On the nonrelation between spatial frequency and cerebral hemispheric competence

The hypothesis that the two cerebral hemispheres are specialized for processing different visual spatial frequencies is discussed in reference to Christman's (1989) review. It is suggested that the relevant results from every study reviewed by Christman which support the hypothesis can also be explained in terms of the total amount of visible information or energy contained in a visual stimulus, and the right hemisphere's relative resistance to information degradation. A recent study provides evidence in support of this total visible information/energy hypothesis, and appropriate measures of information/energy are discussed. Furthermore, results from the studies reviewed may reflect response bias and not hemispheric specialization or competence. The few studies which examine response bias support such an interpretation.     

Nucleation of recrystallization in fine-grained materials: an extension of the Bailey–Hirsch criterion

Abstract

A new criterion for nucleation in the case of dynamic recrystallization is proposed in order to include the contribution of the grain boundary energy stored in the microstructure in the energy balance. Due to the nucleation events, the total surface area of pre-existing grain boundaries decreases, leading to a nucleus size smaller than expected by conventional nucleation criteria. The new model provides a better prediction of the nucleus size during recrystallization of pure copper compared with the conventional nucleation criterion.     

On the plasticity event in metallic glass

Based on a systematic molecular dynamics analysis, this study reveals that plastic deformation of metallic glass is not through a uniform configuration change but via many localized plasticity events. These events are manifested by the atomic clusters of high kinetic energy and high strain rate, emerging even in the elastic deformation regime. The life of such a plasticity event is on the order of 10^?12?s, during which the distribution of kinetic energy follows a power law. The study shows that yielding in metallic glass occurs at the sudden surge point of the number of plasticity events. In the steady plastic deformation regime, the continuous nucleation and annihilation of the plastic events lead to a steady flow stress and stabilized total potential energy.     

Influence of body dissatisfaction on 1-year change in nutrient intake of overweight and obese inner-city African American children

This analysis aimed to examine the relationship of baseline body dissatisfaction with 1-year change in nutrient intake of inner-city, overweight and obese, African American children. This is a secondary analysis of 1-year pre-post data available for a convenience sample of 88 children. After adjusting for baseline intake of dietary variables and intervention group status, baseline body dissatisfaction was associated with 1-year increases in intake of energy, and all macronutrients in girls, but not in boys. These relationships were not substantially altered after adjusting for baseline BMIz and global self-worth. After including all adjustment factors, increasing baseline body dissatisfaction in girls was associated with 1-year increased intake of total energy, total sugars, total fat, discretionary fat, and total carbohydrates. This analysis suggests that, in girls but not necessarily in boys, body dissatisfaction might need to be targeted during interventions that aim to improve nutrient intake.     

Prediction of weightlifter’s motor behavior to evaluate snatch weightlifting techniques based on a new method of investigation of consumed energy

Using proper technique in different sports is an inevitable factor. In this study, available techniques for snatch weightlifting are mathematically evaluated. The optimal motion trajectory is a technique used by weightlifters, which could be determined based on minimizing specific object functions. Object functions based on total kinetic energy, total torque and total power and some new multiobjective functions are minimized using genetic algorithm and the minimax principle. Some important motion characteristics of 13 professional weightlifters were extracted and used to validate the mathematical results. The double knee bending (DKB) technique was studied as a benchmark test. Some important movement features of the technique were shown by the mathematical analysis when applying an object function, that minimized joint torques and powers of different muscles independently. An object function based on joint forces did not show these features.     

A relativistic Zeno effect

A Zenonian supertask involving an infinite number of identical colliding balls is generalized to include balls with different masses. Under the restriction that the total mass of all the balls is finite, classical mechanics leads to velocities that have no upper limit. Relativistic mechanics results in velocities bounded by that of light, but energy and momentum are not conserved, implying indeterminism. The notion that both determinism and the conservation laws might be salvaged via photon creation is shown to be flawed.     

Interpersonal and print nutrition communication for a Spanish-dominant Latino population: Secretos de la Buena Vida.

Participants (N=357) were randomly assigned to 1 of 3 conditions: lay health advisor (promotora) plus tailored print materials, tailored print materials only (tailored), or off-the-shelf print materials (control). The primary outcomes were calories from fat and daily grams of fiber. Secondary outcomes included total energy intake, total and saturated fat intake, and total carbohydrates. Adjusted for baseline values, calories from fat were 29%, 30%, and 30% for the promotora, tailored, and control conditions, respectively, and grams of fiber consumed were 16 g, 17 g, and 16 g. Significant Condition X Time interactions were not observed between baseline and 12-weeks postintervention. The LHA condition achieved significantly lower levels of energy intake, total fat and saturated fat, and total carbohydrates. The relative superiority of the promotora condition may derive from the personal touch achieved in the face-to-face interactions or from the women's use of print materials under the promotora's guidance.     

Binocular summation of equal-energy flashes of unequal duration

To determine if binocular summation occurs when increment flashes are of equal energy (Bloch’s law) but unequal in luminance-duration parameters, three Ss made temporal forced-choice judgments: (1) monocularly, (2) binocularly when the flashes to each eye were identical, (3) binocularly when the flashes to each eye were of equal energy but different in terms of their luminance and duration parameters, and (4) binocularly when flashes to each eye were separated by 100 msec. Binocular detection rates were consistently superior to monocular detection rates. Similarity in performance between Conditions 2 and 3 indicates that the binocular visual system responds only to the total energy of each monocular flash. The data from two Ss reveal that binocular performance was greater than that predicted on the basis of probability summation.     

Proactive Vitality Management and Creative Work Performance: The Role of Self-Insight and Social Support

Integrating proactivity and creativity literatures, we argue that people can perform more creatively at work when they proactively manage their levels of vitality. Proactive vitality management is defined as individual, goal-oriented behavior aimed at managing physical and mental energy to promote optimal functioning at work. We hypothesize that this process may be facilitated by being aware of one's own state and by support from others. A total of 242 employees participated in a weekly diary study for three consecutive weeks, yielding 610 observations. Results of multilevel analyses show that participants reported more creative work performance during weeks in which they had proactively used vitality management. In addition, in line with our predictions, self-insight and social support for creativity in the workplace acted as cross-level moderators and strengthened the relationship between proactive vitality management and creativity. We conclude that a proactive approach regarding physical and mental energy is an important bottom-up strategy that may foster creativity in work settings.     

An Energetic Comparison of Symmetrical and Asymmetrical Human Gait

This article contrasts the mechanical energy profiles of asymmetrical galloping with those of symmetrical running in adult humans. Seven female subjects were filmed while performing overground running and galloping at their preferred velocities. A previous study (Whitall & Caldwell, 1992) showed that kinematic differences between these gait modes included higher preferred velocity for running than galloping, with distinct differences in interlimb coordination but surprisingly similar intralimb patterns. Energetically, in the present study the whole body center of mass during galloping was found to behave much as it does in walking; kinetic and potential energy profiles were out of phase, as compared with running, which exhibited in-phase fluctuations of kinetic and potential energies. The primary reason for these center of mass differences was found in the energetics of the back leg of galloping, which demonstrated alterations in timing of its energy fluctuations and less energy generation than the front leg. Analysis of the power sources underlying the segmental energies during swing phase showed that the back leg's energy changes were accomplished mainly through reduced use of the hip muscles and less interlimb energy transfer. The back leg's energetics during swing also displayed a shift toward greater reliance on nonmuscular energy sources. A pattern of energy inflow during early swing and energy outflow during late swing was common to both running and galloping, although the galloping legs both demonstrated more abrupt transitions between these phases. The possibility is raised that the 67/33 interlimb phasing ratio used in galloping is selected to reduce mechanical energy variations of the total body center of mass. These data suggest that models of asymmetric gait in humans must account for more than merely phase alteration.     

Phase stability of Al3Nb as a function of nickel additions

Abstract

Phase stability of the intermetallic compound Al₃Nb is investigated as a function of nickel additions by band structure calculations based on an extended Hueckel tight-binding method. With this method, the electronic structure and total energies of the Al_6-n -Ni _n Nb₂ compounds (where n is an integer from 0 to 6) are calculated for both D0₂₂ and L1₂ structures under the assumption that nickel substitutes for aluminium. The electronic total energies obtained from integration of the energy states of all electrons considered have shown that the D0₂₂ structure is stable in the binary Al₃Nb compound as compared with the L1₂ structure; conversely, the L1₂ structure is stable for compounds with n values greater than 1. These calculations are in good agreement with X-ray diffraction results reported by Schubert and co-workers. Differences in the electronic total energy per atom between D0₂₂ and L1₂ are - 0·79 eV and 0·56 eV for n equal to 0 and 2, respectively.     

Coping with rising food costs in a closed economy: feeding behavior and nocturnal hypothermia in pigeons.

The pigeon's response to increasing fixed-ratio schedules in a 24-hr closed economy is marked by changes in feeding behavior during the daily light phase and by changes in body temperature during the dark phase. The time course of these responses to increasing behavioral cost of obtaining food is very different. Feeding is most affected immediately, within the first day of exposure to moderate fixed ratios. The number of times the pigeons produce the food hopper each day decreases, and the rate at which they eat from the food hopper (grams per minute) when it is available increases, as the fixed ratio is raised. Body temperature is affected later, falling to progressively lower resting levels during the dark phase as body weight drops at the higher fixed ratios when food intake is reduced. The changes in feeding and in body temperature that occur as the fixed-ratio schedule increases seem to reduce daily energy expenditures, within the constraints imposed by the experiment. The ascending and descending limbs of the bitonic function obtained when total daily operant responding is plotted as a function of fixed-ratio schedule in the closed economy is possibly related to the occurrence of thermoregulatory strategies for energy conservation. The energetic analysis of performances in the closed economy requires consideration of a variety of energetic strategies available to the species being studied.     

Relaxation of the elastic strain energy of misfitting inclusions due to diffusion of vacancies

Vacancy diffusion is investigated as a mechanism for relaxation of the elastic strain energy caused by a misfitting inclusion. The kinetics of reduction of the total eigenstrain by the deposition or removal of an atom layer along the interface is derived. The time evolution, as well as an estimate for the characteristic time of the relaxation process, is presented. The relaxation times are compared with recent in situ measurements of stress relaxation times in aluminum with small lead-alloy inclusions after their solidification. Experimentally observed relaxation times and those theoretically predicted agree very well.     

The effects of acute stress and pubertal development on metabolic hormones in the rat

A dramatic change in stress responsiveness occurs during pubertal development such that stress-induced corticosterone secretion in prepubertal animals takes 45-60 min longer to return to baseline compared to adults. Though corticosterone is known to influence energy mobilization, it is presently unknown whether stressors affect other hormones important in energy utilization and metabolism differentially in animals before and after pubertal development. Therefore, we exposed prepubertal (28 days of age) and adult (77 days of age) male rats to a single 30 min session of restraint stress in either the light or dark phase of the animals' light-dark (LD) cycle and measured plasma glucose, insulin and thyroid hormones (thyroxine (T4) and triiodothyronine (T3)). We found similar stress-induced increases in plasma glucose levels in prepubertal and adult animals in the LD phase of the LD cycle. We also found that prepubertal animals have lower circulating insulin and total and free T4 levels, but higher total and free T3 levels compared to adults in both the light and dark phases (LD). Interestingly, insulin and thyroid hormone levels were unaffected by acute stress at either age or time of day. These data indicate that, despite prepubertal animals showing an extended glucocorticoid stress response after a single acute exposure to stress, glucose levels are similarly affected by acute stress in prepubertal and adult animals. Furthermore, though stage of development significantly affects the levels of peripheral metabolic hormones such as insulin, T4 and T3, acute stress does not appreciably influence their secretion before or after puberty.     

An alternative view of the concept of utilisation of elastic energy in human movement

It is widely accepted that the series elastic component (SEC) of muscles and tendons plays an important role in dynamic human movements. Many experiments seem to show that during a pre-stretch movement energy can be stored in the SEC which is re-used during the subsequent concentric contraction. Mechanical calculations were performed to calculate the capacity for muscles and tendons to store elastic energy. The storage of elastic energy in muscle tissue appears to be negligible. In tendons some energy can be stored but the total elastic capacity of the tendons of the lower extremities appears far too small to explain reported advantages of a pre-stretch during jumping and running.Based on literature concerning chemical change and enthalpy production during experiments on isolated muscles, a model is proposed which can explain the advantages of a preliminary counter movement on force and work output during the subsequent concentric contraction. The main advantage of a pre-stretch, as seen in movements like jumping, throwing and running, seems to be to prevent a waste of cross bridges at the onset of a contraction in taking up the slack of the muscle. The model can explain why the mechanical efficiency in running can be much higher than in cycling. A muscle which is stretched prior to concentric contraction can do more work at the same metabolic cost when compared with a concentric contraction without pre-stretch.     

From sport to eco: A case study of driver inputs on electric vehicle efficiency

This study focuses on driver-induced changes to vehicle energy and emissions performance by altering drivetrain configurations. It defines and examines the motivations for the use of drive modes in plug-in hybrid electric vehicles (PHEVs). Drive modes are defined as user-selectable drivetrain configurations that allow drivers to change vehicle performance aspects such as altering its propulsion status from electric to gas, changing the steering responsiveness, suspension stiffness, and regenerative braking strength. Despite the direct impact they have on the vehicle’s energy usage, greenhouse gas emissions, and local air emissions, the impact of drive modes are not traditionally measured as part of the vehicle’s performance and certification tests. The impact of drive mode choice can explain a portion of the discrepancy between PHEVs expected and on road performance as a recent study by the authors found that the use of certain modes can result in a 15–30% increase in total energy usage in a vehicle traveling at freeway speeds.This is the first study to examine the motivations for the use of these drive modes and provides an overview of PHEV drive modes, classifying them into two main mode categories (propulsion adjustment and driver experience) and eight different mode types based on their intended purpose. This is followed by a logistic regression of 11 indicators for mode usage taken from a survey of over 4,500 PHEV owning households, showing that gender and the number of long-distance trips were the most commonly associated with usage across mode types.     

A Case of Obsessive-Compulsive Disorder

This article presents the case of a 51-year old woman with obsessive-compulsive disorder. “Caroline” reported obsessions of harming people secondary to spreading her “bad energy,” which is experienced as dust on her hands and in her mouth. To prevent harm coming to others she mentally “vacuums” the dust, creates mental protective barriers around nearby people and avoids touching others for fear of transmitting her bad energy. Although she reported a childhood onset of obsessions and compulsions, it exacerbated in the context of multiple stressors 4 years prior to seeking treatment. Her Yale-Brown Obsessive Compulsive Scale total score was in the moderate range at intake. Predisposing, precipitating, and maintaining factors are described in addition to the specific symptom presentation.     

Health and salvation as the ethical ideal

Health and salvation are related terms, because each seeks the well-being of the whole person. When placed within the Judeo-Christian context, health as salvation can be defined as the highest good for the total human community. This good is denied to humanity through the unequal use of the world's resources, a fact underscored by the current energy crisis. Two questions must be answered: 1) Do we possess the scientific means to rectify this ethically unacceptable situation? 2) Do we desire to implement the necessary steps to change, should they be found?     

Stress, Energy, and Immunity: An Ecological View

ABSTRACT— A common perspective on stress-related changes in the human immune system is that such changes are potentially harmful, especially those occurring during chronic stress. In contrast, an ecological perspective views the immune system as an energetically costly system that may or may not have priority over other uses of that energy. From this perspective, the immune system may have energy made available for it via reduction of other activities, may change in energetically conservative ways when the protection it confers needs to be balanced with the energetic demands of other activities such as fight or flight, or may be suppressed when other activities are more important than immunity for total well-being. This last type of change can explain why aspects of psychosocial health such as optimism relate to worse immunity under some circumstances and suggests that both benefits and costs of immunosuppression during stress should be considered in research on human stress and immunity.     

Linear systems analysis of infant visual pattern preferences

Karmel's check-pattern preference data for 13-week-old infants were reanalyzed using linear systems analysis. The two-dimensional Fourier amplitude spectrum was calculated for each of his eight checkerboard and random check patterns. The mean contrast sensitivity data for 3-month-old infants of Banks and Salapatek and the spatial frequency amplitudes of the patterns were used to derive three metrics to predict the looking times observed by Karmel. One was based on the sensitivity of the visual system to the single pattern component highest above threshold (maximum amplitude), the second was based on the total amount of pattern energy above threshold (total summation), and the third was based on the maximum amplitude with summation over nearby spatial frequency components (limited summation). The predictive power of the maximum amplitude and the total summation metrics depended on whether the pattern type was checkerboard or random check. The limited summation metric predicted looking times well for both pattern types. A linear function of the logarithm of the limited summation metric accounted for 91% of the total variance in looking time.