature over the last decade. Warnings and admonitions about the risks of performing these procedures together in a single surgery are both published and voiced at national meetings. Although pros and cons have been discussed in the literature, there have been no guidelines published based solely on a review of the level of evidence. A systematic review of the literature was performed and the Clinical Practice Guideline Manual, Conference on Guideline Standardization (COGS), and the Appraisal of Guidelines and Research Evaluation (AGREE) instrument recommendations were followed. Study inclusion criteria were an adult population >18 years old, description or implication of study design available, concurrent FESS and SRP performed without additional procedures, and report of complications included in the study. We identified and evaluated the literature meeting those criteria: 11 retrospective studies. The literature was reviewed for both quality of research design as well as benefit and harm of the proposed interventions. If a patient is in need of FESS and SRP, either for functional or cosmetic reasons, and is found on the risk matrix to either have low or moderate risk, that patient is a good candidate for a concurrent procedure. If the patient is found to have higher risk, it is not an absolute contraindication, but the surgeon must use best clinical judgment when deciding to move forward and must counsel the patient preoperatively about possible increased risks. © 2013 ARS-AAOA, LLC.

  4. Securing the safety net: concurrent participation in income eligible assistance programs.

    Science.gov (United States)

    Gilbert, Danielle; Nanda, Joy; Paige, David

    2014-04-01

    Participation in women, infants and children (WIC), supplemental nutritional assistance program (SNAP), temporary assistance for needy families (TANF), and medical assistance program (MAP) programs provide critical nutrition and health benefits to low-income families. Concurrent enrollment in these programs provides a powerful safety net, yet simultaneous participation is reported to be low. Underutilization undermines program objectives, client well-being and food security. This paper examines concurrent participation among the most needy WIC clients, those at/below 100% of the federal poverty level (FPL), in SNAP, TANF and MAP. We examined the Maryland state WIC program infant electronic database (N = 34,409) for the 12-month period ending September 2010. Our analysis focused on two-thirds of these infants (N = 23,065) who were at/below the 100% FPL. Mothers' mean age was 26.8 ± 6 years; 20.6% White; 52.7% African American, and 23.4% Hispanic. Approximately 10% of infants weighed barriers to concurrent participation among these families.

  5. Heat Treatment of Die and Mould Oriented Concurrent Design

    Institute of Scientific and Technical Information of China (English)

    LI Xiong; ZHANG Hong-bing; RUAN Xue-yu; LUO Zhong-hua; ZHANG Yan

    2006-01-01

    Many disadvantages exist in the traditional die design method which belongs to serial pattern. It is well known that heat treatment is highly important to the dies. A new idea of concurrent design for heat treatment process of die and mould was developed in order to overcome the existent shortcomings of heat treatment process. Heat treatment CAD/CAE was integrated with concurrent circumstance and the relevant model was built. These investigations can remarkably improve efficiency, reduce cost and ensure quality of R and D for products.

  6. Concurrent engineering and product models in seafood companies

    DEFF Research Database (Denmark)

    Jonsdottir, Stella; Vesterager, Johan; Børresen, Torger

    1998-01-01

    Concurrent Engineering (CE) can provide an improved approach to product development for extending the lines of seafood products. Information technology (IT) support tools based on product models can provide an integrated and simultaneous approach for specifying new recipes. The seafood industry can...... benefit from the CE approach which can support product developers to provide concurrent specifications for raw materials, ingredients, packaging, and production methods. The approach involves the use of product models from which line extensions are more easily generated than by use of customary stepwise...

  7. Concurrent engineering: Spacecraft and mission operations system design

    Science.gov (United States)

    Landshof, J. A.; Harvey, R. J.; Marshall, M. H.

    1994-01-01

    Despite our awareness of the mission design process, spacecraft historically have been designed and developed by one team and then turned over as a system to the Mission Operations organization to operate on-orbit. By applying concurrent engineering techniques and envisioning operability as an essential characteristic of spacecraft design, tradeoffs can be made in the overall mission design to minimize mission lifetime cost. Lessons learned from previous spacecraft missions will be described, as well as the implementation of concurrent mission operations and spacecraft engineering for the Near Earth Asteroid Rendezvous (NEAR) program.

  8. Separative power of an optimised concurrent gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Bogovalov, Sergey; Boman, Vladimir [National Research Nuclear University (MEPHI), Moscow (Russian Federation)

    2016-06-15

    The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s)2(300 K/T)(L/1 m) kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  9. Separative Power of an Optimised Concurrent Gas Centrifuge

    Directory of Open Access Journals (Sweden)

    Sergey Bogovalov

    2016-06-01

    Full Text Available The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s2(300 K/T(L/1 m kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  10. Molecular concordance of concurrent Candida albicans candidemia and candiduria.

    Science.gov (United States)

    Huang, Po-Yen; Hung, Min-Hui; Shie, Shian-Sen; Su, Lin-Hui; Chen, Ke-Yuan; Ye, Jung-Jr; Chiang, Ping-Cheng; Leu, Hsieh-Shong; Huang, Ching-Tai

    2013-07-01

    The significance of candiduria remains unclear. We correlated Candida albicans candidemia with candiduria by molecular genotyping. 33 pairs of concurrent blood and urine C. albicans isolates from 31 adult (≥ 18 years) were genotyped with infrequent-restriction-site PCR. The molecular concordance rates of three major genotypes were 100% for I, 82% for II, and 71% for III. The molecular concordance between concurrent C. albicans candidemia and candiduria was frequent. Our findings substantiate the importance of candiduria in appropriate clinical context as the majority of our patients were from intensive care units.

  11. Clinical evidence in concurrence of retinitis pigmentosa and glaucoma

    Institute of Scientific and Technical Information of China (English)

    WANG Mei; LIN Hao-tian; BAI Yu-jing; GE Jian; ZHUO Ye-hong

    2011-01-01

    Glaucoma is rarely complicated by retinitis pigmentosa (RP). To provide clinical evidences for this rare situation, we report the concurrence of these two diseases in two children of a Chinese family. In the present two-child Chinese family without positive history, the older sister presented with bilateral sector RP and coexisting chronic angle-closure glaucoma,and the brother with bilateral whole RP but without coexisting glaucoma. Clinical evidences in concurrence of variants of RP and glaucoma because of possible different gene mutations from the same genetic background represent a rare situation, which may provide clues for future researches in molecular pathogenesis of these rare diseases.

  12. Concurrent recall of serially learned visual discrimination problems in dwarf goats (Capra hircus).

    Science.gov (United States)

    Langbein, J; Siebert, K; Nuernberg, G

    2008-11-01

    Studies of cognitive ability in farm animals are valuable, not only because they provide indicators of the commonality of comparative influence, but understanding farm animal cognition may also aid in management and treatment procedures. Here, eight dwarf goats (Capra hircus) learned a series of 10 visual four-choice discriminations using an automated device that allowed individual ad lib. access to the test setup while staying in a familiar environment and normal social setting. The animals were trained on each problem for 5 days, followed by concurrent testing of the current against the previous problem. Once all 10 problems had been learned, they were tested concurrently over the course of 9 days. In initial training, all goats achieved criterion learning levels on nearly all problems within 2 days and under 200 trials. Concurrently presenting the problems trained in adjacent sessions did not impair performance on either problem relative to single-problem learning. Upon concurrent presentation of all 10 previously learned problems, at least half were well-remembered immediately. Although this test revealed a recency effect (later problems were better remembered), many early-learned problems were also well-retained, and 10-item relearning was quite quick. These results show that dwarf goats can retain multiple-problem information proficiently and can do so over periods of several weeks. From an ecological point of view, the ability to form numerous associations between visual cues offered by specific plants and food quality is an important pre-grazing mechanism that helps goats exploit variation in vegetation and graze selectively.

  13. Reliability and concurrent validity of postural asymmetry measurement in adolescent idiopathic scoliosis

    Science.gov (United States)

    Prowse, Ashleigh; Aslaksen, Berit; Kierkegaard, Marie; Furness, James; Gerdhem, Paul; Abbott, Allan

    2017-01-01

    AIM To investigate the reliability and concurrent validity of the Baseline® Body Level/Scoliosis meter for adolescent idiopathic scoliosis postural assessment in three anatomical planes. METHODS This is an observational reliability and concurrent validity study of adolescent referrals to the Orthopaedic department for scoliosis screening at Karolinska University Hospital, Stockholm, Sweden between March-May 2012. A total of 31 adolescents with idiopathic scoliosis (13.6 ± 0.6 years old) of mild-moderate curvatures (25° ± 12°) were consecutively recruited. Measurement of cervical, thoracic and lumbar curvatures, pelvic and shoulder tilt, and axial thoracic rotation (ATR) were performed by two trained physiotherapists in one day. The intraclass correlation coefficient (ICC) was used to determine the inter-examiner reliability (ICC2,1) and the intra-rater reliability (ICC3,3) of the Baseline® Body Level/Scoliosis meter. Spearman’s correlation analyses were used to estimate concurrent validity between the Baseline® Body Level/Scoliosis meter and Gold Standard Cobb angles from radiographs and the Orthopaedic Systems Inc. Scoliometer. RESULTS There was excellent reliability between examiners for thoracic kyphosis (ICC2,1 = 0.94), ATR (ICC2,1 = 0.92) and lumbar lordosis (ICC2,1 = 0.79). There was adequate reliability between examiners for cervical lordosis (ICC2,1 = 0.51), however poor reliability for pelvic and shoulder tilt. Both devices were reproducible in the measurement of ATR when repeated by one examiner (ICC3,3 0.98-1.00). The device had a good correlation with the Scoliometer (rho = 0.78). When compared with Cobb angle from radiographs, there was a moderate correlation for ATR (rho = 0.627). CONCLUSION The Baseline® Body Level/Scoliosis meter provides reliable transverse and sagittal cervical, thoracic and lumbar measurements and valid transverse plan measurements of mild-moderate scoliosis deformity. PMID:28144582

  14. Paclitaxel and carboplatin concurrent with radiotherapy for primary cervical cancer

    NARCIS (Netherlands)

    De Vos, FYFL; Bos, AME; Gietema, JA; Pras, E; Van Der Zee, AGJ; De Vries, EGE; Willemse, PHB

    2004-01-01

    Background: Concurrent radiochemotherapy is currently considered the new standard treatment in locally advanced cervical cancer. Patients and Methods: Eight women with cervical cancer stage IB2-IVA were treated with standard radiation therapy in combination with standard carboplatin (AUC=2, once wee

  15. Unruptured sinus of Valsalva aneurysm presenting with concurrent Morgagni hernia.

    Science.gov (United States)

    Masor, Jonathan J; Davis, S Scott; Chen, Edward P; Henry, Travis S; Book, Wendy M

    2015-10-01

    We describe a patient with dyspnea and intermittent cyanosis who was found to have concurrent right diaphragmatic and right atrial masses, initially thought to have advanced vascular sarcoma. She was ultimately diagnosed with an unruptured sinus of Valsalva aneurysm, a Morgagni hernia, and a patent foramen ovale. Her dyspnea and cyanosis resolved after sequential surgical correction of these defects.

  16. Concurrent Constraint Programming: A Language and Its Execution Model

    Institute of Scientific and Technical Information of China (English)

    廖乐健; 曹元大

    2003-01-01

    To overcome inefficiency in traditional logic programming, a declarative programming language COPS is designed based on the notion of concurrent constraint programming (CCP). The improvement is achieved by the adoption of constraint-based heuristic strategy and the introduction of deterministic components in the framework of CCP. Syntax specification and an operational semantic description are presented.

  17. Hyperlactatemia and concurrent use of antiretroviral therapy among ...

    African Journals Online (AJOL)

    Administrator

    hyperlactatemia and concurrent antiretroviral therapy (ART) use. Methods: A ... We consecutively recruited all eligible HIV infected patients above 18 years admitted on the emergency ward. Data were ... L predicted a 7-fold higher mortality among patients with sepsis. ... National Council of Science and Technology. We.

  18. Selective Impairment of Auditory Selective Attention under Concurrent Cognitive Load

    Science.gov (United States)

    Dittrich, Kerstin; Stahl, Christoph

    2012-01-01

    Load theory predicts that concurrent cognitive load impairs selective attention. For visual stimuli, it has been shown that this impairment can be selective: Distraction was specifically increased when the stimulus material used in the cognitive load task matches that of the selective attention task. Here, we report four experiments that…

  19. A risk analysis model in concurrent engineering product development.

    Science.gov (United States)

    Wu, Desheng Dash; Kefan, Xie; Gang, Chen; Ping, Gui

    2010-09-01

    Concurrent engineering has been widely accepted as a viable strategy for companies to reduce time to market and achieve overall cost savings. This article analyzes various risks and challenges in product development under the concurrent engineering environment. A three-dimensional early warning approach for product development risk management is proposed by integrating graphical evaluation and review technique (GERT) and failure modes and effects analysis (FMEA). Simulation models are created to solve our proposed concurrent engineering product development risk management model. Solutions lead to identification of key risk controlling points. This article demonstrates the value of our approach to risk analysis as a means to monitor various risks typical in the manufacturing sector. This article has three main contributions. First, we establish a conceptual framework to classify various risks in concurrent engineering (CE) product development (PD). Second, we propose use of existing quantitative approaches for PD risk analysis purposes: GERT, FMEA, and product database management (PDM). Based on quantitative tools, we create our approach for risk management of CE PD and discuss solutions of the models. Third, we demonstrate the value of applying our approach using data from a typical Chinese motor company.

  20. Type and Behaviour Reconstruction for Higher-Order Concurrent Programs

    DEFF Research Database (Denmark)

    Amtoft, T.; Nielson, Flemming; Nielson, Hanne Riis

    1997-01-01

    The authors develop a sound and complete type and behaviour inference algorithm for a fragment of CML (Standard ML with primitives for concurrency). Behaviours resemble terms of a process algebra and yield a concise representation of the communications taking place during execution; types...

  1. The Concurrent Development of Spelling Skills in Two Languages

    Science.gov (United States)

    Joy, Rhonda

    2011-01-01

    The study reported on in this paper investigated the concurrent development of spelling in children learning two languages. The study compared over time and between languages the types of spelling errors made in English as a first language and French as a second. Fortyseven grade one English-speaking children completed an English and French…

  2. Concurrent engineering and product models in seafood companies

    DEFF Research Database (Denmark)

    Jonsdottir, Stella; Vesterager, Johan; Børresen, Torger

    1998-01-01

    Concurrent Engineering (CE) can provide an improved approach to product development for extending the lines of seafood products. Information technology (IT) support tools based on product models can provide an integrated and simultaneous approach for specifying new recipes. The seafood industry c...

  3. Concurrent sexual partners-A predictor of Chlamydia

    DEFF Research Database (Denmark)

    Jørgensen, Marianne Johansson; Olesen, Frede; Maindal, Helle Terkildsen

    2013-01-01

    Background:Chlamydia trachomatis is the most common sexually transmitted bacterial infection among young Danes and the spread is highly dependent on the population’s sexual behavior. Previous studies have found concurrent partnerships to be a possible predictor for C. trachomatis, but the signifi......:These preliminary results suggest that concurrent sexual partners is an important predictor for C.trachomatis infections among young Danes aged 15-29. A more concise conclusion will be presented at the Ph.D day......Background:Chlamydia trachomatis is the most common sexually transmitted bacterial infection among young Danes and the spread is highly dependent on the population’s sexual behavior. Previous studies have found concurrent partnerships to be a possible predictor for C. trachomatis......, but the significance of this compared with other well-known predictors has only been briefly described. Aim: The aim is to examine if concurrent partners isan independent predictor for C. trachomatis infection in young Danes aged 15-29 years. Methods: Detailed sexual behavior data were collected via a web...

  4. A graphical Specification Language for Modeling Concurrency based on CSP

    NARCIS (Netherlands)

    Hilderink, Gerald H.; Pascoe, James; Welch, Peter; Loader, Roger; Sunderam, Vaidy

    2002-01-01

    Introduced in this paper is a new graphical modeling language for specifying concurrency in software designs. The language notations are derived from CSP and the resulting designs form CSP diagrams. The notations reflect both data-flow and control-flow aspects, as well as along with CSP algebraic ex

  5. Context Aware Concurrent Execution Framework for Web Browsers

    DEFF Research Database (Denmark)

    Saeed, Aamir; Erbad, Aiman; Olsen, Rasmus Løvenstein

    2016-01-01

    Computing hungry multimedia web applications need to efficiently utilize all the resources of a device. HTML5 web workers is a non-sharing concurrency platform that enables multimedia web application to utilize the available multicore hardware. HTML5 web workers are implemented by major browser...

  6. Reliability and concurrent validity of the Infant Motor Profile

    NARCIS (Netherlands)

    Heineman, Kirsten R.; Middelburg, Karin J.; Bos, Arend F.; Eidhof, Lieke; La Bastide-Van Gemert, Sacha; Van den Heuvel, Edwin R.; Hadders-Algra, Mijna

    2013-01-01

    Aim The Infant Motor Profile (IMP) is a qualitative assessment of motor behaviour in infancy. It consists of five domains: movement variation, variability, fluency, symmetry, and performance. The aim of this study was to assess interobserver reliability and concurrent validity of the IMP with the Al

  7. A graphical Specification Language for Modeling Concurrency based on CSP

    NARCIS (Netherlands)

    Hilderink, G.H.; Pascoe, James; Welch, Peter; Loader, Roger; Sunderam, Vaidy

    2002-01-01

    Introduced in this paper is a new graphical modeling language for specifying concurrency in software designs. The language notations are derived from CSP and the resulting designs form CSP diagrams. The notations reflect both data-flow and control-flow aspects, as well as along with CSP algebraic

  8. Concurrent chemoradiotherapy for locally unresectable head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kohno, Naoyuki; Kitahara, Satoshi; Tamura, Etuyo; Tanabe, Tetuya; Nakanoboh, Manabu; Itoh, Yasuo; Murata, Yasuhiro; Furukawa, Taichi [National Defense Medical Coll., Tokorozawa, Saitama (Japan)

    2000-08-01

    In patients with locally unresectable head and neck cancer with large nodal involvement, the expected five-year survival is as low as 1-2%. To improve the prognosis of these patients, we studied the usefulness of concurrent chemoradiotherapy in a phase 11 trial. Between September 1996 and May 1999, thirty-five patients with locally unresectable head and neck cancer were administered concurrent chemoradiotherapy consisting of low-dose and long-term treatment with cisplatin (CDDP) plus 5-fluorouracil (5FU), or (L-CF); the L-CF regimen consisted of CDDP, 3 mg/m{sup 2} on 5 days of the week and 5FU, 150 mg/m{sup 2} as a 24-hour infunsion on 5 days of the week. Concurrently, conventional radiotherapy was given up to total dose of around 60 Gy. In the 33 patients evaluable for response, 17 complete and 9 partial responses were noted, with an overall response rate of 79%. Oral mucositis and myelosuppression were the major side effects and mucositis was a dose limiting toxicity. This study demonstrates increase in survival among the responders (complete+partial) in the concurrent chemoradiotherapy setting. However 8 local relapses were eventually noted in the 17 complete responders. We concluded that this treatment strategy was beneficial in patients with locally unresectable head and neck cancer. (author)

  9. Investigating the Alignment of Concurrent Design Strategies with Business Strategies

    Directory of Open Access Journals (Sweden)

    Heidar Mirfakhredini

    2013-08-01

    Full Text Available In recent years, managing the interface between design and other activities has received considerable attention. Effective coordination among these areas is therefore vital for effectiveness of the organization. The ideal situation would be continuous interdepartmental contact with well-developed channels of communication. In this study, the best strategy for product design department has been chosen using the strategic formulation framework with fuzzy approach. Subsequently, alignment of each functional design strategy with SAPCO business strategies has been explained. Findings indicate that developing partnerships with global automotive and engineering design companies and building strategic alliances with rival firms to achieve competitive advantages have maximum alignment with business strategies. In addition, findings provide a basis for firms in evaluating the concurrent design strategies and a reference for them to strengthen their concurrent capabilities. There are few reports on sustained use of concurrent design as an on-going strategic process in an organization. This study aims at contributing to the concurrent design solutions.

  10. A Symbolic Approach to Permission Accounting for Concurrent Reasoning

    NARCIS (Netherlands)

    Huisman, Marieke; Mostowski, Wojciech

    2015-01-01

    Permission accounting is fundamental to modular, thread-local reasoning about concurrent programs. This paper presents a new, symbolic system for permission accounting. In existing systems, permissions are numeric value-based and refer to the current thread only. Our system is based on symbolic

  11. The VerCors Tool for Verification of Concurrent Programs

    NARCIS (Netherlands)

    Blom, Stefan; Huisman, Marieke; Jones, Cliff; Pihlajasaari, Pekka; Sun, Jun

    The VerCors tool implements thread-modular static verification of concurrent programs, annotated with functional properties and heap access permissions. The tool supports both generic multithreaded and vector-based programming models. In particular, it can verify multithreaded programs written in

  12. Aging and Concurrent Task Performance: Cognitive Demand and Motor Control

    Science.gov (United States)

    Albinet, Cedric; Tomporowski, Phillip D.; Beasman, Kathryn

    2006-01-01

    A motor task that requires fine control of upper limb movements and a cognitive task that requires executive processing--first performing them separately and then concurrently--was performed by 18 young and 18 older adults. The motor task required participants to tap alternatively on two targets, the sizes of which varied systematically. The…

  13. History-Based Verification of Functional Behaviour of Concurrent Programs

    NARCIS (Netherlands)

    Blom, Stefan; Huisman, Marieke; Zaharieva, M.; Calinescu, Radu; Rumpe, Bernhard

    2015-01-01

    We extend permission-based separation logic with a history-based mechanism to simplify the verification of functional properties in concurrent programs. This allows one to specify the local behaviour of a method intuitively in terms of actions added to a local history; local histories can be combine

  14. Appendicitis Presenting Concurrently with Cecal Arteriovenous Malformation in a Child

    Directory of Open Access Journals (Sweden)

    Sahil P Parikh

    2015-09-01

    Full Text Available Acute appendicitis is a commonly diagnosed surgical problem in the pediatric population. Arterio-venous malformations (AVM of the colonic tract are rarely reported in the pediatric literature. A 13-year old boy who presented with acute appendicitis with concurrent cecal AVM is reported in whom appendectomy was done. Later on radiological investigations AVM was confirmed.

  15. Winning Concurrent Reachability Games Requires Doubly-Exponential Patience

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Koucký, Michal; Miltersen, Peter Bro

    2009-01-01

    We exhibit a deterministic concurrent reachability game PURGATORYn with n non-terminal positions and a binary choice for both players in every position so that any positional strategy for Player 1 achieving the value of the game within given isin < 1/2 must use non-zero behavior probabilities tha...

  16. Threaded Cognition: An Integrated Theory of Concurrent Multitasking

    Science.gov (United States)

    Salvucci, Dario D.; Taatgen, Niels A.

    2008-01-01

    The authors propose the idea of threaded cognition, an integrated theory of concurrent multitasking--that is, performing 2 or more tasks at once. Threaded cognition posits that streams of thought can be represented as threads of processing coordinated by a serial procedural resource and executed across other available resources (e.g., perceptual…

  17. Safe and Verifiable Design of Concurrent Java Programs

    NARCIS (Netherlands)

    Hilderink, G.H.; Welch, P.H.; Bakkers, André; Welch, P.H.; Stiles, G.S.

    2001-01-01

    The design of concurrent programs has a reputation for being difficult, and thus potentially dangerous in safetycritical real-time and embedded systems. The recent appearance of Java, whilst cleaning up many insecure aspects of OO programming endemic in C++, suffers from a deceptively simple threads

  18. The Stay/Switch Model of Concurrent Choice

    Science.gov (United States)

    MacDonall, James S.

    2009-01-01

    This experiment compared descriptions of concurrent choice by the stay/switch model, which says choice is a function of the reinforcers obtained for staying at and for switching from each alternative, and the generalized matching law, which says choice is a function of the total reinforcers obtained at each alternative. For the stay/switch model…

  19. [Valvular surgical treatment concurrent with myocardial revascularization].

    Science.gov (United States)

    Lavítola, P de L; Dallan, L A; Tarasoutchi, F; Grinberg, M; da Luz, P L; Pileggi, F; Jatene, A D

    1992-12-01

    To study the morbidity and mortality due to valvar surgical treatment performed concomitantly to myocardial revascularization. From 1650 patients submitted to mitral or aortic valve surgical treatment, 103 (6.24%) had it associated to myocardial revascularization. Coronary insufficiency was associated to aortic valvar lesion in 66 (64.0%) patients, group I, with mean age of 62.3 +/- 8 years; and in 37 (35.9%) patients with mitral valve lesion, group II, with mean age of 57.8 +/- 5.8 years. Diagnosis was based upon the anamnesis, physical examination and confirmed by cine-coronarographic findings. I-Complications at the immediate postoperative; a) mortality 11 (10.6%) patients, 6 (9.09%) from group I: by low cardiac output 3, uncontrolled arrhythmia 1, mediastinitis 1; acute infarction with cardiogenic shock 1, and 5 (134.5%) of group II: uncontrolled hemorrhage 2, sudden death 1, saphenous vein graft occlusion, respiratory insufficiency and sepsis 2; b) controlled intercurrences that increased the time of hospitalization: mental disorder 5 patients; CVA 7, diabetes decompensation 2, worsening of chronic renal insufficiency 1, upper level digestive hemorrhage 1 and respiratory insufficiency 3 patients. II-late postoperative complications of 77 (83.6%) patients which could be followed up during a period of 60 months: 1) mortality: 3 (3.89%) patients; 2 due to cardiomyopathy and 1 by acute myocardial infarction; 2) late evolution-functional capacity III (NYHA) by cardiomyopathy 6; I/II 68 patients; mild angina 6 patients, 2 underwent revascularization at the end of final 36-42 months. The clinical improvement and mortality indexes statistically similar to the isolate surgical acts stimulate us to keep up with such associate procedures.

  20. Combined versus monotherapy or concurrent therapy for treatment of thalassaemia.

    Science.gov (United States)

    Song, Ta-Shu; Hsieh, Yow-Wen; Peng, Ching-Tien; Chen, Tai-Lin; Lee, Hong-Zin; Chung, Jing-Gung; Hour, Mann-Jen

    2014-01-01

    A combined deferasirox (DFX) and deferiprone (DFP) treatment protocol for relieving thalassemia patients' iron-overload was designed and the pharmacokinetic study was performed by LC-MS/MS. For this open-label, randomized trial, eight patients were recruited and randomly allocated to different treatment regimens: (A) monotherapy with single oral dose of DFX 30 mg/kg, (B) monotherapy with DFP 80 mg/kg/day, twice daily, (C) combined therapy with DFX and DFP (DFX 30 mg/kg for first dose, DFP 40 mg/kg 7 hours later, and DFP 40 mg/kg after another 7 h) and (D) concurrent therapy with DFX 30 mg/kg and DFP 80 mg/kg. Descriptive statistics evaluated pharmacokinetic parameters, AUC0-t, AUC0-inf, Cmax, Tmax, T1/2 and MRT. A positive pharmacokinetic drug interaction was observed in combined therapy. In case of DFX, combined therapy tallied about 2-fold larger than monotherapy in AUC, 1.5-fold larger in Cmax, 1 h longer in Tmax, but 1 h shorter in T1/2. Regarding DFP, most such parameters of combined therapy concurred with monotherapy. Conversely, negative drug interaction was observed in concurrent therapy. With DFX, concurrent therapy attained 1.2- to 2.2-fold lower than monotherapy in AUC0-t and Cmax, 0.6-h shorter in Tmax, and 3-fold longer in T1/2. With DFP, concurrent therapy proved approximately 2-fold larger than monotherapy in AUC and Cmax, 2.5-fold longer in T1/2, and 1.4-fold longer in MRT. Follow-up of subjects' clinical examinations and subjective symptoms showed no adverse events. Our findings showed the combined therapy had advantages, safe, convenient and painless for patients, over the existing concurrent therapy with deferoxamine (DFO) and DFX. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  1. Short- and Long-Term Effects of Concurrent Strength and HIIT Training in Octogenarians with COPD.

    Science.gov (United States)

    Guadalupe-Grau, Amelia; Aznar-Laín, Susana; Mañas, Asier; Castellanos, Juan; Alcázar, Julián; Ara, Ignacio; Mata, Esmeralda; Daimiel, Rosa; García-García, Francisco José

    2017-01-01

    To investigate the short- and long-term effects of concurrent strength and high-intensity interval training (HIIT) on octogenarian COPD patients, nine males (age = 84.2 ± 2.8 years, BMI = 29.3 ± 2.3) with low to severe COPD levels (2.1 ± 1.5 BODE index) underwent a supervised 9-week strength and HIIT exercise program. Training had a significant (p HIIT training increases physical fitness in the oldest-old COPD patients, and has potential long-term benefits.

  2. Polyuria with the Concurrent manifestation of Central Diabetes Insipidus (CDI) & Type 2 Diabetes Mellitus (DM)

    OpenAIRE

    Shin, Hyun-Jong; Kim, Jae-ha; Yi, Joo-Hark; Han, Sang-Woong; Kim, Ho-Jung

    2012-01-01

    We report a rare case of the concurrent manifestation of central diabetes insipidus (CDI) and type 2 diabetes mellitus (DM). A 56 year-old man was diagnosed as a type 2 DM on the basis of hyperglycemia with polyuria and polydipsia at a local clinic two months ago and started an oral hypoglycemic medication, but resulted in no symptomatic improvement at all. Upon admission to the university hospital, the patient's initial fasting blood sugar level was 140 mg/dL, and he showed polydipsic and po...

  3. Irritable bowel syndrome: The incidence of concurrent psychopathology

    Directory of Open Access Journals (Sweden)

    Anita D Stuart

    1999-01-01

    Full Text Available The goal of this study was to improve understanding of the association between physiology and psychology in Functional Gastrointestinal disorders by considering the co-morbidity of lrritable Bowel Syndrome and psychopathology in a sector of the South African population. A comparison was made between the incidence of concurrent psychopathology in a sample of 48 white female patients, aged 25 to 55 years and diagnosed with lrritable Bowel Syndrome and the incidence of psychopathology in a control group that consisted of 39 white women, aged 25 to 55 years, who did not meet the criteria for lrritable Bowel Syndrome.

    The Personality Assessment Inventory was used to determine the incidence of psychopathological personality traits and symptoms in the lrritable Bowel Syndrome group and the control group. This is a selfadministered, objective measuring instrument of adult personality that was developed to provide information about 18 critical clinical variables. The instrument was developed and standardised for use in the clinical assessment of individuals aged 18 years and older. Earlier studies showed a high incidence of associated psychiatric disorder in patients with lrritable Bowel Syndrome. This study confirmed this trend and it seems as if age and level of education has no influence on the incidence of psychopathology in patients with lrritable Bowel Syndrome.

    Opsomming
    Dit was die doel van die studie om 'n verbeterde begrip van die assosiasie tussen fisiologie en sielkunde in Funksionele Maagderm Versteurings te bewerkstellig deur die komorbiditeit van Prikkelbare Dermsindroom en psigopatalogie binne 'n sektor van die Suid Afrikaanse populasie te oorweeg. 'n Vergelyking is getref tussen die voorkoms van konkurrente psigopatalogie in 'n steekproef van 48 wit, vroulike pasiente wat wissel in ouderdomme van 25 tot 55 jaar en gediagnoseer is met Prikkelbare Dermsindroom, en die voorkoms van psigopatalogie in 'n kontrolegroep wat bestaan het

  4. Concurrent Low Brain and High Liver Uptake on FDG PET Are Associated with Cardiovascular Risk Factors

    Science.gov (United States)

    Nam, Hyun-Yeol; Jun, Sungmin; Pak, Kyoungjune

    2017-01-01

    Objective Concurrent low brain and high liver uptake are sometimes observed on fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). We investigated the potential clinical significance of this uptake pattern related to metabolic syndrome (MS). Materials and Methods We retrospectively reviewed data from 264 consecutive males who had undergone general health check-ups, including FDG PET/CT scans. After an overnight fast, the men had their peripheral blood drawn and the levels of various laboratory parameters measured; an FDG PET/CT scan was performed on the same day. We measured the maximum standardized uptake values of the brain and liver from regions of interest manually placed over the frontal cortex at the level of the centrum semiovale and the right lobe of the liver parenchyma, respectively. Results Fasting blood glucose (FBG; odds ratio [OR] = 1.063, p < 0.001) and glycated hemoglobin (HbA1c; OR = 3.634, p = 0.010) were the strongest predictive factors for low brain FDG uptake, whereas waist circumference (OR = 1.200, p < 0.001) and γ-glutamyl transpeptidase (OR = 1.012, p = 0.001) were the strongest predictive factors for high liver uptake. Eleven subjects (4.2%) showed concurrent low brain and high liver FDG uptake, and all but one of these subjects (90.9%) had MS. Systolic blood pressure, waist circumference, FBG, triglyceride, alanine aminotransferase, insulin resistance (measured by homeostasis model assessment), insulin, HbA1c, and body mass index were higher in subjects with this FDG uptake pattern than in those without (all, p < 0.001). Conclusion Concurrent low brain and high liver FDG uptake were closely associated with MS. Moreover, subjects with this pattern had higher values for various cardiovascular risk factors than did those without. PMID:28246520

  5. Concurrent low brain and high liver uptake on FDG PET are associated with cardiovascular risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Hyun Yeol [Dept. of Nuclear Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon (Korea, Republic of); Jun, Sung Min [Dept. of Nuclear Medicine, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan (Korea, Republic of); Pak, Kyoung June; Kim, In Joo [Dept. of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan (Korea, Republic of)

    2017-04-15

    Concurrent low brain and high liver uptake are sometimes observed on fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). We investigated the potential clinical significance of this uptake pattern related to metabolic syndrome (MS). We retrospectively reviewed data from 264 consecutive males who had undergone general health check-ups, including FDG PET/CT scans. After an overnight fast, the men had their peripheral blood drawn and the levels of various laboratory parameters measured; an FDG PET/CT scan was performed on the same day. We measured the maximum standardized uptake values of the brain and liver from regions of interest manually placed over the frontal cortex at the level of the centrum semiovale and the right lobe of the liver parenchyma, respectively. Fasting blood glucose (FBG; odds ratio [OR] = 1.063, p < 0.001) and glycated hemoglobin (HbA1c; OR = 3.634, p = 0.010) were the strongest predictive factors for low brain FDG uptake, whereas waist circumference (OR = 1.200, p < 0.001) and γ-glutamyl transpeptidase (OR = 1.012, p = 0.001) were the strongest predictive factors for high liver uptake. Eleven subjects (4.2%) showed concurrent low brain and high liver FDG uptake, and all but one of these subjects (90.9%) had MS. Systolic blood pressure, waist circumference, FBG, triglyceride, alanine aminotransferase, insulin resistance (measured by homeostasis model assessment), insulin, HbA1c, and body mass index were higher in subjects with this FDG uptake pattern than in those without (all, p < 0.001). Concurrent low brain and high liver FDG uptake were closely associated with MS. Moreover, subjects with this pattern had higher values for various cardiovascular risk factors than did those without.

  6. A familial concurrence of schizophrenia and Gaucher's disease

    Directory of Open Access Journals (Sweden)

    Siomos Konstantinos E

    2007-12-01

    Full Text Available Abstract Background Gaucher's disease (GD is the most frequently encountered lysosomal storage disease. Here, we describe and discuss the observed concurrence of schizophrenia and Gaucher's disease in two siblings. Methods Presentation of a family with two siblings with Gaucher's disease. Results In a six-member family, the first son suffers from schizophrenia, while the third and fourth sons suffer from the Gaucher's disease (type 1 non-neuronopathic. The parents and the second son do not suffer from either illness. Conclusion The concurrence of schizophrenia and Gaucher's disease in the same family is an unusual phenomenon. The literature regarding this coincidence is limited, despite the fact that patients with Gaucher's disease have one or two mutated alleles, considered to be a risk factor leading to conditions such as Dementia, Parkinson's disease and schizophrenia.

  7. Concurrent conditions and human listeriosis, England, 1999-2009.

    Science.gov (United States)

    Mook, Piers; O'Brien, Sarah J; Gillespie, Iain A

    2011-01-01

    The epidemiology of listeriosis in England and Wales changed during 2001-2008; more patients ≥60 years of age had bacteremia than in previous years. To investigate these changes, we calculated risk for listeriosis by concurrent condition for non-pregnancy-associated listeriosis cases reported to the national surveillance system in England during 1999-2009. Conditions occurring with L. monocytogenes infection were coded according to the International Classification of Diseases, 10th Revision, and compared with appropriate hospital episode statistics inpatient denominator data to calculate incidence rates/million consultations. Malignancies (especially of the blood), kidney disease, liver disease, diabetes, alcoholism, and age ≥60 years were associated with an increased risk for listeriosis. Physicians should consider a diagnosis of listeriosis when treating patients who have concurrent conditions. Providing cancer patients, who accounted for one third of cases, with food safety information might help limit additional cases.

  8. Risk Identification and Visualization in a Concurrent Engineering Team Environment

    Science.gov (United States)

    Hihn, Jairus; Chattopadhyay, Debarati; Shishko, Robert

    2010-01-01

    Incorporating risk assessment into the dynamic environment of a concurrent engineering team requires rapid response and adaptation. Generating consistent risk lists with inputs from all the relevant subsystems and presenting the results clearly to the stakeholders in a concurrent engineering environment is difficult because of the speed with which decisions are made. In this paper we describe the various approaches and techniques that have been explored for the point designs of JPL's Team X and the Trade Space Studies of the Rapid Mission Architecture Team. The paper will also focus on the issues of the misuse of categorical and ordinal data that keep arising within current engineering risk approaches and also in the applied risk literature.

  9. Error resilient concurrent video streaming over wireless mesh networks

    Institute of Scientific and Technical Information of China (English)

    LI Dan-jue; ZHANG Qian; CHUAH Chen-nee; YOO Ben S.J.

    2006-01-01

    In this paper, we propose a multi-source multi-path video streaming system for supporting high quality concurrent video-on-demand (VoD) services over wireless mesh networks (WMNs), and leverage forward error correction to enhance the error resilience of the system. By taking wireless interference into consideration, we present a more realistic networking model to capture the characteristics of WMNs and then design a route selection scheme using a joint rate/interference-distortion optimization framework to help the system optimally select concurrent streaming paths. We mathematically formulate such a route selection problem, and solve it heuristically using genetic algorithm. Simulation results demonstrate the effectiveness of our proposed scheme.

  10. An Intensional Concurrent Faithful Encoding of Turing Machines

    Directory of Open Access Journals (Sweden)

    Thomas Given-Wilson

    2014-10-01

    Full Text Available The benchmark for computation is typically given as Turing computability; the ability for a computation to be performed by a Turing Machine. Many languages exploit (indirect encodings of Turing Machines to demonstrate their ability to support arbitrary computation. However, these encodings are usually by simulating the entire Turing Machine within the language, or by encoding a language that does an encoding or simulation itself. This second category is typical for process calculi that show an encoding of lambda-calculus (often with restrictions that in turn simulates a Turing Machine. Such approaches lead to indirect encodings of Turing Machines that are complex, unclear, and only weakly equivalent after computation. This paper presents an approach to encoding Turing Machines into intensional process calculi that is faithful, reduction preserving, and structurally equivalent. The encoding is demonstrated in a simple asymmetric concurrent pattern calculus before generalised to simplify infinite terms, and to show encodings into Concurrent Pattern Calculus and Psi Calculi.

  11. Concurrent Bursty Behavior of Social Sensors in Sporting Events

    CERN Document Server

    Takeichi, Yuki; Suzuki, Reji; Arita, Takaya

    2014-01-01

    The advent of social media expands our ability to transmit information and connect with others instantly, which enables us to behave as "social sensors." Here, we studied concurrent bursty behavior of Twitter users during major sporting events to determine their function as social sensors. We show that the degree of concurrent bursts in tweets (posts) and retweets (re-posts) works as a good indicator of winning or losing a game. More specifically, our tweet analysis of Japanese professional baseball games in 2013 revealed that social sensors can immediately show reactions to positive and negative events through bursts of tweets, but that positive events are more likely to induce a subsequent burst of retweets. These findings were also confirmed in an analysis of the 2014 FIFA World Cup final. We further showed active interactions among social sensors by constructing retweet networks during a baseball game. The resulting networks commonly exhibited user clusters depending on the baseball team, with a scale-fre...

  12. The evolution of the PVM concurrent computing system

    Energy Technology Data Exchange (ETDEWEB)

    Giest, G.A. [Oak Ridge National Lab., TN (United States); Sunderam, V.S. [Emory Univ., Atlanta, GA (United States). Dept. of Mathematics and Computer Science

    1993-07-01

    Concurrent and distributed computing, using portable software systems or environments on general purpose networked computing platforms, has recently gained widespread attention. Many such systems have been developed, and several are in production use. This paper describes the evolution of the PVM system, a software infrastructure for concurrent computing in networked environments. PVM has evolved over the past years; it is currently in use at several hundred institutions worldwide for applications ranging from scientific supercomputing to high performance computations in medicine, discrete mathematics, and databases, and for learning parallel programming. We describe the historical evolution of the PVM system, outline the programming model and supported features, present results gained from its use, list representative applications from a variety of disciplines that PVM has been used for, and comment on future trends and ongoing research projects.

  13. Proceedings 8th International Workshop on Security Issues in Concurrency

    CERN Document Server

    Chatzikokolakis, Konstantinos; 10.4204/EPTCS.51

    2011-01-01

    This volume contains the proceedings of the 8th Workshop on Security Issues in Concurrency (SecCo 2010). The workshop was held in Paris, France on August 30th, 2010, as a satellite workshop of CONCUR'10. The aim of the SecCo workshop series is to cover the gap between the security and the concurrency communities. More precisely, the workshop promotes the exchange of ideas, trying to focus on common interests and stimulating discussions on central research questions. In particular, we called for papers dealing with security issues (such as authentication, integrity, privacy, confidentiality, access control, denial of service, service availability, safety aspects, fault tolerance, trust, language-based security, probabilistic and information theoretic models) in emerging fields like web services, mobile ad-hoc networks, agent-based infrastructures, peer-to-peer systems, context-aware computing, global/ubiquitous/pervasive computing.

  14. Proceedings 7th International Workshop on Security Issues in Concurrency

    CERN Document Server

    Boreale, Michele; 10.4204/EPTCS.7

    2009-01-01

    This volume contains the proceedings of the 7th Workshop on Security Issues in Concurrency (SecCo'09). The workshop was held in Bologna, Italy on September 5th 2009, as a satellite workshop of CONCUR'09. The aim of the SecCo workshop series is to cover the gap between the security and the concurrency communities. More precisely, the workshop promotes the exchange of ideas, trying to focus on common interests and stimulating discussions on central research questions. In particular, we called for papers dealing with security issues (such as authentication, integrity, privacy, confidentiality, access control, denial of service, service availability, safety aspects, fault tolerance, trust, language-based security, probabilistic and information theoretic models) in emerging fields like web services, mobile ad-hoc networks, agent-based infrastructures, peer-to-peer systems, context-aware computing, global/ubiquitous/pervasive computing.

  15. Separative power of an optimised concurrent gas centrifuge

    CERN Document Server

    Bogovalov, S V

    2015-01-01

    The problem of separation of uranium isotopes in a concurrent gas centrifuge is solved analytically. Separative power of the optimized concurrent gas centrifuges equals to $\\delta U=12.7(V/700~{\\rm m/s})^2 (300 ~{\\rm K}/T)L, ~{\\rm kg ~SWU/yr}$, where $L$ and $V$ are the length and linear velocity of the rotor of the gas centrifuge, $T$ is the temperature. This formula well agrees with an empirical separative power of counter current gas centrifuges. The optimal value of the separative power is not unique on the plane $(p_w,v_z)$, where $p_w$ is pressure at the wall of the rotor and $v_z$ is axial velocity of the gas. This value is constant on a line defined by the equation $p_wv_z=constant$. Equations defining the mass flux and the electric power necessary to support the rotation of the gas centrifuge are obtained.

  16. Engineering Bereitschaft as an enabler for Concurrent Engineering

    DEFF Research Database (Denmark)

    Christiansen, Kåre; Vesterager, Johan

    1999-01-01

    will describe experience from a shipyard where an object oriented product model of a double hull supertanker and a product configurator prototype have been developed as part of an industrial Ph.D.-project. Configuration of the steel structures in a ship and the succeeding producability evaluation can......Industrial companies observe a general trend towards more customised products and shorter product life cycles. Furthermore, the market demands shorter lead-time and high-quality products at a competitive price. Concurrent Engineering address these challenges. Product modelling is a key aspect...... of the Concurrent Engineering literature. One problem with the product modelling literature is that it tends to assume that product development is revolutionary. Very often product development is evolutionary and it means that product modelling should have a major emphasis on reuse. In this paper it is suggested...

  17. Automating Fine Concurrency Control in Object-Oriented Databases

    CERN Document Server

    Malta, Carmelo; 10.1109/ICDE.1993.344057

    2010-01-01

    Several propositions were done to provide adapted concurrency control to object-oriented databases. However, most of these proposals miss the fact that considering solely read and write access modes on instances may lead to less parallelism than in relational databases! This paper cope with that issue, and advantages are numerous: (1) commutativity of methods is determined a priori and automatically by the compiler, without measurable overhead, (2) run-time checking of commutativity is as efficient as for compatibility, (3) inverse operations need not be specified for recovery, (4) this scheme does not preclude more sophisticated approaches, and, last but not least, (5) relational and object-oriented concurrency control schemes with read and write access modes are subsumed under this proposition.

  18. Construct and concurrent validity of the Korean Career Indecision Inventory.

    Science.gov (United States)

    Tak, Jinkook

    2006-04-01

    Construct and concurrent validity of the Korean Career Indecision Inventory were examined. Data were collected from 238 South Korean college students. A confirmatory factor analysis supported the original five-factor model. As hypothesized, scores were significantly correlated with various variables such as scores on the Korean versions of the Career Decision Scale (r =.49), the Vocational Identity Scale in My Vocational Situation (r=-.63), the Career Decision-making Self-efficacy Scale (r=-.47), and Negative Affectivity (r=.37). These results support construct validity inventory. Students who indicated they were undecided about their careers had significantly higher scores than those who indicated they had decided on a career, supporting concurrent validity. Implications and limitations are discussed.

  19. Secondary Syphilis With Hepatitis and Nephrotic Syndrome: A Rare Concurrence.

    Science.gov (United States)

    Makker, Jasbir; Bajantri, Bharat; Nayudu, Suresh Kumar

    2016-07-01

    Syphilis, a chronic multisystem disease, is caused by a spirochete, Treponema pallidum. Clinical presentation may expand to several stages including primary, secondary and latent syphilis, which may present as early or late syphilis. Nephrotic syndrome and acute hepatitis are well-known complications of secondary syphilis. To the best of our knowledge, secondary syphilis with coexisting renal and hepatic complications has rarely been reported. Here we present a rare case of concurrent nephrotic syndrome and acute hepatitis in a patient with secondary syphilis.

  20. CONCURRENT PRODUCT PORTFOLIO PLANNING AND MIXED PRODUCT ASSEMBLY LINE BALANCING

    Institute of Scientific and Technical Information of China (English)

    BRYAN April; HU S Jack; KOREN Yoram

    2007-01-01

    Reconfigurable products and manufacturing systems have enabled manufacturers to provide "cost effective" variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to supply all the possible variants to the market for some industries. Therefore, the determination of the right number of product variants to offer in the product portfolios becomes an important consideration. The product portfolio planning problem had been independently well studied from marketing and engineering perspectives. However, advantages can be gained from using a concurrent marketing and engineering approach. Concurrent product development strategies specifically for reconfigurable products and manufacturing systems can allow manufacturers to select best product portfolios from marketing, product design and manufacturing perspectives. A methodology for the concurrent design of a product portfolio and assembly system is presented. The objective of the concurrent product portfolio planning and assembly system design problem is to obtain the product variants that will make up the product portfolio such that oversupply of optional modules is minimized and the assembly line efficiency is maximized. Explicit design of the assembly system is obtained during the solution of the problem. It is assumed that the demand for optional modules and the assembly times for these modules are known a priori. A genetic algorithm is used in the solution of the problem. The basic premise of this methodology is that the selected product portfolio has a significant impact on the solution of the assembly line balancing problem. An example is used to validate this hypothesis. The example is then further developed to demonstrate how the methodology can be used to obtain the optimal product portfolio. This approach is intended for use by manufacturers during the early design stages of product family design.

  1. Performance of humans in concurrent avoidance/positive-reinforcement schedules

    OpenAIRE

    Ruddle, H. V.; Bradshaw, C M; Szabadi, E; Foster, T M

    1982-01-01

    Performance maintained under concurrent schedules consisting of a variable-interval avoidance component and a variable-interval positive-reinforcement component was studied in three human subjects using points exchangeable for money as the reinforcer. The rate of responding in the avoidance component increased, and the rate of responding in the positive-reinforcement component declined, as a function of the frequency of point-losses avoided in the avoidance component. The performance of all t...

  2. TUBERCULAR MENINGITIS WITH CONCURRENT INTRACRANIAL AND INTRA-SPINAL TUBERCULOMAS

    OpenAIRE

    2015-01-01

    K.S.Hegde Medical Academy, Departments of Medicine, Neurosurgery, Pathology and Radiology, Mangalore, Karnataka, India Central nervous system (CNS) tuberculosis commonly manifests as tubercular meningitis CNS tuberculomas are more common intracranially and less frequently involve the spinal cord. We report an unusual case of CNS tuberculosis presented with predominant features of tubercular meningitis with concurrent intra-cranial and intra-medullary tuberculomas in any evidence of pulm...

  3. Scleromyxedema concurrent with dermatomyositis and paraproteinemia: A case report

    OpenAIRE

    M N Starovoitova; O V Desinova; Guseva, N. G.

    2015-01-01

    The paper describes the case of a female patient who had at least three diseases: scleromyxedema, dermatomyositis/polymyositis (DM/PM), and paraproteinemia (monoclonal gammopathy). The concurrence of these diseases determines the atypism of their clinical and morphological patterns, as well as refractoriness to performed therapy. Scleromyxedema preceded DM followed by paraproteinemia, which does not rule out its presence in an earlier period when the patent was not carefully examined. The spe...

  4. Petri net model for analysis of concurrently processed complex algorithms

    Science.gov (United States)

    Stoughton, John W.; Mielke, Roland R.

    1986-01-01

    This paper presents a Petri-net model suitable for analyzing the concurrent processing of computationally complex algorithms. The decomposed operations are to be processed in a multiple processor, data driven architecture. Of particular interest is the application of the model to both the description of the data/control flow of a particular algorithm, and to the general specification of the data driven architecture. A candidate architecture is also presented.

  5. Cooperative Planning, Uncertainty, and Managerial Control in Concurrent Design

    OpenAIRE

    Victoria L. Mitchell; Barrie R. Nault

    2007-01-01

    We examine whether cooperative planning and uncertainty affect the magnitude of rework in concurrent engineering projects with upstream and downstream operations, and explore the impact of such rework on project delays. Using survey data from a sample of 120 business process (BP) redesign and related information technology (IT) development projects in healthcare and telecommunications, our results indicate that upstream (BP) rework and downstream (IT) rework is mediated and mitigated by coope...

  6. Concurrent adversities among adolescents with conduct problems: the NAAHS study.

    Science.gov (United States)

    Reigstad, Bjørn; Kvernmo, Siv

    2016-10-01

    Several studies have confirmed that maltreatment and abuse in childhood are related to conduct problems. Less is known about such relationships with concurrent adversities in adolescence and, also, when compared with other severe adversities and possible multiple additive effects. The study encompassed a community population of 4881 adolescents 15-16 years of age 50.1 % boys and 49.9 % girls. Youth with and without conduct problem scores within the deviant range on the Strength and Difficulties Questionnaire (SDQ) was compared on 12 concurrent adversities. Based on self-reports, 4.4 % of the adolescents had conduct problem scores within the deviant range and more girls (5.1 %) than boys (3.7 %). In the deviant conduct problem group, 65.1 % had experienced two or more concurrent adversities compared with 26.3 % of youths in the non-deviant group (OR 5.23, 95 % CI 3.91-7.01). Likewise, the deviant conduct problem group was from 1.71 to 8.43 times more at the risk of experiencing the different adversities. Parental mental health problems and experiences of violence were multivariately strongest associated with conduct problem scores within the deviant range on the SDQ. A strong multiple additive relationship with adversities was found. Two-thirds of youth with SDQ conduct problem scores within the deviant range reported two or more concurrent adversities. Clinicians should seek information about kinds and amount of possible traumatic adversities in youth with conduct problems and offer evidence based treatment.

  7. Concurrence of Juvenile Idiopathic Arthritis and Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Ben Abdelghani Kaouther

    2011-01-01

    Full Text Available We report a 21-year-old female patient known to have Juvenile idiopathic arthritis (JIA who later developed multiple sclerosis (MS. The disease was documented on the brain and cerebral magnetic resonance imaging (MRI and the visual evoked potential. Our case emphasizes the need to evaluate the symptoms and brain MRI carefully. The concurrence of MS and JIA is uncommon. The possible relationship between the 2 diseases was discussed.

  8. Cauldrons: An Abstraction for Concurrent Problems Solving. Revision.

    Science.gov (United States)

    1986-09-01

    PROGRAM ELEMENT. PROJECT. TASK Artificial Inteligence Laboratory ARtA G WORK UNIT NUMVERS S 545 Technology Square etJ Cambridge, MA 02139 TIM II...D-11194 12611 CAU1,LDRONS: AN ROSTRACTION FOR CONCURRENT PROBLEMS1/ RSOLVING REYISION(U) MASSACHUSETTS INST OF TECHCANIRIDGE ARTIFICIAL INTELLIGENCE...is described, accompanied by cxanmple of their application to various domains. ’lhis report describes research done at both the MIT Artificial

  9. Concurrent Programming Using Actors: Exploiting Large-Scale Parallelism,

    Science.gov (United States)

    1985-10-07

    ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK* Artificial Inteligence Laboratory AREA Is WORK UNIT NUMBERS 545 Technology Square...D-R162 422 CONCURRENT PROGRMMIZNG USING f"OS XL?ITP TEH l’ LARGE-SCALE PARALLELISH(U) NASI AC E Al CAMBRIDGE ARTIFICIAL INTELLIGENCE L. G AGHA ET AL...RESOLUTION TEST CHART N~ATIONAL BUREAU OF STANDA.RDS - -96 A -E. __ _ __ __’ .,*- - -- •. - MASSACHUSETTS INSTITUTE OF TECHNOLOGY ARTIFICIAL

  10. Sparsest cuts and concurrent flows in product graphs

    NARCIS (Netherlands)

    Bonsma, Paul

    2004-01-01

    A cut [S.S] is a sparsest cut of a graph G if its cut value [S][S]/[S.S] is maximum (this is the reciprocal of the well-known edge-density of the cut). In the (undirected) uniform concurrent flow problem on G, between every vertex pair of G flow paths with a total flow of 1 have to be established. T

  11. Quasi serializable concurrency control in mobile broadcast environments

    Institute of Scientific and Technical Information of China (English)

    Dang Depeng; Liu Yunsheng

    2007-01-01

    The problem of maintaining data consistency in mobile broadcast environments is researched.Quasi serializability is formally defined and analyzed at first.It was shown that quasi serializability is less stringent than serializability when database consistency is maintained for transactions.Then,corresponding concurrency control protocol that supports both update transactions and read-only transactions is outlined for mobile broadcast environments.Finally,the simulation results confirmed that the proposed protocol could improve the response time significantly.

  12. CONCURRENT SPEECHES SEPARATION USING WRAPPED DISCRETE FOURIER TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    Zhang Xichun; Li Yunjie; Zhang Jun; Wei Gang

    2005-01-01

    This letter proposes a new method for concurrent voiced speech separation. Firstly the Wrapped Discrete Fourier Transform (WDFT) is used to decompose the harmonic spectra of the mixed speeches. Then the individual speech is reconstructed by using the sinusoidal speech model. By taking advantage of the non-uniform frequency resolution of WDFT, harmonic spectra parameters can be estimated and separated accurately. Experimental results on mixed vowels separation show that the proposed method can recover the original speeches effectively.

  13. Cutaneous xanthomas with concurrent demodicosis and dermatophytosis in a cat.

    Science.gov (United States)

    Vogelnest, L J

    2001-07-01

    Multiple cutaneous xanthomas, associated with fasting hyperlipidaemia, are described in a 9-month-old domestic long-haired cat. A severely pruritic, papular, and crusting dermatitis affecting the head and neck, initially diagnosed as lesions of the eosinophilic granuloma complex, progressively developed on the head and pinnae. Pruritus was controlled with administration of prednisolone and chlorambucil. Repeat histological examination confirmed the diagnosis of cutaneous xanthoma and concurrent mild demodicosis. Marked fasting hypercholesterolaemia, hypertriglyceridaemia and transient hyperglycaemia were subsequently confirmed. Treatment for hyperlipidaemia and xanthomas with a low-fat diet (Hill's Feline r/d) and the previously unreported treatment for feline demodicosis of daily oral milbemycin were commenced. Multiple pink, alopecic plaques and papules gradually regressed, however pruritus recurred if immunosuppressive treatment was reduced, and well-demarcated areas of alopecia developed on the head, limbs and trunk, despite negative skin scrapings for demodex mites. Fungal culture of hair samples yielded Microsporum canis. All cutaneous lesions resolved with the addition of griseofulvin to the treatment regimen. Concurrent corneal ulceration and keratoconjunctivitis sicca ultimately resolved with treatment, including topical cyclosporin. Diabetes mellitus developed 6 months after resolution of skin lesions. No cutaneous or ocular abnormalities were present 6 months later with continued low-fat diet and insulin administration, although transient recurrence of papules and pruritus occurred after inadvertent access to a fatty meal. An underlying primary hyperlipidaemia was suspected, causing pruritic xanthomas. This may represent the first report of concurrent cutaneous xanthomas, demodicosis and dermatophytosis in a cat.

  14. Concurrent infection of Japanese encephalitis and mixed plasmodium infection

    Directory of Open Access Journals (Sweden)

    Girish Chandra Bhatt

    2012-01-01

    Full Text Available Japanese encephalitis (JE and malaria would coexist in the areas where both illnesses are endemic with overlapping clinical pictures, especially in a case of febrile encephalopathy with hepatosplenomegaly. However, there are no published data till date showing concurrent infection of these two agents despite both diseases being coendemic in many areas. We report a case of concurrent infection of JE and mixed plasmodium infection, where the case, initially diagnosed as cerebral malaria did not improve on antimalarials and alternative diagnosis of JEV encephalitis was thought which was confirmed by a serological test. To the best of our knowledge, this is the first case report of concurrent Japanese encephalitis with mixed plasmodium infection. We report a case of 3-year-old male child, who presented with febrile encephalopathy with hepatosplenomegaly. Based on a rapid diagnostic test and peripheral smear examination, a diagnosis of mixed P.Vivax and P.falciparum infection was made and the patient was treated with quinine and doxycycline. However, besides giving antimalarials the patient did not improve and an alternative diagnosis of JE was considered as the patient was from the endemic zone of Japanese encephalitis. Cerebrospinal fluid (CSF of the patient was sent for a virological study which came out to be positive for JE IgM in CSF, which is confirmatory of JE infection. In a patient with febrile encephalopathy with hepatosplenomegaly especially in areas coendemic for JE and malaria, the possibility of mixed infection should be kept in mind.

  15. Interactive state-space analysis of concurrent systems

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, E.T.; Razouk, R.R.

    1987-10-01

    The introduction of concurrency into programs has added to the complexity of the software design process. This is most evident in the design of communications protocols where concurrency is inherent to the behavior of the system. The complexity exhibited by such software systems makes more evident the need for computer-aided tools for automatically analyzing behavior. The Distributed Systems project at UCI has been developing techniques and tools, based on Petri nets, which support the design and evaluation of concurrent software systems. Techniques based on constructing reachability graphs that represent projections and selections of complete state-spaces have been developed. This paper focuses attention on the computer-aided analysis of these graphs for the purpose of proving correctness of the modeled system. The application of the analysis technique to evaluating simulation results for correctness is discussed. The tool which supports this analysis (the reachability graph analyzer, RGA) is also described. This tool provides mechanisms for proving general system properties (e.g., deadlock-freeness) as well as system-specific properties. The tool is sufficiently general to allow a user to apply complex user-defined analysis algorithms to reachability graphs. The alternating-bit protocol, with a bounded channel, is used to demonstrate the power of the tool and to point to future extensions.

  16. Teaching Formal Models of Concurrency Specification and Analysis

    Directory of Open Access Journals (Sweden)

    N. V. Shilov

    2015-01-01

    Full Text Available There is a widespread and rapidly growing interest to the parallel programming nowadays. This interest is based on availability of supercomputers, computer clusters and powerful graphic processors for computational mathematics and simulation. MPI, OpenMP, CUDA and other technologies provide opportunity to write C and FORTRAN code for parallel speed-up of execution without races for resources. Nevertheless concurrency issues (like races are still very important for parallel systems in general and distributed systems in particular. Due to this reason, there is a need of research, study and teaching of formal models of concurrency and methods of distributed system verification.The paper presents an individual experience with teaching Formal Models of Concurrency as a graduate elective course for students specializing in high-performance computing. First it sketches course background, objectives, lecture plan and topics. Then the paper presents how to formalize (i.e. specify a reachability puzzle in semantic, syntactic and logic formal models, namely: in Petri nets, in a dialect of Calculus of Communicating Systems (CCS and in Computation Tree Logic (CTL. This puzzle is a good educational example to present specifics of different formal notations.The article is published in the author’s wording.

  17. Retroactive Streaming Fails to Improve Concurrent Vowel Identification.

    Science.gov (United States)

    Brandewie, Eugene J; Oxenham, Andrew J

    2015-01-01

    The sequential organization of sound over time can interact with the concurrent organization of sounds across frequency. Previous studies using simple acoustic stimuli have suggested that sequential streaming cues can retroactively affect the perceptual organization of sounds that have already occurred. It is unknown whether such effects generalize to the perception of speech sounds. Listeners' ability to identify two simultaneously presented vowels was measured in the following conditions: no context, a preceding context stream (precursors), and a following context stream (postcursors). The context stream was comprised of brief repetitions of one of the two vowels, and the primary measure of performance was listeners' ability to identify the other vowel. Results in the precursor condition showed a significant advantage for the identification of the second vowel compared to the no-context condition, suggesting that sequential grouping mechanisms aided the segregation of the concurrent vowels, in agreement with previous work. However, performance in the postcursor condition was significantly worse compared to the no-context condition, providing no evidence for an effect of stream segregation, and suggesting a possible interference effect. Two additional experiments involving inharmonic (jittered) vowels were performed to provide additional cues to aid retroactive stream segregation; however, neither manipulation enabled listeners to improve their identification of the target vowel. Taken together with earlier studies, the results suggest that retroactive streaming may require large spectral differences between concurrent sources and thus may not provide a robust segregation cue for natural broadband sounds such as speech.

  18. Retroactive Streaming Fails to Improve Concurrent Vowel Identification.

    Directory of Open Access Journals (Sweden)

    Eugene J Brandewie

    Full Text Available The sequential organization of sound over time can interact with the concurrent organization of sounds across frequency. Previous studies using simple acoustic stimuli have suggested that sequential streaming cues can retroactively affect the perceptual organization of sounds that have already occurred. It is unknown whether such effects generalize to the perception of speech sounds. Listeners' ability to identify two simultaneously presented vowels was measured in the following conditions: no context, a preceding context stream (precursors, and a following context stream (postcursors. The context stream was comprised of brief repetitions of one of the two vowels, and the primary measure of performance was listeners' ability to identify the other vowel. Results in the precursor condition showed a significant advantage for the identification of the second vowel compared to the no-context condition, suggesting that sequential grouping mechanisms aided the segregation of the concurrent vowels, in agreement with previous work. However, performance in the postcursor condition was significantly worse compared to the no-context condition, providing no evidence for an effect of stream segregation, and suggesting a possible interference effect. Two additional experiments involving inharmonic (jittered vowels were performed to provide additional cues to aid retroactive stream segregation; however, neither manipulation enabled listeners to improve their identification of the target vowel. Taken together with earlier studies, the results suggest that retroactive streaming may require large spectral differences between concurrent sources and thus may not provide a robust segregation cue for natural broadband sounds such as speech.

  19. Retroactive Streaming Fails to Improve Concurrent Vowel Identification

    Science.gov (United States)

    2015-01-01

    The sequential organization of sound over time can interact with the concurrent organization of sounds across frequency. Previous studies using simple acoustic stimuli have suggested that sequential streaming cues can retroactively affect the perceptual organization of sounds that have already occurred. It is unknown whether such effects generalize to the perception of speech sounds. Listeners’ ability to identify two simultaneously presented vowels was measured in the following conditions: no context, a preceding context stream (precursors), and a following context stream (postcursors). The context stream was comprised of brief repetitions of one of the two vowels, and the primary measure of performance was listeners’ ability to identify the other vowel. Results in the precursor condition showed a significant advantage for the identification of the second vowel compared to the no-context condition, suggesting that sequential grouping mechanisms aided the segregation of the concurrent vowels, in agreement with previous work. However, performance in the postcursor condition was significantly worse compared to the no-context condition, providing no evidence for an effect of stream segregation, and suggesting a possible interference effect. Two additional experiments involving inharmonic (jittered) vowels were performed to provide additional cues to aid retroactive stream segregation; however, neither manipulation enabled listeners to improve their identification of the target vowel. Taken together with earlier studies, the results suggest that retroactive streaming may require large spectral differences between concurrent sources and thus may not provide a robust segregation cue for natural broadband sounds such as speech. PMID:26451598

  20. Concurrent dengue and malaria in an area in Kolkata

    Institute of Scientific and Technical Information of China (English)

    Amiya Kumar Hati; Indranil Bhattacharjee; Hiranmoy Mukherjee; Bhaswati Bandyopadhayay; Deban Bandyopadhyay; Rajyasree De; Goutam Chandra

    2012-01-01

    ABSTRACT Objective:To establish the nature and extent of dual dengue and malaria infections in an endemic area through a longitudinal study.Methods: A prospective study was conducted from August2005to December2010to document the nature and extent of concurrent dengue and malaria infections in an area in central Kolkata, endemic both for dengue and malaria.Results:Of2 971 suspected cases of dengue fever, in605 (20.36%)persons dengue infection was detected, of whom46 (7.60%, 46/605)patients (40 and6suffered from secondary and primary dengue fever respectively) were simultaneously suffering from malaria (28 and18 were infected with Plasmodium vivax (P.vivax) andPlasmodium falciparum (P. falciparum) respectively, such dual infections of dengue and malaria were detected in all the years of the study period, except 2007, indicating intense transmission of both dengue and malaria in the study area, and the phenomenon was not an isolated one, the rate of concomitant infections ranged from25% in2009 to4.9% in 2005. Out of total population surveyed,1.54% (46/2 971)had concurrent dengue and malaria infection.Conclusions: These findings added a new dimension in diagnosis, treatment, epidemiology and control of dengue and malaria. The possible risk of concurrent dengue and malaria infections should always be kept in mind in endemic areas for early diagnosis employing modern technology and prompt and effective treatment to avoid serious complications.

  1. Programming Models for Concurrency and Real-Time

    Science.gov (United States)

    Vitek, Jan

    Modern real-time applications are increasingly large, complex and concurrent systems which must meet stringent performance and predictability requirements. Programming those systems require fundamental advances in programming languages and runtime systems. This talk presents our work on Flexotasks, a programming model for concurrent, real-time systems inspired by stream-processing and concurrent active objects. Some of the key innovations in Flexotasks are that it support both real-time garbage collection and region-based memory with an ownership type system for static safety. Communication between tasks is performed by channels with a linear type discipline to avoid copying messages, and by a non-blocking transactional memory facility. We have evaluated our model empirically within two distinct implementations, one based on Purdue’s Ovm research virtual machine framework and the other on Websphere, IBM’s production real-time virtual machine. We have written a number of small programs, as well as a 30 KLOC avionics collision detector application. We show that Flexotasks are capable of executing periodic threads at 10 KHz with a standard deviation of 1.2us and have performance competitive with hand coded C programs.

  2. Concurrent Use of Cigarettes and Smokeless Tobacco in Minnesota

    Directory of Open Access Journals (Sweden)

    Raymond G. Boyle

    2012-01-01

    Full Text Available Cigarette smokers are being encouraged to use smokeless tobacco (SLT in locations where smoking is banned. We examined state-wide data from Minnesota to measure changes over time in the use of SLT and concurrent use of cigarettes and SLT. The Minnesota Adult Tobacco Survey was conducted four times between 1999 and 2010 and has provided state-wide estimates of cigarette smoking, SLT use and concurrent use of SLT by smokers. The prevalence of SLT was essentially unchanged through 2007, then increased significantly between 2007 and 2010 (3.1% versus 4.3%, P<0.05. Similarly, the prevalence of cigarette smokers who reported using SLT was stable then increased between 2007 and 2010 (4.4% versus 9.6%, P<0.05. The finding of higher SLT use by smokers could indicate that smokers in Minnesota are in an experimental phase of testing alternative products as they adjust to recent public policies restricting smoking in public places. The findings are suggestive that some Minnesota smokers are switching to concurrent use of cigarettes and SLT. Future surveillance reports will be necessary to confirm the results.

  3. Product design for energy reduction in concurrent engineering: An Inverted Pyramid Approach

    Science.gov (United States)

    Alkadi, Nasr M.

    on product, process, and system design parameters. In depth evaluation to how the design and manufacturing normally happen in concurrent engineering provided a framework to develop energy system levels in machining within the concurrent engineering environment using the method of "Inverted Pyramid Approach", (IPA). The IPA features varying levels of output energy based information depending on the input design parameters that is available during each stage (level) of the product design. The experimental work, the in-depth evaluation of design and manufacturing in CE, and the developed energy system levels in machining provided a solid base for the development of the model for the design for energy reduction in CE. The model was used to analyze an example part where 12 evolving designs were thoroughly reviewed to investigate the sensitivity of energy to design parameters in machining. The model allowed product design teams to address manufacturing energy concerns early during the design stage. As a result, ranges for energy sensitive design parameters impacting product manufacturing energy consumption were found in earlier levels. As designer proceeds to deeper levels in the model, this range tightens and results in significant energy reductions.

  4. Bacterial flora concurrent with Helicobacter pylori in the stomach of patients with upper gastrointestinal diseases

    Institute of Scientific and Technical Information of China (English)

    Yuan Hu; Li-Hua He; Di Xiao; Guo-Dong Liu; Yi-Xin Gu; Xiao-Xia Tao; Jian-Zhong Zhang

    2012-01-01

    AIM:To investigate the non-Helicobacter pylori (H.pylorl) bacterial flora concurrent with H.py/ori infection.METHODS:A total of 103 gastric biopsy specimens from H.py/ori positive patients were selected for bacterial culture.All the non-H.py/ori bacterial isolates were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS).RESULTS:A total of 201 non-H.py/ori bacterial isolates were cultivated from 67 (65.0%) of the 103 gastric samples,including 153 isolates identified successfully at species level and 48 at genus level by MALDI-TOF MS.The dominant species were Streptococcus,Neisseria,Rothia and Staphylococcus,which differed from the predominantly acid resistant species reported previously in healthy volunteers.The prevalence of non-H.pylori bacteria was higher in non-ulcer dyspepsia group than in gastric ulcer group (100% vs 42.9%,P < 0.001).Six bacterial species with urease activity (Staphylococcus epidermidis,Staphylococcus warneri,Staphylococcus capitis,Staphylococcus aureus,Brevibacterium spp.and Klebsiella pneumoniae) were also isolated.CONCLUSION:There is a high prevalence of the non-H.pylori bacteria concurrent with H.pylori infection,and the non-H.pylori bacteria may also play important as-yet-undiscovered roles in the pathogenesis of stomach disorders.

  5. The effects of concurrent cognitive tasks on postural sway in healthy subjects

    Directory of Open Access Journals (Sweden)

    Banu Mujdeci

    2016-02-01

    Full Text Available ABSTRACT INTRODUCTION: Keeping balance of the upright stance is a highly practiced daily task for healthy adults and is effectively performed without overt attentional control in most. OBJECTIVE: The purpose of this study was to examine the influence of concurrent cognitive tasks on postural sway in healthy participants. METHODS: This was a prospective study. 20 healthy volunteer subjects were included. The cognitive and balance tasks were performed separately and then, concurrently. Postural control task consisted of 6 conditions (C of the Sensory Organization Test. The cognitive task consisted of digit rehearsal task of varying presentation and varying levels of difficulty. RESULTS: A statistically significant difference was noted between dual task and no task for C1, C2, C3 and C4 Sensory Organization Test scores ( p 0.05. CONCLUSION: During dual task, increase has been determined in postural sway for C1, C2, C3 and C4 for all presentation modes and difficulty levels of the cognitive tasks.

  6. Java并发系统的ACP模型%ACP Model of Java Concurrency

    Institute of Scientific and Technical Information of China (English)

    刘园; 徐宝文

    2003-01-01

    Feasibility and efficiency of analyzing concurrent programs mostly rely on the programs′ representations.This paper proposes a model of Java concurrent system by using ACP,so that Java concurrent system can be trans-formed to process algebra expressions which facilitate model checking or some further analysis.

  7. 7 CFR 1610.6 - Concurrent Bank and RUS cost-of-money loans.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Concurrent Bank and RUS cost-of-money loans. 1610.6..., DEPARTMENT OF AGRICULTURE LOAN POLICIES § 1610.6 Concurrent Bank and RUS cost-of-money loans. (a) The Bank makes loans, under section 408 of the Act, concurrently with RUS cost-of-money loans made under section...

  8. VerCors: A Layered Approach to Practical Verification of Concurrent Software

    NARCIS (Netherlands)

    Amighi, A.; Blom, Stefan; Huisman, Marieke

    This paper discusses how several concurrent program verification techniques can be combined in a layered approach, where each layer is especially suited to verify one aspect of concurrent programs, thus making verification of concurrent programs practical. At the bottom layer, we use a combination

  9. Strength and Conditioning and Concurrent Training Practices in Elite Rugby Union.

    Science.gov (United States)

    Jones, Thomas W; Smith, Andrew; Macnaughton, Lindsay S; French, Duncan N

    2016-12-01

    Jones, TW, Smith, A, Macnaughton, LS, and French, DN. Strength and Conditioning and Concurrent Training Practices in Elite Rugby Union. J Strength Cond Res 30(12): 3354-3366, 2016-There is limited published research on strength and conditioning (S&C) practices in elite rugby union (RU). Information regarding testing batteries and programme design would provide valuable information to both applied practitioners and researchers investigating the influence of training interventions or preperformance strategies. The aim of this study was to detail the current practices of S&C coaches and sport scientists working in RU. A questionnaire was developed that comprised 7 sections: personal details, physical testing, strength and power development, concurrent training, flexibility development, unique aspects of the programme, and any further relevant information regarding prescribed training programmes. Forty-three (41 men, 2 women; age: 33.1 ± 5.3 years) of 52 (83%) coaches responded to the questionnaire. The majority of practitioners worked with international level and/or professional RU athletes. All respondents believed strength training benefits RU performance and reported that their athletes regularly performed strength training. The clean and back squat were rated the most important prescribed exercises. Forty-one (95%) respondents reported prescribing plyometric exercises and 38 (88%) indicated that periodization strategies were used. Forty-two (98%) practitioners reported conducting physical testing, with body composition being the most commonly tested phenotype. Thirty-three (77%) practitioners indicated that the potential muted strength development associated with concurrent training was considered when programming and 27 (63%) believed that strength before aerobic training was more favorable for strength development than vice versa. This research represents the only published survey to date of S&C practices in northern and southern hemisphere RU.

  10. The Effect of Consolidation Chemotherapy for LA-NSCLC Patients Receiving Concurrent Chemoradiotherapy

    Directory of Open Access Journals (Sweden)

    Yelda Varol

    2016-09-01

    Full Text Available Aim: The efficacy and safety of consolidation chemotherapy (CCT following concurrent chemoradiotherapy are not adequately established for patients with locally advanced non-small-cell lung cancer (LA-NSCLC. In this context, the present study aims to evaluate the efficacy and toxicity of CCT.Material and Method: We retrospectively analyzed the overall survival (OS and progression-free survival (PFS of 83 LA-NSCLC patients treated with concurrent CRT as an initial treatment with (n:20 or without CCT (n:63. All patients were cytohistologically proven to have NSCLC and diagnosed with clinical Stage III (n:48 for IIIA and n:35 for IIIB according to the staging system published by the American Joint Committee on Cancer (AJCC in 2009. All patients received curative thoracic radiotherapy with concurrent platinum doublet chemotherapy. Results: The mean age of the lung cancer patients was 59 (±7.3; 89.2% were male (n:74,and there were only 9 female patients (10.8%.When we compared the outcome of LA-NSCLC patients treated with CCT (median 10.4 months to the patients treated without CCT (median 13.8 months, the log-rank analysis demonstrated a statistically significant difference for an inferior progression-free survival (p=0.046 in patients receiving CCT. However, no significant association was observed for overall survival (17.4, 21 months, respectively (p>0.05. Patients with CCT presented higher levels of hematological side effects compared with the patients without CCT (p

  11. Preoperative Radiation Therapy With Concurrent Capecitabine, Bevacizumab, and Erlotinib for Rectal Cancer: A Phase 1 Trial

    Energy Technology Data Exchange (ETDEWEB)

    Das, Prajnan, E-mail: PrajDas@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Eng, Cathy [Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rodriguez-Bigas, Miguel A.; Chang, George J.; Skibber, John M.; You, Y. Nancy [Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Maru, Dipen M. [Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Munsell, Mark F. [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Clemons, Marilyn V. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kopetz, Scott E.; Garrett, Christopher R.; Shureiqi, Imad [Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Delclos, Marc E.; Krishnan, Sunil; Crane, Christopher H. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-02-01

    Purpose: The goal of this phase 1 trial was to determine the maximum tolerated dose (MTD) of concurrent capecitabine, bevacizumab, and erlotinib with preoperative radiation therapy for rectal cancer. Methods and Materials: Patients with clinical stage II to III rectal adenocarcinoma, within 12 cm from the anal verge, were treated in 4 escalating dose levels, using the continual reassessment method. Patients received preoperative radiation therapy with concurrent bevacizumab (5 mg/kg intravenously every 2 weeks), erlotinib, and capecitabine. Capecitabine dose was increased from 650 mg/m{sup 2} to 825 mg/m{sup 2} orally twice daily on the days of radiation therapy; erlotinib dose was increased from 50 mg orally daily in weeks 1 to 3, to 50 mg daily in weeks 1 to 6, to 100 mg daily in weeks 1 to 6. Patients underwent surgery at least 9 weeks after the last dose of bevacizumab. Results: A total of 19 patients were enrolled, and 18 patients were considered evaluable. No patient had grade 4 acute toxicity, and 1 patient had grade 3 acute toxicity (hypertension). The MTD was not reached. All 18 evaluable patients underwent surgery, with low anterior resection in 7 (39%), proctectomy with coloanal anastomosis in 4 patients (22%), posterior pelvic exenteration in 1 (6%), and abdominoperineal resection in 6 (33%). Of the 18 patients, 8 (44%) had pathologic complete response, and 1 had complete response of the primary tumor with positive nodes. Three patients (17%) had grade 3 postoperative complications (ileus, small bowel obstruction, and infection). With a median follow-up of 34 months, 1 patient developed distant metastasis, and no patient had local recurrence or died. The 3-year disease-free survival was 94%. Conclusions: The combination of preoperative radiation therapy with concurrent capecitabine, bevacizumab, and erlotinib was well tolerated. The pathologic complete response rate appears promising and may warrant further investigation.

  12. Concurrent Associations of Physical Activity and Screen-Based Sedentary Behavior on Obesity Among US Adolescents: A Latent Class Analysis

    OpenAIRE

    Youngdeok Kim

    2016-01-01

    Background: Independent associations of physical activity (PA) and sedentary behavior (SB) with obesity are well documented. However, little is known about the combined associations of these behaviors with obesity in adolescents. The present study examines the prevalence of concurrent levels of PA and SB, and their associations with obesity among US adolescents. Methods: Data from a total of 12 081 adolescents who participated in the Youth Risk Behaviors Survey during 2012–2013 were analyz...

  13. Predictive factors of head and neck squamous cell carcinoma patient tolerance to high-dose cisplatin in concurrent chemoradiotherapy

    OpenAIRE

    Nakano, Kenji; SATO, YASUYOSHI; TOSHIYASU, TAKASHI; SATO, YUKIKO; INAGAKI, LINA; Tomomatsu, Junichi; Sasaki, Toru; SHIMBASHI, WATARU; FUKUSHIMA, HIROFUMI; YONEKAWA, HIROYUKI; Mitani,Hiroki; Kawabata, Kazuyoshi; Takahashi, Shunji

    2015-01-01

    Although high-dose cisplatin is the standard regimen of concurrent chemoradiotherapy (CCRT) for locally advanced head and neck squamous cell carcinoma (HNSCC), varying levels of patient tolerance towards cisplatin have been reported, and the predictive factors of cisplatin tolerance remain to be elucidated. The present study retrospectively reviewed newly diagnosed HNSCC patients who received CCRT. Cisplatin (80 mg/m2) was administered every 3 weeks. The proportion of high-dose cisplatin-tole...

  14. CT colonography: effect of computer-aided detection of colonic polyps as a second and concurrent reader for general radiologists with moderate experience in CT colonography.

    Science.gov (United States)

    Mang, Thomas; Bogoni, Luca; Anand, Vikram X; Chandra, Dass; Curtin, Andrew J; Lev-Toaff, Anna S; Hermosillo, Gerardo; Noah, Ralph; Raykar, Vikas; Salganicoff, Marcos; Shaw, Robert; Summerton, Susan; Tappouni, Rafel F R; Ringel, Helmut; Weber, Michael; Wolf, Matthias; Obuchowski, Nancy A

    2014-07-01

    To assess the effectiveness of computer-aided detection (CAD) as a second reader or concurrent reader in helping radiologists who are moderately experienced in computed tomographic colonography (CTC) to detect colorectal polyps. Seventy CTC datasets (34 patients: 66 polyps ≥6 mm; 36 patients: no abnormalities) were retrospectively reviewed by seven radiologists with moderate CTC experience. After primary unassisted evaluation, a CAD second read and, after a time interval of ≥4 weeks, a CAD concurrent read were performed. Areas under the receiver operating characteristic (ROC) curve (AUC), along with per-segment, per-polyp and per-patient sensitivities, and also reading times, were calculated for each reader with and without CAD. Of seven readers, 86% and 71% achieved a higher accuracy (segment-level AUC) when using CAD as second and concurrent reader respectively. Average segment-level AUCs with second and concurrent CAD (0.853 and 0.864) were significantly greater (p readers' average segment and patient specificity by 0.007 and 0.036 (p = 0.005 and 0.011), respectively. CAD significantly improves the sensitivities of radiologists moderately experienced in CTC for polyp detection, both as second reader and concurrent reader. • CAD helps radiologists with moderate CTC experience to detect polyps ≥6 mm. • Second and concurrent read CAD increase the radiologist's sensitivity for detecting polyps ≥6 mm. • Second read CAD slightly decreases specificity compared with an unassisted read. • Concurrent read CAD is significantly more time-efficient than second read CAD.

  15. Concurrence Measurement for the Two-Qubit Optical and Atomic States

    Directory of Open Access Journals (Sweden)

    Lan Zhou

    2015-06-01

    Full Text Available Concurrence provides us an effective approach to quantify entanglement, which is quite important in quantum information processing applications. In the paper, we mainly review some direct concurrence measurement protocols of the two-qubit optical or atomic system. We first introduce the concept of concurrence for a two-qubit system. Second, we explain the approaches of the concurrence measurement in both a linear and a nonlinear optical system. Third, we introduce some protocols for measuring the concurrence of the atomic entanglement system.

  16. CT colonography: effect of computer-aided detection of colonic polyps as a second and concurrent reader for general radiologists with moderate experience in CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Mang, Thomas; Ringel, Helmut; Weber, Michael [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Bogoni, Luca; Anand, Vikram X.; Hermosillo, Gerardo; Raykar, Vikas; Salganicoff, Marcos; Wolf, Matthias [H IM SY US, Siemens Medical Solutions, Malvern, PA (United States); Chandra, Dass [Temple University, Philadelphia, PA (United States); Curtin, Andrew J. [Tristate Imaging Consultants, Abington, PA (United States); Lev-Toaff, Anna S. [University of Pennsylvania, Philadelphia, PA (United States); Noah, Ralph [Diagnostic Imaging Associates, Wilmington, DE (United States); Shaw, Robert [The Chester County Hospital, West Chester, PA (United States); Summerton, Susan [Albert Einstein Medical Center, Philadelphia, PA (United States); Tappouni, Rafel F.R. [Wake Forest University School of Medicine, Winston-Salem, NC (United States); Obuchowski, Nancy A. [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States)

    2014-07-15

    To assess the effectiveness of computer-aided detection (CAD) as a second reader or concurrent reader in helping radiologists who are moderately experienced in computed tomographic colonography (CTC) to detect colorectal polyps. Seventy CTC datasets (34 patients: 66 polyps ≥6 mm; 36 patients: no abnormalities) were retrospectively reviewed by seven radiologists with moderate CTC experience. After primary unassisted evaluation, a CAD second read and, after a time interval of ≥4 weeks, a CAD concurrent read were performed. Areas under the receiver operating characteristic (ROC) curve (AUC), along with per-segment, per-polyp and per-patient sensitivities, and also reading times, were calculated for each reader with and without CAD. Of seven readers, 86 % and 71 % achieved a higher accuracy (segment-level AUC) when using CAD as second and concurrent reader respectively. Average segment-level AUCs with second and concurrent CAD (0.853 and 0.864) were significantly greater (p < 0.0001) than average AUC in the unaided evaluation (0.781). Per-segment, per-polyp, and per-patient sensitivities for polyps ≥6 mm were significantly higher in both CAD reading paradigms compared with unaided evaluation. Second-read CAD reduced readers' average segment and patient specificity by 0.007 and 0.036 (p = 0.005 and 0.011), respectively. CAD significantly improves the sensitivities of radiologists moderately experienced in CTC for polyp detection, both as second reader and concurrent reader. (orig.)

  17. Syndrome of inappropriate antidiuretic hormone secretion concurrent with liver disease in a dog.

    Science.gov (United States)

    Kang, Min-Hee; Park, Hee-Myung

    2012-05-01

    A 5-year-old female Chihuahua was presented for acute collapse. Laboratory examinations showed markedly elevated levels of hepatobiliary enzymes. Empiric antibiotic therapy for bacterial infection of the liver was ineffective. The clinical signs worsened with the development of hyponatremia with hypoosmolality and elevated urine sodium levels. The dog was suspected of having acute cholangiohepatitis associated with an immune-mediated disease. Subsequently, it was diagnosed with syndrome of inappropriate antidiuretic hormone secretion (SIADH) on the basis of the specific disease criteria. Further tests showed normal function of the adrenal and thyroid glands, and MRI and cerebrospinal fluid (CSF) analysis did not show any intracranial diseases. Immunosuppressive therapy and water restriction resolved the clinical signs and improved the SIADH in this dog. This case indicates that SIADH can occur concurrently with suspected immune-mediated liver disease in dogs.

  18. [Process of change in patients with concurrent substance use - mental health problems].

    Science.gov (United States)

    Acier, Didier; Nadeau, Louise; Landry, Michel

    2007-01-01

    This paper is a retrospective study with a five year follow-up which examines the variations in substance use and the determinants of these variations. This exploratory research studied a sub-sample of 22 participants, selected from an initial sample of 197 patients with concurrent substance use and other mental health disorders. At the quantitative level, the statistical analysis shows an improvement in the problematic use of alcohol and drugs but no change in psychological state, health, family and interpersonals relations, as well as employment. At the qualitative level, the analysis of the participant's subjective view indicates that the two main elements of progression in substance use are the effects and the availability of substances. The main elements of reduction in substance use are the use of services, the personal techniques developed by participants, the family network, physical health, lack of financial resources, "occupational" activities, and a process of maturation.

  19. WE-D-BRE-04: Modeling Optimal Concurrent Chemotherapy Schedules

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, J; Deasy, J O [Memorial Sloan Kettering Cancer Center, New York, NY (United States)

    2014-06-15

    Purpose: Concurrent chemo-radiation therapy (CCRT) has become a more common cancer treatment option with a better tumor control rate for several tumor sites, including head and neck and lung cancer. In this work, possible optimal chemotherapy schedules were investigated by implementing chemotherapy cell-kill into a tumor response model of RT. Methods: The chemotherapy effect has been added into a published model (Jeong et al., PMB (2013) 58:4897), in which the tumor response to RT can be simulated with the effects of hypoxia and proliferation. Based on the two-compartment pharmacokinetic model, the temporal concentration of chemotherapy agent was estimated. Log cell-kill was assumed and the cell-kill constant was estimated from the observed increase in local control due to concurrent chemotherapy. For a simplified two cycle CCRT regime, several different starting times and intervals were simulated with conventional RT regime (2Gy/fx, 5fx/wk). The effectiveness of CCRT was evaluated in terms of reduction in radiation dose required for 50% of control to find the optimal chemotherapy schedule. Results: Assuming the typical slope of dose response curve (γ50=2), the observed 10% increase in local control rate was evaluated to be equivalent to an extra RT dose of about 4 Gy, from which the cell-kill rate of chemotherapy was derived to be about 0.35. Best response was obtained when chemotherapy was started at about 3 weeks after RT began. As the interval between two cycles decreases, the efficacy of chemotherapy increases with broader range of optimal starting times. Conclusion: The effect of chemotherapy has been implemented into the resource-conservation tumor response model to investigate CCRT. The results suggest that the concurrent chemotherapy might be more effective when delayed for about 3 weeks, due to lower tumor burden and a larger fraction of proliferating cells after reoxygenation.

  20. Knowledge Management tools integration within DLR's concurrent engineering facility

    Science.gov (United States)

    Lopez, R. P.; Soragavi, G.; Deshmukh, M.; Ludtke, D.

    The complexity of space endeavors has increased the need for Knowledge Management (KM) tools. The concept of KM involves not only the electronic storage of knowledge, but also the process of making this knowledge available, reusable and traceable. Establishing a KM concept within the Concurrent Engineering Facility (CEF) has been a research topic of the German Aerospace Centre (DLR). This paper presents the current KM tools of the CEF: the Software Platform for Organizing and Capturing Knowledge (S.P.O.C.K.), the data model Virtual Satellite (VirSat), and the Simulation Model Library (SimMoLib), and how their usage improved the Concurrent Engineering (CE) process. This paper also exposes the lessons learned from the introduction of KM practices into the CEF and elaborates a roadmap for the further development of KM in CE activities at DLR. The results of the application of the Knowledge Management tools have shown the potential of merging the three software platforms with their functionalities, as the next step towards the fully integration of KM practices into the CE process. VirSat will stay as the main software platform used within a CE study, and S.P.O.C.K. and SimMoLib will be integrated into VirSat. These tools will support the data model as a reference and documentation source, and as an access to simulation and calculation models. The use of KM tools in the CEF aims to become a basic practice during the CE process. The settlement of this practice will result in a much more extended knowledge and experience exchange within the Concurrent Engineering environment and, consequently, the outcome of the studies will comprise higher quality in the design of space systems.