9,027 research outputs found
ERTS Applications in earthquake research and mineral exploration in California
Examples that ERTS imagery can be effectively utilized to identify, locate, and map faults which show geomorphic evidence of geologically recent breakage are presented. Several important faults not previously known have been identified. By plotting epicenters of historic earthquakes in parts of California, Sonora, Mexico, Arizona, and Nevada, we found that areas known for historic seismicity are often characterized by abundant evidence of recent fault and crustal movements. There are many examples of seismically quiet areas where outstanding evidence of recent fault movements is observed. One application is clear: ERTS-1 imagery could be effectively utilized to delineate areas susceptible to earthquake recurrence which, on the basis of seismic data alone, may be misleadingly considered safe. ERTS data can also be utilized in planning new sites in the geophysical network of fault movement monitoring and strain and tilt measurements
Leaving Home Care: Decision Making, Risk Scenarios & Services Gaps in the Home Care System
Home and community-based services (HCBS) enable older and disabled adults to age-in-place in their homes and communities by helping them function independently for as long as possible (Grabowski et al., 2010; Wong & Silverstein, 2011). Previous studies well document that older adults prefer receiving HCBS rather than institutional care at a nursing home (e.g., Walker, 2010; Fox-Grage, Coleman, & Freiman, 2006). Medicaid is a major source of funding for long-term care. Currently, a large proportion of Medicaid funds in most states has been spent on institutional care (National Conference of State Legislatures & AARP, 2009), and older adults and their families have relied on nursing homes to be the provider of long-term care (Miller, Allen, & Mor, 2009). The purpose of this research is to provide additional insights to policy decision makers on the need to rebalance long-term care spending in Massachusetts by further exploring the reasons elder clients are terminated from home- and community-based care.
Care managers are key personnel in providing HCBS to elder clients and have unique insights regarding HCBS. This study builds on qualitative research conducted by Wong and Silverstein (2011) by further exploring the themes that emerged from the previous study related to termination triggers, gaps in HCBS, and the identification and roles of key decision makers in the termination process. In addition, this study examined risk scenarios that may trigger discharge from home- and community-based care programs into institutional settings
Towards a holographic marginal Fermi liquid
We present an infinite class of 2+1 dimensional field theories which, after
coupling to semi-holographic fermions, exhibit strange metallic behavior in a
suitable large limit. These theories describe lattices of hypermultiplet
defects interacting with parity-preserving supersymmetric Chern-Simons theories
with gauge groups at levels . They have dual
gravitational descriptions in terms of lattices of probe M2 branes in (for ) or probe D2 branes in (for ). We discuss several challenges one faces
in maintaining the success of these models at finite , including
backreaction of the probes in the gravity solutions and radiative corrections
in the weakly coupled field theory limit.Comment: 9 pages, RevTeX; v2, minor correction
Simple de Sitter Solutions
We present a framework for de Sitter model building in type IIA string
theory, illustrated with specific examples. We find metastable dS minima of the
potential for moduli obtained from a compactification on a product of two Nil
three-manifolds (which have negative scalar curvature) combined with
orientifolds, branes, fractional Chern-Simons forms, and fluxes. As a discrete
quantum number is taken large, the curvature, field strengths, inverse volume,
and four dimensional string coupling become parametrically small, and the de
Sitter Hubble scale can be tuned parametrically smaller than the scales of the
moduli, KK, and winding mode masses. A subtle point in the construction is that
although the curvature remains consistently weak, the circle fibers of the
nilmanifolds become very small in this limit (though this is avoided in
illustrative solutions at modest values of the parameters). In the simplest
version of the construction, the heaviest moduli masses are parametrically of
the same order as the lightest KK and winding masses. However, we provide a
method for separating these marginally overlapping scales, and more generally
the underlying supersymmetry of the model protects against large corrections to
the low-energy moduli potential.Comment: 37 pages, harvmac big, 4 figures. v3: small correction
The Scaling of the No Scale Potential and de Sitter Model Building
We propose a variant of the KKLT (A)dS flux vacuum construction which does
not require an antibrane to source the volume modulus. The strategy is to find
nonzero local minima of the no-scale potential in the complex structure and
dilaton directions in moduli space. The corresponding no-scale potential
expanded about this point sources the volume modulus in the same way as does
the antibrane of the KKLT construction. We exhibit explicit examples of such
nonzero local minima of the no-scale potential in a simple toroidal orientifold
model.Comment: 11 pages, harvmac big. v2: trivial typos fixe
On the Matrix Description of Calabi-Yau Compactifications
We point out that the matrix description of M-theory compactified on
Calabi-Yau threefolds is in many respects simpler than the matrix description
of a compactification. This is largely because of the differences between
D6 branes wrapped on Calabi-Yau threefolds and D6 branes wrapped on six-tori.
In particular, if we define the matrix theory following the prescription of Sen
and Seiberg, we find that the remaining degrees of freedom are decoupled from
gravity.Comment: 12 pages, harvmac big; comment on 4d N=1 theories change
Unitarity bounds and RG flows in time dependent quantum field theory
We generalize unitarity bounds on operator dimensions in conformal field
theory to field theories with spacetime dependent couplings. Below the energy
scale of spacetime variation of the couplings, their evolution can strongly
affect the physics, effectively shifting the infrared operator scaling and
unitarity bounds determined from correlation functions in the theory. We
analyze this explicitly for large- double-trace flows, and connect these to
UV complete field theories. One motivating class of examples comes from our
previous work on FRW holography, where this effect explains the range of
flavors allowed in the dual, time dependent, field theory.Comment: 38 page
Enhancement of the ferromagnetic order of graphite after sulphuric acid treatment
We have studied the changes in the ferromagnetic behavior of graphite powder
and graphite flakes after treatment with diluted sulphuric acid. We show that
this kind of acid treatment enhances substantially the ferromagnetic
magnetization of virgin graphite micrometer size powder as well as in graphite
flakes. The anisotropic magnetoresistance (AMR) amplitude at 300 K measured in
a micrometer size thin graphite flake after acid treatment reaches values
comparable to polycrystalline cobalt.Comment: 3.2 pages, 4 figure
Functional network changes and cognitive control in schizophrenia
Cognitive control is a cognitive and neural mechanism that contributes to managing the complex demands of day-to-day life. Studies have suggested that functional impairments in cognitive control associated brain circuitry contribute to a broad range of higher cognitive deficits in schizophrenia. To examine this issue, we assessed functional connectivity networks in healthy adults and individuals with schizophrenia performing tasks from two distinct cognitive domains that varied in demands for cognitive control, the RiSE episodic memory task and DPX goal maintenance task. We characterized general and cognitive control-specific effects of schizophrenia on functional connectivity within an expanded frontal parietal network (FPN) and quantified network topology properties using graph analysis. Using the network based statistic (NBS), we observed greater network functional connectivity in cognitive control demanding conditions during both tasks in both groups in the FPN, and demonstrated cognitive control FPN specificity against a task independent auditory network. NBS analyses also revealed widespread connectivity deficits in schizophrenia patients across all tasks. Furthermore, quantitative changes in network topology associated with diagnostic status and task demand were observed. The present findings, in an analysis that was limited to correct trials only, ensuring that subjects are on task, provide critical insights into network connections crucial for cognitive control and the manner in which brain networks reorganize to support such control. Impairments in this mechanism are present in schizophrenia and these results highlight how cognitive control deficits contribute to the pathophysiology of this illness
On the harmonic measure of stable processes
Using three hypergeometric identities, we evaluate the harmonic measure of a
finite interval and of its complementary for a strictly stable real L{\'e}vy
process. This gives a simple and unified proof of several results in the
literature, old and recent. We also provide a full description of the
corresponding Green functions. As a by-product, we compute the hitting
probabilities of points and describe the non-negative harmonic functions for
the stable process killed outside a finite interval
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