2,187 research outputs found
Pulmonary Hydatid Cyst with Complicating Aspergillus Infection Presenting as a Refractory Lung Abscess
Background Hydatid disease is rare in the United States. Rarely the hydatid cyst can become infected with mycotic organisms, such as Aspergillus . We describe a young male who presents with clinical features of suppurative lung abscess whose workup diagnosed hydatid cyst complicated by Aspergillus co-infection. Case presentation A 27-year-old Peruvian male was hospitalized because of fever, chills, and productive cough of three months’ duration. Clinical features were consistent with a suppurative lung abscess. Significant findings included leukocytosis with eosinophilia and a chest x-ray showing a large lingular lobe thick walled cavity with a wavy irregular fluid level. The patient ultimately underwent surgical resection of the lingular lobe. Examination of the surgical specimen revealed the cavity to be a hydatid cyst. Histologic examination of the cyst wall showed intense inflammation and several septate hyphae of Aspergillus species. The patient recovered fully and has remained in good health. Conclusion A thick-walled cavity and a wavy meniscus constitute unusual features for an ordinary pyogenic lung abscess and suggests other possibilities. Endogenous cases of hydatid disease are uncommon in the United States, with the majority of cases occurring in immigrants. There are few published case reports describing incidental findings of Aspergillus in a hydatid cyst. The rare occurrence of such a condition can lead to a delay in diagnosis and treatment
Stoke-on-Trent: a geological background for planning and development
This study, carried out between 1988 and 1990, was commissioned by the Department of the Environment (DOE)
and funded jointly by the Department and the British
Geological Survey (BGS). Its main aim was to make a synthesis of geological data relevant to planning of land-use and development in the Stoke-on-Trent area. This report is specifically written for planners and there has been an
attempt to avoid complex geological terms. Besides text
illustrations the report includes ten thematic maps at a common scale of 1 :25 000. An additional volume concentrates
on engineering geology for site investigation companies.
Seven further short reports feature geological details of separate 1: 10 000 sheets, couched in more technical language
Ultraviolet Fixed Points in Gauge and SUSY Field Theories in Extra Dimensions
We consider gauge field theories in following the Wilson RG approach
and show that they possess the ultraviolet fixed points where the gauge
coupling is dimensionless in any space-time dimension. At the fixed point the
anomalous dimensions of the field and vertex operators are known exactly. These
fixed points are nonperturbative and correspond to conformal invariant
theories. The same phenomenon also happens in supersymmetric theories with the
Yukawa type interactions.Comment: LaTeX, 10pp. v2: Comments and references adde
Scaling algebras and pointlike fields: A nonperturbative approach to renormalization
We present a method of short-distance analysis in quantum field theory that
does not require choosing a renormalization prescription a priori. We set out
from a local net of algebras with associated pointlike quantum fields. The net
has a naturally defined scaling limit in the sense of Buchholz and Verch; we
investigate the effect of this limit on the pointlike fields. Both for the
fields and their operator product expansions, a well-defined limit procedure
can be established. This can always be interpreted in the usual sense of
multiplicative renormalization, where the renormalization factors are
determined by our analysis. We also consider the limits of symmetry actions. In
particular, for suitable limit states, the group of scaling transformations
induces a dilation symmetry in the limit theory.Comment: minor changes and clarifications; as to appear in Commun. Math.
Phys.; 37 page
Quenched Lattice QCD with Domain Wall Fermions and the Chiral Limit
Quenched QCD simulations on three volumes, , and
and three couplings, , 5.85 and 6.0 using domain
wall fermions provide a consistent picture of quenched QCD. We demonstrate that
the small induced effects of chiral symmetry breaking inherent in this
formulation can be described by a residual mass (\mres) whose size decreases
as the separation between the domain walls () is increased. However, at
stronger couplings much larger values of are required to achieve a given
physical value of \mres. For and , we find
\mres/m_s=0.033(3), while for , and ,
\mres/m_s=0.074(5), where is the strange quark mass. These values are
significantly smaller than those obtained from a more naive determination in
our earlier studies. Important effects of topological near zero modes which
should afflict an accurate quenched calculation are easily visible in both the
chiral condensate and the pion propagator. These effects can be controlled by
working at an appropriately large volume. A non-linear behavior of in
the limit of small quark mass suggests the presence of additional infrared
subtlety in the quenched approximation. Good scaling is seen both in masses and
in over our entire range, with inverse lattice spacing varying between
1 and 2 GeV.Comment: 91 pages, 34 figure
Review of Dental Impression Materials
Major advances in impression materials and their application have occurred during the last decade, with greater emphasis being placed on rubber impression materials than on dental compound, zinc oxide-eugenol, and agar and alginate. Of particular interest has been the effect of disinfection solutions on the qualities of impressions and the biocompatibility of impression materials. The principal advance in hydrocolloids has been the introduction of the agar/alginate impression technique, which has simplified the procedure and improved the quality of gypsum dies compared with those prepared in alginate impressions. The tear strength of some alginates has been improved, and some have been formulated so that the powder is dustless, thus reducing the health hazard as a result of patient inhalation of dust during the dispensing process. Polyether and silicone impression materials have been modified so that the working time, viscosity, and flexibility of the polyethers have been improved and, with the introduction of addition silicones, their accuracy has become exceptional. Although the early addition silicones liberated hydrogen after setting, thus delaying the pouring of models and dies, most addition silicones have been improved so that no hydrogen is released and dies can be poured immediately. The introduction of automatic mixing systems for addition silicones has simplified their manipulation, has reduced the number of voids in impressions, and has reduced the amount of material wasted. The incorporation of surfactants into addition silicones has made them hydrophilic, with wetting properties similar to those of polyethers, and has made pouring bubble-free gypsum dies easier. This review is confined to published and unpublished information of the past decade. It will also suggest trends that should be anticipated in the near future based on this information. The review will not present information developed before 1975, which is available in several textbooks on dental materials by Craig (1985a), Phillips (1982), and Williams and Cunningham (1979).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66604/2/10.1177_08959374880020012001.pd
Detection of magnetized quark-nuggets, a candidate for dark matter
AbstractQuark nuggets are theoretical objects composed of approximately equal numbers of up, down, and strange quarks and are also called strangelets and nuclearites. They have been proposed as a candidate for dark matter, which constitutes ~85% of the universe’s mass and which has been a mystery for decades. Previous efforts to detect quark nuggets assumed that the nuclear-density core interacts directly with the surrounding matter so the stopping power is minimal. Tatsumi found that quark nuggets could well exist as a ferromagnetic liquid with a ~1012-T magnetic field. We find that the magnetic field produces a magnetopause with surrounding plasma, as the earth’s magnetic field produces a magnetopause with the solar wind, and substantially increases their energy deposition rate in matter. We use the magnetopause model to compute the energy deposition as a function of quark-nugget mass and to analyze testing the quark-nugget hypothesis for dark matter by observations in air, water, and land. We conclude the water option is most promising.</jats:p
Continuum theory of vacancy-mediated diffusion
We present and solve a continuum theory of vacancy-mediated diffusion (as
evidenced, for example, in the vacancy driven motion of tracers in crystals).
Results are obtained for all spatial dimensions, and reveal the strongly
non-gaussian nature of the tracer fluctuations. In integer dimensions, our
results are in complete agreement with those from previous exact lattice
calculations. We also extend our model to describe the vacancy-driven
fluctuations of a slaved flux line.Comment: 25 Latex pages, subm. to Physical Review
Effective action and density functional theory
The effective action for the charge density and the photon field is proposed
as a generalization of the density functional. A simple definition is given for
the density functional, as the functional Legendre transform of the generator
functional of connected Green functions for the density and the photon field,
offering systematic approximation schemes. The leading order of the
perturbation expansion reproduces the Hartree-Fock equation. A renormalization
group motivated method is introduced to turn on the Coulomb interaction
gradually and to find corrections to the Hartree-Fock and the Kohn-Sham
schemes.Comment: New references and a numerical algorithm added, to appear in Phys.
Rev. B. 30 pages, no figure
The global atmospheric electrical circuit and climate
Evidence is emerging for physical links among clouds, global temperatures, the global atmospheric electrical circuit and cosmic ray ionisation. The global circuit extends throughout the atmosphere from the planetary surface to the lower layers of the ionosphere. Cosmic rays are the principal source of atmospheric ions away from the continental boundary layer: the ions formed permit a vertical conduction current to flow in the fair weather part of the global circuit. Through the (inverse) solar modulation of cosmic rays, the resulting columnar ionisation changes may allow the global circuit to convey a solar influence to meteorological phenomena of the lower atmosphere. Electrical effects on non-thunderstorm clouds have been proposed to occur via the ion-assisted formation of ultra-fine aerosol, which can grow to sizes able to act as cloud condensation nuclei, or through the increased ice nucleation capability of charged aerosols. Even small atmospheric electrical modulations on the aerosol size distribution can affect cloud properties and modify the radiative balance of the atmosphere, through changes communicated globally by the atmospheric electrical circuit. Despite a long history of work in related areas of geophysics, the direct and inverse relationships between the global circuit and global climate remain largely quantitatively unexplored. From reviewing atmospheric electrical measurements made over two centuries and possible paleoclimate proxies, global atmospheric electrical circuit variability should be expected on many timescale
- …