Convergence radius of perturbative Lindblad driven non-equilibrium steady states

We address the problem of analyzing the radius of convergence of perturbative expansion of non-equilibrium steady states of Lindblad driven spin chains. A simple formal approach is developed for systematically computing the perturbative expansion of small driven systems. We consider the paradigmatic model of an open $XXZ$ spin 1/2 chain with boundary supported ultralocal Lindblad dissipators and treat two different perturbative cases: (i) expansion in system-bath coupling parameter and (ii) expansion in driving (bias) parameter. In the first case (i) we find that the radius of convergence quickly shrinks with increasing the system size, while in the second case (ii) we find that the convergence radius is always larger than $1$, and in particular it approaches $1$ from above as we change the anisotropy from easy plane ($XY$) to easy axis (Ising) regime

Infrared observations of the dust coma

The main infrared observational results were briefly reviewed at the start of this session. The new results are summarized. All of these results have yet to be synthesized into a self-consistent picture of the dust grain composition, dust production history, outburst mechanisms, and composition of the nucleus. The workshop discussion was helpful in pointing out problems faced by theorists, such as data quality, the lack of the proper theory for computing the scattering and emission of irregular particles, and in some cases the lack of optical constants of realistic materials. It is expected that the gross spectral and dynamical properties of Halley's Comet can be understood in time, even if the details of the observations and the theoretical calculations continue to vex us in the future

The dust coma of Comet Austin (1989c1)

Thermal-infrared (10 and 20 micron) images of Comet Austin were obtained on UT 30.6 Apr., 1.8, 2.8, and 3.6 May 1990. The NASA-Marshall Space Flight Center 20 pixel bolometer array at the NASA 3 meter Infrared Telescope Facility in Hawaii was used. The 10.8 micron (FWHM = 5.3 microns) maps were obtained with maximum dimensions of 113 arcsec (57,500 km) in RA and 45 arcsec (23,000 km) in declination, with a pixel size of 4.2 x 4.2 arcsec. A smaller, 45 x 18 arcsec, map was obtained in the 19.2 micron (FWHM = 5.2 microns) bandpass. At the time of these observations Comet Austin's heliocentric and geocentric distances were 0.7 and 0.5 AU respectively. The peak flux density (within the brightest pixel) was 23 + or - 2 Janskys for the first three dates and only marginally lower the last day; i.e., within the observational uncertainties no evidence was found for day-to-day variability like that observed in Comet Halley. A dynamical analysis of the morphology of the extended dust emission is used to constrain the size distribution and production rate of the dust particles. The results of this analysis are compared with similar studies carried out on comets P/Giacobini-Zinner, P/Brorsen-Metcalf, P/Halley, P/Tempel 2, and Wilson (1987)

Airborne 20-65 micron spectrophotometry of Comet Halley

Observations of Comet Halley with a grating spectrometer on board the Kuiper Airborne Observatory on four nights in Dec. 1985 to Apr. 1986 are reported. Low resolution 20 to 65 micrometer spectra of the nucleus with a 40 arcsec FWHM beam was obtained on 17 Dec. 1985, and on 15 and 17 Apr. 1986. On 20 Dec. 1985, only a 20 to 35 micrometer spectrum was obtained. Most of the data have been discussed in a paper where the continuum was dealt with. In that paper, models were fit to the continuum that showed that more micron sized particles of grain similar to amorphous carbon were needed to fit the spectrum than were allowed by the Vega SP-2 mass distribution, or that a fraction of the grains had to be made out of a material whose absorption efficiency fell steeper than lambda sup -1 for lambda greater than 20 micrometers. Spectra was also presented taken at several points on the coma on 15 Apr. which showed that the overall shape to the spectrum is the same in the coma. Tabulated values of the data and calibration curves are available. The spectral features are discussed

Invasive Wild pigs as primary nest predators for Wild turkeys

Depredation of wild turkey (Meleagris gallopavo) nests is a leading cause of reduced recruitment for the recovering and iconic game species. invasive wild pigs (Sus scrofa) are known to depredate nests, and have been expanding throughout the distributed range of wild turkeys in north America. We sought to gain better insight on the magnitude of wild pigs depredating wild turkey nests. We constructed simulated wild turkey nests throughout the home ranges of 20 GPS-collared wild pigs to evaluate nest depredation relative to three periods within the nesting season (i.e., early, peak, and late) and two nest densities (moderate = 12.5-25 nests/km2, high = 25-50 nests/km2) in south-central Texas, USA during March–June 2016. Overall, the estimated probability of nest depredation by wild pigs was 0.3, equivalent to native species of nest predators in the study area (e.g., gray fox [Urocyon cinereoargenteus], raccoon [Procyon lotor], and coyote [Canis latrans]). female wild pigs exhibited a constant rate of depredation regardless of nesting period or density of nests. However, male wild pigs increased their rate of depredation in areas with higher nest densities. Management efforts should remove wild pigs to reduce nest failure in wild turkey populations especially where recruitment is low

SFMetrics: An analysis tool for scanning force microscopy images of biomolecules

Scanning force microscopy (SFM) allows direct, rapid and high-resolution visualization of single molecular complexes; irregular shapes and differences in sizes are immediately revealed by the scanning tip in three-dimensional images. However, high-throughput analysis of SFM data is limited by the lack of versatile software tools accessible to SFM users. Most existing SFM software tools are aimed at broad general use: from material-surface analysis to visualization of biomolecules. Results: We present SFMetrics as a metrology toolbox for SFM, specifically aimed at biomolecules like DNA and proteins, which features (a) semi-automatic high-throughput analysis of individual molecules; (b) ease of use working within MATLAB environment or as a stand-alone application; (c) compatibility with MultiMode (Bruker), NanoWizard (JPK instruments), Asylum (Asylum research), ASCII, and TIFF files, that can be adjusted with minor modifications to other formats. Conclusion: Assembled in a single user interface, SFMetrics serves as a semi-automatic analysis tool capable of measuring several geometrical properties (length, volume and angles) from DNA and protein complexes, but is also applicable to other samples with irregular shapes. &Copy; Malm et al.; licensee BioMed Central