Ultraviolet Spectra of Acetic Acid, Glycine, and Glyphosate

The influence of pH on the ultraviolet spectra of 0.001, 0.005, and 0.010 M glyphosate, glycine, and acetic acid was investigated. Each dilution of each acid was adjusted to acidic, neutral, and basic pH values. Ultraviolet spectra were recorded from 300 to 200 nm for each acid-dilution-pH combination. The wavelength of maximum absorption (Lambdamax) of glyphosate and glycine was slightly higher in the high pH solutions than in the neutral and low pH solutions. The Lambdamax of acetic acid was apparently unaffected by changes in ph. Molar extinction coefficients (epsilon) at Lambdamax increased with pH for all three acids. Regression analysis of the absorbance versus concentration for each acid-pH combination indicated linear relationships. Coefficients of determination (r2) were greater than 0.88 at both 210 and 215 nm for all acids and pH value

Quiet Eye research – Joan Vickers on target

In this target article (TA; CISS2016_100), Joan Vickers gives an overview of 20 years of research on her discovery that a relatively long lasting fixation before movement initiation enhances complex-motor performance, the so-called Quiet Eye (QE) phenomenon. Vickers’ main article (CISS2016_101) is the focus of sixteen peer commentaries (CISS2016_102 – CISS2016_117), authored by sport scientists with a special focus on the QE (Causer; Farrow & Panchuk; Klostermann, Vater & Kredel; Mann, Wright & Janelle; Schorer, Tirp & Rienhoff; Williams; Wilson, Wood & Vine), by sport scientists with different research foci (Baker & Wattie; Davids & Araujo; Frank & Schack; Helsen, Levin, Ziv & Davare; Rodrigues & Navarro), and by experts in human perception from disciplines beyond sport science (Foulsham; Gegenfurtner & Szulewski; Spering & Schütz; Watson & Enns). Finally, critiques, suggestions, and extensions brought forward by the commentators are acknowledged by Vickers in her closing response (CISS2016_118)

Creative actions in team sports are rooted in motor skills rather than in a divergent thinking ability

Creative actions are considered decisive in team sports. In most empirical studies on the topic so far, creativity has been understood as a player’s divergent thinking (DT) ability. Sport-specific DT has been assessed by the number, variety and originality of ideas a player is able to generate in response to game situations. Numerous studies indicate that DT can be improved with training. However, the fundamental assumption that enhanced DT transfers to creative on-field actions has yet to be examined. Alternatively, we argue that players’ potential to perform creative actions is foremost rooted in their motor-skill repertoire rather than in DT. In a field-based experiment, predictions deduced from both explanations were put to test. Elite youth football players participated in training interventions to enhance either football-specific DT (DT group) or their motor-skill repertoire (functional skills; FS group). Before and after the interventions, we assessed players’ football-specific DT as well as the functionality and creativity of actions performed on-field using expert ratings. As expected, in DT, the DT group improved more than the FS group. On the field, however, improvements in DT did not manifest in more creative actions. Rather, the FS group showed more pronounced improvements not only in the functionality but also in the creativity of on-field actions. This pattern of results challenges the so far predominant theoretical framework for creativity in sports. For sports practice, our findings suggest that on-field creativity is better fostered by enhancing players’ motor skills—and thus expanding their own action repertoire—than by improving DT

Time-Referenced Effects of an Internal vs. External Focus of Attention on Muscular Activity and Compensatory Variability

The paralysis-by-analysis phenomenon, i.e., attending to the execution of one's movement impairs performance, has gathered a lot of attention over recent years (see Wulf, 2007, for a review). Explanations of this phenomenon, e.g., the hypotheses of constrained action (Wulf et al., 2001) or of step-by-step execution (Masters, 1992; Beilock et al., 2002), however, do not refer to the level of underlying mechanisms on the level of sensorimotor control. For this purpose, a “nodal-point hypothesis” is presented here with the core assumption that skilled motor behavior is internally based on sensorimotor chains of nodal points, that attending to intermediate nodal points leads to a muscular re-freezing of the motor system at exactly and exclusively these points in time, and that this re-freezing is accompanied by the disruption of compensatory processes, resulting in an overall decrease of motor performance. Two experiments, on lever sequencing and basketball free throws, respectively, are reported that successfully tested these time-referenced predictions, i.e., showing that muscular activity is selectively increased and compensatory variability selectively decreased at movement-related nodal points if these points are in the focus of attention

Beyond task-space exploration: On the role of variance for motor control and learning.

This conceptual analysis on the role of variance for motor control and learning should be taken as a call to: (a) overcome the classic motor-action controversy by identifying converging lines and mutual synergies in the explanation of motor behavior phenomena, and (b) design more empirical research on low-level operational aspects of motor behavior rather than on high-level theoretical terms. Throughout the paper, claim (a) is exemplified by deploying the well-accepted task-space landscape metaphor. This approach provides an illustration not only of a dynamical sensorimotor system but also of a structure of internal forward models, as they are used in more cognitively rooted frameworks such as the theory of optimal feedback control. Claim (b) is put into practice by, mainly theoretically, substantiating a number of predictions for the role of variance in motor control and learning that can be derived from a convergent perspective. From this standpoint, it becomes obvious that variance is neither generally "good" nor generally "bad" for sensorimotor learning. Rather, the predictions derived suggest that specific forms of variance cause specific changes on permanent performance. In this endeavor, Newell's concept of task-space exploration is identified as a fundamental learning mechanism. Beyond, we highlight further predictions regarding the optimal use of variance for learning from a converging view. These predictions regard, on the one hand, additional learning mechanisms based on the task-space landscape metaphor-namely task-space formation, task-space differentiation and task-space (de-)composition-and, on the other hand, mechanisms of meta-learning that refer to handling noise as well as learning-to-learn and learning-to-adapt. Due to the character of a conceptual-analysis paper, we grant ourselves the right to be highly speculative on some issues. Thus, we would like readers to see our call mainly as an effort to stimulate both a meta-theoretical discussion on chances for convergence between classically separated lines of thought and, on an empirical level, future research on the role of variance in motor control and learning

Psychological issues in football officiating: An interview study with top-level referees

The present study aims on the identification of problems in the practice of top-level football refereeing. For this purpose, semi-structured interviews were conducted to collect data from 23 European elite referees. Through inductive content analysis, seven higher-order themes emerged: (1) descriptive, (2) characteristics of a good elite referee, (3) difficulties in decision-making, (4) pre-match preparation, (5) communication through headset, (6) decision-making, and (7) decision-making training. On the one hand, the findings underline the practical relevance of existing scientific research; on the other hand, the relevance of some areas of research, for instance, on the role of biases, is questioned by the interviewees’ statements. A particular need for further research could be revealed regarding the development, optimisation, or evaluation of (1) the pre-match preparation, (2) supporting technical devices, (3) innovative training tools for decision-making, (4) the within-team communication, and (5) complementary methods such as mental practice

2017 OFR demonstration site monitoring and analyses: Effects on soil hydrology and salinity, and potential implications on soil oxygen

On-farm recharge (OFR) is a practice that uses surface water to alleviate demand on and replenish groundwater supplies. It can take on two forms: in lieu recharge and direct recharge. In lieu recharge utilizes surface water supplies instead of groundwater to irrigate crops. Direct recharge applies water beyond the needs of the crop and replenishes the groundwater supply. ... The present study examined OFR with grapes, walnuts, and pistachios at six sites in the San Joaquin Valley, plus one additional site from a previous study, also in the San Joaquin Valley. Each site was comprised of a recharge plot that received direct recharge paired with a control plot with the same crop and soil characteristics, but meant to receive in lieu recharge (via the flood system) or drip application with groundwater. At the end of the 2017 recharge demonstration, however, three control plots had also received direct recharge from water applications that exceeded the crop’s water demand. At another site, both control and test plots had only received in lieu recharge due to limited surface water amounts or the host growers’ more conservative volume of water application. ... The present study only covers one season of recharge. Long-term effects of recharge are not described by the present study and will require further monitoring. Further study is needed of the dynamics of soil oxygen during and after recharge events. Similarly, the fate of the water after it infiltrates past the root zone is not always known and the rate at which recharged water will reach an aquifer is seldom known for deep aquifers. A method to predict the fate of water quickly and broadly would be quite helpful in developing an on-farm recharge strategy. The present study does not look at the effects of recharge on soil biological processes, such as microbial respiration and plant oxygen demand. Further study of the recharge tolerance of specific species and rootstocks, as well as the impact on plant disease, is crucial

Examining the functionality of peripheral vision: From fundamental understandings to applied sport science

In sports, it is important not only to locate gaze on the right location to utilize the high acuity of foveal vision, but also to attend to other objects in the environment without looking directly at them, accordingly, using peripheral vision. Peripheral vision becomes especially important if, for example, the processing of information from more than one location (e.g. players) is decisive in making accurate decisions. Since such decisions generally must be made under high spatio-temporal demands, costly eye-movements might be advantageously avoided by using peripheral vision for information pick-up from multiple cues. In a series of studies, we aimed to translate the demands found in sports and to investigate the functionality of peripheral vision in a well-controlled experimental paradigm, the multiple object tracking (MOT) task. MOT was implemented in a dual task, along with an additional event-detection task. The present article first presents an overview of sport-specific studies focusing on the functionality of peripheral vision and following, summarizes a series of three published MOT studies. These studies show that peripheral vision is used for simultaneous target monitoring and target-change detection and that visual and attentional demands affect gaze anchoring and change-detection rates. Results also reveal a dysfunctionality of saccades, and further suggest an event- and distance-optimized gaze-anchoring position. In the final portion of this article, we derive specific applications for future sports-specific research. Specifically, we suggest to: (a) use dual-task situations in sport-specific settings, such as monitoring multiple players in soccer and playing a pass at specific moments, (b) investigate the costs of saccades in sports situations with high spatio-temporal demands, as in martial arts, and finally, (c) manipulate attentional and visual demands. For each of these avenues of research, we sketch sports-specific experiments currently being conducted in our research group