Excavations for the Upper Labor Dam Site, Brackenridge Park, San Antonio, Bexar County, Texas

Upon notification, in 1995, that a portion of a Spanish Colonial acequia had been exposed in Brackenridge Park, the Parks and Recreation Department of the City of San Antonio entered into a contract with the Center for Archaeological Research (CAR) of the University of Texas at San Antonio to investigate and document the structure. In September of 1996, a team from CAR, utilizing a backhoe and operator provided by Parks and Recreation, began a limited investigation of the structure. The structure proved to be the dam for the Upper Labor and displayed two distinct construction periods, Spanish Colonial and post -1860. It was further documented that the structure acted as a diversion device rather than a full empoundment structure

The Relationship Between X-ray Luminosity and Duty Cycle for Dwarf Novae and their Specific Frequency in the Inner Galaxy

We measure the duty cycles for an existing sample of well observed, nearby dwarf novae using data from AAVSO, and present a quantitative empirical relation between the duty cycle of dwarf novae outbursts and the X-ray luminosity of the system in quiescence. We have found that $\log DC=0.63(\pm0.21)\times(\log L_{X}({\rm erg\,s^{-1}})-31.3)-0.95(\pm0.1)$, where DC stands for duty cycle. We note that there is intrinsic scatter in this relation greater than what is expected from purely statistical errors. Using the dwarf nova X-ray luminosity functions from \citet{Pretorius12} and \citet{Byckling10}, we compare this relation to the number of dwarf novae in the Galactic Bulge Survey which were identified through optical outbursts during an 8-day long monitoring campaign. We find a specific frequency of X-ray bright ($L_{X}>10^{31}\,{\rm erg\,s^{-1}}$) Cataclysmic Variables undergoing Dwarf Novae outbursts in the direction of the Galactic Bulge of $6.6\pm4.7\times10^{-5}\,M_{\odot}^{-1}$. Such a specific frequency would give a Solar neighborhood space density of long period CVs of $\rho=5.6\pm3.9\times10^{-6}\,$pc$^{-3}$. We advocate the use of specific frequency in future work, given that projects like LSST will detect DNe well outside the distance range over which $\rho\approx{\textrm const}$.Comment: 9 pagers, 4 figures Accepted for publication in MNRA

The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0

The All-Sky Automated Survey for Supernovae (ASAS-SN) is working towards imaging the entire visible sky every night to a depth of V~17 mag. The present data covers the sky and spans ~2-5~years with ~100-400 epochs of observation. The data should contain some ~1 million variable sources, and the ultimate goal is to have a database of these observations publicly accessible. We describe here a first step, a simple but unprecedented web interface https://asas-sn.osu.edu/ that provides an up to date aperture photometry light curve for any user-selected sky coordinate. Because the light curves are produced in real time, this web tool is relatively slow and can only be used for small samples of objects. However, it also imposes no selection bias on the part of the ASAS-SN team, allowing the user to obtain a light curve for any point on the celestial sphere. We present the tool, describe its capabilities, limitations, and known issues, and provide a few illustrative examples.Comment: 8 pages, 9 figures, submitted to PAS

HD 145263: Spectral Observations of Silica Debris Disk Formation via Extreme Space Weathering?

We report here time domain infrared spectroscopy and optical photometry of the HD145263 silica-rich circumstellar disk system taken from 2003 through 2014. We find an F4V host star surrounded by a stable, massive 1e22 - 1e23 kg (M_Moon to M_Mars) dust disk. No disk gas was detected, and the primary star was seen rotating with a rapid ~1.75 day period. After resolving a problem with previously reported observations, we find the silica, Mg-olivine, and Fe-pyroxene mineralogy of the dust disk to be stable throughout, and very unusual compared to the ferromagnesian silicates typically found in primordial and debris disks. By comparison with mid-infrared spectral features of primitive solar system dust, we explore the possibility that HD 145263's circumstellar dust mineralogy occurred with preferential destruction of Fe-bearing olivines, metal sulfides, and water ice in an initially comet-like mineral mix and their replacement by Fe-bearing pyroxenes, amorphous pyroxene, and silica. We reject models based on vaporizing optical stellar megaflares, aqueous alteration, or giant hypervelocity impacts as unable to produce the observed mineralogy. Scenarios involving unusually high Si abundances are at odds with the normal stellar absorption near-infrared feature strengths for Mg, Fe, and Si. Models involving intense space weathering of a thin surface patina via moderate (T < 1300 K) heating and energetic ion sputtering due to a stellar superflare from the F4V primary are consistent with the observations. The space weathered patina should be reddened, contain copious amounts of nanophase Fe, and should be transient on timescales of decades unless replenished.Comment: 41 Pages, 5 Figures, 5 Tables, Accepted for publication in the Astrophysical Journa

Respiratory tract infections among children younger than 5 years: Current management in Australian general practice

Objective: To explore the current management in Australian general practice of common respiratory tract infections (RTIs) in children younger than 5 years. Design, setting and participants: Analysis of data from a sample of 4522 general practitioners who participated in the Bettering the Evaluation and Care of Health (BEACH) cross-sectional survey, April 2007 to March 2012. Consultations with children younger than 5 years were analysed. Main outcome measures: GPs’ management of four common RTIs (acute upper RTI [URTI], acute bronchitis/bronchiolitis, acute tonsillitis, and pneumonia) in association with six management options: antibiotic medications; prescribed or supplied non-antibiotic medications; medications advised for over-the-counter purchase; referrals; pathology testing; and counselling. Results: Of 31 295 encounters recorded, at least one of the four selected paediatric RTIs was managed at 8157 encounters. URTI was managed 18.6 times per 100 GP patient encounters, bronchitis/bronchiolitis 4.2 times, acute tonsillitis 2.7 times, and pneumonia 0.6 times per 100 encounters. Antibiotics were prescribed most frequently for tonsillitis and least frequently for URTI. Male GPs prescribed antibiotics for URTI significantly more often than female GPs, while older GPs prescribed antibiotics for URTI more often than younger GPs. Conclusion: GP management of paediatric RTIs in Australia varied according to the clinical problem and with age and sex of the GP. Further research into parents’ and health professionals’ attitudes and practices regarding the role of antibiotics, over-the-counter medications, and hygiene will help maintain favourable management practices

Test Excavations at the Culebra Creek Site, 41BX126, Bexar County, Texas

Archaeological test excavations were undertaken at 4IBX126 on Culebra Creek to offset the impact from a proposed Texas Department of Transportation (TxDOT) highway improvement project on Loop 1604 in northwest Bexar County. Archaeological investigations were conducted in three field seasons: the first two seasons were conducted by TxDOT archaeologists and the third was directed by personnel from the Center for Archaeological Research (CAR) of The University of Texas at San Antonio. During the three projects, 55 hand-dug units, 29 backhoe trenches, 36 shovel tests, and eight Gradall trenches were excavated. Seventeen features were recorded; 25 radiocarbon assays were conducted; over 59,000 lithic artifacts were recovered and analyzed; 1,655 liters of sediment float samples were processed; 3,337 kg of burned rock were analyzed; and nearly 300 g of fatmal material and 25 archaeomagnetic samples were analyzed. The testing revealed utilization of the site in the Early, Middle, and Late Archaic periods. The analysis of materials and results of all three field efforts are presented in this single volume. Geoarchaeological investigations show that four terraces (TO, Tl, T2, and T3) in the immediate site area accumulated from the Late Pleistocene through the Holocene. Five Stratigraphic Units (I-V) make up these terraces and overlap one another. The T2 terrace is composed of Stratigraphic Units IT, ill, and IV, while the Tl terrace consists mostly of Stratigraphic Units IV and V. Archaeological materials were discovered in situ within the Tl and T3 terraces and primarily within Stratigraphic Units ill and IV. Radiocarbon assays indicate that Stratigraphic Unit IV formed between at least 4000-2000 B.P., Stratigraphic Unit ill accumulated between approximately 11,500-4000 B.P., and Stratigraphic Unit IT was accreting at least 17,500 years ago. Too little evidence exists to determine the full time ranges of sediment accumulation, and whether significant temporal gaps exist between the sedimentation of these geological units. Archaeological excavations focused on three separate areas: A, B, and C. Area A is a new right-of-way east of the existing right-of-way. Excavations in this area defined a Late Archaic Montell component dating to approximately 2700 B.P. These materials include two burned rock features in situ within Unit IV on the scarp of the T2 terrace. This area probably was occupied by a small residential group during the Late Archaic period. Area B is east of Loop 1604 in the existing right-of-way and on the T2 terrace. Area B contains a Middle Archaic Nolan component in the upper portion of Stratigraphic Unit ill, below a Late Archaic burned rock midden with a central subsurface oven in Unit IV. Area C is in the existing right-of-way west of Loop 1604. Excavations in this area investigated the possibility of an intact Early Archaic occupation; however, no evidence of one was found. In Area B, the Nolan component consisted of lithic artifacts scattered among small burned rock features that probably served as hearths. This component is radiocarbon dated to approximately 4600 B.P. The Late Archaic burned rock midden was apparently used between 4000 B.P. and 2000 B.P. Subfeatures within the central oven indicate multiple cooking events. Ethnographic evidence suggests earth ovens contained food wrapped with insulating material over a layer of hot rocks heated by a coal bed. This was capped with dirt to seal the oven. When cooking was complete, the earth cap is removed to reach the food. CAR conducted earth-oven hot-rock experiments which indicated that local limestone could be used once or at the most twice. Local hot-rock cooking should generate a great deal of burned limestone debris. The framework ofthe feature at 41BX126 represents the cap and rock heating-element dumpings from separate cooking events as well as a few small intact burned rock features that served as ovens or hearths. At the base of the midden were a few depressions that may represent borrow pits used to obtain sediment for the central oven cap. Mixing of temporally distinct artifacts from the Nolan and later occupations occurs in and beyond the midden due to sediment excavation and transportation across the site, and redeposition of materials through erosion of materials off the framework

The Chandra Galactic Bulge Survey: optical catalogue and point-source counterparts to X-ray sources

As part of the Chandra Galactic Bulge Survey (GBS), we present a catalogue of optical sources in the GBS footprint. This consists of two regions centered at Galactic latitude b = 1.5 degrees above and below the Galactic Centre, spanning (l x b) = (6x1) degrees. The catalogue consists of 2 or more epochs of observations for each line of sight in r', i' and H{\alpha} filters. It is complete down to r' = 20.2 and i' = 19.2 mag; the mean 5{\sigma} depth is r' = 22.5 and i' = 21.1 mag. The mean root-mean-square residuals of the astrometric solutions is 0.04 arcsec. We cross-correlate this optical catalogue with the 1640 unique X-ray sources detected in Chandra observations of the GBS area, and find candidate optical counterparts to 1480 X-ray sources. We use a false alarm probability analysis to estimate the contamination by interlopers, and expect ~ 10 per cent of optical counterparts to be chance alignments. To determine the most likely counterpart for each X-ray source, we compute the likelihood ratio for all optical sources within the 4{\sigma} X-ray error circle. This analysis yields 1480 potential counterparts (~ 90 per cent of the sample). 584 counterparts have saturated photometry (r'<17, i'<16), indicating these objects are likely foreground sources and the real counterparts. 171 candidate counterparts are detected only in the i'-band. These sources are good qLMXB and CV candidates as they are X-ray bright and likely located in the Bulge.Comment: 18 pages, 18 figures. Published in MNRAS. 2016MNRAS.458.4530

A dynamical model of surrogate reactions

A new dynamical model is developed to describe the whole process of surrogate reactions; transfer of several nucleons at an initial stage, thermal equilibration of residues leading to washing out of shell effects and decay of populated compound nuclei are treated in a unified framework. Multi-dimensional Langevin equations are employed to describe time-evolution of collective coordinates with a time-dependent potential energy surface corresponding to different stages of surrogate reactions. The new model is capable of calculating spin distributions of the compound nuclei, one of the most important quantity in the surrogate technique. Furthermore, various observables of surrogate reactions can be calculated, e.g., energy and angular distribution of ejectile, and mass distributions of fission fragments. These features are important to assess validity of the proposed model itself, to understand mechanisms of the surrogate reactions and to determine unknown parameters of the model. It is found that spin distributions of compound nuclei produced in $^{18}$O+$^{238}$U $\rightarrow ^{16}$O+$^{240*}$U and $^{18}$O+$^{236}$U $\rightarrow ^{16}$O+$^{238*}$U reactions are equivalent and much less than 10$\hbar$, therefore satisfy conditions proposed by Chiba and Iwamoto (PRC 81, 044604(2010)) if they are used as a pair in the surrogate ratio method.Comment: 17 pages, 5 figure

Passive sorting of asteroid material using solar radiation pressure

Understanding dust dynamics in asteroid environments is key for future science missions to asteroids and, in the long-term, also for asteroid exploitation. This paper proposes a novel way of manipulating asteroid material by means of solar radiation pressure (SRP). We envisage a method for passively sorting material as a function of its grain size where SRP is used as a passive in-situ ‘mass spec-trometer’. The analysis shows that this novel method allows an effective sorting of regolith material. This has immediate applications for sample return, and in-situ resource utilisation to separate different regolith particle sizes

Spectroscopic classification of X-ray sources in the Galactic Bulge Survey

We present the classification of 26 optical counterparts to X-ray sources discovered in the Galactic Bulge Survey. We use (time-resolved) photometric and spectroscopic observations to classify the X-ray sources based on their multi-wavelength properties. We find a variety of source classes, spanning different phases of stellar/binary evolution. We classify CX21 as a quiescent cataclysmic variable (CV) below the period gap, and CX118 as a high accretion rate (nova-like) CV. CXB12 displays excess UV emission, and could contain a compact object with a giant star companion, making it a candidate symbiotic binary or quiescent low mass X-ray binary (although other scenarios cannot be ruled out). CXB34 is a magnetic CV (polar) that shows photometric evidence for a change in accretion state. The magnetic classification is based on the detection of X-ray pulsations with a period of 81 $\pm$ 2 min. CXB42 is identified as a young stellar object, namely a weak-lined T Tauri star exhibiting (to date unexplained) UX Ori-like photometric variability. The optical spectrum of CXB43 contains two (resolved) unidentified double-peaked emission lines. No known scenario, such as an AGN or symbiotic binary, can easily explain its characteristics. We additionally classify 20 objects as likely active stars based on optical spectroscopy, their X-ray to optical flux ratios and photometric variability. In 4 cases we identify the sources as binary stars.Comment: Accepted for publication in MNRA