676 research outputs found
The Role of Prescription Trends in the Opioid Epidemic and the Factors that Affect Physician Prescriptions
Every day, more than 90 Americans die as a result of opioid overdose (NIH, 2017a), and opioid overdoses have quadrupled since 1999 (CDC, 2016). Opioids are best described as a class of drug that includes synthetic versions, such as fentanyl, the commonly known illegal drug, heroin, and prescribed medications such as oxycodone (OxyContin®) and hydrocodone (Vicodin®; NIH, 2017b). Opioids directly activate the analgesia, or pain relieving portion of the brain as well as the reward region (Volkow & McLellan, 2016). This makes the drug effective for reducing pain as well as giving the body a sense of reward. However, the drug manipulates the reward system by building a learned association between taking the drug and the satisfactory effect received from the drug (Volkow & McLellan, 2016). This learned association puts the patient or user at risk for misuse of the drug, making opioid prescribing difficult for physicians. Other factors affecting opioid prescribing are racial disparities, patient-physician mistrust, pain perception, and the difference between acute and chronic pain (Mathur, Richeson, Paice, Muzyka, & Chiao 2014; Volkow & McLellan, 2016). The purpose of this article is to explore the factors that affect physicians’ decisions to prescribe opioids, and to examine how prescription trends influence the opioid epidemic
Deciding Finiteness for Matrix Groups Over Function Fields
Let S be any finite subset GLn(F(t)) where F is a field. In this paper we give algorithms to decide if the group generated by S is finite. In the case of characteristic zero, slight modifications of earlier work of Babai, Beals and Rockmore [1] give polynomial time deterministic algorithms to solve this problem. The case of positive characteristic turns out to be more subtle and our algorithms depend on a structure theorem proved here, generalizing a theorem of Weil. We also present a fairly detailed analysis of the size of finite subgroups in this case and give bounds which depend upon the number of generators. To this end we also introduce the notion of the diameter of a finitely generated algebra and derive some upper bounds related to this quantity. In positive characteristic the deterministic algorithms we present are exponential. A randomized algorithm based on ideas of the Meat-Axe is also given. While not provably efficient, the success of the Meat-Axe suggests the randomized algorithm will be useful
Effects of Carbohydrates on Landing Mechanics and Postural Stability During Intermittent High-Intensity Exercise to Fatigue
Please refer to the pdf version of the abstract located adjacent to the title
Inverse problems associated with integrable equations of Camassa-Holm type; explicit formulas on the real axis, I
The inverse problem which arises in the Camassa--Holm equation is revisited
for the class of discrete densities. The method of solution relies on the use
of orthogonal polynomials. The explicit formulas are obtained directly from the
analysis on the real axis without any additional transformation to a "string"
type boundary value problem known from prior works
Neumark Operators and Sharp Reconstructions, the finite dimensional case
A commutative POV measure with real spectrum is characterized by the
existence of a PV measure (the sharp reconstruction of ) with real
spectrum such that can be interpreted as a randomization of . This paper
focuses on the relationships between this characterization of commutative POV
measures and Neumark's extension theorem. In particular, we show that in the
finite dimensional case there exists a relation between the Neumark operator
corresponding to the extension of and the sharp reconstruction of . The
relevance of this result to the theory of non-ideal quantum measurement and to
the definition of unsharpness is analyzed.Comment: 37 page
Efficient quantum algorithms for simulating sparse Hamiltonians
We present an efficient quantum algorithm for simulating the evolution of a
sparse Hamiltonian H for a given time t in terms of a procedure for computing
the matrix entries of H. In particular, when H acts on n qubits, has at most a
constant number of nonzero entries in each row/column, and |H| is bounded by a
constant, we may select any positive integer such that the simulation
requires O((\log^*n)t^{1+1/2k}) accesses to matrix entries of H. We show that
the temporal scaling cannot be significantly improved beyond this, because
sublinear time scaling is not possible.Comment: 9 pages, 2 figures, substantial revision
On an inverse problem for anisotropic conductivity in the plane
Let be a bounded domain with smooth
boundary and a smooth anisotropic conductivity on .
Starting from the Dirichlet-to-Neumann operator on
, we give an explicit procedure to find a unique domain
, an isotropic conductivity on and the boundary
values of a quasiconformal diffeomorphism which
transforms into .Comment: 9 pages, no figur
The inverse spectral problem for the discrete cubic string
Given a measure on the real line or a finite interval, the "cubic string"
is the third order ODE where is a spectral parameter. If
equipped with Dirichlet-like boundary conditions this is a nonselfadjoint
boundary value problem which has recently been shown to have a connection to
the Degasperis-Procesi nonlinear water wave equation. In this paper we study
the spectral and inverse spectral problem for the case of Neumann-like boundary
conditions which appear in a high-frequency limit of the Degasperis--Procesi
equation. We solve the spectral and inverse spectral problem for the case of
being a finite positive discrete measure. In particular, explicit
determinantal formulas for the measure are given. These formulas generalize
Stieltjes' formulas used by Krein in his study of the corresponding second
order ODE .Comment: 24 pages. LaTeX + iopart, xypic, amsthm. To appear in Inverse
Problems (http://www.iop.org/EJ/journal/IP
Scalability of quantum computation with addressable optical lattices
We make a detailed analysis of error mechanisms, gate fidelity, and
scalability of proposals for quantum computation with neutral atoms in
addressable (large lattice constant) optical lattices. We have identified
possible limits to the size of quantum computations, arising in 3D optical
lattices from current limitations on the ability to perform single qubit gates
in parallel and in 2D lattices from constraints on laser power. Our results
suggest that 3D arrays as large as 100 x 100 x 100 sites (i.e.,
qubits) may be achievable, provided two-qubit gates can be performed with
sufficiently high precision and degree of parallelizability. Parallelizability
of long range interaction-based two-qubit gates is qualitatively compared to
that of collisional gates. Different methods of performing single qubit gates
are compared, and a lower bound of is determined on the
error rate for the error mechanisms affecting Cs in a blue-detuned
lattice with Raman transition-based single qubit gates, given reasonable limits
on experimental parameters.Comment: 17 pages, 5 figures. Accepted for publication in Physical Review
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