113,294 research outputs found
Is the incidence of dementia declining?
Action on preventative health could lower the risk of dementia for future generations, argues this report.
Executive summary
The world-wide projections of the prevalence of dementia in the coming decades have been a source of great concern to health systems and societies around the world. The World Alzheimer Report 2010 estimated that there were 36 million people with dementia in 2010, with an expected doubling every 20 years to nearly 115 million in 2050. These sobering figures are based on assumptions that the age-adjusted prevalence of dementia would remain constant and the population would continue to age at the current rate.
The assumption that the incidence of dementia will remain stable is now being put into question. There is emerging evidence to suggest that the incidence of dementia in older individuals may be declining. It appears that this change may be recent and has possibly occurred only in the last one to two decades. It may also be restricted so far to high income countries, although data from low and middle income countries are lacking.
The reasons for this change are not understood, but education, more stimulating environments and better control of vascular risk factors may have contributed. The data are still preliminary and more studies are needed to establish the extent of this change and understand its causes. It should be noted that the decline is not large enough to offset the increase in prevalence of dementia due to the ageing of the population and therefore investment and efforts to develop better treatments and care for people with dementia need to continue.
The fact that dementia rates are malleable is an encouraging finding but the reduction cannot be taken for granted as gains in population health can easily be lost if societies do not remain vigilant and continually proactive. These preliminary findings provide a strong argument for large scale Government investment in dementia-prevention strategies, which should start from early life
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
Supplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Invariance group properties and exact solutions of equations describing time-dependent free surface flows under gravity
Using the method of infinitesimal transformations, a 6-parameter family of exact solutions describing nonlinear sheared flows with a free surface are found. These solutions are a hybrid between the earlier self-propagating simple wave solutions of Freeman, and decaying solutions of Sachdev. Simple wave solutions are also derived via the method of infinitesimal transformations. Incomplete beta functions seem to characterize these (nonlinear) sheared flows in the absence of critical levels
Superfluid-Insulator Transitions of the Fermi Gas with Near-Unitary Interactions in a Periodic Potential
We consider spin-1/2 fermions of mass m with interactions near the unitary limit. In an applied periodic potential of amplitude V and period a(L), and with a density of an even integer number of fermions per unit cell, there is a second-order quantum phase transition between superfluid and insulating ground states at a critical V = V(c). We compute the universal ratio V(c)ma(L)(2)/h(2) at N = infinity in a model with Sp(2N) spin symmetry. The insulator interpolates between a band insulator of fermions and a Mott insulator of fermion pairs. We discuss implications for recent experiments
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Flat space holography and the complex Sachdev-Ye-Kitaev model
We provide the first steps toward a flat space holographic correspondence in two bulk spacetime dimensions. The gravity side is described by a conformally transformed version of the matterless Callan-Giddings-Harvey-Strominger model. The field theory side follows from the complex Sachdev-Ye-Kitaev model in the limit of large specific heat and vanishing compressibility. We derive the boundary action analogous to the Schwarzian as the key link between gravity and field theory sides and show that it coincides with a geometric action discovered recently by one of us [H. R. Afshar, Warped Schwarzian theory, J. High Energy Phys. 02 (2020) 126]
Intergenerational nutrition benefits of India's national school feeding program: Reality or a bridge too far?
Perturbed Sachdev-Ye-Kitaev Model: A Polaron in the Hyperbolic Plane
We study the Sachdev-Ye-Kitaev (SYK₄) model with a weak SYK₂ term of magnitude Γ beyond the simplest perturbative limit considered previously. For intermediate values of the perturbation strength, J/N ≪ Γ ≪ J/√N, fluctuations of the Schwarzian mode are suppressed, and the SYK₄ mean-field solution remains valid beyond the timescale t₀ ∼ N/J up to t∗∼J/Γ². The out-of-time-order correlation function displays at short time intervals exponential growth with maximal Lyapunov exponent 2πT, but its prefactor scales as T at low temperatures T ≤ Γ
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