103 research outputs found

    The Statistical Analysis of Roll Call

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    We develop a Bayesian estimation procedure for spatial models of roll call voting. We show how a Bayesian approach to roll call analysis overcomes shortcomings and idiosyncracies of NOMINATE (some of which are not widely recognized). Our Bayesian approach (a) applies to any legislative setting, irrespective of size, legislative extremism, or the number of roll calls available for analysis; (b) provides a mechanism for directly incorporating auxiliary information as to the dimensionality of the underlying policy space, the identity of extremist legislators, key votes and the evolution of the legislative agenda; (c) lets us integrate measurement of legislative preferences with the analysis of those preferences. Notes to NEMP, May 2002 This paper sets out our ‘‘basic setup’ ’ (a Bayesian statistical operationalization of the Euclidean spatial voting model with roll call data), and constrasts it with the NOMINATE algorithms of Poole and Rosenthal. In the talk I will be considering extensions to our model, so as to accommodate and/or test conjectures in the literature on legislative politics (most prominently, the ‘‘party discipline’ ’ hypothesis, and conjectures about legislative responsiveness to constituency interests)

    2011 Report of NSF Workshop Series on Scientific Software Security Innovation Institute

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    Over the period of 2010-2011, a series of two workshops were held in response to NSF Dear Colleague Letter NSF 10-050 calling for exploratory workshops to consider requirements for Scientific Software Innovation Institutes (S2I2s). The specific topic of the workshop series was the potential benefits of a security-focused software institute that would serve the entire NSF research and development community. The first workshop was held on August 6th, 2010 in Arlington, VA and represented an initial exploration of the topic. The second workshop was held on October 26th, 2011 in Chicago, IL and its goals were to 1) Extend our understanding of relevant needs of MREFC and large NSF Projects, 2) refine outcome from first workshop with broader community input, and 3) vet concepts for a trusted cyberinfrastructure institute. Towards those goals, the participants other 2011workshop included greater representation from MREFC and large NSF projects, and, for the most part, did not overlap with the participants from the 2010 workshop. A highlight of the second workshop was, at the invitation of the organizers, a presentation by Scott Koranda of the LIGO project on the history of LIGO’s identity management activities and how those could have benefited from a security institute. A key analysis he presented is that, by his estimation, LIGO could have saved 2 senior FTE-years of effort by following suitable expert guidance had it existed. The overarching finding from the workshops is that security is a critical crosscutting issue for the NSF software infrastructure and recommended a security focused activity to address this issue broadly, for example a security software institute (S2I2) under the SI2 program. Additionally, the 2010 workshop participants agreed to 15 key additional findings, which the 2011 workshop confirmed, with some refinement as discussed in this report.NSF Grant # 1043843Ope

    A feasibility study exploring the role of pre-operative assessment when examining the mechanism of ‘chemo-brain’ in breast cancer patients

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    Background: Women receiving chemotherapy treatment for breast cancer may experience problems with their memory and attention (cognition), which is distressing and interferes with quality of life. It is unclear what causes or contributes to the problems they report: psychological distress, fatigue, coping style, or specific biological changes for example to pro inflammatory cytokines. Research shows however, that approximately a third of women with breast cancer perform poorly on tests of cognition before commencing chemotherapy. We aimed to examine the acceptability and relevance of pre-surgical assessments (bloods, brain imaging, cognitive tests and self-report questionnaires) when investigating the phenomenon of ‘chemo-brain’ and investigate whether inflammatory markers mediate chemotherapy-induced neuropsychological impairments in women treated for breast cancer. Methods: Women with early stage breast cancer completed neuropsychological and quality of life assessments at T1 (pre-surgery), T2 (post-surgery before chemotherapy) and T3 (6 months later). Blood cytokine levels were measured at the same time points and brain imaging was performed at T1 and T3. Results: In total, 14/58 women participated (8 chemotherapy, 6 non-chemotherapy). Prior to the start of chemotherapy a decline in cognitive performance compared to baseline was observed in one participant. At T3 women who received chemotherapy reported poorer quality of life and greater fatigue. Increases in soluble tumour necrosis factor receptor II (sTNFRII), interleukin-6, interleukin-10 and vascular endothelial growth factor occurred post chemotherapy only. Levels of sTNFRII were inversely correlated with grey matter volume (GMV) of the right posterior insula in both groups. At T3, the chemotherapy group displayed a greater reduction in GMV in the subgenual and dorsal anterior cingulate, and the inferior temporal gyrus. Conclusions: Pre-operative recruitment to the study was challenging; however, the lack of significant changes in blood cytokine levels and neuropsychological tests at T2 implies that post surgery may be a valid baseline assessment, but this needs further investigation in a larger study. The preliminary results support the hypothesis that chemotherapy induced fatigue is mediated by a change in peripheral cytokine levels which could explain some symptoms of ‘chemo brain’ experienced by patients

    Genetic improvement of tomato by targeted control of fruit softening

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    Controlling the rate of softening to extend shelf life was a key target for researchers engineering genetically modified (GM) tomatoes in the 1990s, but only modest improvements were achieved. Hybrids grown nowadays contain 'non-ripening mutations' that slow ripening and improve shelf life, but adversely affect flavor and color. We report substantial, targeted control of tomato softening, without affecting other aspects of ripening, by silencing a gene encoding a pectate lyase

    A novel ESR2 frameshift mutation predisposes to medullary thyroid carcinoma and causes inappropriate RET expression

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