Investigation of the brain magnetisation transfer ratio, cognitive and neurological measures in prion disease

The work described in this thesis examines the application of magnetisation transfer ratio (MTR) measurement, a quantitative magnetic resonance imaging (MRI) technique, in evaluating patients with different forms of human prion disease. In particular whether MTR changes can be shown: 1. to correlate with clinical disease severity and disease type 2. to evolve on serial MRIs in clinically progressive disease 26 patients were assessed over 3 years. Global and regional cerebral MTRs were calculated using validated software and regions of interest manually defined on MTR maps. Whole brain, grey matter and white matter MTR histograms were computed and mean, peak height, peak location, and 25th, 50th and 75th percentile MTR histogram values were calculated to demonstrate localised and subtle diffuse pathological changes. A blinded assessment of DWI/FLAIR images was performed to determine MTR changes in areas with or without signal change on conventional MRI. Patients were assessed using clinical video scores and neurological scales: Clinician's Global Impression of Disease Severity, Clinician's Dementia Rating, Alzheimer's disease Assessment Scale, Activities of Daily Living, Brief Psychiatric Rating Scale, Mini Mental Score Examination, Glasgow Coma Score and Rankin scores. Temporal changes in these tests of cognition, functional abilities, psychiatric symptoms and conscious state are described. Spearman rank correlation and linear regression analyses were performed. At baseline, lower whole brain and grey matter MTR histogram parameters correlated significantly with lower cognitive, extrapyramidal and cerebellar impairment, as well as with MMSE, CDR, ADAS-COG, CGIS and Rankin scores. Longitudinal decline in multiple whole brain, white matter and grey matter MTR histogram parameters was associated with progressive extrapyramidal and CDR impairment. Four patients at baseline and 2 patients longitudinally had conventional MRI abnormalities. Decreased MTR may be used as a biomarker of disease severity and is a potential outcome measure in future therapeutic trials in prion disease

Genomic characterization of antibiotic resistant Escherichia coli isolated from domestic chickens in Pakistan

Poultry husbandry is important for the economic health of Pakistan, but the Pakistani poultry industry is negatively impacted by infections fro

Super-reflection of light from a random amplifying medium with disorder in the complex refractive index : Statistics of fluctuations

The probability distribution of the reflection coefficient for light reflected from a one-dimensional random amplifying medium with {\it cross-correlated} spatial disorder in the real and the imaginary parts of the refractive index is derived using the method of invariant imbedding. The statistics of fluctuations have been obtained for both the correlated telegraph noise and the Gaussian white-noise models for the disorder. In both cases, an enhanced backscattering (super-reflection with reflection coefficient greater than unity) results because of coherent feedback due to Anderson localization and coherent amplification in the medium. The results show that the effect of randomness in the imaginary part of the refractive index on localization and super-reflection is qualitatively different.Comment: RevTex 6 pages, 3 figures in ps file

Pharmacists and telemedicine: an innovative model fulfilling Sustainable Development Goals (SDGs)

The lack of access to safe medicines and quality healthcare services in peri-urban and rural areas is a major challenge driving a health system to innovate new models of care. This commentary will discuss the implementation and impact of the “Guddi baji” tele-pharmacy model, a project piloted by doctHERs, one of Pakistan’s leading telemedicine organizations. This innovative model has described the reintegration of women into the workforce by leveraging technology to improve the level of primary health care services and contributes to safe medication practice in a remote area. Our intervention proposed the deployment of technology-enabled, female frontline health workers known as the Guddi baji (meaning The Good Sister) in a rural village. They serve as an “access point to health care” that is linked to a remotely located health care professional; a licensed doctor or a pharmacist within this model

Improved extractability of carotenoids from tomato peels as side benefits of PEF treatment of tomato fruit for more energy-efficient steam-assisted peeling

Abstract The combination of steam blanching (SB) with Pulsed Electric Fields (PEF) treatments of whole tomatoes, in addition to reducing the energy required for tomato peeling, can significantly contribute to the recovery of carotenoids from the peels. In this work, PEF (0.25-0-75 kV/cm, 1 kJ/kg) and SB (1 min at 50–70 °C), as pre-treatment prior to hand peeling, were investigated to assess their ability, separately and in combination, to induce the cell permeabilization of tomato peels, and hence to improve the carotenoids extraction in acetone (4 h at 25 °C). PEF and SB, by inducing significant damages at the cuticular level, caused the increase of the yield in total carotenoids (up to 188% for PEF and 189% for SB) and antioxidant power (up to 372% for PEF and 305% for SB) with respect to the peels from untreated tomatoes. The application of a combined treatment (PEF + SB) significantly increased the carotenoid content and the antioxidant power of the extracts, with a synergistic effect observed already at 60 °C (37.9 mg/100 g fresh weight tomato peels). HPLC analyses revealed that lycopene was the main carotenoid extracted and that neither PEF nor SB caused any selective release or degradation of lycopene. Results obtained from this study demonstrate that the integration of PEF in the processing line of tomato fruits prior to SB contributes to the valorization of tomato processing by-products

Faba bean (Vicia faba L.) seeds darken rapidly and phenolic content falls when stored at higher temperature, moisture and light intensity

Faba beans cv. Fiesta with seed moisture content (SMC) modified to 8, 10, 12 and 14% were packed in polyethylene lined aluminium foil bags and stored at 5, 15, 20, 25, 30, 37, 45, 50 or 60 C ( 2 C) for one year. Samples were analysed for moisture content and seed coat (testa) colour over the storage period using a chroma meter. A continuous increase in L* and b* values was found in all samples with the passage of time whereas a *values first increased and then decreased in samples stored at relatively high temperatures (= 37 C). The initial beige testa colour changed to light brown, dark reddish brown or almost black depending on storage conditions. The higher the temperature and SMC the faster the rate of change in colour (E ab* values). Seeds with 8% SMC had more stable testa colour compared to seeds with higher SMC. Exposure to artificial light (350 mol m -2 s -1) substantially accelerated the colour darkening. Cotyledon stored at 37+2 C also darkened with the storage time. A loss in total free phenolics, total tannins and proanthocyanidins was found with increased darkness of testa and cotyledons during storage

Modelling Li+ Ion Battery Electrode Properties

We formulated two detailed models for an electrolytic cell with particulate electrodes based on a lithium atom concentration dependent Butler-Volmer condition at the interface between electrode particles and the electrolyte. The first was based on a dilute-ion assumption for the electrolyte, while the second assumed that Li ions are present in excess. For the first, we used the method of multiple scales to homogenize this model over the microstructure, formed by the small lithium particles in the electrodes. For the second, we gave rigorous bounds for the effective electrochemical conductivity for a linearized case. We expect similar results and bounds for the "full nonlinear problem" because variational results are generally not adversely affected by a sinh term. Finally we used the asymptotic methods, based on parameters estimated from the literature, to attain a greatly simplified one-dimensional version of the original homogenized model. This simplified model accounts for the fact that diffusion of lithium atoms within individual electrode particles is relatively much faster than that of lithium ions across the whole cell so that lithium ion diffusion is what limits the performance of the battery. However, since most of the potential drop occurs across the Debye layers surrounding each electrode particle, lithium ion diffusion only significantly affects cell performance if there is more or less complete depletion of lithium ions in some region of the electrolyte which causes a break in the current flowing across the cell. This causes catastrophic failure. Providing such failure does not occur the potential drop across the cell is determined by the concentration of lithium atoms in the electrode particles. Within each electrode lithium atom concentration is, to leading order, a function of time only and not of position within the electrode. The depletion of electrode lithium atom concentration is directly proportional to the current being drawn off the cell. This leads one to expect that the potential of the cell gradually drops as current is drawn of it. We would like to emphasize that all the homogenization methods employed in this work give a systematic approach for investigating the effect that changes in the microstructure have on the behaviour of the battery. However, due to lack of time, we have not used this method to investigate particular particle geometries

Differential physio-biochemical and metabolic responses of peanut (Arachis hypogaea L.) under multiple abiotic stress conditions

The frequency and severity of extreme climatic conditions such as drought, salinity, cold, and heat are increasing due to climate change. Moreover, in the field, plants are affected by multiple abiotic stresses simultaneously or sequentially. Thus, it is imperative to compare the effects of stress combinations on crop plants relative to individual stresses. This study investigated the differential regulation of physio-biochemical and metabolomics parameters in peanut (Arachis hypogaea L.) under individual (salt, drought, cold, and heat) and combined stress treatments using multivariate correlation analysis. The results showed that combined heat, salt, and drought stress compounds the stress effect of individual stresses. Combined stresses that included heat had the highest electrolyte leakage and lowest relative water content. Lipid peroxidation and chlorophyll contents did not significantly change under combined stresses. Biochemical parameters, such as free amino acids, polyphenol, starch, and sugars, significantly changed under combined stresses compared to individual stresses. Free amino acids increased under combined stresses that included heat; starch, sugars, and polyphenols increased under combined stresses that included drought; proline concentration increased under combined stresses that included salt. Metabolomics data that were obtained under different individual and combined stresses can be used to identify molecular phenotypes that are involved in the acclimation response of plants under changing abiotic stress conditions. Peanut metabolomics identified 160 metabolites, including amino acids, sugars, sugar alcohols, organic acids, fatty acids, sugar acids, and other organic compounds. Pathway enrichment analysis revealed that abiotic stresses significantly affected amino acid, amino sugar, and sugar metabolism. The stress treatments affected the metabolites that were associated with the tricarboxylic acid (TCA) and urea cycles and associated amino acid biosynthesis pathway intermediates. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and heatmap analysis identified potential marker metabolites (pinitol, malic acid, and xylopyranose) that were associated with abiotic stress combinations, which could be used in breeding efforts to develop peanut cultivars that are resilient to climate change. The study will also facilitate researchers to explore different stress indicators to identify resistant cultivars for future crop improvement programs

Experiments on grain yield in a range of old and modern wheat varieties.

Growth, yield, water use and water use efficiency of old and modern wheat varieties in a mediterranean type environment, 87M17 and 87WH14. Ear and stem dry matter at anthesis and grain yield in a range of wheat varieties, 87M18