Orbital Solutions and Absolute Elements of the Eclipsing Binary MY Cygni

Differential UBV photoelectric photometry for the eclipsing binary MY Cyg is presented. The Wilson-Devinney program is used to simultaneously solve the three light curves together with previously published radial velocities. A comparison is made with the previous solution found with the Russell-Merrill method. We examine the long-term apsidal motion of this well-detached, slightly eccentric system. We determine absolute dimensions, discuss metallicity/Am-star issues, and estimate the evolutionary status of the stars

Assessment of Agricultural Information Needs in African, Caribbean and Pacific (ACP) States: West Africa: Country study Liberia

The study aimed to provide insight on status of infrastructure, information services and ICM capacity of institutions involved in agriculture and rural development, Information and capacity building needs in the area of ICM identified for key institutions and potential CTA partners involved in ARD and potential strategic partners for CTA activities and services identified and baseline data on the status of ICM and ICT in ARD compiled for monitoring purposes and improved outreach..

The 8 o'clock Arc: A Serendipitous Discovery of a Strongly Lensed Lyman Break Galaxy in the SDSS DR4 Imaging Data

We report on the serendipitous discovery of the brightest Lyman Break Galaxy (LBG) currently known, a galaxy at z=2.73 that is being strongly lensed by the z=0.38 Luminous Red Galaxy (LRG) SDSS J002240.91+143110.4. The arc of this gravitational lens system, which we have dubbed the "8 o'clock arc" due to its time of discovery, was initially identified in the imaging data of the Sloan Digital Sky Survey Data Release 4 (SDSS DR4); followup observations on the Astrophysical Research Consortium (ARC) 3.5m telescope at Apache Point Observatory confirmed the lensing nature of this system and led to the identification of the arc's spectrum as that of an LBG. The arc has a spectrum and a redshift remarkably similar to those of the previous record-holder for brightest LBG (MS 1512-cB58, a.k.a "cB58"), but, with an estimated total magnitude of (g,r,i) = (20.0,19.2,19.0) and surface brightness of (mu_g,mu_r,mu_i) = (23.3, 22.5, 22.3) mag/arcsec^2, the 8 o'clock arc is thrice as bright. The 8 o'clock arc, which consists of three lensed images of the LBG, is 162deg (9.6arcsec) long and has a length-to-width ratio of 6:1. A fourth image of the LBG -- a counter-image -- can also be identified in the ARC 3.5m g-band images. A simple lens model for the system assuming a singular isothermal ellipsoid potential yields an Einstein radius of 2.91+/-0.14 arcsec, a total mass for the lensing LRG (within the (10.6+/-0.5)/h kpc enclosed by the lensed images) of 1.04x10^12/h Msun, and a magnification factor for the LBG of 12.3(+15/-3.6). The LBG itself is intrinsically quite luminous (approximately 6L*) and shows indications of massive recent star formation, perhaps as high as 160/h Msun/year.Comment: 4 pages 5 figures, submitted to ApJ Letter

Adaptation to ephemeral habitat may overcome natural barriers and severe habitat fragmentation in a fire-dependent species, the Bachman\u27s Sparrow (Peucaea aestivalis)

Bachman\u27s Sparrow (Peucaea aestivalis) is a fire-dependent species that has undergone range-wide population declines in recent decades. We examined genetic diversity in Bachman\u27s Sparrows to determine whether natural barriers have led to distinct population units and to assess the effect of anthropogenic habitat loss and fragmentation. Genetic diversity was examined across the geographic range by genotyping 226 individuals at 18 microsatellite loci and sequencing 48 individuals at mitochondrial and nuclear genes. Multiple analyses consistently demonstrated little genetic structure and high levels of genetic variation, suggesting that populations are panmictic. Based on these genetic data, separate management units/subspecies designations or translocations to promote gene flow among fragmented populations do not appear to be necessary. Panmixia in Bachman\u27s Sparrow may be a consequence of an historical range expansion and retraction. Alternatively, high vagility in Bachman\u27s Sparrow may be an adaptation to the ephemeral, fire-mediated habitat that this species prefers. In recent times, high vagility also appears to have offset inbreeding and loss of genetic diversity in highly fragmented habitat. © 2014 Cerame et al

The Cut & Enhance method : selecting clusters of galaxies from the SDSS commissioning data

We describe an automated method, the Cut & Enhance method (CE) for detecting clusters of galaxies in multi-color optical imaging surveys. This method uses simple color cuts, combined with a density enhancement algorithm, to up-weight pairs of galaxies that are close in both angular separation and color. The method is semi-parametric since it uses minimal assumptions about cluster properties in order to minimize possible biases. No assumptions are made about the shape of clusters, their radial profile or their luminosity function. The method is successful in finding systems ranging from poor to rich clusters of galaxies, of both regular and irregular shape. We determine the selection function of the CE method via extensive Monte Carlo simulations which use both the real, observed background of galaxies and a randomized background of galaxies. We use position shuffled and color shuffled data to perform the false positive test. We have also visually checked all the clusters detected by the CE method. We apply the CE method to the 350 deg^2 of the SDSS (Sloan Digital Sky Survey) commissioning data and construct a SDSS CE galaxy cluster catalog with an estimated redshift and richness for each cluster. The CE method is compared with other cluster selection methods used on SDSS data such as the Matched Filter (Postman et al. 1996, Kim et al. 2001), maxBCG technique (Annis et al. 2001) and Voronoi Tessellation (Kim et al. 2001). The CE method can be adopted for cluster selection in any multi-color imaging surveys.Comment: 62 pages, 32 figures, Accepted for publication in the Astronomical Journal, "the CE galaxy cluster catalog can be downloaded from, http://astrophysics.phys.cmu.edu/~tomo/ce/

Discriminating cool-water from warm-water carbonates and their diagenetic environments using element geochemistry: the Oligocene Tikorangi Formation (Taranaki Basin) and the dolomite effect

Fields portrayed within bivariate element plots have been used to distinguish between carbonates formed in warm- (tropical) water and cool- (temperate) water depositional settings. Here, element concentrations (Ca, Mg, Sr, Na, Fe, and Mn) have been determined for the carbonate fraction of bulk samples from the late Oligocene Tikorangi Formation, a subsurface, mixed dolomite-calcite, cool-water limestone sequence in Taranaki Basin, New Zealand. While the occurrence of dolomite is rare in New Zealand Cenozoic carbonates, and in cool-water carbonates more generally, the dolomite in the Tikorangi carbonates is shown to have a dramatic effect on the "traditional" positioning of cool-water limestone fields within bivariate element plots. Rare undolomitised, wholly calcitic carbonate samples in the Tikorangi Formation have the following average composition: Mg 2800 ppm; Ca 319 100 ppm; Na 800 ppm; Fe 6300 ppm; Sr 2400 ppm; and Mn 300 ppm. Tikorangi Formation dolomite-rich samples (>15% dolomite) have average values of: Mg 53 400 ppm; Ca 290 400 ppm; Na 4700 ppm; Fe 28 100 ppm; Sr 5400 ppm; and Mn 500 ppm. Element-element plots for dolomite-bearing samples show elevated Mg, Na, and Sr values compared with most other low-Mg calcite New Zealand Cenozoic limestones. The increased trace element contents are directly attributable to the trace element-enriched nature of the burial-derived dolomites, termed here the "dolomite effect". Fe levels in the Tikorangi Formation carbonates far exceed both modern and ancient cool-water and warm-water analogues, while Sr values are also higher than those in modern Tasmanian cool-water carbonates, and approach modern Bahaman warm-water carbonate values. Trace element data used in conjunction with more traditional petrographic data have aided in the diagenetic interpretation of the carbonate-dominated Tikorangi sequence. The geochemical results have been particularly useful for providing more definitive evidence for deep burial dolomitisation of the deposits under the influence of marine-modified pore fluids

Computational Study of the Rovibrational Spectrum of CO₂-CS₂

A new intermolecular potential energy surface, rovibrational transition frequencies, and line strengths are computed for CO2-CS2. the potential is made by fitting energies obtained from explicitly correlated coupled-cluster calculations using an interpolating moving least squares method. the rovibrational Schrödinger equation is solved with a symmetry-adapted Lanczos algorithm and an uncoupled product basis set. All four intermolecular coordinates are included in the calculation. in agreement with previous experiments, the global minimum of the potential energy surface (PES) is cross shaped. the PES also has slipped-parallel minima. Rovibrational wavefunctions are localized in the cross minima and the slipped-parallel minima. Vibrational parent analysis was used to assign vibrational labels to rovibrational states. Tunneling occurs between the two cross minima. Because more than one symmetry operation interconverts the two wells, the symmetry (-oo) of the upper component of the tunneling doublet is different from the symmetry (-ee) of the tunneling coordinate. This unusual situation is due to the multidimensional nature of the double well tunneling. For the cross ground vibrational state, calculated rotational constants differ from their experimental counterparts by less than 0.0001 cm-1. Most rovibrational states were found to be incompatible with the standard effective rotational Hamiltonian often used to fit spectra. This appears to be due to coupling between internal and overall rotation of the dimer. a simple 2D model accounting for internal rotation was used for two cross-shaped fundamentals to obtain good fits