Abiotic Attributes Surrounding Alluvial Islands Generate Critical Fish Habitat

Identifying the appropriate scale at which habitat is biologically relevant to riverine fishes in large, sand‐dominated rivers is a challenge. Alluvial islands are important to several of these fishes throughout the central USA, but there is a paucity of information on island habitat features that restoration efforts should try to replicate. We determined the physical characteristics of two island complexes in the middle Mississippi River that facilitate the settlement and survival of age‐0 shovelnose sturgeon Scaphirhynchus platorynchus at relatively large (mean 39,000 m²) and small (mean 320 m²) scales. Depth (m), flow rate (m s^?1), substrate (sand, rock, silt) and vegetation were quantified at these two scales using hydroacoustic techniques (split‐beam sonar and acoustic Doppler current profiler). Abiotic attributes in the surrounding littoral zone of the island complexes were highly correlated but differed depending on location. At the coarse spatial scale, vegetation was positively related to shovelnose sturgeon abundance. At the fine spatial scale, age‐0 shovelnose sturgeon were restricted to flow rates < 0.89 m s^?1, with abundance peaking at about 0.40 m s^?1. However, heterogeneity in depth and flow was important, and sturgeon abundance peaked at intermediate variability in these two abiotic attributes. A computer‐generated model of the habitat surrounding islands suggests that these habitats are diverse and may provide flow refugia and foraging patches for shovelnose sturgeon. We submit the results presented here that can contribute to a hierarchical model for island restoration in large rivers. Copyright © 2014 John Wiley & Sons, Ltd.     

Effect of crystalline structure on the trapped radical spectra of irradiated cellulose

The effects of crystalline modification of cellulose and of water on the ESR spectra generated by the trapped free radicals in gamma-irradiated celluloses were investigated for cotton cellulose I, II, III, and IV, partially decrystallized cotton cellulose, ballmilled cotton cellulose, hydrocelluloses of cellulose III and IV, and ramie. On irradiation of the celluloses, free radicals were formed on the cellulose molecule, probably following dehydrogenation or chain cleavage. The free radicals located within the less ordered or amorphous regions of the cellulose reacted readily with water and were terminated. The radicals located within the more ordered regions of the celluloses could be made accessible to reaction with water by the interaction of the celluloses with solvents which caused dimensional changes in the cellulosic structure. In the highly ordered regions of the celluloses, even after long periods of time in solvents which caused large dimensional changes in the cellulosic structure, the trapped free radicals were not terminated by reaction with solvent or water. The ESR spectra of the irradiated, dried celluloses were determined at ?160°C, the single-line spectra recorded had line widths of about 18-24 gauss. On the absorption of water by the irradiated celluloses, the ESR spectra changed and were dependent on the crystalline structure of the irradiated celluloses. The effects of different arrangements of the irradiated celluloses, as shown by their trapped radical spectra, particularly after interaction with water, were discussed.     

Automation cueing modulates cerebral blood flow and vigilance in a simulated air traffic control task

Automation cueing of impending hazards or critical signals can have both beneficial and deleterious effects on the human operator, depending on automation reliability. To assess these effects, transcranial Doppler sonography (TCD), a low-cost non-invasive procedure that allows continuous monitoring of blood flow in the left and right cerebral hemispheres, was used to examine the influence of automation cues of varying reliability on vigilance performance in a 40-min simulated air traffic control task. Four levels of automation cue reliability (100, 80 and 40% reliable cueing and a no-cue control) were combined factorially with two levels of critical signal salience (high and low). For both levels of signal salience, the detection rate of critical signals was very high and remained stable over time with 100% cue-reliability, but declined over time in the remaining cue conditions, so that, by the end of the task, performance efficiency was best in the 100% condition followed in order by the 80%, 40%, and no-cue conditions. These performance effects for cueing were very closely mirrored by changes in cerebral blood flow in the right (but not the left) hemisphere in conjunction with low salience signals. The results fit well with an attentional resource model of vigilance and show that cerebral blood flow provides a metabolic index of the utilization of information-processing resources during sustained attention. The demonstration of systematic modulation of cerebral blood flow with time on task, automation cueing and signal salience also provides strong evidence for a right hemispheric brain system that is involved in the functional control of vigilance performance over time. Measurement of the activation of this system, as a reflection of operator mental workload, can, therefore, inform the design of optimal automation cueing.     

Fish Movements and Passage Through a Water Control Structure: River Stage and Floodplain Connectivity

The St. John's Bayou water control structure near New Madrid, MO, connects the main Mississippi River to two large backwater areas called the New Madrid Floodway and St. John's Bayou. While this area has been altered, the New Madrid Floodway and St. John's Bayou account for the only substantial portion of the historic Mississippi River floodplain that remains and provides the only critical connection between backwater/floodplain habitat and the river. Fish passage was evaluated during April–December 2010 using ultrasonic telemetry. Stationary receivers were placed strategically at five locations above and below the structure in St. John's Bayou, in the floodway and the outlet to the Mississippi River. A total of 100 individuals representing 14 species were tagged. Total number of detections during an 8‐month period was 1 264 717. Fifteen individuals representing five species moved into the Mississippi and Ohio rivers; seven individuals returned to St. John's Bayou. Thirteen of the 14 species moved upstream through the structure. Of the 85 individuals that stayed in the bayou, 29 fish passed through the structure for a total of 92 passage events. The downstream : upstream passage was roughly 50:50. Passage was correlated with river rise, with frequency of passage being higher in spring, but passage occurred each month during the study. Copyright © 2015 John Wiley & Sons, Ltd.     

The Search for Authenticity in Drawing

In this article we describe a program for teaching drawing developed at the Oregon School of Design, discuss the philosophy behind our methods, and show some extraordinary examples of first-year student work. Our approach challenges the notion of teaching technique to beginning students. Instead, we emphasize the artifice of drawing, destroy student's preconceptions, and teach them to overcome their fear. We propose that authenticity is a state of mind, at the limits of both perception and technique, that enables students to draw things they never thought possible.     

How employees respond to personal offense: The effects of blame attribution, victim status, and offender status on revenge and reconciliation in the workplace.

This study investigated the relationships between blame, victim and offender status, and the pursuit of revenge or reconciliation after a personal offense. Results from a sample of 141 government agency employees showed that blame is positively related to revenge and negatively related to reconciliation. In addition, victim–offender relative status moderated the relation between blame and revenge such that victims who blamed sought revenge more often when the offender's status was lower than their own. The victims' own absolute hierarchical status also moderated this relation such that lower, not higher, status employees who blamed sought revenge more often. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Magnetic Measurement of Liver Iron Stores: Engineering Aspects of a New Scanning Susceptometer Based on High-Temperature Superconductivity

We describe a new approach to the magnetic measurement of liver iron stores, using an instrument that incorporates a combination of permanent magnets and superconducting flux transformers. Instead of traditional low-transition-temperature superconductor (LTS) transformers, the susceptometer employs their high-transition-temperature (HTS) counterparts. This innovation substantially reduces the size and weight of the instrument, allowing the whole assembly to be scanned in a horizontal plane. We report engineering details of the HTS flux transformers, magnet assembly, field sensing, and scan mechanism, and present experimental data to show that scanning susceptometer can determine not only the susceptibility of cylindrical phantom models but also their diameters. We conjecture that further refinements of scanning susceptometer could lead to a form of susceptibility imaging that would enhance the accuracy of measurements of liver iron stores and also lead to new medical applications of the method.     

Decorrelation of spiking variability and improved information transfer through feedforward divisive normalization

Response variability is often positively correlated in pairs of similarly tuned neurons in the visual cortex. Many authors have considered correlated variability to prevent postsynaptic neurons from averaging across large groups of inputs to obtain reliable stimulus estimates. However, a simple average of variability ignores nonlinearities in cortical signal integration. This study shows that feedforward divisive normalization of a neuron's inputs effectively decorrelates their variability. Furthermore, we show that optimal linear estimates of a stimulus parameter that are based on normalized inputs are more accurate than those based on nonnormalized inputs, due partly to reduced correlations, and that these estimates improve with increasing population size up to several thousand neurons. This suggests that neurons may possess a simple mechanism for substantially decorrelating noise in their inputs. Further work is needed to reconcile this conclusion with past evidence that correlated noise impairs visual perception.     

Children's self-talk under conditions of mild anxiety

Two studies are described which used think-aloud (Study 1) and verbal thought-listing (Studies 1 and 2) procedures to assess preadolescent children's self-talk under conditions of mild anxiety. The self-talk reported was coded into six theoretically meaningful categories and the relationship between self-talk type and anxiety (state and trait) examined. Increased levels of anxiety were associated with higher rates of negative self-talk, but not clearly associated with other types of self-talk. These results suggest negative self-talk plays a role in the generation or maintenance of anxiety in normal children. From the data, it is unclear to what extent perceived task difficulty contributes to the relationship between trait anxiety and negative self-talk. Assessment of self-regulation (Study 1) identified higher levels of anxiety in children reporting awareness of strategies for managing their anxiety.