Influences of subzero thermal acclimation on mitochondrial membrane composition of temperate zone marine bivalve mollusks

The phospholipid and phospholipid fatty acid composition of gill mitochondrial membranes from two temperate zone marine bivalve mollusks, the quahog, Mercenaria mercenaria, and the American oyster, Crassostrea virginica, were examined after acclimation to 12 and −1°C. Cardiolipin (CL) was the only phospholipid with proportions altered upon acclimation to −1°C, increasing 188% in the mitochondrial membranes of M. mercenaria. Although the ratio of bilayer stabilizing to destabilizing lipids is frequently associated with cold acclimation in ectothermic species, no change was found in this ratio in either of the species. Polyunsaturated fatty acids (PUFA) were found only to increase in C. virginica with cold acclimation, with total n-3 PUFA increasing in the phospholipid phosphatidylethanolamine, total n-6 PUFA increasing in CL, and total PUFA increasing in phosphatidylinositol. Monounsaturated fatty acids, not PUFA, were found to have increased in M. mercenaria, with 18:1n−9 increasing by 150% in CL, and 20∶1 increasing in both CL and phosphatidylcholine, by 146 and 192%, respectively. These manipulations of membrane phospholipid and fatty acid composition may represent an attempt by these species to help maintain membrane function at low temperatures.     

A Genetic Programming Approach to Rainfall-Runoff Modelling

Planning for sustainable development of water resources relies crucially on the data available. Continuous hydrologic simulation based on conceptual models has proved to be the appropriate tool for studying rainfall-runoff processes and for providing necessary data. In recent years, artificial neural networks have emerged as a novel identification technique for the modelling of hydrological processes. However, they represent their knowledge in terms of a weight matrix that is not accessible to human understanding at present. This paper introduces genetic programming, which is an evolutionary computing method that provides a transparent and structured system identification, to rainfall-runoff modelling. The genetic-programming approach is applied to flow prediction for the Kirkton catchment in Scotland (U.K.). The results obtained are compared to those attained using two optimally calibrated conceptual models and an artificial neural network. Correlations identified using data-driven approaches (genetic programming and neural network) are surprising in their consistency considering the relative size of the models and the number of variables included. These results also compare favourably with the conceptual models.     

Active centers, catalytic behavior, symbiosis and redox properties of MoV(Nb,Ta)TeO ammoxidation catalysts

Selective as well as waste forming active centers were defined for MoVNbTeO and MoVTaTeO catalysts in the ammoxidation of propane to acrylonitrile and all catalytic functionalities were assigned to specific elements at the respective active centers. Symbiosis between M1 and M2 phases of these catalysts was observed, with phase cooperation being more extensive in the Nb than Ta containing compositions. The difference in catalytic effectiveness arises most likely because contact and surface area exposure of the two respective, cooperating phase pairs are not equal. The M1 phase of the catalysts is reducible by propane and ammonia in the absence of dioxygen and is regenerable to its original, fully oxidized state by dioxygen (air). No structural collapse is observed even after 120 C₃H₈ + NH₃ reduction pulses. The so induced reduction of the catalyst extends up to 70 layers deep. The product distribution over the first few pulses is very similar to that under catalytic conditions, supporting the concept that lattice oxygen is involved in the catalytic ammoxidation process. Therefore, the ammoxidation of paraffins is a redox process, as is of course the well-known olefin ammoxidation process.     

New Materials and Processes for Integrated Optics

Materials and processes for integrated optics are faced with increasing demands from telecommunications and instrumentation applications. Progress in three aspects of novel materials and processes are described: titanium-diffused sapphire waveguides and lasers, interferometric excimer laser ablation of waveguide gratings, and surface studies by waveguide surface plasmon resonance.     

Constructability State of Practice Report

This report reviews guidance on constructability programs from a variety of sources and presents the current practice of constructability. The advice of several organizations and researchers is summarized to describe expectations for ideal constructability. Actual current constructability practice, based on results and analysis of a Constructability State of Practice survey, is described. Approximately 100 owners, architects, engineers, consultants, contractors, and construction managers answered the survey’s ten questions and provided written comments. The results provide a picture of current constructability practices in the architecture, engineering, and construction (AEC) industry and progress in recent years. Major conclusions include: (1) constructability has gained acceptance throughout the industry; (2) constructability efforts are clearly beginning in early project phases; (3) a wide variety of constructability techniques and new technologies are being implemented; and (4) obstacles to improving constructability remain, but may be changing. Finally, recommendations are provided based on areas where constructability practice can still be improved. This report is relevant to both industry practitioners and researchers.     

News & notes.

This column presents information of interest to Division 26 members. Included are a candidate's statement from Division member Ludy T. Benjamin, Jr., who is running for President of the American Psychological Association. Also included are a report on the February 1998 Meeting of the APA Council of Representatives; information about the Wallace Russell Fund, nominations for division offices, fellows nominations, and division membership; meeting announcements; and information about access restrictions to the Stanley Milgram papers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Event-related potentials elicited by automatic targets: A dual-task analysis.

Investigated the role of limited capacity processes in the detection of automatic targets in a dual-task paradigm using both behavioral and event-related potential (ERP) measures. Six right-handed undergraduates served as Ss. An automatic detection task was paired with another concurrent discrimination while the relative importance of each task was systematically varied. The resulting performance operating characteristic showed that both the speed and accuracy of automatic detection responses were affected by the allocation of attention. Reductions in the accuracy of each task were accompanied by reductions in the amplitude of a late-positive component of the ERP (P300). The latency of the P300 component elicited by automatic targets was increased in dual-task conditions. A comparison of behavioral and ERP measures suggested the involvement of 2 separate limited-capacity processes in automatic detection: one concerned with the formation of an episodic representation of target occurrence and the other with the execution of rapid motor responses. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimism, neuroticism, coping, and symptom reports: An alternative interpretation of the Life Orientation Test.

Found in two studies that the Life Orientation Test (LOT) had limited discriminant validity relative to measures of neuroticism. Furthermore, although previous correlations of the LOT with measures of symptom reports and coping behaviors were replicated, these correlations were eliminated when neuroticism was controlled. In contrast, the correlations of symptoms and coping with neuroticism remained significant when LOT scores were controlled. Thus, the LOT is virtually indistinguishable from measures of neuroticism, and previously reported findings using this scale are perhaps more parsimoniously interpreted as reflecting neuroticism rather than optimism. These findings are discussed in terms of existing support for models of optimism and self-control and general methodological issues in studies of personality and health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning disabilities: Policy issues and promising approaches.

The current status of knowledge concerning learning disabilities is reviewed with respect to areas of consensus and areas of disagreement about this phenomenon. The adequacy of the knowledge base is evaluated, and implications for social policies regarding the definition, diagnosis, treatment, and education of learning disabled children are drawn. (PsycINFO Database Record (c) 2010 APA, all rights reserved)