326,128 research outputs found
Is the incidence of dementia declining?
No full textAction 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
Sachdev–Ye–Kitaev model as Liouville quantum mechanics
No full textAbstractWe show that the proper inclusion of soft reparameterization modes in the Sachdev–Ye–Kitaev model of N randomly interacting Majorana fermions reduces its long-time behavior to that of Liouville quantum mechanics. As a result, all zero temperature correlation functions decay with the universal exponent ∝τ−3/2 for times larger than the inverse single particle level spacing τ≫NlnN. In the particular case of the single particle Green function this behavior is manifestation of the zero-bias anomaly, or scaling in energy as ϵ1/2. We also present exact diagonalization study supporting our conclusions
Spin liquid to spin glass crossover in the random quantum Heisenberg magnet
No full textWe study quantum SU() spins with all-to-all and random Heisenberg exchange interactions of root-mean-square strength . The model has a spin liquid ground state with the spinons obeying the equations of the Sachdev-Ye-Kitaev (SYK) model. Numerical studies of the SU(2) model with spins show spin glass order in the ground state, but also display SYK spin liquid behavior in the intermediate frequency spin spectrum. We employ a expansion to describe the crossover from fractionalized fermionic spinons to a confining spin glass state with weak spin glass order . The SYK spin liquid behavior persists down to a frequency , and for \omega < \omega_\ast, the spectral density is linear in , thus quenching the extensive zero temperature entropy of the spin liquid. The linear spectrum is qualitatively similar to that obtained earlier using bosonic spinons for large . We argue that the extensive SYK spin liquid entropy is transformed as to an extensive complexity of the spin glass state
Arterial stiffness, the brain and cognition: A systematic review
No full textAbstract not availableJoel Singer, Julian N. Trollor, Bernhard T. Baune, Perminder S. Sachdev, Evelyn Smit
Ultrapotent and broad neutralization of SARS-CoV-2 variants by modular, tetravalent, bi-paratopic antibodies
No full textNeutralizing antibodies (nAbs) that target the SARS-CoV-2 spike protein have received emergency use approval for treatment of COVID-19. However, with the emergence of variants of concern, there is a need for new treatment options. We report a format that enables modular assembly of bi-paratopic tetravalent nAbs with antigen-binding sites from two distinct nAbs. The tetravalent nAb purifies in high yield and exhibits biophysical characteristics that are comparable to those of clinically used therapeutic antibodies. The tetravalent nAb binds to the spike protein trimer at least 100-fold more tightly than bivalent IgGs (apparent K(D) < 1 pM) and neutralizes a broad array of SARS-CoV-2 pseudoviruses, chimeric viruses, and authentic viral variants with high potency. Together, these results establish the tetravalent diabody-Fc-Fab as a robust, modular platform for rapid production of drug-grade nAbs with potencies and breadth of coverage that greatly exceed those of conventional bivalent IgGs
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Nodal Quasiparticles and the Onset of Spin-Density-Wave-Order in Cuprate Superconductors
No full textWe present a theory for the onset of spin-density-wave order in the superconducting ground state of the cuprates. We compute the scaling dimensions of allowed perturbations of a “relativistic” fixed point with O(4) O(3) symmetry, including those associated with the fermionic nodal Bogoliubov quasiparticles. Analyses of up to six loops show that all perturbations with square lattice symmetry are likely irrelevant. We demonstrate that the fermion spectral functions are primarily damped by the coupling to fluctuations of a composite field with Ising nematic order. A number of other experimental implications are also discussed.PhysicsAuthor's Origina
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Non-pharmacological interventions in secondary schizophrenia
No full textSchizophrenia may not be a single disease, but the result of a diverse set of related conditions. Modern neuroscience is beginning to reveal some of the genetic and environmental underpinnings of schizophrenia; however, an approach less well travelled is to examine the medical disorders that produce symptoms resembling schizophrenia. This book is the first major attempt to bring together the diseases that produce what has been termed 'secondary schizophrenia'. International experts from diverse backgrounds ask the questions: does this medical disorder, or drug, or condition cause psychosis? If yes, does it resemble schizophrenia? What mechanisms form the basis of this relationship? What implications does this understanding have for aetiology and treatment? The answers are a feast for clinicians and researchers of psychosis and schizophrenia. They mark the next step in trying to meet the most important challenge to modern neuroscience – understanding and conquering this most mysterious of human diseases
- …
