Signal and System Approximation from General Measurements

In this paper we analyze the behavior of system approximation processes for stable linear time-invariant (LTI) systems and signals in the Paley-Wiener space PW_\pi^1. We consider approximation processes, where the input signal is not directly used to generate the system output, but instead a sequence of numbers is used that is generated from the input signal by measurement functionals. We consider classical sampling which corresponds to a pointwise evaluation of the signal, as well as several more general measurement functionals. We show that a stable system approximation is not possible for pointwise sampling, because there exist signals and systems such that the approximation process diverges. This remains true even with oversampling. However, if more general measurement functionals are considered, a stable approximation is possible if oversampling is used. Further, we show that without oversampling we have divergence for a large class of practically relevant measurement procedures.Comment: This paper will be published as part of the book "New Perspectives on Approximation and Sampling Theory - Festschrift in honor of Paul Butzer's 85th birthday" in the Applied and Numerical Harmonic Analysis Series, Birkhauser (Springer-Verlag). Parts of this work have been presented at the IEEE International Conference on Acoustics, Speech, and Signal Processing 2014 (ICASSP 2014

Autocalibration with the Minimum Number of Cameras with Known Pixel Shape

In 3D reconstruction, the recovery of the calibration parameters of the cameras is paramount since it provides metric information about the observed scene, e.g., measures of angles and ratios of distances. Autocalibration enables the estimation of the camera parameters without using a calibration device, but by enforcing simple constraints on the camera parameters. In the absence of information about the internal camera parameters such as the focal length and the principal point, the knowledge of the camera pixel shape is usually the only available constraint. Given a projective reconstruction of a rigid scene, we address the problem of the autocalibration of a minimal set of cameras with known pixel shape and otherwise arbitrarily varying intrinsic and extrinsic parameters. We propose an algorithm that only requires 5 cameras (the theoretical minimum), thus halving the number of cameras required by previous algorithms based on the same constraint. To this purpose, we introduce as our basic geometric tool the six-line conic variety (SLCV), consisting in the set of planes intersecting six given lines of 3D space in points of a conic. We show that the set of solutions of the Euclidean upgrading problem for three cameras with known pixel shape can be parameterized in a computationally efficient way. This parameterization is then used to solve autocalibration from five or more cameras, reducing the three-dimensional search space to a two-dimensional one. We provide experiments with real images showing the good performance of the technique.Comment: 19 pages, 14 figures, 7 tables, J. Math. Imaging Vi

Women, men and coronary heart disease: a review of the qualitative literature

Aim. This paper presents a review of the qualitative literature which examines the experiences of patients with coronary heart disease. The paper also assesses whether the experiences of both female and male patients are reflected in the literature and summarizes key themes. Background. Understanding patients' experiences of their illness is important for coronary heart disease prevention and education. Qualitative methods are particularly suited to eliciting patients' detailed understandings and perceptions of illness. As much previous research has been 'gender neutral', this review pays particular attention to gender. Methods. Published papers from 60 qualitative studies were identified for the review through searches in MEDLINE, EMBASE, CINAHL, PREMEDLINE, PsychINFO, Social Sciences Citation Index and Web of Science using keywords related to coronary heart disease. Findings. Early qualitative studies of patients with coronary heart disease were conducted almost exclusively with men, and tended to generalize from 'male' experience to 'human' experience. By the late 1990s this pattern had changed, with the majority of studies including women and many being conducted with solely female samples. However, many studies that include both male and female coronary heart disease patients still do not have a specific gender focus. Key themes in the literature include interpreting symptoms and seeking help, belief about coronary 'candidates' and relationships with health professionals. The influence of social roles is important: many female patients have difficulties reconciling family responsibilities and medical advice, while male patients worry about being absent from work. Conclusions. There is a need for studies that compare the experiences of men and women. There is also an urgent need for work that takes masculinity and gender roles into account when exploring the experiences of men with coronary heart disease

BICCO-Net II. Final report to the Biological Impacts of Climate Change Observation Network (BICCO-Net) Steering Group

• BICCO-Net Phase II presents the most comprehensive single assessment of climate change impacts on UK biodiversity to date. • The results provide a valuable resource for the CCRA 2018, future LWEC report cards, the National Adaptation Programme and other policy-relevant initiatives linked to climate change impacts on biodiversity

Conductance behavior of tetraphenyl-Aza-Bodipys

We studied the electrical conductance of single-molecule junctions formed from molecular wires with four anchor groups. Three tetraphenyl-aza-BODIPYs with four or two thiomethyl anchor groups were synthesized, and their single-molecule conductance was measured using break-junction-STM. Using DFT based calculations these compounds were shown to display a combination of a high and low conductance, depending on the molecule's connectivity in the junction. A scissor correction is employed to obtain the corrected HOMO-LUMO gaps and a tight binding model (TBM) is used to highlight the role of transport through the pi system of the tetraphenyl-aza-BODIPY central unit. The three higher-conductance geometries follow the sequence 3 > 4 > 2, which demonstrates that their conductances are correlated with the number of anchors

A systematic review of techniques and effects of self-help interventions for tinnitus: application of taxonomies from health psychology

Objective: Self-help interventions are followed by people independently with minimal or no therapist contact. This review aims to assess the effectiveness of self-help interventions for adults with chronic tinnitus and systematically identify the self-help techniques used. Design: Systematic review and application of health psychology taxonomies. Electronic database searches were conducted, supplemented by citation searching and hand-searching of key journals. Prospective controlled trials, which used measures of tinnitus distress, functional management, anxiety, depression, and quality of life, were included. Michie et al’s behaviour change techniques (BCTs) taxonomy and Taylor et al’s PRISMS taxonomy of self-management components were applied to describe interventions. Study sample: Five studies were included, providing low-to-moderate levels of evidence. Results: Randomized controlled trial studies were too few and heterogeneous for meta-analysis to be performed. Studies comparing self-help interventions to therapist-guided interventions and assessing non tinnitus-specific psychosocial outcomes and functional management were lacking. Fifteen BCTs and eight self-management components were identified across interventions. Conclusions: A lack of high-quality and homogeneous studies meant that confident conclusions could not be drawn regarding the efficacy of self-help interventions for tinnitus. Better reporting and categorization of intervention techniques is needed for replication in research and practice and to facilitate understanding of intervention mechanisms

Scale-free static and dynamical correlations in melts of monodisperse and Flory-distributed homopolymers: A review of recent bond-fluctuation model studies

It has been assumed until very recently that all long-range correlations are screened in three-dimensional melts of linear homopolymers on distances beyond the correlation length $\xi$ characterizing the decay of the density fluctuations. Summarizing simulation results obtained by means of a variant of the bond-fluctuation model with finite monomer excluded volume interactions and topology violating local and global Monte Carlo moves, we show that due to an interplay of the chain connectivity and the incompressibility constraint, both static and dynamical correlations arise on distances $r \gg \xi$. These correlations are scale-free and, surprisingly, do not depend explicitly on the compressibility of the solution. Both monodisperse and (essentially) Flory-distributed equilibrium polymers are considered.Comment: 60 pages, 49 figure

Radiotherapy exposure directly damages the uterus and causes pregnancy loss

Female cancer survivors are significantly more likely to experience infertility than the general population. It is well established that chemotherapy and radiotherapy can damage the ovary and compromise fertility, yet the ability of cancer treatments to induce uterine damage, and the underlying mechanisms, have been understudied. Here, we show that in mice total-body γ-irradiation (TBI) induced extensive DNA damage and apoptosis in uterine cells. We then transferred healthy donor embryos into ovariectomized adolescent female mice that were previously exposed to TBI to study the impacts of radiotherapy on the uterus independent from effects to ovarian endocrine function. Following TBI, embryo attachment and implantation were unaffected, but fetal resorption was evident at midgestation in 100% of dams, suggesting failed placental development. Consistent with this hypothesis, TBI impaired the decidual response in mice and primary human endometrial stromal cells. TBI also caused uterine artery endothelial dysfunction, likely preventing adequate blood vessel remodeling in early pregnancy. Notably, when pro-apoptotic protein Puma-deficient (Puma–/–) mice were exposed to TBI, apoptosis within the uterus was prevented, and decidualization, vascular function, and pregnancy were restored, identifying PUMA-mediated apoptosis as a key mechanism. Collectively, these data show that TBI damages the uterus and compromises pregnancy success, suggesting that optimal fertility preservation during radiotherapy may require protection of both the ovaries and uterus. In this regard, inhibition of PUMA may represent a potential fertility preservation strategy.Meaghan J. Griffiths, Sarah A. Marshall, Fiona L. Cousins, Lauren R. Alesi, Jordan Higgins, Saranya Giridharan, Urooza C. Sarma, Ellen Menkhorst, Wei Zhou, Alison S. Care, Jacqueline F. Donoghue, Sarah J. Holdsworth-Carson, Peter A.W. Rogers, Evdokia Dimitriadis, Caroline E. Gargett, Sarah A. Robertson, Amy L. Winship, and Karla J. Hut