Dislocation evolution in twins of cyclically deformed copper

The evolution of dislocation structure in twins of different thicknesses has been investigated in polycrystalline copper fatigued at room temperature under constant plastic axial strain amplitude control. The dislocation structure and its evolution strongly depend on twin thickness. Three critical thicknesses must be distinguished, i.e. (i) characteristic size of fatigue dislocation structures, about 1?µm; (ii) critical height of stable dislocation wall structure, about 200?nm; (iii) critical spacing of dislocation dipole, about 20?nm. It is considered that the size effect is mainly caused by twin boundaries (TBs) which play different roles on slip behaviors in twins.     

Local translational order in the icosahedral quasicrystalline phase of V41Ni36Si23

Abstract

The local translational order of the icosahedral quasicrystalline phase in rapidly solidified V₄₁Ni₃₆Si₂₃ has been investigated by means of selected-area electron diffraction and high-resolution electron microscopy. Experimental results show that translational order always occurs in the twofold direction and can be observed when the quasicrystal is examined along its fivefold and threefold as well as twofold axes. Sometimes it occurs in two or three coplanar twofold directions simultaneously. In these cases some crystalline islands exist in the icosahedral quasicrystal and this corresponds to the initial stage of transformation from a quasicrystal to the stable crystalline phase.     

辅助上肢康复训练与自助Bobath握手训练对卒中患者的对比观察

观察由护士辅助上肢运动能力康复训练与患者自助Bobath握手上举训练对脑卒中偏瘫患者上肢功能恢复的影响。将60名患者随机分为对照组和试验组,对照组患者自助做Bobath握手上举训练,试验组由护士给予上肢运动能力分期康复训练。1个月后,两组患者上肢功能差异及日常生活活动（activities of daily living,ADL）能力差异有统计学意义（P〈0．05）。1个月后,两侧肩峰差差异也有非常显著的统计学意义（P〈O．01）。因此,由护士给予上肢运动能力分期康复训练有利于脑卒中偏瘫患者提高上肢功能和日常生活活动能力,以及保持正常的人体姿势利于患者康复。     

From STEM to STEAM: Cracking the Code? How Creativity & Motivation Interacts with Inquiry-based Learning

STEM subjects enriched with Arts (STEAM) are assumed to enhance science lessons and making them more attractive. A multidisciplinary STEAM module integrating inquiry-based learning was implemented to a sample of 160 students (11–12 years; 43.1% females). In a four-hour lesson, dealing with scientific phenomena surrounding bird flight, students learned at self-explanatory workstations that allowed space for creativity and a high level of autonomy. An arts facet was employed, using collaborative handicraft artwork. A workbook offered guidance, while the teacher’s role was of a passive tutor. A pre-/post-/retention-test design monitored knowledge, motivation, and two factors associated with creativity (Act and Flow) two weeks before, immediately after and six weeks later. The intervention produced long-term knowledge and built stable scores of intrinsic motivation, but self-reported aspects of creativity were not affected with a single STEAM intervention. Thus, it seems obvious that regular training in an adequate sociocultural setting is needed to develop creativity sustainably. Nevertheless, this study monitored the correlation of knowledge motivation and creativity in a science education setting for the first time. The findings indicate that fostering creativity, for example in STEAM environments, is a promising starting point for research into promoting motivation and creativity in educational settings.     

Visual attention and manual response selection: Distinct mechanisms operating on the same codes

In four experiments, participants made a speeded manual response to a tone and concurrently selected a cued visual target from a masked display for later unspeeded report. In contrast toaprevious study of H.Pashler (1991), systematic interactions between the two tasks were obtained. First, accuracy in both tasks decreased with decreasing stimulus (tone-display)-onset asynchrony (SOA)— presumably due to a conflict between stimulus and response coding. Second, spatial correspondence between manual response and visual target produced better performance in the visual task and, with short SOAs, in the tone task, too— presumably due to the overlap of the spatial codes used by stimulus- and response-selection processes. Third, manual responding slowed down with increasing SOA — reflecting either a functional bottleneck or strategic queuing of target selection and response selection. Results suggest that visual stimulus selection and manual response selection are distinct mechanisms that operate on common representations.     

A glimpse is not a glimpse: Differential processing of flashed scene previews leads to differential target search benefits

The question of whether words can be identified without spatial attention has been a topic of considerable interest over the last five and a half decades, but the literature has yielded mixed conclusions. The present experiments manipulated the proportion of valid trials (the proportion of trials in which a cue appeared in the same location as the upcoming target word) so as to encourage distributed (50% valid cues; Experiments 1 and 3) or focused (100% valid cues; Experiments 2 and 4) spatial attention in a priming-type paradigm. Participants read aloud a target word, and the impact of a simultaneously presented distractor word was assessed. Semantic and orthographic priming effects were present when conditions promoted distributed spatial attention but absent when conditions promoted focused spatial attention. In contrast, Experiment 5 yielded a distractor word effect in the 100% valid cue condition when subjects identified a colour (Stroop task). We take these results to suggest that (1) spatial attention is a necessary preliminary to visual word recognition and (2) examining the role of spatial attention in the context of the Stroop task may have few implications for basic processes in reading because colour processing makes fewer demands on spatial attention than does visual word recognition.     

Educated and Happy: A Four-Year Study Explaining the Links Between Education,Job Fit,and Life Satisfaction

Drawing on a bottom-up theoretical perspective on life satisfaction, we developed and tested a model that specifies distinct paths from education to life satisfaction through three domain satisfactions (i.e., job, financial, and health satisfactions). Furthermore, we proposed explanatory mechanisms for each of these three paths (i.e., job fit, financial literacy, and proactive healthy behaviours). To test our hypotheses, we used a large probability sample comprising 3,011–9,669 individuals, from the Netherlands, who provided survey responses over four consecutive years. The results supported the hypothesised mediating mechanisms explaining the indirect relationship between education and job, financial, and health satisfactions. Findings also showed that each of these domain satisfactions independently predicts general life satisfaction. Overall, the study shows the importance of education for life satisfaction and highlights the importance of work (i.e., job fit and job satisfaction) for individuals' general subjective well-being.     

Angiotensin II differentially affects hippocampal glial inflammatory markers in young adult male and female mice

Hypertension is a risk factor for neurodegenerative disorders involving inflammation and inflammatory cytokine-producing brain cells (microglia and astrocytes) in the hippocampus and medial prefrontal cortex (mPFC). Here we investigated the effect of slow-pressor angiotensin II (AngII) on gliosis in the hippocampus and mPFC of young adult (2-mo-old) male and female mice. In males, AngII induced hypertension, and this resulted in an increase in the density of the astrocyte marker glial fibrillary acidic protein (GFAP) in the subgranular hilus and a decrease in the density of the microglial marker ionized calcium binding adapter molecule (Iba-1) in the CA1 region. Females infused with AngII did not show hypertension but, significantly, showed alterations in hippocampal glial activation. Compared with vehicle, AngII-infused female mice had an increased density of Iba-1 in the dentate gyrus and CA2/3a region. Like males, females infused with AngII exhibited decreased Iba-1 in the CA1 region. Neither male nor female mice showed differences in GFAP or Iba-1 in the mPFC following AngII infusion. These results demonstrate that the hippocampus is particularly vulnerable to AngII in young adulthood. Differences in gonadal hormones or the sensitivity to AngII hypertension may account for divergences in GFAP and Iba-1 in males and females.

Hypertension is a significant risk factor for neurological disorders such as Alzheimer''s disease (AD) that are associated with neurodegeneration and cognitive decline (Daugherty 2021). Hypertension can develop during the life span yet is often studied at middle and late life. There is emerging evidence that hypertension is becoming more common in late adolescence and early adulthood (Azegami et al. 2021; Hamrahian and Falkner 2022). In addition, there is increasing awareness that the duration of hypertension can impact the onset of neural degeneration (Schaare et al. 2019; Yang et al. 2021) and cognitive dysfunction (Yaffe et al. 2014, 2021; Mahinrad et al. 2020; Zhou et al. 2022). Although the age of onset of hypertension may influence the trajectory of degenerative disease in later life, the effect of hypertension on brain health in young adult subjects is relatively underinvestigated.Hippocampal and medial prefrontal cortical pathology are commonly present in neurodegenerative diseases like AD (Belonwu et al. 2021). Structurally and functionally, both the hippocampus and mPFC also are compromised during hypertension (Raz et al. 2007; Gonzalez et al. 2015; Bu et al. 2018). In the hippocampus, hypertension is known to disrupt cerebrovascular function, promote inflammatory processes, and contribute to neuronal impairment and cognitive decline (Iulita et al. 2018). Although less studied than the hippocampus, the PFC is also compromised by hypertension (Raz et al. 2007; Bu et al. 2018; Wang et al. 2020).Microglia, the resident macrophages in the brain, have been implicated in inflammatory states, cognitive function (Cornell et al. 2022), and the brain''s response to hypertension (Calvillo et al. 2019; Li et al. 2020). An increase in the density of ionized calcium binding adapter molecule (Iba-1), a protein constitutively expressed in microglia and up-regulated when microglia enter an activated stage (Imai et al. 1996; Sasaki et al. 2001), is commonly reported in models of cognitive and neurodegenerative disorders (Prinz et al. 2021).In addition to microglia, astrocytes also have been implicated in the emergence of hippocampal and cortical dysfunction. Astrocytes play critical roles in blood–brain barrier (BBB) formation; brain metabolic, ion, and water homeostasis; neurotransmitter recycling; synapse formation; and neuroimmune signaling (Matias et al. 2019). In the context of insult, pathogen infection, or neurological disease, astrocytes undergo functionally complex reactive responses (Chiu et al. 2014; Giovannoni and Quintana 2020) that are associated with an increase in glial fibrillary acidic protein (GFAP) gene and protein expression (Crespo-Castrillo et al. 2020; Sofroniew 2020).To better understand the consequences of elevated blood pressure on the young adult brain, we conducted an exploratory investigation of the impact of hypertension on the expression of microglia and astrocyte markers—Iba-1 and GFAP, respectively—in the hippocampus and mPFC of male mice. Mice were exposed to angiotensin II (AngII) using the “slow-pressor” model (Dickinson and Lawrence 1963), which in males mimics the gradual rise in blood pressure and increase in sympathetic activation (Grassi and Ram 2016; Lerman et al. 2019) characteristic of essential hypertension (Lerman et al. 2019). Significantly, there is an important sex dimorphism in the risk for hypertension. Compared with men, women are protected from hypertension before middle age but become increasingly affected as they reach perimenopause, and intact young female rodents show a reduced sensitivity to AngII hypertension (Van Kempen et al. 2016). Similarly, there are sex differences in the incidence, progression, and severity of hypertension-associated neurodegenerative disease (Lopez-Lee et al. 2021). Furthermore, sex differences in glial function have also been documented within the context of neurodegenerative diseases (Kodama and Gan 2019; Biechele et al. 2020). Given this evidence, the effect of AngII on hippocampal and medial prefrontal cortical glial markers also was investigated in young intact female mice.     

Interpolation and Amalgamation; Pushing the Limits. Part II

This is the second part of the paper [Part I] which appeared in the previous issue of this journal.