68 research outputs found
Significance Testing Of Archeological Sites 41SR242, The Cornelio Alvarez SR. Site, Starr County, Texas
The Texas Department of Transportation (TxDOT), conducted National Register of Historic Places (NRHP) eligibility testing of the Cornelio Alvarez Sr. site (41SR242) as part of the State Loop (SL) 195 project (Project) (CSJ: 3632-01-001) in Starr County, Texas. Subsequent to the field investigations, SWCA Environmental Consultants (SWCA) conducted artifact analysis, reporting, and curation preparation for the multi-component historic and prehistoric site. Investigations were conducted in compliance with Section 106 of the National Historic Preservation Act (54 United State Code 30601) and the Antiquities Code of Texas (9 Natural Resources Code). The investigations assessed the siteâs eligibility for listing on the NRHP (36 Code of Federal Regulations 60.4) and for designation as a State Antiquities Landmark (SAL; 13 Texas Administrative Code 26.8, 26.12). Christopher W. Ringstaff served as Principal Investigator under Texas Antiquities Permit Number 7912. TxDOT conducted the field investigations were from February 20â24, 2017, and April 10â14, 2017.
Site 41SR242 is primarily a Middle to Late Archaic site with lesser Late Prehistoric and perhaps earlier components. The open occupational site is located on an upland margin landform in a tributary valley a few miles from the Rio Grande. The investigations revealed material assemblages consisting of diffusely scattered burned rock, debitage, and lithic tools, which were predominantly recovered from a 30- to 50- cm-thick stratum of mixed artifacts. However, a few concentrations of artifacts were identified, and each location yielded isolated intact features. Formation and post-depositional processes are generally not conducive to preservation of intact archeological surfaces, patterns, or site structure. Although the overall site lacks integrity and potential data yield, isolated discrete behavioral loci are present. Therefore, site 41SR242 is recommended as eligible for the NRHP and as an SAL. This recommendation pertains to the portions of the site within the APE. The site extends beyond the APE, and the areas outside of the APE have not been evaluated
Significance Testing of Archeological Site 41SR242, The Cornelio Alvarez Sr. Site, Starr County, Texas
The Texas Department of Transportation (TxDOT), conducted National Register of Historic Places (NRHP) eligibility testing of the Cornelio Alvarez Sr. site (41SR242) as part of the State Loop (SL) 195 project (Project) (CSJ: 3632-01-001) in Starr County, Texas. Subsequent to the field investigations, SWCA Environmental Consultants (SWCA) conducted artifact analysis, reporting, and curation preparation for the multi-component historic and prehistoric site. Investigations were conducted in compliance with Section 106 of the National Historic Preservation Act (54 United State Code 30601) and the Antiquities Code of Texas (9 Natural Resources Code). The investigations assessed the siteâs eligibility for listing on the NRHP (36 Code of Federal Regulations 60.4) and for designation as a State Antiquities Landmark (SAL; 13 Texas Administrative Code 26.8, 26.12). Christopher W. Ringstaff served as Principal Investigator under Texas Antiquities Permit Number 7912. TxDOT conducted the field investigations were from February 20â24, 2017, and April 10â14, 2017.
Site 41SR242 is primarily a Middle to Late Archaic site with lesser Late Prehistoric and perhaps earlier components. The open occupational site is located on an upland margin landform in a tributary valley a few miles from the Rio Grande. The investigations revealed material assemblages consisting of diffusely scattered burned rock, debitage, and lithic tools, which were predominantly recovered from a 30- to 50-cm-thick stratum of mixed artifacts. However, a few concentrations of artifacts were identified, and each location yielded isolated intact features. Formation and post-depositional processes are generally not conducive to preservation of intact archeological surfaces, patterns, or site structure. Although the overall site lacks integrity and potential data yield, isolated discrete behavioral loci are present. Therefore, site 41SR242 is recommended as eligible for the NRHP and as an SAL. This recommendation pertains to the portions of the site within the APE. The site extends beyond the APE, and the areas outside of the APE have not been evaluated
Virtual Texture Generated using Elastomeric Conductive Block Copolymer in Wireless Multimodal Haptic Glove.
Haptic devices are in general more adept at mimicking the bulk properties of materials than they are at mimicking the surface properties. This paper describes a haptic glove capable of producing sensations reminiscent of three types of near-surface properties: hardness, temperature, and roughness. To accomplish this mixed mode of stimulation, three types of haptic actuators were combined: vibrotactile motors, thermoelectric devices, and electrotactile electrodes made from a stretchable conductive polymer synthesized in our laboratory. This polymer consisted of a stretchable polyanion which served as a scaffold for the polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT). The scaffold was synthesized using controlled radical polymerization to afford material of low dispersity, relatively high conductivity (0.1 S cm-1), and low impedance relative to metals. The glove was equipped with flex sensors to make it possible to control a robotic hand and a hand in virtual reality (VR). In psychophysical experiments, human participants were able to discern combinations of electrotactile, vibrotactile, and thermal stimulation in VR. Participants trained to associate these sensations with roughness, hardness, and temperature had an overall accuracy of 98%, while untrained participants had an accuracy of 85%. Sensations could similarly be conveyed using a robotic hand equipped with sensors for pressure and temperature
Inhibition of Cholinergic Signaling Causes Apoptosis in Human Bronchioalveolar Carcinoma
Recent case-controlled clinical studies show that bronchioalveolar carcinomas (BAC) are correlated with smoking. Nicotine, the addictive component of cigarettes, accelerates cell proliferation through nicotinic acetylcholine receptors (nAChR). In this study, we show that human BACs produce acetylcholine (ACh) and contain several cholinergic factors including acetylcholinesterase (AChE), choline acetyltransferase (ChAT), choline transporter 1 (CHT1, SLC5A7), vesicular acetylcholine transporter (VAChT, SLC18A3), and nACh receptors (AChRs, CHRNAs). Nicotine increased the production of ACh in human BACs, and ACh acts as a growth factor for these cells. Nicotine-induced ACh production was mediated by α7-, α3ÎČ2-, and ÎČ3-nAChRs, ChAT and VAChT pathways. We observed that nicotine upregulated ChAT and VAChT. Therefore, we conjectured that VAChT antagonists, such as vesamicol, may suppress the growth of human BACs. Vesamicol induced potent apoptosis of human BACs in cell culture and nude mice models. Vesamicol did not have any effect on EGF or insulin-like growth factor-IIâinduced growth of human BACs. siRNA-mediated attenuation of VAChT reversed the apoptotic activity of vesamicol. We also observed that vesamicol inhibited Akt phosphorylation during cell death and that overexpression of constitutively active Akt reversed the apoptotic activity of vesamicol. Taken together, our results suggested that disruption of nicotine-induced cholinergic signaling by agents such as vesamicol may have applications in BAC therapy
YSOVAR: Mid-infrared Variability Among YSOs in the Star Formation Region GGD 12-15
S. J. Wolk, et al., âYSOVAR: Mid-infrared Variability Among YSOs in the Star Formation Region GGD 12-15â, The Astronomical Journal, Vol. 150(5), October 2015. © 2015. The American Astronomical Society. All rights reserved.We present an IR-monitoring survey with the Space Telescope of the star forming region GGD 12-15. Over 1000 objects were monitored including about 350 objects within the central 5 arcminutes which is found to be especially dense in cluster members. The monitoring took place over 38 days and is part of the Young Stellar Object VARiability (YSOVAR) project. The region was also the subject of a contemporaneous 67ks observation. The field includes 119 previously identified pre-main sequence star candidates. X-rays are detected from 164 objects, 90 of which are identified with cluster members. Overall, we find that about half the objects in the central 5 arcminutes are young stellar objects based on a combination of their spectral energy distribution, IR variability and X-ray emission. Most of the stars with IR excess relative to a photosphere show large amplitude (>0.1 mag) mid-IR variability. There are 39 periodic sources, all but one of these is found to be a cluster member. Almost half of the periodic sources do not show IR excesses. Overall, more than 85% of the Class I, flat spectrum, and Class II sources are found to vary. The amplitude of the variability is larger in more embedded young stellar objects. Most of the Class~I/II objects exhibit redder colors in a fainter state, compatible with time-variable extinction. A few become bluer when fainter, which can be explained with significant changes in the structure of the inner disk. A search for changes in the IR due to X-ray events is carried out, but the low number of flares prevented an analysis of the direct impact of X-ray flares on the IR lightcurves. However, we find that X-ray detected Class II sources have longer timescales for change in the mid-IR than a similar set of non-X-ray detected Class IIs.Peer reviewe
Accretion, Outflows, and Winds of Magnetized Stars
Many types of stars have strong magnetic fields that can dynamically
influence the flow of circumstellar matter. In stars with accretion disks, the
stellar magnetic field can truncate the inner disk and determine the paths that
matter can take to flow onto the star. These paths are different in stars with
different magnetospheres and periods of rotation. External field lines of the
magnetosphere may inflate and produce favorable conditions for outflows from
the disk-magnetosphere boundary. Outflows can be particularly strong in the
propeller regime, wherein a star rotates more rapidly than the inner disk.
Outflows may also form at the disk-magnetosphere boundary of slowly rotating
stars, if the magnetosphere is compressed by the accreting matter. In isolated,
strongly magnetized stars, the magnetic field can influence formation and/or
propagation of stellar wind outflows. Winds from low-mass, solar-type stars may
be either thermally or magnetically driven, while winds from massive, luminous
O and B type stars are radiatively driven. In all of these cases, the magnetic
field influences matter flow from the stars and determines many observational
properties. In this chapter we review recent studies of accretion, outflows,
and winds of magnetized stars with a focus on three main topics: (1) accretion
onto magnetized stars; (2) outflows from the disk-magnetosphere boundary; and
(3) winds from isolated massive magnetized stars. We show results obtained from
global magnetohydrodynamic simulations and, in a number of cases compare global
simulations with observations.Comment: 60 pages, 44 figure
YSOVAR: mid-infrared variability of young stellar objects and their disks in the cluster IRAS 20050+2720
K. Poppenhaeger, et al., âYSOVAR: mid-infrared variability of young stellar objects and their disks in the cluster IRAS 20050+2720â, The Astronomical Journal, Vol. 150(4), September 2015. © 2015. The American Astronomical Society. All rights reserved.We present a time-variability study of young stellar objects in the cluster IRAS 20050+2720, performed at 3.6 and 4.5 micron with the Spitzer Space Telescope; this study is part of the Young Stellar Object VARiability project (YSOVAR). We have collected light curves for 181 cluster members over 40 days. We find a high variability fraction among embedded cluster members of ca. 70%, whereas young stars without a detectable disk display variability less often (in ca. 50% of the cases) and with lower amplitudes. We detect periodic variability for 33 sources with periods primarily in the range of 2-6 days. Practically all embedded periodic sources display additional variability on top of their periodicity. Furthermore, we analyze the slopes of the tracks that our sources span in the color-magnitude diagram (CMD). We find that sources with long variability time scales tend to display CMD slopes that are at least partially influenced by accretion processes, while sources with short variability time scales tend to display extinction-dominated slopes. We find a tentative trend of X-ray detected cluster members to vary on longer time scales than the X-ray undetected members.Peer reviewe
Near-Infrared Variability in the Orion Nebula Cluster
Using the United Kingdom Infrared Telescope on Mauna Kea, we have carried out
a new near-infrared J, H, K monitoring survey of almost a square degree of the
star-forming Orion Nebula Cluster with observations on 120 nights over three
observing seasons, spanning a total of 894 days. We monitored ~15,000 stars
down to J=20 using the WFCAM instrument, and have extracted 1203 significantly
variable stars from our data. By studying variability in young stellar objects
(YSOs) in the H-K, K color-magnitude diagram, we are able to distinguish
between physical mechanisms of variability. Many variables show color behavior
indicating either dust-extinction or disk/accretion activity, but we find that
when monitored for longer periods of time, a number of stars shift between
these two variability mechanisms. Further, we show that the intrinsic timescale
of disk/accretion variability in young stars is longer than that of
dust-extinction variability. We confirm that variability amplitude is
statistically correlated with evolutionary class in all bands and colors. Our
investigations of these 1203 variables have revealed 73 periodic AA Tau type
variables, many large-amplitude and long-period (P > 15 day) YSOs, including
three stars showing widely-spaced periodic brightening events consistent with
circumbinary disk activity, and four new eclipsing binaries. These phenomena
and others indicate the activity of long-term disk/accretion variability
processes taking place in young stars. We have made the light curves and
associated data for these 1203 variables available online.Comment: Corrected typo in author nam
Direct analysis of liquid samples by desorption electrospray ionization-mass spectrometry (DESI-MS)
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