638 research outputs found
Effects of polymer polydispersity on the phase behaviour of colloid-polymer mixtures
We study the equilibrium behaviour of a mixture of monodisperse hard sphere
colloids and polydisperse non-adsorbing polymers at their -point, using
the Asakura-Oosawa model treated within the free-volume approximation. Our
focus is the experimentally relevant scenario where the distribution of polymer
chain lengths across the system is fixed. Phase diagrams are calculated using
the moment free energy method, and we show that the mean polymer size at which gas-liquid phase separation first occurs decreases with increasing
polymer polydispersity . Correspondingly, at fixed mean polymer size,
polydispersity favours gas-liquid coexistence but delays the onset of
fluid-solid separation. On the other hand, we find that systems with different
but the same {\em mass-averaged} polymer chain length have nearly
polydispersity-independent phase diagrams. We conclude with a comparison to
previous calculations for a semi-grandcanonical scenario, where the polymer
chemical potentials are imposed, which predicted that fluid-solid coexistence
was over gas-liquid in some areas of the phase diagram. Our results show that
this somewhat counter-intuitive result arose because the actual polymer size
distribution in the system is shifted to smaller sizes relative to the polymer
reservoir distribution.Comment: Changes in v2: sketch in Figure 1 corrected, other figures improved;
added references to experimental work and discussion of mapping from polymer
chain length to effective radiu
Singing to infants matters: early singing interactions affect musical preferences and facilitate vocabulary building
This research revealed that the frequency of reported infant-parent singing interactions predicted 6-month-old infants' performance in laboratory music experiments and mediated their language development in the second year. At 6 months, infants (n=36) were tested using a preferential listening procedure assessing their sustained attention to instrumental and sung versions of the same novel tunes whilst the parents completed an ad-hoc questionnaire assessing home musical interactions with their infants. Language development was assessed with a follow-up when the infants were 14-month-old (n=26). The main results showed that 6-month-olds preferred listening to sung rather than instrumental melodies, and that self-reported high levels of parental singing with their infants[i] were associated with less pronounced preference for the sung over the instrumental version of the tunes at 6 months, and [ii] predicted significant advantages on the language outcomes in the second year. The results are interpreted in relation to conceptions of developmental plasticity
Encouraging vaccination against COVID-19 has no compensatory spillover effects
Effective communication is essential for delivering public health messages and enabling behaviour change. Little is known about possible backfiring, or spillover effects, of COVID-19 vaccine messaging. In a study with n=1,848 United Kingdom (UK) adults, we assess whether communication strategies that target vaccine hesitancy have any unintended, positive or negative, spillover effects on people’s intention to engage in protective, compliance and prosocial behaviours. In June–July 2021, we conducted an online experiment to assess the potential spillover effects of three messages, emphasising (a) the medical benefits of COVID-19 vaccination, (b) the non-medical collective benefits of vaccination or (c) the non-medical individual benefits of holding a vaccination certificate. Exposure to different messages did not significantly affect people’s intention to engage in protective, compliance, or prosocial behaviours. Instead, vaccination status (being vaccinated vs not) was positively associated with intentions to engage in protective, compliance and prosocial behaviours. Our results suggest that communication strategies that aim to increase vaccination uptake do not have any unintended effects on other health behaviours and vaccination campaigns can be tailored to specific populations to increase uptake and compliance
Test of ID carbon-carbon composite prototype tiles for the SPIDER diagnostic calorimeter
Additional heating will be provided to the thermonuclear fusion experiment ITER by injection of neutral beams from accelerated negative ions. In the SPIDER test facility, under construction at Consorzio RFX in Padova (Italy), the production of negative ions will be studied and optimised. To this purpose the STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment) diagnostic will be used to characterise the SPIDER beam during short operation (several seconds) and to verify if the beam meets the ITER requirement regarding the maximum allowed beam non-uniformity (below \ub110%). The most important measurements performed by STRIKE are beam uniformity, beamlet divergence and stripping losses. The major components of STRIKE are 16 1D-CFC (Carbon matrix-Carbon Fibre reinforced Composite) tiles, observed at the rear side by a thermal camera. The requirements of the 1D CFC material include a large thermal conductivity along the tile thickness (at least 10 times larger than in the other directions); low specific heat and density; uniform parameters over the tile surface; capability to withstand localised heat loads resulting in steep temperature gradients. So 1D CFC is a very anisotropic and delicate material, not commercially available, and prototypes are being specifically realised. This contribution gives an overview of the tests performed on the CFC prototype tiles, aimed at verifying their thermal behaviour. The spatial uniformity of the parameters and the ratio between the thermal conductivities are assessed by means of a power laser at Consorzio RFX. Dedicated linear and non-linear simulations are carried out to interpret the experiments and to estimate the thermal conductivities; these simulations are described and a comparison of the experimental data with the simulation results is presented
Sing for me, Mama! Infants' discrimination of novel vowels in song
When adults speak or sing with infants, they sound differently than in adult communication. Infant-directed (ID) communication helps caregivers to regulate infants’ emotions, and helps infants to process speech information, at least from ID-speech. However, it is largely unclear whether infants might also process speech information presented in ID-singing. Therefore, we examined whether infants discriminate vowels in ID-singing, as well as potential differences with ID-speech. Using an Alternating-Trial-Preference-Procedure, infants aged 4-6 and 8-10 months were tested on their discrimination of an unfamiliar non-native vowel contrast presented in ID-like speech and singing. Relying on models of early speech sound perception, we expected that infants in their first half year of life would discriminate the vowels, in contrast to older infants whose non-native sound perception should deteriorate, at least in ID-like speech. Our results showed that infants of both age groups were able to discriminate the vowels in ID-like singing, while only the younger group discriminated the vowels in ID-like speech. These results show that infants process speech sound information in song from early on. They also hint at diverging perceptual or attentional mechanisms guiding infants’ sound processing in ID-speech vs. -singing towards the end of the first year of life
Unique neuronal tracers show migration and differentiation of SVZ progenitors in organotypic slices.
Is premature birth an environmental sensitivity factor? A scoping review protocol
Introduction Globally, around 10% of children are born
preterm and are more at risk of negative developmental
outcomes. However, empirical evidences and theoretical
reasoning also suggest that premature birth can be
a susceptibility factor, increasing sensitivity to the
environment for better and for worse. Because available
findings are controversial, with the current scoping
review we will explore if, based on the available literature,
preterm birth can be seen as an environmental sensitivity
(ES) factor. In doing so, we will consider a series of
moderating variables, including the level of prematurity,
the type of environment and the outcome investigated.
Methodological aspects, as the type of measures used and
study design, will be considered.
Methods and analysis The scoping review will
be conducted following the Joanna Briggs Institute
Methodology guidelines. The report will follow the
Preferred Reporting Items for Systematic Reviews and
Meta-Analyses extension for Scoping Reviews checklist.
We will perform the search between 15 January 2022 and
1 February 2022. Data will be chartered by independent
reviewers.
Ethics and dissemination Ethical approval is not
required, as primary data will not be collected. This
scoping review will be the first to explore whether
prematurity is associated with an increased ES. This
review can have important implications for tailoring
prevention and intervention programmes. Results will be
published in a peer-reviewed journal
HuMOVE: a low-invasive wearable monitoring platform in sexual medicine
OBJECTIVE: To investigate an accelerometer-based wearable system, named Human Movement (HuMOVE) platform, designed to enable quantitative and continuous measurement of sexual performance with minimal invasiveness and inconvenience for users. MATERIALS AND METHODS: Design, implementation, and development of HuMOVE, a wearable platform equipped with an accelerometer sensor for monitoring inertial parameters for sexual performance assessment and diagnosis, were performed. The system enables quantitative measurement of movement parameters during sexual intercourse, meeting the requirements of wearability, data storage, sampling rate, and interfacing methods, which are fundamental for human sexual intercourse performance analysis. HuMOVE was validated through characterization using a controlled experimental test bench and evaluated in a human model during simulated sexual intercourse conditions. RESULTS: HuMOVE demonstrated to be a robust and quantitative monitoring platform and a reliable candidate for sexual performance evaluation and diagnosis. Characterization analysis on the controlled experimental test bench demonstrated an accurate correlation between the HuMOVE system and data from a reference displacement sensor. Experimental tests in the human model during simulated intercourse conditions confirmed the accuracy of the sexual performance evaluation platform and the effectiveness of the selected and derived parameters. The obtained outcomes also established the project expectations in terms of usability and comfort, evidenced by the questionnaires that highlighted the low invasiveness and acceptance of the device. CONCLUSION: To the best of our knowledge, HuMOVE platform is the first device for human sexual performance analysis compatible with sexual intercourse; the system has the potential to be a helpful tool for physicians to accurately classify sexual disorders, such as premature or delayed ejaculation
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