2,674 research outputs found
Supraorbital transcutaneous neurostimulation has sedative effects in healthy subjects
Transcutaneous neurostimulation (TNS) at extracephalic sites is a well known treatment of pain. Thanks to recent technical progress, the Cefaly® device now also allows supraorbital TNS. During observational clinical studies, several patients reported decreased vigilance or even sleepiness during a session of supraorbital TNS. We decided therefore to explore in more detail the potential sedative effect of supraorbital TNS, using standardized psychophysical tests in healthy volunteers.Clinical TrialJournal Articleinfo:eu-repo/semantics/publishe
Ultra-light Axions: Degeneracies with Massive Neutrinos and Forecasts for Future Cosmological Observations
A generic prediction of string theory is the existence of many axion fields.
It has recently been argued that many of these fields should be light and, like
the well known QCD axion, lead to observable cosmological consequences. In this
paper we study in detail the effect of the so-called string axiverse on large
scale structure, focusing on the morphology and evolution of density
perturbations, anisotropies in the cosmic microwave background and weak
gravitational lensing of distant galaxies. We quantify specific effects that
will arise from the presence of the axionic fields and highlight possible
degeneracies that may arise in the presence of massive neutrinos. We take
particular care understanding the different physical effects and scales that
come into play. We then forecast how the string axiverse may be constrained and
show that with a combination of different observations, it should be possible
to detect a fraction of ultralight axions to dark matter of a few percent.Comment: 24 pages, 16 figures, this version: corrected typos, some comments
added, matches published versio
Mixed pairing symmetry in \kappa-(BEDT-TTF)_2 X organic superconductors from ultrasonic velocity measurements
Discontinuities in elastic constants are detected at the superconducting
transition of layered organic conductors \kappa-(BEDT-TTF)_{2}X by longitudinal
and transverse ultrasonic velocity measurements. Symmetry arguments show that
discontinuities in shear elastic constants can be explained in the orthorhombic
compound only if the superconducting order parameter has a mixed character that
can be of two types, either A_{1g}+B_{1g} or B_{2g}+B_{3g} in the
classification of irreducible representations of the orthorhombic point group
D_{2h}. Consistency with other measurements suggests that the A_{1g}+B_{1g}
(d_{xy}+d_{z(x+y)}) possibility is realized. Such clear symmetry-imposed
signatures of mixed order parameters have not been observed in other
superconducting compounds.Comment: 5 pages, LaTeX,3 figure
Disruption of information processing in schizophrenia: The time perspective
AbstractWe review studies suggesting time disorders on both automatic and subjective levels in patients with schizophrenia. Patients have difficulty explicitly discriminating between simultaneous and asynchronous events, and ordering events in time. We discuss the relationship between these difficulties and impairments on a more elementary level. We showed that for undetectable stimulus onset asynchronies below 20ms, neither patients nor controls merge events in time, as previously believed. On the contrary, subjects implicitly distinguish between events even when evaluating them to be simultaneous. Furthermore, controls privilege the last stimulus, whereas patients seem to stay stuck on the first stimulus when asynchronies are sub-threshold. Combining previous results shows this to be true for patients even for asynchronies as short as 8ms. Moreover, this peculiarity predicts difficulties with detecting asynchronies longer than 50ms, suggesting an impact on the conscious ability to time events. Difficulties on the subjective level are also correlated with clinical disorganization. The results are interpreted within the framework of predictive coding which can account for an implicit ability to update events. These results complement a range of other results, by suggesting a difficulty with binding information in time as well as space, and by showing that information processing lacks continuity and stability in patients. The time perspective may help bridge the gap between cognitive impairments and clinical symptoms, by showing how the innermost structure of thought and experience is disrupted
When a tree dies in the forest : scaling climate-driven tree mortality to ecosystem water and carbon fluxes
Altres ajuts: COST FP1106 network STReESS.Drought- and heat-driven tree mortality, along with associated insect outbreaks, have been observed globally in recent decades and are expected to increase in future climates. Despite its potential to profoundly alter ecosystem carbon and water cycles, how tree mortality scales up to ecosystem functions and fluxes is uncertain. We describe a framework for this scaling where the effects of mortality are a function of the mortality attributes, such as spatial clustering and functional role of the trees killed, and ecosystem properties, such as productivity and diversity. We draw upon remote-sensing data and ecosystem flux data to illustrate this framework and place climate-driven tree mortality in the context of other major disturbances. We find that emerging evidence suggests that climate-driven tree mortality impacts may be relatively small and recovery times are remarkably fast (~4 years for net ecosystem production). We review the key processes in ecosystem models necessary to simulate the effects of mortality on ecosystem fluxes and highlight key research gaps in modeling. Overall, our results highlight the key axes of variation needed for better monitoring and modeling of the impacts of tree mortality and provide a foundation for including climate-driven tree mortality in a disturbance framework
Immigrant community integration in world cities
As a consequence of the accelerated globalization process, today major cities
all over the world are characterized by an increasing multiculturalism. The
integration of immigrant communities may be affected by social polarization and
spatial segregation. How are these dynamics evolving over time? To what extent
the different policies launched to tackle these problems are working? These are
critical questions traditionally addressed by studies based on surveys and
census data. Such sources are safe to avoid spurious biases, but the data
collection becomes an intensive and rather expensive work. Here, we conduct a
comprehensive study on immigrant integration in 53 world cities by introducing
an innovative approach: an analysis of the spatio-temporal communication
patterns of immigrant and local communities based on language detection in
Twitter and on novel metrics of spatial integration. We quantify the "Power of
Integration" of cities --their capacity to spatially integrate diverse
cultures-- and characterize the relations between different cultures when
acting as hosts or immigrants.Comment: 13 pages, 5 figures + Appendi
A systematic variation of the stellar initial mass function in early-type galaxies
Much of our knowledge of galaxies comes from analysing the radiation emitted
by their stars. It depends on the stellar initial mass function (IMF)
describing the distribution of stellar masses when the population formed.
Consequently knowledge of the IMF is critical to virtually every aspect of
galaxy evolution. More than half a century after the first IMF determination,
no consensus has emerged on whether it is universal in different galaxies.
Previous studies indicated that the IMF and the dark matter fraction in galaxy
centres cannot be both universal, but they could not break the degeneracy
between the two effects. Only recently indications were found that massive
elliptical galaxies may not have the same IMF as our Milky Way. Here we report
unambiguous evidence for a strong systematic variation of the IMF in early-type
galaxies as a function of their stellar mass-to-light ratio, producing
differences up to a factor of three in mass. This was inferred from detailed
dynamical models of the two-dimensional stellar kinematics for the large
Atlas3D representative sample of nearby early-type galaxies spanning two orders
of magnitude in stellar mass. Our finding indicates that the IMF depends
intimately on a galaxy's formation history.Comment: 4 pages, 2 figures, LaTeX. Accepted for publication as a Nature
Letter. More information about our Atlas3D project is available at
http://purl.org/atlas3
2001 AAPP Monograph Series
The African American Professors Program (AAPP) at the University of South Carolina is pleased to produce this premier edition of its annual monograph series. It is fitting that the program assume a leadership role in promoting scholarly products that will prove to be useful in future research efforts by faculty and students in higher education.
Scholars who have contributed manuscripts for this monograph are to be commended for adding this additional responsibility to their academic workload. Writing across disciplines adds to the intellectual diversity of these papers. From neophytes, relatively speaking, to an array of very experienced individuals, the chapters have been researched and, comprehensively, written.
AAPP was created in 1997 under the leadership of Drs. Aretha B. Pigford and Leonard 0. Pellicer, Department of Educational Leadership and Policies. It was designed to address the underrepresentation of African American professors on college and university campuses. Its mission is to expand the pool of these professors in critical academic and research areas. Sponsored by the University of South Carolina, the W. K. Kellogg Foundation, and the South Carolina General Assembly, the program recruits students with bachelor\u27s, master\u27s, and doctoral degrees for disciplines in which African Americans, currently, are underrepresented.
An important component of the program is the mentoring experience that is provided. Each student is assigned to a mentor professor who guides the student through a selected academic program and provides various learning experiences. When possible, the mentor serves as chair of the student\u27s doctoral committee. The mentor, also, provides opportunities for the student to team teach, conduct research, and co-author publications. Students have opportunities to attend committee, faculty, and professional meetings, as well as engage in a range of activities that characterize professional life in academia. Scholars enrolled in the program, also, are involved in programmatic and institutional workshops, independent research, and program development.
The establishment or genesis of this monograph series is seen as responding to an opportunity to be sensitive to an academic expectation of graduates as they pursue career placement and, also, one that allows for the dissemination of AAPP products to a broader community. We hope that you, likewise, will read this premier monograph of the African American Professors Program with enthusiasm or enlightenment.
John McFadden, Ph.D.
The Benjamin Elijah Mays Professor
Director, African American Professors Program
University of South Carolinahttps://scholarcommons.sc.edu/mcfadden_monographs/1005/thumbnail.jp
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