Passive rational fitting of a network transfer function from its real part

A methodology is presented for the rational function approximation of a passive network function from sampled values of its real part over the bandwidth of interest. The accuracy and validity of the proposed methodology are demonstrated through its application to the fitting of several broadband, multiport transfer functions. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

Researching pedagogy: a sociocultural agenda

Pedagogy is currently receiving attention from producers of education policy in England. It is, however, a version of pedagogy that remains located in a history of schooling as social control, of curricular knowledge as a commodity to be transmitted and of teachers as paraprofessionals. Those who resist recent attempts to shape pedagogy, and attempt to enhance both pedagogy and professionalism in order to prepare learners and teachers for informed participation in the new knowledge economy, are constrained by the impoverished understandings of pedagogy available in the United Kingdom. The author argues that understandings of pedagogy that are grounded in the hermeneutic psychology offered by Vygotskian theory can enhance teachers' professionalism and inform a pedagogy for the new knowledge age, 'Vygotsky is concerned to study how people, through the use of their own social activities, by changing their own conditions of existence can change themselves' (Shotter, 1993, p. 111).     

Change experienced during group therapy by female survivors of childhood sexual abuse.

Change during a 20-week group therapy program was researched for 40 women who were survivors of childhood sexual abuse. Results indicated that the women who participated in group therapy, compared with a quasi-experimental control group, decreased significantly on measures of depression, social maladjustment, self-blame, and posttraumatic stress responses, with no significant increases in anger. Scores on the main variables remained stable during assessment and follow-up periods for the women who participated in group therapy. In addition, there were no significantly different patterns of change based on either sexual abuse variables (number of perpetrators, sexual abuse by a father figure, nature of sexual abuse, and duration) or participation in concurrent individual therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sugarcane spirit extracts of oak and Brazilian woods: antioxidant capacity and activity

Sugarcane spirit extracts of six different Brazilian woods for potential use in manufacturing aging casks were compared with similar extracts of five oak samples from different geographic origin and heat treatment regarding: (1) content of phenolics and copper; (2) radical reducing capacity and reactivity toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·); and (3) effect on the rate of oxygen depletion rate in a peroxidating lipid model system. Total phenolic contents of the Brazilian wood extracts ranged from 0.65 (canela-sassafrás) to 6.4 (jatobá) mmol_GAE L⁻¹ and from 1.39 to 2.87 mmol_GAE L⁻¹ for oak extracts. Flavonoids ranged from 1.54 × 10⁻⁴ (ipê) to 6.5 × 10⁻² (oak) mmol_rutin L⁻¹, and tannins from below the detection limit to 0.22 (jatobá) mmol_{tannic acid} L⁻¹. Correlation was observed for the antioxidant capacity versus phenolics/flavonoids/tannins content, where oak extracts exhibit the highest radical scavenging capacity compared to Brazilian woods. Rate constant for radical scavenging by the extracts ranged from 4.9 × 10³ M⁻¹ s⁻¹ (canela-sassafrás) to 9.7 × 10⁴ M⁻¹ s⁻¹ (oak). The oxygen consumption index showed the Brazilian woods amendoim and jatobá to be more efficient inhibitors than the oak extracts for lipid autoxidation initiated by metmyoglobin, despite that the oak extracts seem to be more efficient to scavenge DPPH·. No simple correlation with phenolics or copper content could be established, and a prooxidative tendency was observed for the extracts of canela-sassafrás, castanheira, and louro-canela.     

Urinary Bladder Cancer Susceptibility Markers. What Do We Know about Functional Mechanisms?

Genome-wide association studies (GWAS) have been successful in the identification of the several urinary bladder cancer (UBC) susceptibility loci, pointing towards novel genes involved in tumor development. Despite that, functional characterization of the identified variants remains challenging, as they mostly map to poorly understood, non-coding regions. Recently, two of the UBC risk variants (PSCA and UGT1A) were confirmed to have functional consequences. They were shown to modify bladder cancer risk by influencing gene expression in an allele-specific manner. Although the role of the other UBC risk variants is unknown, it can be hypothesized—based on studies from different cancer types—that they influence cancer susceptibility by alterations in regulatory networks. The insight into UBC heritability gained through GWAS and further functional studies can impact on cancer prevention and screening, as well as on the development of new biomarkers and future personalized therapies.     

Revealing the Roles of Subdomains in the Catalytic Behavior of Lipases/Acyltransferases Homologous to CpLIP2 through Rational Design of Chimeric Enzymes

The lipases/acyltransferases homologous to CpLIP2 of Candida parapsilosis efficiently catalyze acyltransfer reactions in lipid/water media with high water activity (a_W>0.9). Two new enzymes of this family, CduLAc from Candida dubliniensis and CalLAc8 from Candida albicans, were characterized. Despite 82 % sequence identity, the two enzymes have significant differences in their catalytic behaviors. In order to understand the roles played by the different subdomains of these proteins (main core, cap and C‐terminal flap), chimeric enzymes were designed by rational exchange of cap and C‐terminal flap, between CduLAc and CalLAc8. The results show that the cap region plays a significant role in substrate specificity; the main core was found to be the most important part of the protein for acyltransfer ability. Similar exchanges were made with CAL‐A from Candida antarctica, but only the C‐terminal exchange was successful. Yet, the role of this domain was not clearly elucidated, other than that it is essential for activity.     

Learning by Failing (and Fixing)

Unfortunately, students can graduate with a software engineering degree without learning anything about building secure systems. However, for the past two years at the Norwegian University of Science and Technology, a software security course has been giving students the theoretical foundation and practical experience necessary to start comprehending software security issues.     

Memory for Contextual Details: Effects of Emotion and Aging.

When individuals are confronted with a complex visual scene that includes some emotional element, memory for the emotional component often is enhanced, whereas memory for peripheral (nonemotional) details is reduced. The present study examined the effects of age and encoding instructions on this effect. With incidental encoding instructions, young and older adults showed this pattern of results, indicating that both groups focused attention on the emotional aspects of the scene. With intentional encoding instructions, young adults no longer showed the effect: They were just as likely to remember peripheral details of negative images as of neutral images. The older adults, in contrast, did not overcome the attentional bias: They continued to show reduced memory for the peripheral elements of the emotional compared with the neutral scenes, even with the intentional encoding instructions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)