Multiple range imaging camera operation with minimal performance impact

Time-of-flight range imaging cameras operate by illuminating a scene with amplitude modulated light and measuring the phase shift of the modulation envelope between the emitted and reflected light. Object distance can then be calculated from this phase measurement. This approach does not work in multiple camera environments as the measured phase is corrupted by the illumination from other cameras. To minimize inaccuracies in multiple camera environments, replacing the traditional cyclic modulation with pseudo-noise amplitude modulation has been previously demonstrated. However, this technique effectively reduced the modulation frequency, therefore decreasing the distance measurement precision (which has a proportional relationship with the modulation frequency). A new modulation scheme using maximum length pseudo-random sequences binary phase encoded onto the existing cyclic amplitude modulation, is presented. The effective modulation frequency therefore remains unchanged, providing range measurements with high precision. The effectiveness of the new modulation scheme was verified using a custom time-of-flight camera based on the PMD19-K2 range imaging sensor. The new pseudo-noise modulation has no significant performance decrease in a single camera environment. In a two camera environment, the precision is only reduced by the increased photon shot noise from the second illumination source

Smartphone-based Wireless Operated Milliliter-scale Bioreactor

This paper presents the development of a smartphone-based wireless operated milliliter scale bioreactor. The bioreactor has a working volume of 18 mL and is made of poly (methylmethacrylate) (PMMA) and poly (dimethylsiloxane) (PDMS) polymers using a laser engraving methodology. Temperature and reactor stirring speed are the controlled variables and wireless communication is achieved through a wireless transceiver embedded in a low-cost controller platform. The results attained are very promising as the controller is able to control the desired reactor variables precisely through wireless communications

Continuous ASL perfusion fMRI investigation of higher cognition: Quantification of tonic CBF changes during sustained attention and working memory tasks

Arterial spin labeling (ASL) perfusion fMRI is an emerging method in clinical neuroimaging. Its non-invasiveness, absence of low frequency noise, and ability to quantify the absolute level of cerebral blood flow (CBF) make the method ideal for longitudinal designs or low frequency paradigms. Despite the usefulness in the study of cognitive dysfunctions in clinical populations, perfusion activation studies to date have been conducted for simple sensorimotor paradigms or with single-slice acquisition, mainly due to technical challenges. Using our recently developed amplitude-modulated continuous ASL (CASL) perfusion fMRI protocol, we assessed the feasibility of a higher level cognitive activation study in twelve healthy subjects. Taking advantage of the ASL noise properties, we were able to study tonic CBF changes during uninterrupted 6-min continuous performance of working memory and sustained attention tasks. For the visual sustained attention task, regional CBF increases (6–12 ml/100 g/min) were detected in the right middle frontal gyrus, the bilateral occipital gyri, and the anterior cingulate/medial frontal gyri. During the 2-back working memory task, significantly increased activations (7–11 ml/100 g/min) were found in the left inferior frontal/precentral gyri, the left inferior parietal lobule, the anterior cingulate/medial frontal gyri, and the left occipital gyrus. Locations of activated and deactivated areas largely concur with previous PET and BOLD fMRI studies utilizing similar paradigms. These results demonstrate that CASL perfusion fMRI can be successfully utilized for the investigation of the tonic CBF changes associated with high level cognitive operations. Increased applications of the method to the investigation of cognitively impaired populations are expected to follow

3D Printing of Food for People with Swallowing Difficulties

Dysphagia affects many people worldwide. Modifying foods to standard consistencies, and manual design and assembly of foods for the daily requirements of people with dysphagia is challenging. People with dysphagia may develop a dislike for pureed foods due to the unattractiveness of the appearance of the foods, the lack of variety in daily meals, and the diluted taste of meals. Three-dimensional (3D) food printing is emerging as a method for making foods for people with special mealtime needs. Very few efforts have been made to apply 3D food printing to improving the lives of people with special mealtime needs such as those with dysphagia. This paper presents the design and 3D printing of visually appetizing pureed foods for people with dysphagia with high consistency and repeatability. A tuna fish involving pureed tuna (protein), pureed pumpkin (fruit), and pureed beetroot (vegetable) is designed and then 3D printed. The steps involved in the design of tuna fish, preparation of purees, and printing of tuna fish are described. The obtained results are presented, and the findings of this research work are discussed

Design of a deep learning surrogate model for the prediction of FHR design parameters

All rights reserved. Following previous work by Xing and Shwageraus, a large corpus of data has been collected for simulated AGR-style fuel assembly design in FHRs. The results exhibit a nonlinear system response, so a ‘deep’ multi-layer perceptron surrogate model is designed and tested for prediction of design parameters. This neuro-surrogate regression model could be useful for the fast optimization of the design parameters, for example in multiobjective optimization problems, due to the extremely fast evaluation time. Source code is made available for the audit and authentication of the scientific method

Initial results of tests of depth markers as a surface diagnostic for fusion devices

The Accelerator-Based In Situ Materials Surveillance (AIMS) diagnostic was developed to perform in situ ion beam analysis (IBA) on Alcator C-Mod in August 2012 to study divertor surfaces between shots. These results were limited to studying low-Z surface properties, because the Coulomb barrier precludes nuclear reactions between high-Z elements and the ∼1 MeV AIMS deuteron beam. In order to measure the high-Z erosion, a technique using deuteron-induced gamma emission and a low-Z depth marker is being developed. To determine the depth of the marker while eliminating some uncertainty due to beam and detector parameters, the energy dependence of the ratio of two gamma yields produced from the same depth marker will be used to determine the ion beam energy loss in the surface, and thus the thickness of the high-Z surface. This paper presents the results of initial trials of using an implanted depth marker layer with a deuteron beam and the method of ratios. First tests of a lithium depth marker proved unsuccessful due to the production of conflicting gamma peaks, among other issues. However, successful trials with a boron depth marker show that it is possible to measure the depth of the marker layer with the method of gamma yield ratios.United States. Department of Energy. (grant number DE-FG02-94ER54235, cooperative agreement number DEFC02-99ER54512

The 'causes' of teenage pregnancy: review of South African research - Part 2

This article forms the second of a two-part series in which South African research on teenage pregnancy is reviewed. Part 1 of the series dealt with the consequences of teenage pregnancy; this paper reviews the 'causes' thereof. International literature is incorporated in the discussion by way of comparison. Contributory factors which have been investigated by South African researchers include: reproductive ignorance; the earlier occurrence of menarche; risktaking behaviour; psychological problems; peer influence; co-ercive sexual relations; dysfunctional family patterns; poor health services; socio-economic status; the breakdown of cultural traditions; and the cultural value placed on children. Preston-Whyte and colleagues present a revisionist argument, stating that early pregnancy may represent a rational life choice for certain adolescent women. The article is concluded with comments on methodological problems encountered in the South African research, and a discussion on the implications in terms of policy formulation

Application of the speed-duration relationship to normalize the intensity of high-intensity interval training

The tolerable duration of continuous high-intensity exercise is determined by the hyperbolic Speed-tolerable duration (S-tLIM) relationship. However, application of the S-tLIM relationship to normalize the intensity of High-Intensity Interval Training (HIIT) has yet to be considered, with this the aim of present study. Subjects completed a ramp-incremental test, and series of 4 constant-speed tests to determine the S-tLIM relationship. A sub-group of subjects (n = 8) then repeated 4 min bouts of exercise at the speeds predicted to induce intolerance at 4 min (WR4), 6 min (WR6) and 8 min (WR8), interspersed with bouts of 4 min recovery, to the point of exercise intolerance (fixed WR HIIT) on different days, with the aim of establishing the work rate that could be sustained for 960 s (i.e. 4×4 min). A sub-group of subjects (n = 6) also completed 4 bouts of exercise interspersed with 4 min recovery, with each bout continued to the point of exercise intolerance (maximal HIIT) to determine the appropriate protocol for maximizing the amount of high-intensity work that can be completed during 4×4 min HIIT. For fixed WR HIIT tLIM of HIIT sessions was 399±81 s for WR4, 892±181 s for WR6 and 1517±346 s for WR8, with total exercise durations all significantly different from each other (P<0.050). For maximal HIIT, there was no difference in tLIM of each of the 4 bouts (Bout 1: 229±27 s; Bout 2: 262±37 s; Bout 3: 235±49 s; Bout 4: 235±53 s; P>0.050). However, there was significantly less high-intensity work completed during bouts 2 (153.5±40. 9 m), 3 (136.9±38.9 m), and 4 (136.7±39.3 m), compared with bout 1 (264.9±58.7 m; P>0.050). These data establish that WR6 provides the appropriate work rate to normalize the intensity of HIIT between subjects. Maximal HIIT provides a protocol which allows the relative contribution of the work rate profile to physiological adaptations to be considered during alternative intensity-matched HIIT protocols

Evaluating a computer aid for assessing stomach symptoms (ECASS): study protocol for a randomised controlled trial

Background: For most cancers, only a minority of patients have symptoms meeting the National Institute for Health and Clinical Excellence guidance for urgent referral. For gastro-oesophageal cancers, the ‘alarm’ symptoms of dysphagia and weight loss are reported by only 32 and 8 % of patients, respectively, and their presence correlates with advanced-stage disease. Electronic clinical decision-support tools that integrate with clinical computer systems have been developed for general practice, although uncertainty remains concerning their effectiveness. The objectives of this trial are to optimise the intervention and establish the acceptability of both the intervention and randomisation, confirm the suitability and selection of outcome measures, finalise the design for the phase III definitive trial, and obtain preliminary estimates of the intervention effect. Methods/design: This is a two-arm, multi-centre, cluster-randomised, controlled phase II trial design, which will extend over a 16-month period, across 60 general practices within the North East and North Cumbria and the Eastern Local Clinical Research Network areas. Practices will be randomised to receive either the intervention (the electronic clinical decision-support tool) or to act as a control (usual care). From these practices, we will recruit 3000 adults who meet the trial eligibility criteria and present to their GP with symptoms suggestive of gastro-oesophageal cancer. The main measures are the process data, which include the practitioner outcomes, service outcomes, diagnostic intervals, health economic outcomes, and patient outcomes. One-on-one interviews in a sub-sample of 30 patient-GP dyads will be undertaken to understand the impact of the use or non-use of the electronic clinical decision-support tool in the consultation. A further 10–15 GPs will be interviewed to identify and gain an understanding of the facilitators and constraints influencing implementation of the electronic clinical decision-support tool in practice. Discussion: We aim to generate new knowledge on the process measures regarding the use of electronic clinical decision-support tools in primary care in general and to inform a subsequent definitive phase III trial. Preliminary data on the impact of the support tool on resource utilisation and health care costs will also be collected. Trial registration: ISRCTN Registry, ISRCTN12595588

The role of children in their HIV-positive parents’ management of antiretroviral therapy in Uganda

Adjustment to life on antiretroviral therapy (ART) and living with HIV as a long-term chronic condition, pose significant medical, social and economic challenges. We investigated children’s role in supporting HIV-positive parents to self-manage life on ART. Between 2010 and 2012, we conducted a qualitative study using semi-structured interviews with 38 HIV-positive parents who had been on ART for over a year. They were randomly selected from people accessing ART from three delivery sites in Wakiso district, Uganda. Data were analysed thematically. Participants reported children between the ages of 1 and 47 years providing support. Children were a source of happiness, self-worth, encouragement, and comfort. Both younger and older children supported parents’ adherence to treatment through reminding them to take the drugs and honour clinic appointments. Older children provided money to buy medication, food and shelter. Parents reported that the encouragement they received after they disclosed to their children enhanced their survival. After HIV disclosure to their children many of their fears about the future were allayed. Thinking about their children’s future brought hope. However, looking after younger children while on ART could be burdensome since some parents could not work to their full capacity due to reduced physical health. Children are an important resource in their parents’ adjustment to living with HIV while taking ART. There is a need for children to be supported by appropriate policy and other social and health development structures