Modulation of DMBA- induced biochemical and histopathological changes by Syzygium cumini seed extract during skin carcinogenesis

Aim & Method: The current study was designed to elucidate the protective effect of Syzygium cumini seed extract (SCE) on skin carcinogenesis induced by a single topical application of 7,12-dimethylbenz(a)anthracene (100 μg/100 μl of acetone) and 2 weeks later promoted by repeated application of croton oil (1% in acetone/three times a week) till the end of the experiment (16 weeks). Result: Oral administration of SCE at a dose of 125 mg/kg b.wt./day for 15 days at the peri-initiational stage (i.e., 7 days before & 7 days after DMBA application) and for 14 weeks at the promotional stage (i.e., from the time of croton oil application), revealed a significant reduction in lipid peroxidation (p<0.05-0.001) along with an elevation in the activities of enzymatic antioxidants (superoxide dismutase, p<0.05-0.001 & catalase, p<0.05-0.001), non-enzymatic antioxidant (reduced glutathione, p<0.05-0.01 & vitamin-C, p<0.01-0.001) and total proteins levels (p<0.01-0.001) when compared to the carcinogen treated control animals. Histopathological study revealed that dyskeratosis of the epidermis, deposition of keratinous pearl and epidermal hyperplasia in skin tumors of DMBA treated control and the same were found to be of lesser degree in both the SCE treated experimental animals. Conclusions: These results demonstrate that SCE ameliorate the DMBA/croton oil induced adverse biochemical and histopathological alterations during skin carcinogenesis in mice

Thylakoid Protein Targeting/Insertion by a Signal Recognition Particle in Chloroplasts

Protein targeting is a fundamental cellular process that directs proteins from their site of synthesis to the site where they function. The signal recognition particle (SRP) dependent targeting pathway is conserved in both eukaryotes and prokaryotes where it co-translationally targets polypeptide chains emerging from ribosomes to the endoplasmic reticulum (eukaryotes) or cytoplasmic membrane (prokaryotes). A structurally unique form of SRP is found in chloroplasts where it functions to post-translationally bind and target a subset of integral thylakoid membrane proteins, the light harvesting chlorophyll binding proteins (LHCPs). Mature LHCPs bind chlorophyll a/b and function in photosynthetic light capture. Like many other chloroplast proteins, LHCPs are nuclear encoded and synthesized in the cytosol. Following their import into the chloroplast stroma, LHCPs associate with chloroplast SRP (cpSRP), which maintains LHCP solubility and initiates targeting of LHCP to the thylakoid membrane via an cpSRP receptor (cpFtsY) at the thylakoid membrane. Both cpSRP and cpFtsY are GTPases and associate at the thylakoid by a mechanism that requires GTP binding by both proteins. Subsequent insertion of LHCP into the lipid bilayer is mediated by a protein insertase Albino3 (Alb-3), which binds cpSRP to stimulate LHCP release from cpSRP and GTP hydrolysis by both cpSRP and its receptor. Work here has focused on studies to understand mechanistic details of the cpSRP targeting pathway and better understand the timing of targeting events at the membrane. The results provide support for a structure-based chronology of protein interactions between LHCP targeting substrates, cpSRP, cpFtsY, and Alb-3. They also demonstrate that GTP hydrolysis by cpSRP and its receptor at the membrane is not necessary for LHCP insertion by Alb-3, but serves to maintain an available pool of Alb-3 insertase at the membrane by stimulating the exit of cpSRP targeting components following release of LHCP from cpSRP to Alb-3

Comparative Analysis of Various Decision Tree Classification Algorithms using WEKA

Classification is a technique to construct a function or set of functions to predict the class of instances whose class label is not known. Discovered knowledge is usually presented in the form of high level, easy to understand classification rules. There is various classification techniques used to classify the data, one of which is decision tree algorithms. This paper presents a comparative analysis of various decision tree based classification algorithms. In experiments, the effectiveness of algorithms is evaluated by comparing the results on 5 datasets from the UCI and KEEL repository. DOI: 10.17762/ijritcc2321-8169.15025

The Impact of Asymmetric Information: Applications in Enterpreneurship and Finance

This dissertation consists of three essays examining the impact of information asymmetries in context of entrepreneurship and finance. Chapter 2, coauthored with Silvana Krasteva and Liad Wagman, focuses on the asymmetries between a firm and its (researcher) employee and studies the problem faced by a (researcher) employee when choosing whether to pursue an innovative idea as part of his employment at a firm or to form a start-up. An idea by its stand-alone value and by the degree of (positive or negative) externality that it may impose on the employing firm’s existing profits if brought to market. The employee has private information about the innovation and his ability to independently develop it. Internal exploration, while allowing the employee to take advantage of any exploration support offered by the firm, reduces the employee’s claim over his idea. We find that external exploration takes place for ideas weakly related to the firm’s existing offerings, with other ideas being explored internally. We show that if the firm increases its support for exploration, it can induce the internal research of a wider range of ideas; however, by doing so, the firm also increases the likelihood of employees departing to pursue independent ventures at a later stage of development. Chapter 3 analyzes the benefits of reducing information asymmetry in the credit markets. In their attempt to make more informed decisions, lenders of- ten use a variety of information contained in a borrower ’s credit report. We find that if a borrower expects his future lenders to base their decisions not only on his repayment history but also on other factors like his income, length of history, etc., then his incentives to repay his present loan are weakened. In this case, he is more likely to strategically default on his loan especially for very high levels of interest rates. However, use of this extra information assists the lender in expeditious screening of the borrowers. Based on our results, we recommend that, in order to minimize defaults, more repayment history based products should be offered by the lenders. Evidence supporting the validity of this recommendation is provided in Chapter 4, coauthored with Vijetha Koppa. Using data from Prosper.com, we analyze the effect of reporting repayment histories to an additional credit bureau on borrowers’ default rates and lenders’ internal rates of return. A differences- in-differences comparison between high risk and low risk borrowers reveals that for high risk borrowers, the default rates were 9 to 11 percentage points greater and the internal rates of return were 13 percentage points lower in the pre-change period

Gender differences in a Drosophila transcriptomic model of chronic pentylenetetrazole induced behavioral deficit

A male Drosophila model of locomotor deficit induced by chronic pentylenetetrazole (PTZ), a proconvulsant used to model epileptogenesis in rodents, has recently been described. Antiepileptic drugs (AEDs) ameliorate development of this behavioral abnormality. Time-series of microarray profiling of heads of male flies treated with PTZ has shown epileptogenesis-like transcriptomic perturbation in the fly model. Gender differences are known to exist in neurological and psychiatric conditions including epileptogenesis. We describe here the effects of chronic PTZ in Drosophila females, and compare the results with the male model. As in males, chronic PTZ was found found to cause a decreased climbing speed in females. In males, overrepresentation of Wnt, MAPK, TGF-beta, JAK-STAT, Cell communication, and Dorso-Ventral axis formation pathways in downregulated genes was previously described. Of these, female genes showed enrichment only for Dorso-Ventral axis formation. Most significant, ribosomal pathway was uniquely overrepresented in genes downregulated in females. Gender differences thus exist in the Drosophila model. Gender neutral, Dorso-Ventral axis formation may be considered as the candidate causal pathway in chronic pentylenetetrazole induced behavioral deficit. Prior evidence of developmental mechanisms in epileptogenesis underscores the usefulness of fly model. Gender specific pathways may provide a lead for understanding brain dimorphism in neuropsychiatric disorders