1,444 research outputs found

    Statistical Mechanics of Semi-Supervised Clustering in Sparse Graphs

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    We theoretically study semi-supervised clustering in sparse graphs in the presence of pairwise constraints on the cluster assignments of nodes. We focus on bi-cluster graphs, and study the impact of semi-supervision for varying constraint density and overlap between the clusters. Recent results for unsupervised clustering in sparse graphs indicate that there is a critical ratio of within-cluster and between-cluster connectivities below which clusters cannot be recovered with better than random accuracy. The goal of this paper is to examine the impact of pairwise constraints on the clustering accuracy. Our results suggests that the addition of constraints does not provide automatic improvement over the unsupervised case. When the density of the constraints is sufficiently small, their only impact is to shift the detection threshold while preserving the criticality. Conversely, if the density of (hard) constraints is above the percolation threshold, the criticality is suppressed and the detection threshold disappears.Comment: 8 pages, 4 figure

    Eventscapes and the creation of event legacies

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    Attention is directed to the difference in event legacies created by mega-events which often cause dramatic physical changes in urban environments and those which accompany events which leave very little imprint on the landscape where they are held. The Tour Down Under cycle race, which is held annually in South Australia, is examined as an example of the latter. The spatial pattern of the event and the range of settings which support it are presented as an eventscape by drawing on concepts such as Bale's [1994. Landscapes of Modern Sport. Leicester: Leicester University Press] sportscape and Bitner's [1992. “Servicescapes: The Impact of Physical Surroundings on Customers and Employees.” The Journal of Marketing 56 (2): 57–71] servicescape. These interpretations are used to identify legacies. It is suggested that the creation of positive legacies requires communities that are part of the eventscape to engage in imaginative leveraging that is consistent with long-term strategic objectives. The paper offers a new definition of eventscape

    New CRISPR Mutagenesis Strategies Reveal Variation in Repair Mechanisms among Fungi

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    We have created new vectors for clustered regularly interspaced short palindromic repeat (CRISPR) mutagenesis in Candida albicans, Saccharomyces cerevisiae, Candida glabrata, and Naumovozyma castellii These new vectors permit a comparison of the requirements for CRISPR mutagenesis in each of these species and reveal different dependencies for repair of the Cas9 double-stranded break. Both C. albicans and S. cerevisiae rely heavily on homology-directed repair, whereas C. glabrata and N. castellii use both homology-directed and nonhomologous end-joining pathways. The high efficiency of these vectors permits the creation of unmarked deletions in each of these species and the recycling of the dominant selection marker for serial mutagenesis in prototrophs. A further refinement, represented by the "Unified" Solo vectors, incorporates Cas9, guide RNA, and repair template into a single vector, thus enabling the creation of vector libraries for pooled screens. To facilitate the design of such libraries, we have identified guide sequences for each of these species with updated guide selection algorithms.IMPORTANCE CRISPR-mediated genome engineering technologies have revolutionized genetic studies in a wide range of organisms. Here we describe new vectors and guide sequences for CRISPR mutagenesis in the important human fungal pathogens C. albicans and C. glabrata, as well as in the related yeasts S. cerevisiae and N. castellii The design of these vectors enables efficient serial mutagenesis in each of these species by leaving few, if any, exogenous sequences in the genome. In addition, we describe strategies for the creation of unmarked deletions in each of these species and vector designs that permit the creation of vector libraries for pooled screens. These tools and strategies promise to advance genetic engineering of these medically and industrially important species.National Institutes of Health (U.S.) (Grant GM035010)National Institutes of Health (U.S.) (Grant GM118135)National Institutes of Health (U.S.) (Grant R15AI130950

    Planning and Leveraging Event Portfolios: Towards a Holistic Theory

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    This conceptual paper seeks to advance the discourse on the leveraging and legacies of events by examining the planning, management, and leveraging of event portfolios. This examination shifts the common focus from analyzing single events towards multiple events and purposes that can enable cross-leveraging among different events in pursuit of attainment and magnification of specific ends. The following frameworks are proposed: (1) event portfolio planning and leveraging, and (2) analyzing events networks and inter-organizational linkages. These frameworks are intended to provide, at this infancy stage of event portfolios research, a solid ground for building theory on the management of different types and scales of events within the context of a portfolio aimed to obtain, optimize and sustain tourism, as well as broader community benefits

    Cancer worry among Norwegian male BRCA1/2 mutation carriers

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    This qualitative study explored the experiences of Norwegian men after being identified as BRCA 1/2 mutation-positive. Only limited knowledge is available on this topic; therefore, the aim of this study was to gain a deeper insight from the men’s own perspectives. Data were collected from in-depth interviews with 15 men and seven of their partners. The participants described fear of cancer development, and two main narrative patterns were identified: fear for their own health, including fear of developing cancer, and negative feelings about responsibility for others’ health. The men expressed fear of developing cancer themselves and described a need for genetic risk information. They were also deeply concerned about how the mutation might affect their children and other relatives. There is a need for guidelines concerning genetic risk information and follow-up programs for male BRCA 1/2 mutation carriers. This study adds valuable contextual insights into their experiences of living with fear of cancer

    Assessment of Personal Care Product Use and Perceptions of Use in a Sample of US Adults Affiliated with a University in the Northeast

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    Evidence supports unequal burdens of chemical exposures from personal care products (PCPs) among some groups, namely femme-identifying and racial and ethnic minorities. In this study, we implemented an online questionnaire to assess PCP purchasing and usage behaviors and perceptions of use among a sample of US adults recruited at a Northeastern university. We collected PCP use across seven product categories (hair, beauty, skincare, perfumes/colognes, feminine hygiene, oral care, other), and behaviors, attitudes, and perceptions of use and safety across sociodemographic factors to evaluate relationships between sociodemographic factors and the total number of products used within the prior 24–48 h using multivariable models. We also summarized participants’ perceptions and attitudes. Among 591 adults (20.0% Asian American/Pacific Islander [AAPI], 5.9% Hispanic, 9.6% non-Hispanic Black [NHB], 54.6% non-Hispanic White [NHW], and 9.9% multiracial or other), the average number of PCPs used within the prior 24–48 h was 15.6 ± 7.7. PCP use was greater among females than males (19.0 vs. 7.9, P \u3c 0.01) and varied by race and ethnicity among females. Relative to NHWs, AAPI females used fewer hair products (2.5 vs. 3.1) and more feminine hygiene products (1.5 vs. 1.1), NHB females used more hair products (3.8 vs. 3.1), perfumes (1.0 vs. 0.6), oral care (2.3 vs. 1.9), and feminine hygiene products (1.8 vs. 1.1), and multiracial or other females used more oral care (2.2 vs. 1.9) and feminine hygiene products (1.5 vs. 1.1) (P-values \u3c0.05). Generally, study participants reported moderate concern about exposures and health effects from using PCPs, with few differences by gender, race, and ethnicity. These findings add to the extant literature on PCP use across sociodemographic characteristics. Improving the understanding of patterns of use for specific products and their chemical ingredients is critical for developing interventions to reduce these exposures, especially in vulnerable groups with an unequal burden of exposure

    Sport in the city: measuring economic significance at the local level

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    In many cities throughout Europe, sport is increasingly being used as a tool for economic revitalisation. While there has been a growth in literature relating to the specific economic impacts of sports-led development, including professional sport facilities, teams, and sport events, limited research has been undertaken on the contribution of the whole sport sector to output and employment. In the United Kingdom (UK), studies have focused on evaluating sport-related economic activity at the national level, yet despite the increasing use of sport for local economic development little research has been undertaken at the city level. To address this situation, this article uses the National Income Accounting framework to measure the economic importance of sport in Sheffield, UK. It shows that the value-added in 1996/97 was 165.61m or 4.11% of Gross Domestic Product (GDP), approximately twice the amount predicted from current national estimates. It is argued that this can primarily be explained by previous studies under-estimating the economic importance of sport, largely due to methodological differences. It goes on to suggest that future research on the significance of sport should be undertaken at the local level to provide policymakers with information at the spatial level where regeneration programmes are being implemented.</p
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