Transition from traditional to ICT-enhanced learning environments in undergraduate chemistry courses

This paper describes a three-year study conducted among chemistry instructors (professors and teaching assistants) at a post-secondary institution. The goal was to explore the integration process of information and communication technologies (ICT) into traditional teaching. Four undergraduate chemistry courses incorporated a course website, an electronic forum, computerized visualizations, and Web-based projects, into their curriculum. The learning technologies were integrated to enhance inquiry-based learning, visualizations, and knowledge sharing. The current study investigated chemistry instructors’ perceptions toward ICT and their activities while practicing the newly introduced technologies. The findings showed that integrating new practices is a phase-dependent process that consists of promises as well as complexities. Four transition steps were found to characterize the integration of ICT-learning environments: non-active, support-dependant, partial-independant, and total-independant. Findings indicated that the transition from traditional to ICT-enhanced learning environments involves ambivalent feelings and dichotomy among instructors.     

Review of The dissociative mind.

Reviews the book, The dissociative mind by Elizabeth F. Howell (see record 2005-14945-000). In her book, The Dissociative Mind, Elizabeth Howell presents a complex and thorough overview of what she describes as a "sea change" in psychoanalytic theory. From her vantage point as both psychoanalyst and traumatologist, she demonstrates how, in the last 15-20 years, relational trauma and the resulting impact on the individual mind-namely the splits and fissures that comprise dissociation- have made their way back into psychoanalytic thinking. Howell's elaboration of the overwhelmed, traumatized mind is very useful in clients who present with problems in thinking or who have limited capacity to symbolize. However, detailed clinical material of how an analyst thinking of dissociated self states would work with such a client, what Bromberg termed the "relational bridge," would support her fundamental assertions more effectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The mental health of men with a psychiatric disorder or traumatic brain injury: Wives' labeling and husbands' perceived control.

Objective: To investigate the relations among wives' labeling of their husbands' psychiatric disorder or brain injury as an organic illness, the husbands' perceived control over their disabilities, and the husbands' mental health. Participants: 57 male clients of the Department of Rehabilitation, Israel's Ministry of Defence (26 with a psychiatric disorder and 31 with a traumatic brain injury) and their wives. Measures: Illness Labeling Questionnaire, the Perceived Control Over Illness Questionnaire, and the Mental Health Inventory. Results: Husbands' mental health was low but did not differ according to disability; wives' labeling of husbands' condition was negatively related to the husbands' mental health; husbands' perceived control was positively related to their mental health for both disabilities. Conclusion: Organic illness labels, even when adopted by the wives of the persons with the disability, seem to be negatively related to that person's mental health, whereas perceived control over a mental disorder or a brain injury seems to contribute positively to mental health, independently of how the disorder or injury is labeled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hierarchical time-based information release

Rapid distribution of newly released confidential information is often impeded by network traffic jams, especially when the confidential information is either crucial or highly prized. This is the case for stock market values, blind auction bidding amounts, many large corporations'strategic business plans, certain news agencies'timed publications, and some licensed software updates. Hierarchical time-based information release (HTIR) schemes enable the gradual distribution of encrypted confidential information to large, distributed, (potentially) hierarchically structured user communities, and the subsequent publication of corresponding short decryption keys, at a predetermined time, so that users can rapidly access the confidential information. This paper presents and analyzes the efficiency of a novel HTIR scheme. Deholo Nali holds a M.Sc. in mathematics and a Ph.D. in Computer Science from the University of Ottawa, Canada. In the past, he worked for two years as a software developer and pursued research in the design and analysis of identity-based cryptographic protocols. His research interests now include identity theft and graphical password authentication.     

Flow induced fibre alignment in Mycoprotein paste

The effects of extrusion and squeeze flow processing on the microstructure of Mycoprotein filamentous paste, a novel meat product alternative, are investigated. The flow induced effects are quantified in terms of fibre orientation measured by a technique of fluorescence microscopy and image analysis. Imaging of the original mycelia fibre paste showed that its microstructure is ‘isotropic’. Squeezing of the native paste does not result in any significant fibre rearrangement. This is attributed to the high fibre concentration and, thus, high level of fibre entanglement in the squeezed film, and slip at the wall. A semi-concentrated suspension of mycelia fibres in a golden syrup matrix, however, shows considerable structural rearrangement throughout. Extrusion of the native paste leads to a high degree of fibre alignment in the direction of flow with a high proportion of the fibre population (80–90%) being realigned. An Exponential-Uniform Mix distribution was successfully used to describe fibre orientation in both extrusion and squeeze flow. The results show the strong link between the microstructure of highly structured food products and the mode of processing used. They may also have important implications for the rheological testing of such structurally complex materials, as the rheological response of the material may well dependent on the way it is made to interact with the instrument.     

Effect of carrier fluid viscosity on retention time and resolution in gravitational field-flow fractionation

Gravitational field-flow fractionation (GrFFF) is a useful technique for fast separation of micrometer-sized particles. Different sized particles are carried at different velocities by a flow of fluid along an unobstructed thin channel, resulting in a size-based separation. They are confined to thin focused layers in the channel thickness where force due to gravity is exactly opposed by hydrodynamic lift forces (HLF). It has been reported that the HLF are a function of various parameters including the flow rate (or shear rate), the size of the particles, and the density and viscosity of the liquid. The dependence of HLF on these parameters offers a means of altering the equilibrium transverse positions of the particles in GrFFF, and hence their elution times. In this study, the effect of the viscosity of the carrier fluid on the elution behavior (retention, zone broadening, and resolution) of micrometer-sized particles in GrFFF was investigated using polystyrene (PS) latex beads as model particles. In order to change the carrier liquid viscosity without affecting its density, various amounts of (hydroxypropyl) methyl cellulose (HPMC) were added to the aqueous carrier liquid. It was found that particles migrate at faster rates as the carrier viscosity is increased, which confirms the dependence of HLF on viscosity. At the same time, particle size selectivity decreased but peak shape and symmetry for the more strongly retained particles improved. As a result, separation was improved in terms of both the separation time and resolution with increase of carrier viscosity. A theoretical model for plate height in GrFFF is also presented, and its predictions are compared to experimentally measured values.     

Peptide nanotube-modified electrodes for enzyme-biosensor applications

The fabrication and notably improved performance of composite electrodes based on modified self-assembled diphenylalanine peptide nanotubes is described. Peptide nanotubes were attached to gold electrodes, and we studied the resulting electrochemical behavior using cyclic voltammetry and chronoamperometry. The peptide nanotube-based electrodes demonstrated a direct and unmediated response to hydrogen peroxide and NADH at a potential of +0.4 V (vs SCE). This biosensor enables a sensitive determination of glucose by monitoring the hydrogen peroxide produced by an enzymatic reaction between the glucose oxidase attached to the peptide nanotubes and glucose. In addition, the marked electrocatalytic activity toward NADH enabled a sensitive detection of ethanol using ethanol dehydrogenase and NAD+. The peptide nanotube-based amperometric biosensor provides a potential new tool for sensitive biosensors and biomolecular diagnostics.     

Relation between the quantity, type and duration of alcohol drinking and the development of alcoholic liver cirrhosis

Patients with alcoholic liver cirrhosis in Dalmatian region are presented in this paper and their social and medical characteristics are reviewed. The alcohol drinking habits of 211 patients with established clinical-laboratory criteria of alcoholic liver cirrhosis were investigated. The obtained results have been compared with the results of the control group. The average age of the patients was 51.6 years. Males were more numerous (2/3 of all examinees), while the average duration of alcohol consumption was 25.4 years. Wine was the most frequently consumed beverage (about 90% of cases) and the average daily intake was 151 g of pure alcohol. The authors prove by mathematical model that the occurrence of liver cirrhosis increases exponentially with the increase of the amount of alcohol consumed. Relative risk of the development of alcoholic liver cirrhosis increases many fold with the increase of the amount of alcohol consumed.     

Efficient identity-based security schemes for ad hoc network routing protocols

Wireless ad hoc networks consist of nodes with no central administration and rely on the participating nodes to share network responsibilities. Such networks are more vulnerable to security attacks than conventional wireless networks. We propose two efficient security schemes for these networks that use pairwise symmetric keys computed non-interactively by the nodes which reduces communication overhead. We allow nodes to generate their broadcast keys for different groups and propose a collision-free method for computing such keys. We use identity-based keys that do not require certificates which simplifies key management. Our key escrow free scheme also uses identity-based keys but eliminates inherent key escrow in identity-based keys. Our system requires a minimum number of keys to be generated by the third party as compared to conventional pairwise schemes. We also propose an authenticated broadcast scheme based on symmetric keys and a corresponding signature scheme.     

The Lise Meitner-Minerva Center for Computational Quantum Chemistry: 18 Years of Israeli-German Collaboration

We tell the story of the Lise Meitner-Minerva Center, its establishment and activities, its members and their scientific activity, and its instrumental role in weaving intense relationships with the theoretical community in Germany, and in amalgamating the Israeli community of computational quantum chemistry into a national center that enjoys a high international reputation.