484 research outputs found
Healing effect of phenytoin on excisional wound in experimental albino rats
No full textBackground and Objective: A common side effect with phenytoin is gingival hyperplasia. This apparent stimulatory effect of phenytoin on connective tissue suggested the possibility for its use in wound healing. This study aims to evaluate the effect of 1% and 2% phenytoin ointment on the excisional wound healing process in experimental albino rats, in comparison to 5% betadine ointment. Materials and Methods: Albino rats of Wistar strain (150200 g) were divided randomly into four groups (n = 6). The animals were anesthetized with ether, shaved on the back, and the skin was disinfected using cotton and alcohol wipes. Excisional round, full-thickness skin wounds of diameter 15 mm were created in the paravertebral area, at 5 mm from the midline on the back of all the animals, using sterile disposable acuderm biopsy needle. The following medications were applied topically to the wound twice daily for a maximum of 20 days. Group A rats served as negative control (untreated). Group B rats were applied 5% betadine ointment (positive control). Group C and group D rats had 1% and 2% phenytoin powder applied on them, respectively. Wound healing was measured on days 0, 4, 8, 12, 16, and 20 of the experiment. Number of days taken for complete epithelization of wound was also noted. Statistical analysis was done using analysis of variance (ANOVA) followed by TukeyKramer test and P 0.05). Conclusion: 2% phenytoin may be considered as an important agent for wound healing, but its role in the healing of infected wound needs to be explored further
Genetic and Molecular Basis of Albinism in Indian Patients
No full textOculocutaneous albinism (OCA) is a heterogeneous group of autosomal recessive disorders characterized by the congenital hypopigmentation of ocular and cutaneous tissues associated with some developmental abnormalities of the eye. Mutations in genes that directly or indirectly regulate the multistep process of melanin biosynthesis are the basis of this disease. OCA is reported as one of the four major causes of childhood blindness in India; carrier detection followed by genetic counseling is the only way to contain the disease. The study presented in this dissertation is mainly focused on the understanding of the molecular pathogenesis of OCA in Indian patients recruited mainly from eastern and southern regions of India.
The tyrosinase gene (TYR) encodes the rate-limiting enzyme of the melanin biosynthetic pathway, and on mutation causes OCA type 1 (OCA1). For my dissertation, I used TYR as the first candidate gene to study OCA. In an attempt to investigate the genetic lesions leading to OCA in the Indian population, 36 unrelated OCA pedigrees and 4 sporadic patients were subjected to cosegregation analysis and mutation screening. The mutation screening results of TYR suggested that the gene contributes to causation of the disease in 47.5% (19/40) of the OCA1 cases. Prevalence of defects in this gene in Indian population is primarily due to founder mutations and about 70% of the unaffected sibs of the OCA1 affected families were found to be carriers for TYR mutations.
Among the nucleotide variants, unlike in/del and nonsense mutations, nonsynonymous (i.e. missense) changes could exert a very wide range of its effect on the translated protein – that is, from being significantly damaging to completely innocuous towards biological activity. Therefore, to evaluate functional implication of the missense variants by functional assays I selected the following variants: (a) six missense changes that we found in Indian OCA1 patients, (b) three other reported missense mutations, and (c) two reported cSNPs. Eight of the nine missense mutations were observed to lack both tyrosine hydroxylase and DOPA-oxidase activities; and one variant (R299S) retained minimal (14.61) tyrosine hydroxylase activity with respect to the WT protein. One of the cSNPs (I222T) was also found to be devoid of any enzymatic activity while the other (S192Y) was found to code for a hypomorphic variant. All of the variants excepting S192Y were subsequently found to be retained in the Endoplasmic reticulum.
We also studied the role of other classical OCA genes viz. OCA2 (causal for OCA type 2), SLC45A2 (causal for OCA type 4) and TYRP1 (causes OCA type 3) as well as SLC24A5, a gene newly implicated towards melanin deficiency, in the tyrosinase positive OCA patients – that is where we could not find TYR mutations. Cosegreggation analysis followed by mutation screening revealed the following contribution of these four genes in causation of OCA: OCA2 – 12.5%, SLC45A2 – 7.5%, TYRP1 – 0% and SLC24A5 – 0%.
We also studied single nucleotide polymorphisms (SNPs) in TYR, OCA2 and SLC45A2 in a large number of Indians belonging to various ethnic groups from across entire nation through a collaborative effort with Indian Genome Variation Consortium. The data can be used to evaluate utility of these variants as markers for these loci and future study on relative contribution of these genes in skin color variation in different population groups
Pricing Derivatives: The Financial Concepts Underlying the Mathematics of Pricing Derivatives
No full textA fresh, fundamentals-based approach for accurate derivative pricing
Pricing Derivatives presents a specialized approach to accurately pricing derivatives by stressing the conceptual foundations underlying the mathematics. Noted mathematics professor and investing consultant Ambar Sengupta provides a sound understanding of the essential topics of derivative pricing and outlines methodologies for arriving at exact pricing formulas based on the fundamental relationship between price and probability.
Short, to-the-point chapters present original ideas and approaches for pricing derivative products, supplying professional money managers and institutional investors with the foundation they need to: Integrate both the theoretical and mathematical foundations of pricing derivatives Establish optimal prices in terms of the no-arbitrage principle Derive model-independent pricing formulas for options, futures, forwards, and other key derivatives
Experience has shown that derivative traders must focus on conceptual, as opposed to trading, issues if they are to improve trading accuracy and profitability. Pricing Derivatives presents conceptually sound approaches for pricing derivatives and shows how to use them to compute specific pricing formulas.
Pricing Derivatives unveils a fundamentally clear-cut approach to accurate derivative pricing. Based upon author Ambar Sengupta\u27s years of consulting experience working with derivatives traders to hone their trading performance, it steers around the mechanics of popular financial models to focus on the conceptual foundations and underlying mathematics of pricing derivatives as well as other financial instruments.
Exploring the relationshipbetween price and probability, Pricing Derivatives demonstrates methods for determining model-independent pricing formulas and applying them to specific market models for more distinct and applicable pricing formulas.https://repository.lsu.edu/facultybooks/1593/thumbnail.jp
Assessment of dopaminergic neuron degeneration in a C. elegans model of Parkinson's disease
No full textTransgenic Caenorhabditis elegans that expresses the full-length wild-type human α-synuclein in dopaminergic neurons provides a well-established Parkinson's disease (PD) nematode model. Here, we present a detailed protocol to monitor and dissect the molecular underpinnings of age-associated neurodegeneration using this PD nematode model. This protocol includes preparation of nematode growth media and bacterial food sources, as well as procedures for nematode growth, synchronization, and treatment. We then describe procedures to assess dopaminergic neuronal death in vivo using fluorescence imaging. For complete details on the use and execution of this protocol, please refer to SenGupta et al. (2021). © 2022 The Author(s
Financial Management of Globalization of Developing Countries
No full texthuman development, economic growth, globalization, inequality, poverty
Synchronous and Asynchronous Auction Models for Dynamic Spectrum Access
No full textRecently, there is an urge to allocate chunks of the spectrum to the wireless service providers on a more dynamic basis rather than the current practice of static allocation. This shift in paradigm is a result of many studies that indicate the improper utilization of the spectrum by the service providers due to the static spectrum assignment. Also, the use of the spectrum has been found to be space and time invariant. In this paper, we investigate the dynamic spectrum allocation policy for optimal use of the spectrum band. We propose a dynamic spectrum assignment strategy based on auction theory that captures the conflict of interest between wireless service providers and spectrum owner, both of whom try to maximize their respective benefits. We compare two different allocation strategies - synchronous and asynchronous. It is demonstrated that synchronous strategy outperforms the asynchronous strategy. Through simulation results, we show how the optimal usage of spectrum band is achieved along with the maximized revenue for spectrum owner and higher probability of winning spectrum for the service providers. © Springer-Verlag Berlin Heidelberg 2006
Distributed Power Control in Sensor Networks: A Game Theoretic Approach
No full textIn wireless sensor networks, where energy of the sensor nodes are finite, power control is an important issue to consider. In this paper, we present a game-theoretic approach to solve the power control problem in CDMA based distributed sensor networks. A non-cooperative game is formulated and the existence of Nash equilibrium is studied for the sensor nodes operating under incomplete information. With the help of this equilibrium, we devise a distributed algorithm for optimal power control and prove that the system is power stable if the nodes comply with certain transmission thresholds. We show that even in the distributed non-cooperative scenario, it is in the best interest of the nodes to remain within these thresholds. The power level at which a node should transmit, to maximize its utility, is also evaluated. Numerical results prove that with the proposed algorithm, the sensor nodes are able to achieve best possible payoff by consuming less power, resulting in extended network lifetime. © Springer-Verlag Berlin Heidelberg 2004
Sequential and concurrent auction mechanisms for dynamic spectrum access
No full textAbstract—With the ever growing demands for spectrum, au-thorities (e.g., FCC in United States) are defining ways that allow reallocation of spectrum bands that are under-utilized. In this regard, FCC made provisions to open under-utilized bands for both licensed and unlicensed services. A new paradigm called dynamic spectrum access (DSA) is being investigated that would allow wireless service providers (WSPs) to dynamically seek more spectrum when and where they need without interfering with the primary users. Currently, there is little understanding on how such a dynamic allocation of spectrum will operate so as to make the system feasible under economic terms. In this paper, we analyze the dynamic spectrum allocation process from an auction theoretic point of view where n WSPs (bidders) compete to acquire necessary spectrum band from a pool of m (n> m) spectrum chunks. For the purpose of self-coexistence, each of the WSPs is granted at most one chunk of spectrum to minimize interference among themselves and with licensed services. In this regard, we investigate both sequential and concurrent auction mechanisms to find WSPs ’ optimal price bid and compare both the auction mechanisms in terms of revenue generated. We show that sequential auction is a better mechanism for DSA. I
Detailed analytical and experimental investigations on voltage source inverter fed Induction Heating prototype
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