Synthetic and biological studies on a cyclopolypeptide of plant origin

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.     

Integrated MSS effects: An empirical health care investigation

Since accurate decisions are required for effective management, much research has focused on information systems that support decision making. Recently, this research has engendered frameworks, such as the management support system (MSS), that are designed to provide comprehensive and integrated support for the decision making process. Few, if any, studies have empirically measured the effects of these frameworks on decision making. This article offers empirical evidence on MSS effectiveness. It overviews the decision making process, presents an MSS for supporting the process, and assesses the influences of the MSS on the process and outcomes of health care decision making. The paper also examines the implications of the analyses for information systems research and health care practice.     

Performance impact of research policy at the Chinese Academy of Sciences

We present evidence on productivity improvement experienced by the research institutes of the Chinese Academy of Sciences (CAS) after its implementation of the Knowledge Innovation Program (KIP). Using a balanced panel of data on R&D inputs and outputs of 59 research institutes in CAS, we analyze the productivity, technological and efficiency changes from 1997 to 2005. We document that the CAS research institutes have a productivity growth of 12.5% from 1998 to 2005, which can be further decomposed into 8.8% attributed to technological progress and 3.3% to efficiency improvement. Results of regional analysis show that institutes in Beijing and Shanghai, performed better than institutes in other regions during the same period.     

Measuring Student Attitude and Knowledge in Technology-Rich Biology Classrooms

The use of technology in schools is now ubiquitous, but the effectiveness on the learning environment has mixed results. This paper describes the development and validation of an instrument to measure students’ attitudes toward and knowledge of technology with the aim of investigating any differences based on gender after a course where the science department made use of technology as an integral part of teaching biology. In this study, conducted in one school in the state of New York, in the United States of America, the Students’ Attitudes Toward and Knowledge of Technology Questionnaire was administered to nearly 700 high school science students. A principal component and principal factor analysis resulted in new scales from the validation of the instrument that demonstrated high reliabilities. There were statistically significant gender differences in all the scales of the questionnaire in favor of males.     

Teaching Multistep Equations with Virtual Manipulatives to Secondary Students with Learning Disabilities

Students with learning disabilities often struggle with the academic demands presented in secondary mathematics curricula. To combat these students’ struggles, researchers have studied various pedagogical practices and classroom technologies for teaching standards covered in subjects such as algebra and geometry. However, as the role of computer‐ and tablet‐based technologies in education grows, some areas of study, such as the use of virtual manipulatives, lack exploration. This study sought to assess the benefits of virtual manipulatives to teach secondary students with a learning disability in mathematics how to solve multistep algebraic equations. A multiple baseline design across three participants demonstrated a functional relation between the use of a virtual manipulative balance and teaching students to acquire, maintain, and generalize the skill of solving multistep algebraic equations. Results provide new evidence demonstrating virtual manipulatives as a beneficial age‐appropriate technology to teach higher order mathematical concepts to secondary students with a learning disability.     

Chromatography an educational tool

The technique of chromatography is studied to bring forth the underlying concepts such as adsorption, partition, polarity/ non-polarity of a compound. The materials required are very simple such as chalk, starch, ink, etc. Once the concepts are understood, the technique can be easily extrapolated to analyze complex biological samples as well.     

The 2008 Presidential Campaign: Political Cynicism in the Age of Facebook,MySpace, and YouTube

Considerable research over the years has been devoted to ascertaining the impact of media use on political cynicism. The impact of the Internet has been difficult to assess because it is not a single monolithic medium. For example, the 2008 presidential campaign was the first presidential campaign in which popular social networking sites such as Facebook, MySpace, and YouTube were widely available to voters. Therefore, the campaign offered the first opportunity to explore the influence of these social media on political cynicism. In this study, we examined whether the use of such social media influenced political cynicism. We also considered the influence of user background characteristics (e.g., self-efficacy, locus of control, political orientation, demographics, and influence of family and friends), motives for using social media for political information, and users’ elaboration on political content. Several individual differences were stronger predictors of political cynicism than was social media use. In fact, social networking use was a negative predictor of political cynicism. Results supported uses and gratifications’ notions that the influence of social media on political cynicism is more attributable to user background and media-use differences than to sheer use of these popular sites.     

To have or to be? The interplay between knowledge structure and market identity in knowledge-based alliance formation

We explore how a firm’s knowledge structure characteristics and market identity—as reflected in its position in the industry value chain and market status—influence knowledge-based alliance (KBA) formation. We propose that a firm’s propensity to form KBAs is affected by the congruence (or misalignment) between its knowledge structure characteristics (i.e., knowledge depth and scope) and the role it plays in the industry, as demanded by its position in the value chain. We further argue that while a firm’s market status can amplify the positive effect of the congruence, thereby enhancing a firm’s proclivity to form KBAs, being prominent can also hurt a firm when it faces a misalignment between its knowledge structure characteristics and externally induced expectations related to its value chain position. We validate our arguments using panel data on 1051 firm-year observations for 197 firms patenting in the global fuel cell industry for the period 1999–2009. By developing a richer understanding of the relationship between a firm’s knowledge-based resources and KBA formation, we answer the call for a better understanding of how and when firms can leverage their internal knowledge configurations to improve their proclivity to form alliances.     

Innovation and firm growth in high-tech sectors: A quantile regression approach

We relate innovation to sales growth for incumbent firms in high-tech sectors. A firm, on average, experiences only modest growth and may grow for a number of reasons that may or may not be related to innovative activity. However, given that the returns to innovation are highly skewed and that growth rates distributions are heavy-tailed, it may be misleading to use regression techniques that focus on the ‘average effect for the average firm’. Using a quantile regression approach, we observe that innovation is of crucial importance for a handful of ‘superstar’ fast-growth firms.