887 research outputs found
Impending carotid blowout stabilization using an LT-D tube
Adequate stabilization of a patient presenting with a carotid blowout is one of the most challenging issues an on-call ENT surgeon can be confronted with. Reducing the bleeding and securing the airway are essential before more definitive management. We present the case of a 72-year-old patient with head and neck cancer who arrived at the emergency room with a carotid blowout and who was successfully stabilized using a King LT-D ventilation tube
Treatment of head and neck cancer with photodynamic therapy: results after one year
Photodynamic therapy (PDT) is a new and promising treatment modality for the treatment of malignant disease. This paper reports the preliminary experience of our group in the use of this therapy for the treatment of tumours arising in the head and neck. The majority of treatments in these cases have used a second generation systemic photosensitizer, meta-tetrahydroxyphenylchlorin (m-THPC). Two other cases were treated with either Photofrin 2 (a first generation systemic sensitizer) or with the topical photosensitizer, delta-aminolaevulinic acid (delta-ALA).The initial results have been encouraging with good clinical responses evident in patients presenting with a variety of differing tumour types. We feel there is now sufficient evidence of the efficacy of this treatment to warrant a multicentre prospective study into the treatment of early head and neck cancer with PDT
Davidsonian semantic theory and cognitive science of religion
This article investigates the extent to which the cognitive science of religion (CSR) and Donald Davidson’s semantic holism (DSH) harmonize. We first characterize CSR, philosophical
semantics (and more specifically DSH). We then note a prima facie tension between CSR
and DSH’s view of First-Person Authority (that we know what is meant when we speak in a
way that we do not when others speak). If CSR is correct that the causes of religious belief
are located in cognitive processes in the mind/brain, then religious insiders might have no
idea what they are talking about: only the scholar of CSR would have a chance of knowing
what they ‘really’ mean. The article argues that the resolution to this problem is to take
seriously DSH’s rejection of semantic bifurcation, specifically rejecting the idea that religious and non-religious language can be sharply distinguished. We conclude by supporting
the following claims: (i) common cognitive neural/psychological processes are explanatorily
relevant in proposed meaning-theories for any discourse, and (ii) those processes need
semantic supplementation with reference to external and naturalistic factors (biological,
cultural, environmental etc.)
Coupling of effective one-dimensional two-level atoms to squeezed light
A cavity QED system is analyzed which duplicates the dynamics of a two-level
atom in free space interacting exclusively with broadband squeezed light. We
consider atoms in a three or four-level Lambda-configuration coupled to a
high-finesse optical cavity which is driven by a squeezed light field. Raman
transitions are induced between a pair of stable atomic ground states via the
squeezed cavity mode and coherent driving fields. An analysis of the reduced
master equation for the atomic ground states shows that a three-level atomic
system has insufficient parameter flexibility to act as an effective two-level
atom interacting exclusively with a squeezed reservoir. However, the inclusion
of a fourth atomic level, coupled dispersively to one of the two ground states
by an auxiliary laser field, introduces an extra degree of freedom and enables
the desired interaction to be realised. As a means of detecting the reduced
quadrature decay rate of the effective two-level system, we examine the
transmission spectrum of a weak coherent probe field incident upon the cavity
Spatiotemporal Fluctuation Induced Transition in a Tumor Model with Immune Surveillance
We report on a simple model of spatial extend anti-tumor system with a
fluctuation in growth rate, which can undergo a nonequilibrium phase
transition. Three states as excited, sub-excited and non-excited states of a
tumor are defined to describe its growth. The multiplicative noise is found to
be double-face: The positive effect on a non-excited tumor and the negative
effect on an excited tumor.Comment: 8pages,5figure
Comparing comparison: Smith and Davidson
Nos últimos anos, vários autores têm criticado a comparação, como método na ciência da religião. Grande parte da discussão aborda o que chamamos da dilema da comparação religiosa: ou as semelhanças entre os casos comparados são reais e as diferenças acidentais, ou as diferenças são reais e as semelhanças meramente aparentes. No primeiro caso, o ato da comparação impõe semelhanças de uma maneira artificial, privilegiando erroneamente uma das coisas a serem comparadas, o que pressupõe uma visão essencialista, afirmando que as suas caracterÃsticas servem como medida de todo caso comparável. No segundo caso, as diferenças entre os casos a serem comparados são vistas como uma barreira insuperável, minando a própria premissa da comparação. Argumentamos que este aparente dilema pressupõe uma concepção representativa do significado, ou seja, que a comparação tem como meta descobrir qual tipo de coisa é representada pelos casos que estão sendo comparados. Entretanto, existem outras concepções do significado que podem potencialmente evitar ou resolver o dilema, reorientando a concepção básica de comparação, ao invés de entrar em detalhes dos recentes debates crÃticos. Este artigo afirma que o interpretarismo, uma abordagem do significado associada ao filósofo Donald Davidson, faz exatamente isso. JZ Smith não adotou explicitamente uma teoria semântica. Mas demonstramos que todos os seus principais elementos em seu trabalho de comparação se sustentam na base de uma visão interpretarista. As obras de Smith representam um modelo rico e detalhado de como a comparação prossegue sob uma semântica interpretativa. Este artigo tem duas implicações importantes para o estudo da religião. Primeiro, ela dissolve o dilema da comparação religiosa, sugerindo uma base teórica e metodológica mais firme para estudos comparativos. Segundo, sublinha que o trabalho de Smith serve como um modelo poderoso e prático do método comparativo, construÃdo a partir desta base. Como corolário, oferece um benefÃcio colateral interdisciplinar: a leitura de Smith à luz de Davidson também faz contribuições importantes para a filosofia da linguagem
Non-Markovian Quantum Trajectories of Many-Body Quantum Open Systems
A long-standing open problem in non-Markovian quantum state diffusion (QSD)
approach to open quantum systems is to establish the non-Markovian QSD
equations for multiple qubit systems. In this paper, we settle this important
question by explicitly constructing a set of exact time-local QSD equations for
-qubit systems. Our exact time-local (convolutionless) QSD equations have
paved the way towards simulating quantum dynamics of many-body open systems
interacting with a common bosonic environment. The applicability of this
multiple-qubit stochastic equation is exemplified by numerically solving
several quantum open many-body systems concerning quantum coherence dynamics
and dynamical control.Comment: 8 pages, 2 figures. manuscript revised and reference update
Detailed study of dissipative quantum dynamics of K-2 attached to helium nanodroplets
We thoroughly investigate vibrational quantum dynamics of dimers attached to
He droplets motivated by recent measurements with K-2 [1]. For those
femtosecond pump-probe experiments, crucial observed features are not
reproduced by gas phase calculations but agreement is found using a description
based on dissipative quantum dynamics, as briefly shown in [2]. Here we present
a detailed study of the influence of possible effects induced by the droplet.
The helium droplet causes electronic decoherence, shifts of potential surfaces,
and relaxation of wave packets in attached dimers. Moreover, a realistic
description of (stochastic) desorption of dimers off the droplet needs to be
taken into account. Step by step we include and study the importance of these
effects in our full quantum calculation. This allows us to reproduce and
explain all major experimental findings. We find that desorption is fast and
occurs already within 2-10 ps after electronic excitation. A further finding is
that slow vibrational motion in the ground state can be considered
frictionless.Comment: 17 pages, 5 figure
Quantum state transfer and entanglement distribution among distant nodes in a quantum network
We propose a scheme to utilize photons for ideal quantum transmission between
atoms located at spatially-separated nodes of a quantum network. The
transmission protocol employs special laser pulses which excite an atom inside
an optical cavity at the sending node so that its state is mapped into a
time-symmetric photon wavepacket that will enter a cavity at the receiving node
and be absorbed by an atom there with unit probability. Implementation of our
scheme would enable reliable transfer or sharing of entanglement among
spatially distant atoms.Comment: 4 pages, 3 postscript figure
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