Radio-quiet and radio-loud pulsars: similar in Gamma-rays but different in X-rays

We present new Chandra and XMM-Newton observations of a sample of eight radio-quiet Gamma-ray pulsars detected by the Fermi Large Area Telescope. For all eight pulsars we identify the X-ray counterpart, based on the X-ray source localization and the best position obtained from Gamma-ray pulsar timing. For PSR J2030+4415 we found evidence for an about 10 arcsec-long pulsar wind nebula. Our new results consolidate the work from Marelli et al. 2011 and confirm that, on average, the Gamma-ray--to--X-ray flux ratios (Fgamma/Fx) of radio-quiet pulsars are higher than for the radio-loud ones. Furthermore, while the Fgamma/Fx distribution features a single peak for the radio-quiet pulsars, the distribution is more dispersed for the radio-loud ones, possibly showing two peaks. We discuss possible implications of these different distributions based on current models for pulsar X-ray emission.Comment: Accepted for publication in The Astrophysical Journal; 12 pages, 3 figures, 2 table

Extended Lateral Approach for Intra-articular Calcaneal Fractures: An Inverse Relationship between Surgeon Experience and Wound Complications

The current reference standard for the treatment of displaced intra-articular calcaneal fractures is open reduction and internal fixation using an extended lateral approach. In the present retrospective study, we evaluated the results of a consecutive series of patients treated in the same fashion from June 2005 to September 2011 using a subcuticular single-layer closure technique. We also determined the risk factors for the development of wound complications and the rate of wound complications. Also, we assessed which patient, fracture, and surgical characteristics affected these complications. During the 75-month study period, we operated on 53 displaced intra-articular calcaneal fractures in 50 patients using the extended lateral approach. The incision was closed using the subcuticular technique in 49 cases (92.45%). In the subcuticular closure group 2 (4.1%) deep infections and 2 (4.1%) superficial wound complications (1 dehiscence and 1 infection) occurred. Wound edge or flap necrosis was not encountered. The use of bone-void filler and the experience of the surgical team were significantly (p < .001 and p = .026, respectively) associated with the occurrence of wound complications. The subcuticular single-layer suture technique is a suitable closure technique in the treatment of displaced intra-articular calcaneal fractures. It was associated with a low complication rate combined with the extended lateral approach. The effect of bone void fillers on the incidence of complications should receive more attention in future research. The association between wound complications and the experience level of the surgical team supports the need for centralization of this complex injury

reentrance effect in normal-metal/superconducting hybrid loops

We have measured the transport properties of two mesoscopic hybrid loops composed of a normal-metal arm and a superconducting arm. The samples differed in the transmittance of the normal/superconducting interfaces. While the low transmittance sample showed monotonic behavior in the low temperature resistance, magnetoresistance and differential resistance, the high transmittance sample showed reentrant behavior in all three measurements. This reentrant behavior is due to coherent Andreev reflection at the normal/superconducting interfaces. We compare the reentrance effect for the three different measurements and discuss the results based on the theory of quasiclassical Green's functions

Biologically active Phytophthora mating hormone prepared by catalytic asymmetric total synthesis

A Phytophthora mating hormone with an array of 1,5-stereogenic centers has been synthesized by using our recently developed methodology of catalytic enantioselective conjugate addition of Grignard reagents. We applied this methodology in a diastereo- and enantioselective iterative route and obtained two of the 16 possible stereoisomers of Phytophthora hormone α1. These synthetic stereoisomers induced the formation of sexual spores (oospores) in A2 mating type strains of three heterothallic Phytophthora species, P. infestans, P. capsici, and P. nicotianae but not in A1 mating type strains. The response was concentration-dependent, and the oospores were viable. These results demonstrate that the biological activity of the synthetic hormone resembles that of the natural hormone α1. Mating hormones are essential components in the sexual life cycle of a variety of organisms. For plant pathogens like Phytophthora, sexual reproduction is important as a source of genetic variation. Moreover, the thick-walled oospores are the most durable propagules that can survive harsh environmental conditions. Sexual reproduction can thus greatly affect disease epidemics. The availability of synthetic compounds mimicking the activity of Phytophthora mating hormone will be instrumental for further unravelling sexual reproduction in this important group of plant pathogens.

Lattice-dynamics of a Disordered solid-solid Interface

Generic properties of elastic phonon transport at a disordered interface are studied. The results show that phonon transmittance is a strong function of frequency and the disorder correlation length. At frequencies lower than the van Hove singularity the transmittance at a given frequency increases as the correlation length decreases. At low frequencies, this is reflected by different power-laws for phonon conductance across correlated and uncorrelated disordered interfaces which are in approximate agreement with perturbation theory of an elastic continuum. These results can be understood in terms of simple mosaic and two-colour models of the interface.Comment: 17 pages, 5 figures, submitted to PR

Density of States and Energy Gap in Andreev Billiards

We present numerical results for the local density of states in semiclassical Andreev billiards. We show that the energy gap near the Fermi energy develops in a chaotic billiard. Using the same method no gap is found in similar square and circular billiards.Comment: 9 pages, 6 Postscript figure

Functional Outcome and Patient Satisfaction after Displaced Intra-articular Calcaneal Fractures: A Comparison Among Open, Percutaneous, and Nonoperative Treatment

The aim of the present study was to compare the outcomes of patients with a displaced calcaneal fracture treated by open reduction and internal fixation (ORIF), percutaneous treatment, or nonoperative methods. A retrospective cohort study was conducted at a level I trauma center of patients with a displaced intra-articular calcaneal fracture treated from January 1, 2002 to December 31, 2011. The patient-reported outcome measures included the Foot Function Index, American Orthopaedic Foot and Ankle Society hindfoot scale, Short Form-36, the EQ-5D from the EuroQol Group, and a 10-point visual analog scale. Clinical data were collected from 169 patients, and questionnaires were obtained from 78 patients (18 nonoperatively, 27 ORIF, and 33 percutaneously). The late intervention rate was significantly greater in the percutaneous group (n = 18; 30%) than in the ORIF group (n = 6; 12%) or the nonoperative group (n = 8; 13%; p = .030). Significantly more disability was reported in the nonoperative group (median Foot Function Index score, 40 points) than in the ORIF group (median, 16 points; p = .010) or in the percutaneous group (median, 21 points; p = .034). In conclusion, the operatively treated patients (ORIF and percutaneous treatment) reported better functional outcome scores (Foot Function Index and American Orthopaedic Foot and Ankle Society hindfoot scale) than did the nonoperatively treated patients

Conductance fluctuations in mesoscopic normal-metal/superconductor samples

We study the magnetoconductance fluctuations of mesoscopic normal-metal/superconductor (NS) samples consisting of a gold-wire in contact with a niobium film. The magnetic field strength is varied over a wide range, including values that are larger than the upper critical field B_c2 of niobium. In agreement with recent theoretical predictions we find that in the NS sample the rms of the conductance fluctuations (CF) is by a factor of 2.8 +/- 0.4 larger than in the high field regime where the entire system is driven normal conducting. Further characteristics of the CF are discussed.Comment: 4 pages, REVTEX, 3 eps-figures included. To be published in Phys. Rev. Lett.. Changes: one misplaced figure correcte