72 research outputs found
Strongly coupled single quantum dot in a photonic crystal waveguide cavity
Cavities embedded in photonic crystal waveguides offer a promising route
towards large scale integration of coupled resonators for quantum
electrodynamics applications. In this letter, we demonstrate a strongly coupled
system formed by a single quantum dot and such a photonic crystal cavity. The
resonance originating from the cavity is clearly identified from the
photoluminescence mapping of the out-of-plane scattered signal along the
photonic crystal waveguide. The quantum dot exciton is tuned towards the cavity
mode by temperature control. A vacuum Rabi splitting of ~ 140 \mueV is observed
at resonance.Comment: 11 pages, 3 figure
Slightly perturbing the arm influences choices between multiple targets
We constantly make choices about how to interact with objects in the environment. Do we immediately consider changes in our posture when making such choices? To find out, we examined whether motion in the background, which is known to influence the trajectory of goal-directed hand movements, influences participantsâ choices when suddenly faced with two options. The participantsâ task was to tap on as many sequentially presented targets as possible within 90 seconds. Sometime after a new target appeared, it split into two targets and participants had to choose which of them to hit. Shortly before the split, the background moved in a way that was expected to result in the finger shifting slightly towards one of the two new targets. We examined whether such shifts influenced the choice between the two targets. The moving background influenced the finger movements in the expected manner: participants moved in the direction of the background motion. It also influenced the choice that participants made between the two targets: participants more frequently chose the target in the direction of the background motion. There was a positive correlation across participants between the magnitude of the response to background motion and the bias to choose the target in the direction of such motion. Thus, people consider sudden changes in their posture when choosing between different movement options
Longitudinal photocurrent spectroscopy of a single GaAs/AlGaAs v-groove quantum wire
Modulation-doped GaAs v-groove quantum wires (QWRs) have been fabricated with
novel electrical contacts made to two-dimensional electron-gas (2DEG)
reservoirs. Here, we present longitudinal photocurrent (photoconductivity/PC)
spectroscopy measurements of a single QWR. We clearly observe conductance in
the ground-state one-dimensional subbands; in addition, a highly
temperature-dependent response is seen from other structures within the
v-groove. The latter phenomenon is attributed to the effects of structural
topography and localization on carrier relaxation. The results of
power-dependent PC measurements suggest that the QWR behaves as a series of
weakly interacting localized states, at low temperatures
Early parenting interventions to prevent internalising problems in children and adolescents: a global systematic review and network meta-analysis
QUESTION: We compared the effectiveness of different types of parenting interventions based on an a priori taxonomy, and the impact of waitlists versus treatment as usual (TAU), in reducing child internalising problems. STUDY SELECTION AND ANALYSIS: We conducted a systematic review and network meta-analysis of published and unpublished randomised controlled trials (RCTs) until 1 October 2022 that investigated parenting interventions with children younger than 4âyears. EXCLUSION CRITERIA: studies with children born preterm, with intellectual disabilities, or families receiving support for current abuse, neglect, and substance misuse. We assessed the certainty of evidence using the Confidence in Network Meta-Analysis framework. We used random-effects network meta-analysis to estimate standardised mean differences (SMDs) with 95% credible intervals (CrIs). FINDINGS: Of 20â520 citations identified, 59 RCTs (18â349 participants) were eligible for the network meta-analysis. Parenting interventions focusing on the dyadic relationship (SMD: -0.26, 95% CrI: -0.43 to -0.08) and those with mixed focus (-0.09, -0.17 to -0.02) were more effective in reducing internalising problems than TAU at the first time point available. All interventions were more effective than waitlist, which increased the risk of internalising problems compared with TAU (0.36, 0.19 to 0.52). All effects attenuated at later follow-ups. Most studies were rated as with 'high risk' or 'some concerns' using the Risk of Bias Assessment Tool V.2. There was no strong evidence of effect modification by theoretically informed components or modifiers. CONCLUSIONS: We found preliminary evidence that relationship-focused and mixed parenting interventions were effective in reducing child internalising problems, and the waitlist comparator increased internalising problems with implications for waiting times between referral and support. Considering the high risk of bias of most studies included, the findings from this meta-analysis should be interpreted with caution. PROSPERO registration number CRD42020172251
Multicohort cross-sectional study of cognitive and behavioural digital biomarkers in neurodegeneration: the Living Lab Study protocol
INTRODUCTION AND AIMS: Digital biomarkers can provide a cost-effective, objective and robust measure for neurological disease progression, changes in care needs and the effect of interventions. Motor function, physiology and behaviour can provide informative measures of neurological conditions and neurodegenerative decline. New digital technologies present an opportunity to provide remote, high-frequency monitoring of patients from within their homes. The purpose of the living lab study is to develop novel digital biomarkers of functional impairment in those living with neurodegenerative disease (NDD) and neurological conditions. METHODS AND ANALYSIS: The Living Lab study is a cross-sectional observational study of cognition and behaviour in people living with NDDs and other, non-degenerative neurological conditions. Patients (nâ„25 for each patient group) with dementia, Parkinson's disease, amyotrophic lateral sclerosis, mild cognitive impairment, traumatic brain injury and stroke along with controls (nâ„60) will be pragmatically recruited. Patients will carry out activities of daily living and functional assessments within the Living Lab. The Living Lab is an apartment-laboratory containing a functional kitchen, bathroom, bed and living area to provide a controlled environment to develop novel digital biomarkers. The Living Lab provides an important intermediary stage between the conventional laboratory and the home. Multiple passive environmental sensors, internet-enabled medical devices, wearables and electroencephalography (EEG) will be used to characterise functional impairments of NDDs and non-NDD conditions. We will also relate these digital technology measures to clinical and cognitive outcomes. ETHICS AND DISSEMINATION: Ethical approvals have been granted by the Imperial College Research Ethics Committee (reference number: 21IC6992). Results from the study will be disseminated at conferences and within peer-reviewed journals
The Social, Educational and Market Scenario for nZEB in Europe
Nearly Zero Energy Buildings (nZEB) are a significant part of the energy efficiency strategy
of the European Union. As buildings represent approximately 40% of the final energy use in Europe,
the reduction of their energy demand is key for a sustainable future. This paper takes a qualitative
approach and presents data about professional and market barriers, as well as the educational market
in relation to the implementation of nZEB policies for new and retrofit buildings in 11 European
countries. Different levels of policy enactments and market penetration are reported and are generally
found to be more advanced in western and central European countries. Furthermore, gender equality
is examined in the building sector in relation to nZEB and presents significant gaps, with a more
balanced situation reported in southern Europe. The accreditation and targeted education of nZEB
experts is still almost non-existent in the examined countries, and the need for training of building
professionals is highlighted as a critical missing component of current policy. This research aims to
be the first step towards the creation of educational material and programmes as a mean to accelerate
the transition to nZEB.European Unionâs Horizon 2020 research and innovation programm
Early parenting interventions to prevent internalising problems in children and adolescents: a global systematic review and network meta-analysis
Question: We compared the effectiveness of different types of parenting interventions based on an a priori taxonomy, and the impact of waitlists versus treatment as usual (TAU), in reducing child internalising problems. Study selection and analysis: We conducted a systematic review and network metaâ analysis of published and unpublished randomised controlled trials (RCTs) until 1 October 2022 that investigated parenting interventions with children younger than 4 years. Exclusion criteria: studies with children born preterm, with intellectual disabilities, or families receiving support for current abuse, neglect, and substance misuse. We assessed the certainty of evidence using the Confidence in Network Metaâ Analysis framework. We used randomâ effects network metaâ analysis to estimate standardised mean differences (SMDs) with 95% credible intervals (CrIs). Findings: Of 20 520 citations identified, 59 RCTs (18 349 participants) were eligible for the network metaâ analysis. Parenting interventions focusing on the dyadic relationship (SMD: â0.26, 95% CrI: â0.43 to â0.08) and those with mixed focus (â0.09, â0.17 to â0.02) were more effective in reducing internalising problems than TAU at the first time point available. All interventions were more effective than waitlist, which increased the risk of internalising problems compared with TAU (0.36, 0.19 to 0.52). All effects attenuated at later followâ ups. Most studies were rated as with âhigh riskâ or âsome concernsâ using the Risk of Bias Assessment Tool V.2. There was no strong evidence of effect modification by theoretically informed components or modifiers. Conclusions: We found preliminary evidence that relationshipâ focused and mixed parenting interventions were effective in reducing child internalising problems, and the waitlist comparator increased internalising problems with implications for waiting times between referral and support. Considering the high risk of bias of most studies included, the findings from this metaâ analysis should be interpreted with caution. PROSPERO registration number CRD42020172251
In vitro studies and preliminary in vivo evaluation of silicified concentrated collagen hydrogels
Hybrid and nanocomposite silicacollagen materials derived from concentrated collagen hydrogels were evaluated in vitro and in vivo to establish their potentialities for biological dressings. Silicification significantly improved the mechanical and thermal stability of the collagen network within the hybrid systems. Nanocomposites were found to favor the metabolic activity of immobilized human dermal fibroblastswhile decreasing the hydrogel contraction. Cell adhesion experiments suggested that in vitro cell behavior was dictated by mechanical properties and surface structure of the scaffold. First-to-date in vivo implantation of bulk hydrogels in subcutaneous sites of rats was performed over the vascular inflammatory period. These materials were colonized and vascularized without inducing strong inflammatory response. These data raise reasonable hope for the future application of silicacollagen biomaterials as biological dressings.Fil: Desimone, MartĂn Federico. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y Metabolismo del FĂĄrmaco. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y Metabolismo del FĂĄrmaco; ArgentinaFil: HĂ©lary, Christophe. UniversitĂ© Pierre et Marie Curie; FranciaFil: Quignard, Sandrine. UniversitĂ© Pierre et Marie Curie; FranciaFil: Rietveld, Ivo B. Universite de Paris; FranciaFil: Bataille, Clement. UniversitĂ© de Versailles Saint-quentin-en-yvelines.; FranciaFil: Copello, Guillermo Javier. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y Metabolismo del FĂĄrmaco. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y Metabolismo del FĂĄrmaco; ArgentinaFil: Mosser, Gervaise. UniversitĂ© Pierre et Marie Curie; FranciaFil: Giraud Guille, Marie-Madeleine. UniversitĂ© Pierre et Marie Curie; FranciaFil: Livage, Jacques. UniversitĂ© Pierre et Marie Curie; FranciaFil: Meddahi PellĂ©, Anne. UniversitĂ© de Versailles Saint-quentin-en-yvelines.; FranciaFil: Coradin, Thibaud. UniversitĂ© Pierre et Marie Curie; Franci
Slightly perturbing the arm influences choices between multiple targets
We constantly make choices about how to interact with objects in the environment. Do we immediately consider changes in our posture when making such choices? To find out, we examined whether motion in the background, which is known to influence the trajectory of goal-directed hand movements, influences participantsâ choices when suddenly faced with two options. The participantsâ task was to tap on as many sequentially presented targets as possible within 90 seconds. Sometime after a new target appeared, it split into two targets and participants had to choose which of them to hit. Shortly before the split, the background moved in a way that was expected to result in the finger shifting slightly towards one of the two new targets. We examined whether such shifts influenced the choice between the two targets. The moving background influenced the finger movements in the expected manner: participants moved in the direction of the background motion. It also influenced the choice that participants made between the two targets: participants more frequently chose the target in the direction of the background motion. There was a positive correlation across participants between the magnitude of the response to background motion and the bias to choose the target in the direction of such motion. Thus, people consider sudden changes in their posture when choosing between different movement options
Scanning near-field photoluminescence mapping of (110)InAs-GaAs self-assembled quantum dots
Scanning near-field optical spectroscopy measurements were carried out for photoluminescence mapping of (110) InAs-GaAs self-assembled quantum dots. Complex line spectra were observed to arise from ground state and excited state ecition complexes. The dot density was found to be about two orders of magnitude lower than in conventional (100) GaAs structures. It was observed that the InAs wetting layer (WL) was relatively rough which may indicate that the thin stress-matching AlAs pre-wetting layer that induced dot growth was not entirely effective
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