564 research outputs found
Propagation-invariant beams with quantum pendulum spectra: from Bessel beams to Gaussian beam-beams
We describe a new class of propagation-invariant light beams with Fourier
transform given by an eigenfunction of the quantum mechanical pendulum. These
beams, whose spectra (restricted to a circle) are doubly-periodic Mathieu
functions in azimuth, depend on a field strength parameter. When the parameter
is zero, pendulum beams are Bessel beams, and as the parameter approaches
infinity, they resemble transversely propagating one-dimensional Gaussian
wavepackets (Gaussian beam-beams). Pendulum beams are the eigenfunctions of an
operator which interpolates between the squared angular momentum operator and
the linear momentum operator. The analysis reveals connections with Mathieu
beams, and insight into the paraxial approximation.Comment: 4 pages, 3 figures, Optics Letters styl
The field of inter-organizational relations : a jungle or an Italian garden?
Each chapter in this Handbook contains an explicit assessment of priorities for future research that would extend and deepen an understanding of IOR. Given the diversity of contributions to this volume, it is perhaps not surprising that recommendations for future research are varied. And because the three sets of contributions start from different points-empirical manifestations, theoretical and disciplinary perspectives, and thematic interests-so the recommendations, too, might be expected to lead along different paths, 'cutting' and framing future research topics in different ways. Nevertheless, as others have suggested (Brass et al. 2005) it is possible to see some points of convergence across all three parts of the Handbook. We begin our discussion of the contributions and suggestions for the future by focusing on these points of convergence. We then look in turn at the specific ideas that emerge from, and relate to, the specific framings of each of the parts. Finally, we draw together insights about methodological issues
The association between life events, social support, and antibody status following thymus-dependent and thymus-independent vaccinations in healthy young adults
This study determined whether stressful life events and social support were related to antibody status following both thymus-dependent and thymus-independent vaccinations. Life events in the previous year and customary social support were measured in 57 healthy students at baseline. Antibody status was also assessed at baseline and at five weeks and five months following vaccination with the trivalent influenza vaccine and the meningococcal A+C polysaccharide vaccine. Taking into account baseline antibody titre, high life events scores prior to vaccination were associated with lower responses to the B/Shangdong influenza strain at both five weeks and five months and meningococcal C at five weeks. Life events scores were not associated with response to the other two influenza viral strains nor response to meningococcal A. Those with high social support scores had stronger 5-week and 5-month antibody responses to the A/Panama influenza strain, but not to any of the other strains. These associations could not be accounted for by demographic or health behaviour factors, and also emerged from analyses comparing those who exhibited a four-fold increase in antibody titre from baseline with those who did not. Life events and social support were related to antibody status following influenza vaccination in distinctive ways that may be partly determined by vaccine novelty and prior naturalistic exposure. Life events also predicted poor antibody response to meningococcal C polysaccharide vaccination after previous meningococcal C conjugate vaccination. Neither psychosocial factor was associated with response to primary meningococcal A polysaccharide vaccination
Perfect Function Transfer in two- and three- dimensions without initialization
We find analytic models that can perfectly transfer, without state
initializati$ or remote collaboration, arbitrary functions in two- and
three-dimensional interacting bosonic and fermionic networks. We elaborate on a
possible implementation of state transfer through bosonic or fermionic atoms
trapped in optical lattices. A significant finding is that the state of a spin
qubit can be perfectly transferred through a fermionic system. Families of
Hamiltonians, both linear and nonlinear, are described which are related to the
linear Boson model and that enable the perfect transfer of arbitrary functions.
This includes entangled states such as decoherence-free subsystems enabling
noise protection of the transferred state.Comment: 4 pages, no figur
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Autistic characteristics in adults with epilepsy and perceived seizure activity.
UNLABELLED: The prevalence of autism spectrum disorders in epilepsy is approximately 15%-47%, with previous research by Wakeford and colleagues reporting higher autistic traits in adults with epilepsy. The aim of this study was to investigate autistic characteristics and their relationship to having seizures by employing two behavioral assessments in two samples: adults with epilepsy and controls. METHOD: The study employed the Social Responsiveness Scale - Shortened (SRS-S) (patients with epilepsy (n=76), control (n=19)) and the brief Repetitive Behavior Scale - Revised (RBS-R) (patients with epilepsy (n=47), control (n=21)). This study employed a unique method to quantify the extent to which autistic characteristics are related to perceived mild seizure activity. Adults with epilepsy were instructed to rate their usual behavior on each assessment and, at the same time, rate their behavior again when they perceived that they were having mild seizure activity. RESULTS: Significantly higher SRS-S scores were related to having a diagnosis of epilepsy and were perceived by adults with epilepsy to increase during mild seizure activity. These scores positively correlated with antiepileptic drug control. No difference was found for RBS-R scores in adults with epilepsy compared with controls. CONCLUSION: Together, these results suggest that adults with epilepsy have higher autistic characteristics measured by the social responsiveness scale, while sameness behaviors remain unimpaired. The autistic characteristics measured by the social responsiveness scale were reported by adults with epilepsy to be more severe during their mild seizure activity.The authors would like to thank Epilepsy Action for the non-financial support of this research.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.yebeh.2015.08.03
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A method for identifying associations between seizures and possible trigger events in adults with intellectual disability.
OBJECTIVES: Precipitants of seizures are often reported by patients and carers, but the accuracy of these claims remains unknown. Focusing on epilepsy in people with intellectual disability (ID), the aims of this work were to (1) identify a set of methods for assessing the validity of reported seizure triggers in individual patients; and (2) undertake an initial assessment of the ease of implementation and acceptability of the method by applying it to a series of cases. METHODS: Data collection materials (developed with carer involvement) consisted primarily of carer diaries of seizure and trigger occurrences. Statistical analysis of diary data was using the self-controlled case series method. Unlike previously used methods, the analysis method included a means of choosing the time window, following trigger exposure, during which changes in seizure likelihood are to be assessed. RESULTS: The method developed was trialed in five adults with ID and epilepsy, who had a range of ID severities and living circumstances. Examples of the application of the method in two of the five cases are presented for illustrative purposes. The method was acceptable to participants and most aspects successfully implemented. SIGNIFICANCE: This method may be useful for clinicians and researchers wishing to investigate possible triggers in individual patients with epilepsy and ID. It also supports the identification of a statistically defined time window following exposure to a precipitant, during which the risk of developing a seizure is increased. The identification of such a window has value not just in contributing to clinical management, but also in guiding future work into the mechanisms of seizure precipitation.This study was funded by a grant to HR from Epilepsy Action: The Epilepsy Association. (Registered Charity in England (No. 234343)). SX was supported by NIH/NCRR Colorado CTSI Grant Number UL1 RR025780. HR is a member of the NIHRās Collaboration for Leadership in Applied Health Research and Care (CLAHRC) East of England at Cambridgeshire & Peterborough NHS Foundation Trust. JI also received funding from CLAHRC East of England during preparation of the manuscript. This article presents independent research with funding from the National Institute for Health Research (NIHR). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health (UK). We would also like to thank Elizabeth Blake-Palmer for her assistance with patient recruitment, and Professor Paddy Farrington for statistical advice.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/epi.1313
Minding the gap: The importance of active facilitation in moving boundary objects from in-theory to in-use as a tool for knowledge mobilisation
The Health Inequalities Assessment Toolkit (HIAT) was developed to support those involved in health research to integrate a focus on health inequalities. Our study focuses on bringing together the concepts of boundary objects (BO) and brokers-as-bricoleurs to explain the implementation of the HIAT within a research capacity building programme. Exploring the extent to which (i) the HIAT operated as a BO and (ii) the ideal conditions to nurture and enhance its effectiveness during knowledge mobilisation. We employed a qualitative approach to analyse: semi-structured focus groups and telephone interviews; secondary data from an evaluation of the wider research programme within which the capacity building was situated. Data was thematically analysed incorporating the properties of a BO: meaningfulness, convergence, resonance and authenticity. Four main themes identified: (1) Generating convergence through creating a focus (2) Reconciling differences to create a common language (3) Workshop facilitators: boundary brokers-as-bricoleurs, (4) Thoughts into action. The HIAT operated as a BO, enabling individuals across the different project teams to galvanise around the issue of health inequalities, explore collaboratively and incorporate equity within service evaluations. Highlighting the importance of involving brokers with an ability to improvise and mobilise around the HIAT, using their expertise to translate and interpret across boundaries and emphasise shared goals. Reflecting on this, a modified tool with additional resources beyond socio-economic causes has been launched as a forum to consider health inequalities from diverse perspectives for use beyond UK health and social care research
The health impacts of women's low control in their living environment: A theory-based systematic review of observational studies in societies with profound gender discrimination.
We conducted a systematic review of observational evidence on the health impacts of women's low control/autonomy in the living environment in societies with profound gender discrimination and gender bias. Thirty observational studies of varying methodological quality were included. Overall, the evidence suggests that women's lower control or autonomy (for example lack of freedom of movement outside the home, lack of authority to access healthcare for sick children) was associated with poorer mental and physical health for women and higher morbidity and mortality for their children, after adjusting for their socioeconomic circumstances. Further studies are needed to disentangle and understand the pathways between low control and health outcomes in contexts of profound gender discrimination. This systematic review has highlighted the general low quality of the evidence base on this research question. It identifies the pressing need for high quality, longitudinal studies in the future
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