Information Search And Causal Analysis: The Role Of Personal Involvement

How do people explain events with multiple possible causes? Past research has indicated that perceivers are usually content with discovering single, sufficient causes for observed events as opposed to considering multiple causation. We argue that this tendency for information search to be directed toward the role of single causes is, primarily, a manifestation of low involvement processing; perceivers will search for information relevant to multiple possible causes when they are suitably motivated to arrive at accurate causal conclusions.;Three experiments were conducted to test this hypothesis. High involvement subjects were told that the purpose of the study was to assess their ability to determine accurately why events occur. These instructions were designed to increases the costs associated with inaccurate judgments. Low involvement subjects were told that there were no right or wrong approaches to determining the causes of events.;All subjects were provided with an event and given the opportunity to search for additional information about why the event occurred. The basic prediction in these studies was that low involvement subjects would be content with identifying the contribution of single sufficient causes for the events. Thus, when a likely cause was known (Experiment 1) or hypothesized (Experiments 2 and 3) to exist, low involvement subjects were expected to seek information about the role of the likely cause, as opposed to seeking information relevant to other potentially relevant causes. High involvement subjects were expected to search for information relevant to all possible causes, in order to achieve a complete (rather than sufficient) causal account.;Experments 1 and 3 utilized a structured information search methodology, whereby subjects were allowed to select questions pertinent to three nonexclusive causes. In Experiment 2, subjects were allowed to generate their own questions relevant to why the event occurred.;The results provided some support for predictions. Moreover, the current research suggested that (1) the complexity and plausibility of known causes, (2) cues suggesting alternative causes, and (3) the extremity and familiarity of events are potentially important variables that influence the search for information about the causes of events. Discussion focuses on limitations of the present research and future research directions. (Abstract shortened with permission of author.

High-Resolution, Real-Space Imaging of Conformational Structures of Poly-L-Proline Helixes

In 1954, Edsall postulated that the imino-acid proline, which is a frequently found constituent of protein molecules, is a key determinant to the three-dimensional architecture of proteins. It not only should play a fundamental role in stabilizing helical structures of polypeptides, it should allow for sharp bends and even for a complete reversal of the direction of a helix looping back on itself. No direct evidence has yet been published to prove this prediction. Using scanning tunneling microscopy, we have presented high-resolution, real-space images of two conformations of poly-L-proline, where one structure clearly exhibits the predicted 180° back-folding behavior. The measured length, 1.89 nm, of the repeating unit cells agrees with available X-ray data for poly-L-proline I with cis-peptide bonds. We further observe aggregated poly-L-proline II, consisting of highly-ordered, periodically and parallel-linked trans-peptide chains which are 2.4 nm apart from each other. Stacking of these aggregates with their orientation rotated by 90° is also observed

Synergistic interaction of the cellulosome integrating protein (CipA) from Clostridium thermocellum with a cellulosomal endoglucanase

AbstractActivity of a cellulosomal endoglucanase (endoglucanase E; EGE) from Clostridium thermocellum against two crystalline forms of cellulose was enhanced by combination with the cellulosome integrating protein (CipA), but CipA did not enhance EGE activity against amorphous cellulose, even though it was able to bind to it. Similarly, CipA added in trans to genetically truncated EGE that was unable to combine with it nevertheless enhanced EGE activity against crystalline cellulose. These results indicate that the CipA cellulose binding domain does not mediate an increase in activity solely by bringing the catalytic subunits of the cellulosome complex into intimate contact with the substrate

Effects of Betaine on Protein Deposition in Growing Cattle with Modulated Methyl Group Status

Objective: This study was conducted to evaluate effects of guanidinoacetic acid and creatine supplementation in the presence or absence of supplemental betaine on lean tissue growth in growing cattle. Study Description: Seven ruminally cannulated Holstein steers (417 lb) were used in an experiment where each steer received each of six treatments. The first treatment set was conducted via abomasal infusion of a saline solution (control), 15 g/day guanidinoacetic acid (GAA), or 16.8 g/day creatine, and the second set was conducted via abomasal infusion of 0 or 5.6 g/day betaine; all treatment combinations were represented. Complete collection of urine and feces was used to determine nitrogen retention as a measure of protein deposition. Steers were limit-fed a corn-based diet similar to that of a production-type setting. Bottom line: Supplementing 5.6 g/day betaine increased lean tissue growth in growing steers fed corn-based diets

Twisted k-graph algebras associated to Bratteli diagrams

Given a system of coverings of k-graphs, we show that the cohomology of the resulting (k+1)-graph is isomorphic to that of any one of the k-graphs in the system. We then consider Bratteli diagrams of 2-graphs whose twisted C*-algebras are matrix algebras over noncommutative tori. For such systems we calculate the ordered K-theory and the gauge-invariant semifinite traces of the resulting 3-graph C*-algebras. We deduce that every simple C*-algebra of this form is Morita equivalent to the C*-algebra of a rank-2 Bratteli diagram in the sense of Pask-Raeburn-R{\o}rdam-Sims.Comment: 28 pages, pictures prepared using tik