Managing rivers for fisheries and livelihoods: how can we do it better?

The growing attention being given to improving water productivity at the catchment level has given rise to increased interest in the contribution of aquatic ecosystems and in particular fisheries to reducing rural poverty and improving food security. There is growing recognition that these natural resources have an important role to play in pro-poor water management in many of the world's river basins, but that capacity to optimize these benefits is constrained by a lack of appropriate technologies and tools to do so. The present paper provides an overview of the current state of understanding of these issues and identifies a number of challenges to be addressed, namely the need to: (i) build wider understanding of the value of river fisheries; (ii) understand the water requirements for sustaining river fisheries; and (iii) develop governance arrangements that bring fisheries to the decision-making table. It concludes by distilling from recent reviews of river fisheries valuation, environmental flows, and governance, a set of specific directions that need to be taken in order to meet these challenges.     

Epoxy paint failure in B-52 fuel tanks: Part II. Influence of DIEGME concentration in the fuel on the failure process

A model has been proposed to explain the failure of the original BMS10-39 epoxy paint on upper vertical surfaces in B-52 fuel tanks. The model involves interaction of the paint with DIEGME, a fuel system ice inhibitor (FSII) in jet fuel, that is distilled from the liquid fuel. In this communication, distillation experiments used to support the model are refined to better match the mass transfer of vapor from fuel in a B-52 fuel tank at close to room temperature. The interaction of these lower temperature distillates with the paint affirms the earlier model. On the basis of these experiments it is proposed that paint failure may be controlled or eliminated by reducing the level of DIEGME in the fuel. Proposed changes in military jet fuel composition are detailed.     

Fabrication and characterization of planar and channel polymer wave guides. I. Plasma-polymerized HMDS films

Plasma-polymerized hexamethyldisiloxane (HMDS) films have been prepared as both planar and channel wave guides. The optical attenuation results measured in both the planar and channel HMDS wave guides were found to be similar, thus demonstrating that the inherent solvent resistance and chemical inertness of the plasma polymerized films allows the use of common photoresist techniques, including application of the photoresist, photomasking, and subsequent etching. This may be contrasted with wave guides made from conventional polymers, where careful consideration must be given to photoresist/polymer compatibility, because the photoresist solvents may adversely affect the underlying polymer and lead to degradation of the material during processing. © 1995 John Wiley & Sons, Inc.     

Approximate sensitivity analysis for acyclic Markov reliability models

Acyclic Markov chains are frequently used for reliability analysis of nonmaintained mission-critical computer-based systems. Since traditional sensitivity (or importance) analysis using Markov chains can be computationally expensive, an approximate approach is presented which is easy to compute and which performs quite well in test cases. This approach is presented in terms of a Markov chain which is used for solving a dynamic fault-tree, but the approach applies to any acyclic Markov reliability model.     

A connectionist implementation of the theory of planned behavior: Association of beliefs with exercise intention.

The theory of planned behavior suggests attitudes are a product of salient beliefs. This study examined whether aggregating salient beliefs was plausible within a more biologically centered information-processing environment. A neural network was used to examine associations among beliefs relating to exercise intention. Data on intentions and behavioral, normative, and control beliefs from 114 respondents were used to train (by error backpropagation) a neural network to associate beliefs with intention. The R2 between the network's estimated and self-reported intention was .66. The network's representation comprised 6 belief profiles associated with high, moderate, or low behavioral intention. The neural network accommodated complex relationships among beliefs and belief-intention associations and indicated how high-level constructs such as attitudes may be viewed as the best fit (compromise state) between aroused beliefs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of linguistic structure on children's ability to isolate initial consonants.

In 4 experiments, preschoolers and kindergartners were asked to pronounce the initial consonants of spoken words. Children performed better on short words, such as bay, than on long words, such as bonus. Words with initial consonant clusters, such as brow, were more difficult for the children than words without initial consonant clusters, such as bar. A consonant cluster at the end of the word did not harm performance. Children did relatively well on words like suppose, for which the word's 1st syllable, /s/, constitutes a correct answer on the initial consonant isolation task. Children did more poorly on words like satin, for which this was not the case. Thus, the linguistic structure of a word affects children's ability to isolate the initial consonant. Implications for the design of phonemic awareness instruction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and prospective memory: Examining the influences of self-initiated retrieval processes.

Past research has frequently failed to find age differences in prospective memory. This article tested the possibility that age differences would be more likely to emerge on a prospective memory task that was high in self-initiated retrieval. In the 1st experiment, participants were asked to perform an action every 10 min (a time-based task presumed to be high in self-initiated retrieval); in the 2nd experiment, participants were asked to perform an action whenever a particular word was presented (an event-based task presumed to be relatively low in self-initiated retrieval). Age differences were found with the time-based task but not with the event-based task. This pattern of age differences was again found in a 3rd experiment in which a new experimental procedure was used and the nature of the prospective memory task was directly varied. Generally, the results suggest that self-initiated retrieval processes are an important component of age-related differences across both retrospective and prospective memory tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)