528 research outputs found
Becoming deafblind: Negotiating a place in a hostile world
Doctor of PhilosophyThis study addresses the situation of adults who become deafblind. To date, their everday lives have received little attention in the research literature. Of the few studies conducted many involve surveys, the findings of which present the characteristics of people who are deafblind such as their rates of employment, need for support, or use of equipment. There are also a small number of qualitative studies that have explored the effects of having dual sensory impairment, and particularly in relation to communication and psycho-social wellbeing. Important as these research efforts have been, there is little empirical information available about the everyday lives of people who become deafblind and their concerns, nor any systematic attempt to theorise their experiences. There are however many personal anecdotes typically presented at conferences or through community publications and newsletters. This project aimed to redress the gap in the literature by developing a theoretical framework to explain the everyday experiences of adult who become deafblind. In doing so, it built upon the research and anecdotal literature with an overall purpose of presenting, through rigorous research, the experiences of adults who become deafblind and to do so within the broader discourse on disability and disablism. The study was informed by the social relational understanding of disability developed within the Nordic countries. Grounded theory was the method of choice to examine the lives of adults who become deafblind from their own perspective.Participant observation was employed through direct engagement in shared experiences with adults who have become deafblind both at a social group and via an e-mail list group. Mulitple in-depth interviews were undertaken both face to face and by e-mail with a smaller group of eight participants.The core finding from this study is that people who become deafblind are rendered interactionally powerless in a society predicated on seeing and hearing. The powerlessness that they experience comes from having this dual impairment in a world in which being able to see and hear are expected both in the physical and social environment. The inability of people who become deafblind to 'know and be' in the world in the same way as others results in them feeling, and experienceing, interactional powerlessness. In response, people who become deafblind actively engage in trying to minimise or remove their powerlessness. They do so by working to negotiate a place in this hostile world. They adopt four interrelated strategies, namely, doing things differently, managing support relationships, survivings others' perceptions and presenting sides of self.This study, with its central tenet that interactional powerlessness drives ongoing attempts to negotiate a place makes a theoretical contribution to understanding the experience of becoming deafblind. The findings support the concept of disbaility as social relational. Disability is not the same as the sensory impairment, rather it is expressed in the organisation of personal relations in society which render some more powerful than others and in this case, some less powerful due to their inability to use the natural means of communication of hearing and sight. Moreover, the study findings propose that professionals working with people with this dual sensory impairment must endeavour to reduce their part in the hostile world by providing information about options and support available; recognising the complexity of these adults support requirements; and considering the link between psycho-emotional issues and disablism. Further research is needed to understand empirically and theoretically the relative contribution of personal relationships vis a vis organisational or structural relationships in disabling people who become deafblind
Complementary vertices and adjacency testing in polytopes
Our main theoretical result is that, if a simple polytope has a pair of
complementary vertices (i.e., two vertices with no facets in common), then it
has at least two such pairs, which can be chosen to be disjoint. Using this
result, we improve adjacency testing for vertices in both simple and non-simple
polytopes: given a polytope in the standard form {x \in R^n | Ax = b and x \geq
0} and a list of its V vertices, we describe an O(n) test to identify whether
any two given vertices are adjacent. For simple polytopes this test is perfect;
for non-simple polytopes it may be indeterminate, and instead acts as a filter
to identify non-adjacent pairs. Our test requires an O(n^2 V + n V^2)
precomputation, which is acceptable in settings such as all-pairs adjacency
testing. These results improve upon the more general O(nV) combinatorial and
O(n^3) algebraic adjacency tests from the literature.Comment: 14 pages, 5 figures. v1: published in COCOON 2012. v2: full journal
version, which strengthens and extends the results in Section 2 (see p1 of
the paper for details
Rapid X-ray Variability of Seyfert 1 Galaxies
The rapid and seemingly random fluctuations in X-ray luminosity of Seyfert
galaxies provided early support for the standard model in which Seyferts are
powered by a supermassive black hole fed from an accretion disc. However, since
EXOSAT there has been little opportunity to advance our understanding of the
most rapid X-ray variability. Observations with XMM-Newton have changed this.
We discuss some recent results obtained from XMM-Newton observations of Seyfert
1 galaxies. Particular attention will be given to the remarkable similarity
found between the timing properties of Seyferts and black hole X-ray binaries,
including the power spectrum and the cross spectrum (time delays and
coherence), and their implications for the physical processes at work in
Seyferts.Comment: To appear in From X-ray Binaries to Quasars: Black Hole Accretion on
All Mass Scales, ed. T. J. Maccarone, R. P. Fender, and L. C. Ho (Dordrecht:
Kluwer
Semi- and Non-relativistic Limit of the Dirac Dynamics with External Fields
We show how to approximate Dirac dynamics for electronic initial states by
semi- and non-relativistic dynamics. To leading order, these are generated by
the semi- and non-relativistic Pauli hamiltonian where the kinetic energy is
related to and , respectively. Higher-order
corrections can in principle be computed to any order in the small parameter
v/c which is the ratio of typical speeds to the speed of light. Our results
imply the dynamics for electronic and positronic states decouple to any order
in v/c << 1.
To decide whether to get semi- or non-relativistic effective dynamics, one
needs to choose a scaling for the kinetic momentum operator. Then the effective
dynamics are derived using space-adiabatic perturbation theory by Panati et. al
with the novel input of a magnetic pseudodifferential calculus adapted to
either the semi- or non-relativistic scaling.Comment: 42 page
From Violation to Reconstruction: The Process of Self-Renewal Associated with Chronic Fatigue Syndrome
Chronic Fatigue Syndrome (CFS) is a contested condition that generates scepticism and occupies a marginalised position within medical and social contexts. The thesis examines the illness experiences, and specifically the experiences of self, for people affected with CFS. Using qualitative inquiry, a substantive theory related to the process of self-renewal and adaptation associated with CFS is explicated. The theory encompasses the trajectory of CFS from onset to chronicity, and in exceptional instances, recovery. Illness narratives were derived from in-depth, semi-structured interviews of 19 adults, including 16 people affected with, and 3 people recovered from, CFS. Data was coded and analysed using a grounded theory approach. Analysis generated two parallel narratives that defined the illness experience of CFS: the narrative of the illness biographies and the narrative of self, specifically the struggling and diminished self seeking renewal. The illness biographies encompassed the stories of symptoms and their explanations, the encounters that ensued and their contentious milieu. The narrative of self was the primary narrative. It articulated the negative consequences to self and personhood associated with CFS, named the Violation of Self, and the consequent efforts of participants to decrease the struggle and violation by use of the Guardian Response and the Reconstructing Response. The Guardian Response provided protection and self-reclamation. The Reconstructing Response fostered self-renewal and meaning. The two narratives were bridged by the threats of CFS. That is, the illness biographies were accompanied by threats of disruption related to chronic illness, and by threats of invalidation that arose from CFS as a contested condition. In turn, these threats provided the catalyst to the violation and responses as described in the narrative of self. Under different conditions the relative strengths of violation, guardianship or reconstruction fluctuated, and it was these fluctuations that presented the participants with the ongoing struggle of CFS
Spectral Properties of the Overlap Dirac Operator in QCD
We discuss the eigenvalue distribution of the overlap Dirac operator in
quenched QCD on lattices of size 8^{4}, 10^{4} and 12^{4} at \beta = 5.85 and
\beta = 6. We distinguish the topological sectors and study the distributions
of the leading non-zero eigenvalues, which are stereographically mapped onto
the imaginary axis. Thus they can be compared to the predictions of random
matrix theory applied to the \epsilon-expansion of chiral perturbation theory.
We find a satisfactory agreement, if the physical volume exceeds about (1.2
fm)^{4}. For the unfolded level spacing distribution we find an accurate
agreement with the random matrix conjecture on all volumes that we considered.Comment: 16 pages, 8 figures, final version published in JHE
Oral prednisolone suppresses skin inflammation in a healthy volunteer imiquimod challenge model
Imiquimod (IMQ) is a topical agent that induces local inflammation via the Toll-like receptor 7 pathway. Recently, an IMQ-driven skin inflammation model was developed in healthy volunteers for proof-of-pharmacology trials. The aim of this study was to profile the cellular, biochemical, and clinical effects of the marketed anti-inflammatory compound prednisolone in an IMQ model. This randomized, double-blind, placebo-controlled study was conducted in 24 healthy volunteers. Oral prednisolone (0.25 mg/kg/dose) or placebo (1:1) was administered twice daily for 6 consecutive days. Two days after treatment initiation with prednisolone or placebo, 5 mg imiquimod (IMQ) once daily for two following days was applied under occlusion on the tape-stripped skin of the back for 48 h in healthy volunteers. Non-invasive (imaging and biophysical) and invasive (skin punch biopsies and blister induction) assessments were performed, as well as IMQ ex vivo stimulation of whole blood. Prednisolone reduced blood perfusion and skin erythema following 48 h of IMQ application (95% CI [−26.4%, −4.3%], p = 0.0111 and 95% CI [−7.96, −2.13], p = 0.0016). Oral prednisolone suppressed the IMQ-elevated total cell count (95% CI [−79.7%, −16.3%], p = 0.0165), NK and dendritic cells (95% CI [−68.7%, −5.2%], p = 0.0333, 95% CI [−76.9%, −13.9%], p = 0.0184), and classical monocytes (95% CI [−76.7%, −26.6%], p = 0.0043) in blister fluid. Notably, TNF, IL-6, IL-8, and Mx-A responses in blister exudate were also reduced by prednisolone compared to placebo. Oral prednisolone suppresses IMQ-induced skin inflammation, which underlines the value of this cutaneous challenge model in clinical pharmacology studies of novel anti-inflammatory compounds. In these studies, prednisolone can be used as a benchmark.</p
Wetenschap met de ramen wijd open: tien lessen voor wie impact wil maken
In tien lessen geven door de wol geverfde sociale en geesteswetenschappers handvatten aan collega’s die impact willen maken met hun onderzoek. In een nieuwe brochure, een uitgave van de Sociaal-Wetenschappelijke Raad van de KNAW, pleiten ze voor meer waardering voor impact en geven ze praktische handvatten om aan de slag te gaan. Wetenschap met de ramen wijd open, tien lessen voor wie impact wil maken is een uitgave van de Sociaal-Wetenschappelijke Raad van de Koninklijke Nederlandse Akademie voor Wetenschappen (KNAW). De brochure is geschreven door Godfried Engbersen, Andrea Evers, Beatrice de Graaf, Paul ’t Hart, Anita Jansen, Lotte Jensen, Leo Lucassen en Maarten Prak, allen hoogleraar in de sociale of geesteswetenschappen. De gedrukte brochure wordt in het Nederlands verspreid over alle faculteiten
Application of heavy-quark effective theory to lattice QCD: III. Radiative corrections to heavy-heavy currents
We apply heavy-quark effective theory (HQET) to separate long- and
short-distance effects of heavy quarks in lattice gauge theory. In this paper
we focus on flavor-changing currents that mediate transitions from one heavy
flavor to another. We stress differences in the formalism for heavy-light
currents, which are discussed in a companion paper, showing how HQET provides a
systematic matching procedure. We obtain one-loop results for the matching
factors of lattice currents, needed for heavy-quark phenomenology, such as the
calculation of zero-recoil form factors for the semileptonic decays . Results for the Brodsky-Lepage-Mackenzie scale are also
given.Comment: 35 pages, 17 figures. Program LatHQ2QCD to compute matching one-loop
coefficients available at http://theory.fnal.gov/people/kronfeld/LatHQ2QCD
Chiral three-nucleon forces and bound excited states in neutron-rich oxygen isotopes
We study the spectra of neutron-rich oxygen isotopes based on chiral two- and
three-nucleon interactions. First, we benchmark our many-body approach by
comparing ground-state energies to coupled-cluster results for the same
two-nucleon interaction, with overall good agreement. We then calculate bound
excited states in 21,22,23O, focusing on the role of three-nucleon forces, in
the standard sd shell and an extended sdf7/2p3/2 valence space. Chiral
three-nucleon forces provide important one- and two-body contributions between
valence neutrons. We find that both these contributions and an extended valence
space are necessary to reproduce key signatures of novel shell evolution, such
as the N = 14 magic number and the low-lying states in 21O and 23O, which are
too compressed with two-nucleon interactions only. For the extended space
calculations, this presents first work based on nuclear forces without
adjustments. Future work is needed and open questions are discussed.Comment: 6 pages, 4 figures, published versio
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