14,382 research outputs found

    Grand Challenges of Traceability: The Next Ten Years

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    In 2007, the software and systems traceability community met at the first Natural Bridge symposium on the Grand Challenges of Traceability to establish and address research goals for achieving effective, trustworthy, and ubiquitous traceability. Ten years later, in 2017, the community came together to evaluate a decade of progress towards achieving these goals. These proceedings document some of that progress. They include a series of short position papers, representing current work in the community organized across four process axes of traceability practice. The sessions covered topics from Trace Strategizing, Trace Link Creation and Evolution, Trace Link Usage, real-world applications of Traceability, and Traceability Datasets and benchmarks. Two breakout groups focused on the importance of creating and sharing traceability datasets within the research community, and discussed challenges related to the adoption of tracing techniques in industrial practice. Members of the research community are engaged in many active, ongoing, and impactful research projects. Our hope is that ten years from now we will be able to look back at a productive decade of research and claim that we have achieved the overarching Grand Challenge of Traceability, which seeks for traceability to be always present, built into the engineering process, and for it to have "effectively disappeared without a trace". We hope that others will see the potential that traceability has for empowering software and systems engineers to develop higher-quality products at increasing levels of complexity and scale, and that they will join the active community of Software and Systems traceability researchers as we move forward into the next decade of research

    Pregnancy with chronic myeloid leukemia: case report and literature review

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    Chronic myeloid leukemia (CML) is a rare condition during reproductive age. Still, women may present with pre-existing or newly diagnosed CML during pregnancy. The management of chronic myeloid leukemia during pregnancy requires balancing the well-being of the mother with that of fetus. Tyrosine Kinase inhibitors are considered the most effective drug against CML but they are still not considered safe during pregnancy and breast feeding. So, there is a need for management of CML with alternate drugs during pregnancy. Here we report a case of a 26-year-old lady who was diagnosed with chronic myelogenous leukemia (CML) at 20 weeks of gestation and had an atypical chromosome translocation t (9:22). She was managed jointly by obstetrician and haemato-oncologist for the remainder of her pregnancy and eventually she delivered a healthy baby at term

    Cluster formation and anomalous fundamental diagram in an ant trail model

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    A recently proposed stochastic cellular automaton model ({\it J. Phys. A 35, L573 (2002)}), motivated by the motions of ants in a trail, is investigated in detail in this paper. The flux of ants in this model is sensitive to the probability of evaporation of pheromone, and the average speed of the ants varies non-monotonically with their density. This remarkable property is analyzed here using phenomenological and microscopic approximations thereby elucidating the nature of the spatio-temporal organization of the ants. We find that the observations can be understood by the formation of loose clusters, i.e. space regions of enhanced, but not maximal, density.Comment: 11 pages, REVTEX, with 11 embedded EPS file

    Optimizing Traffic Lights in a Cellular Automaton Model for City Traffic

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    We study the impact of global traffic light control strategies in a recently proposed cellular automaton model for vehicular traffic in city networks. The model combines basic ideas of the Biham-Middleton-Levine model for city traffic and the Nagel-Schreckenberg model for highway traffic. The city network has a simple square lattice geometry. All streets and intersections are treated equally, i.e., there are no dominant streets. Starting from a simple synchronized strategy we show that the capacity of the network strongly depends on the cycle times of the traffic lights. Moreover we point out that the optimal time periods are determined by the geometric characteristics of the network, i.e., the distance between the intersections. In the case of synchronized traffic lights the derivation of the optimal cycle times in the network can be reduced to a simpler problem, the flow optimization of a single street with one traffic light operating as a bottleneck. In order to obtain an enhanced throughput in the model improved global strategies are tested, e.g., green wave and random switching strategies, which lead to surprising results.Comment: 13 pages, 10 figure

    Distribution of dwell times of a ribosome: effects of infidelity, kinetic proofreading and ribosome crowding

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    Ribosome is a molecular machine that polymerizes a protein where the sequence of the amino acid residues, the monomers of the protein, is dictated by the sequence of codons (triplets of nucleotides) on a messenger RNA (mRNA) that serves as the template. The ribosome is a molecular motor that utilizes the template mRNA strand also as the track. Thus, in each step the ribosome moves forward by one codon and, simultaneously, elongates the protein by one amino acid. We present a theoretical model that captures most of the main steps in the mechano-chemical cycle of a ribosome. The stochastic movement of the ribosome consists of an alternating sequence of pause and translocation; the sum of the durations of a pause and the following translocation is the time of dwell of the ribosome at the corresponding codon. We derive the analytical expression for the distribution of the dwell times of a ribosome in our model. Whereever experimental data are available, our theoretical predictions are consistent with those results. We suggest appropriate experiments to test the new predictions of our model, particularly, the effects of the quality control mechanism of the ribosome and that of their crowding on the mRNA track.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Physical Biology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at DOI:10.1088/1478-3975/8/2/02600

    Glitch subtraction from gravitational wave data using adaptive spline fitting

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    Transient signals of instrumental and environmental origins ( glitches ) in gravitational wave data elevate the false alarm rate of searches for astrophysical signals and reduce their sensitivity. Glitches that directly overlap astrophysical signals hinder their detection and worsen parameter estimation errors. As the fraction of data occupied by detectable astrophysical signals will be higher in next generation detectors, such problematic overlaps could become more frequent. These adverse effects of glitches can be mitigated by estimating and subtracting them out from the data, but their unpredictable waveforms and large morphological diversity pose a challenge. Subtraction of glitches using data from auxiliary sensors as predictors works but not for the majority of cases. Thus, there is a need for nonparametric glitch mitigation methods that do not require auxiliary data, work for a large variety of glitches, and have minimal effect on astrophysical signals in the case of overlaps. In order to cope with the high rate of glitches, it is also desirable that such methods be computationally fast. We show that adaptive spline fitting, in which the placement of free knots is optimized to estimate both smooth and non-smooth curves in noisy data, offers a promising approach to satisfying these requirements for broadband short-duration glitches, the type that appear quite frequently. The method is demonstrated on glitches drawn from three distinct classes in the Gravity Spy database as well as on the glitch that overlapped the double neutron star signal GW170817. The impact of glitch subtraction on the GW170817 signal, or those like it injected into the data, is seen to be negligible

    Laparoscopic evaluation of pelvic organ in case of subfertility

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    Background: Globally subfertility affects 10-15% of couple. All these people need proper evaluation and treatment. Now a days laparoscopy considered as a gold standard procedure for evaluation of pelvic organ. The aim of this study was to find out the different causes of female factor infertility with the help of laparoscopy.Methods: This retrospective study was conducted in infertility clinic of BIRDEM hospital, Dhaka, Bangladesh during the period of May, 2007 to October 2007. The study group comprised 100 cases of infertile patients.Results: In this study, among 100 patients 68% had primary and 32% had secondary infertility. In laparoscopy majority (55.0%) had normal ovary, 20.0% had cystic change with thick capsule in right ovary and 22% had in left ovary, 7.0% had endometriosis, 8.0% had adhesion, 10.0% had simple cyst in right ovary and 8% had in left ovary and rest could not be visualized. 79.4% right and 77.9% left fallopian tube patent in primary subfertility cases and 56.3% right and 59.4% left tube normal in secondary subfertility cases. Both fallopian tube patent in 62%, unilateral block 21% and bilateral block in 17% cases in this study peritoneum was normal in 78% cases, 8% cases there was endometriosis and 14% cases there was adhesion of fallopian tube with the ovary, adhesion of uterus with intestine and also with bladder.Conclusions: Laparoscopy is an important tool for diagnosing anatomical and pathological abnormalities of pelvic organ which has a major role in subfertility management.

    Probing the superconducting ground state of the noncentrosymmetric superconductors CaTSi3 (T = Ir, Pt) using muon-spin relaxation and rotation

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    The superconducting properties of CaTSi3 (where T = Pt and Ir) have been investigated using muon spectroscopy. Our muon-spin relaxation results suggest that in both these superconductors time-reversal symmetry is preserved, while muon-spin rotation data show that the temperature dependence of the superfluid density is consistent with an isotropic s-wave gap. The magnetic penetration depths and upper critical fields determined from our transverse-field muon-spin rotation spectra are found to be 448(6) and 170(6) nm, and 3800(500) and 1700(300) G, for CaPtSi3 and CaIrSi3 respectively. The superconducting coherence lengths of the two materials have also been determined and are 29(2) nm for CaPtSi3 and 44(4) nm for CaIrSi3.Comment: 6 pages, 7 figure
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