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.     

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.     

Developing students' critical thinking skills through visual literacy in the New Secondary School Curriculum in Hong Kong

This paper argues that the planned introduction of visual literacy into the New Secondary School Curriculum can play a crucial role in enabling students to think critically and creatively in Hong Kong's highly visual landscape. As Hong Kong's educational system remains entrenched in long-established and conventional pedagogies, the primacy given to the written word is in sharp contrast with the pragmatic roles that visual images play in students' day-to-day life. Hong Kong is well-known for its extremely high level of Internet / broadband penetration and media saturation, yet visual literacy is still in a state of infancy in Hong Kong. Therefore, from a curricular standpoint, as Hong Kong society relies to a greater degree than ever before on visual communication strategies, it is vital that visual literacy be integrated as part of the new curriculum under the current educational reforms. As contemporary Hong Kong culture becomes increasingly dependent on the visual environment, developing visual literacy to enhance students' learning can be an important step in the future towards a more successful implementation and development of the New Secondary School Curriculum.     

A Critical Review on Clinical Application of Separation Techniques for Selective Recognition of Uracil and 5-Fluorouracil

The most important objectives that are frequently found in bio-analytical chemistry involve applying tools to relevant medical/biological problems and refining these applications. Developing a reliable sample preparation step, for the medical and biological fields is another primary objective in analytical chemistry, in order to extract and isolate the analytes of interest from complex biological matrices. Since, main inborn errors of metabolism (IEM) diagnosable through uracil analysis and the therapeutic monitoring of toxic 5-fluoruracil (an important anti-cancerous drug) in dihydropyrimidine dehydrogenase deficient patients, require an ultra-sensitive, reproducible, selective, and accurate analytical techniques for their measurements. Therefore, keeping in view, the diagnostic value of uracil and 5-fluoruracil measurements, this article refines several analytical techniques involved in selective recognition and quantification of uracil and 5-fluoruracil from biological and pharmaceutical samples. The prospective study revealed that implementation of molecularly imprinted polymer as a solid-phase material for sample preparation and preconcentration of uracil and 5-fluoruracil had proven to be effective as it could obviates problems related to tedious separation techniques, owing to protein binding and drastic interferences, from the complex matrices in real samples such as blood plasma, serum samples.     

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.     

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.     

The Privatization of the Internet's Backbone Network

Scholars have neglected the privatization of the Internet's backbone network, despite the obvious significance of the U.S. government turning control of a powerful new communication technology over to the private sector. This article analyzes the transition from a government-sponsored backbone network to multiple commercially owned backbone networks. The authors also analyze the implications of the privatization on the Internet's governance, competition, and performance.