246 research outputs found

    Fabrication of single‐crystalline InSb‐on‐insulator by rapid melt growth

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    InSb has the smallest bandgap and highest electron mobility among III‐V semiconductors and is widely used for photodetectors and high‐frequency electronic applications. Integration of InSb directly on Si would drastically reduce the fabrication cost and enable new applications, however, it is very challenging due to its 19% lattice mismatch with Si. Herein, the integration of single‐crystalline InSb microstructures on insulator‐covered Si through rapid melt growth (RMG) is reported and specifically provides details on the fabrication process. The importance of achieving high‐quality conformal capping layers at low thermal budget to contain the InSb melt is assessed when the sample is annealed. The importance of ensuring a pristine Si seed area to achieve single‐crystalline InSb is illustrated and demonstrated here for the first time

    Relationship Between Venules and Perivascular Spaces in Sporadic Small Vessel Diseases

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    Background and Purpose— Perivascular spaces (PVS) around venules may help drain interstitial fluid from the brain. We examined relationships between suspected venules and PVS visible on brain magnetic resonance imaging. Methods— We developed a visual venular quantification method to examine the spatial relationship between venules and PVS. We recruited patients with lacunar stroke or minor nondisabling ischemic stroke and performed brain magnetic resonance imaging and retinal imaging. We quantified venules on gradient echo or susceptibility-weighted imaging and PVS on T2-weighted magnetic resonance imaging in the centrum semiovale and then determined overlap between venules and PVS. We assessed associations between venular count and patient demographic characteristics, vascular risk factors, small vessel disease features, retinal vessels, and venous sinus pulsatility. Results— Among 67 patients (69% men, 69.0±9.8 years), only 4.6% (range, 0%–18%) of venules overlapped with PVS. Total venular count increased with total centrum semiovale PVS count in 55 patients after accounting for venule-PVS overlap (ÎČ=0.468 [95% CI, 0.187–0.750]) and transverse sinus pulsatility (ÎČ=0.547 [95% CI, 0.309–0.786]) and adjusting for age, sex, and systolic blood pressure. Conclusions— Despite increases in both visible PVS and suspected venules, we found minimal spatial overlap between them in patients with sporadic small vessel disease, suggesting that most magnetic resonance imaging-visible centrum semiovale PVS are periarteriolar rather than perivenular

    Father–Daughter Bonds: A Comparison of Adolescent Daughters’ Relationships with Resident Biological Fathers and Stepfathers

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    Objective: To investigate whether the interpersonal dynamics of closeness are different in stepfather–stepdaughter versus father–daughter relationships during adolescence. Background: Establishing a general process model of the relational factors contributing to greater closeness between fathers and daughters is a preliminary step toward examining variations in such processes. Method: The data were from the National Longitudinal Study of Adolescent to Adult Health (ADD Health), a nationally representative sample of adolescents. Respondents were female adolescents who were living with either a biological father (n = 1,881) or stepfather (n = 273) and reported on the availability and involvement of their (step)fathers, as well as the communication and closeness in their relationship with him. Results: Involvement and communication were predictors of closeness in both types of relationships, however, communication was a stronger predictor of closeness between stepfathers and stepdaughters. For adolescent girls living with a stepfather, greater involvement with their stepfathers was associated with greater closeness to their non-resident biological fathers. The length of the relationship between stepfathers and stepdaughters was not associated with levels of closeness. Conclusions: Overall, these findings suggest that stepfather–stepdaughter relationships reflect similar interpersonal dynamics as father–daughter relationships but that establishing and maintaining these relationships through meaningful communication may be particularly important for stepfathers and stepdaughters. Implications: Practitioners working to help stepfamilies build stronger relationships may want to stress that investing in shared activities and maintaining meaningful communication can be particularly important for establishing and maintaining positive relationships between stepfathers and stepdaughters

    Combined acoustical and visual performance of noise barriers in mitigating the environmental impact of motorways.

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    This study investigated the overall performance of noise barriers in mitigating environmental impact of motorways, taking into consideration their effects on reducing noise and visual intrusions of moving traffic, but also potentially inducing visual impact themselves. A laboratory experiment was carried out, using computer-visualised video scenes and motorway traffic noise recordings to present experimental scenarios covering two traffic levels, two distances of receiver to road, two types of background landscape, and five barrier conditions including motorway only, motorway with tree belt, motorways with 3 m timber barrier, 5 m timber barrier, and 5 m transparent barrier. Responses from 30 participants of university students were gathered and perceived barrier performance analysed. The results show that noise barriers were always beneficial in mitigating environmental impact of motorways, or made no significant changes in environmental quality when the impact of motorways was low. Overall, barriers only offered similar mitigation effect as compared to tree belt, but showed some potential to be more advantageous when traffic level went high. 5 m timber barrier tended to perform better than the 3 m one at the distance of 300 m but not at 100 m possibly due to its negative visual effect when getting closer. The transparent barrier did not perform much differently from the timber barriers but tended to be the least effective in most scenarios. Some low positive correlations were found between aesthetic preference for barriers and environmental impact reduction by the barriers

    Rationale and design of a longitudinal study of cerebral small vessel diseases, clinical and imaging outcomes in patients presenting with mild ischaemic stroke: Mild Stroke Study 3

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    Background: Cerebral small vessel disease is a major cause of dementia and stroke, visible on brain magnetic resonance imaging. Recent data suggest that small vessel disease lesions may be dynamic, damage extends into normal-appearing brain and microvascular dysfunctions include abnormal blood–brain barrier leakage, vasoreactivity and pulsatility, but much remains unknown regarding underlying pathophysiology, symptoms, clinical features and risk factors of small vessel disease. Patients and Methods: The Mild Stroke Study 3 is a prospective observational cohort study to identify risk factors for and clinical implications of small vessel disease progression and regression among up to 300 adults with non-disabling stroke. We perform detailed serial clinical, cognitive, lifestyle, physiological, retinal and brain magnetic resonance imaging assessments over one year; we assess cerebrovascular reactivity, blood flow, pulsatility and blood–brain barrier leakage on magnetic resonance imaging at baseline; we follow up to four years by post and phone. The study is registered ISRCTN 12113543. Summary: Factors which influence direction and rate of change of small vessel disease lesions are poorly understood. We investigate the role of small vessel dysfunction using advanced serial neuroimaging in a deeply phenotyped cohort to increase understanding of the natural history of small vessel disease, identify those at highest risk of early disease progression or regression and uncover novel targets for small vessel disease prevention and therapy

    Developing a novel tool to assess liking and wanting in infants at the time of complementary feeding - The Feeding Infants: Behaviour and Facial Expression Coding System (FIBFECS)

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    Introduction: Consumption of foods is determined in part by how much a food is liked. However, assessing liking in infants is difficult. Research with infants has often relied on indirect measures such as intake or subjective ratings from mothers. Therefore the aim of the present research was to devise a tool adapted from existing techniques which can directly and systematically measure liking in infants during the weaning period. Method: A tool was developed by extracting items from previous studies. In all, 13 items were generated, which included 6 behaviours reflecting avoidance and approach: turning away, arching back, pushing spoon away, crying/fussy, leaning forward and rate of acceptance; also 7 facial expressions thought to reflect affective response; brow lowered, inner brow raised, squinting, nose wrinkling, upper lip raised, lip corners down and gaping. An e-training manual was developed with a certification test to train coders. The coding tool is based on coding the first 9 spoonfuls for each infant. 63 videos were coded by 4 raters, each video was coded by at least 2 different coders. For each spoonful the absence or presence of each item was recorded; for rate of acceptance, a four point scale was used. Results: In the certification test most cues were high in agreement for all coders. Factor analysis indicated two dimensions, one which largely captured gross behaviours and the second featuring a cluster of facial expressions. Internal consistencies of the overall scale and the behaviour and facial expression subscales were acceptable as indicated by Cronbach's alpha >0.7. Intra-class correlation indicated moderate to high inter-rater reliability and test-retest reliability for most of the cues. Spearman correlations indicated significant associations of the total number of negative behaviours with rate of acceptance and overall facial expressions. Rejection behaviours corresponded with a low rate of food acceptance and a high rate of negative facial expressions. Two parameters occurred less frequently and did not appear to provide any further discriminatory ability, namely leaning forward and crying/fussiness, these can be removed from the scale for future use. Conclusions: The Feeding Infants: Behaviour and Facial Expression Coding System (FIBFECS) is structurally valid and reliable for use by trained coders and those who are researching infant eating behaviour. The two factor structure of the tool suggests that the facial expression subscale reflects liking and the behaviour subscale wanting. The tool could also be adapted for mothers and professionals to detect liking and wanting through facial expression and behavioural cues respectively

    Tales of Emergence - Synthetic Biology as a Scientific Community in the Making

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    International audienceThis article locates the beginnings of a synthetic biology network and thereby probes the formation of a potential disciplinary community. We consider the ways that ideas of community are mobilized, both by scientists and policy-makers in building an agenda for new forms of knowledge work, and by social scientists as an analytical device to understand new formations for knowledge production. As participants in, and analysts of, a network in synthetic biology, we describe our current understanding of synthetic biology by telling four tales of community making. The first tale tells of the mobilization of synthetic biology within a European context. The second tale describes the approach to synthetic biology community formation in the UK. The third narrates the creation of an institutionally based, funded 'network in synthetic biology'. The final tale de-localizes community-making efforts by focussing on 'devices' that make communities. In tying together these tales, our analysis suggests that the potential community can be understood in terms of 'movements'--the (re)orientation and enrolment of people, stories, disciplines and policies; and of 'stickiness'--the objects and glues that begin to bind together the various constitutive elements of community

    Application and validation of the Feeding Infants: Behaviour and Facial Expression Coding System (FIBFECS) to assess liking and wanting in infants at the time of complementary feeding

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    Introduction: The aim of this study was to validate a novel tool developed to measure liking and wanting in infants during the weaning period. The Feeding Infants: Behaviour and Facial Expression Coding System (FIBFECS; Hetherington et al., in press) is an evidence based video coding tool, consisting of 13 items. There are 6 measures of avoidance/approach behaviours (turns head away, arches back, pushes spoon away, crying/fussy, leaning forward and rate of acceptance) to assess wanting and 7 facial expressions (brow lowered, inner brow raised, squinting, nose wrinkling, lip corners down, upper lip raised and gaping) to assess liking. Lower scores on the total scale indicated greater wanting and/or liking. The tool was applied to a recent randomized control trial (Hetherington et al., 2015). Method: 36 mother-infant dyads took part in the study and were randomised to the intervention or the control group. Infants were filmed on two occasions whilst eating a generally liked vegetable (carrots) and less preferred vegetable (green bean). 72 video extracts were coded by 4 trained researchers with adequate certification scores, each video was coded by at least two coders. Items and scales were tested for discrimination ((1) intervention vs control; (2) liked vs disliked vegetable) and construct validity (correlation with intake and liking assessed by mother and researcher). Results: Very good discrimination (p < 0.001) was obtained for carrots vs green bean for the total score and total negative facial expressions and rejection behaviours (p=0.003). Discrimination for the intervention vs control groups was only obtained for the total rejections and the rate of acceptance (p < 05). The FIBFECS subscales had good construct validity as these were significantly correlated with intake and liking ratings (p < 0.01). Items such as crying/fussy and leaning forward were removed from the scale as well as inner brow raised, squinting and lip corners down, as these do not correlate with other variables. Their removal did not affect the integrity of the scale. The rate of acceptance parameter was found to have potential as a short method to measure wanting in infants. Conclusion: The present study has demonstrated that the FIBFECS can be used to identify liking and wanting independent of subjective ratings from mothers and researchers, therefore, this tool can be used widely in the study of infant responses to novel foods at the time of weaning. There is potential to develop the tool for infants beyond the period of complementary feeding and to assist in identifying fussy eating in the early stages of development
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