Microwave assisted barking of frozen wood

Thawing pulpwood with microwave energy could be an effective means to improve winter barking operations in Canadian interior mills. Complete bark thawing requires 140 MJ per tonne of wood for average 25 cm diameter logs at 90 mass % moisture, dry basis. However, complete thawing may not be necessary, as warming both spruce and aspen bark from ?20°C to ?5°C, decreases the bark/wood bond strength from 2.5–4.5 MPa to room temperature values of 0.5–1.5 MPa. This improves the economics of winter operation, but the expenditure for capital which has no year-round use is not easily justified. Also the design of safe large-scale microwave generators and applicators remains a technical challenge.     

DNA aptamers binding to multiple prevalent M-types of Streptococcus pyogenes

This paper describes the selection of high affinity DNA aptamers binding to multiple M-types of the pathogenic species Streptococcus pyogenes (Group A Streptococcus or GAS). Unlike common aptamer selection techniques that use purified molecules of a monoclonal cell population as targets, this work has achieved the selection of aptamers against the various M-types of S. pyogenes. Cell mixtures containing equal numbers of the 10 most prevalent S. pyogenes M-types were incubated with 80-nucleotide DNA libraries, centrifuged, and washed to separate cell-bound from unbound DNA sequences. The DNA bound to the cells was amplified using the polymerase chain reaction, and the amplicons were tested for their binding to the target cells. The amplicons were also used as new DNA libraries for subsequent rounds of selection. Cloning, sequencing, and subsequent analysis of selected aptamers showed that they bind preferentially to GAS over other common and related bacteria. Resultant DNA aptamers showed strong and preferential binding to GAS, including the 10 most prevalent GAS M-types and another 10 minor M-types tested. Estimated K(d) values were in the range of 4 to 86 nM. Two aptamers, 20A24P and 15A3P (with estimated binding dissociation constants of 9 and 10 nM, respectively), are particularly promising. These aptamers could potentially be used to improve the detection of GAS, a pathogen that is the causative agent of many infectious diseases, most notably strep throat.     

High Performance Steel: Research Front—Historical Account of Research Activities

This paper provides a summary of the major research studies conducted or being conducted in the U.S., to address design issues related to use of high performance steel (HPS) in bridge construction. Emphasis of the paper is on the work related to HPS-485W steel, which has specified minimum yield strength of 485 MPa (70 ksi). Design issues that are addressed in this paper include (1) flexural capacity of compact and noncompact HPS sections in negative bending; (2) issues related to ductility of HPS composite girders in the positive sections (this section presents a simplified ductility check for composite plate girders); (3) tensile ductility of HPS plates; (4) shear capacity of the hybrid steel plate girders; (5) live load deflections; and (6) brief overview of the work that is underway to develop innovative bridge configurations capable of incorporating the advantages of HPS.     

No pain, no gain: The conditions under which upward comparisons lead to better performance.

In 3 studies, the authors explored the relation between threatening upward social comparisons and performance. In an initial study, participants were exposed to comparison targets who either threatened or boosted self-evaluations and then completed a performance task. Participants exposed to the threatening target performed better than those in a control group, whereas those exposed to the nonthreatening target performed worse. In Study 2, self-affirmation prior to comparison with threatening targets eliminated performance improvements. In Study 3, performance improvements were found only when the performance domain was different from the domain of success of the comparison target. These boundary conditions suggest that increases in performance following social comparison arise from individuals' motivations to maintain and repair self-evaluations. Implications for the study of the behavioral consequences of social comparison are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulation of Specific Regions of the Parabrachial Nucleus Elicits Ingestive Oromotor Behaviors in Conscious Rats.

The "waist" area and external subnuclei of the parabrachial nucleus (PBN) have been implicated in the processing of gustatory information, yet their behavioral roles are not clearly defined. In the current study, areas within and surrounding the PBN were stimulated while oromotor behaviors were monitored in conscious rats. Electrical and chemical (100 mM glutamate) stimulation of the waist area increased ingestive oromotor behaviors over baseline (p     

The magneto-electric effect in molten salts—III. Measurement of the thermomagneto-electric effect in molten potassium nitrate

The joint action of two rectangular direct and constant fields (electric and magnetic) on molten potassium nitrate, produces local temperature variations in the Lorentz force direction. This thermal effect is studied as a function of the magneto-electric stress and also of the temperature of the molten electrolyte. The results are different depending on the initial thermal conditions; they are compared with the previous magneto-electric voltage measurements.     

Is an attributional analysis of the learned helplessness phenomenon viable? A critique of the Abramson-Seligman-Teasdale reformulation.

Considers that the reformulation of the learned helplessness model by L. Y. Abramson et al (see record 1979-00305-001) overcomes many of the shortcomings inherent in the original model and raises questions for future research on helplessness and depression. A critique is made of the various components of the reformulated model: (a) Some questions are raised about the importance of attributions in predicting reactions to uncontrollable outcomes, including whether people make attributions and whether there is a relationship between attributions and behavior. (b) It is questioned whether the dimensions of attribution selected by Abramson et al are the most significant ones in predicting the nature and magnitude of behavioral deficits. (c) The possibility is raised that factors other than attributions and expectations for future control may influence reactions to uncontrollable outcomes. Certain characteristics of the outcome, such as whether it is expected and whether people are able to find meaning in it, may be important. (d) The account of the cognitive, motivational, and affective responses to lack of control is examined. The present authors feel that 2 basic questions are left unanswered: What is the relationship between the various deficits that are proposed, and when does exposure to lack of control result in deficits, and when does it result in facilitated performance? (e) The reformulated learned helplessness model of depression is examined. The model is seen to raise questions about the direction of causality between attributions, expectations, and depression. (53 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distinguishing optimism from pessimism: Relations to fundamental dimensions of mood and personality.

Contrary to unidimensional conceptions of optimism and pessimism, factor analysis of 2 widely used instruments revealed that optimism and pessimism are empirically differentiable, but related, constructs. Moreover, consistent with expectations, optimism and pessimism were differentially linked with fundamental dimensions of mood and personality. Pessimism was principally associated with neuroticism and negative affect. Optimism was primarily associated with extraversion an positive affect. Findings are discussed with reference to current conceptual and measurement models of optimism and pessimism and their relations to broad dimensions of mood and personality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Obituary: Philip Brickman (1943-1982).

Presents an obituary for Philip Brickman, whose distinguished career in social psychology focused on issues such as justice, happiness, pain, inequality, helping, and coping. From 1968 to 1978, he was a faculty member in the psychology department at Northwestern University. In 1979, he went to the University of Michigan, where he joined the faculty as professor in the Psychology Department and director of the Research Center for Group Dynamics at the Institute for Social Research. By the time of his death, Brickman had published over 50 articles and book chapters, many of them very well known and widely cited. In addition to his published work, he enriched the field through his participation in several professional societies. He had served on the Council of APA's Division 9 (The Society for the Psychological Study of Social Issues; SPSSI) and on the Executive Committee of Division 8 (Personality and Social Psychology), where he provided valuable leadership during the crisis in research funding that occurred during the early years of the first Reagan administration. Brickman passed away in 1982. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selection criteria for the analysis of data-driven clusters in cerebral FMRI

Functional MRI (fMRI) may be possible without a priori models of the cerebral hemodynamic response. First, such data-driven fMRI requires that all cerebral territories with distinct patterns be identified. Second, a systematic selection method is necessary to prevent the subjective interpretation of the identified territories. This paper addresses the second point by proposing a novel method for the automated interpretation of identified territories in data-driven fMRI. Selection criteria are formulated using: 1) the temporal cross-correlation between each identified territory and the paradigm and 2) the spatial contiguity of the corresponding voxel map. Ten event-design fMRI data sets are analyzed with one prominent algorithm, fuzzy c-means clustering, before applying the selection criteria. For comparison, these data are also analyzed with an established, model-based method: statistical parametric mapping. Both methods produced similar results and identified potential activation in the expected territory of the sensorimotor cortex in all ten data sets. Moreover, the proposed method classified distinct territories in separate clusters. Selected clusters have a mean temporal correlation coefficient of 0.39+/-0.07 (n=19) with a mean 2.7+/-1.4 second response delay. At most, four separate contiguous territories were observed in 87% of these clusters. These results suggest that the proposed method may be effective for exploratory fMRI studies where the hemodynamic response is perturbed during cerebrovascular disease.