360 research outputs found
Clinical Social Work and the Biomedical Industrial Complex
This article examines how the biomedical industrial complex has ensnared social work within a foreign conceptual and practice model that distracts clinical social workers from the special assistance that they can provide for people with mental distress and misbehavior. We discuss: (1) social work\u27s assimilation of psychiatric perspectives and practices during its pursuit of professional status; (2) the persistence of psychiatric hospitalization despite its coercive methods, high cost, and doubtful efficacy; (3) the increasing reliance on the Diagnostic and Statistical Manual of Mental Disorders, despite its widely acknowledged scientific frailty; and (4) the questionable contributions of psychoactive drugs to clinical mental health outcomes and their vast profits for the pharmaceutical industry, using antipsychotic drugs as a case example. We review a number of promising social work interventions overshadowed by the biomedical approach. We urge social work and other helping professions to exercise intellectual independence from the reigning paternalistic drug-centered biomedical ideology in mental health and to rededicate themselves to the supportive, educative, and problem-solving methods unique to their disciplines
Approximation of corner polyhedra with families of intersection cuts
We study the problem of approximating the corner polyhedron using
intersection cuts derived from families of lattice-free sets in .
In particular, we look at the problem of characterizing families that
approximate the corner polyhedron up to a constant factor, which depends only
on and not the data or dimension of the corner polyhedron. The literature
already contains several results in this direction. In this paper, we use the
maximum number of facets of lattice-free sets in a family as a measure of its
complexity and precisely characterize the level of complexity of a family
required for constant factor approximations. As one of the main results, we
show that, for each natural number , a corner polyhedron with basic
integer variables and an arbitrary number of continuous non-basic variables is
approximated up to a constant factor by intersection cuts from lattice-free
sets with at most facets if and that no such approximation is
possible if . When the approximation factor is allowed to
depend on the denominator of the fractional vertex of the linear relaxation of
the corner polyhedron, we show that the threshold is versus .
The tools introduced for proving such results are of independent interest for
studying intersection cuts
Subtropical Real Root Finding
We describe a new incomplete but terminating method for real root finding for
large multivariate polynomials. We take an abstract view of the polynomial as
the set of exponent vectors associated with sign information on the
coefficients. Then we employ linear programming to heuristically find roots.
There is a specialized variant for roots with exclusively positive coordinates,
which is of considerable interest for applications in chemistry and systems
biology. An implementation of our method combining the computer algebra system
Reduce with the linear programming solver Gurobi has been successfully applied
to input data originating from established mathematical models used in these
areas. We have solved several hundred problems with up to more than 800000
monomials in up to 10 variables with degrees up to 12. Our method has failed
due to its incompleteness in less than 8 percent of the cases
Sparsity of integer solutions in the average case
We examine how sparse feasible solutions of integer programs are, on average. Average case here means that we fix the constraint matrix and vary the right-hand side vectors. For a problem in standard form with m equations, there exist LP feasible solutions with at most m many nonzero entries. We show that under relatively mild assumptions, integer programs in standard form have feasible solutions with O(m) many nonzero entries, on average. Our proof uses ideas from the theory of groups, lattices, and Ehrhart polynomials. From our main theorem we obtain the best known upper bounds on the integer Carathéodory number provided that the determinants in the data are small
On the relationship between standard intersection cuts, lift-and-project cuts, and generalized intersection cuts
We examine the connections between the classes of cuts in the title. We show that lift-and-project (L&P) cuts from a given disjunction are equivalent to generalized intersection cuts from the family of polyhedra obtained by taking positive combinations of the complements of the inequalities of each term of the disjunction. While L&P cuts from split disjunctions are known to be equivalent to standard intersection cuts (SICs) from the strip obtained by complementing the terms of the split, we show that L&P cuts from more general disjunctions may not be equivalent to any SIC. In particular, we give easily verifiable necessary and sufficient conditions for a L&P cut from a given disjunction D to be equivalent to a SIC from the polyhedral counterpart of D. Irregular L&P cuts, i.e. those that violate these conditions, have interesting properties. For instance, unlike the regular ones, they may cut off part of the corner polyhedron associated with the LP solution from which they are derived. Furthermore, they are not exceptional: their frequency exceeds that of regular cuts. A numerical example illustrates some of the above properties. © 2016 Springer-Verlag Berlin Heidelberg and Mathematical Optimization Societ
National institutional systems’ hybridisation through interdependence. The case of EU-Russia gas relations
International audienceThe interdependencies between the EU and its external natural gas suppliers and Russia question the transformative impact of interdependence linked to hybridization processes. Our approach combines theories of institutional change, and French Regulation Theory. These approaches lead to a new look to characterize the way in which the confrontation of two regulatory systems (EU and Russia) is resolved today. The importance of the European market leads however to an adaptation of the Russian governance model for gas exchanges. But it also implies a transformation of the European model. The competitive norm acts as a lever to bring about hybridization of regulations in the Russian gas sector and EU energy policy
On the statistical detection of propagating waves in polar coronal holes
Waves are important for the heating of the solar corona and the acceleration
of the solar wind. We have examined a long spectral time series of a northern
coronal hole observed on the 20th October 1996, with the SUMER spectrometer
onboard SoHO. The observations were obtained in a transition region N IV 765 A
line and in a low coronal Ne VIII 770 A line. Our observations indicate the
presence of compressional waves with periods of ~25 min. Using Fourier
techniques, we measured the phase delays between intensity as well as velocity
oscillations in the two chosen lines. From this we are able to measure the
travel time of the propagating oscillations and, hence, the propagation speeds
of the waves producing the oscillations. We found that there is a difference in
the nature of the propagation in bright ('network') and dark ('internetwork')
regions with the latter sometimes showing evidence for downwardly propagating
waves that is not seen in the former. As, in all cases, the measured
propagation speeds are subsonic, we concluded that the detected waves are slow
magnetoacoustic in nature.Comment: 7 pages, 7 figure
Antiferromagnetic spintronics
Antiferromagnetic materials are magnetic inside, however, the direction of
their ordered microscopic moments alternates between individual atomic sites.
The resulting zero net magnetic moment makes magnetism in antiferromagnets
invisible on the outside. It also implies that if information was stored in
antiferromagnetic moments it would be insensitive to disturbing external
magnetic fields, and the antiferromagnetic element would not affect
magnetically its neighbors no matter how densely the elements were arranged in
a device. The intrinsic high frequencies of antiferromagnetic dynamics
represent another property that makes antiferromagnets distinct from
ferromagnets. The outstanding question is how to efficiently manipulate and
detect the magnetic state of an antiferromagnet. In this article we give an
overview of recent works addressing this question. We also review studies
looking at merits of antiferromagnetic spintronics from a more general
perspective of spin-ransport, magnetization dynamics, and materials research,
and give a brief outlook of future research and applications of
antiferromagnetic spintronics.Comment: 13 pages, 7 figure
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