148 research outputs found
Women Entrepreneurship in India: A Case Study of Rinkâs Creation of Rinku Lakdawala
The recent advances in technology and the modern Automation world demand the able administration and initiations from the educated women class and dynamic women entrepreneurs, who absolutely vouch for accidental to the economic growth of nations. It is the order of the day where concept of women entrepreneurship programs have to be devised to analysis the market failures and at the same time to abode the afire civic problems by adding a new dimension of Women entrepreneurship for all SMEsâ and advance policies. Entrepreneurship is the basic activity that entails a core basic understanding âMade On Ownâ. In country like India, the business domain and working scenarios are dominated by menfolk only, but women with dynamic changes in the environment, have realized the criticality of survival and coming in par with the men. Women are becoming more assertive, powerful and standing for their rights, freedom and equality in the business domain. They enter small business and entrepreneurial activities that enriches their life for money earning and getting recognition in the society as well. The paper entails the importance of woman entrepreneurship through a case study where her entrepreneurial skills help her to get an identity for herself and be respectful in the eyes of the society. Woman is not confined to home based business, they are equally equipped to work in the mainstream of the business whether it a service or manufacturing unit. Mrs. Rinku Lakdawala of Rinkâs Creation is a great role model to follow where she kept no stones unturned to make herself successful in Textile Industry. Keywords: Women Entrepreneurship, Challenges, Factors, Innovation
Characterization of Groundnut (Arachis hypogaea L.) Germplasm in Relation to Major Foliar Pests and Diseases
Not availabl
The Role of PILJ and Its Structural Domains in the Localization and Function of the CHP Chemosensory System in Pseudomonas Aeruginosa
Bacteria detect environmental signals using membrane-bound methyl-accepting chemotaxis proteins (MCPs), which are part of a larger complex of chemosensory proteins. Pseudomonas aeruginosa has four functionally distinct chemosensory protein complexes. The Chp chemosensory system regulates type IV pili mediated twitching motility and intracellular levels of cAMP by modulating the activity of an adenylate cyclase, CyaB. The Chp system is also proposed to be involved in type IV pili mediated directional twitching motility towards phosphatidylethanolamine (PE). PilJ is the only MCP predicted to be associated with the Chp system. In this study we investigated different domains of PilJ in order to decipher their roles in signal transduction and localization of the Chp chemosensory system.
Our results show that both the periplasmic and transmembrane domains are involved in signal transduction. A PilJ periplasmic domain mutant (PilJÎ74-273) showed a partial but significant decrease in cAMP levels highlighting the importance of this domain in regulation of this phenotype. However, when sufficient intracellular cAMP is provided, twitching motility occurs in the presence or absence of PE independent of the periplasmic domain. To maintain the inner membrane localization while assaying the role of the transmembrane domains of PilJ, Tsr-PilJ chimeric proteins were used. These fusion proteins showed impaired signal transduction. Through localization studies, we discovered that the role of the PilJ transmembrane domains is not limited to signal transduction. Using fluorescence microscopy, an examination of the intracellular localization of C-terminus truncations of PilJ revealed that the second transmembrane domain plays a role in polar localization of PilJ. This is the first report where the localization of a MCP is impacted by a domain other than the cytoplasmic domain. Determining the internal localization cues for this MCP was important as MCPs are reported to be instrumental in chemosensory cluster formation and localization. Indeed, PilJ is needed for PilI foci formation as demonstrated by fluorescence microscopy studies. Taken together, these studies suggest that the PilJ transmembrane domains are important for both signal transduction and localization. Establishing the importance of PilJ for the potential nucleation of the Chp system paves the path for future work to identify potential partners that would directly or indirectly control the polar localization of PilJ
XENOBIOTIC REGULATION OF THE ATP BINDING CASSETTE TRANSPORTER ABCB6 AND ITS SIGNIFICANCE TO HEPATIC HEME HOMEOSTASIS
Heme is indispensable for mammalian life. It is an essential component of numerous heme proteins, with functions including oxygen transport and storage, energy metabolism, drug and steroid metabolism and signal transduction. Under normal physiological conditions intracellular free heme levels are extremely low because increased levels of free heme are cytotoxic and accordingly, heme biosynthesis is tightly regulated. Although, 5-aminolevulinic acid synthase (ALAS) mediated regulation of heme synthesis is considered the key step in heme biosynthesis, recent reports have identified a second regulatory step in heme biosynthesis mediated by the mitochondrial ATP binding cassette transporter b6 (Abcb6). Abcb6 expression is directly related to enhanced de novo porphyrin biosynthesis, and Abcb6 overexpression activates the expression of genes important for heme biosynthesis. Thus, Abcb6 represents a previously unrecognized rate-limiting step in heme biosynthesis. The dissertation outlines the progress made since its initiation in understanding the mechanism(s) that regulate Abcb6 expression and the significance of Abcb6 expression to cellular heme homeostasis. Exposure to therapeutic drugs and environmental contaminants leads to an increase in heme demand to compensate for the increased expression of the heme-dependent cytochrome P450s (P450s) detoxifying enzymes. Cells respond to this increasing heme demand by increasing heme synthesis. Thus, exposure to environmental contaminants serves as an optimal in vivo and in vitro model system to study mechanisms that regulate heme synthesis. In this model, Abcb6 expression was induced in response to exposure to xenobiotics [polyaromatic hydrocarbons (PAHs), 1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) and pregnenolone 16alpha -carbonitrile (PCN)] suggesting a co-ordinate induction of Abcb6 to support the increased heme synthesis. Increased Abcb6 expression in response to cellular heme demands was mediated by the xenobiotic sensing nuclear receptors aryl-hydrocarbon receptor (AhR), the constitutive androstane receptor (CAR), and the pregnane-X receptor (PXR). Exposure to environmental contaminants also leads to the generation of oxidative stress, a primary mechanism by which these compounds cause cellular damage. Cells respond to this increased oxidative stress by activating anti-oxidant defense mechanisms, whose principal components include hemo-proteins (such as catalase, superoxide dismutase, etc). Arsenic, an environmental contaminant and a major hazard following occupational exposure exerts its chronic toxicity through the generation of reactive oxygen species. Of importance, exposure to arsenic also activates the antioxidant defense mechanism. Thus, exposure to arsenic serves as a good model system to evaluate in vivo and in vitro oxidative stress response. In this model system, sodium arsenite induced Abcb6 expression in a dose-dependent manner both in mice fed sodium arsenite in drinking water and in cells exposed to sodium arsenite in vitro. Arsenite-induced Abcb6 expression was transcriptionally regulated but was not mediated by the redox sensitive transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2). The significance of Abcb6 expression to cellular heme homeostasis under conditions of heme demand was evaluated in vitro by both gain of function (cells engineered to overexpress Abcb6) and loss of function (cells where endogenous Abcb6 expression was knocked down using Abcb6 specific ShRNA) analysis. Loss of Abcb6 expression in these in vitro model systems significantly compromises the ability of cells to respond to increased heme demand and the ability to protect against oxidative stress following exposure to environmental contaminants. To understand the significance of Abcb6 function to heme homeostasis in vivo, we generated mice carrying homozygous deletion of the Abcb6 allele (Abcb6 null mice). Abcb6 null animals appear phenotypically normal with a trend towards decreased hepatic heme levels, although, the decreased heme levels did not appear to be statistically significant. Interestingly however, Abcb6 null mice demonstrate genotypic changes that suggest a role for Abcb6 in lipid and cholesterol homeostasis. Abcb6 null mice have increased fasting serum cholesterol and increased accumulation of androstone metabolites. Abcb6 null mice also show decreased expression and activity of a specific set of P450s suggesting a role for Abcb6 in drug metabolism and disposition. Mitochondrial ABC transporters are difficult to study because of the two-membrane architecture of mitochondria, problems associated with analyzing transport process, and the high abundance of other ATPases and carriers/transporters. Thus, the development of an in vitro system with pure and active protein is a prerequisite toward understanding the mechanistic relationships between ATP binding and hydrolysis and coupling of these events to translocation of substrates across the lipid membranes. Towards this end, we developed an in vitro liposomal transport system with pure and active Abcb6 protein. Reconstitution of Abcb6 into liposomes allowed biochemical characterization of the ATPase including (i) substrate stimulated ATPase activity (ii) transport kinetics of its proposed endogenous substrate coproporphyrinogen III and (iii) transport kinetics of substrates identified using a HTS assay. In summary, this dissertation provides insight into the mechanisms that regulate Abcb6 expression in response to increasing heme demand and the in vitro significance of Abcb6 to cellular heme homeostasis. Development of the Abcb6-null mice suggests that loss of Abcb6 does not severely affect heme-dependent functions in the liver probably because of the activation of compensatory mechanisms that balance the loss of Abcb6. More interestingly, Abcb6-null mice show a phenotype that is characteristic of the deficiency of a protein that is involved in cholesterol and lipid homeostasis. Development of the Abcb6-null mice and the development of an in vitro system with purified Abcb6 should serve as useful tools to understand the transport function of Abcb6 and its role in normal and patho-physiology
Embelia ribes extract reduces high fat diet and low dose streptozotocin-induced diabetic nephrotoxicity in rats
Nephropathy associated with type 2 diabetes
is the single most common cause of end-stage
renal disease. The aim of the present study was to evaluate the preventive effect of ethanolic extract of Embelia ribes fruit (EER) against high fat diet (HFD) and low dose streptozotocin (STZ)-induced diabetic nephrotoxicity in Wistar rats. HFD-fed and low dose STZ (35 mg/kg, i.p)-induced diabetic rats were treated with EER (100 and 200 mg/kg/day) for 21 days while continuing on HFD. Preventive effects of EER were demonstrated by significant reduction
(p< 0.01) in body weight gain, fasting blood glucose, blood pressure, serum lactate dehydrogenase (LDH), creatinine, alkaline phosphatase (ALP), total cholesterol and triglyceride levels, while elevation in serum albumin and total protein levels. Insulin sensitizing effects were seen during oral glucose tolerance testing. Further, EER treatment significantly (p< 0.01) decreased the kidney thiobarbituric acid-reactive
substance (TBARS) levels, while increasing
the superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels in diabetic rats. Histological studies of kidney also supported the experimental findings. Taken together, our data suggest that EER attenuates renal injury in type 2
diabetic rats, possibly by improvement in glucose and lipid metabolism, enhancement of insulin sensitivity, blood pressure lowering, and inhibition of lipid peroxidation process
Microalgae and Its Use in Nutraceuticals and Food Supplements
Microalgae are a large diverse group of microorganisms comprising photoautotrophic protists and prokaryotic cyanobacteriaâalso called as blue-green algae. These microalgae form the source of the food chain for more than 70% of the worldâs biomass. It contains higher nutritional values, with rapid growth characteristics. Microalgae are autotrophic organisms and extensively desired for use in nutraceuticals and as supplement in diet. Many microalgal species are documented for health benefits, by strengthening immune system and by increasing the nutritional constitution of body. In this chapter the major economically important species like Spirulina, Chlorella, Haematococcus, and Aphanizomenon are described with reference to its importance as nutraceuticals and food
Design and operation of microchemical systems for multistep chemical syntheses
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2008.Includes bibliographical references (leaves 174-184).This thesis focused on advancing the microchemical field from single device based demonstrations to systems that can perform multi-step series and parallel synthesis. Few examples of micro-separators and micro-pumps suited for miniaturized lab-on-a-chip systems for organic syntheses exist, so the first half of this thesis developed systems for these micro-unit-operations, while the second half demonstrated multistep microchemical operations enabled by these systems. In-line continuous separation devices are developed that enabled removal of unreacted reagents/byproducts, making it possible to realize a series of reactions without leaving the microreactor environment. Differences in surface forces and preferential wettability characteristics of fluoropolymers are used for phase separation. Such microseparators are used to demonstrate 100% separation of two phase flows of hexane and water, toluene and water, dichloromethane and water, and hexane and methanol. Integrated liquid-liquid extraction devices are microfabricated that performed two -phase contacting by segmented flow, followed by separation - resulting in single stage extraction. Single stage extraction of N,N-dimethylformamide from dichloromethane to water, and from diethyl ether to water is demonstrated. The development of separators allows microreactors to be connected to microseparators to form microreactor networks enabling reactions and separations in succession. The starting reagents are loaded in syringes and syringe pumps push fluid through the train of microdevices. However, this pumping scheme is limited by pressure constraints at the pump drives as well as the microseparators. Therefore, there is a need to develop in-line pumps to sustain the microdevice network. Pressure-driven flow is employed for the operation of micropumps. An enclosure with the liquid is pressurized with helium gas, causing the liquid to flow. The dynamics of pressurizing and de-pressurizing an enclosure are modeled and confirmed by experiments. Active and passive control schemes to provide constant flowrate of the liquid are developed and implemented. Different schemes are developed to use the gas pressure to manipulate the flow path of liquids.(cont.) In one scheme, two enclosures are used together to perform as an in-line pump. The in-line pumps also acted as a buffer to prevent any disturbance propagation, and allowed the upstream and downstream to operate at different flowrates. The pump concept is demonstrated at two scales - 1) microfabricated silicon chips of 40 microliter volume and 2) using glass shell vials of 10000 microliter volume. These pumps are used along with two microseparators to demonstrate two-stage countercurrent and cross-flow liquid-liquid extraction of N,Ndimethylformamide from dichloromethane to water starting with 4.4 mole percent mixture. The in-line pumps also allowed recirculation with a constant flowrate that enabled long residence time reactions. As an example, peptide synthesis from amino acids, using the Merrifield technique is implemented. Specifically, the pentapeptide, Leuenkephalin is synthesized on different resins simultaneously as an example. A new design for the silicon microreactor for packed bed reactions is developed to enable larger catalyst loadings and offer manageable pressure drops across the packed bed even when the solid loading increased in volume during operation, as is the case with the peptide synthesis experiments. These microchips are also used to study "click chemistry" reactions to synthesize drug-candidate molecules. The packed bed microreactor experiments give higher conversions and better selectivities than batch experiments after the same amount of reaction time as the microreactor experiments provide increased relative catalyst concentration, and reduce side reactions that otherwise reduce selectivity. As an example of multi -step synthesis involving reactions and separations, the synthesis of carbamates starting from azoyl chloride and sodium azide, using the Curtius rearrangement of isocyanates is performed. This example also demonstrates parallel synthesis of analogous carbamates by introducing branching in the synthesis sequence after the isocyanate production to form microreactor networks. The second reaction involved heat decomposition of the organic azide, and performs faster when catalyzed using solid acid zeolite catalyst in a packed bed microreactor.(cont.) Continuous operation of the microdevice network for ~ 7-10 days at flowrates of 1-5 [mu]l/min show no change in performance. The microreactor based synthesis is run at higher temperatures than conventional batch scale reactions due to the inherent safety in microreactor based production. The multiple-carbamate-synthesis microreactor network consists of five microreactors and two separators. This demonstration is the first multi-step organic synthesis involving reactions and separations, and showcased the major contributions from this thesis. The development of micro-unit-operations in this thesis has advanced the microchemical field from single device based demonstrations to systems that can perform continuous-flow multi-step series and parallel chemical synthesis.by Hemantkumar Sahoo.Ph.D
New Paradigms in Medium-Term Operations and Planning of Power Systems in Deregulation
The operation of a large and complex electric power system requires meticulous and rigorous study and incessant planning. All the players involved, must plan ahead to account for the uncertainties that can affect the hour-to-hour, day-to-day, medium-term and long-term supply of electricity. Medium-term operations and planning provides the players with guidelines and strategies for short-term operating decisions vis-Ă -vis the market. Adequate planning helps the players to mitigate or be prepared for unforeseen circumstances encountered during scheduling of electricity generation at any stage. This thesis focuses on some aspects of the least explored medium-term operations and planning issues in power systems in the deregulated electricity market environment. The issues addressed in the thesis are diverse but inter-linked as medium-term problems, which have surfaced due to deregulation or are outcomes of unique thought-processes emerging from the restructuring phenomenon.
The thesis presents a novel approach to security coordinated maintenance scheduling in deregulation wherein the ISO does not generate a maintenance schedule by itself, but assesses the maintenance schedules from individual gencos by incorporating them in a medium-term security constrained production scheduling model, and verifying whether they result in unserved energy at one or more buses. Based on the information on bus-wise unserved energy, the ISO generates corrective signals for the genco(s), and directs them to alter their maintenance schedules in specific periods and re-submit. The proposed scheme exploits the concept of commons and domains to derive a novel factor to allocate the unserved energy at a bus to a set of generators responsible. The coordination scheme is based on individual gencoâs accountability to unserved energy at a bus.
Another important question addressed in the thesis is whether there is a need to consider customerâs locations in the power system when the utility provides service to them. In other words, whether the reliability of the load service provided by the utility varies across the system, from bus to bus, and if so, how are the Locational Marginal Prices (LMPs), which are determined from market auctions, affected by such variations. The thesis also answers the important question of how the LMPs can be differentiated by the Load Service Probability (LSP) at a particular location, so that it is fair to all customers. A new approach to determining the bus-wise LSP indices in power systems is proposed in the thesis. These LSP indices are arrived at by defining and computing bus-wise Loss of Load Probability (LOLP) indices. The discrepancy in LMPs with respect to the bus-wise LSP is then investigated and the bus-wise LSP indices are thereafter utilized to formulate a novel proposition for LSP-differentiated LMPs for electricity markets.
The thesis furthermore addresses the medium-term Transmission Reinforcement Planning (TRP) problem and proposes a practical approach to TRP by making use of standard design practices, engineering judgement, experience and thumb-rules to construct a Feasibility Set. The Feasibility Set helps in limiting the type and number of reinforcement options available to the transmission planner in selected existing corridors. Mathematical optimization procedure is then applied considering the Feasibility Set, to attain an optimal set of reinforcement decisions that are economical and meets the system demand in the medium-term, without overloading the transmission system. Two different solution approaches- the Decomposition Approach and the Unified Approach are proposed to solve the TRP optimization problem
An exploratory study of consumer demeanor towards financial investment
Investment is the employment of fund on assets with the aim of earning income or capital appreciation. Investments have become a basic necessity for everyone. In India there is a rapid growth in investment. This is why an understanding of consumer demeanor for financial investment is vital to the success of the business. The review paper covers the various financial avenues like equity/stocks, bank fixed deposits, kisan vikas patra, national savings certificate, life insurance, mutual fund and discusses the factors influencing investment decision process. The prime factors affecting the financial investment behavior are demographic factors and socio-economic factors. They can further be segregated as age, income, qualification, gender, social class, family income, tax benefits, safety of fund, brand perception, risk appetite, past performance, return on investment
- âŠ