76 research outputs found
Effect of Curing On the Strength Behaviour of Lime-Fly Ashexpansive Soil Mixes
Expansive soils occupying almost 3 lakh km2 in the Indian subcontinent found to be highly
problematic due to their extensive swelling and shrinkage nature. This rapid volume change leads to upliftment of
foundations, differential settlements, heaving, rutting, etc. on the overlying structures. Concerning with the above
problems an effective, economical and long-term method lime stabilisation was selected. In this work it is attempted
to study the effect of curing period on the strength behaviour expansive soil treated with lime and fly ash by
conducting triaxial shear (UU) test for 0, 3, 7, 14, 28 days with some twenty different proportions
Improved controller design for two-input-two-output (TITO) unstable processes
Controller design for unstable processes is relatively difficult when compared to stable processes. The complexity increases further for multivariable unstable processes. In this work, simplified tuning rules are proposed to design PID controller for unstable multivariable processes. Decouplers are applied to make the loops independent and diagonal elements of equivalent transfer function are used to design controllers. For this, the decoupler design procedure proposed by Hazarika and Chidambaram [10] is used. Two theoretical examples of TITO unstable processes with time delays are considered for simulation. Comparative analysis has been carried out with the recently reported methods in the literature and observed that the proposed method provides improved closed loop performances. Robustness studies are also carried out with various perturbations in the processes
Bearing Capacity of A Strip Footing Resting On Treated And Untreated Soils
Expansive soils are highly susceptible to volumetric changes leading to rapid loss in the bearing
capacity of footings resting on them. Among several techniques available to treat expansive soils, lime or fly ash
stabilization gained prominence during the past few decades due to its abundance and adaptability. Chemical
stabilization is widely used to treat expansive soils as it develops base exchange and cementation processes between
clay particles.When expansive soils are treated with chemicals, it is essential to obtain the load-settlement response
of footing resting on stabilized ground. In this study, Finite Element Analysis is performed using the commercial
software, PLAXIS 2D, to obtain the load-settlement response of a strip footing resting on untreated and treated
expansive soil. The bearing capacity of strip footing resting on treated soil is found to be about 150% higher than
that of footing resting on untreated soil
PACLITAXEL DISPOSITION STUDIES USING P-GP INHIBTOR & INDUCER BY SINGLE PASS INTESTINAL PERFUSION IN RATS
Objective:
The present research work aims to study the intestinal transport of Paclitaxel and to predict its human intestinal permeability and fraction absorbed using SPIP Permeability Coefficient and the effect of P-gp modulators on Paclitaxel were observed in anaesthetized rats.
Methods:
Jejunal segment was used for performing Single Pass Intestinal Perfusion. The rationale for the selection of jejenum is due to the overexpression of P-glycoprotein when compared with other segments. Drug solution (150µg/ml) in phosphate buffer saline was perfused at a flow rate of 0.2ml/min.Besides,P-gp inhibitor verapamil(200 µg/ml) and inducer Rifampicin (60mg/ml) were coperfused with Paclitaxel to detect its disposition characteristics affected by P-gp .Drug concentrations in samples were analyzed using HPLC. Stability studies were conducted to ensure the loss of Paclitaxel due to absorption.
Results:
The effective permeability value of Paclitaxel (150µg/ml) in the jejunal segment was found to be lower due to the efflux mediated by P-gp.When coperfused with verapamil its permeability significantly enhanced as it is a P-gp inhibitor and vice versa with Rifampicin which is a P-gp inducer. Subsequently the human intestinal permeability was estimated considering Peff(human) =1.04 Peff(rat)-0.0003.
Conclusion:
P-Glycoprotein mediated drug resistance is one of the serious limitations of Paclitaxel efficacy and jejunal segment is found to have major MDR expression. The Peff value of Paclitaxel was found to be increased upon the Coperfusion with verapamil and similarly reduced with Rifampicin which are inhibitors & inducers respectively indicating Paclitaxel is efficiently transported by P-gp. Hence, Paclitaxel satisfies all the prerequisites to be a P-gp substrate.
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Keywords: Paclitaxel, Intestinal permeability, Single pass intestinal perfusion, P-glycoprotein, RP-HPLC
Slider User Interface with Precise Value Selection Using Gestures
Sliders are user interface elements that enable users to view and select values from a predefined range along a horizontal or vertical bar. Values on a slider are usually incremented with preset multipliers. When a user wants to select a value that requires precision that is not supported by the preset multipliers, the user is not able to achieve the desired accuracy. Such limitations are due to the limited amount of physical space and/or touch sensitivity available for interactions such as tapping or swiping. This disclosure describes a slider user interface that enables users to fine tune value selection using finger interactions (or equivalent) without requiring the use of a keyboard or other auxiliary mechanism. Per the techniques, the user can grab the slider knob (e.g., via touch and hold) and drag it at different angles to access multipliers with different levels of precision. The distance from the initial position is used to determine the selected value
Resistance Factor Calculations for Load Resistance Factor Design (LRFD) of MSW Landfill Slopes
It is obvious to note that there is a significant amount of variability connected with shear parameters of municipal solid waste (MSW) landfills. To ensure uniform safety and reliability, the design approaches in the US have progressively transformed to the load and resistance factor design (LRFD) format. It may be desirable to the successful development and adoption of reliability-based resistance factors for the design of landfill slopes taking into account the significant variability of shear strength parameters. The exhaustive studies reported on shear parameters of MSW are compiled and reviewed. The mean, standard deviation, and coefficient of variation (COV) associated with shear parameters are obtained using statistical analysis. The probability density functions (PDFs) are plotted for unit weight, cohesion, and friction angle. The PDFs show that high range of variability associated with shear parameters and should be given due consideration in the optimum designs. Therefore, the present work reports a procedure for determining the resistance factors for stability number (in terms of unit weight, cohesion) and friction angle of MSW in accordance with LRFD of MSW landfill slopes that target a specific reliability index. A simple first-order reliability method (FORM) is reported to compute the ranges for the resistance factors. Perhaps, this is the first study to propose resistance factors for the design of MSW slopes. The stability number (in terms of unit weight, cohesion) and friction angle of the MSW are treated as random variables. The Spencer method of slices has been employed to formulate the performance function against the sliding failure of finite slopes. It is illustrated that the uniform safety levels can be obtained by using the proposed resistance factors
Computation of the Probabilistic Critical Centers and Reliability Indices of MSW Landfill Slopes Using the Spencer Method of Slices
The shear strength properties of Municipal Solid Waste (MSW) are of special importance when evaluating the stability of landfill slopes. Geoenvironmental engineers are well aware of the existence of many sources of uncertainties associated with shear strength parameters of MSW due to various reasons. The significant uncertainties associated with the shear strength and shear stresses render deterministic modeling potentially misleading. The traditional engineering approaches like method of slices used for evaluating MSW slopes are frequently questionable as they do not adequately account for uncertainties included in analytical modeling and natural variability. In order to quantify the slope stability precisely by taking into account the variability, the Reliability Based Design Optimization (RBDO) framework is presented. The mean and standard deviations associated with unit weight, cohesion and angle of internal friction of the MSW are taken into account in the probabilistic optimization. Reliability analysis is performed using first order reliability method (FORM). A limit state function is formulated against sliding slope failure using Spencer method of slices. The influence of coefficients of variation (COV) of stability number and friction angle on critical center coordinates and reliability index is presented in the form of charts
SELECTIVE CECAL BACTERIAL CHANGES MEDIATE THE ADVERSE EFFECTS ASSOCIATED WITH HIGH PALMOLEIN OR HIGH STARCH DIETS: PROPHYLACTIC ROLE OF FLAX OIL
Objective: Studies on the dynamics of gut bacteria in relation to metabolic adverse effects induced by high palmolein or high starch diets and in relation to health benefits of uncommon foods are lacking. Our aim was to assess under controlled conditions, the impact of vegetable based palmitic acid rich, high fat diet or a high starch diet on various metabolic parameters in relation to selective gut bacterial alterations in rats and also to see the effect of flaxseed oil supplementation on these parameters.Methods: Wistar Rats were fed for 4 mo either a control diet(CT) or a 30% high fat diet (HF) or HF diet with flax oil supplemented at two different doses (HFF1 and HFF2) or a 78% high starch diet (HC) after which they were sacrificed and analyzed for selective cecal bacteria, hematology, immune function and body composition.Results: High palmolein diet fed rats showed a decrease in colony forming units of lactobacillus, enterococci, streptococci bacteria and an increase in enterobacteriaceae in the cecum unlike HC fed rats. While high palmolein diet was found to impair immunity and increase inflammation, high starch diet affected body composition and lipid profile. Supplementing the flax seed oil ameliorated most of the adverse effects of high palmolein diet.Conclusions: Independent of energy intakes both high palmolein and high starch intakes have differential adverse effects. It can be envisaged that the adverse effects of feeding palmolein are mediated through immune impairment and inflammatory response, which in turn are associated with altered gut bacteria profile; and flax oil was found to have a prophylactic role in controlling these adverse effects. This study emphasizes the need to evaluate immunological as well as bacterial profile while assessing the safety of dietary fats in addition to traditional methods.Â
The ENIGMA-Epilepsy working group: Mapping disease from large data sets
Epilepsy is a common and serious neurological disorder, with many different constituent conditions characterized by their electro clinical, imaging, and genetic features. MRI has been fundamental in advancing our understanding of brain processes in the epilepsies. Smaller‐scale studies have identified many interesting imaging phenomena, with implications both for understanding pathophysiology and improving clinical care. Through the infrastructure and concepts now well‐established by the ENIGMA Consortium, ENIGMA‐Epilepsy was established to strengthen epilepsy neuroscience by greatly increasing sample sizes, leveraging ideas and methods established in other ENIGMA projects, and generating a body of collaborating scientists and clinicians to drive forward robust research. Here we review published, current, and future projects, that include structural MRI, diffusion tensor imaging (DTI), and resting state functional MRI (rsfMRI), and that employ advanced methods including structural covariance, and event‐based modeling analysis. We explore age of onset‐ and duration‐related features, as well as phenomena‐specific work focusing on particular epilepsy syndromes or phenotypes, multimodal analyses focused on understanding the biology of disease progression, and deep learning approaches. We encourage groups who may be interested in participating to make contact to further grow and develop ENIGMA‐Epilepsy
Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study
Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls. We ranked brain structures in order of greatest differences between patients and controls, by meta-Analysing effect sizes across 16 subcortical and 68 cortical brain regions. We also tested effects of duration of disease, age at onset, and age-by-diagnosis interactions on structural measures. We observed widespread patterns of altered subcortical volume and reduced cortical grey matter thickness. Compared to controls, all epilepsy groups showed lower volume in the right thalamus (Cohen's d = \uc3\ua2 '0.24 to \uc3\ua2 '0.73; P < 1.49 \uc3\u97 10 \uc3\ua2 '4), and lower thickness in the precentral gyri bilaterally (d = \uc3\ua2 '0.34 to \uc3\ua2 '0.52; P < 4.31 \uc3\u97 10 \uc3\ua2 '6). Both MTLE subgroups showed profound volume reduction in the ipsilateral hippocampus (d = \uc3\ua2 '1.73 to \uc3\ua2 '1.91, P < 1.4 \uc3\u97 10 \uc3\ua2 '19), and lower thickness in extrahippocampal cortical regions, including the precentral and paracentral gyri, compared to controls (d = \uc3\ua2 '0.36 to \uc3\ua2 '0.52; P < 1.49 \uc3\u97 10 \uc3\ua2 '4). Thickness differences of the ipsilateral temporopolar, parahippocampal, entorhinal, and fusiform gyri, contralateral pars triangularis, and bilateral precuneus, superior frontal and caudal middle frontal gyri were observed in left, but not right, MTLE (d = \uc3\ua2 '0.29 to \uc3\ua2 '0.54; P < 1.49 \uc3\u97 10 \uc3\ua2 '4). Contrastingly, thickness differences of the ipsilateral pars opercularis, and contralateral transverse temporal gyrus, were observed in right, but not left, MTLE (d = \uc3\ua2 '0.27 to \uc3\ua2 '0.51; P < 1.49 \uc3\u97 10 \uc3\ua2 '4). Lower subcortical volume and cortical thickness associated with a longer duration of epilepsy in the all-epilepsies, all-other-epilepsies, and right MTLE groups (beta, b < \uc3\ua2 '0.0018; P < 1.49 \uc3\u97 10 \uc3\ua2 '4). In the largest neuroimaging study of epilepsy to date, we provide information on the common epilepsies that could not be realistically acquired in any other way. Our study provides a robust ranking of brain measures that can be further targeted for study in genetic and neuropathological studies. This worldwide initiative identifies patterns of shared grey matter reduction across epilepsy syndromes, and distinctive abnormalities between epilepsy syndromes, which inform our understanding of epilepsy as a network disorder, and indicate that certain epilepsy syndromes involve more widespread structural compromise than previously assumed
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