The 2010 chemistry nobel prize: Pd(0)-catalyzed organic synthesis

The 2010 Nobel Prize in Chemistry was awarded to three scientists, R F Heck, E-I Negishi and A Suzuki, for their work on “Palladium — Catalyzed Cross Couplings in Organic Synthesis”. It pertains to research done over a period of four decades. The synthetic procedures embodied in their work enable construction of C-C bond selectively between complex molecules as in simple ones at desired positions without disturbing any functional groups at other parts of the reacting molecules. The work finds wide applications in the synthesis of pharmaceuticals, agricultural chemicals, and molecules for electronics and other applications. It would not have been possible to synthesize some of the complex natural products or synthetic compounds without using these coupling reactions in one ormore steps.     

Assessment of Hematological Parameters in Pulmonary Tuberculosis Patients

The aim of the study was the assessment of hematological parameters in pulmonary tuberculosis patients. Forty patients diagnosed with tuberculosis were recruited from the Institute of Thoracic Medicine on the basis of history, clinical examination, chest radiography, sputum examination and related laboratory parameters and were compared with age and sex matched healthy volunteers (n = 40). Hematological parameters and CRP in tuberculosis patients were determined. The mean values for serum hemoglobin level, RBC count and platelet count in PTB was found to be less (p < 0.001). Erythrocyte sedimentation rate (ESR), plasma C-reactive protein, WBC count in PTB subjects was increased (p < 0.001 for ESR & CRP, p < 0.05 for WBCs) and all were statistically significant. This study demonstrated that serum hemoglobin level, RBC count and platelet count was decreased in tuberculosis patients whereas ESR, CRP and WBC count was increased when compared with healthy controls.     

Peter Debye and electrochemistry

Debye won the 1936 Nobel Prize in Chemistry for his contributions to molecular structure, dipole moment relationship and for diffraction of X-rays and electrons. Electrochemists, however, remember him for the Debye-Hückel limiting law that describes the behavior of strong electrolytes. In explaining the non-ideal behavior of strong electrolytes, his mathematical treatment assumes that each ion is surrounded by an ionic cloud of oppositely charged ions, which retards the movement of ions in the medium. The theory not only provides a method for calculation of activity coefficients, but has also helped, among other things, in our understanding of diffusion in ionic media, change in the rate of ionic reactions upon addition of salts, and biochemical reactions.     

Low cost demonstration experiment Lorentz force: Change in path of charged particles in magnetic field

The path of charged particles is affected when they enter a magnetic field. This change of path largely depends on the angle between the applied magnetic field and the direction of motion of the charged particle (and its velocity) entering the magnetic field. This is demonstrated by means of a simple, low-cost experiment. A high voltage is used to ionize the air between a spark gap. The flow of charged particles between the spark gap is altered by applying a magnetic field from a rare earth permanent magnet having surface magnetic field induction of 0.12 T.     

Purification and characterization of chymotrypsin-like enzyme from rat plasma

A chymotrypsin-like enzyme was purified from rat plasma, involving ammonium sulfate fractionation and chromatographgy on CM-sephadex and red sepharose. The purified enzyme effectively hydrolysed the ester substrates for chymotrypsin (N-acetyl L-tyrosine ethyl ester and N-acetyl L-tryptophan ethyl ester). The Km values for the two substrates were 2.2×10^?3M and 9.0×10^?3M respectively. The hydrolytic activity of the enzyme was inhibited by phenylmethyl sulfonyl fluoride and tosylphenylalanine chloromethylketone, suggesting the presence of serine and histidine at the active centre. The enzyme exhibited anionic nature and possessed a high molecular weight (MW 71,000) as observed by gel exclusion chromatography on Sephadex G-200. The enzyme was stable upon exposure to pH 7.0–9.0, but was inactivated upon heat treatment at 60°C for 5 min.     

A metric measure for direct comparison of competing models in covariance structure analysis

Comparing the fit of alternative models has become a standard procedure for analyzing covariance structure analysis. Comparison of alternative models is typically accomplished by examining the fit of each model to sample data. It is argued that rather than using this indirect approach, one should do direct comparisons of the similarities and differences among competing models. It is shown that among the existing good‐ness‐of‐fit indexes, the root mean square residual (RMSR) is the only one that can be used for this purpose. However, the RMSR fails to satisfy some important statistical desiderata. Rao's Distance (RD), an alternate measure, is shown to overcome this limitation of RMSR. The preference for RD over RMSR for model comparisons is illustrated through a detailed analysis of a particular sample of multitrait‐multimethod data. A simulation study conducted to empirically investigate the sampling behavior of RD reveals that the true orderings of intermodel proximities are recovered (on average) with a fair degree of accuracy.     

Bridging East and West educational divides in Singapore

In Asia, we are witnessing an era where the pendulum of power is swaying towards the East with the rising economic strength of China and India. Singapore is at the ‘crossroads’ between the East and West of these most populous nations on earth. Although Singapore may appear the most Westernised country in Asia, she is nevertheless a multicultural Asian society. Having the most open economy in the world, Singapore is affected by the process of globalisation. This takes on an added dimension and speed as nations compete for talent and find ways to internationalise and transform their education for sustainable competitive advantage. Singapore's education system, regarded as one of the best performing in the world, offers a unique opportunity to explore the issues where East and West culture, values and systems meet. This article discusses and highlights what happens when East and West converge. In particular, the discussion will focus on the themes of East and West schism, globalisation and Singapore's aspirations to be a global hub, rankings and branding in education, and the use of the English language.     

Legitimating status: perceptions of meritocracy and inequality among undergraduates at an elite British university

Given the frequent critiques of elite universities for admitting low numbers of state school graduates and, more recently, British Afro‐Caribbean students, how do students attending those universities make meaning of the admissions process? Through an analysis of 46 one‐on‐one in‐depth interviews with undergraduates attending Oxford University, we show that students believe in the fairness of the admissions process, while lamenting the lack of opportunities for educational advancement faced by some disadvantaged youth in British society. Despite their understanding that many British youth do not have access to educational experiences that make Oxbridge an attainable goal, most students do not support changes to make access more equitable across class or racial/ethnic lines. This perspective, which legitimates the status students gain through matriculation at an elite university, supports the maintenance of unequal access to an Oxford education despite the advantages that education is known to confer to graduates. The findings demonstrate elites acknowledging the disadvantages of particular groups in society without acknowledging their own advantages in the same system. They do so by recognizing two elements of merit: (1) intelligence, which most students assumed led to their own admission; and (2) cultivation of that intelligence, which requires elite secondary schools and which most students see as disadvantaging particular groups in society. In the paper we highlight differences in meaning‐making between graduates of grammar, comprehensive and private schools.     

Expanding the Nomological Network of Work Avoidance: Antecedents and Consequences Across Contexts

Abstract

Work avoidance, or the goal to reduce effort in an achievement context, is related to disengagement and may offer insight into disengaged students and employees. To shed light on this issue, we investigated the antecedents of work avoidance in academic and work contexts to distinguish it from mastery, performance-approach, and performance-avoidance goals. Two samples of employed college students (N?=?207, N?=?233) completed questionnaires about their jobs and in one sample about their introductory psychology class. Across both contexts, proposed antecedents of alienation, low need for achievement, and perceiving one’s competence needs as not being met predicted work avoidance. Work avoidance also accounted for additional variance when combined with achievement goals to predict citizenship behaviors, perceiving work/classwork as meaningless and wanting to leave/quit.     

Dynamic and spatial representation of web movements and navigational patterns through the use of navigational paths as data

Solving real-world problems is an effective learning activity that promotes meaningful learning in formal educational settings. Problems can be classified as being either well structured or ill structured. Internet information search approaches have an influential role to play in the successful performance of problem solving. A better understanding of how students differentially model information search strategies and movements in tackling well- and ill-structured problems is essential for creating engaging problem-solving environments for students. Static measures, such as the number of accessed nodes or links, or the number of times particular web browser function buttons are clicked, are limited in their ability to analyze attributes of information search patterns. A more dynamic and spatial representation of web movements and navigational patterns can be realized through the use of navigational paths as data. The two path-specific structural metrics that can be used to assess network-based navigational paths in relation to the structuredness of the problem-solving task are compactness and stratum. These metrics are, respectively, the indicators of the connectedness and linearity of network-based structures defining students’ online navigational visitations during the problem-solving sessions. This study explored the relevance and utility of these two metrics in analyzing the navigational movements of learners in seeking out electronic information to accomplish successful problem solving. The outcome findings of this study show that well- and ill-structured problems demand different cognitive and information seeking navigational approaches. The differing values of the two path metrics in analyzing the search movements organized by students in attending to well- and ill-structured problems were a direct result of the contrasting patterns of navigational path movements. The search patterns associated with well-structured problem solving tended to be more linear and less connected, whereas those related to ill-structured problem solving were more distributed and inter-connected.