352 research outputs found

    Mori Dream Spaces as fine moduli of quiver representations

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    We construct Mori Dream Spaces as fine moduli spaces of representations of bound quivers, thereby extending results of Craw--Smith \cite{CrawSmith} beyond the toric case. Any collection of effective line bundles L=(OX,L1,...,Lr)\mathscr{L}=(\mathscr{O}_X, L_1,..., L_r) on a Mori Dream Space XX defines a bound quiver of sections and a map from XX to a toric quiver variety ∣L∣|\mathscr{L}| called the multigraded linear series. We provide necessary and sufficient conditions for this map to be a closed immersion and, under additional assumptions on L\mathscr{L}, the image realises XX as the fine moduli space of ϑ\vartheta-stable representations of the bound quiver. As an application, we show how to reconstruct del Pezzo surfaces from a full, strongly exceptional collection of line bundles.Comment: 25 pages, 2 figures; v2 section 3 simplified, typos corrected; v3 final versio

    Researchers\u27, Stakeholders\u27, and Investors\u27 Perceptions of U.S. Stem Cell Research Policy

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    Federal support and funding for human embryonic stem cell (hESC) research in the United States lags behind stem cell programs in many countries because of the divisive debate over hESC research and the continually evolving federal policies that have hindered research efforts. The purpose of this phenomenological study was to explore the perceptions of stem cell researchers, stakeholders, and investors in the United States about the effects of the current federal stem cell policy on stem cell research in the United States, the moral disagreement with stem cell research, and their recommendations to improve stem cell research policy in the United States. Rogers\u27s diffusion of innovation theory and Kingdon\u27s agenda-setting theory served as the theoretical frameworks for this study. Data were collected through telephonic semistructured interviews with a snowball sample of 21 participants. Data were analyzed using Attride-Stirling\u27s 6 steps of thematic coding. Findings indicated the need to educate laypersons and legislators, involve the public in the stem cell research policy debate, increase federal funding, and exclude religious considerations from political discussions. The implications for positive social change are directed at stem cell policymakers to focus attention and resources on creating a cohesive federal hESC funding policy to ensure that stem cell research improves in the United States with the goal of developing treatments for conditions that are currently untreatable

    Adapting and testing a brief intervention to reduce maternal anxiety during pregnancy (ACORN): study protocol for a randomised controlled trial.

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    BACKGROUND: National guidelines in the UK, United States of America, Canada, and Australia have recently stressed the importance of identifying and treating antenatal anxiety and depression. However, there is little research into the most effective and acceptable ways of helping women manage their symptoms of anxiety and stress during pregnancy. Research indicates the necessity to consider the unique needs and concerns of perinatal populations to ensure treatment engagement, highlighting the need to develop specialised treatments which could be integrated within routine antenatal healthcare services. This trial aims to develop a brief intervention for antenatal anxiety, with a focus on embedding the delivery of the treatment within routine antenatal care. METHODS/DESIGN: This study is a two-phase feasibility trial. In phase 1 we will develop and pilot a brief intervention for antenatal anxiety, blended with group support, to be led by midwives. This intervention will draw on cognitive behavioural principles and wider learning from existing interventions that have been used to reduce anxiety in expectant mothers. The intervention will then be tested in a pilot randomised controlled trial in phase 2. The following outcomes will be assessed: (1) number of participants meeting eligibility criteria, (2) number of participants consenting to the study, (3) number of participants randomised, (4) number of sessions completed by those in the intervention arm, and (5) number of participants completing the post-intervention outcome measures. Secondary outcomes comprise: detailed feedback on acceptability, which will guide further development of the intervention; and outcome data on symptoms of maternal and paternal anxiety and depression, maternal quality of life, quality of couple relationship, mother-child bonding, infant temperament and infant sleep. DISCUSSION: The study will provide important data to inform the design of a future full-scale randomised controlled trial of a brief intervention for anxiety during pregnancy. This will include information on its acceptability and feasibility regarding implementation within current antenatal services, which will inform whether ultimately this provision could be rolled out widely in healthcare settings. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95282830 . Registered on 29 October 2014

    Portfolio Vol. IV N 2

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    Mahood, Danner L. War Sonnets. Poetry. 2. Lenser, Eugene. Landscape. Picture. 2. Lay, Mary Virginia. Damned Laughter. Prose. 3-4. Card, Dorothy. They Call It Love. Prose. 5. Kinney, John. Maestro. Prose. 7-9. Anstaett, Joe. Styleglance. Picture. 6. Beckham, Adela. Still the Echo. Poetry. 10. Bridge, Robert. Design for Life. Prose. 11. Seagrave, Dr. Gordon. Letter from Burma. Prose. 12-13. Chin, David K. To know their theatre is to know the Chinese people. Prose. 15. Jones, Charles. The Bookshelf. Prose. 16. Smith, Duke. Keeping the Records Straight. Prose. 17. Beckham, Adela. If Love Could Be. Prose. 19. Raymond, Toby. The Courtship of Miles Standish. Poetry. 20. King, Horace. The Case for Modern Art. Prose. 21-22. Elliot, Frances Gray. Black and White Dancers. Picture. 10

    Anatomy-Aware Self-supervised Fetal MRI Synthesis from Unpaired Ultrasound Images

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    Fetal brain magnetic resonance imaging (MRI) offers exquisite images of the developing brain but is not suitable for anomaly screening. For this ultrasound (US) is employed. While expert sonographers are adept at reading US images, MR images are much easier for non-experts to interpret. Hence in this paper we seek to produce images with MRI-like appearance directly from clinical US images. Our own clinical motivation is to seek a way to communicate US findings to patients or clinical professionals unfamiliar with US, but in medical image analysis such a capability is potentially useful, for instance, for US-MRI registration or fusion. Our model is self-supervised and end-to-end trainable. Specifically, based on an assumption that the US and MRI data share a similar anatomical latent space, we first utilise an extractor to determine shared latent features, which are then used for data synthesis. Since paired data was unavailable for our study (and rare in practice), we propose to enforce the distributions to be similar instead of employing pixel-wise constraints, by adversarial learning in both the image domain and latent space. Furthermore, we propose an adversarial structural constraint to regularise the anatomical structures between the two modalities during the synthesis. A cross-modal attention scheme is proposed to leverage non-local spatial correlations. The feasibility of the approach to produce realistic looking MR images is demonstrated quantitatively and with a qualitative evaluation compared to real fetal MR images.Comment: MICCAI-MLMI 201

    Development of a multi-locus sequence typing scheme for Laribacter hongkongensis, a novel bacterium associated with freshwater fish-borne gastroenteritis and traveler's diarrhea

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    <p>Abstract</p> <p>Background</p> <p>Laribacter hongkongensis is a newly discovered, facultative anaerobic, Gram-negative, motile, sea gull-shaped rod associated with freshwater fish borne gastroenteritis and traveler's diarrhea. A highly reproducible and discriminative typing system is essential for better understanding of the epidemiology of <it>L. hongkongensis</it>. In this study, a multilocus sequence typing (MLST) system was developed for <it>L. hongkongensis</it>. The system was used to characterize 146 <it>L. hongkongensis </it>isolates, including 39 from humans and 107 from fish.</p> <p>Results</p> <p>Fragments (362 to 504 bp) of seven housekeeping genes were amplified and sequenced. Among the 3068 bp of the seven loci, 332 polymorphic sites were observed. The median number of alleles at each locus was 34 [range 22 (<it>ilvC</it>) to 45 (<it>thiC</it>)]. All seven genes showed very low <it>d</it><sub><it>n</it></sub>/<it>d</it><sub><it>s </it></sub>ratios of < 0.04, indicating that no strong positive selective pressure is present. A total of 97 different sequence types (STs) were assigned to the 146 isolates, with 80 STs identified only once. The overall discriminatory power was 0.9861. eBURST grouped the isolates into 12 lineages, with six groups containing only isolates from fish and three groups only isolates from humans. Standardized index of association (<it>I</it><sup><it>S</it></sup><sub><it>A</it></sub>) measurement showed significant linkage disequilibrium in isolates from both humans and fish. The <it>I</it><sup><it>S</it></sup><sub><it>A </it></sub>for the isolates from humans and fish were 0.270 and 0.636, indicating the isolates from fish were more clonal than the isolates from humans. Only one interconnected network (<it>acnB</it>) was detected in the split graphs. The P-value (P = 0) of sum of the squares of condensed fragments in Sawyer's test showed evidence of intragenic recombination in the <it>rho, acnB </it>and <it>thiC </it>loci, but the P-value (P = 1) of maximum condensed fragment in these gene loci did not show evidence of intragenic recombination. Congruence analysis showed that all the pairwise comparisons of the 7 MLST loci were incongruent, indicating that recombination played a substantial role in the evolution of <it>L. hongkongensis</it>. A website for <it>L. hongkongensis </it>MLST was set up and can be accessed at <url>http://mlstdb.hku.hk:14206/MLST_index.html</url>.</p> <p>Conclusion</p> <p>A highly reproducible and discriminative MLST system was developed for <it>L. hongkongensis</it>.</p

    Main motivations for CRM adoption by large portuguese companies: a principal component analysis

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    The motivations for an organization to adopt Customer Relationship Management (CRM) systems can be very varied, which brings an additional complexity to the adoption decision. It is important to understand the main drivers of CRM adoption so that companies can better target their investment efforts. This paper presents and discusses the main findings of a study undertaken among a sample of large Portuguese companies, identifying and discussing the main motivations for CRM systems adoption. A survey was carried out for data collection, and a Principal Component Analysis was made to identify the main motivations. The study concludes that the main motivations for adopting CRM systems are related to cost reduction, improving overall customer satisfaction, improving processes, achieving competitive advantages and improving information quality. The findings of this study can help the academic and professional community to better understand the main motivations of companies for adopting CRM systems, and also for CRM systems vendors and consultants to better address the needs of their potential clients

    Concepts and Measurement in Multimethod Research

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    This article argues that concept misformation and conceptual stretching undermine efforts to combine qualitative and quantitative methods in multimethod research (MMR). Two related problems result from the mismatch of qualitatively and quantitatively construed concepts. Mechanism muddling occurs when differences in the connotation of qualitatively and quantitatively construed concepts embed different causal properties into conceptual definitions. Conceptual slippage occurs when qualitatively and quantitatively construed concepts use incompatible nominal, ordinal, or radial scales. Instead of gaining leverage from the synthesis of large- and small-N analysis, these problems can push MMR in two diametrically opposed directions, emphasizing one methodological facet at the cost of the other.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
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