Baseline and triangulation geometry in a standard plenoptic camera

In this paper, we demonstrate light field triangulation to determine depth distances and baselines in a plenoptic camera. The advancement of micro lenses and image sensors enabled plenoptic cameras to capture a scene from different viewpoints with sufficient spatial resolution. While object distances can be inferred from disparities in a stereo viewpoint pair using triangulation, this concept remains ambiguous when applied in case of plenoptic cameras. We present a geometrical light field model allowing the triangulation to be applied to a plenoptic camera in order to predict object distances or to specify baselines as desired. It is shown that distance estimates from our novel method match those of real objects placed in front of the camera. Additional benchmark tests with an optical design software further validate the model’s accuracy with deviations of less than 0:33 % for several main lens types and focus settings. A variety of applications in the automotive and robotics field can benefit from this estimation model

Challenges of assessing community mortality due to respiratory viruses in children aged less than 5 years

Background: Estimating the real impact of respiratory syncytial virus (RSV) disease is key for the development of vaccines and treatments. Ascertaining the burden of community mortality due to RSV is challenging due to the lack of primary data. Therefore, conducting observational studies to determine the factors associated with community mortality due to the virus in developing countries is important.Objective: Our aim in this study was to describe the obstacles, gaps, and challenges that investigators face in low-income, vulnerable regions in 4 developing countries on 3 continents.Results: The main obstacles and challenges of ascertaining community mortality due to RSV were defining strategies to consent families for testing before burial, sampling individuals at the household level, supporting bereaved parents with different cultural and religious backgrounds, establishing tailored strategies for studies in challenging settings, and integrating RSV mortality data from nasopharyngeal samples.Conclusion: Detailed logistical planning based on population sociodemographic information, grief counseling, staff training, and a multidisciplinary approach with adequate laboratory infrastructure is critical to successful observational community-based RSV studies

Monotonicity of Fitness Landscapes and Mutation Rate Control

A common view in evolutionary biology is that mutation rates are minimised. However, studies in combinatorial optimisation and search have shown a clear advantage of using variable mutation rates as a control parameter to optimise the performance of evolutionary algorithms. Much biological theory in this area is based on Ronald Fisher's work, who used Euclidean geometry to study the relation between mutation size and expected fitness of the offspring in infinite phenotypic spaces. Here we reconsider this theory based on the alternative geometry of discrete and finite spaces of DNA sequences. First, we consider the geometric case of fitness being isomorphic to distance from an optimum, and show how problems of optimal mutation rate control can be solved exactly or approximately depending on additional constraints of the problem. Then we consider the general case of fitness communicating only partial information about the distance. We define weak monotonicity of fitness landscapes and prove that this property holds in all landscapes that are continuous and open at the optimum. This theoretical result motivates our hypothesis that optimal mutation rate functions in such landscapes will increase when fitness decreases in some neighbourhood of an optimum, resembling the control functions derived in the geometric case. We test this hypothesis experimentally by analysing approximately optimal mutation rate control functions in 115 complete landscapes of binding scores between DNA sequences and transcription factors. Our findings support the hypothesis and find that the increase of mutation rate is more rapid in landscapes that are less monotonic (more rugged). We discuss the relevance of these findings to living organisms

EQUIP: Implementing chronic care principles and applying formative evaluation methods to improve care for schizophrenia: QUERI Series

<p>Abstract</p> <p>Background</p> <p>This paper presents a case study that demonstrates the evolution of a project entitled "Enhancing QUality-of-care In Psychosis" (EQUIP) that began approximately when the U.S. Department of Veterans Affairs' Quality Enhancement Research Initiative (QUERI), and implementation science were emerging. EQUIP developed methods and tools to implement chronic illness care principles in the treatment of schizophrenia, and evaluated this implementation using a small-scale controlled trial. The next iteration of the project, EQUIP-2, was further informed by implementation science and the use of QUERI tools.</p> <p>Methods</p> <p>This paper reports the background, development, results and implications of EQUIP, and also describes ongoing work in the second phase of the project (EQUIP-2). The EQUIP intervention uses implementation strategies and tools to increase the adoption and implementation of chronic illness care principles. In EQUIP-2, these strategies and tools are conceptually grounded in a stages-of-change model, and include clinical and delivery system interventions and adoption/implementation tools. Formative evaluation occurs in conjunction with the intervention, and includes developmental, progress-focused, implementation-focused, and interpretive evaluation.</p> <p>Results</p> <p>Evaluation of EQUIP provided an understanding of quality gaps <it>and </it>how to address related problems in schizophrenia. EQUIP showed that solutions to quality problems in schizophrenia differ by treatment domain and are exacerbated by a lack of awareness of evidence-based practices. EQUIP also showed that improving care requires creating resources for physicians to help them easily implement practice changes, plus intensive education as well as product champions who help physicians use these resources. Organizational changes, such as the addition of care managers and informatics systems, were shown to help physicians with identifying problems, making referrals, and monitoring follow-up. In EQUIP-2, which is currently in progress, these initial findings were used to develop a more comprehensive approach to implementing and evaluating the chronic illness care model.</p> <p>Discussion</p> <p>In QUERI, small-scale projects contribute to the development and enhancement of hands-on, action-oriented service-directed projects that are grounded in current implementation science. This project supports the concept that QUERI tools can be useful in implementing complex care models oriented toward evidence-based improvement of clinical care.</p

Optimization and clinical validation of a pathogen detection microarray

New design and optimization of pathogen detection microarrays is shown to allow robust and accurate detection of a range of pathogens. The customized microarray platform includes a method for reducing PCR bias during DNA amplification

Effect of directness of exposure and trauma type on Mental Health Literacy of PTSD

Background: Research has demonstrated that Post-Traumatic Stress Disorder (PTSD) is one of the most widely recognized mental disorders, but recognition is affected by trauma type. Aims: The current study investigated the effect of direct versus indirect exposure to traumatic event and trauma types on Mental Health Literacy (MHL) of PTSD. Methods: Two hundred and thirty-three participants were asked to identify the mental health problem after presentation of an unlabeled vignette describing a character experiencing PTSD symptoms. The six vignettes described the same symptoms but differed in directness (direct/indirect exposure) and trauma type (rape, military combat or man-made disaster). It was hypothesized that (1) recognition rate would be higher in direct than indirect conditions, and (2) higher in military combat, followed by man-made disaster, and lowest in rape condition. Results: Overall, correct recognition of PTSD was 42.5%. Recognition in direct exposure vignettes was significantly higher than indirect, supporting the first hypothesis. The second hypothesis was only partly supported. While PTSD recognition in rape vignettes was significantly lower than the other two scenarios, no difference was found between combat and man-made disaster trauma types. Conclusions: Our findings implied under-recognition of PTSD, with lack of awareness of different causes of PTSD and of PTSD from indirect trauma exposure. The latter finding is important in the light of DSM-V revisions to diagnostic criteria for PTSD.</p

Studying Cat (Felis catus) Diabetes: Beware of the Acromegalic Imposter

Naturally occurring diabetes mellitus (DM) is common in domestic cats (Felis catus). It has been proposed as a model for human Type 2 DM given many shared features. Small case studies demonstrate feline DM also occurs as a result of insulin resistance due to a somatotrophinoma. The current study estimates the prevalence of hypersomatotropism or acromegaly in the largest cohort of diabetic cats to date, evaluates clinical presentation and ease of recognition. Diabetic cats were screened for hypersomatotropism using serum total insulin-like growth factor-1 (IGF-1; radioimmunoassay), followed by further evaluation of a subset of cases with suggestive IGF-1 (>1000 ng/ml) through pituitary imaging and/ or histopathology. Clinicians indicated pre-test suspicion for hypersomatotropism. In total 1221 diabetic cats were screened; 319 (26.1%) demonstrated a serum IGF-1>1000 ng/ml (95% confidence interval: 23.6-28.6%). Of these cats a subset of 63 (20%) underwent pituitary imaging and 56/63 (89%) had a pituitary tumour on computed tomography; an additional three on magnetic resonance imaging and one on necropsy. These data suggest a positive predictive value of serum IGF-1 for hypersomatotropism of 95% (95% confidence interval: 90-100%), thus suggesting the overall hypersomatotropism prevalence among UK diabetic cats to be 24.8% (95% confidence interval: 21.2-28.6%). Only 24% of clinicians indicated a strong pre-test suspicion; most hypersomatotropism cats did not display typical phenotypical acromegaly signs. The current data suggest hypersomatotropism screening should be considered when studying diabetic cats and opportunities exist for comparative acromegaly research, especially in light of the many detected communalities with the human disease

30 days wild: development and evaluation of a large-scale nature engagement campaign to improve well-being

There is a need to increase people’s engagement with and connection to nature, both for human well-being and the conservation of nature itself. In order to suggest ways for people to engage with nature and create a wider social context to normalise nature engagement, The Wildlife Trusts developed a mass engagement campaign, 30 Days Wild. The campaign asked people to engage with nature every day for a month. 12,400 people signed up for 30 Days Wild via an online sign-up with an estimated 18,500 taking part overall, resulting in an estimated 300,000 engagements with nature by participants. Samples of those taking part were found to have sustained increases in happiness, health, connection to nature and pro-nature behaviours. With the improvement in health being predicted by the improvement in happiness, this relationship was mediated by the change in connection to nature

A clinical pathway for community-acquired pneumonia: an observational cohort study

<p>Abstract</p> <p>Background</p> <p>Six hospitals instituted a voluntary, system-wide, pathway for community acquired pneumonia (CAP). We proposed this study to determine the impact of pathway antibiotics on patient survival, hospital length of stay (LOS), and total hospital cost.</p> <p>Methods</p> <p>Data were collected for adults from six U.S. hospitals with a principal CAP discharge diagnosis code, a chest infiltrate, and medical notes indicative of CAP from 2005-2007. Pathway and non-pathway cohorts were assigned according to antibiotics received within 48 hours of admission. Pathway antibiotics included levofloxacin 750 mg monotherapy or ceftriaxone 1000 mg plus azithromycin 500 mg daily. Multivariable regression models assessed 90-day mortality, hospital LOS, total hospital cost, and total pharmacy cost.</p> <p>Results</p> <p>Overall, 792 patients met study criteria. Of these, 505 (64%) received pathway antibiotics and 287 (36%) received non-pathway antibiotics. Adjusted means and p-values were derived from Least Squares regression models that included Pneumonia Severity Index risk class, patient age, heart failure, chronic obstructive pulmonary disease, and admitting hospital as covariates. After adjustment, patients who received pathway antibiotics experienced lower adjusted 90-day mortality (<it>p </it>= 0.02), shorter mean hospital LOS (3.9 vs. 5.0 days, <it>p </it>< 0.01), lower mean hospital costs ($2,485 vs.$3,281, <it>p </it>= 0.02), and similar mean pharmacy costs ($356 vs.$442, <it>p </it>= 0.11).</p> <p>Conclusions</p> <p>Pathway antibiotics were associated with improved patient survival, hospital LOS, and total hospital cost for patients admitted to the hospital with CAP.</p

Multiple micronutrient supplementation improves vitamin B12 and folate concentrations of HIV infected children in Uganda: a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>The effect of multiple micronutrient supplementation on vitamin B₁₂and folate has hither to not been reported in African HIV infected children. This paper describes vitamin B₁₂and folate status of Ugandan HIV infected children aged 1-5 years and reports the effect of multiple micronutrient supplementation on serum vitamin B₁₂and folate concentrations.</p> <p>Methods</p> <p>Of 847 children who participated in a multiple micronutrient supplementation trial, 214 were assessed for vitamin B₁₂and folate concentrations pre and post supplementation. One hundred and four children were randomised to two times the recommended dietary allowance (RDA) of a 14 multiple micronutrient supplement (MMS) and 114 to a 'standard of care' supplement of 6 multivitamins (MV). Serum vitamin B₁₂was measured by an electrochemiluminescence immunoassay and folate by a competitive protein-binding assay using Modular E (Roche) automatic analyzer. Vitamin B₁₂concentrations were considered low if less than 221picomoles per litre (pmol/L) and folate if < 13.4 nanomoles per litre (nmol/L). The Wilcoxon Signed Ranks test was used to measure the difference between pre and post supplementation concentrations.</p> <p>Results</p> <p>Vitamin B₁₂was low in 60/214 (28%) and folate in 62/214 (29.0%) children. In the MMS group, the median concentration (IQR) of vitamin B₁₂at 6 months was 401.5 (264.3 - 518.8) pmol/L compared to the baseline of 285.5 (216.5 - 371.8) pmol/L, p < 0.001. The median (IQR) folate concentrations increased from 17.3 (13.5 - 26.6) nmol/L to 27.7 (21.1 - 33.4) nmol/L, p < 0.001. In the 'standard of care' MV supplemented group, the median concentration (IQR) of vitamin B₁₂at 6 months was 288.5 (198.8 - 391.0) pmol/L compared to the baseline of 280.0 (211.5 - 386.3) pmol/L while the median (IQR) folate concentrations at 6 months were 16.5 (11.7 - 22.1) nmol/L compared to 15.7 (11.9 - 22.1) nmol/L at baseline. There was a significant difference in the MMS group in both vitamin B₁₂and folate concentrations but no difference in the MV group.</p> <p>Conclusions</p> <p>Almost a third of the HIV infected Ugandan children aged 1-5 years had low serum concentrations of vitamin B₁₂and folate. Multiple micronutrient supplementation compared to the 'standard of care' supplement of 6 multivitamins improved the vitamin B₁₂and folate status of HIV infected children in Uganda.</p> <p>Trial registration</p> <p><url>http://ClinicalTrials.gov</url><a href="http://www.clinicaltrials.gov/ct2/show/NCT00122941">NCT00122941</a>)</p