Do knee concentric and eccentric strength and sagittal-plane knee joint biomechanics differ between jumpers and non-jumpers in landing?

The purpose of this study was to investigate the differences of knee concentric and eccentric strength and impact related knee biomechanics between jumpers and non-jumpers during step-off landing tasks. Ten male college swimming athletes (non-jumpers) and 10 track and volleyball athletes (jumpers) were recruited to participate in two test sessions: a muscle strength testing session of concentric and eccentric extension for dominant knee joint at 60 °/s and 180 °/s and a landing testing session. The participants performed five trials of step-off landing in each of four conditions: soft and stiff landing from 0.4 m and 0.6 m landing heights. The three-dimensional kinematics and ground reaction force were recorded simultaneously during step-off landing conditions. The results showed that the jumpers had significantly greater peak knee eccentric extension and concentric flexion torques compared to the non-jumpers. No significant group effects were found for peak vertical ground reaction force and knee range of motion during landing. The jumpers had significantly greater knee contact flexion angle, maximum knee flexion angle and initial knee extension moment compared to the non-jumpers. These results suggest that these athletes adopted a favorable impact attenuation strategy that is related to the greater knee eccentric muscle strength and training.     

Resilience and affect balance as mediators between trait emotional intelligence and life satisfaction

The current study aimed to analyze the importance of trait emotional intelligence in life satisfaction and to extend the previous literature by investigating the potential mediating effects of resilience and affect balance in this relationship. To test the study hypotheses, self-report measures of trait emotional intelligence, resilience, positive and negative affect, and life satisfaction were administrated to 263 undergraduates. Correlation analysis indicated that trait emotional intelligence was positively correlated with life satisfaction. Mediational analyses showed that trait emotional intelligence exerted its indirect effect on life satisfaction through the simple mediating effect of affect balance and the three-path mediating effect of resilience–affect balance. In addition, resilience played as a partial mediator between trait emotional intelligence and affect balance. Furthermore, multi-group analyses showed that the mediational model was not moderated by gender. Therefore, this study makes a contribution to the complex nature of the association between trait emotional intelligence and subjective well-being.     

Learning and Affect Following Near‐Miss Outcomes in Simulated Gambling

Gambling near‐misses are non‐rewarded events that resemble a winning configuration. Past research using slot machines has shown that moderate rates of near‐misses increase gambling persistence, but the mechanisms supporting this persistence are unclear. One hypothesis is that near‐misses are mistakenly interpreted as signals of skill acquisition, supporting learning and fuelling the ‘illusion of control’. A slot machine simulation was administered to 60 volunteers, with ratings of the perceived chances of winning, pleasure and motivation to play following particular outcomes. Psychophysiological measures (electrodermal activity and heart rate) were taken, and gambling persistence was measured after 30 trials. Near‐misses were similar to full‐miss outcomes in that they were regarded as unpleasant. However, near‐misses were akin to win outcomes in that they increased motivations to play and electrodermal activity. Learning was evidenced by the expectancy of winning increasing following wins and decreasing after losses. Although there was no overall change in expectancy of winning after near‐misses across all participants, those subjects reporting a greater increase in the expectancy of winning following a near‐miss showed more persistent play, consistent with the learning hypothesis. Greater heart rate acceleration following near‐misses was also associated with persistence. We also observed differential effects of near‐misses where the reel stopped either side of the winning position (‘payline’): motivational effects were restricted to near‐misses stopping before the payline, whereas near‐misses that stopped after the payline were primarily aversive. The payline effects are not predicted by the learning hypothesis and may indicate an affective component to near‐misses, possibly linked to counterfactual processing. Copyright © 2012 John Wiley & Sons, Ltd.     

Evaluating Word in Phrase: The Modulation Effect of Emotional Context on Word Comprehension

The present study aims to explore the influence of emotional context on word evaluation. Participants were asked to read an “adjective + noun” phrase, where the adjective could be a positive or negative word, and the noun could be a positive, neutral or negative word, and then to make an emotional evaluation on the emotional tone of the target noun based on a 9-point Likert scale. In a control condition, an isolated noun was presented with no context. Results showed that positive context made the evaluation of target words bias toward positive tone, while negative context shaped the evaluation of target words toward negative tone. The modulatory effect of negative context was greater than that of positive context in shaping evaluation of emotional words with opposite valence. Moreover, the modulatory effect of emotional context was constrained by the inherent meaning of target word. The present study demonstrated the flexibility as well as the relative stability of emotional meaning of word.     

环境雌激素双酚A对成年小鼠学习记忆和突触结构的影响*

双酚A (bisphenol, BPA)是一种广泛存在的环境内分泌干扰物,它可与雌激素受体结合干扰内源性雌激素对中枢神经系统的调控作用。本研究通过将10周龄小鼠灌胃染毒BPA (0.4、4、40 mg/kg/day)3个月,研究长期BPA暴露对成年小鼠记忆行为和突触可塑性的影响。开场行为测试结果表明, BPA (0.4、4、40 mg/kg/day)增加雄性的站立次数和理毛频率, BPA (4 mg/kg/day)却显著减少雌鼠的站立次数。水迷宫和被动回避行为模型检测显示, BPA主要损伤雄鼠的空间学习记忆和被动回避记忆。通过制备海马CA1区超薄切片后,电镜观测发现, BPA (0.4、40 mg/kg/day)暴露降低雄鼠海马CA1区突触数密度,缩短雄鼠突触前活性带长度,减小雄鼠突触后致密体(PSD)厚度,增加雄鼠突触间隙宽度。进一步用Western blot方法检测突触前、后的标志性蛋白Synapsin I和PSD95以及兴奋性氨基酸NMDA受体NR1亚基和AMPA受体GluR1亚基蛋白的表达,发现BPA暴露致雄鼠Synapsin I、PSD95、NR1蛋白表达水平下调。而BPA对雌鼠的记忆行为、突触形态、突触蛋白和受体蛋白均没有明显作用。以上结果提示长期B PA暴露性别特异性地影响成年小鼠的活动性和探究行为,损伤雄鼠的学习记忆,这些作用可能通过下调突触蛋白和NMDA受体的表达而负性影响突触结构可塑性,最终影响雄鼠的学习记忆功能。     

Gender Differences in Attitudes Toward Women as Sales Managers in the People's Republic of China

The present study promulgates a research stream in the area of understanding women's position in the management of the Chinese sales force. The study investigates attitudes toward women as sales managers held by Chinese salespeople. Male salespeople consistently rated the female sales managers lower than did female salespeople on three sets of attitude items. This finding indicates the presence of male resistance to women in sales management positions.     

The Relationship Between Blood Lead,Bone Lead and Child Intelligence

We report associations between serial measures of blood lead and intelligence in children age 10–12 years, half heavily exposed to lead from the prenatal period onward, and half relatively unexposed. For a subsample, we examine bone lead-IQ associations, comparing them with blood lead associations. Both blood and bone lead levels were associated with intelligence decrements, small relative to the contribution of social factors. For each doubling of Tib-Pb, Full Scale, Performance, and Verbal IQ decreased by an estimated 5.5, 6.2, and 4.1 points, respectively. Bone lead-IQ associations were stronger than those for blood lead, which nonetheless provide robust analogues. Current BPb, easy to obtain, provides a useful means for assessing Pb exposure/IQ associations.     

High-pressure phase transition and lattice dynamics of rock-salt and FeSi-type phases of MgS

A phase transition of MgS under high pressure is investigated using a first-principles method. It is found from energy-volume calculations that the rock-salt (B1) phase of MgS transforms into a FeSi-type (B28) phase at 143?GPa. The calculated ground-state parameters in the B1 phase are in excellent agreement with available experimental and theoretical data. Ab initio phonon calculations are also performed to investigate the structural behaviour of MgS under high pressure. An unstable transverse acoustic mode and a phase transition from B1 to B28 phase at ~143.7?GPa driven by this soft mode are predicted. The B28 structure of MgS is stable up to 350?GPa according to lattice dynamics calculations.     

Electrical conductivity of Nd and Ce co-doped Gd2Zr2O7 ceramics

In this study, (Gd_{1? x} Nd _x )₂(Zr_{1? x} Ce _x )₂O₇ (0 ≤ x ≤ 0.5) ceramics have been prepared by pressureless sintering at 1973 K to investigate the influence of Nd and Ce co-doping on their electrical conductivity. The electrical conductivity of the ceramics was investigated by impedance spectroscopy measurements from 723 to 1173 K over the frequency range of 20 Hz to 2 MHz in air. The measured values obey the Arrhenius relation. For each composition, the grain conductivity gradually increases with increasing temperature from 723 to 1173 K. At a given temperature, it gradually decreases with increasing neodymium and cerium contents from x = 0 to 0.3; thereafter, the grain conductivity exhibits a slight increase with further increasing neodymium and cerium contents up to x = 0.5.     

High-temperature creep associated with the climb of extended dislocations subjected to chemical stresses

The effect of chemical stresses upon the relation between extended dislocations and high-temperature creep in a thin plate has been investigated. The critical stress needed for the contraction of extended jogs and its effect on the creep rate are obtained. The results indicate that the critical stress needed for the contraction increases with decreasing stacking fault energy (SFE). However, creep occurs more easily with increasing SFE and increasing angle of the Burgers vector to the dislocation line, as well as with the concentration of any diffusing atoms.