314 research outputs found

    Removal operations in nD generalized maps for efficient homology computation

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    In this paper, we present an efficient way for computing homology generators of nD generalized maps. The algorithm proceeds in two steps: (1) cell removals reduces the number of cells while preserving homology; (2) homology generator computation is performed on the reduced object by reducing incidence matrices into their Smith-Agoston normal form. In this paper, we provide a definition of cells that can be removed while preserving homology. Some results on 2D and 3D homology generators computation are presented

    On the Integration of Automatic Deployment into the ABS Modeling Language

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    In modern software systems, deployment is an integral and critical part of application development (see, e.g., the DevOps approach to software development). Nevertheless, deployment is usually overlooked at the modeling level, thus losing the possibility to perform deployment conscious decisions during the early stages of development. In this paper, we address the problem of promoting deployment as an integral part of modeling, by focusing on the Abstract Behavioral Specification (ABS) language used for the specification of models of systems composed of concurrent objects consuming resources provided by deployment components. We extend ABS with class annotations expressing the resource requirements of the objects of that class. Then we define a tool that, starting from a high-level declaration of the desired system, computes a model instance of such system that optimally distributes objects over available deployment components

    Reversing Single Sessions

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    Session-based communication has gained a widespread acceptance in practice as a means for developing safe communicating systems via structured interactions. In this paper, we investigate how these structured interactions are affected by reversibility, which provides a computational model allowing executed interactions to be undone. In particular, we provide a systematic study of the integration of different notions of reversibility in both binary and multiparty single sessions. The considered forms of reversibility are: one for completely reversing a given session with one backward step, and another for also restoring any intermediate state of the session with either one backward step or multiple ones. We analyse the costs of reversing a session in all these different settings. Our results show that extending binary single sessions to multiparty ones does not affect the reversibility machinery and its costs

    Remove Noise in Video with 3D Topological Maps

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    International audienceIn this paper we present a new method for foreground masks denoising in videos. Our main idea is to consider videos as 3D images and to deal with regions in these images. Denoising is thus simply achieved by merging foreground regions corresponding to noise with background regions. In this framework, the main question is the definition of a cri-terion allowing to decide if a region corresponds to noise or not. Thanks to our complete cellular description of 3D images, we can propose an advanced criterion based on Betti numbers, a topological invariant. Our results show the interest of our approach which gives better results than previous methods

    Adherence to self-administered tuberculosis treatment in a high HIV-prevalence setting: a cross-sectional survey in Homa Bay, Kenya.

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    Good adherence to treatment is crucial to control tuberculosis (TB). Efficiency and feasibility of directly observed therapy (DOT) under routine program conditions have been questioned. As an alternative, Médecins sans Frontières introduced self-administered therapy (SAT) in several TB programs. We aimed to measure adherence to TB treatment among patients receiving TB chemotherapy with fixed dose combination (FDC) under SAT at the Homa Bay district hospital (Kenya). A second objective was to compare the adherence agreement between different assessment tools

    Programmatic Management of Drug-Resistant Tuberculosis: An Updated Research Agenda.

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    There are numerous challenges in delivering appropriate treatment for multidrug-resistant tuberculosis (MDR-TB) and the evidence base to guide those practices remains limited. We present the third updated Research Agenda for the programmatic management of drug-resistant TB (PMDT), assembled through a literature review and survey

    Delayed treatment of tuberculosis patients in rural areas of Yogyakarta province, Indonesia

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    <p>Abstract</p> <p>Background</p> <p>In year 2000, the entire population in Indonesia was 201 million and 57.6 percent of that was living in rural areas. This paper reports analyses that address to what extent the rural structure influence the way TB patients seek care prior to diagnosis by a DOTS facility.</p> <p>Methods</p> <p>We documented healthcare utilization pattern of smear positive TB patients prior to diagnosis and treatment by DOTS services (health centre, chest clinic, public and private hospital) in Yogyakarta province. We calculated the delay in treatment as the number of weeks between the onset of symptoms and the start of DOTS treatment. Statistical analysis was carried out with Epi Info version 3.3 (October 5, 2004).</p> <p>Results</p> <p>The only factor which was significantly associated with total delay was urban-rural setting (p = < 0.0001). The median total delay for TB patients in urban districts was 8 (1<sup>st </sup>Quartile = 4; 3<sup>rd </sup>Quartile = 12) weeks compared to 12 (1<sup>st </sup>Quartile = 7; 3<sup>rd </sup>Quartile = 23) weeks for patients in rural districts. Multivariate analysis suggested no confounding between individual factors and urban-rural setting remained as the main factor for total delay (p = < 0.0001). Primary health centre was the first choice provider for most (38.7%) of these TB patients. Urban-rural setting was also the only factor which was significantly associated with choice of first provider (p = 0.03).</p> <p>Conclusion</p> <p>Improving access to DOTS services in rural areas is an area of vital importance in aiming to make progress toward achieving TB control targets in Indonesia.</p

    Long Delays and Missed Opportunities in Diagnosing Smear-Positive Pulmonary Tuberculosis in Kampala, Uganda: A Cross-Sectional Study

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    BACKGROUND: Early detection and treatment of tuberculosis cases are the hallmark of successful tuberculosis control. We conducted a cross-sectional study at public primary health facilities in Kampala city, Uganda to quantify diagnostic delay among pulmonary tuberculosis (PTB) patients, assess associated factors, and describe trajectories of patients' health care seeking. METHODOLOGY/PRINCIPAL FINDINGS: Semi-structured interviews with new smear-positive PTB patients (≥ 15 years) registered for treatment. Between April 2007 and April 2008, 253 patients were studied. The median total delay was 8 weeks (IQR 4-12), median patient delay was 4 weeks (inter-quartile range [IQR] 1-8) and median health service delay was 4 weeks (IQR 2-8). Long total delay (>14 weeks) was observed for 61/253 (24.1%) of patients, long health service delay (>6 weeks) for 71/242 (29.3%) and long patient delay (>8 weeks) for 47/242 (19.4%). Patients who knew that TB was curable were less likely to have long total delay (adjusted Odds Ratio [aOR] 0.28; 95%CI 0.11-0.73) and long patient delay (aOR 0.36; 95%CI 0.13-0.97). Being female (aOR 1.98; 95%CI 1.06-3.71), staying for more than 5 years at current residence (aOR 2.24 95%CI 1.18-4.27) and having been tested for HIV before (aOR 3.72; 95%CI 1.42-9.75) was associated with long health service delay. Health service delay contributed 50% of the total delay. Ninety-one percent (231) of patients had visited one or more health care providers before they were diagnosed, for an average (median) of 4 visits (range 1-30). All but four patients had systemic symptoms by the time the diagnosis of TB was made. CONCLUSIONS/SIGNIFICANCE: Diagnostic delay among tuberculosis patients in Kampala is common and long. This reflects patients waiting too long before seeking care and health services waiting until systemic symptoms are present before examining sputum smears; this results in missed opportunities for diagnosis
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