941 research outputs found
Hyperfine Splitting and the Zeeman Effect in Holographic Heavy-Light Mesons
We inspect the mass spectrum of heavy-light mesons in deformed N=2 super
Yang-Mills theory using the AdS/CFT correspondence. We demonstrate how some of
the degeneracies of the supersymmetric meson spectrum can be removed upon
breaking the supersymmetry, thus leading to the emergence of hyperfine
structure. The explicit SUSY breaking scenarios we consider involve on one hand
tilting one of the two fundamental D7 branes inside the internal R^6 space, and
on the other hand applying an external magnetic field on the (untilted) branes.
The latter scenario leads to the well-known Zeeman effect, which we inspect for
both weak and strong magnetic fields.Comment: 5 pages, 1 figur
On moduli of rings and quadrilaterals: algorithms and experiments
Moduli of rings and quadrilaterals are frequently applied in geometric
function theory, see e.g. the Handbook by K\"uhnau. Yet their exact values are
known only in a few special cases. Previously, the class of planar domains with
polygonal boundary has been studied by many authors from the point of view of
numerical computation. We present here a new -FEM algorithm for the
computation of moduli of rings and quadrilaterals and compare its accuracy and
performance with previously known methods such as the Schwarz-Christoffel
Toolbox of Driscoll and Trefethen. We also demonstrate that the -FEM
algorithm applies to the case of non-polygonal boundary and report results with
concrete error bounds
Flexible Automation and Less Developed Countries: Is CIM Only a Threat to the LDCs?
In this paper, the preconditions and effects of introducing flexible production technologies in LDCs are taken into consideration. The problems of Industrial development in LDCs, especially in NICs, is approached by studying the results from previous research work and by evaluating competing theories of technological development in LDCs.
Two contradicting hypotheses are presented. but neither of them is accepted as such. Both of them are criticized for being too simplifying and too general. The most common theoretical explanation for international industrial development, the theory of comparative advantages, is also taken under critical inspection in Chapter 3. As an overall explanation for LDC development or policy guideline it is rejected, and rather accepted as a normative tool for planning sequential development paths for industries in LDCs.
In chapter 2, a brief historical survey on the development of some industrial branches in various LDCs is presented. The effects of multinational corporations, the development of R&D activities and supply of skilled manpower are taken up as special themes. The features of LDCs are compared to each other and occasionally to some older industrial countries as well.
The picture is enriched with an excursion to recent developments in manufacturing technologies in Chapter 4. The problems of producing and applying flexible automation technologies in LDCs are summarized and formulated into a research approach in Chapter 5. The adopted approach is of a more concrete, more historically and institutionally oriented nature than the most commonly used research methods.
In Chapter 6, some countries are considered as possible targets for a more concrete study on flexible automation and LDCs. In the final chapter, the research approach is developed further and summarized into a sketch for an empiric study starting as a comparative survey between three pairs of countries
Perturbative QCD at non-zero chemical potential: Comparison with the large-Nf limit and apparent convergence
The perturbative three-loop result for the thermodynamic potential of QCD at
finite temperature and chemical potential as obtained in the framework of
dimensional reduction is compared with the exact result in the limit of large
flavor number. The apparent convergence of the former as well as possibilities
for optimization are investigated. Corresponding optimized results for full QCD
are given for the case of two massless quark flavors.Comment: REVTEX4, 4 pages, 3 color figures. v2: fig. 3 now includes also
lattice data for two-flavor QCD at nonzero chemical potentia
Neural Correlates of Letter-String Length and Lexicality during Reading in a Regular Orthography
Behavioral studies have shown that short letter strings are read faster than long letter-strings and words are read faster than nonwords. Here, we describe the dynamics of letter-string length and lexicality effects at the cortical level, using magnetoencephalography, during a reading task in Finnish with long (eight-letter) and short (four-letter) word/nonword stimuli. Length effects were observed in two spatially and temporally distinct cortical activations: (1) in the occipital cortex at about 100 msec by the strength of activation, regardless of the lexical status of the stimuli, and (2) in the left superior temporal cortex between 200 and 600 msec by the duration of activation, with words showing a smaller effect than nonwords. A significant lexicality effect was also evident in this later activation, with stronger activation and longer duration for nonwords than words. There seem to be no distinct cortical areas for reading words and nonwords. The early length effect is likely to be due to the low-level visual analysis common to all stimulus letter-strings. The later lexicality and length effects apparently reflect converging lexico-semantic and phonological influences, and are discussed in terms of dual-route and single-route connectionist models of reading.Peer reviewe
Polymerase Chain Reaction Assay With Urine Specimens in the Diagnosis of Acute Chlamydia trachomatis Infection in Women
Objective: The purpose of this study was to evaluate the benefits achievable by Amplicor polymerase
chain reaction (PCR) (F. Hoffmann-LaRoche Ltd., Basel, Switzerland) with urine specimens
in addition to PACE 2 (Gen-Probe, Inc., San Diego, California) assay with cervical swab specimens
in the diagnosis of Chlamydia trachomatis in women
Two-color QCD via dimensional reduction
We study the thermodynamics of two-color QCD at high temperature and/or
density using a dimensionally reduced superrenormalizable effective theory,
formulated in terms of a coarse grained Wilson line. In the absence of quarks,
the theory is required to respect the Z(2) center symmetry, while the effects
of quarks of arbitrary masses and chemical potentials are introduced via soft
Z(2) breaking operators. Perturbative matching of the effective theory
parameters to the full theory is carried out explicitly, and it is argued how
the new theory can be used to explore the phase diagram of two-color QCD.Comment: 17 pages, 1 eps figure, jheppub style; v2: minor update, references
added, published versio
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