The Fano plane as an octonionic multiplication table

This paper analyzes the use of the Fano plane as the octonionic multiplication table. In particular, we count the number of nonequivalent ways the Fano plane can be labeled as the octonionic multiplication table, arguing that 28 such labelings exist

A biomechanical and physiological comparison of deep-water running styles

Purpose: The purpose of this investigation was to identify a deep-water running (DWR) style that most closely approximates terrestrial running. Methods: Twenty healthy male and female intercollegiate (NCAA III) distance runners were videotaped from the right sagittal view while running on a treadmill (TR) and in deep water at 55-60% of their TR VO₂[subscript max] using each of four DWR styles: shod cross-country (SCC), barefoot cross-country (BCC), shod high-knee (SHK), and barefoot high-knee (BHK). All biomechanical data were digitized and analyzed using the Peak Motus® system. Physiological variables of interest were oxygen consumption (V0₂), heart rate (HR), and rating of perceived exertion (RPE). Biomechanical variables of interest were horizontal (X) and vertical (Y) displacement of the knee and ankle, and stride rate (SR). An ANOVA with repeated measures was utilized to ascertain the differences across styles. The alpha significance level was set at .05, and a post hoc pairwise analysis was conducted with a Bonferonni adjustment of the alpha level. Results: Omnibus significant differences were found for all physiological variables: VO₂ (p<.025), HR (p<.042), RPE (p<.000). However, the post hoc pairwise comparisons revealed that only TR vs. SHK V0₂ (p<.005), and the RPE responses for treadmill vs. all DWR styles exhibited significant differences (p<.000-.002). Omnibus tests for biomechanical variables exhibited statistical significance. The post hoc pairwise comparisons revealed significant differences in SR (p<.000) between TR (1.25 ± .08 Hz) and all DWR styles and also between the CC and HK styles of DWR (SCC: 0.78 ± .08 Hz, BCC: 0.81 ± .08 Hz, SHK: 1.13 ± .10 Hz, BHK: 1.14 ± .10 Hz). The CC style of DWR was found to be similar to TR with respect to linear ankle displacement, whereas the HK style was significantly different from TR in all but two of the 16 comparisons made for ankle and knee displacement. Conclusion: The CC style of DWR is recommended as an adjunct to distance running training if the goal is to mimic the ankle linear horizontal displacement of land-based running. However, if the goal is to mimic SR, the HK style is a closer approximation than the CC style

The effect of surface type on plantar pressure distribution and running kinematics

The purpose of this study was to examine pressure at five selected sites on the plantar surface of the foot and adaptations in running kinematics among fourteen male varsity collegiate distance runners on five different surfaces--asphalt, cinders, concrete, grass, and tartan. Pressure data were collected with an Electrodynogram system (EDG) and kinematic data were collected with a Redlake LOCAM 16mm high-speed camera operating at 100 fps. Repeated measures ANOVA was utilized to evaluate differences (p<0.10) among the variables. Pressure at the fifth metatarsal site on the left foot was found to be higher on the harder surfaces--asphalt, concrete, and tartan--than on the softer surfaces--grass and cinders. Higher pressures were found, in general, on the metatarsal region of the foot as opposed to the calcaneal region, especially while running on the harder surfaces. This finding may suggest that adequate shock absorption occurs in the calcaneal region of the shoe used in this study, and/or the metatarsal region of the foot-shoe interface may merit more attention than is commonly thought. This contention is substantiated by the research of Cavanagh & LaFortune (1980). Among the kinematic variables quantified--stride length, stride rate, single leg support time, and swing time--only stride rate varied with surfaces. Stride rate was found to be slightly, but significantly (p<0.10) slower on concrete and asphalt than on the softer surfaces. The differences observed may be representative of a tendency of runners to slow down on concrete and therefore attenuate as much force as possible. This contention is substantiated by the research of Feehery (1986) and Nigg (1985). The other three kinematic variables were relatively unaffected by differences in the running surfaces investigated. The results of this study indicate that the underlying mechanisms and adaptations to running on different surface types are extremely complex phenomena which merit further investigation before physical educators and coaches can be provided with firm guidelines for appropriate running surface(s) for students and athletes

Effects of hydrogen on 4130 steel microstructure during tensile loading

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Facial emotion recognition and sleep in mentally disordered patients: A natural experiment in a high security hospital

We investigated the relationship between a change in sleep quality and facial emotion recognition accuracy in a group of mentally-disordered inpatients at a secure forensic psychiatric unit. Patients whose sleep improved over time also showed improved facial emotion recognition while patients who showed no sleep improvement showed no change in emotion recognition

Clostridium difficile in Retail Meat Products, USA, 2007

To determine the presence of Clostridium difficile, we sampled cooked and uncooked meat products sold in Tucson, Arizona. Forty-two percent contained toxigenic C. difficile strains (either ribotype 078/toxinotype V [73%] or 027/toxinotype III [NAP1 or NAP1-related; 27%]). These findings indicate that food products may play a role in interspecies C. difficile transmission

Influence of river discharge on grass carp occupancy dynamics in south‐eastern Iowa rivers

Despite the longstanding presence of grass carp Ctenopharyngodon idella in the Upper Mississippi River (UMR) watershed, information regarding their populations remains largely unknown, in part because capture is difficult. Occupancy models are a popular wildlife assessment tool to account for imperfect detections but have been slow to be adopted in fisheries. Herein, we used occupancy modelling to evaluate the influence of two environmental covariates (river discharge and water temperature) on grass carp occupancy, extinction, colonization, and detection at nine sites within south‐eastern Iowa rivers from April to October 2014 and 2015. Grass carp were detected at least once at all but one site. The most parsimonious model indicated that grass carp colonization probability increased from 0.15 to 0.67 with increases in river discharge. In contrast, occupancy (0.20), extinction (0.29), and detection (0.50) probabilities were temporally constant. Models indicated that water temperatures did not influence grass carp extinction or colonization probabilities relative to river discharge. Cumulative grass carp detection probability approached 1.0, whereas conditional occupancy estimates were less than 0.1 when using five or more sampling transects. The use of a robust design occupancy model allowed us to estimate site occupancy rates of grass carp corrected for imperfect detections, while demonstrating the importance of river discharge for site colonization. These results can be used to assess the distribution of a cryptic fish while helping to guide grass carp sampling and removal efforts

Gender and Weight Shape Brain Dynamics during Food Viewing

Hemodynamic imaging results have associated both gender and body weight to variation in brain responses to food-related information. However, the spatio-temporal brain dynamics of gender-related and weight-wise modulations in food discrimination still remain to be elucidated. We analyzed visual evoked potentials (VEPs) while normal-weighted men (n = 12) and women (n = 12) categorized photographs of energy-dense foods and non-food kitchen utensils. VEP analyses showed that food categorization is influenced by gender as early as 170 ms after image onset. Moreover, the female VEP pattern to food categorization co-varied with participants' body weight. Estimations of the neural generator activity over the time interval of VEP modulations (i.e. by means of a distributed linear inverse solution [LAURA]) revealed alterations in prefrontal and temporo-parietal source activity as a function of image category and participants' gender. However, only neural source activity for female responses during food viewing was negatively correlated with body-mass index (BMI) over the respective time interval. Women showed decreased neural source activity particularly in ventral prefrontal brain regions when viewing food, but not non-food objects, while no such associations were apparent in male responses to food and non-food viewing. Our study thus indicates that gender influences are already apparent during initial stages of food-related object categorization, with small variations in body weight modulating electrophysiological responses especially in women and in brain areas implicated in food reward valuation and intake control. These findings extend recent reports on prefrontal reward and control circuit responsiveness to food cues and the potential role of this reactivity pattern in the susceptibility to weight gain

Food color is in the eye of the beholder: the role of human trichromatic vision in food evaluation

Non-human primates evaluate food quality based on brightness of red and green shades of color, with red signaling higher energy or greater protein content in fruits and leafs. Despite the strong association between food and other sensory modalities, humans, too, estimate critical food features, such as calorie content, from vision. Previous research primarily focused on the effects of color on taste/flavor identification and intensity judgments. However, whether evaluation of perceived calorie content and arousal in humans are biased by color has received comparatively less attention. In this study we showed that color content of food images predicts arousal and perceived calorie content reported when viewing food even when confounding variables were controlled for. Specifically, arousal positively co-varied with red-brightness, while green-brightness was negatively associated with arousal and perceived calorie content. This result holds for a large array of food comprising of natural food - where color likely predicts calorie content - and of transformed food where, instead, color is poorly diagnostic of energy content. Importantly, this pattern does not emerged with nonfood items. We conclude that in humans visual inspection of food is central to its evaluation and seems to partially engage the same basic system as non-human primates