Ecological patterns of fish distribution in the Slave River Delta region,Northwest Territories,Canada, as relayed by traditional knowledge and Western science

Indigenous community members along the Slave River in Canada have voiced their concerns for the health of ecosystems under pressure from resource extraction, hydroelectric development and global climate change. We present a test case of traditional knowledge and scientific results about the spawning and migration patterns of fish in the Slave River and Delta. This dual knowledge system approach elucidates the broader connectivity of local study regions and can improve monitoring programmes by extending beyond the usual context/confines of the present or recent past, increasing the spatial and temporal range of system information.     

Ecosystem matters: fish consumption, mercury intake and exposure among fluvial lake fish-eaters

Many studies use the number of fish meals as an estimate of Hg intake, although fish Hg concentrations, even within the same species, can greatly vary. Furthermore, most freshwater advisories only refer to local catch, while market fish advisories only focus on market fish, although both can contribute to Hg body burden. The present study, carried out in lakeside communities from 2 ecosystems in Quebec, Canada, sought to (i) estimate Hg intake from local freshwater sources, hunted waterfowl and market fish and seafood, and (ii) examine the relations between fish consumption, estimated Hg intake and biomarkers of exposure. A total of 238 adults (18-74 years), who had consumed local catch within the past three months, responded to an extensive interview-administered fish and waterfowl frequency questionnaire. Anthropometric measures were taken and a self-administered questionnaire was used to obtain socio-demographic information. Hg intake was estimated as µg Hg/kg body weight/day. Blood and hair samples were analyzed for Hg content. Results showed that persons from one ecosystem ate significantly more fish compared to those from the other (median: 52.1 g/day vs 38.9 g/day), but presented significantly lower concentrations of hair Hg (median: 448.0 ng/g vs 730.5 ng/g), blood organic Hg (median: 1.1 µg/L vs 3.4 µg/L) and inorganic Hg (median: 0.4 µg/L vs 0.8 µg/L). Median daily total Hg intake was 0.080 µg/kg bw/day for the former community and 0.141 µg/kg bw/day for the latter. Overall, 59.5% from the first ecosystem and 41.0% from the other, exceeded the US EPA RfD (0.1 µg/kg bw/day), while 13.2% and 6.0%, respectively, exceeded the Canadian tolerable daily intake (0.47 µg/kg bw/day) for adults. For the two groups, freshwater fish consumption frequency, but not total fish, was positively associated with bioindicators of Hg while estimated Hg intake from freshwater catch as well as from total fish consumption were positively related to Hg biomarkers. There was a positive relation between consumption and estimated Hg intake from freshwater fish and blood inorganic Hg. These findings indicate that the number of fish can be a poor surrogate for Hg exposure. The differences observed here for Hg intake and exposure reflect ecosystem disparities in fish diversity and Hg bioaccumulation. Studies and advisories need to consider Hg fish concentrations and fish-eating patterns in different ecosystems, as well as the contribution of market fish. The relation between fish consumption and inorganic Hg exposure, reported as well in other studies, needs to be further investigated.     

Temporal variability of dissolved P speciation in a eutrophic reservoir--implications for predicating algal growth

Weak-anion exchange chromatography was used to explore the temporal variability in the speciation of dissolved P in the surface layer of a eutrophic reservoir. Authentic free ortho-P ion was the most common form of P on three of the five sampling occasions-including during a bloom of the green algae Botryococcus braunii indicating that the bloom was not P limited. Conversely, the absence of authentic ortho-P during a bloom of the dinoflagellate Ceratium hirundinella suggested the bloom was either P limited or co-limited. These observations were confirmed by algal-growth bioassay experiments.     

Perceived urgency mapping across modalities within a driving context

Hazard mapping is essential to effective driver-vehicle interface (DVI) design. Determining which modality to use for situations of different criticality requires an understanding of the relative impact of signal parameters within each modality on perceptions of urgency and annoyance. Towards this goal we obtained psychometric functions for visual, auditory and tactile interpulse interval (IPI), visual color, signal word, and auditory fundamental frequency on perceptions of urgency, annoyance, and acceptability. Results indicate that manipulation of IPI in the tactile modality, relative to visual and auditory, has greater utility (greater impact on urgency than annoyance). Manipulations of color were generally rated as less annoying and more acceptable than auditory and tactile stimuli; but they were also rated as lower in urgency relative to other modality manipulations. Manipulation of auditory fundamental frequency resulted in high ratings of both urgency and annoyance. Results of the current investigation can be used to guide DVI design and evaluation.     

Review of The mind in context.

Reviews the book, The mind in context edited by Batja Mesquita, et al. (see record 2010-09987-000). The purpose of this edited volume is to challenge a predominant tendency toward an error of essentialism, or the attempt to explain psychological phenomena in terms of internal, static mental entities that are independent of and seemingly hermetically sealed from the outside world. Instead the introductory chapter of The mind in context advances the context principle: that mental processes and behaviour emerge from a profound and complex interaction between person and environment. It is important to note at the outset that a reader seeking an abstracted, sterilized, encyclopaedic list of essential elements making up this perspective would be well advised to look elsewhere. Rather, and in keeping with the theme of the book, the editors have assembled a lively collection of exemplars: chapters by prominent scholars each exploring the influence of context in a focused area of interest. The disadvantage of this approach is that the book can feel somewhat overextended. The significant advantage, however, is that the reader experiences each chapter in the context of the others, a juxtaposition that allows for the emergence of resonances, themes, and common principles across domains. In elaborating on the context principle the contributors to this book emphasise the mind’s mechanisms, situation-sensitivity, and agency over its content, permanence, and passivity. While written in large part by and for social psychologists, the volume should be of interest to any scholar fascinated by the mind’s ecological nature. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Measures of uncertainty

In spite of the fact the engineers are familiar with the idea that physical systems can be modelled in various ways, it is often stated that probability theory is the only way of modelling uncertainties and degrees of belief about those uncertainties. The thesis advanced here is that within certain bounds (which are specified) there are many ways of representing uncertainty. In particular the ideas of probability and fuzzy sets are shown to be entirely compatible. A voting model is used to illustrate the argument before the basis of the formal treatment is outlined. Finally a set of conjectures are advanced about the types of problem that might best be tackled by probabilistic and fuzzy inference.     

Initial investigations into low-cost ultra-fine pitch solderprinting process based on innovative laser printing technology

Advances in electronics packaging and assembly technology are driving increased demand for ultra-fine pitch solder deposition. In this work, innovative solder deposition techniques based on laser printing are investigated for low-cost ultra-fine pitch printing applications. This paper investigates the feasibility of using solder particles in off-the-shelf xerographic technology. The physics of two development systems (dual component and monocomponent) is discussed. This inquisition leads to a discussion of triboelectric charging of the solder toners, coating the solder with thin dielectrics, and charge induction by an applied electric field. This initial investigation explores the basic feasibility of xerographic printing techniques using solder and defines future work