Simultaneous factor analysis of dichotomous variables in several groups

A new method is proposed for a simultaneous factor analysis of dichotomous responses from several groups of individuals. The method makes it possible to compare factor loading pattern, factor variances and covariances, and factor means over groups. The method uses information from first and second order proportions and estimates the model by generalized least-squares. Hypotheses regarding different degrees of invariance over groups may be evaluated by a large-sample chi-square test.The research of the first author was supported partly by the Bank of Sweden Tercentenary Foundation under project Structural Equation Models in the Social Sciences, project director Karl G. Jöreskog, and partly by the Swedish Research Council in the Humanistic and Social Sciences under project Analysis of Contingency Tables, project director Bengt Muthén.     

Aging-related cocontraction effects during ankle strategy balance recovery following tether release in women

Increased antagonistic muscle activation during balance recovery has been documented during proprioceptive reliant responses in older adults. The authors examined ankle muscle cocontraction levels in young and older adults during balance recovery from a tether-release-induced, vestibular-input-reliant perturbation. Nine healthy young adult and 9 older women without history of falls performed maximum isometric plantar flexion and dorsiflexion trials followed by balance recovery trials using the ankle strategy. Surface electromyography data normalized to isometric conditions were analyzed during the 100 ms prior to release, the 50 ms immediately after release, and the 100-ms epochs from 100-400 ms following release. No differences existed in gastrocnemius and soleus activity levels (p > .05), though antagonistic tibialis anterior activity was greater in the older adults during the 300-400 ms epoch (young: 23.5 ± 5.8%, older: 38.7 ± 9.4%; p = .001). Vestibular-dominated perturbations may increase antagonistic activity during the recovery phase in older adults, inhibiting efficient balance recovery during proprioceptive and vestibular reliant perturbations.     

环境光照对情绪的影响及其作用机制

环境光照作为重要的授时因子, 对多种生理和心理功能存在广泛影响, 其对情绪的非视觉作用尤其引起研究者们的关注。研究发现, 环境光照的照度、色温和波长均是影响情绪的重要物理因素; 短光周期、夜间人工光以及持续光照/黑暗等异常光照模式则会导致情绪障碍; 光照的情绪效应还受到光照时长、时间点、个体特征、主观偏好及基因类型等的调节。光照作用于情绪的路径主要包括两个方面, 一方面视网膜中的内在光敏感神经节细胞将光信号投射至情绪调节相关脑区直接影响情绪; 另一方面光信号通过同步内部生理节律及其调节下的激素分泌、神经传递和睡眠间接影响情绪。未来研究考察短时光照的视觉功效时需要采用更客观多样化的情绪测量技术, 综合非视觉与视觉作用路径深入对比健康与情绪障碍群体的差异性。     

Highly fluorescent silver nanofluids with ferroelectric molecules

Highly fluorescent silver nanoparticles (Ag-NPs), soluble in a ferroelectric host of polymer molecules such as poly(vinylidene fluoride) (PVF₂), have been created in the form of nanofluids. The content of Ag-NPs (flocculates) is varied in steps 0.1–0.2 wt% up to a value of 5.0 wt% in tailoring a broad green emission band over 520–620 nm out of a hybrid percolation Ag–PVF₂ composite. A maximum intensity arises in this band at as small a percolation threshold as ～0.1 wt% Ag-NPs. It contains three distinct bands of peak values 541, 565, and 582 nm in an Ag-NPs tunable response of the localized surface plasmons. The emission-dependent anti-Stokes excitation spectrum contains a similar group of three bands 348, 401, and 421 nm. For Ag-contents above 0.1 wt%, interdependent intensities in the emission and excitation bands drop rapidly by as much as five times, conferring a metal–polymer percolation network. The results open wide applications for biological labels and light emitters using such nanofluids.     

强脉冲光子脱毛并发症的防治

为了探讨强脉冲光的脱毛疗效与并发症之间的关系,应用SpaTouchTM 强脉冲光脱毛仪去除体表多余毛发,一般需要3次～5次治疗,每次治疗间隔1个月～2个月,记录每例疗效及并发症发生的情况。结果显示,332例中434个部位接受治疗,患者均能耐受,无需麻醉,治疗后可正常工作及生活。有26个部位出现并发症,总发生率5.99%。10例治疗后出现红斑,15例出现水疱,1例出现色素沉着。末次治疗6个月后随访,422个部位治疗后毛发基本完全脱落,部分患者有少数细软毳毛再生,总有效率为97.24%。因此,强脉冲光脱毛效果可靠、操作简单、快捷、并发症少,是一种理想的脱毛方法。并发症发生原因主要是治疗时光斑能量过大,治疗前应进行测试,选择个体化光斑能量以减少并发症的发生。     

Effect of the light intensity upon the agonistic behaviour of juvenile of white‐seabream (Diplodus sargus cadenati de la Paz,Bauchot and Daget, 1974)

Ambient light levels were manipulated to vary potential predation risk, and aggressive behaviour was examined. Juveniles of white‐seabream (Diplodus sargus cadenati) interacted aggressively more frequently at intermediate light intensity (500 lux), being agonistic interactions at higher (3000 lux) or lower (5 lux) illumination less frequent. Aggr. Behav. 30:313–318, 2004. © 2004 Wiley‐Liss, Inc.     

Body language reading of emotion in schizophrenia: Associations with symptoms and functional outcome

Our aim was to explore how body language reading of emotion relates to neurocognition, symptoms and functional outcome in schizophrenia. Fifty‐four individuals with schizophrenia and eighty‐four healthy controls participated in the study. Emotion perception was assessed with a point‐light display (PLD) task, the Emotion in Biological Motion (EmoBio) test, neurocognition was measured with the MATRICS Consensus Cognitive Battery (MCCB), and functioning was indexed by one measure of functional capacity and by one self‐report questionnaire. Clinical symptoms were assessed with a five factor Positive and Negative Syndrome Scale (PANSS) symptoms model. Participants with schizophrenia had impaired body language reading of emotions compared to healthy controls (Cohen's d = 0.69). In participants with schizophrenia, emotion perception was associated with neurocognition (r = 0.42), functional capacity (r = 0.27) and disorganization symptoms (r = –0.27). Mediation analyses showed that disorganization symptoms mediated the effects of emotion perception and neurocognition, respectively, on social functional capacity. These results suggest that in individuals with schizophrenia, reduced emotion perception from body movements has negative consequences for functional outcome, but that the effect is mediated through disorganization symptoms.     

环境光照的认知功效及其调节因素与作用机理

自人类视网膜上发现存在新型的内在光敏感神经节细胞以来, 环境光照对个体生理心理功能的非视觉作用备受研究者青睐, 其中环境光照对认知功能的非视觉作用结果并不十分一致且内在机理尚不明确。环境光照的认知功效会受到光学参数、光照模式、时间因素、个体差异以及任务特征等的共同调节。未来的研究需要从环境光对心理认知功能的作用模式, 动态办公照明系统的开发, 面向特殊群体的个性化照明以及光照非视觉作用产生的分子生物学机制等视角进行扩展和深化。     

Does surrounding traffic benefit from an assisted driver with traffic light assistance system?

Traffic light assistance systems enable drivers more energy and time efficient driving behavior at signalized intersections. However, most vehicles will not be equipped with such systems in the next years. These unequipped vehicles’ drivers (UVDs) may benefit from assisted drivers, if they would adapt their behavior. This paper outlines how UVDs (N = 60) interpreted and reacted to a driver with traffic light assistance system. We used a multi-driver simulator with three drivers driving in a car-following scenario. The lead driver was not a participant, but a confederate who was followed by two UVDs. The confederate was apparently equipped either with or without a traffic light assistance system. The traffic light assistance system consisted of two functionalities: a Green Light Optimal Speed Advisory and a start-up assistance system with two different parametrizations. These functionalities aimed at preventing unnecessary changes in speed and reducing the start-up lost time after signal change. The results showed that UVDs benefited from the driving behavior of the confederate with traffic light assistance system. However, the assisted driving behavior was hardly understood and partly rated as aversive by the UVDs. We discuss how to enhance behavioral adaptation of UVDs. We also outline which negative consequences may result from encounters of driver with systems and UVDs. We assume that how UVDs react towards drivers with systems may be one factor contributing to a successful launch of such systems.     

The “Ages” of Ogden Nash

This essay looks at the way Ogden Nash, America's Genius of Light Verse, saw his life and times in the 30's, 40's, and 50's. It focuses on a group of poems in which the author mentions his age at the time of writing and explores their insights. They move from young adulthood to retirement and thus become Nash's equivalent of Shakespeare's Ages of Humanity. The author notes how his study of Nash has provided insights in living and illustrates this through poems of his own. In following this particular journey through the stages of life, we might well discover ways of mining the gold in our own experience.