3,412 research outputs found

    Infrared interferometry to spatially and spectrally resolve jets in X-ray binaries

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    Infrared interferometry is a new frontier for precision ground based observing, with new instrumentation achieving milliarcsecond (mas) spatial resolutions for faint sources, along with astrometry on the order of 10 microarcseconds. This technique has already led to breakthroughs in the observations of the supermassive black hole at the Galactic centre and its orbiting stars, AGN, and exo-planets, and can be employed for studying X-ray binaries (XRBs), microquasars in particular. Beyond constraining the orbital parameters of the system using the centroid wobble and spatially resolving jet discrete ejections on mas scales, we also propose a novel method to discern between the various components contributing to the infrared bands: accretion disk, jets and companion star. We demonstrate that the GRAVITY instrument on the Very Large Telescope Interferometer (VLTI) should be able to detect a centroid shift in a number of sources, opening a new avenue of exploration for the myriad of transients expected to be discovered in the coming decade of radio all-sky surveys. We also present the first proof-of-concept GRAVITY observation of a low-mass X-ray binary transient, MAXI J1820+070, to search for extended jets on mas scales. We place the tightest constraints yet via direct imaging on the size of the infrared emitting region of the compact jet in a hard state XRB.Comment: 12 Pages, 3 figures, accepted for publication in MNRA

    Archeological Survey and Testing of Selected Prehistoric Sites along FM 481, Zavala County, Texas

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    Between April 1981 and December 1982, Texas Department of Transportation (TxDOT) personnel conducted archeological fieldwork along an approximately 13-km segment of FM 481 in northwest Zavala County. The work was part of an evaluation of the impacts of road improvements to a series of sites along the right-of-way. All of the sites but one (41ZV202) were found not to be eligible for listing on the National Register of Historic Places and not to warrant designations as State Archeological Landmarks. Additional work, not reported here, was later conducted at 41ZV202. As part of Work Authorization #57015PD004, the Environmental Affairs Division of TxDOT contracted with the Center for Archaeological Research (CAR) of The University of Texas at San Antonio to report on the fieldwork carried out at the sites during the early 1980s, identify data types warranting additional research, and conduct the appropriate analyses. The current document provides descriptions of the work undertaken along FM 481, assesses the analytical utility of the data types recovered, and reports the results of limited new research of selected data types. Note that all documentation of the project, including notes, photographs, and a sample of recovered artifacts are curated at the Center for Archaeological Research. The sample includes all projectile points, as well as other chipped and ground stone tools, and the debitage recovered for a 10% sample of proveniences

    Archaeological Survey for the Proposed Salado Creek Hike and Bike Trail, City of San Antonio, Bexar County, Texas

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    In November of 2002 and March of 2003, a crew from the Center for Archaeological Research at The University of Texas at San Antonio conducted archeological and geoarcheological investigations along Salado Creek in San Antonio, Bexar County, Texas. The purpose of this fieldwork was to investigate, using shovel testing and backhoe trenching, the impact of the proposed construction of an approximately three-mile-long hike and bike trail along the creek. The work included testing for the presence of the historic Alsbury Family Cemetery and Homestead that may be in close proximity to the trail’s right-of-way. Work was performed under contract with HNTB Corporation of San Antonio. This work was conducted under Texas Antiquities Permit No. 2917, with Steve A. Tomka serving as Principal Investigator. Shovel testing and backhoe trenching yielded no significant archeological deposits. No cultural material was collected during the survey. A backhoe trench and shovel tests placed along the trail’s path in the vicinity of the cemetery encountered no signs of graves and archival research suggests the cemetery is well outside the trail right-of-way. It is believed that locating the Alsbury Family Cemetery may require pedestrian survey and subsurface investigations that are outside the scope of this project. Finally, it is recommended that the construction of the proposed hike and bike trail proceed as planned since it will not impact intact cultural deposits of significant research potential

    Archaeology of the Planned Location of the Toyota Motor Manufacturing Plant, San Antonio, Bexar County, Texas

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    From October 2002 to January 2004, the Center for Archaeological Research (CAR) of The University of Texas at San Antonio conducted archaeological investigations for the City of San Antonio in a 2,570.25-acre project area that is the future site of the San Antonio Toyota Motor Manufacturing Plant. The work was conducted under Texas Antiquities Permit No. 2982 with Dr. Steve A. Tomka, CAR Director, serving as Principal Investigator. The project included the reconnaissance of over 500 acres of the project area, the excavation of 376 shovel tests, 250 mechanical auger borings, and 42 backhoe and Gradall trenches. The backhoe and Gradall trenches were dug for geoarchaeological investigations and in one instance to search for a presumed historic cemetery. Reassessment for National Register of Historic Places and State Archeological Landmark status was conducted for 16 previously documented archaeological sites (41BX125, 41BX349, 41BX652, 41BX653, 41BX654, 41BX655, 41BX656, 41BX657, 41BX658, 41BX659, 41BX660, 41BX661, 41BX662, 41BX676, 41BX681, and 41BX832) and five newly identified sites (41BX1571–41BX1575). Of the 21 sites examined during this project, 12 are prehistoric, seven are historic and two have both prehistoric and historic components. The prehistoric sites are lithic and burned rock scatters, possibly the remnants of campsites. Diagnostic artifacts found in previous surveys indicate Archaic and Late Prehistoric time frames. The historic sites present are farmstead-ranch complexes including residential structures and outbuildings. Also encountered were tenant farmer residences and a small brick kiln. The historic components are primarily late-nineteenth and early-twentieth-century, although original surveys noted early-nineteenth-century artifacts. All artifacts collected are curated at the Center for Archaeological Research laboratory facility

    Avoidance of wind farms by harbour seals is limited to pile driving activities

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    DJFR, GH, VMJ and BM were funded by the UK Department of Energy and Climate Change (DECC) as part of their Offshore Energy Strategic Environmental Assessment programme. DT and GH were also funded by NERC/Defra EBAO NE/J004243/1. ELJ was funded under Scottish Government grant MMSS001/01. This work was also supported by National Capability funding from the Natural Environment Research Council to SMRU (grant no. SMRU1001). Tags and their deployment in the Thames in 2006 and The Wash were funded by DECC. Tags and their deployment in the Thames in 2012 were commissioned by Zoological Society London, with funding from BBC Wildlife Fund and Sita Trust.1. As part of global efforts to reduce dependence on carbon-based energy sources there has been a rapid increase in the installation of renewable energy devices. The installation and operation of these devices can result in conflicts with wildlife. In the marine environment, mammals may avoid wind farms that are under construction or operating. Such avoidance may lead to more time spent travelling or displacement from key habitats. A paucity of data on at-sea movements of marine mammals around wind farms limits our understanding of the nature of their potential impacts. 2. Here, we present the results of a telemetry study on harbour seals Phoca vitulina in The Wash, south-east England, an area where wind farms are being constructed using impact pile driving. We investigated whether seals avoid wind farms during operation, construction in its entirety, or during piling activity. The study was carried out using historical telemetry data collected prior to any wind farm development and telemetry data collected in 2012 during the construction of one wind farm and the operation of another. 3. Within an operational wind farm, there was a close-to-significant increase in seal usage compared to prior to wind farm development. However, the wind farm was at the edge of a large area of increased usage, so the presence of the wind farm was unlikely to be the cause. 4. There was no significant displacement during construction as a whole. However, during piling, seal usage (abundance) was significantly reduced up to 25 km from the piling activity; within 25 km of the centre of the wind farm, there was a 19 to 83% (95% confidence intervals) decrease in usage compared to during breaks in piling, equating to a mean estimated displacement of 440 individuals. This amounts to significant displacement starting from predicted received levels of between 166 and 178 dB re 1 μPa(p·p). Displacement was limited to piling activity; within 2 h of cessation of pile driving, seals were distributed as per the non-piling scenario. 5. Synthesis and applications. Our spatial and temporal quantification of avoidance of wind farms by harbour seals is critical to reduce uncertainty and increase robustness in environmental impact assessments of future developments. Specifically, the results will allow policymakers to produce industry guidance on the likelihood of displacement of seals in response to pile driving; the relationship between sound levels and avoidance rates; and the duration of any avoidance, thus allowing far more accurate environmental assessments to be carried out during the consenting process. Further, our results can be used to inform mitigation strategies in terms of both the sound levels likely to cause displacement and what temporal patterns of piling would minimize the magnitude of the energetic impacts of displacement.Publisher PDFPeer reviewe

    Toward open sharing of task-based fMRI data: the OpenfMRI project

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    The large-scale sharing of task-based functional neuroimaging data has the potential to allow novel insights into the organization of mental function in the brain, but the field of neuroimaging has lagged behind other areas of bioscience in the development of data sharing resources. This paper describes the OpenFMRI project (accessible online at http://www.openfmri.org), which aims to provide the neuroimaging community with a resource to support open sharing of task-based fMRI studies. We describe the motivation behind the project, focusing particularly on how this project addresses some of the well-known challenges to sharing of task-based fMRI data. Results from a preliminary analysis of the current database are presented, which demonstrate the ability to classify between task contrasts with high generalization accuracy across subjects, and the ability to identify individual subjects from their activation maps with moderately high accuracy. Clustering analyses show that the similarity relations between statistical maps have a somewhat orderly relation to the mental functions engaged by the relevant tasks. These results highlight the potential of the project to support large-scale multivariate analyses of the relation between mental processes and brain function

    Shared decision making in patients with low risk chest pain: prospective randomized pragmatic trial.

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    OBJECTIVE: To compare the effectiveness of shared decision making with usual care in choice of admission for observation and further cardiac testing or for referral for outpatient evaluation in patients with possible acute coronary syndrome. DESIGN: Multicenter pragmatic parallel randomized controlled trial. SETTING: Six emergency departments in the United States. PARTICIPANTS: 898 adults (aged \u3e17 years) with a primary complaint of chest pain who were being considered for admission to an observation unit for cardiac testing (451 were allocated to the decision aid and 447 to usual care), and 361 emergency clinicians (emergency physicians, nurse practitioners, and physician assistants) caring for patients with chest pain. INTERVENTIONS: Patients were randomly assigned (1:1) by an electronic, web based system to shared decision making facilitated by a decision aid or to usual care. The primary outcome, selected by patient and caregiver advisers, was patient knowledge of their risk for acute coronary syndrome and options for care; secondary outcomes were involvement in the decision to be admitted, proportion of patients admitted for cardiac testing, and the 30 day rate of major adverse cardiac events. RESULTS: Compared with the usual care arm, patients in the decision aid arm had greater knowledge of their risk for acute coronary syndrome and options for care (questions correct: decision aid, 4.2 v usual care, 3.6; mean difference 0.66, 95% confidence interval 0.46 to 0.86), were more involved in the decision (observing patient involvement scores: decision aid, 18.3 v usual care, 7.9; 10.3, 9.1 to 11.5), and less frequently decided with their clinician to be admitted for cardiac testing (decision aid, 37% v usual care, 52%; absolute difference 15%; P CONCLUSIONS: Use of a decision aid in patients at low risk for acute coronary syndrome increased patient knowledge about their risk, increased engagement, and safely decreased the rate of admission to an observation unit for cardiac testing.Trial registration ClinicalTrials.gov NCT01969240

    Archeological Testing of Sites 41GD113 and 41GD114 in Goliad County, Texas

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    Archeological testing of two previously identified prehistoric archeological sites in Goliad County, Texas, was performed by the Center for Archaeological Research (CAR) at The University of Texas at San Antonio. Testing examined 41GD113 and 41GD114 to determine their potential eligibility for listing on the National Register of Historic Places (NRHP) and whether they warranted designation as State Archeological Landmarks (SAL) . The work was performed for the Texas Department of Transportation (TxDOT) on July 24–August 2, 2002. Archeological testing was performed in relation to a proposed highway realignment to avoid the Noble Cemetery currently adjacent U.S. Highway 59. These investigations were conducted under Texas Antiquities Permit No. 2899, with Dr. Raymond P. Mauldin serving as Principal Investigator. 41GD113 is a Late Archaic site that is a palimpsest deposit of multiple, probably short-term, occupations. Five backhoe trenches and seven 1-x-1-m test units were excavated on this site. Geoarcheological investigations identified the site as a floodplain setting subject to periodic, fine, low-energy deposition. No intact features were identified, although fire-cracked rock was present and is almost certainly derived from cultural thermal use. A single late stage biface fragment, three flake tools, one core, and a relatively small debitage assemblage (n=866) was recovered. Most of these lithics came from two excavation units within intact deposits and another from a highly disturbed context. No diagnostic artifacts were encountered. The few faunal remains recovered cannot be unambiguously associated with past human activity. The portion of 41GD114 within the TxDOT right-of-way was extensively mechanically disturbed prior to these testing efforts. Three backhoe trenches and two 1-x-1-m test units were excavated on this site. Soils in the test units were shallow and encountered bedrock or gravel deposits at approximately 60 cm below surface. No tools or diagnostic artifacts were recovered and only 65 pieces of debitage were collected from controlled excavations. Subsequent to laboratory analyses, natural gravels, gastropods, and mussel shell remains from 41GD113 were discarded. All of the magnetic susceptibility samples from 41GD113 and 41GD114 were discarded following analysis. The entire assemblage from 41GD114 also was disposed of after analyses and will not be curated. All discarded materials were disposed of following proper artifact disposal procedures with the pre-approval of TxDOT and the Texas Historical Commission. All other materials and samples from 41GD113 were curated at the CAR permanent curation facility. Following the field investigation and analyses by CAR, neither 41GD113 nor 41GD114 is considered to be eligible for nomination for NRHP listing nor warrant designation as a SAL. Based on this testing effort no additional archeological investigations are considered necessary and it is recommended that construction of the proposed highway bypass be allowed to proceed

    Markers of Inflammation, Coagulation, and Renal Function Are Elevated in Adults with HIV Infection

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    (See the article by Kalayjian et al, on pages 1796-1805, and the editorial commentary by Dubé and Sattler, on pages 1783-1785.) Background. Human immunodeficiency virus (HIV) replication and immune activation may increase inflammation and coagulation biomarkers. Limited data exist comparing such biomarkers in persons with and without HIV infection. Methods. For persons 45-76 years of age, levels of high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, D-dimer, and cystatin C were compared in 494 HIV-infected individuals in the Strategies for Management of Anti-Retroviral Therapy (SMART) study and 5386 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) study. For persons 33-44 years of age, hsCRP and IL-6 levels were compared in 287 participants in the SMART study and 3231 participants in the Coronary Artery Development in Young Adults (CARDIA) study. Results. hsCRP and IL-6 levels were 55% (P<.001) and 62% (P<.001) higher among HIV-infected participants than among CARDIA study participants. Compared with levels noted in MESA study participants, hsCRP, IL-6, D-dimer, and cystatin C levels were 50%, 152%, 94%, and 27% higher, respectively (P<.001 , for each), among HIV-infected participants. HIV-infected participants receiving antiretroviral therapy who had HIV RNA levels ≤400 copies/mL had levels higher (by 21% to 60%) (P<.001) than those in the general population, for all biomarkers. Conclusions. hsCRP, IL-6, D-dimer, and cystatin C levels are elevated in persons with HIV infection and remain so even after HIV RNA levels are suppressed with antiretroviral therapy. Additional research is needed on the pathophysiology of HIV-induced activation of inflammatory and coagulation pathways, to guide potential intervention
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