Robustness of Planar Fourier Capture Arrays to Colour Changes and Lost Pixels

Planar Fourier capture arrays (PFCAs) are optical sensors built entirely in standard microchip manufacturing flows. PFCAs are composed of ensembles of angle sensitive pixels (ASPs) that each report a single coefficient of the Fourier transform of the far-away scene. Here we characterize the performance of PFCAs under the following three non-optimal conditions. First, we show that PFCAs can operate while sensing light of a wavelength other than the design point. Second, if only a randomly-selected subset of 10% of the ASPs are functional, we can nonetheless reconstruct the entire far-away scene using compressed sensing. Third, if the wavelength of the imaged light is unknown, it can be inferred by demanding self-consistency of the outputs.Comment: 15 pages including cover page, 12 figures, associated with the 9th International Conference on Position Sensitive Detector

Anti-inflammatory and combined antiinflammatory/ analgesic medication in the early management of iliotibial band friction syndrome A clinical trial

Forty-three athletes presenting with unilateral iliotibial band friction syndrome (ITBFS) were randomly divided into three groups for the first 7 days of treatment (placebo-controlled, double-blind): 1 - placebo (N = 13); 2 - anti-inflammatory medication (N = 14) (Voharen; Geigy); and 3 - analgesicl anti-inflammatory combined medication (N =. 16) (Myprodol; Rio Ethicals). All subjects rested from day 0 to day 7 and all groups received the same physiotherapy outpatient treatment programme from day 3 to day 7. On days 0, 3 and 7 the subjects performed a functional treadmill running test (maximum 30 minutes) during which they reported pain (scale 0-10; 0 = no pain, 10 = unbearable pain) each minute. Total running distance, total running time and the area under the pain v. time curve was calculated. Daily 24-hour recall pain scores were also recorded. The 24-hour recall pain scores decreased significantly for all the groups over the treatment period. This method of assessing efficacy of treatment therefore failed to show differences between groups. In contrast, during the running test only group 3 improved their total running time and distance from day 0 to day 7, whereas in all the groups the area under the pain v. time curve decreased from day 0 to day 7. All the other groups improved total running time and running distance from day 3 to day 7. All three treatment modalities are effective in the early. treatment of ITBFS but physiotherapy in combination with analgesicl anti-inflammatory medication is superior. A functional running test, which is more sensitive than conventional pain-recall· methods in assessing efficacy of treatment in this type of clinical trial, is described

The relationship between sigmoidal intramucosal pH and intestinal arterial occlusion during aortic reconstructive surgery

Objectives:To investigate the effects of perioperative occlusion of intestinal arteries on clinical outcome and changes in sigmoidal intramuscular pH (pHi). To determine the value of sigmoidal pHi measurement in predicting ischaemic colitis after aortic reconstructive surgery.Design:Prospective, non-selective, open study.Materials:Forty patients undergoing elective aortic infrarenal surgery were monitored with pHi. Pre- and postoperative digital venous subtraction angiography was combined with operative data to evaluate perioperative occlusion of intestinal arteries.Results:All patients had a significant (p < 0.05) drop in pHi after aortic clamping which returned to baseline 2–4 h after declamping. None of the patients had clinical signs of ischaemic colitis postoperatively. All patients had angiographically proven, patent superior mesenteric arteries pre- and postoperatively. Patients were divided into three groups: patients with no changes in intestinal arteries (n = 13), patients with perioperative occlusion of the inferior mesenteric artery (n = 22) and patients with perioperative occlusion of the inferior mesenteric and one or both iliac arteries (n = 5); there were no significant differences in pHi values between the groups.Conclusions:Return of the sigmoidal pHi to baseline values within 6–12 h after declamping probably predicts a postoperative course without ischaemic colitis. Perioperative occlusion of the inferior mesenteric artery alone, or in combination with occlusion of one or both internal iliac arteries, does not cause ischaemic colitis in patients whose sigmoidal pHi rises after declamping

Emergency care provision for, and psychological distress in, survivors of domestic violence

Background This study aimed (i) to ascertain the number of treatment referrals and information about protection orders given to survivors of domestic violence presenting for emergency trauma care, as reported at the one-month visit, (ii) to obtain a profile of violent incidents and injuries, and (iii) to assess self-esteem and posttraumatic and depressive symptomatology in the aftermath of injury. Methods A survey of 62 participants presenting in the acute aftermath of domestic violence (as defined by the Domestic Violence Act of 1998) was conducted over 12 weeks at the Trauma and Resuscitation Unit of a Level One trauma centre in an urban public hospital in South Africa.1 Following informed consent, face-to-face structured interviews were conducted during admission and a month later. The following instruments were administered at baseline: a Demographic and Injury Questionnaire, the Beck Depression and Rosenberg Self-Esteem Inventories, and the Davidson Trauma Scale. A psychosocial questionnaire was administered at the one-month follow-up. Results Fifty-eight per cent of the participants were female and 42% were male. Seventy-four per cent of the perpetrators were male. Ninety-five per cent of the participants said that no health professional had informed them about where or how they could find help. Although all were seriously injured, 76% of the participants said only the researcher had asked about their experience. Sixty-six per cent of the cases of domestic violence were related to intimate partner violence. Overall, subjects displayed high levels of depressive and post-traumatic stress symptomatology that had neither been treated nor adequately referred. Conclusion Even though domestic violence poses significant health threats and costs to the health system, it appears to be a neglected area of South African health care. Health professionals should at least be able to identify and intervene within the "open window" period when psychosocial opportunities are pivotal. South African Family Practice Vol. 49 (3) 2007: pp. 1

Evolution of communication signals and information during species radiation

Communicating species identity is a key component of many animal signals. However, whether selection for species recognition systematically increases signal diversity during clade radiation remains debated. Here we show that in woodpecker drumming, a rhythmic signal used during mating and territorial defense, the amount of species identity information encoded remained stable during woodpeckers’ radiation. Acoustic analyses and evolutionary reconstructions show interchange among six main drumming types despite strong phylogenetic contingencies, suggesting evolutionary tinkering of drumming structure within a constrained acoustic space. Playback experiments and quantification of species discriminability demonstrate sufficient signal differentiation to support species recognition in local communities. Finally, we only find character displacement in the rare cases where sympatric species are also closely related. Overall, our results illustrate how historical contingencies and ecological interactions can promote conservatism in signals during a clade radiation without impairing the effectiveness of information transfer relevant to inter-specific discrimination

Nonlocal Conductivity in the Vortex-Liquid Regime of a Two-Dimensional Superconductor

We have simulated the time-dependent Ginzburg-Landau equation with thermal fluctuations, to study the nonlocal dc conductivity of a superconducting film. Having examined points in the phase diagram at a wide range of temperatures and fields below the mean-field upper critical field, we find a portion of the vortex-liquid regime in which the nonlocal ohmic conductivity in real space is negative over a distance several times the spacing between vortices. The effect is suppressed when driven beyond linear response. Earlier work had predicted the existence of such a regime, due to the high viscosity of a strongly-correlated vortex liquid. This behavior is clearly distinguishable from the monotonic spatial fall-off of the conductivity in the higher temperature or field regimes approaching the normal state. The possibilities for experimental study of the nonlocal transport properties are discussed.Comment: 18 pages, revtex, 6 postscript figure

Integral sliding mode for the torque-vectoring control of fully electric vehicles: Theoretical design and experimental assessment

This paper presents an integral sliding mode (ISM) formulation for the torque-vectoring (TV) control of a fully electric vehicle. The performance of the controller is evaluated in steady-state and transient conditions, including the analysis of the controller performance degradation due to its real-world implementation. This potential issue, which is typical of sliding mode formulations, relates to the actuation delays caused by the drivetrain hardware configuration, signal discretization, and vehicle communication buses, which can provoke chattering and irregular control action. The controller is experimentally assessed on a prototype electric vehicle demonstrator under the worst-case conditions in terms of drivetrain layout and communication delays. The results show a significant enhancement of the controlled vehicle performance during all maneuvers

Are dieting and dietary inadequacy a second hit in the association with polycystic ovary syndrome severity?

Background The composition of the diet is of increasing importance for the development and maturation of the ovarian follicles. In Polycystic Ovary Syndrome (PCOS) healthy dietary interventions improve the clinical spectrum. We hypothesized that dieting and diet inadequacy in the reproductive life course is associated with impaired programming of ovarian follicles and contributes to the severity of the PCOS phenotype. Methods and Findings To determine associations between the use of a self-initiated diet and diet inadequacy and the severity of the PCOS phenotype, we performed an explorative nested case control study embedded in a periconception cohort of 1,251 patients visiting the preconception outpatient clinic. 218 patients with PCOS and 799 subfertile controls were selected from the cohort and self-administered questionnaires, anthropometric measurements and blood samples were obtained. The Preconception Dietary Risk Score (PDR score), based on the Dutch dietary guidelines, was used to determine diet inadequacy in all women. The PDR score was negatively associated to cobalamin, serum and red blood cell folate and positively to tHcy. PCOS patients (19.9%), in particular the hyperandrogenic (HA) phenotype (22.5%) reported more often the use of a self-initiated diet than controls (13.1%; p = 0.023). The use of an inadequate diet was also significantly higher in PCOS than in controls (PDR score 3.7 vs 3.5; p = 0.017) and every point increase was associated with a more than 1.3 fold higher risk of the HA phenotype (adjusted OR 1.351, 95% CI 1.09-1.68). Diet inadequacy was independently associated with the anti-Müllerian Hormone (AMH) concentration (β 0.084; p = 0.044; 95% CI 0.002 to 0.165) and free androgen index (β 0.128; p = 0.013; 95% CI 0.028 to 0.229) in PCOS patients. Conclusions The use of a self-initiated diet and diet inadequacy is associated with PCOS, in particular with the severe HA phenotype. This novel finding substantiated by the association between diet inadequacy and AMH needs further investigation

Adaptive Filtering Enhances Information Transmission in Visual Cortex

Sensory neuroscience seeks to understand how the brain encodes natural environments. However, neural coding has largely been studied using simplified stimuli. In order to assess whether the brain's coding strategy depend on the stimulus ensemble, we apply a new information-theoretic method that allows unbiased calculation of neural filters (receptive fields) from responses to natural scenes or other complex signals with strong multipoint correlations. In the cat primary visual cortex we compare responses to natural inputs with those to noise inputs matched for luminance and contrast. We find that neural filters adaptively change with the input ensemble so as to increase the information carried by the neural response about the filtered stimulus. Adaptation affects the spatial frequency composition of the filter, enhancing sensitivity to under-represented frequencies in agreement with optimal encoding arguments. Adaptation occurs over 40 s to many minutes, longer than most previously reported forms of adaptation.Comment: 20 pages, 11 figures, includes supplementary informatio

Entropy and information in neural spike trains: Progress on the sampling problem

The major problem in information theoretic analysis of neural responses and other biological data is the reliable estimation of entropy--like quantities from small samples. We apply a recently introduced Bayesian entropy estimator to synthetic data inspired by experiments, and to real experimental spike trains. The estimator performs admirably even very deep in the undersampled regime, where other techniques fail. This opens new possibilities for the information theoretic analysis of experiments, and may be of general interest as an example of learning from limited data.Comment: 7 pages, 4 figures; referee suggested changes, accepted versio