Evolutionary history and identification of conservation units in the giant otter, Pteronura brasiliensis.

The giant otter, Pteronura brasiliensis, occupies a range including the major drainage basins of South America, yet the degree of structure that exists within and among populations inhabiting these drainages is unknown. We sequenced portions of the mitochondrial DNA (mtDNA) cytochrome b (612 bp) and control region (383 bp) genes in order to determine patterns of genetic variation within the species. We found high levels of mtDNA haplotype diversity (h = 0.93 overall) and support for subdivision into four distinct groups of populations, representing important centers of genetic diversity and useful units for prioritizing conservation within the giant otter. We tested these results against the predictions of three hypotheses of Amazonian diversification (Pleistocene Refugia, Paleogeography, and Hydrogeology). While the phylogeographic pattern conformed to the predictions of the Refugia Hypothesis, molecular dating using a relaxed clock revealed the phylogroups diverged from one another between 1.69 and 0.84 Ma, ruling out the influence of Late Pleistocene glacial refugia. However, the role of Plio-Pleistocene climate change could not be rejected. While the molecular dating also makes the influence of geological arches according to the Paleogeography Hypothesis extremely unlikely, the recent Pliocene formation of the Fitzcarrald Arch and its effect of subsequently altering drainage pattern could not be rejected. The data presented here support the interactions of both climatic and hydrological changes resulting from geological activity in the Plio-Pleistocene, in shaping the phylogeographic structure of the giant otter

Magnetic properties of REE fluorcarbonate minerals and their implications for minerals processing

This is the final version. Available on open access from Elsevier via the DOI in this recordRare earth elements (REE) are considered as critical metals for electronics and green technology. The REE fluorcarbonates are one of the main REE ore minerals, common in many different types of REE deposit and yet some of their fundamental properties have still not been determined. This study measured the magnetic properties of pure REE fluorcarbonate single crystal minerals using a vibrating sample magnetometer (VSM) and determined their elemental compositions using electron probe microanalysis (EPMA). The results provide the first measurements of the magnetic behaviour and susceptibility of REE fluorcarbonates other than bastnäsite-(Ce). The magnetic susceptibility of REE fluorcarbonates varies systematically from one mineral to another and is highly dependent on the mineral chemistry. It is positive (paramagnetic) for bastnäsite-(Ce) and gradually decreases as the amount of Ca increases in parisite-(Ce), becoming negative (diamagnetic) for the Ca-rich member of the series, röntgenite. Synchysite-(Ce) is difficult to measure, generate good signal and acquire accurate readings because it practically always occurs as <5 mg crystals. Its magnetic susceptibility in samples from a REE ore deposit was experimentally determined by magnetic separation and checked by an associated study using a SQUID magnetometer, synchysite-(Ce) behaved as a diamagnetic mineral. This can be explained by the increase of Ca content and decrease of REE content, in addition to the variations in the layered structure common to the REE fluorcarbonate series minerals. Given the wide range of magnetic susceptibility of REE fluorcarbonates, it is important that the mineralogy is determined carefully before setting up a mineral processing flow sheet.Mkango Resources LtdNatural Environment Research Council (NERC

All-Sky spectrally matched UBVRI-ZY and u'g'r'i'z' magnitudes for stars in the Tycho2 catalog

We present fitted UBVRI-ZY and u'g'r'i'z' magnitudes, spectral types and distances for 2.4M stars, derived from synthetic photometry of a library spectrum that best matches the Tycho2 BtVt, NOMAD Rn and 2MASS JHK_{2/S} catalog magnitudes. We present similarly synthesized multi-filter magnitudes, types and distances for 4.8M stars with 2MASS and SDSS photometry to g<16 within the Sloan survey region, for Landolt and Sloan primary standards, and for Sloan Northern (PT) and Southern secondary standards. The synthetic magnitude zeropoints for BtVt, UBVRI, ZvYv, JHK_{2/S}, JHK_{MKO}, Stromgren uvby, Sloan u'g'r'i'z' and ugriz are calibrated on 20 calspec spectrophotometric standards. The UBVRI and ugriz zeropoints have dispersions of 1--3%, for standards covering a range of color from -0.3 < V-I < 4.6; those for other filters are in the range 2--5%. The spectrally matched fits to Tycho2 stars provide estimated 1-sigma errors per star of ~0.2, 0.15, 0.12, 0.10 and 0.08 mags respectively in either UBVRI or u'g'r'i'z'; those for at least 70% of the SDSS survey region to g<16 have estimated 1-sigma errors per star of ~0.2, 0.06, 0.04, 0.04, 0.05 in u'g'r'i'z' or UBVRI. The density of Tycho2 stars, averaging about 60 stars per square degree, provides sufficient stars to enable automatic flux calibrations for most digital images with fields of view of 0.5 degree or more. Using several such standards per field, automatic flux calibration can be achieved to a few percent in any filter, at any airmass, in most workable observing conditions, to facilitate inter-comparison of data from different sites, telescopes and instruments.Comment: 36 pages, 30 figures, 3 printed tables, several electronic tables, accepted PASP Dec 201

On the secondary star of the cataclysmic variable 1RXS J094432.1+035738

We present V and Rc band photometry and optical near-infrared spectroscopy of the cataclysmic variable 1RXS J094432.1+035738. We detected features of a cool secondary star, which can be modeled with a red dwarf of spectral type M2 (+0.5 -1.0) V at a distance of 433 +- 100 pc.Comment: Accepted for publication in Astronomy and Astrophysic

Light hadron spectroscopy with O(a) improved dynamical fermions

We present the first results for the static quark potential and the light hadron spectrum using dynamical fermions at $\beta=5.2$ using an O(a) improved Wilson fermion action together with the standard Wilson plaquette action for the gauge part. Sea quark masses were chosen such that the pseudoscalar-vector mass ratio, m_PS/m_V$, varies from 0.86 to 0.67. Finite-size effects are studied by using three different volumes, 8^3\cdot 24, 12^3\cdot 24 and 16^3\cdot 24. Comparing our results to previous ones obtained using the quenched approximation, we find evidence for sea quark effects in quantities like the static quark potential and the vector-pseudoscalar hyperfine splitting.Comment: 38 pages, 14 Postscript figure, LaTe

Feasibility of utilizing the 200-inch Hale telescope as a deep-space optical receiver

Capturing the very faint optical communications signals expected from the Mars Laser Communication Demonstration (MLCD) experiment to fly aboard the Mars Telecommunications Orbiter (MTO) in 2009 requires a sensitive receiver placed at the focus of a large collecting aperture. For the purpose of demonstrating the potential of deep-space optical communication, it makes sense to employ a large astronomical telescope as a temporary receiver. Because of its large collecting aperture, its reputation as a well-run instrument, and its relative convenience, the 200-inch Hale Telescope on Palomar Mountain is being considered as a demonstration optical 'antenna' for the experiment. However, use of the telescope in this manner presents unique challenges to be overcome, the greatest of which is pointing the telescope and maintaining the communication link to within a few degrees of the Sun. This paper presents our candidate approaches for adapting the Hale telescope to meet the demonstration requirements, modifications to the facilities and infrastructure, the derivation of requirements for baffles and filters to meet the near-Sun pointing objectives, and initial data on the potential of candidate modifications to meet the requirements

RSV-encoded NS2 promotes epithelial cell shedding and distal airway obstruction

Respiratory syncytial virus (RSV) infection is the major cause of bronchiolitis in young children. The factors that contribute to the increased propensity of RSV-induced distal airway disease compared with other commonly encountered respiratory viruses remain unclear. Here, we identified the RSV-encoded nonstructural 2 (NS2) protein as a viral genetic determinant for initiating RSV-induced distal airway obstruction. Infection of human cartilaginous airway epithelium (HAE) and a hamster model of disease with recombinant respiratory viruses revealed that NS2 promotes shedding of infected epithelial cells, resulting in two consequences of virus infection. First, epithelial cell shedding accelerated the reduction of virus titers, presumably by clearing virus-infected cells from airway mucosa. Second, epithelial cells shedding into the narrow-diameter bronchiolar airway lumens resulted in rapid accumulation of detached, pleomorphic epithelial cells, leading to acute distal airway obstruction. Together, these data indicate that RSV infection of the airway epithelium, via the action of NS2, promotes epithelial cell shedding, which not only accelerates viral clearance but also contributes to acute obstruction of the distal airways. Our results identify RSV NS2 as a contributing factor for the enhanced propensity of RSV to cause severe airway disease in young children and suggest NS2 as a potential therapeutic target for reducing the severity of distal airway disease

D-term inflation without cosmic strings

We present a superstring-inspired version of D-term inflation which does not lead to cosmic string formation and appears to satisfy the current CMB constraints. It differs from minimal D-term inflation by a second pair of charged superfields which makes the strings non-topological (semilocal). The strings are also BPS, so the scenario is expected to survive supergravity corrections. The second pair of charged superfields arises naturally in several brane and conifold scenarios, but its effect on cosmic string formation had not been noticed so far.Comment: 10 pages, uses REVTEX 4; minor typos corrected, references added, version to be publishe