A Navigation System for the Visually Impaired: A Fusion of Vision and Depth Sensor

For a number of years, scientists have been trying to develop aids that can make visually impaired people more independent and aware of their surroundings. Computer-based automatic navigation tools are one example of this, motivated by the increasing miniaturization of electronics and the improvement in processing power and sensing capabilities. This paper presents a complete navigation system based on low cost and physically unobtrusive sensors such as a camera and an infrared sensor. The system is based around corners and depth values from Kinect’s infrared sensor. Obstacles are found in images from a camera using corner detection, while input from the depth sensor provides the corresponding distance. The combination is both efficient and robust. The system not only identifies hurdles but also suggests a safe path (if available) to the left or right side and tells the user to stop, move left, or move right. The system has been tested in real time by both blindfolded and blind people at different indoor and outdoor locations, demonstrating that it operates adequately.</jats:p

Biogenic propane production by a marine Photobacterium strain isolated from the Western English Channel

Propane is a major component of liquefied petroleum gas, a major energy source for off-grid communities and industry. The replacement of fossil fuel-derived propane with more sustainably derived propane is of industrial interest. One potential production route is through microbial fermentation. Here we report, for the first time, the isolation of a marine bacterium from sediment capable of natural propane biosynthesis. Propane production, both in mixed microbial cultures generated from marine sediment and in bacterial monocultures was detected and quantified by gas chromatography–flame ionization detection. Using DNA sequencing of multiple reference genes, the bacterium was shown to belong to the genus Photobacterium. We postulate that propane biosynthesis is achieved through inorganic carbonate assimilation systems. The discovery of this strain may facilitate synthetic biology routes for industrial scale production of propane via microbial fermentation

Developmental changes in spinal neuronal properties, motor network configuration, and neuromodulation at free-swimming stages of Xenopus tadpoles

We describe a novel preparation of the isolated brainstem and spinal cord from pro-metamorphic tadpole stages of the South African clawed frog (Xenopus laevis) that permits whole cell patch-clamp recordings from neurons in the ventral spinal cord. Previous research on earlier stages of the same species has provided one of the most detailed understandings of the design and operation of a CPG circuit. Here we have addressed how development sculpts complexity from this more basic circuit. The preparation generates bouts of fictive31 swimming activity either spontaneously or in response to electrical stimulation of the optic tectum, allowing an investigation into how the neuronal properties, activity patterns and neuromodulation of locomotor rhythm generation change during development. We describe an increased repertoire of cellular responses compared to younger larval stages and investigate the cellular level effects of nitrergic neuromodulation as well as the development of a sodium pump-mediated ultra-slow afterhyperpolarisation (usAHP) in these free-swimming larval animals.PostprintPeer reviewe

Deep-brain photoreception links luminance detection to motor output in Xenopus frog tadpoles

SPC was supported by a BBSRC studentship.Nonvisual photoreceptors are widely distributed in the retina and brain, but their roles in animal behavior remain poorly understood. Here we document a previously unidentified form of deep-brain photoreception in Xenopus laevis frog tadpoles. The isolated nervous system retains sensitivity to light even when devoid of input from classical eye and pineal photoreceptors. These preparations produce regular bouts of rhythmic swimming activity in ambient light but fall silent in the dark. This sensitivity is tuned to short-wavelength UV light; illumination at 400 nm initiates motor activity over a broad range of intensities, whereas longer wavelengths do not cause a response. The photosensitive tissue is located in a small region of caudal diencephalon—this region is necessary to retain responses to illumination, whereas its focal illumination is sufficient to drive them. We present evidence for photoreception via the light-sensitive proteins opsin (OPN)5 and/or cryptochrome 1, because populations of OPN5-positive and cryptochrome-positive cells reside within the caudal diencephalon. This discovery represents a hitherto undescribed vertebrate pathway that links luminance detection to motor output. The pathway provides a simple mechanism for light avoidance and/or may reinforce classical circadian systems.PostprintPeer reviewe

Oxidative dehydrogenation of 1-butene to 1,3-butadiene over metal ferrite catalysts

The oxidative dehydrogenation (ODH) of 1-butene to 1,3-butadiene was studied over a series of AFe2O4 catalysts, where A = Zn, Mn, Ni, Cu, Mg and Fe. The catalysts were characterised by XPS, EPR spectroscopy, BET surface area analysis, Raman spectroscopy and XRD. All the ferrites were active for ODH and gave an order of activity after 80 h on-stream of ZnFe2O4 &gt; NiFe2O4 &gt; MnFe2O4 &gt; MgFe2O4 &gt; CuFe2O4 &gt; FeFe2O4. All catalysts lost significant surface area (up to ~ 80%) under reaction conditions of 0.75:1:15 oxygen:1-butene:steam with an overall GHSV of 10,050 h−1 at 693 K. Fe3O4 was unstable under reaction conditions and was converted to Fe2O3, which showed very low activity. Nickel ferrite was the only material that gave carbon dioxide as a significant product, all others were selective to 1,3-butadiene. Zinc ferrite gave a steady-state yield of 1,3-butadiene of ~ 80%. Inversion parameters were determined for the ferrites from XPS and a correlation was obtained between 1,3-butadiene yield and inversion parameter, indicating that Fe3+ in an octahedral hole is a key species in the mechanism of oxidative dehydrogenation. Butene isomerisation and ODH were shown to occur on different sites

Recommendations for determining HPV status in patients with oropharyngeal cancers under TNM8 guidelines : a two-tier approach

ACKNOWLEDGEMENTS The funders had no role in study design, collection, data analysis or interpretation of the data. This work received funding from the Medical Research Council (D.Mc.C. and J.J.), the Health and Social Care Research and Development Division of the Northern Ireland Public Health Agency (D.M.c.C., J.J., M.Mo.), the Wellcome Trust through the Wellcome-FDS Research Training Fellowship, the Faculty of Dental Surgery of the Royal College of Surgeons of England (A.G.S.) and GlaxoSmithKline Ltd (T.J.). The Northern Ireland OPSCC TMAs used in this research were received from the Northern Ireland Biobank which has received funds from Health and Social Care Research and Development Division of the Public Health Agency in Northern Ireland and the Friends of the Cancer Centre. The Northern Ireland Cancer Registry who receives funding from the Northern Ireland Public Health Agency carried out collection of clinical data for the Northern Ireland OPSCC patients. The Faculty of Dental Surgery of the Royal College of Surgeons of England and the Liverpool Bio-innovation Hub Biobank carried out collection of clinical data for the Liverpool OPSCC patients.Peer reviewedPublisher PD

Addition to inhaled corticosteroids of long-acting beta2-agonists versus anti-leukotrienes for chronic asthma

Asthma patients who continue to experience symptoms despite being on regular inhaled corticosteroids (ICS) represent a management challenge. Long-acting beta2-agonists (LABA) or anti-leukotrienes (LTRA) are two treatment options that could be considered as add-on therapy to ICS.ObjectivesWe compared the efficacy and safety profile of adding either daily LABA or LTRA in adults and children with asthma who remain symptomatic on ICS.Search strategyWe searched the Cochrane Airways Group Specialised Register (up to and including March 2010). We consulted reference lists of all included studies and contacted authors and pharmaceutical manufacturers for other published or unpublished studies.Selection criteriaWe included randomised controlled trials (RCTs) conducted in adults or children with recurrent asthma that was treated with ICS and where a fixed dose of a long-acting beta2-agonist or leukotriene agent was added for a minimum of 28 days.Data collection and analysisTwo authors independently assessed the risk of bias of included studies and extracted data. We sought unpublished data and further details of study design, where necessary.Main resultsWe included 17 RCTs (7032 participants), of which 16 recruited adults and adolescents (6850) and one recruited children aged 6 to 17 years (182). Participants demonstrated substantial reversibility to short-acting beta-agonist at baseline. The studies were at a low risk of bias. The risk of exacerbations requiring systemic corticosteroids was lower with the combination of LABA and ICS compared with LTRA and ICS, from 11% to 9% (RR 0.83, 95% CI 0.71 to 0.97; six studies, 5571 adults). The number needed to treat (NNT) with LABA compared to LTRA to prevent one exacerbation over 48 weeks was 38 (95% CI 22 to 244). The choice of LTRA did not significantly affect the results. The effect appeared stronger in the trials using a single device to administer ICS and LABA compared to those using two devices. In the absence of data from the paediatric trial and the clinical homogeneity of studies, we could not perform subgroup analyses. The addition to ICS of LABA compared to LTRA was associated with a statistically greater improvement from baseline in several of the secondary outcomes, including lung function, functional status measures and quality of life. Serious adverse events were more common with LABA than LTRA, although the estimate was imprecise (RR 1.35, 95% CI 1.00 to 1.82), and the NNT to harm for one additional patient to suffer a serious adverse event on LABA over 48 weeks was 78 (95% CI 33 to infinity). The risk of withdrawal for any reason in adults was significantly lower with LABA and ICS compared to LTRA and ICS (RR 0.84, 95% CI 0.74 to 0.96).Authors' conclusionsIn adults with asthma that is inadequately controlled on low doses of inhaled steroids and showing significant reversibility with beta2-agonists, LABA is superior to LTRA in reducing oral steroid treated exacerbations. Differences favouring LABA in lung function, functional status and quality of life scores are generally modest. There is some evidence of increased risk of SAEs with LABA. The findings support the use of a single inhaler for the delivery of LABA and inhaled corticosteroids. We are unable to draw conclusions about which treatment is better as add-on therapy for children.PLAIN LANGUAGE SUMMARYWhat are the effects of long-acting beta2-agonists compared with anti-leukotrienes when added to inhaled steroids?People who continue to experience asthma symptoms despite regularly taking inhaled corticosteroids are a challenge for management. It is not clear whether the addition of a long-acting beta2-agonist (LABA) such as formoterol or salmeterol would provide more benefit in comparison with an oral anti-leukotriene agent (LTRA), for example zafirlukast or montelukast.Seventeen trials (16 in adults and one in children) were included in this review and were of good quality. We found that the addition of a LABA provides significantly greater protection against exacerbations requiring oral steroids when compared with a LTRA for adults. Based on the results of our analyses, approximately 38 adults (with a range of between 22 and 244) would need to be treated with a LABA rather than a LTRA for 48 weeks to prevent one experiencing an exacerbation needing a course of oral steroids. The trial on children did not contribute data on the main outcome and therefore we could not draw any conclusions for children.LABAs also led to a greater improvement in lung function, improvement in symptoms, use of rescue medication, quality of life and symptoms compared to the use of LTRAs. The magnitude of the improvements was modest. Serious adverse events were more frequent with LABA than with LTRAs although this result was imprecise. Based on our analyses, around 78 people would need to be treated for 48 weeks with a LABA rather than a LTRA for one of them to experience a serious adverse event. However, due to the lack of precision around our result, the true number could be between 33 and infinity. There are currently insufficient data to draw any conclusions about the effects of these drugs in children

Antimicrobial resistance in ovine bacteria: a sheep in wolf’s clothing?

Background: To monitor the prevalence of antimicrobial resistance (AMR), methods for interpretation of susceptibility phenotypes of bacteria are needed. Reference limits to declare resistance are generally based on or dominated by data from human bacterial isolates and may not reflect clinical relevance or wild type (WT) populations in livestock or other hosts. Methods: We compared the observed prevalence of AMR using standard and bespoke interpretations based on clinical breakpoints or epidemiological cut-offs (ECOFF) using gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria from sheep as exemplars. Isolates were obtained from a cross-sectional study in three lowland sheep flocks in Scotland, and from a longitudinal study in one flock in Norway. S. aureus (n = 101) was predominantly isolated from milk or mammary glands whilst E. coli (n = 103) was mostly isolated from faecal samples. Disc diffusion testing was used to determine inhibition zone diameters, which were interpreted using either clinical breakpoints or ECOFF, which distinguish the bacterial wild type population from bacteria with acquired or mutational resistance to the compound of interest (non-wild type). Standard ECOFF values were considered as well as sheep-specific values calculated from the data using Normalized Resistance Interpretation (NRI) methodology. Results: The prevalence of AMR as measured based on clinical breakpoints was low, e.g. 4.0% for penicillin resistance in S. aureus. Estimation of AMR prevalence based on standard ECOFFs was hampered by lack of relevant reference values. In addition, standard ECOFFS, which are predominantly based on human data, bisected the normal distribution of inhibition zone diameters for several compounds in our analysis of sheep isolates. This contravenes recommendations for ECOFF setting based on NRI methodology and may lead to high apparent AMR prevalence. Using bespoke ECOFF values based on NRI, S. aureus showed non-wild type for less than 4% of isolates across 13 compounds, and ca. 13% non-wild type for amoxicillin and ampicillin, while E. coli showed non-wild type for less than 3% of isolates across 12 compounds, and ca. 13% non-wild type for tetracyclines and sulfamethoxazole-trimethoprim. Conclusion: The apparent prevalence of AMR in bacteria isolated from sheep is highly dependent on interpretation criteria. The sheep industry may want to establish bespoke cut-off values for AMR monitoring to avoid the use of cut-offs developed for other host species. The latter could lead to high apparent prevalence of resistance, including to critically important antimicrobial classes such as 4th generation cephalosporins and carbapenems, suggesting an AMR problem that may not actually exist

Prevalence and Epidemiology of Non-O157 Escherichia coli Serogroups O26, O103, O111, and O145 and Shiga Toxin Gene Carriage in Scottish Cattle, 2014-2015

International audienceCattle are reservoirs for Shiga toxin Escherichia coli (STEC), bacteria shed in animal feces. Humans are infected through consumption of contaminated food or water and by direct contact, causing serious disease and kidney failure in the most vulnerable