The Growth and Structure of Double - Diffusive Cells Adjacent to a Side - Wall in a Salt - Stratified Environment

August 15-21, 2004 Measurements are reported of the rate of horizontal extension of the cells in tanks of different lengths with a range of initial salinity gradients and cooling rates (which determine the vertical height of each cell). A simple model for the cell evolution is developed. It predicts that cell growth is dependent on tank length. The mean rate of increase of cell length decreases linearly in time, as does the density gradient inside the cells, supported by both temperature and salinity gradients. The results are found to agree quantitatively with the measurements

Oat Attenuation of Hyperglycemia-Induced Retinal Oxidative Stress and NF-B Activation in Streptozotocin-Induced Diabetic Rats

The overproduction of reactive oxygen species (ROS) plays a central role in the pathogenesis of endothelial damage in diabetes. To assess the effect of oat on experimental diabetic retinopathy, five groups of Albino rats were studied: nondiabetic control, untreated diabetic, and diabetic rats treated with 5%, 10%, and 20% (W/W) oat of the diet for 12 weeks. Novel data were obtained in this study indicating a protective role of oat against oxidative stress and diabetic retinopathy. The effects of oat on parameters of oxidative stress, AGE, and nuclear factor kappa B (NF-B) were assessed by ELISA and NF-B activation by electrophoretic mobility shift assay. Tumor necrosis factor alpha (TNF) and vascular endothelial growth factor (VEGF) were also determined. After 12 weeks of diabetes, oat treatment reduced blood glucose levels, HbA1c, all oxidative stress markers, CML, normalized NF-B activation and TNF expression. Furthermore it reduced VEGF in the diabetic retina by 43% (). In conclusion, oat modulates microvascular damage through normalized pathways downstream of ROS overproduction and reduction of NF-B and its controlled genes activation, which may provide additional endothelial protection

Inhibition of α

Postprandial hyperglycemia is a predisposing factor for vascular dysfunction and organ damage. α-glucosidase is a hydrolytic enzyme that increases the glucose absorption rate and subsequently elevates blood glucose levels. Garlic (Allium sativum L.) is a rich source of several phytonutrients, including thiosulfinate (THIO). The aim of this study was to evaluate the ability of THIO, a potent inhibitor of intestinal α-glucosidase, to reduce postprandial blood glucose. Male albino rats were randomly assigned to five different groups (n=10/group). Group 1 served as the control group. Groups 2–5 were injected intraperitoneally with a single dose of streptozotocin (STZ) to induce diabetes. Group 2 comprised untreated diabetic rats. Groups 3 and 4 contained diabetic rats that were given THIO orally (20 mg/kg body weight/day and 40 mg/kg body weight/day, resp.). Group 5 was the positive control having diabetic rats treated orally with acarbose (10 mg/kg body weight/day; positive control). Diabetic rats treated with THIO displayed a significant blood glucose reduction (p<0.001 and < 0.01 by analysis of variance, resp.) and a significant elevation in insulin compared with that of untreated rats. THIO is an effective noncompetitive intestinal α-glucosidase inhibitor that promotes hypoglycemic action (p<0.001) in STZ-injected rats. THIO is a promising agent for the management of postprandial hyperglycemia

Percolative conductivity in alkaline earth silicate melts and glasses

Ion conducting $(CaO)_x(SiO_2)_{1-x}$ glasses and melts show a threshold behaviour in dc conductivity near $x=x_t=0.50$, with conductivities increasing linearly at $x>x_t$. We show that the behaviour can be traced to a rigid ($x0.50$) elastic phase transition near $x=x_t$. In the floppy phase, conductivity enhancement is traced to increased mobility or diffusion of $Ca^{2+}$ carriers as the modified network elastically softens.Comment: 15 pages, 5 figures. Europhysics Letters (2003), in pres

Report on Scientific advice to TfL on bus driver assault screen modifications due to the Covid-19 pandemic

In April 2020 Transport for London (TfL) commissioned the UCL Department of Civil, Environmental and Geomatic Engineering (CEGE) to explore measures to mitigate the occupational risk posed to London bus drivers from the COVID-19 pandemic, following the tragic deaths of a number of drivers among bus operators within London. A separate study undertaken by UCL’s Institute of Health Equality has examined more comprehensively a number of other risk factors affecting bus drivers, including beyond their occupational risk. Phase one of that study was published on the 27th July 2020 and has determined that “there is evidence that among bus drivers those aged 65 and over, those from BAME backgrounds and those with pre-existing hypertension are at a higher risk of COVID-19 mortality and this should be taken into accounts in efforts by TfL and bus companies to reduce risks”. TfL asked UCL CEGE to explore the nature of this occupational risk in relation to the interaction between passengers and the bus driver, and the effects arising as a result of the design of the bus itself, in particular the assault screen. The assault screen is a pre-existing transparent polycarbonate fixture designed to resist physical attacks, such as stabbings, while allowing the driver to have both a clear view through the screen, access the electronic ticket machine and provide receipts when required, and the ability to be able to hear and speak to passengers as the need arises. It was not originally designed to keep the driver completely isolated from the passengers. A set of detailed models was created of the front part of a typical London bus, including both front and central doors, the driver’s cabin and a detailed dynamic model of the bus driver, and then detailed CFD simulations were carried out. These calculated the motion of aerosols emanating from a passenger who is coughing and breathing in a number of positions relative to the driver’s cabin under a variety of design and operational scenarios in order to identify appropriate interventions. A typical screen and bus design were chosen for the simulations, that addressed all the relevant design issues - gaps, door and window operations - as a representative case for all buses. The original (pre-COVID) designs of polycarbonate dividers or screens were only marginally protective against aerosols and were not sufficient on their own to protect against airborne transmission of SARS-CoV-2. A set of recommendations has been made with the aim of reducing this risk to London drivers in particular as much as is practically possible, further to interventions already initiated by TfL. Buses in large cities are a unique indoor environment that is confined and often crowded at rush hour or in tourist season and, if poorly ventilated there is potential for airborne transmission of infectious diseases which may pose a risk to drivers due to their prolonged exposure times. Further work is required to determine if there may be a risk to passengers too, if they are on board for long journeys. Regardless of any mechanical or physical interventions to reduce risk, it is recommended that in the medium-term, targets for Indoor Air Quality (IAQ) standards on public transport are developed and adopted. This, due to the high number of daily passengers, some of whom have long journey durations (>1hr if commuting from zones 4 and beyond) and the prevalence of infectious diseases such as influenza and the common cold in the population every winter season, which carry large economic costs and also cost lives. The emergence of highly infectious and more dangerous diseases in the UK and around the world in the past two decades, such as SARS-CoV-2, SARS, H1N1 (swine flu) or MERS, all indicate that it is very timely to invest efforts towards maintaining healthy and safe indoor air on public transport

Oat Protects against Diabetic Nephropathy in Rats via Attenuating Advanced Glycation End Products and Nuclear Factor Kappa B

Oat, a rich source of soluble fiber, was considered to have a possible preventive effect on the progression of diabetic nephropathy. The present study aimed to assess this preventive activity in a rat model of diabetic nephropathy. Adult Wister rats were injected by streptozotocin (65 mg/kg). Animals were fed with normal diet or with a diet containing 20% oat (W/W) for 21 weeks. At the end of 21 weeks, all the kidney tissues were collected for various examinations. Our results suggested that oat could decrease the Scr and glucose level in blood of diabetic rats significantly (), and increase the creatinine clearance (). In histopathological examination, oat-fed rats showed a significant decrease in glomerulus segmented sclerosis and incidence of tubule vacuolar degeneration. By ELISA, we reported that oat feeding resulted in decreasing the levels of IL-6 and AGE in serum and kidney homogenate. In addition, the levels of oxidative stress markers were markedly improved as a result of oat feeding. Furthermore, using EMSA, we showed that oat attenuated the activation of NF-B. Using RT-PCR, we found that oat could downregulate the TGF-1 and RAGE expression at mRNA levels. This study suggests that oat can suppress diabetic nephropathy in rats effectively and may slow down the renal fibrosis by the disruption of the detrimental AGE-RAGE-NFB axis

Effect of fire smoke on some biochemical parameters in firefighters of Saudi Arabia

<p>Abstract</p> <p>Background</p> <p>Firefighters who are facing fires, are frequently exposed to hazardous materials including carbon monoxide, hydrogen cyanide, hydrogen chloride, benzene, sulphur dioxide, etc. This study aimed to evaluate some relevant serum biochemical and blood hematological changes in activity involved firefighters in comparison to normal subjects.</p> <p>Subjects and Methods</p> <p>Two groups of male firefighters volunteered to participate in the study. The first included 28 firefighters from Jeddah, while the second included 21 firefighters from Yanbu, with overall age ranged 20–48 years. An additional group of 23 male non-firefighters volunteered from both cities as normal control subjects, of age range 20–43 years. Blood samples were collected from all volunteer subjects and investigated for some relevant serum biochemical and blood hematological changes.</p> <p>Results</p> <p>The results obtained showed that, there were statistically significant differences in liver function, kidney function, serum lipid profile, cortisol, creatine kinase, lactate dehydrogenase, iron and its biologically active derivatives, and blood picture in firefighters as compared with the normal control group. These results indicate that, fire smoke mainly affects serum biochemical and blood hematological parameters. Such results might point out to the need for more health protective and prophylactic measures to avoid such hazardous health effects that might endanger firefighters under their highly drastic working conditions.</p> <p>Conclusion</p> <p>Besides using of personal protective equipments for firefighters to protect them against exposure to toxic materials of fire smoke, it is recommended that, firefighters must be under continuous medical follow up through a standard timetabled medical laboratory investigations to allow for early detection of any serum biochemical or blood hematological changes that might happen during their active service life and to allow for early treatment whenever necessary.</p

Identification of genes and gene pathways associated with major depressive disorder by integrative brain analysis of rat and human prefrontal cortex transcriptomes

Despite moderate heritability estimates, progress in uncovering the molecular substrate underpinning major depressive disorder (MDD) has been slow. In this study, we used prefrontal cortex (PFC) gene expression from a genetic rat model of MDD to inform probe set prioritization in PFC in a human post-mortem study to uncover genes and gene pathways associated with MDD. Gene expression differences between Flinders sensitive (FSL) and Flinders resistant (FRL) rat lines were statistically evaluated using the RankProd, non-parametric algorithm. Top ranking probe sets in the rat study were subsequently used to prioritize orthologous selection in a human PFC in a case?control post-mortem study on MDD from the Stanley Brain Consortium. Candidate genes in the human post-mortem study were then tested against a matched control sample using the RankProd method. A total of 1767 probe sets were differentially expressed in the PFC between FSL and FRL rat lines at (qless than or equal to0.001). A total of 898 orthologous probe sets was found on Affymetrix?s HG-U95A chip used in the human study. Correcting for the number of multiple, non-independent tests, 20 probe sets were found to be significantly dysregulated between human cases and controls at qless than or equal to0.05. These probe sets tagged the expression profile of 18 human genes (11 upregulated and seven downregulated). Using an integrative rat?human study, a number of convergent genes that may have a role in pathogenesis of MDD were uncovered. Eighty percent of these genes were functionally associated with a key stress response signalling cascade, involving NF-?B (nuclear factor kappa-light-chain-enhancer of activated B cells), AP-1 (activator protein 1) and ERK/MAPK, which has been systematically associated with MDD, neuroplasticity and neurogenesis