New polytypes of long-period stacking ordered structures in a near-equilibrium Mg97Zn1Y2 alloy

By atomic-scale high-angle annular dark-field scanning transmission electron microscopy, the long-period stacking ordered (LPSO) structures in a near-equilibrium Mg₉₇Zn₁Y₂ (at.%) alloy have been characterised. In addition to 18R and 14H, new polytypes of LPSO structures are analysed and determined as 60R, 78R, 26H, 96R, 38H, 40H, 108H and 246R. All of these LPSO structures feature AB′C′A building blocks with two Mg layers and three Mg layers sandwiched between them. The Bravais lattices and space groups of new polytypes of LPSO structures were easily determined via the newly introduced method. A structural relationship between the LPSOs is proposed.     

Aesthetic value of paintings affects pain thresholds

Pain is modulated by cognitive factors, including attention and emotions. In this study we evaluated the distractive effect of aesthetic appreciation on subjectively rated pain (visual analogue scale;VAS) and multi-channel evoked potentials induced by CO₂ laser stimulation of the left hand in twelve healthy volunteers. Subjects were stimulated by laser in the absence of other external stimulation (baseline condition) and while looking at different paintings they had previously rated as beautiful, neutral or ugly. The view of paintings previously appreciated as beautiful produced lower pain scores and a clear inhibition of the P2 wave amplitude, localized in the anterior cingulate cortex; the inhibition of P2 wave amplitude was lesser or not significant during the presentation of the ugly or neutral paintings, respectively. Dipole source localization analysis of the LEP peaks showed significant changes during different conditions, with a shift from the posterior to the anterior right cingulated cortex while looking at paintings previously rated as beautiful.Our results provide evidence that pain may be modulated at cortical level by the aesthetic content of the distracting stimuli.     

‘I think a little bit of a kick is sometimes what you need’: Women’s accounts of whole-body scanning and likely impact on health-related behaviours

Objective: This study was designed to investigate whether whole-body scanning might promote healthy eating and physical activity in women, and to explore the effects of scanning on body image.

Design: Fourteen women aged 22–45 years without histories of eating disorders or whole-body scanning took part in semi-structured interviews before and after scanning. Data were analysed using inductive thematic analysis.

Results: Scans did not look as expected, and participants expressed ‘surprise’ and ‘shock’. Participants focused on perceived negative aspects of their bodies as revealed in scan images, and agreed that women with body concerns would find scans too ‘real’ and ‘raw’. Eleven women who met UK Government physical activity and healthy eating guidelines reported that the scan provided additional motivation to maintain, and in nine cases to increase, those behaviours. Two women who neither exercised nor ate healthily would not increase physical activity or change their diets significantly following scanning.

Conclusion: Whole-body scanning may enable maintenance or even acceleration of physical activity and healthy eating, but is unlikely to be useful in promoting initiation of these behaviours. Participants engaged in unhelpful body critique when viewing scans; scanning needs to be confined to contexts where support is provided, to avoid increasing body-related concerns.     

Formation of Ga–Pd–Sc icosahedral quasicrystal and approximant phases

ABSTRACT

We report the formation of an icosahedral quasicrystal and its approximant in the Ga–Pd–Sc alloy. The primitive-type quasicrystal with a six-dimensional lattice constant of 0.713?nm formed in the melt-quenched Ga₅₃Pd₃₀Sc₁₇ alloy, with a similar composition to that of the Ga₅₅Pd₃₀Sc₁₅ 1/1 approximant. The atomic-scale observation and chemical analysis of the 1/1 approximant by scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy showed that the approximant consisted of Tsai-type clusters with a characteristic chemical ordering. Furthermore, a series of approximants were observed in the Ga₅₅Pd₃₀RE₁₅ alloys by replacing Sc with other rare-earth elements (REs) (RE?= Y, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu). These approximants, which have relatively small lattice constants and consequently smaller RE–RE distances compared with those for other RE-containing Tsai-type approximants, may be candidates for materials with novel electronic and magnetic properties similar to those observed in Au-based quasicrystals and approximants.     

Influence of properties of layered silicate minerals on adsorbed DNA surface affinity,self-assembly and nanopatterning

We report on the specific interaction between DNA and some mica-family minerals and other layered silicate structures. The interaction depends on mineral surface's crystallography, chemistry and potential. These properties are responsible for a remarkable variety of adsorption mechanisms and can be used to modulate surface self-assembly and nanopatterning of DNA. The controlled deposition of DNA onto non-conductive mineral regions with atomically flat boundaries has very attractive applications in nano-biotechnology (for example, microelectronics, microarrays and sensors). In addition, the extreme affinity discovered for some mineral surfaces, together with their ability to organize the DNA molecules, could be an indication of their catalytic potential. It may also have had relevance in the prebiotic environment, with important implications for the earth and life sciences.     

Exploring early developmental changes in face scanning patterns during the perception of audiovisual mismatch of speech cues

Young infants are capable of integrating auditory and visual information and their speech perception can be influenced by visual cues, while 5-month-olds detect mismatch between mouth articulations and speech sounds. From 6 months of age, infants gradually shift their attention away from eyes and towards the mouth in articulating faces, potentially to benefit from intersensory redundancy of audiovisual (AV) cues. Using eye tracking, we investigated whether 6- to 9-month-olds showed a similar age-related increase of looking to the mouth, while observing congruent and/or redundant versus mismatched and non-redundant speech cues. Participants distinguished between congruent and incongruent AV cues as reflected by the amount of looking to the mouth. They showed an age-related increase in attention to the mouth, but only for non-redundant, mismatched AV speech cues. Our results highlight the role of intersensory redundancy and audiovisual mismatch mechanisms in facilitating the development of speech processing in infants under 12 months of age.     

表情信息特征变化对自闭症儿童面孔视觉扫描的影响

实验以眼动追踪技术为手段,考察自闭症儿童对不同信息特征表情图片的视觉扫描特征,探讨自闭症表情加工的机制。结果发现：1、看真人表情时,自闭症儿童对高兴、悲伤的整脸扫描时间无显著差异,均高于愤怒和恐惧,对愤怒的整脸扫描时间高于恐惧;2、看真人表情时自闭症儿童对高兴、悲伤表情的眼睛区域和嘴巴区域扫描时间无差异,对恐惧和愤怒的嘴巴区域扫描时间显著多于眼睛区域;3、信息特征削弱对自闭症儿童面孔表情视觉扫描产生了影响,随着削弱程度的增加,自闭症儿童对表情图片的嘴巴区域扫描时间增加,对眼睛区域的扫描时间减少。根据实验结果,认为自闭症儿童对表情的加工主要受到表情信息特征的影响,随着信息特征的变化,会对视觉注意进行调整,以获得对表情的充分加工。