433 research outputs found
Review of No Rules Rule: Netflix and the Culture of Reinvention
Review of
No Rules Rule: Netflix and the Culture of Reinvention
Reed Hastings, Netflix co-founder and CEO & Erin Meyer, INSEAD Business School
Paperback, Large Print, 464 pages
Published in September 2020 by Random House Large Print Publishing
ISBN 0593152387 (ISBN13: 9780593152386)
Edition Language - English
Literary Awards: Financial Times and McKinsey Business Book of the Year Nominee for Shortlist (2020
Schrieffer-Wolff transformation for quantum many-body systems
The Schrieffer-Wolff (SW) method is a version of degenerate perturbation
theory in which the low-energy effective Hamiltonian H_{eff} is obtained from
the exact Hamiltonian by a unitary transformation decoupling the low-energy and
high-energy subspaces. We give a self-contained summary of the SW method with a
focus on rigorous results. We begin with an exact definition of the SW
transformation in terms of the so-called direct rotation between linear
subspaces. From this we obtain elementary proofs of several important
properties of H_{eff} such as the linked cluster theorem. We then study the
perturbative version of the SW transformation obtained from a Taylor series
representation of the direct rotation. Our perturbative approach provides a
systematic diagram technique for computing high-order corrections to H_{eff}.
We then specialize the SW method to quantum spin lattices with short-range
interactions. We establish unitary equivalence between effective low-energy
Hamiltonians obtained using two different versions of the SW method studied in
the literature. Finally, we derive an upper bound on the precision up to which
the ground state energy of the n-th order effective Hamiltonian approximates
the exact ground state energy.Comment: 47 pages, 3 figure
Group-Based Parent Training Interventions for Parents of Children with Autism Spectrum Disorders: a Literature Review
© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Parents of children with autism spectrum disorders should have access to interventions to help them understand and support their child. This literature review examines the existing evidence for group-based parent training interventions that support parents of children with autism. From the literature, core intervention processes and outcomes are identified and include parenting and parent behaviour, parent health, child behaviour and peer and social support. Results show a positive trend for intervention effectiveness, but findings are limited by low-quality studies and heterogeneity of intervention content, outcomes and outcome measurement. Future research should focus on specifying effective intervention ingredients and modes of delivery, consistent and reliable outcome measurement, and improving methodological rigour to build a more robust evidence base
On quantum mean-field models and their quantum annealing
This paper deals with fully-connected mean-field models of quantum spins with
p-body ferromagnetic interactions and a transverse field. For p=2 this
corresponds to the quantum Curie-Weiss model (a special case of the
Lipkin-Meshkov-Glick model) which exhibits a second-order phase transition,
while for p>2 the transition is first order. We provide a refined analytical
description both of the static and of the dynamic properties of these models.
In particular we obtain analytically the exponential rate of decay of the gap
at the first-order transition. We also study the slow annealing from the pure
transverse field to the pure ferromagnet (and vice versa) and discuss the
effect of the first-order transition and of the spinodal limit of metastability
on the residual excitation energy, both for finite and exponentially divergent
annealing times. In the quantum computation perspective this quantity would
assess the efficiency of the quantum adiabatic procedure as an approximation
algorithm.Comment: 44 pages, 23 figure
Quantum harmonic oscillator systems with disorder
We study many-body properties of quantum harmonic oscillator lattices with
disorder. A sufficient condition for dynamical localization, expressed as a
zero-velocity Lieb-Robinson bound, is formulated in terms of the decay of the
eigenfunction correlators for an effective one-particle Hamiltonian. We show
how state-of-the-art techniques for proving Anderson localization can be used
to prove that these properties hold in a number of standard models. We also
derive bounds on the static and dynamic correlation functions at both zero and
positive temperature in terms of one-particle eigenfunction correlators. In
particular, we show that static correlations decay exponentially fast if the
corresponding effective one-particle Hamiltonian exhibits localization at low
energies, regardless of whether there is a gap in the spectrum above the ground
state or not. Our results apply to finite as well as to infinite oscillator
systems. The eigenfunction correlators that appear are more general than those
previously studied in the literature. In particular, we must allow for
functions of the Hamiltonian that have a singularity at the bottom of the
spectrum. We prove exponential bounds for such correlators for some of the
standard models
Comprehensive splice-site analysis using comparative genomics
We have collected over half a million splice sites from five species—Homo sapiens, Mus musculus, Drosophila melanogaster, Caenorhabditis elegans and Arabidopsis thaliana—and classified them into four subtypes: U2-type GT–AG and GC–AG and U12-type GT–AG and AT–AC. We have also found new examples of rare splice-site categories, such as U12-type introns without canonical borders, and U2-dependent AT–AC introns. The splice-site sequences and several tools to explore them are available on a public website (SpliceRack). For the U12-type introns, we find several features conserved across species, as well as a clustering of these introns on genes. Using the information content of the splice-site motifs, and the phylogenetic distance between them, we identify: (i) a higher degree of conservation in the exonic portion of the U2-type splice sites in more complex organisms; (ii) conservation of exonic nucleotides for U12-type splice sites; (iii) divergent evolution of C.elegans 3′ splice sites (3′ss) and (iv) distinct evolutionary histories of 5′ and 3′ss. Our study proves that the identification of broad patterns in naturally-occurring splice sites, through the analysis of genomic datasets, provides mechanistic and evolutionary insights into pre-mRNA splicing
Parenting stress and depressive symptoms in Taiwanese mothers of young children with autism spectrum disorder: association with children's behavioural problems
Background: This study examined the severity of parenting stress and depressive symptoms in Taiwanese mothers of young children with autism spectrum disorder (ASD) compared to mothers of young children with developmental delay (DD). The associations between parenting stress, depressive symptoms, and children’s behavioural problems were also tested.
Methods: The study sample included 51 young children with ASD (mean age = 31 months), 51 young children with DD (mean age = 30 months) and their mothers.
Results: The results confirmed that mothers of young children with ASD experienced higher levels of parenting stress and depressive symptoms than mothers of young children with DD. In addition, children’s behavioural problems were robust predictors of parenting stress and depressive symptoms in mothers of young children with ASD, but not in mothers of young children with DD.
Conclusion: The findings indicated that one of the critical goals in early intervention for young children with ASD and their families is to reduce children’s behavioural problems
Live imaging of altered period1 expression in the suprachiasmatic nuclei of Vipr2−/− mice1
Vasoactive intestinal polypeptide and its receptor, VPAC2, play important roles in the functioning of the brain’s circadian clock in the suprachiasmatic nuclei (SCN). Mice lacking VPAC2 receptors (Vipr2−/−) show altered circadian rhythms in locomotor behavior, neuronal firing rate, and clock gene expression, however, the nature of molecular oscillations in individual cells is unclear. Here, we used real-time confocal imaging of a destabilized green fluorescent protein (GFP) reporter to track the expression of the core clock gene Per1 in live SCN-containing brain slices from wild-type (WT) and Vipr2−/− mice. Rhythms in Per1-driven GFP were detected in WT and Vipr2−/− cells, though a significantly lower number and proportion of cells in Vipr2−/− slices expressed detectable rhythms. Further, Vipr2−/− cells expressed significantly lower amplitude oscillations than WT cells. Within each slice, the phases of WT cells were synchronized whereas cells in Vipr2−/− slices were poorly synchronized. Most GFP-expressing cells, from both genotypes, expressed neither vasopressin nor vasoactive intestinal polypeptide. Pharmacological blockade of VPAC2 receptors in WT SCN slices partially mimicked the Vipr2−/− phenotype. These data demonstrate that intercellular communication via the VPAC2 receptor is important for SCN neurons to sustain robust, synchronous oscillations in clock gene expression
Barriers and facilitators to primary health care for people with intellectual disabilities and/or autism: an integrative review
Background
Globally, people with intellectual disabilities, autism, or both, experience health inequalities. Death occurs at a younger age and the prevalence of long-term morbidities is higher than in the general population. Despite this, their primary healthcare access rates are lower, their health needs are often unmet, and their views and experiences are frequently overlooked in research, policy and practice.
Aim
To investigate the barriers and facilitators reported by individuals with intellectual disabilities, autism or both, and / or their carers, to accessing and utilising primary healthcare for their physical and mental health needs.
Design and setting
An integrative review utilising systematic review methodology. (PROSPERO: CRD42018103103).
Method
Electronic databases MEDLINE, Embase, CINAHL and Cochrane were searched for relevant studies (all languages) using a search strategy. Two researchers independently screened the results and assessed the quality of studies.
Results
Sixty-three international studies were identified. Six main themes relating to barriers and facilitators emerged from an analysis of these studies. The themes included training; knowledge and awareness; communication; fear and embarrassment; involvement in healthcare decision-making; and time. All the themes were underpinned by the need for greater care, dignity, respect, collaborative relationships and the need for reasonable adjustments. Opposing barriers and facilitators were identified within each of the main themes.
Conclusions
Adolescents and adults with intellectual disabilities, autism, or both, experience several barriers to accessing and utilising primary healthcare. The findings highlight the reasonable adjustments and facilitators that can be implemented to ensure that these individuals are not excluded from primary healthcare.
How this fits in?
This review synthesises evidence on the barriers and facilitators to accessing and utilising primary healthcare perceived by people with intellectual disabilities, autism or both. The findings highlight important considerations for primary healthcare policy, practice and further research
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