The Role of Bordetella Infections in Patients with Acute Exacerbation of Chronic Bronchitis

Abstract : Background: : Acute exacerbations of chronic bronchitis (AECB) are associated with a variety of viral and bacterial infectious agents, some of which are potentially preventable by immunization. Bordetella pertussis, which causes whooping cough, has not been studied in this context. We aimed to assess the role of Bordetella infections in patients with AECB. Patients and Methods: : Patients with AECB, who presented to participating private practices in Basel, Switzerland, between October 2000 and June 2002, were evaluated by a standardized questionnaire, nasopharyngeal swabs for culture (Bordetella spp.), and PCR (Bordetella spp. and selected other respiratory pathogens) and paired blood samples for serologic diagnosis of Bordetella infection. Results: : A total of 26 patients (34-86 years of age) were recruited. All culture and PCR samples were negative. Serology revealed Bordetella infection in eight (31%) patients. Duration of cough was shorter in patients with Bordetella infection compared to those without Bordetella infection (mean 15 days vs 41 days, p = 0.04). Cough ≥ 21 days duration was present in three (43%) of seven patients with evidence of Bordetella infection compared to 17 (94%) of 18 controls (p = 0.012). Progression to convalescence from initial to follow-up visit after 4-6 weeks was comparable between both groups. Conclusion: : Bordetella infections appear to play a significant role in AECB and preventive measurements such as immunization with acellular pertussis vaccines should be considered. Extended investigations are necessary to confirm our preliminary and provocative finding

Quantum Link Models with Many Rishon Flavors and with Many Colors

Quantum link models are a novel formulation of gauge theories in terms of discrete degrees of freedom. These degrees of freedom are described by quantum operators acting in a finite-dimensional Hilbert space. We show that for certain representations of the operator algebra, the usual Yang-Mills action is recovered in the continuum limit. The quantum operators can be expressed as bilinears of fermionic creation and annihilation operators called rishons. Using the rishon representation the quantum link Hamiltonian can be expressed entirely in terms of color-neutral operators. This allows us to study the large N_c limit of this model. In the 't Hooft limit we find an area law for the Wilson loop and a mass gap. Furthermore, the strong coupling expansion is a topological expansion in which graphs with handles and boundaries are suppressed.Comment: Lattice2001(theorydevelop), poster by O. Baer and talk by B. Schlittgen, 6 page

Dewetting of thin films on heterogeneous substrates: Pinning vs. coarsening

We study a model for a thin liquid film dewetting from a periodic heterogeneous substrate (template). The amplitude and periodicity of a striped template heterogeneity necessary to obtain a stable periodic stripe pattern, i.e. pinning, are computed. This requires a stabilization of the longitudinal and transversal modes driving the typical coarsening dynamics during dewetting of a thin film on a homogeneous substrate. If the heterogeneity has a larger spatial period than the critical dewetting mode, weak heterogeneities are sufficient for pinning. A large region of coexistence between coarsening dynamics and pinning is found.Comment: 4 pages, 4 figure

New Results on e+e- Line Emission in U+Ta Collisions

We present new results obtained from a series of follow-up e+e- coincidence measurements in heavy-ion collisions, utilizing an improved experimental set-up at the double-Orange beta-spectrometer of GSI. The collision system U+Ta was reinvestigated in three independent runs at beam energies in the range (6.0-6.4)xA MeV and different target thicknesses, with the objective to reproduce a narrow sum-energy e+e- line at ~635 keV observed previously in this collision system. At improved statistical accuracy, the line could not be found in these new data. For the ''fission'' scenario, an upper limit (1 sigma) on its production probability per collision of 1.3x10^{-8} can be set which has to be compared to the previously reported value of [4.9 +- 0.8 (stat.) +- 1.0 (syst)]x10^{-7}. In the light of the new results, a reanalysis of the old data shows that the continuous part of the spectrum at the line position is significantly higher than previously assumed, thus reducing the production probability of the line by a factor of two and its statistical significance to < 3.4sigma.Comment: 15 pages, standard LaTeX with 3 included PS figures; Submitted to Physics Letters

Can One See the Number of Colors?

We formulate the standard model with an arbitrary number of colors N_c. The cancellation of Witten's global SU(2)_L anomaly requires N_c to be odd, while the cancellation of triangle anomalies determines the consistent N_c-dependent values of the quark charges. In this theory, the width of the neutral pion decay into two photons is not proportional to (N_c)^2. In fact, in the case of a single generation and hence for two quark flavors (N_f = 2), N_c does not appear explicitly in the low-energy effective theory of the standard model. Hence, contrary to common lore, it is impossible to see the number of colors in low-energy experiments with just pions and photons. For N_f > 2, on the other hand, N_c explicitly enters the chiral Lagrangian as the quantized prefactor of the Wess-Zumino-Witten term, but the contribution of this term to photon-pion vertices is completely canceled by the N_c-dependent part of a Goldstone-Wilczek term. However, the width of the eta decay into pi^+ pi^- gamma survives the cancellation and is indeed proportional to (N_c)^2. By detecting the emerging photon, this process thus allows one to literally see N_c for N_f > 2.Comment: 24 pages, no figures, Late

Strategic responses to global challenges: The case of European banking, 1973–2000

In applying a strategy, structure, ownership and performance (SSOP) framework to three major clearing banks (ABN AMRO, UBS, Barclays), this article debates whether the conclusions generated by Whittington and Mayer about European manufacturing industry can be applied to the financial services sector. While European integration plays a key role in determining strategy, it is clear that global factors were far more important in determining management actions, leading to significant differences in structural adaptation. The article also debates whether this has led to improved performance, given the problems experienced with both geographical dispersion and diversification, bringing into question the quality of decision-making over the long term

K\"ahlerian Twistor Spinors

On a K\"ahler spin manifold K\"ahlerian twistor spinors are a natural analogue of twistor spinors on Riemannian spin manifolds. They are defined as sections in the kernel of a first order differential operator adapted to the K\"ahler structure, called K\"ahlerian twistor (Penrose) operator. We study K\"ahlerian twistor spinors and give a complete description of compact K\"ahler manifolds of constant scalar curvature admitting such spinors. As in the Riemannian case, the existence of K\"ahlerian twistor spinors is related to the lower bound of the spectrum of the Dirac operator.Comment: shorter version; to appear in Math.

D-Theory: Field Quantization by Dimensional Reduction of Discrete Variables

D-theory is an alternative non-perturbative approach to quantum field theory formulated in terms of discrete quantized variables instead of classical fields. Classical scalar fields are replaced by generalized quantum spins and classical gauge fields are replaced by quantum links. The classical fields of a d-dimensional quantum field theory reappear as low-energy effective degrees of freedom of the discrete variables, provided the (d+1)-dimensional D-theory is massless. When the extent of the extra Euclidean dimension becomes small in units of the correlation length, an ordinary d-dimensional quantum field theory emerges by dimensional reduction. The D-theory formulation of scalar field theories with various global symmetries and of gauge theories with various gauge groups is constructed explicitly and the mechanism of dimensional reduction is investigated.Comment: 30 pages, no figure

Pions versus Magnons: From QCD to Antiferromagnets and Quantum Hall Ferromagnets

The low-energy dynamics of pions and magnons -- the Goldstone bosons of the strong interactions and of magnetism -- are analogous in many ways. The electroweak interactions of pions result from gauging an SU(2)_L x U(1)_Y symmetry which then breaks to the U(1)_{em} gauge symmetry of electromagnetism. The electromagnetic interactions of magnons arise from gauging not only U(1)_{em} but also the SU(2)_s spin rotational symmetry, with the electromagnetic fields E and B appearing as non-Abelian vector potentials. Pions couple to electromagnetism through a Goldstone-Wilczek current that represents the baryon number of Skyrmions and gives rise to the decay \pi^0 to \gamma \gamma. Similarly, magnons may couple to an analogue of the Goldstone-Wilczek current for baby-Skyrmions which induces a magnon-two-photon vertex. The corresponding analogue of photon-axion conversion is photon-magnon conversion in an external magnetic field. The baryon number violating decay of Skyrmions can be catalyzed by a magnetic monopole via the Callan-Rubakov effect. Similarly, baby-Skyrmion decay can be catalyzed by a charged wire. For more than two flavors, the Wess-Zumino-Witten term enters the low-energy pion theory with a quantized prefactor N_c -- the number of quark colors. The magnon analogue of this prefactor is the anyon statistics angle \theta which need not be quantized.Comment: 34 pages, no figure

Closed forms and multi-moment maps

We extend the notion of multi-moment map to geometries defined by closed forms of arbitrary degree. We give fundamental existence and uniqueness results and discuss a number of essential examples, including geometries related to special holonomy. For forms of degree four, multi-moment maps are guaranteed to exist and are unique when the symmetry group is (3,4)-trivial, meaning that the group is connected and the third and fourth Lie algebra Betti numbers vanish. We give a structural description of some classes of (3,4)-trivial algebras and provide a number of examples.Comment: 36 page