5,528 research outputs found

    The role of Geographic Information Systems and spatial analysis in area-wide vector control programmes

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    Extensive hemicerebral damage after traumatic midterm amniocentesis

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    We present a 28-year-old right-handed male who, at 17 weeks' gestation, suffered a traumatic amniocentesis, and was subsequently born with extensive right-sided cerebral, cerebellar and brainstem damage. The initial amniocentesis was abandoned and repeated 2 weeks later, with normal results, subsequent prenatal ultrasound scans were normal. The patient had an uncomplicated delivery at term, however a complete right sided ptosis and marks on the right parietal region of the scalp were noted. By 4 months of age, a right sided third nerve palsy, a left sided hemiplegia and left visual field defect had been identified, and infantile spasms developed, which were treated successfully with ACTH. No further seizures occurred until habitual seizures began at 7 years of age, consisting of focal seizures with, and without, loss of awareness, with blank spells, abdominal discomfort, head turning, agitation and disorientation. Although initially controlled with antiseizure medication, seizures became refractory within 3 years, occurring several times per day despite extensive medications and vagal nerve stimulation. In recent months, atonic seizures developed, characterised by sudden weakness of the lower limbs causing collapse, not associated with loss of consciousness, with risk of injury and a significant effect on his quality of life. There have not been secondarily generalized tonic-clonic seizures. He achieved undergraduate level education and can walk despite a left hemiparesis

    Influence of visual stimuli on perceptual attributes of spatial audio

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    Reproduced audio is often accompanied with visuals (i.e. television, virtual reality, gaming, and cinema). However, the audio technology for these systems is often researched and evaluated in isolation from the visual component. Previous research indicates that the auditory and visual modalities are not processed separately. For example, visual stimuli can influence ratings of audio quality and vice versa. This paper presents an experiment to investigate the influence of visual stimuli on a set of attributes relevant to the perception of spatial audio. Eighteen participants took part in a paired comparison listening test where they were asked to judge pairs of stimuli rendered to fourteen-, five-, and two-channel systems using ten perceptual attributes. The stimuli were presented in audio only and audio-visual conditions. The results show a significant and large main effect of the loudspeaker configuration for all the tested attributes other than overall spectral balance and depth of field. The effect of visual stimuli was found to be small and significant for the attributes realism, sense of space, and spatial clarity. These results suggest that evaluations of audio-visual technologies aiming to evoke a sense of realism or presence should consider the influence of both the audio and visual modalities

    Elicitation of expert knowledge to inform object-based audio rendering to different systems

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    Object-based audio presents the opportunity to optimise audio reproduction for different listening scenarios. Vector base amplitude panning (VBAP) is typically used to render object-based scenes. Optimizing this process based on knowledge of the perception and practices of experts could result in significant improvements to the end user's listening experience. An experiment was conducted to investigate how content creators perceive changes in the perceptual attributes of the same content rendered to systems with different numbers of channels, and to determine what they would do differently to standard VBAP and matrix based downmixes to minimize these changes. Text mining and clustering of the content creators' responses revealed 6 general mix processes: the spatial spread of individual objects, EQ and processing, reverberation, position, bass, and level. Logistic regression models show the relationships between the mix processes, perceived changes in perceptual attributes, and the rendering method/speaker layout. The relative frequency of use for the different mix processes was found to differ between categories of audio object suggesting that any downmix rules should be object category specific. These results give insight into how object-based audio can be used to improve listener experience and provide the first template for doing this across different reproduction systems

    Analysis of BMAA enantiomers in cycads, cyanobacteria, and mammals: in vivo formation and toxicity of D-BMAA

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    We acknowledge support from the John and Josephine Louis Foundation and the Deerbrook Charitable Trust. PBW acknowledges the use of the EPSRC UK National Mass Spectrometry Facility at Swansea University

    Late-onset bloodstream infection and perturbed maturation of the gastrointestinal microbiota in premature infants

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    Late-onset bloodstream infection (LO-BSI) is a common complication of prematurity, and lack of timely diagnosis and treatment can have life-threatening consequences. We sought to identify clinical characteristics and microbial signatures in the gastrointestinal microbiota preceding diagnosis of LO-BSI in premature infants.Daily faecal samples and clinical data were collected over two years from 369 premature neonates (<32 weeks gestation). We analysed samples from 22 neonates who developed LO-BSI and 44 matched control infants. Next-generation sequencing of 16S rRNA gene regions amplified by PCR from total faecal DNA was used to characterise the microbiota of faecal samples preceding diagnosis from infants with LO-BSI and controls. Culture of selected samples was undertaken, and bacterial isolates identified using MALDI-TOF. Antibiograms from bloodstream and faecal isolates were compared to explore strain similarity.From the week prior to diagnosis, infants with LO-BSI had higher proportions of faecal aerobes/facultative anaerobes compared to controls. Risk factors for LO-BSI were identified by multivariate analysis. Enterobacteriaceal sepsis was associated with antecedent multiple lines, low birth weight and a faecal microbiota with prominent Enterobacteriaceae. Staphylococcal sepsis was associated with Staphylococcus OTU faecal over-abundance, and the number of days prior to diagnosis of mechanical ventilation and of the presence of centrally-placed lines. In 12 cases, the antibiogram of the bloodstream isolate matched that of a component of the faecal microbiota in the sample collected closest to diagnosis.The gastrointestinal tract is an important reservoir for LO-BSI organisms, pathogens translocating across the epithelial barrier. LO-BSI is associated with an aberrant microbiota, with abundant staphylococci and Enterobacteriaceae and a failure to mature towards predominance of obligate anaerobes

    Size and emotion or depth and emotion? Evidence, using Matryoshka (Russian) dolls, of children using physical depth as a proxy for emotional charge

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    Background: The size and emotion effect is the tendency for children to draw people and other objects with a positive emotional charge larger than those with a negative or neutral charge. Here we explored the novel idea that drawing size might be acting as a proxy for depth (proximity).Methods: Forty-two children (aged 3-11 years) chose, from 2 sets of Matryoshka (Russian) dolls, a doll to represent a person with positive, negative or neutral charge, which they placed in front of themselves on a sheet of A3 paper. Results: We found that the children used proximity and doll size, to indicate emotional charge. Conclusions: These findings are consistent with the notion that in drawings, children are using size as a proxy for physical closeness (proximity), as they attempt with varying success to put positive charged items closer to, or negative and neutral charge items further away from, themselves

    Evaluation of a Commercial Enzyme Linked Immunosorbent Assay (ELISA) for the Determination of the Neurotoxin BMAA in Surface Waters

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    The neurotoxin ß-N-methylamino-L-alanine (BMAA) is suspected to play a role in Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. Because BMAA seems to be produced by cyanobacteria, surface waters are screened for BMAA. However, reliable analysis of BMAA requires specialized and expensive equipment. In 2012, a commercial enzyme-linked immunosorbent assay (ELISA) for determination of BMAA in surface waters was released. This kit could enable fast and relatively cheap screening of surface waters for BMAA. The objective of this study was to determine whether the BMAA ELISA kit was suitable for the determination of BMAA concentrations in surface waters. We hypothesised that the recovery of spiked samples was close to 100% and that the results of unspiked sample analysis were comparable between ELISA and liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. However, we found that recovery was higher than 100% in most spiked samples, highest determined recovery was over 400%. Furthermore, the ELISA gave a positive signal for nearly each tested sample while no BMAA could be detected by LC-MS/MS. We therefore conclude that in its current state, the kit is not suitable for screening surface waters for BMAA

    Enhancement of vaccinia virus based oncolysis with histone deacetylase inhibitors

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    Histone deacetylase inhibitors (HDI) dampen cellular innate immune response by decreasing interferon production and have been shown to increase the growth of vesicular stomatitis virus and HSV. As attenuated tumour-selective oncolytic vaccinia viruses (VV) are already undergoing clinical evaluation, the goal of this study is to determine whether HDI can also enhance the potency of these poxviruses in infection-resistant cancer cell lines. Multiple HDIs were tested and Trichostatin A (TSA) was found to potently enhance the spread and replication of a tumour selective vaccinia virus in several infection-resistant cancer cell lines. TSA significantly decreased the number of lung metastases in a syngeneic B16F10LacZ lung metastasis model yet did not increase the replication of vaccinia in normal tissues. The combination of TSA and VV increased survival of mice harbouring human HCT116 colon tumour xenografts as compared to mice treated with either agent alone. We conclude that TSA can selectively and effectively enhance the replication and spread of oncolytic vaccinia virus in cancer cells. © 2010 MacTavish et al

    L-Arginine promotes gut hormone release and reduces food intake in rodents

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    Aims: To investigate the anorectic effect of L‐arginine (L‐Arg) in rodents. Methods: We investigated the effects of L‐Arg on food intake, and the role of the anorectic gut hormones glucagon‐like peptide‐1 (GLP‐1) and peptide YY (PYY), the G‐protein‐coupled receptor family C group 6 member A (GPRC6A) and the vagus nerve in mediating these effects in rodents. Results: Oral gavage of L‐Arg reduced food intake in rodents, and chronically reduced cumulative food intake in diet‐induced obese mice. Lack of the GPRC6A in mice and subdiaphragmatic vagal deafferentation in rats did not influence these anorectic effects. L‐Arg stimulated GLP‐1 and PYY release in vitro and in vivo. Pharmacological blockade of GLP‐1 and PYY receptors did not influence the anorectic effect of L‐Arg. L‐Arg‐mediated PYY release modulated net ion transport across the gut mucosa. Intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) administration of L‐Arg suppressed food intake in rats. Conclusions: L‐Arg reduced food intake and stimulated gut hormone release in rodents. The anorectic effect of L‐Arg is unlikely to be mediated by GLP‐1 and PYY, does not require GPRC6A signalling and is not mediated via the vagus. I.c.v. and i.p. administration of L‐Arg suppressed food intake in rats, suggesting that L‐Arg may act on the brain to influence food intake. Further work is required to determine the mechanisms by which L‐Arg suppresses food intake and its utility in the treatment of obesity
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