How heterogeneous are adolescents’ preferences for natural and semi-natural riverscapes as recreational settings?

Recent research has indicated that the younger generations may be disconnected from nature and even show some dislike for natural conditions. This study addressed adolescents’ preferences for riverscapes with varying fluvial dynamics as recreational settings. A stated choice survey with digitally calibrated river scenarios asked Austrian pupils (N = 281) about their preferences for several physical and social characteristics of a floodplain landscape. Pupils perceived riverscapes with a high water dynamic as best for recreation, while water bodies with low water levels and algae, dry river sites, floods and littered trails were disliked. Heterogeneity among the pupils was found with one smaller segment preferring settings with high water dynamic and low human impact, while the larger one preferred settings with more human impact and low water dynamic. This segment that shows some dislike for natural conditions had less experience with rivers and scored lower on natural river-related attitudes and perceptions. Implications for recreational river planning and aesthetic assessments are derived.     

Calcium-induced membrane microdomains trigger plant phospholipase D activity

Plant alpha-type phospholipase D proteins are calcium-dependent, lipolytic enzymes. The morphology of the aggregates of their phospholipid substrate fundamentally defines the interaction between the enzyme and the surface. Here we demonstrate that the Ca(2+)-induced generation of membrane microdomains dramatically activates alpha-type phospholipase D from white cabbage. 500-fold stimulation was observed upon incorporation of 10 mol % 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (POPA) into 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) vesicles in the presence of Ca(2+) ions. Enhanced association of PLDalpha2 with phospholipid surfaces containing anionic components was indicated by lag phase analysis and film balance measurements. Differential scanning calorimetry showed that the POPA-specific activation correlates with the phase behavior of the POPC/POPA vesicles in the presence of Ca(2+) ions. We conclude from the results that the Ca(2+)-induced formation of POPA microdomains is the crucial parameter that facilitates the binding of PLD to the phospholipid surface and suggest that this effect serves as a cellular switch for controlling PLD activity.     

The approximate solution of the Euclidean traveling salesman problem on a CRAY X-MP

The efficient use of MIMD computers calls for a careful choice of adequate algorithms as for an implementation taking into account the particular architecture. To demonstrate these facts, a parallel algorithm to find an approximate solution to the Euclidean Traveling Salesman Problem (ETSP) is presented. The algorithm is a parallelization of Karp's partitioning algorithm. It is a divide-and-conquer method for solving the ETSP approximately. Since the successor vertex to any vertex in the tour is usually a nearby vertex, the problem can be ‘geographically’ partitioned into subproblems which then can be solved independently. The resulting subtours can be combined into a single tour which is an approximate solution to the ETSP. The algorithm is implemented on a CRAY X-MP with two and four processors, and results using macrotasking and microtasking are presented.     

Lactic acid bacteria in an alginate film inhibit Listeria monocytogenes growth on smoked salmon

Antimicrobial packaging with lactic acid bacteria incorporated into the film matrix is a novel approach for controlling the growth of food-borne pathogens in ready-to-eat food. The overall objective of this study was to assess the effect of two strains of lactic acid bacteria (LAB) and nisin trapped in an alginate matrix, on Listeria monocytogenes growth on vacuum packed cold-smoked salmon. A film was formulated containing two LAB strains and nisin (100 IU/mL). LAB viability and bacteriocin like substance production (BLS) were assessed using the plate antagonism technique. To check the film antagonistic activity, pieces of salmon (4.0 × 4.0 cm²), inoculated with L. monocytogenes at a final concentration of 10⁴ CFU/cm², were covered with film containing both LAB strains plus nisin and stored at 4 °C. L. monocytogenes colonies on OXA agar were counted after 0, 7, 14, 21 and 28 days to evaluate pathogen inhibition. All treatments led to effective diffusion of the BLS that inhibited L. monocytogenes for 20 days after film preparation, with inhibition zones of 5.7 cm² for film coupons of 8 mm in diameter. After 28 days, salmon pieces covered with the film without inhibitors showed an increase of 2.4 log cycles in L. monocytogenes growth. In contrast, films with either LAB strain or a combination of both strains and nisin had a bacteriostatic effect on the pathogen over a period of 28 days, which exceeds the industrial standard shelf life for smoked salmon. The results demonstrate that these films inhibit L. monocytogenes growth on salmon during refrigerated storage.     

Stability of Older Adults' Preferences for Life-Sustaining Medical Treatment.

The use of instructional advance directives assumes that preferences for life-sustaining medical treatment remain stable over time and across changes in life condition. A sample of 332 older adults recorded their preferences for 4 life-sustaining treatments in 9 illness scenarios. These preferences were elicited again 1 and 2 years after the original interview. Overall, preferences for life-sustaining treatment were moderately stable over time, but stability varied significantly across judgments. Preferences were most stable for illness scenarios that were most and least serious and for decisions to refuse treatment. Age, gender, education, and prior completion of an advance directive were all related to preference stability, and evidence indicated that declines in physical or psychological functioning resulted in decreased interest in life-sustaining treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does Class Size in First Grade Relate to Children's Academic and Social Performance or Observed Classroom Processes?

This study evaluated the extent to which first-grade class size predicted child outcomes and observed classroom processes for 651 children (in separate classrooms). Analyses examined observed child-adult ratios and teacher-reported class sizes. Smaller classrooms showed higher quality instructional and emotional support, although children were somewhat less likely to be engaged. Teachers in smaller classes rated typical children in those classes as more socially skilled and as showing less externalizing behavior and reported more closeness toward them. Children in smaller classes performed better on literacy skills. Larger classrooms showed more group activities directed by the teacher, teachers and children interacted more often, and children were more often engaged. Lower class sizes were not of more benefit (or harm) as a function of the child's family income. First-grade class size in the range typical of present-day classrooms in the United States predicts classroom social and instructional processes as well as relative changes in social and literacy outcomes from kindergarten to first grade. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Job Strain or Healthy Work: A Question of Task Design.

Objectively evaluated task requirements were used to classify jobs causing high strain, low strain, and jobs conducive to personal development. Effects of these job characteristics on psychophysiological outcomes were tested in 241 employees by using 24-hr ambulatory assessment of blood pressure (BP), heart rate, and mood. Self-reports about job characteristics showed that employees working in jobs conducive to personal development perceived the highest job demands and decision latitude. They also showed a healthy cardiovascular behavior with increased diastolic BP at work and its strong unwinding at night. Although self-reports about job characteristics did not differ between low- and high-strain jobs, employees exposed to high-strain jobs had higher systolic and diastolic BP during work and more often a disturbed relaxation ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A∕E∕C Teamwork: A Collaborative Design and Learning Space

This paper describes an ongoing effort focused on combined research and curriculum development for multidisciplinary, geographically distributed architecture∕engineering∕construction (A∕E∕C) teamwork. It presents a model for a distributed A∕E∕C learning environment and an Internet-based Web-mediated collaboration tool kit. The distributed learning environment includes six universities from Europe, Japan, and the United States. The tool kit is aimed to assist team members and owners (1) capture and share knowledge and information related to a specific project; (2) navigate through the archived knowledge and information; and (3) evaluate and explain the product's performance. The A∕E∕C course offered at Stanford University acts as a testbed for cutting-edge information technologies and a forum to teach new generations of professionals how to team up with practitioners from other disciplines and take advantage of information technology to produce a better, faster, more economical product. The paper presents new assessment metrics to monitor students' cross-disciplinary learning experience and track programmatic changes. The paper concludes with challenges and quandaries regarding the impact of information technologies on team performance and behavior.