Structural performance of alkali/acid-ultrasound modified Agave fibers during the melt mixing process with polyvinyl alcohol

This study aims to investigate changes in the structural properties of alkali/acid-ultrasound modified Agave fibers and their performance immersed on a polyvinyl alcohol (PVA) matrix with plasticizer during melt mixing processing. Structural analysis revealed that ultrasound enhances the effectiveness of the conventional alkaline/acid treatments to modify fibers since the simultaneous treatment increased the partial removal of lignocellulosic components, water molecules, and amorphous regions which improved their processability on a PVA matrix. Specific energy consumption values indicated that during melt mixing the modified fibers required more energy to expose the chains of cellulose fraction to function as an interaction site for PVA chains. Once the mixture was homogenized, the fiber-matrix interactions promoted high viscosity, friction, and mechanical stress in the chamber. Therefore, the modified fibers restricted the interaction between plasticizer and PVA in the obtained films, resulting in a highly structured, and reinforced network, increasing the storage modulus as dynamic mechanical analysis indicated. These findings highlight a feasible way to valorize Agave fibers and allow the understanding of the matrix-fiber interactions during melt mixing processing, useful to predict the structural and mechanical properties of the films.     

Influence of Polydimethylsiloxane on the Oxygen Concentration of Oils at Various Temperatures

The effect of temperature on the oil oxygen concentration, tested in both soybean and olive oils with no added polydimethylsiloxane (PDMS), showed that the oxygen concentration increased with temperature to approximately 100 °C. Above 100 °C, the oxygen concentration abruptly decreased. This change was attributed to the balance between the rates of oxygen uptake and consumption by oil oxidation, which favored oxygen consumption over uptake at temperatures above 100 °C. The addition of 100 ppb PDMS to soybean oil, enough to form a continuous layer over the surface of the oil, reduced the oxygen concentration when compared to a soybean oil control containing no added PDMS at temperatures ranging from 93 to 180 °C; thus suggesting an oxygen barrier effect of PDMS. The accumulation of PDMS at the air–oil interface in soybean oil held at 180 °C was determined by comparing the oil’s internal temperature and the apparent surface temperature. A decrease in the apparent surface temperature while the oil was held at a constant internal temperature was attributed to a change in the emissivity of the surface as a consequence of the accumulation of PDMS in the air–oil interface. The presence of PDMS at the air–oil interface was confirmed for 100 ppm of PDMS, a concentration greater than the concentration necessary to form a monolayer of PDMS on the oil surface.     

Molecular Partners of Escherichia coil Transcriptional Modulator AidB

The AidB protein is involved in the adaptive response to DNA alkylation damages in Escherichia coli. Functional proteomic experiments were designed to elucidate AidB biological functions in the presence and in the absence of methyl methanesulfonate as methylating agent. Several proteins were identified in both conditions and according to their reported biological activities, the inter-actors were grouped into three different functional categories： stress response, energetic metabolic pathways and nucleic acid metabolism. Particularly, the interaction between AidB and UvrA, a member of the UvrABCD nucleotide excision system, suggested a new interesting putative role for AidB.     

Parameter Sweep Workflows for Modelling Carbohydrate Recognition

Carbohydrate recognition is a phenomenon critical to a number of biological functions in humans. Understanding the dynamic behaviour of oligosaccharides should help in the discovery of the mechanisms which lead to specific and selective recognition of carbohydrates by proteins. Computer programs which can provide insight into such biological recognition processes have significant potential to contribute to biomedical research if the results of the simulation can prove consistent with the outcome of conventional wet laboratory experiments. In order to validate these simulation tools and support their wider uptake by the bio-scientist research community, high-level easy to use integrated environments are required to run massively parallel simulation workflows. This paper describes how the ProSim Science Gateway, based on the WS-PGRADE Grid portal, has been created to execute and visualise the results of complex parameter sweep workflows for modelling carbohydrate recognition.     

The language of demand/withdraw: Verbal and vocal expression in dyadic interactions.

Associations between vocally expressed emotional arousal, influence tactics, and demand/withdraw behavior were examined in a treatment-seeking sample of 130 seriously and stably distressed, married, heterosexual couples and in a community sample (N = 38) of 18 married heterosexual and 20 dating heterosexual couples. Fundamental frequency was used to measure emotional arousal, and computational linguistics were used to measure influence tactics. Higher levels of demand/withdraw behavior were associated with greater use of manipulative and controlling influence tactics, higher levels of emotional arousal, and less frequent use of cooperative and compromising influence tactics. Overall, demanders tended to express more arousal and to use more influence tactics than withdrawers. Both influence tactics and emotional arousal were uniquely associated with demand/withdraw behavior. Implications of results are discussed for refining theories of demand/withdraw interaction. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Parenting at risk: New perspectives, new approaches.

In this lead paper for this special section, we advance the perspective that new insights into parenting at risk can be gained by focusing on the dynamic emotional processes that occur during parent–child exchanges, with special emphasis on parental emotions as experienced and their regulation of emotion and underlying cognitions, as well as the role of developmentally rooted cognitions in shaping these associations. We discuss the very few but germinal studies that embody this perspective and introduce work in this section that examines emotion dynamics during parenting in real time. We believe this perspective will move us beyond static conceptualizations of parenting at risk, broadens our understanding of parenting as a process, and accelerates our ability to identify the essential targets of intervention when parenting is at risk. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Transforming shortcomings into opportunities: Can market incentives solve Lebanon's energy crisis?

Over the past decades Lebanon's energy sector has been largely ignored and this has led to high economic and environmental costs. The sector is characterized by electricity poverty, an expanding and mainly unregulated transport sector and a lack of energy savings spanning through all sectors of the economy. Recently, the Government of Lebanon has committed to increase the share of renewable energy to 10% of the total energy supply by 2013 and to 12% by the year 2020; it also aims at reducing energy consumption by 6% by the year 2013. This paper aims at contributing to the formulation of a more comprehensive energy strategy for Lebanon by analyzing the recent changes in policy direction and by recommending legal, regulatory and policy measures in order to transform current shortcomings into opportunities allowing the country to become a regional ‘success story’ in the deployment of renewable energy and energy efficiency.     

A longitudinal study of the social and academic competence of economically disadvantaged bilingual preschool children.

This longitudinal study was conducted to gain understanding of the social–emotional and academic development of economically disadvantaged bilingual preschool children. In Study 1, the authors combined cognitive, psychosocial, and cultural-linguistic factors to determine profiles of social competence as measured by peer play. A person-centered analysis of 207 Hispanic American preschoolers (ages 4 and 5 years) yielded 6 distinct profiles, 2 of which were socially competent and 1 of which was vulnerable. Findings revealed profile differences in social competence and a significant relationship between bilingualism and social–emotional development. In Study 2, the authors determined which profiles were associated with later academic achievement and growth of English proficiency. Findings indicated a significant relationship of early social–emotional development to later academic success and English acquisition, highlighting the role of bilingualism. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Breaking the mold: The impact of working in a gender-congruent versus gender-incongruent role on self-reported sources of stress, organizational commitment, and health in U.K. universities.

We present an analysis of archive data collected using the ASSET (Cartwright & Cooper, 2002) from a stratified sample of employees (N = 2,005) working in higher education institutions in the United Kingdom in 2003. We hypothesized that employees working in gender-incongruent roles would report higher levels of work-related stress, poorer health, and lower organizational commitment compared with those working in gender-congruent roles. Interpreted in accordance with the role strain hypotheses, we found that women working in gender-incongruent roles reported significantly higher (p > .01) levels of stress, higher levels of minor ill-health problems, and lower levels of perceived commitment from their organizations compared with all other employees. Conversely, men who worked in gender-incongruent roles often reported the lowest levels of stress. The implications of these findings are discussed with reference to women’s progression in U.K. higher education. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gatekeeping or gate slippage? A national survey of counseling educators in Australian undergraduate and postgraduate academic training programs.

Counseling educators fulfill a complex and demanding role as gatekeepers. The role serves a quality control function and involves ethical and educational responsibilities; it also interfaces with a confounding array of issues. This study was undertaken to establish how counseling educators view and experience the gatekeeping function, and to identify the mechanisms implemented by training programs to facilitate educators in the gatekeeping process. Educators from across Australia involved in counseling training at the bachelor's degree or higher award level were surveyed (n = 63, response rate = 34%). Findings suggested that educators are highly motivated by their sense of responsibility toward the counseling profession when assessing students. Nevertheless, their gatekeeping efforts are often compromised having been predominantly impeded by a lack of clear evidence of the problematic issues and leniency biases within their programs. In addition, gatekeeping efforts have not been generally supported by program initiatives, such as written policy and procedures, which are recognized to be facilitative of the gatekeeping process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)