Effects of starvation on energy density of juvenile chum salmon (Oncorhynchus keta) captured in marine waters of Southeastern Alaska

We conducted laboratory starvation experiments on juvenile chum salmon (Oncorhynchus keta) captured in the neritic marine waters of northern Southeast Alaska in June and July 2003. Temporal changes in fish energy density (whole body energy content [WBEC], cal/g dry weight), percent moisture content, wet weight (g), length (mm), and size-related condition residuals were measured in the laboratory and were then compared to long-term field data. Laboratory water temperatures and salinities averaged 9°C and 32 psu in both months. Trends in response variables were similar for both experimental groups, although sampling intervals were limited in July because fewer fish were available (n= 54) than in June (n=101). Overall, for June (45-d experimental period, 9 intervals), WBEC, wet weight, and condition residuals decreased and percent moisture content increased, whereas fork length did not change. For July (20-d experimental period, 5 intervals), WBEC and condition residuals decreased, percent moisture content and fork length increased, and wet weight did not change. WBEC, percent moisture content, and condition residuals fell outside the norm of longterm data ranges within 10–15 days of starvation, and may be more useful than fork length and wet weight for detecting fish condition responses to suboptimal environments

Visual Focus and Sports Performance

The connection between how a physical movement is processed in the brain to how the body physically completes the task is significant in the sports world. Information from the environment must be observed and processed in order to develop a resulting course of action for particular athletic skills. More specifically, the brains of soccer players must smoothly adjust between internal and external cognitive pathways when making sports related decisions thousands of times during games and practices. A study by Wood and Wilson revealed that gaze coordination and aiming accuracy are closely related (2010). The current study extended this study to examine other factors that affect accuracy with and without a keeper under controlled conditions. The aim of the study was to find the connection between visual focus patterns and the development of sports performance execution. Through analyzing the visual focus patterns of participants, compared to how accurate the participants were penalty kicks, we were able to enhance our understanding of how the internal and external cognitive network assigned to making and executing decisions regarding sports related activities could be advanced. It is hypothesized that when gaze coordination exhibits greater external focus, there will be less interference among internal action signals resulting in more accurate performance. Participants completed a series of 24 penalty kicks, performing 6 penalty kicks within each of four conditions: No Keeper/No Target, Keeper/No Target, No Keeper/Target, and Keeper/Target. Having a target indicates that the participant was required to look at a red cardstock (RC) posted to the center of the crossbar before completing their penalty kick. Eye movements were recorded and analyzed alongside the quality of their penalty kicks. Kick quality was measured using velocity of the kick, distance of the shot from the center of the goal, and whether the goal was scored. Eye movement patterns were collected using TOBII eyeglass equipment, which recorded fixation duration, fixation count, visit duration, and visit count measurements among various areas of interest on the goal. There were 7 areas of interest, 6 areas dividing the goal: Top Left (1), Bottom Left (2), Top Center (RC) (3), Bottom Center (4), Top Right (5), Bottom Right (6) and one area of interest for the ball (7). Repeated-measures ANOVA revealed that participants were more accurate when there was no keeper present and when they were required to focus on an external target (RC). In examining eye movement patterns, it was found that the greater the external focus, either on the target or the ball, as indicated by number of fixations, duration, and visits, the greater the accuracy of the kick. Based on the study’s results, increased gaze coordination (focusing on a target external to the participant) increased the accuracy of the kick. Consistent with our hypothesis, this suggests that by focusing on a target before performing a penalty kick occupies a participant’s external cognitive pathway, creating a purer internal cognitive signal that allows for higher quality penalty kicks to result

How much traffic is too much? Finding the right vehicle quota for a scenic mountain road in the Italian Alps

An effective yet neglected option to limit the detrimental effects of car traffic in natural tourist destinations is the imposition of vehicle quotas. Defining the right quota for a road system, however, may not be straightforward because of the complex connection between the number of vehicles entering the system and traffic levels across space and over time. In this paper, we present a novel approach to tackle this issue that combines agent-based modeling and standards of quality, and we use it to define an hourly quota aimed at limiting traffic congestion and demand for parking along a scenic road in the Dolomites (Italian Alps). The model is designed and calibrated using geospatial and traffic data, and the acceptability of the quotas is further tested according to the hourly modal splits they might induce. Our model simulations highlight that, by redistributing morning traffic inflows, the quota can almost eliminate congestion with only a negligible impact on overall traffic figures. Further, while traffic reductions of up to 35% may be needed to eliminate traffic-related issues, more reasonable reductions (i.e. 10–25%) may be enough to address most of those. From an empirical perspective, the paper shows the effectiveness of quotas in sustainable transport and tourism; from a policy and management perspective, it proposes an approach for the definition of an ideal quota. The design of a quota system, however, requires detailed implementation and communication strategies, and more advanced simulation tools to capture circulation patterns induced by such strategies

Which affects affect the use of new technologies? Italian adaptation of the Internet Motive Questionnaire for Adolescents (IMQ-A) and criterion validity with problematic use and body dissatisfaction

Given the negative role of problematic use of new technological devices (NTD) in behavioral and psychological domains, the aim of the study is the Italian adaptation and validation of the Internet Motive Questionnaire for Adolescents (IMQ-A) in order to understand the motivation for the use of NTD. A total of 769 students 10-19 aged (M = 13.22, SD = 1.56) completed the IMQ-A, the Collins Figures Rating Scale, and two measures regarding the problematic NTD use, focused on overuse during the night and during meals. The IMQ-A showed adequate internal consistency with regard to its four subscales: Coping (α = .84), Social (α = .80), Enhancement (α = .80), and Conformity (α = .68) motives. However, with regard to factorial structure, a threefactor model (excluding Conformity subscale) showed slightly better fit indices than the original model. Coping motive was correlated with problematic NTD use and succeeded in predicting higher scores in body dissatisfaction as evidence of criterion-related and external validity. The Italian adaptation of the IMQ-A can be useful in both research and clinical fields, in order to propose alternative strategies for coping to users and to improve emotion regulation facets