Generalized Satisfiability Problems via Operator Assignments

Schaefer introduced a framework for generalized satisfiability problems on the Boolean domain and characterized the computational complexity of such problems. We investigate an algebraization of Schaefer's framework in which the Fourier transform is used to represent constraints by multilinear polynomials in a unique way. The polynomial representation of constraints gives rise to a relaxation of the notion of satisfiability in which the values to variables are linear operators on some Hilbert space. For the case of constraints given by a system of linear equations over the two-element field, this relaxation has received considerable attention in the foundations of quantum mechanics, where such constructions as the Mermin-Peres magic square show that there are systems that have no solutions in the Boolean domain, but have solutions via operator assignments on some finite-dimensional Hilbert space. We obtain a complete characterization of the classes of Boolean relations for which there is a gap between satisfiability in the Boolean domain and the relaxation of satisfiability via operator assignments. To establish our main result, we adapt the notion of primitive-positive definability (pp-definability) to our setting, a notion that has been used extensively in the study of constraint satisfaction problems. Here, we show that pp-definability gives rise to gadget reductions that preserve satisfiability gaps. We also present several additional applications of this method. In particular and perhaps surprisingly, we show that the relaxed notion of pp-definability in which the quantified variables are allowed to range over operator assignments gives no additional expressive power in defining Boolean relations

Design, fabrication and test of integrated micro-scale vibration based electromagnetic generator

This paper discusses the design, fabrication and testing of electromagnetic microgenerators. Three different designs of power generators are partially microfabricated and assembled. Prototype A having a wire-wound copper coil, Prototype B, an electrodeposited copper coil both on a Deep Reactive Ion etched (DRIE) silicon, beam and paddle. Prototype C uses moving NdFeB magnets in between two microfabricated coils. The integrated coil, paddle and beam were fabricated using standard micro-Electro-Mechanical Systems (MEMS) processing techniques. For Prototype A, the maximum measured power output was 148 nW at 8.08 kHz resonant frequency and 3.9 m/s2 acceleration. For prototype B, the microgenerator gave a maximum load power of 23 nW for an acceleration of 9.8 m/s2, at a resonant frequency of 9.83 kHz. This is a substantial improvement in power generated over other microfabricated silicon based generators reported in literature. This generator has a volume of 0.1 cm3 which is lowest of all the silicon based microfabricated electromagnetic power generators reported. To verify the potential of integrated coils in electromagnetic generators, Prototype C was assembled. This generated a maximum load power of 5

Potential Models for Radiative Rare B Decays

We compute the branching ratios for the radiative rare decays of B into K-Meson states and compare them to the experimentally determined branching ratio for inclusive decay b -> s gamma using non relativistic quark model, and form factor definitions consistent with HQET covariant trace formalism. Such calculations necessarily involve a potential model. In order to test the sensitivity of calculations to potential models we have used three different potentials, namely linear potential, screening confining potential and heavy quark potential as it stands in QCD.We find the branching ratios relative to the inclusive b ->s gamma decay to be (16.07\pm 5.2)% for B -> K^* (892)gamma and (7.25\pm 3.2)% for B -> K_2^* (1430)gamma for linear potential. In the case of the screening confining potential these values are (19.75\pm 5.3)% and (4.74\pm 1.2)% while those for the heavy quark potential are (11.18\pm 4.6)% and (5.09\pm 2.7)% respectively. All these values are consistent with the corresponding present CLEO experimental values: (16.25\pm 1.21)% and (5.93\pm 0.46)%.Comment: RevTeX, 6 pages, 1 eps figur

Is the Health and Wellbeing of University Students Associated with their Academic Performance? Cross Sectional Findings from the United Kingdom

This study explored the associations between health awareness, health behaviour, subjective health status, and satisfaction of students with their educational experience as independent variables and three outcomes of educational achievement as dependent variables. We undertook two simultaneous cross-sectional surveys among students from one University in the UK during 2008−2009. The first survey was a general health survey; the second survey measured students’ satisfaction with different aspects of their learning and teaching experience. Students’ registration numbers linked the responses of both questionnaires together, and subsequently linked the questionnaires to the university database to import the grades that students actually achieved in their studies. Generally, on average, students (N = 380) exhibited medium to high satisfaction with their educational experiences. In the multivariate regression analyses, students’ satisfaction with their educational experiences was not associated with any of the three indicators of educational achievement (actual module mark; perceived own performance; importance of achieving good grades). The associations of educational satisfaction, health, health behaviours, heath complaints and financial parameters with the three outcomes of educational achievement did not differ between male and female students. Each of the health, health behaviours, health complaints and financial parameters were selectively associated with only some but not all three indicators of student educational achievement. We conclude that the findings support a conceptual framework suggesting reciprocal relationships between health, health behaviour and educational achievement. Comprehensive health promotion programmes may have the potential to influence relevant predictors of educational achievement in university students

Shifting journalistic roles in democratic transitions: Lessons from Egypt

While in the case of the Arab Spring the focus of research and debate was very much on the role of social media in enabling political change both during the uprisings and in their immediate aftermath, the impact of traditional national mass media and journalism on framing this political change has been less addressed. In this article, we investigate the role of Egyptian journalists in shaping Egypt’s complex and fast-moving political transition. Based on a thematic analysis of in-depth interviews and a conceptual framework building on Christians et al.’s normative roles of the media, it can be concluded that the monitorial and facilitative roles, which were prevalent in the early stages of the post-Mubarak era, were quickly overturned in favor of a radical and collaborative role. Egyptian journalists working in private media thus demonized their political adversaries, mainly the Islamists, transforming this political ‘other’ into the ultimate enemy. At the same time, the new military regime was being revered and celebrated. This arguably contributed to further destabilize the fragile transition to democracy. It is furthermore concluded that for democracy to succeed in an Egyptian context, antagonistic political conflicts need to be transformed into agonistic ones both at the level of political culture and media culture

Airway Clearance Techniques for Primary Ciliary Dyskinesia; is the Cystic Fibrosis literature portable?

Primary Ciliary Dyskinesia (PCD) is a rare inherited disease with impaired mucociliary clearance. Airway clearance techniques (ACTs) are commonly recommended for patients with PCD to facilitate mucus clearance, despite a lack of evidence in this group. Current physiotherapy practice in PCD is based on evidence extrapolated from the field of Cystic Fibrosis (CF). This paper focuses on the available evidence and outlines challenges in extrapolating evidence between the conditions for best clinical practice

A novel class of microRNA-recognition elements that function only within open reading frames.

MicroRNAs (miRNAs) are well known to target 3' untranslated regions (3' UTRs) in mRNAs, thereby silencing gene expression at the post-transcriptional level. Multiple reports have also indicated the ability of miRNAs to target protein-coding sequences (CDS); however, miRNAs have been generally believed to function through similar mechanisms regardless of the locations of their sites of action. Here, we report a class of miRNA-recognition elements (MREs) that function exclusively in CDS regions. Through functional and mechanistic characterization of these 'unusual' MREs, we demonstrate that CDS-targeted miRNAs require extensive base-pairing at the 3' side rather than the 5' seed; cause gene silencing in an Argonaute-dependent but GW182-independent manner; and repress translation by inducing transient ribosome stalling instead of mRNA destabilization. These findings reveal distinct mechanisms and functional consequences of miRNAs that target CDS versus the 3' UTR and suggest that CDS-targeted miRNAs may use a translational quality-control-related mechanism to regulate translation in mammalian cells

The influence of soft contact lens wear and two weeks cessation of lens wear on corneal curvature.

INTRODUCTION: Accurate corneal measurements are crucial in corneal refractive surgery (CRS) to ensure successful outcomes. Soft contact lens (SCL) wear may result in changes to corneal curvature and structure. United States Food and Drug Administration (FDA) pre-operative guidelines recommend that prior to CRS, SCL wearers cease SCL wear for "at least two weeks before examination and treatment" [1]. Corneal curvature changes induced by SCL wear may take longer than two weeks to resolve. PURPOSE: To examine the effect of SCL wear on corneal curvature before and following two weeks SCL wear cessation. To explore the possible impact of different SCL materials and years of SCL wear. METHODS: Retrospective data analysis, between a group of SCL wearers (SCL: n=45); and a non-contact lens control group (NCL: n=45). Corneal curvature parameters were measured using the Pentacam (Oculus, Germany), before and following two weeks cessation of SCL wear. RESULTS: No significant differences in keratometry or Sagittal radius of curvature between SCL and NCL groups prior to or following SCL cessation. Tangential radius of curvature showed significant inferior steepening for the SCL group prior to SCL cessation (SCL vs. NCL; 7.77±0.30mm vs. 7.90±0.30mm; p=0.04). Following two weeks cessation of SCL wear this appeared to have resolved. CONCLUSIONS: Two weeks cessation of SCL wear appears sufficient for resolution of corneal curvature changes with modern SCL materials and years of SCL wear. However, further studies with longer lens deprivation periods are required to ensure stability for all SCL wearing patients

Stroke secondary prevention, a non-surgical and non-pharmacological consensus definition : results of a Delphi study

OBJECTIVE: Evidence supporting lifestyle modification in vascular risk reduction is limited, drawn largely from primary prevention studies. To advance the evidence base for non-pharmacological and non-surgical stroke secondary prevention (SSP), empirical research is needed, informed by a consensus-derived definition of SSP. To date, no such definition has been published. We used Delphi methods to generate an evidence-based definition of non-pharmacological and non-surgical SSP. RESULTS: The 16 participants were members of INSsPiRE (International Network of Stroke Secondary Prevention Researchers), a multidisciplinary group of trialists, academics and clinicians. The Elicitation stage identified 49 key elements, grouped into 3 overarching domains: Risk factors, Education, and Theory before being subjected to iterative stages of elicitation, ranking, discussion, and anonymous voting. In the Action stage, following an experience-based engagement with key stakeholders, a consensus-derived definition, complementing current pharmacological and surgical SSP pathways, was finalised: Non-pharmacological and non-surgical stroke secondary prevention supports and improves long-term health and well-being in everyday life and reduces the risk of another stroke, by drawing from a spectrum of theoretically informed interventions and educational strategies. Interventions to self-manage modifiable lifestyle risk factors are contextualized and individualized to the capacities, needs, and personally meaningful priorities of individuals with stroke and their families