Chromogranin A in the olfactory system of the rat

The olfactory bulb of the rat contains chromogranin A at a similar level as the adrenal gland or the hypophysis as revealed by immunoblots. Olfactory chromogranin A also displays the same size as chromogranin A of endocrine cells. In the hippocampus and other brain regions, we could not detect chromogranin A by immunoblotting. In contrast, chromogranin A messenger ribonucleic acid (using S1 nuclease protection assays) was observed in all brain regions examined, including the olfactory bulb. By in situ hybridization histochemistry with a complementary ribonucleic acid probe (280 nucleotides), and by immunocytochemistry, chromogranin A synthesis could be localized to cell bodies of the mitral cell layer, of the external plexiform layer and of the periglomerular region of the olfactory bulb. Immunocytochemically, chromogranin A was also detected in the central projection areas of mitral and tufted cells in the primary olfactory cortex and the anterior amygdaloid area but not in the olfactory glomeruli, where the incoming olfactory nerve fibers of the primary olfactory neurons establish synaptic contacts. Taken together the data show that chromogranin A, following biosynthesis in the perikarya of the mitral and tufted cells, is specifically transported into their axonal terminals but not into their primary dendrites. We propose that the rat olfactory system could serve as a model for the study of chromogranin A regulation and function in neurons

Assessing the perceived realism of agent grouping dynamics for adaptation and simulation

Virtual crowds are a prominent feature for a range of applications; from simulations for cultural heritage, to interactive elements in video games. A body of existing research seeks to develop and improve algorithms for crowd simulation, typically with a goal of achieving more realistic behaviours. For applications targeting human interaction however, what is judged as realistic crowd behaviour can be subjective, leading to situations where actual crowd data is not always perceived to be more real than simulation, making it difficult to identify a ground truth. We present a novel method using psychophysics to assess the perceived realism of behavioural features with respect to virtual crowds. In this instance, a focus is given to the grouping dynamics feature, whereby crowd composition in terms of group frequency and density is evaluated through thirty-six conditions based on crowd data captured from three pedestrianised real-world locations. The study, conducted with seventy-eight healthy participants, allowed for the calculation of perceptual thresholds, with configurations identified that appear most real to human viewers. The majority of these configurations correlate with the values extracted from the crowd data, with results suggesting that viewers have more perceptual flexibility when group frequency and density are increased, rather than decreased.</p

Modelling gap junction-coupled networks of olfactory bulb mitral cells

Summary of Thesis: The olfactory bulb forms the first level of input integration for olfactory receptor neurons that receive stimuli from odorant molecules in the nose. The olfactory bulb is multi channel in nature, with each channel containing its own populations of mitral cells. These channels each handle the input from neurons expressing a single type of olfactory receptor protein tuned to a unique range of odorant structures. I have constructed a mitral cell gap-junction network model with morphologically accurate mitral cells to study the behaviour of mitral cells in a channel population. The passive parameters of each of the mitral cells were determined by fitting to in vitro recordings. Sodium and potassium channels were added to the mitral cells to give the ability to generate action potentials. Gap-junctions were placed in the apical dendrite tufts of the mitral cells and their conductance adjusted to give a coupling ratio between mitral cells consistent with experimental findings. Firing was induced with twenty current injections randomly located in the apical dendrite tuft of two of the mitral cells, mimicking the multiple inputs from the olfactory receptor neurons. A protocol was used to promote an initial asynchrony in firing which was transmitted across the gap-junctions to all six mitral cells. I found that the mitral cell population would overcome this asynchrony, rapidly tending to synchronous firing. Adding calcium and calcium dependent potassium channels to the mitral cells produced burst firing patterns that were different for each of the cells. The gap-junctions did not have enough influence to overcome the asynchrony of the different burst firing patterns. The addition of calcium concentration threshold dependant glutamate release and AMPA auto receptors to the apical dendrite tuft of each mitral cell allowed the burst firing to promote self propagating synchronised firing after an initial period of asynchrony

Scoping studies to establish the capability and utility of a real-time bioaerosol sensor to characterise emissions from environmental sources

A novel dual excitation wavelength based bioaerosol sensor with multiple fluorescence bands called Spectral Intensity Bioaerosol Sensor (SIBS) has been assessed across five contrasting outdoor environments. The mean concentrations of total and fluorescent particles across the sites were highly variable being the highest at the agricultural farm (2.6 cm−3 and 0.48 cm−3, respectively) and the composting site (2.32 cm−3 and 0.46 cm−3, respectively) and the lowest at the dairy farm (1.03 cm−3 and 0.24 cm−3, respectively) and the sewage treatment works (1.03 cm−3 and 0.25 cm−3, respectively). In contrast, the number-weighted fluorescent fraction was lowest at the agricultural site (0.18) in comparison to the other sites indicating high variability in nature and magnitude of emissions from environmental sources. The fluorescence emissions data demonstrated that the spectra at different sites were multimodal with intensity differences largely at wavelengths located in secondary emission peaks for λex 280 and λex 370. This finding suggests differences in the molecular composition of emissions at these sites which can help to identify distinct fluorescence signature of different environmental sources. Overall this study demonstrated that SIBS provides additional spectral information compared to existing instruments and capability to resolve spectrally integrated signals from relevant biological fluorophores could improve selectivity and thus enhance discrimination and classification strategies for real-time characterisation of bioaerosols from environmental sources. However, detailed lab-based measurements in conjunction with real-world studies and improved numerical methods are required to optimise and validate these highly resolved spectral signatures with respect to the diverse atmospherically relevant biological fluorophores

Integrating the Theory of Sampling into Underground Mine Grade Control Strategies

Grade control in underground mines aims to deliver quality tonnes to the process plant via the accurate definition of ore and waste. It comprises a decision-making process including data collection and interpretation; local estimation; development and mining supervision; ore and waste destination tracking; and stockpile management. The foundation of any grade control programme is that of high-quality samples collected in a geological context. The requirement for quality samples has long been recognised, where they should be representative and fit-for-purpose. Once a sampling error is introduced, it propagates through all subsequent processes contributing to data uncertainty, which leads to poor decisions and financial loss. Proper application of the Theory of Sampling reduces errors during sample collection, preparation, and assaying. To achieve quality, sampling techniques must minimise delimitation, extraction, and preparation errors. Underground sampling methods include linear (chip and channel), grab (broken rock), and drill-based samples. Grade control staff should be well-trained and motivated, and operating staff should understand the critical need for grade control. Sampling must always be undertaken with a strong focus on safety and alternatives sought if the risk to humans is high. A quality control/quality assurance programme must be implemented, particularly when samples contribute to a reserve estimate. This paper assesses grade control sampling with emphasis on underground gold operations and presents recommendations for optimal practice through the application of the Theory of Sampling

The cross-sectional association between snacking behaviour and measures of adiposity: the Fenland Study, UK.

Unhealthy dietary behaviours may contribute to obesity along with energy imbalance. Both positive and null associations of snacking and BMI have been reported, but the association between snacking and total adiposity or pattern of fat deposition remains unevaluated. The objective of this study was to investigate the associations between snacking frequency and detailed adiposity measurements. A total of 10 092 adults residing in Cambridgeshire, England, self-completed eating pattern snacking frequency, FFQ and physical activity questionnaires. Measurements included anthropometry, body composition using dual-energy X-ray absorptiometry scan and ultrasound and assessment of physical activity energy expenditure using heart rate and movement sensing. Linear regression analyses were conducted adjusted for age, socio-demographics, dietary quality, energy intake, PAEE and screen time by sex and BMI status. Among normal-weight individuals (BMI<25 kg/m2), each additional snack was inversely associated with obesity measures: lower total body fat in men and women (-0·41 (95 % CI -0·74, -0·07) %, -0·41 (-0·67, -0·15) %, respectively) and waist circumference (-0·52 (-0·90, -0·14) cm) in men. In contrast, among the overweight/obese (BMI≥25 kg/m2), there were positive associations: higher waist circumference (0·80 (0·34, 0·28) cm) and subcutaneous fat (0·06 (0·01, 0·110) cm) in women and waist circumference (0·37 (0·00, 0·73) cm) in men. Comparing intakes of snack-type foods showed that participants with BMI≥25 kg/m2 had higher intakes of crisps, sweets, chocolates and ice-creams and lower intakes of yoghurt and nuts compared with normal-weight participants. Adjusting for these foods in a model that included a BMI-snacking interaction term attenuated all the associations to null. Snacking frequency may be associated with higher or lower adiposity, with the direction of association being differential by BMI status and dependent on snack food choice. Improving snack choices could contribute to anti-obesity public health interventions.The Fenland Study is funded by the Wellcome Trust and the Medical Research Council. Support from Medical Research Council programmes MC_UU_12015/1 and MC_UU_12015/5 is acknowledged.This is the final version of the article. It first appeared from British Journal of Nutrition via http://dx.doi.org/10.1017/S000711451500269

A Neural Network for Interpolating Light-Sources

This study combines two novel deterministic methods with a Convolutional Neural Network to develop a machine learning method that is aware of directionality of light in images. The first method detects shadows in terrestrial images by using a sliding-window algorithm that extracts specific hue and value features in an image. The second method interpolates light-sources by utilising a line-algorithm, which detects the direction of light sources in the image. Both of these methods are single-image solutions and employ deterministic methods to calculate the values from the image alone, without the need for illumination-models. They extract real-time geometry from the light source in an image, rather than mapping an illumination-model onto the image, which are the only models used today. Finally, those outputs are used to train a Convolutional Neural Network. This displays greater accuracy than previous methods for shadow detection and can predict light source-direction and thus orientation accurately, which is a considerable innovation for an unsupervised CNN. It is significantly faster than the deterministic methods. We also present a reference dataset for the problem of shadow and light direction detection. © 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

Systematic review of the evidence on orthotic devices for the management of knee instability related to neuromuscular and central nervous system disorders

Objectives To assess the effectiveness of orthotic devices for the management of instability of the knee in adults with a neuromuscular disorder or central nervous system disorder. Design A systematic review of primary studies. Setting Community. Participants Adults with a neuromuscular disorder or central nervous system disorder and impaired walking ability due to instability of the knee. Interventions Orthoses with the clinical aim of controlling knee instability, for example, knee-ankle-foot orthoses, ankle-foot orthoses and knee orthoses or mixed design with no restrictions in design or material. Primary and secondary outcome measures Conditionspecific or generic patient-reported outcome measures assessing function, disability, independence, activities of daily living, quality of life or psychosocial outcomes; pain; walking ability; functional assessments; biomechanical analysis; adverse effects; usage; patient satisfaction and the acceptability of a device; and resource utilisation data. Results Twenty-one studies including 478 patients were included. Orthotic devices were evaluated in patients with postpolio syndrome, poststroke syndrome, inclusion body myositis and spinal cord injury. The review included 2 randomised controlled trials (RCTs), 3 non-randomised controlled studies and 16 case series. Most were small, single-centre studies with only 6 of 21 following patients for 1 year or longer. They met between one and five of nine quality criteria and reported methods and results poorly. They mainly assessed outcomes related to gait analysis and energy consumption with limited use of standardised, validated, patient-reported outcome measures. There was an absence of evidence on outcomes of direct importance to patients such as reduction in pain and falls. Conclusions There is a need for high-quality research, particularly RCTs, of orthotic devices for knee instability related to neuromuscular and central nervous system conditions. This research should address outcomes important to patients. There may also be value in developing a national registr