420 research outputs found
Towards a software profession
An increasing number of programmers have attempted to change their image. They have made it plain that they wish not only to be taken seriously, but they also wish to be regarded as professionals. Many programmers now wish to referred to as software engineers. If programmers wish to be considered professionals in every sense of the word, two obstacles must be overcome: the inability to think of software as a product, and the idea that little or no skill is required to create and handle software throughout its life cycle. The steps to be taken toward professionalization are outlined along with recommendations
Object-oriented requirements analysis: A quick tour
Of all the approaches to software development, an object-oriented approach appears to be both the most beneficial and the most popular. The description of the object-oriented approach is presented in the form of the view graphs
Instability of misoprostol tablets stored outside the blister: a potential serious concern for clinical outcome in medical abortion
Misoprostol (Cytotec) is recognised to be effective for many gynaecological indications including termination of pregnancy, management of miscarriage and postpartum haemorrhage. Although not licensed for such indications, it has been used for these purposes by millions of women throughout the world. Misoprostol tablets are most often packaged as multiple tablets within an aluminium strip, each within an individual alveolus. When an alveolus is opened, tablets will be exposed to atmospheric conditions
Isospectrality in Chaotic Billiards
We consider a modification of isospectral cavities whereby the classical
dynamics changes from pseudointegrable to chaotic. We construct an example
where we can prove that isospectrality is retained. We then demonstrate this
explicitly in microwave resonators.Comment: 5 pages, 7 figure
Berry effect in acoustical polarization transport in phononic crystals
We derive the semiclassical equations of motion of a transverse acoustical
wave packet propagating in a phononic crystal subject to slowly varying
perturbations. The formalism gives rise to Berry effect terms in the equations
of motion, manifested as the Rytov polarization rotation law and the
polarization-dependent Hall effect. We show that the formalism is also
applicable to the case of non-periodic inhomogeneous media, yielding explicit
expressions for the Berry effect terms.Comment: To appear in JETP Let
The Structure of the Vortex Liquid at the Surface of a Layered Superconductor
A density-functional approach is used to calculate the inhomogeneous vortex
density distribution in the flux liquid phase at the planar surface of a
layered superconductor, where the external magnetic field is perpendicular to
the superconducting layers and parallel to the surface. The interactions with
image vortices are treated within a mean field approximation as a functional of
the vortex density. Near the freezing transition strong vortex density
fluctuations are found to persist far into the bulk liquid. We also calculate
the height of the Bean-Livingston surface barrier.Comment: 8 pages, RevTeX, 2 figure
In Vivo Measurement of Hippocampal GABAA/cBZR Density with [18F]-Flumazenil PET for the Study of Disease Progression in an Animal Model of Temporal Lobe Epilepsy
PURPOSE: Imbalance of inhibitory GABAergic neurotransmission has been proposed to play a role in the pathogenesis of temporal lobe epilepsy (TLE). This study aimed to investigate whether [(18)F]-flumazenil ([(18)F]-FMZ) PET could be used to non-invasively characterise GABA(A)/central benzodiazepine receptor (GABA(A)/cBZR) density and affinity in vivo in the post-kainic acid status epilepticus (SE) model of TLE. METHODS: Dynamic [(18)F]-FMZ -PET scans using a multi-injection protocol were acquired in four male wistar rats for validation of the partial saturation model (PSM). SE was induced in eight male Wistar rats (10 weeks of age) by i.p. injection of kainic acid (7.5–25 mg/kg), while control rats (n = 7) received saline injections. Five weeks post-SE, an anatomic MRI scan was acquired and the following week an [(18)F]-FMZ PET scan (3.6–4.6 nmol). The PET data was co-registered to the MRI and regions of interest drawn on the MRI for selected structures. A PSM was used to derive receptor density and apparent affinity from the [(18)F]-FMZ PET data. KEY FINDINGS: The PSM was found to adequately model [(18)F]-FMZ binding in vivo. There was a significant decrease in hippocampal receptor density in the SE group (p<0.01), accompanied by an increase in apparent affinity (p<0.05) compared to controls. No change in cortical receptor binding was observed. Hippocampal volume reduction and cell loss was only seen in a subset of animals. Histological assessment of hippocampal cell loss was significantly correlated with hippocampal volume measured by MRI (p<0.05), but did not correlate with [(18)F]-FMZ binding. SIGNIFICANCE: Alterations to hippocampal GABA(A)/cBZR density and affinity in the post-kainic acid SE model of TLE are detectable in vivo with [(18)F]-FMZ PET and a PSM. These changes are independent from hippocampal cell and volume loss. [(18)F]-FMZ PET is useful for investigating the role that changes GABA(A)/cBZR density and binding affinity play in the pathogenesis of TLE
Dendritic cells loaded with killed breast cancer cells induce differentiation of tumor-specific cytotoxic T lymphocytes
BACKGROUND: Early clinical trials, mostly in the setting of melanoma, have shown that dendritic cells (DCs) expressing tumor antigens induce some immune responses and some clinical responses. A major difficulty is the extension to other tumors, such as breast carcinoma, for which few defined tumor-associated antigens are available. We have demonstrated, using both prostate carcinoma and melanoma as model systems, that DCs loaded with killed allogeneic tumor cell lines can induce CD8(+ )T cells to differentiate into cytotoxic T lymphocytes (CTLs) specific for shared tumor antigens. METHODS: The present study was designed to determine whether DCs would capture killed breast cancer cells and present their antigens to autologous CD4(+ )and CD8(+ )T cells. RESULTS: We show that killed breast cancer cells are captured by immature DCs that, after induced maturation, can efficiently present MHC class I and class II peptides to CD8(+ )and CD4(+ )T lymphocytes. The elicited CTLs are able to kill the target cells without a need for pretreatment with interferon gamma. CTLs can be obtained by culturing the DCs loaded with killed breast cancer cells with unseparated peripheral blood lymphocytes, indicating that the DCs can overcome any potential inhibitory effects of breast cancer cells. CONCLUSION: Loading DCs with killed breast cancer cells may be considered a novel approach to breast cancer immunotherapy and to identification of shared breast cancer antigens
M-theory on `toric' G_2 cones and its type II reduction
We analyze a class of conical G_2 metrics admitting two commuting isometries,
together with a certain one-parameter family of G_2 deformations which
preserves these symmetries. Upon using recent results of Calderbank and
Pedersen, we write down the explicit G_2 metric for the most general member of
this family and extract the IIA reduction of M-theory on such backgrounds, as
well as its type IIB dual. By studying the asymptotics of type II fields around
the relevant loci, we confirm the interpretation of such backgrounds in terms
of localized IIA 6-branes and delocalized IIB 5-branes. In particular, we find
explicit, general expressions for the string coupling and R-R/NS-NS forms in
the vicinity of these objects. Our solutions contain and generalize the field
configurations relevant for certain models considered in recent work of Acharya
and Witten.Comment: 45 pages, references adde
Holonomy of Einstein Lorentzian manifolds
The classification of all possible holonomy algebras of Einstein and vacuum
Einstein Lorentzian manifolds is obtained. It is shown that each such algebra
appears as the holonomy algebra of an Einstein (resp., vacuum Einstein)
Lorentzian manifold, the direct constructions are given. Also the holonomy
algebras of totally Ricci-isotropic Lorentzian manifolds are classified. The
classification of the holonomy algebras of Lorentzian manifolds is reviewed and
a complete description of the spaces of curvature tensors for these holonomies
is given.Comment: Dedicated to to Mark Volfovich Losik on his 75th birthday. This
version is an extended part of the previous version; another part of the
previous version is extended and submitted as arXiv:1001.444
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