426 research outputs found
Comparing the benefits of parent-infant flute and singing groups for communication and parenting: A feasibility study
There is growing evidence highlighting benefits of musical exposure and participation on several aspects of development and parenting. Aiming to establish a rigorous protocol allowing researchers to study different types of musical interactions and their benefits on the development of early communication, the present study explored parentsâ experiences of musically engaging with their infants in different types of music groups. Twenty-five infants and their parents were randomly assigned to one of three groups: (1) singing, (2) flute playing or (3) control group. Music sessions were held weekly for 14 weeks and were followed by the home use of the recorded routines specific of each group, for further three months. Semi structured interviews were conducted with the experimental groupsâ participants, and pre/post quantitative developmental measures were collected from all groups, to assess participantsâ compliance. Qualitative analyses of the interviews revealed both shared themes, (communication enhancement, enjoyment and regulation); and unique themes (creativity and freedom in the flute group; familiarity and responsiveness in the singing group). The feasibility study was successful in establishing a workable protocol to use in RCT longitudinal interventions aiming to examine how specific aspects of the musical experience might differentially support developmental outcomes, in parent-infant groups
The soundscape of neonatal intensive care: a mixed-methods study of the parentsâ experience
Parents who have infants hospitalised in neonatal intensive care units (NICUs) experience high levels of stress, including post-traumatic stress disorder (PTSD) symptoms. However, whether sounds contribute to parentsâ stress remains largely unknown. Critically, researchers lack a com-prehensive instrument to investigate the relationship between sounds in NICUs and parental stress. To address this gap, this report presents the âSoundscape of NICU Questionnaireâ (SON-Q), which was developed specifically to capture parentsâ perceptions and beliefs about the impact that sound had on them and their infants, from pre-birth throughout the NICU stay and in the first postdischarge period. Parents of children born preterm (n = 386) completed the SON-Q and the Perinatal PTSD Questionnaire (PPQ). Principal Component Analysis identifying underly-ing dimensions comprising the parental experience of the NICU soundscape was followed by an exploration of the relationships between subscales of the SON-Q and the PPQ. Moderation analy-sis was carried out to further elucidate relationships between variables. Finally, thematic analy-sis was employed to analyse one memory of sounds in NICU open question. The results highlight systematic associations between aspects of the NICU soundscape and parental stress/trauma. The findings underscore the importance of developing specific studies in this area and devising inter-ventions to best support parentsâ mental health, which could in turn support infantsâ develop-mental outcomes
Photon Ring Autocorrelations
In the presence of a black hole, light sources connect to observers along
multiple paths. As a result, observed brightness fluctuations must be
correlated across different times and positions in black hole images. Photons
that execute multiple orbits around the black hole appear near a critical curve
in the observer sky, giving rise to the photon ring. In this paper, a novel
observable is proposed: the two-point correlation function of intensity
fluctuations on the photon ring. This correlation function is analytically
computed for a Kerr black hole surrounded by stochastic equatorial emission,
with source statistics motivated by simulations of a turbulent accretion flow.
It is shown that this two-point function exhibits a universal, self-similar
structure consisting of multiple peaks of identical shape: while the profile of
each peak encodes statistical properties of fluctuations in the source, the
locations and heights of the peaks are determined purely by the black hole
parameters. Measuring these peaks would demonstrate the existence of the photon
ring without resolving its thickness, and would provide estimates of black hole
mass and spin. With regular monitoring over sufficiently long timescales, this
measurement could be possible via interferometric imaging with modest
improvements to the Event Horizon Telescope.Comment: 31 pages, 3 figure
Seeing an exercise as a single mathematical object: using variation to structure sense-making
In this theoretical paper we take an exercise to be a collection of procedural questions or tasks. It can be useful to treat such an exercise as a single object, with individual questions seen as elements in a mathematically and pedagogically structured set. We use the notions of 'dimensions of possible variation' and 'range of permissible change', derived from Ference Marton, to discuss affordances and constraints of some sample exercises. This gives insight into the potential pedagogical role of exercises, and shows how exercise analysis and design might contribute to hypotheses about learning trajectories. We argue that learners' response to an exercise has something in common with modeling that we might call 'micro-modeling', but we resort to a more inclusive description of mathematical thinking to describe learners' possible responses to a well-planned exercise. Finally we indicate how dimensions of possible variation inform the design and use of an exercise
High and Low Dimensions in The Black Hole Negative Mode
The negative mode of the Schwarzschild black hole is central to Euclidean
quantum gravity around hot flat space and for the Gregory-Laflamme black string
instability. We analyze the eigenvalue as a function of space-time dimension by
constructing two perturbative expansions: one for large d and the other for
small d-3, and determining as many coefficients as we are able to compute
analytically. Joining the two expansions we obtain an interpolating rational
function accurate to better than 2% through the whole range of dimensions
including d=4.Comment: 17 pages, 4 figures. v2: added reference. v3: published versio
A simple method for developing lysine targeted covalent protein reagents
Peptide-based covalent probes can target shallow protein surfaces not typically addressable using small molecules, yet there is a need for versatile approaches to convert native peptide sequences into covalent binders that can target a broad range of residues. Here we report protein-based thio-methacrylate estersâelectrophiles that can be installed easily on unprotected peptides and proteins via cysteine side chains, and react efficiently and selectively with cysteine and lysine side chains on the target. Methacrylate phosphopeptides derived from 14-3-3-binding proteins irreversibly label 14-3-3Ď via either lysine or cysteine residues, depending on the position of the electrophile. Methacrylate peptides targeting a conserved lysine residue exhibit pan-isoform binding of 14-3-3 proteins both in lysates and in extracellular media. Finally, we apply this approach to develop protein-based covalent binders. A methacrylate-modified variant of the colicin E9 immunity protein irreversibly binds to the E9 DNAse, resulting in significantly higher thermal stability relative to the non-covalent complex. Our approach offers a simple and versatile route to convert peptides and proteins into potent covalent binders.</p
Many-body dispersions in interacting ballistic quantum wires
We have measured the collective excitation spectrum of interacting electrons
in one-dimension. The experiment consists of controlling the energy and
momentum of electrons tunneling between two clean and closely situated,
parallel quantum wires in a GaAs/AlGaAs heterostructure while measuring the
resulting conductance. We measure excitation spectra that clearly deviate from
the non-interacting spectrum, attesting to the importance of Coulomb
interactions. Notable is an observed 30% enhancement of the velocity of the
main excitation branch relative to non-interacting electrons with the same
density. In short wires, finite size effects resulting from broken
translational invariance are observed. Spin - charge separation is manifested
through moire patterns, reflecting different spin and charge excitation
velocities.Comment: 14 pages, 6 eps figures. To be published in NANOWIRE, a special issue
of Solid State Communication
RGS2 expression predicts amyloid-β sensitivity, MCI and Alzheimer's disease: genome-wide transcriptomic profiling and bioinformatics data mining
Alzheimer's disease (AD) is the most frequent cause of dementia. Misfolded protein pathological hallmarks of AD are brain deposits of amyloid-β (Aβ) plaques and phosphorylated tau neurofibrillary tangles. However, doubts about the role of Aβ in AD pathology have been raised as Aβ is a common component of extracellular brain deposits found, also by in vivo imaging, in non-demented aged individuals. It has been suggested that some individuals are more prone to Aβ neurotoxicity and hence more likely to develop AD when aging brains start accumulating Aβ plaques. Here, we applied genome-wide transcriptomic profiling of lymphoblastoid cells lines (LCLs) from healthy individuals and AD patients for identifying genes that predict sensitivity to Aβ. Real-time PCR validation identified 3.78-fold lower expression of RGS2 (regulator of G-protein signaling 2; P=0.0085) in LCLs from healthy individuals exhibiting high vs low Aβ sensitivity. Furthermore, RGS2 showed 3.3-fold lower expression (P=0.0008) in AD LCLs compared with controls. Notably, RGS2 expression in AD LCLs correlated with the patients' cognitive function. Lower RGS2 expression levels were also discovered in published expression data sets from postmortem AD brain tissues as well as in mild cognitive impairment and AD blood samples compared with controls. In conclusion, Aβ sensitivity phenotyping followed by transcriptomic profiling and published patient data mining identified reduced peripheral and brain expression levels of RGS2, a key regulator of G-protein-coupled receptor signaling and neuronal plasticity. RGS2 is suggested as a novel AD biomarker (alongside other genes) toward early AD detection and future disease modifying therapeutics
Benchmark of Schemes for Multiscale Molecular Dynamics Simulations
In multiscale molecular dynamics simulations the accuracy of detailed models is combined with the efficiency of a reduced representation. For several applications - namely those of sampling enhancement - it is desirable to combine fine-grained (FG) and coarse-grained (CG) approaches into a single hybrid approach with an adjustable mixing parameter. We present a benchmark of three algorithms that use a mixing of the two representation layers using a Lagrangian formalism. The three algorithms use three different approaches for keeping the particles at the FG level of representation together: 1) addition of forces, 2) mass scaling, and 3) temperature scaling. The benchmark is applied to liquid hexadecane and includes an evaluation of the average configurational entropy of the FG and CG subsystems. The temperature-scaling scheme achieved a 3-fold sampling speedup with little deviation of FG properties. The addition-of-forces scheme kept FG properties the best but provided little sampling speedup. The mass-scaling scheme yielded a 5-fold speedup but deviated the most from FG properties
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