511 research outputs found

    Improved Algorithms for Approximate String Matching (Extended Abstract)

    Get PDF
    The problem of approximate string matching is important in many different areas such as computational biology, text processing and pattern recognition. A great effort has been made to design efficient algorithms addressing several variants of the problem, including comparison of two strings, approximate pattern identification in a string or calculation of the longest common subsequence that two strings share. We designed an output sensitive algorithm solving the edit distance problem between two strings of lengths n and m respectively in time O((s-|n-m|)min(m,n,s)+m+n) and linear space, where s is the edit distance between the two strings. This worst-case time bound sets the quadratic factor of the algorithm independent of the longest string length and improves existing theoretical bounds for this problem. The implementation of our algorithm excels also in practice, especially in cases where the two strings compared differ significantly in length. Source code of our algorithm is available at http://www.cs.miami.edu/\~dimitris/edit_distanceComment: 10 page

    Evaluation of microflow configurations for scale inhibition and serial X-ray diffraction analysis of crystallization processes

    No full text
    The clean and reproducible conditions provided by microfluidic devices are ideal sample environments for in situ analyses of chemical and biochemical reactions and assembly processes. However, the small size of microchannels makes investigating the crystallization of poorly soluble materials on-chip challenging due to crystal nucleation and growth that result in channel fouling and blockage. Here, we demonstrate a reusable insert-based microfluidic platform for serial X-ray diffraction analysis and examine scale formation in response to continuous and segmented flow configurations across a range of temperatures. Under continuous flow, scale formation on the reactor walls begins almost immediately on mixing of the crystallizing species, which over time results in occlusion of the channel. Depletion of ions at the start of the channel results in reduced crystallization towards the end of the channel. Conversely, segmented flow can control crystallization, so it occurs entirely within the droplet. Consequently, the spatial location within the channel represents a temporal point in the crystallization process. Whilst each method can provide useful crystallographic information, time-resolved information is lost when reactor fouling occurs and changes the solution conditions with time. The flow within a single device can be manipulated to give a broad range of information addressing surface interaction or solution crystallization

    Collusion through Joint R&D: An Empirical Assessment

    Get PDF
    This paper tests whether upstream R&D cooperation leads to downstream collusion. We consider an oligopolistic setting where firms enter in research joint ventures (RJVs) to lower production costs or coordinate on collusion in the product market. We show that a sufficient condition for identifying collusive behavior is a decline in the market share of RJV-participating firms, which is also necessary and sufficient for a decrease in consumer welfare. Using information from the US National Cooperation Research Act, we estimate a market share equation correcting for the endogeneity of RJV participation and R&D expenditures. We find robust evidence that large networks between direct competitors – created through firms being members in several RJVs at the same time – are conducive to collusive outcomes in the product market which reduce consumer welfare. By contrast, RJVs among non-competitors are efficiency enhancing

    Wake up, wake up! It's me! It's my life! patient narratives on person-centeredness in the integrated care context: a qualitative study

    Get PDF
    Person-centered care emphasizes a holistic, humanistic approach that puts patients first, at the center of medical care. Person-centeredness is also considered a core element of integrated care. Yet typologies of integrated care mainly describe how patients fit within integrated services, rather than how services fit into the patient's world. Patient-centeredness has been commonly defined through physician's behaviors aimed at delivering patient-centered care. Yet, it is unclear how 'person-centeredness' is realized in integrated care through the patient voice. We aimed to explore patient narratives of person-centeredness in the integrated care context

    Environmental Factors in the Relapse and Recurrence of Inflammatory Bowel Disease:A Review of the Literature

    Get PDF
    The causes of relapse in patients with Crohn's disease (CD) and ulcerative colitis (UC) are largely unknown. This paper reviews the epidemiological and clinical data on how medications (non-steroidal anti-inflammatory drugs, estrogens and antibiotics), lifestyle factors (smoking, psychological stress, diet and air pollution) may precipitate clinical relapses and recurrence. Potential biological mechanisms include: increasing thrombotic tendency, imbalances in prostaglandin synthesis, alterations in the composition of gut microbiota, and mucosal damage causing increased permeability

    Effects of a Government-Academic Partnership: Has the NSF-Census Bureau Research Network Helped Improve the U.S. Statistical System?

    Get PDF
    The National Science Foundation-Census Bureau Research Network (NCRN) was established in 2011 to create interdisciplinary research nodes on methodological questions of interest and significance to the broader research community and to the Federal Statistical System (FSS), particularly to the Census Bureau. The activities to date have covered both fundamental and applied statistical research and have focused at least in part on the training of current and future generations of researchers in skills of relevance to surveys and alternative measurement of economic units, households, and persons. This article focuses on some of the key research findings of the eight nodes, organized into six topics: (1) improving census and survey data-quality and data collection methods; (2) using alternative sources of data; (3) protecting privacy and confidentiality by improving disclosure avoidance; (4) using spatial and spatio-temporal statistical modeling to improve estimates; (5) assessing data cost and data-quality tradeoffs; and (6) combining information from multiple sources. The article concludes with an evaluation of the ability of the FSS to apply the NCRN’s research outcomes, suggests some next steps, and discusses the implications of this research-network model for future federal government research initiatives

    Virtual money, practices and moral orders in Second Life

    Get PDF
    Virtual monies present a limit case in debates about money's moral and political entanglements between sociologists, anthropologists, and economists. Digitized virtual monies seem ephemeral, almost ideal typical examples of money as a pure medium of exchange. This paper begins with the premise that virtual monies are as value-laden and morally entangled as any other form of money. This assertion is demonstrated by exploring how one type of virtual money, the Linden dollar (L$), and some of its associated practices are bound up with research participants' moral categories and judgments in the virtual world of Second Life (SL). Participants' accounts of virtual money practices are linked to moral attributes, sometimes in stark ‘good’ or ‘bad’ dichotomies, but also in more nuanced terms. These framings reproduce classifications of people and practices along a continuum with virtuousness at one end and maliciousness or harm at the other, passing through various states of possible moral dubiousness. For respondents, these two judgments go together; people are what they do with money. As a result, respondents decide what ‘people like that’ deserve. Evaluating someone's money practices means assessing the person. Participants' accounts of Linden dollar practices overlap with explanations of what SL is and how residents should live there. In SL, money is a form of material culture through which appropriate ways of being in the world are debated and reproduced

    Temperature and spatial connectivity drive patterns in freshwater macroinvertebrate diversity across the Arctic

    Get PDF
    Warming in the Arctic is predicted to change freshwater biodiversity through loss of unique taxa and northward range expansion of lower latitude taxa. Detecting such changes requires establishing circumpolar baselines for diversity, and understanding the primary drivers of diversity. We examined benthic macroinvertebrate diversity using a circumpolar dataset of &gt;1,500 Arctic lake and river sites. Rarefied α diversity within catchments was assessed along latitude and temperature gradients. Community composition was assessed through region-scale analysis of ÎČ diversity and its components (nestedness and turnover), and analysis of biotic–abiotic relationships. Rarefied α diversity of lakes and rivers declined with increasing latitude, although more strongly across mainland regions than islands. Diversity was strongly related to air temperature, with the lowest diversity in the coldest catchments. Regional dissimilarity was highest when mainland regions were compared with islands, suggesting that connectivity limitations led to the strongest dissimilarity. High contributions of nestedness indicated that island regions contained a subset of the taxa found in mainland regions. High Arctic rivers and lakes were predominately occupied by Chironomidae and Oligochaeta, whereas Ephemeroptera, Plecoptera, and Trichoptera taxa were more abundant at lower latitudes. Community composition was strongly associated with temperature, although geology and precipitation were also important correlates. The strong association with temperature supports the prediction that warming will increase Arctic macroinvertebrate diversity, although low diversity on islands suggests that this increase will be limited by biogeographical constraints. Long-term harmonised monitoring across the circumpolar region is necessary to detect such changes to diversity and inform science-based management.</p

    Determinants of self-reporting under the European corporate leniency program

    Full text link
    We empirically investigate the determinants of self-reporting under the European corporate leniency program. Applying a data set consisting of 442 firm groups that participated in 76 cartels decided by the European Commission between 2000 and 2011, we find that the probability of a firm becoming the chief witness increases with its character as repeat offender, the size of the expected basic fine, the number of countries active in one group as well as the size of the firm’s share in the cartelized market. Our results have important implications for an effective prosecution of anti-cartel law infringers

    Priority setting in primary health care - dilemmas and opportunities: a focus group study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Swedish health care authorities use three key criteria to produce national guidelines for local priority setting: severity of the health condition, expected patient benefit, and cost-effectiveness of medical intervention. Priority setting in primary health care (PHC) has significant implications for health costs and outcomes in the health care system. Nevertheless, these guidelines have been implemented to a very limited degree in PHC. The objective of the study was to qualitatively assess how general practitioners (GPs) and nurses perceive the application of the three key priority-setting criteria.</p> <p>Methods</p> <p>Focus groups were held with GPs and nurses at primary health care centres, where the staff had a short period of experience in using the criteria for prioritising in their daily work.</p> <p>Results</p> <p>The staff found the three key priority-setting criteria (severity, patient benefit, and cost-effectiveness) to be valuable for priority setting in PHC. However, when the criteria were applied in PHC, three additional dimensions were identified: 1) viewpoint (medical or patient's), 2) timeframe (now or later), and 3) evidence level (group or individual).</p> <p>Conclusions</p> <p>The three key priority-setting criteria were useful. Considering the three additional dimensions might enhance implementation of national guidelines in PHC and is probably a prerequisite for the criteria to be useful in priority setting for individual patients.</p
    • 

    corecore