1,936 research outputs found

    Chemoprevention of lung cancer—from biology to clinical reality

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    Lung cancer is the commonest cause of cancer death in developed countries and throughout the world. Cigarette smoking is the main risk factor for lung cancer and ex-smokers today comprise ∟50% of all new lung cancer cases. Chemoprevention builds on the concepts of field of cancerization and multistep carcinogenesis and can be defined as the use of natural or chemical compounds to prevent, inhibit or reverse the process of carcinogenesis. So far, chemoprevention studies in lung cancer have failed to reduce lung cancer mortality. New developments in biotechnology have made it possible to define more accurately high-risk populations, make earlier diagnosis possible, and allow more specific targeted therapies to be developed. Both the development and validation of biomarkers, for the selection of high-risk study populations and for response evaluation in chemoprevention studies, are important for the faster turnover of studies evaluating new agents. This article reviews the current status and describes the perspectives for new approaches in the chemoprevention of lung cance

    A Computational Approach for Designing Tiger Corridors in India

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    Wildlife corridors are components of landscapes, which facilitate the movement of organisms and processes between intact habitat areas, and thus provide connectivity between the habitats within the landscapes. Corridors are thus regions within a given landscape that connect fragmented habitat patches within the landscape. The major concern of designing corridors as a conservation strategy is primarily to counter, and to the extent possible, mitigate the effects of habitat fragmentation and loss on the biodiversity of the landscape, as well as support continuance of land use for essential local and global economic activities in the region of reference. In this paper, we use game theory, graph theory, membership functions and chain code algorithm to model and design a set of wildlife corridors with tiger (Panthera tigris tigris) as the focal species. We identify the parameters which would affect the tiger population in a landscape complex and using the presence of these identified parameters construct a graph using the habitat patches supporting tiger presence in the landscape complex as vertices and the possible paths between them as edges. The passage of tigers through the possible paths have been modelled as an Assurance game, with tigers as an individual player. The game is played recursively as the tiger passes through each grid considered for the model. The iteration causes the tiger to choose the most suitable path signifying the emergence of adaptability. As a formal explanation of the game, we model this interaction of tiger with the parameters as deterministic finite automata, whose transition function is obtained by the game payoff.Comment: 12 pages, 5 figures, 6 tables, NGCT conference 201

    Cytogerontology since 1881: A reappraisal of August Weismann and a review of modern progress

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    Cytogerontology, the science of cellular ageing, originated in 1881 with the prediction by August Weismann that the somatic cells of higher animals have limited division potential. Weismann's prediction was derived by considering the role of natural selection in regulating the duration of an organism's life. For various reasons, Weismann's ideas on ageing fell into neglect following his death in 1914, and cytogerontology has only reappeared as a major research area following the demonstration by Hayflick and Moorhead in the early 1960s that diploid human fibroblasts are restricted to a finite number of divisions in vitro. In this review we give a detailed account of Weismann's theory, and we reveal that his ideas were both more extensive in their scope and more pertinent to current research than is generally recognised. We also appraise the progress which has been made over the past hundred years in investigating the causes of ageing, with particular emphasis being given to (i) the evolution of ageing, and (ii) ageing at the cellular level. We critically assess the current state of knowledge in these areas and recommend a series of points as primary targets for future research

    Phase III randomised trial of doxorubicin-based chemotherapy compared with platinum-based chemotherapy in small-cell lung cancer

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    This randomised trial compared platinum-based to anthracycline-based chemotherapy in patients with small-cell lung cancer (limited or extensive stage) and ⩽2 adverse prognostic factors. Patients were randomised to receive six cycles of either ACE (doxorubicin 50 mg/m2 i.v., cyclophosphamide 1 g/m2 i.v. and etoposide 120 mg/m2 i.v. on day 1, then etoposide 240 mg/m2 orally for 2 days) or PE (cisplatin 80 mg/m2 and etoposide 120 mg/m2 i.v. on day 1, then etoposide 240 mg/m2 orally for 2 days) given for every 3 weeks. For patients where cisplatin was not suitable, carboplatin (AUC6) was substituted. A total of 280 patients were included (139 ACE, 141 PE). The response rates were 72% for ACE and 77% for PE. One-year survival rates were 34 and 38% (P=0.497), respectively and 2-year survival was the same (12%) for both arms. For LD patients, the median survival was 10.9 months for ACE and 12.6 months for PE (P=0.51); for ED patients median survival was 8.3 months and 7.5 months, respectively. More grades 3 and 4 neutropenia (90 vs 57%, P<0.005) and grades 3 and 4 infections (73 vs 29%, P<0.005) occurred with ACE, resulting in more days of hospitalisation and greater i.v. antibiotic use. ACE was associated with a higher risk of neutropenic sepsis than PE and with a trend towards worse outcome in patients with LD, and should not be studied further in this group of patients

    Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

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    The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

    Compressed representation of a partially defined integer function over multiple arguments

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    In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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