Kertesz on Fat Graphs?

The identification of phase transition points, beta_c, with the percolation thresholds of suitably defined clusters of spins has proved immensely fruitful in many areas of statistical mechanics. Some time ago Kertesz suggested that such percolation thresholds for models defined in field might also have measurable physical consequences for regions of the phase diagram below beta_c, giving rise to a ``Kertesz line'' running between beta_c and the bond percolation threshold, beta_p, in the M, beta plane. Although no thermodynamic singularities were associated with this line it could still be divined by looking for a change in the behaviour of high-field series for quantities such as the free energy or magnetisation. Adler and Stauffer did precisely this with some pre-existing series for the regular square lattice and simple cubic lattice Ising models and did, indeed, find evidence for such a change in high-field series around beta_p. Since there is a general dearth of high-field series there has been no other work along these lines. In this paper we use the solution of the Ising model in field on planar random graphs by Boulatov and Kazakov to carry out a similar exercise for the Ising model on random graphs (i.e. coupled to 2D quantum gravity). We generate a high-field series for the Ising model on $\Phi^4$ random graphs and examine its behaviour for evidence of a Kertesz line

Mycobacterial panniculitis caused by Mycobacterium thermoresistibile in a cat.

Case summaryA domestic shorthair cat was evaluated for chronic, bilateral, ulcerative dermatitis affecting the inguinal region and lateral aspects of both pelvic limbs. Histopathologic examination of skin biopsies collected throughout the course of disease revealed chronic pyogranulomatous ulcerative dermatitis. Aerobic bacterial skin cultures yielded growth of a methicillin-resistant Staphylococcus aureus and Corynebacterium amycolatum. Upon referral the clinical findings were suggestive of a non-tuberculous Mycobacterium species infection. Previously obtained skin cultures failed to yield growth of mycobacterial organisms. A deep skin biopsy was collected and submitted for mycobacterial culture. At 5 weeks of incubation Mycobacterium thermoresistibile was isolated. In previous reports, M thermoresistibile has been isolated after 2-4 days of incubation, suggesting that this strain may have been a slower growing variant, or other factors (such as prior antimicrobial therapy) inhibited rapid growth of this isolate. The cat was hospitalized for intravenous antibiotic therapy, surgical debridement of wounds, vacuum-assisted wound closure therapy and reconstruction procedures. The wounds were ultimately primarily closed and the cat was discharged to the owner after 50 days of hospitalization. Seven months after hospitalization, the ulcerative skin lesions had healed.Relevance and novel informationTo our knowledge, only two cases of M thermoresistibile panniculitis have been reported in cats. In the only detailed report of feline M thermoresistibile panniculitis, treatment was not attempted. The second case only reported detection of M thermoresistibile by PCR without a clinical description of the case. In our case report, severe chronic skin infection with M thermoresistibile was addressed using prolonged specific antibiotic therapy, surgical debridement and reconstructions, and treatment of secondary bacterial infections

The Carboxyl-Terminal Segment of Apolipoprotein A-V Undergoes a Lipid-Induced Conformational Change

Apolipoprotein (apo) A-V is a 343-residue, multidomain protein that plays an important role in regulation of plasma triglyceride homeostasis. Primary sequence analysis revealed a unique tetraproline sequence (Pro293-Pro296) near the carboxyl terminus of the protein. A peptide corresponding to the 48-residue segment beyond the tetraproline motif was generated from a recombinant apoA-V precursor wherein Pro295 was replaced by Met. Cyanogen bromide cleavage of the precursor protein, followed by negative affinity chromatography, yielded a purified peptide. Nondenaturing polyacrylamide gel electrophoresis verified that apoA-V(296-343) solubilizes phospholipid vesicles, forming a relatively heterogeneous population of reconstituted high-density lipoprotein with Stokes’ diameters\u3e17 nm. At the same time, apoA-V(296-343) failed to bind a spherical lipoprotein substrate in vitro. Far-UV circular dichroism spectroscopy revealed the peptide is unstructured in buffer yet adopts significant R-helical secondary structure in the presence of the lipid mimetic solvent trifluoroethanol (TFE; 50% v/v). Heteronuclear multidemensional NMR spectroscopy experiments were conducted with uniformly 15N- and 15N/13C-labeled peptide in 50% TFE. Peptide backbone assignment and secondary structure prediction using TALOSþ reveal the peptide adopts R-helix secondary structure from residues 309 to 334. In TFE, apoA-V(296-343) adopts an extended amphipathic R-helix, consistent with a role in lipoprotein binding as a component of full-length apoA-V

Development of computer software to analyze entire LANDSAT scenes and to summarize classification results of variable-size polygons

The Forest Pest Management Division (FPMD) of the Pennsylvania Bureau of Forestry has the responsibility for conducting annual surveys of the State's forest lands to accurately detect, map, and appraise forest insect infestations. A standardized, timely, and cost-effective method of accurately surveying forests and their condition should enhance the probability of suppressing infestations. The repetitive and synoptic coverage provided by LANDSAT (formerly ERTS) makes such satellite-derived data potentially attractive as a survey medium for monitoring forest insect damage over large areas. Forest Pest Management Division personnel have expressed keen interest in LANDSAT data and have informally cooperated with NASA/Goddard Space Flight Center (GSFC) since 1976 in the development of techniques to facilitate their use. The results of this work indicate that it may be feasible to use LANDSAT digital data to conduct annual surveys of insect defoliation of hardwood forests

The Steward Observatory asteroid relational database

The Steward Observatory Asteroid Relational Database (SOARD) was created as a flexible tool for undertaking studies of asteroid populations and sub-populations, to probe the biases intrinsic to asteroid databases, to ascertain the completeness of data pertaining to specific problems, to aid in the development of observational programs, and to develop pedagogical materials. To date SOARD has compiled an extensive list of data available on asteroids and made it accessible through a single menu-driven database program. Users may obtain tailored lists of asteroid properties for any subset of asteroids or output files which are suitable for plotting spectral data on individual asteroids. A browse capability allows the user to explore the contents of any data file. SOARD offers, also, an asteroid bibliography containing about 13,000 references. The program has online help as well as user and programmer documentation manuals. SOARD continues to provide data to fulfill requests by members of the astronomical community and will continue to grow as data is added to the database and new features are added to the program

Neutron spectroscopic factors of Ni isotopes from transfer reactions

177 neutron spectroscopic factors for nickel isotopes have been extracted by performing a systematic analysis of the angular distributions measured from (d,p) transfer reactions. A subset of the extracted spectroscopic factors are compared to predictions of large-basis shell models in the full pf model space using the GXPF1A effective interaction, and the (f5/2, p3/2, p1/2, g9/2) model space using the JJ4PNA interaction. For ground states, the predicted spectroscopic factors using the GXPF1A effective interaction in the full pf model space agree very well with the experimental values, while predictions based on several other effective interactions and model spaces are about 30% higher than the experimental values. For low-energy excited states (<3.5 MeV), the agreement between the extracted spectroscopic factors and shell model calculations is not better than a factor of two.Comment: 18 pages, 4 figures, 2 tables. accepted for publication in PR

Anisotropic expansion of a thermal dipolar Bose gas

We report on the anisotropic expansion of ultracold bosonic dysprosium gases at temperatures above quantum degeneracy and develop a quantitative theory to describe this behavior. The theory expresses the post-expansion aspect ratio in terms of temperature and microscopic collisional properties by incorporating Hartree-Fock mean-field interactions, hydrodynamic effects, and Bose-enhancement factors. Our results extend the utility of expansion imaging by providing accurate thermometry for dipolar thermal Bose gases, reducing error in expansion thermometry from tens of percent to only a few percent. Furthermore, we present a simple method to determine scattering lengths in dipolar gases, including near a Feshbach resonance, through observation of thermal gas expansion.Comment: main text and supplement, 11 pages total, 4 figure

The effects of space radiation on a chemically modified graphite-epoxy composite material

The effects of the space environment on the engineering properties and chemistry of a chemically modified T300/934 graphite-epoxy composite system are characterized. The material was subjected to 1.0 x 10 to the 10th power rads of 1.0 MeV electron irradiation under vacuum to simulate 30 years in geosynchronous earth orbit. Monotonic tension tests were performed at room temperature (75 F/24 C) and elevated temperature (250 F/121 C) on 4-ply unidirectional laminates. From these tests, inplane engineering and strength properties (E sub 1, E sub 2, Nu sub 12, G sub 12, X sub T, Y sub T) were determined. Cyclic tests were also performed to characterize energy dissipation changes due to irradiation and elevated temperature. Large diameter graphite fibers were tested to determine the effects of radiation on their stiffness and strength. No significant changes were observed. Dynamic-mechanical analysis demonstrated that the glass transition temperature was reduced by 50 F(28 C) after irradiation. Thermomechanical analysis showed the occurrence of volatile products generated upon heating of the irradiated material. The chemical modification of the epoxy did not aid in producing a material which was more radiation resistant than the standard T300/934 graphite-epoxy system. Irradiation was found to cause crosslinking and chain scission in the polymer. The latter produced low molecular weight products which plasticize the material at elevated temperatures and cause apparent material stiffening at low stresses at room temperature