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Sample records for boks jhannes sigurjnsson

  1. BOK-Printed Electronics

    NASA Technical Reports Server (NTRS)

    Ghaffarian, Reza

    2013-01-01

    The use of printed electronics technologies (PETs), 2D or 3D printing approaches either by conventional electronic fabrication or by rapid graphic printing of organic or nonorganic electronic devices on various small or large rigid or flexible substrates, is projected to grow exponentially in commercial industry. This has provided an opportunity to determine whether or not PETs could be applicable for low volume and high-reliability applications. This report presents a summary of literature surveyed and provides a body of knowledge (BOK) gathered on the current status of organic and printed electronics technologies. It reviews three key industry roadmaps- on this subject-OE-A, ITRS, and iNEMI-each with a different name identification for this emerging technology. This followed by a brief review of the status of the industry on standard development for this technology, including IEEE and IPC specifications. The report concludes with key technologies and applications and provides a technology hierarchy similar to those of conventional microelectronics for electronics packaging. Understanding key technology roadmaps, parameters, and applications is important when judicially selecting and narrowing the follow-up of new and emerging applicable technologies for evaluation, as well as the low risk insertion of organic, large area, and printed electronics.

  2. Consequences of the combined loss of BOK and BAK or BOK and BAX

    PubMed Central

    Ke, F; Bouillet, P; Kaufmann, T; Strasser, A; Kerr, J; Voss, A K

    2013-01-01

    The multi-BCL-2 homology domain pro-apoptotic BCL-2 family members BAK and BAX have critical roles in apoptosis. They are essential for mitochondrial outer-membrane permeabilization, leading to the release of apoptogenic factors such as cytochrome-c, which promote activation of the caspase cascade and cellular demolition. The BOK protein has extensive amino-acid sequence similarity to BAK and BAX and is expressed in diverse cell types, particularly those of the female reproductive tissues. The BOK-deficient mice have no readily discernible abnormalities, and its function therefore remains unresolved. We hypothesized that BOK may exert functions that overlap with those of BAK and/or BAX and examined this by generating Bok−/−Bak−/− and Bok−/−Bax−/− mice. Combined loss of BOK and BAK did not elicit any noticeable defects, although it remains possible that BOK and BAK have critical roles in developmental cell death that overlap with those of BAX. In most tissues examined, loss of BOK did not exacerbate the abnormalities caused by loss of BAX, such as defects in spermatogenesis or the increase in neuronal populations in the brain and retina. Notably, however, old Bok−/−Bax−/− females had abnormally increased numbers of oocytes from different stages of development, indicating that BOK may have a pro-apoptotic function overlapping with that of BAX in age-related follicular atresia. PMID:23744350

  3. Magnetic Field Maps of Quiescent BOK Globules

    NASA Astrophysics Data System (ADS)

    Kane, Brian D.; Clemens, Dan P.

    1994-12-01

    We present magnetic field maps of 12 starless Bok Globules. Maps were constructed from polarimetric V-band images taken with a computer-controlled CCD camera with a fast shutter and a bidirectional charge-shifting capability. The linear polarization of stars in the globule field has been determined by repeated use of imaging through a polaroid filter, shifting the charge up by many times the stellar PSF, reimaging through an orthogonal polaroid filter, then shifting the charge back down to its starting point. Between one and five CCD fields-of-view were necessary to map each globule, and up to 50 stars in each FOV had detectable polarizations. This globule sample exhibits a variety of magnetic field patterns, including uniform fields with dispersion less than 10(deg) , overlapping fields with two distinct directions, and cometary extensions.

  4. Intracellular localization of the BCL-2 family member BOK and functional implications

    PubMed Central

    Echeverry, N; Bachmann, D; Ke, F; Strasser, A; Simon, H U; Kaufmann, T

    2013-01-01

    The pro-apoptotic BCL-2 family member BOK is widely expressed and resembles the multi-BH domain proteins BAX and BAK based on its amino acid sequence. The genomic region encoding BOK was reported to be frequently deleted in human cancer and it has therefore been hypothesized that BOK functions as a tumor suppressor. However, little is known about the molecular functions of BOK. We show that enforced expression of BOK activates the intrinsic (mitochondrial) apoptotic pathway in BAX/BAK-proficient cells but fails to kill cells lacking both BAX and BAK or sensitize them to cytotoxic insults. Interestingly, major portions of endogenous BOK are localized to and partially inserted into the membranes of the Golgi apparatus as well as the endoplasmic reticulum (ER) and associated membranes. The C-terminal transmembrane domain of BOK thereby constitutes a ‘tail-anchor' specific for targeting to the Golgi and ER. Overexpression of full-length BOK causes early fragmentation of ER and Golgi compartments. A role for BOK on the Golgi apparatus and the ER is supported by an abnormal response of Bok-deficient cells to the Golgi/ER stressor brefeldin A. Based on these results, we propose that major functions of BOK are exerted at the Golgi and ER membranes and that BOK induces apoptosis in a manner dependent on BAX and BAK. PMID:23429263

  5. Structure and dynamics of the Bok globule B335

    NASA Technical Reports Server (NTRS)

    Frerking, M. A.; Langer, W. D.; Wilson, R. W.

    1985-01-01

    CO maps of the Bok globule B335 are presented and used to derive its density profile, mass distribution, and rotational velocity structure. It is found that the cloud is in nearly hydrostatic equilibrium with a density profile that varies roughly as r to the -1 in the core and r to the -3 in the envelope. The observed rotation is unimportant in the force balance at the present stage of evolution.

  6. ISO Observations of Starless Bok Globules: Usually No Embedded Stars

    NASA Technical Reports Server (NTRS)

    Clemens, D.; Byrne, A.; Yun, J.; Kane, B.

    1996-01-01

    We have used ISOCAM to search the cores of a sample of small Bok globules previously classified to be mostly starless based on analysis of IRAS data. The ISO observations at 6.75microns (LW2 filter) and 14.5microns (LW3 filter) were sufficiently deep to enable detection of any low-mass hydrogen burning star or young stellar object (YSO) embedded in these globules. Of the 20 Bok globules observed by ISOCAM to date, we have reduced the data for 14. Of these, 13 show no evidence for faint red (S(sub v)(LW3) greater than S(sub v)(LW2)) stars missed by IRAS. One (CB68) does show the first mid-infrared detection of the very cool IRAS source toward this cloud, and may be a Class I or 0 YSO. We conclude, based on these new ISO observations, that Bok globules which have no IRAS sources are in general bona fide starless molecular clouds.

  7. Improving Students' Familiarity with the Family and Consumer Sciences Body of Knowledge (FCS-BOK)

    ERIC Educational Resources Information Center

    Walker, Jane; Williams-Wheeler, Meeshay; Lee, Sung-Jin

    2015-01-01

    Because the family and consumer sciences body of knowledge (FCS-BOK) is the framework for the profession, students' familiarity with the FCS-BOK has implications for the profession. Using pre- (N = 78) and posttest (N = 43) data from students enrolled in an "Introduction to Family and Consumer Sciences" (FCS 160) undergraduate student…

  8. Assessing Historically Black College and University (HBCU) Students' Familiarity with the FCS-BOK

    ERIC Educational Resources Information Center

    Lee, Sung-Jin; Williams-Wheeler, Meeshay; Walker, Jane

    2015-01-01

    University faculty who are teaching courses in family and consumer sciences (FCS) have sought to integrate the body of knowledge (BOK) in their curricula. This article reports on a study assessing the familiarity of Historically Black College and University (HBCU) students with the FCS-BOK by their major (specialized area) and classification…

  9. Magnetic field dispersion in the neighbourhood of Bok Globules

    NASA Astrophysics Data System (ADS)

    Rodrigues, C. V.; Magalhães, V. de S.; Vilas-Boas, J. W.; Racca, G.; Pereyra, A.

    2014-08-01

    We performed an observational study of the relation between the interstellar magnetic field alignment and star formation in twenty (20) sky regions containing Bok Globules. The presence of young stellar objects in the globules is verified by a search of infrared sources with spectral energy distribution compatible with a pre main-sequence star. The interstellar magnetic field direction is mapped using optical polarimetry. These maps are used to estimate the dispersion of the interstellar magnetic field direction in each region from a Gaussian fit, σ B . In addition to the Gaussian dispersion, we propose a new parameter, η, to measure the magnetic field alignment that does not rely on any function fitting. Statistical tests show that the dispersion of the magnetic field direction is different in star forming globules relative to quiescent globules. Specifically, the less organised magnetic fields occur in regions having young stellar objects.

  10. Magnetic fields around BOK globules: CCD polarimetry of CB 4

    NASA Astrophysics Data System (ADS)

    Kane, Brian D.; Clemens, Dan P.; Leach, Robert W.; Barvainis, Richard

    1995-05-01

    The small Bok globule CB 4 was probed using a CCD imaging polarimeter in order to create a detailed map of the magnetic field associated with this cloud. Stars as faint as 17th mag at V band were measured polarimetrically with uncertainties less than 1%. Sky transmission variations were minimized via a system of synchronous polaroid rotation and bidirectional charge shifting. In all, 80 stars behind the periphery of the globule were accurately analyzed polarimetrically. The large-scale (1-2 pc) magnetic field direction around CB 4 was found to be very uniform (P.A. = 63.3 deg +/- 1.1 deg). Double-Gaussian fitting of the polarization position angle histogram gave a dispersion of 10 deg about the primary field direction. Possible field-line compression was found inward of approximately 0.2 pc from the cloud center. No appreciable twisting of field lines was found. By plotting stellar separations against differences of polarization angles, CB 4 was found to have a magnetic field decorrelation length of approximately 0.1 pc, similar to the size of the visually opaque cire, but much smaller than the size of the bright optical rim or CO half-power contour of approximately 0.5 pc. The magnetic field decorrelation length may be related to a characteristic transient clumping size, or perhaps even to clumps of a more permanent nature.

  11. Molecular profiles and pathogen-induced transcriptional responses of prawn B cell lymphoma-2 related ovarian killer protein (BOK).

    PubMed

    Chaurasia, Mukesh Kumar; Palanisamy, Rajesh; Harikrishnan, Ramasamy; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Arockiaraj, Jesu

    2015-08-01

    In this study, we have reported a molecular characterization of the first B cell lymphoma-2 (BCL-2) related ovarian killer protein (BOK) from freshwater prawn Macrobrachium rosenbergii (Mr). BOK is a novel pro-apoptotic protein of the BCL-2 family that entails in mediating apoptosis to remove cancer cells. A cDNA sequence of MrBOK was identified from the prawn cDNA library and its full length was obtained by internal sequencing. The coding region of MrBOK yields a polypeptide of 291 amino acids. The analysis revealed that MrBOK contains a transmembrane helix at V(261)-L(283) and a putative BCL-2 family domain at V(144)-W(245). MrBOK also possessed four putative BCL-2 homology domains including BH1, BH2, BH3 and weak BH4. The BH3 contains 21 binding sites and among them five residues are highly conserved with the aligned BOK proteins. The homology analysis showed that MrBOK shared maximum similarity with the Caligus rogercresseyi BOK A. The topology of the phylogenetic tree was classified into nine sister groups which includes BOK, BAK, BAX, BAD, BCL-2, BCL-XL, NR13 and MCL members. The BOK protein group further sub-grouped into vertebrate and invertebrate BOK, wherein MrBOK located within insect monophyletic clad of invertebrate BOK. The secondary structural analysis showed that MrBOK contains 11 α-helices (52.2%) which are connected over random coils (47.7%). The 3D structure of MrBOK showed three central helices (α6, α7 and α8) which formed the core of the protein and are flanked on one side by α1, α2 and α3, and on the other side by α4, α5 and α11. MrBOK mRNA is expressed most abundantly (P < 0.05) in ovary compared to other tissues taken for analysis. Hence ovary was selected to study the possible roles of MrBOK mRNA regulation upon bacterial (Aeromonas hydrophila and Vibrio harveyi) and viral [white spot syndrome virus (WSSV) and M. rosenbergii nodovirus] infection. During bacterial and viral infection, the highest MrBOK mRNA transcription was varied

  12. The Arrival of the Bowen-Bok Study on Racial Preferences in College Admissions.

    ERIC Educational Resources Information Center

    Journal of Blacks in Higher Education, 1998

    1998-01-01

    Discusses a study conducted by W. G. Bowen and D. Bok that develops hard empirical evidence about the benefits of using race-sensitive admissions to selective higher education. The database on which this study rests includes more than 80,000 undergraduates from 28 selective institutions. (SLD)

  13. The Bok Award Presented for High School Astronomy Research at the Intel Science Fair

    NASA Astrophysics Data System (ADS)

    Garmany, Catharine D.

    2013-01-01

    The Priscilla and Bart Bok award, presented jointly by the Astronomical Society of the Pacific (ASP) and the American Astronomical Society (AAS) at the annual Intel International Science and Engineering Fair (ISEF), recognizes excellent research in astronomy conducted by high school students. The award is named in honor of two well-known astronomers. Bart Bok was an outstanding research astronomer: much of his research was done with his wife, Priscilla Fairfield Bok. Since 1992, the ASP and the AAS have shared the responsibility of sending three judges to the annual Intel ISEF to select two Bok awardees. Funds for the prizes themselves are derived from an endowment in Bart Bok’s honor held at the ASP. The Intel ISEF is a massive event. In order to become a finalist and attend ISEF, a student must first compete, and win one of the top awards, in both their local and regional science fairs. In recent years, about 1,500 high-school students have attended. About 100 of these students present projects in the category physics: of these, less than 20 are astronomy projects. Winners of the award are invited to attend the winter AAS meeting, and this year both of the 2012 winners are expected to be in attendance. There are also previous winners who are actively in our midst. But there is an unanswered question: why are there so few student projects in astronomy?

  14. Tracing the evolutionary stage of Bok globules: CCS and NH3

    NASA Astrophysics Data System (ADS)

    Marka, C.; Schreyer, K.; Launhardt, R.; Semenov, D. A.; Henning, Th.

    2012-01-01

    Aims: We investigate a previously proposed correlation between the chemical properties and the physical evolutionary stage of isolated low-mass star-forming regions. The NNH3/NCCS abundance ratio has been proposed to be a potentially useful indicator of the evolutionary stage of cloud cores, and we study its applicability for isolated Bok globules. Methods: We searched for CCS(21-10) emission in 42 Bok globules both with and without signs of current star formation. A set of NH3 measurements was compiled from measurements available in the literature and from our own observations. The abundance ratio of both molecules is discussed with respect to the evolutionary stage of the objects and in the context of chemical models. Results: We determine the NNH3/NCCS ratio for 18 Bok globules and find that it is moderately high and roughly similar across all evolutionary stages from starless and prestellar cores towards internally heated cores harboring protostars of Class 0, Class I, or later. We do not find any Bok globules with extremely high CCS abundances analogous to carbon-chain producing regions in dark cloud cores. The observed range of NNH3/NCCS implies that all of the observed Bok globules are in a relatively evolved chemical state. Based on observations obtained with the 100-m telescope of the MPIfR (Max-Planck-Institut für Radioastronomie) at Effelsberg and the 64-m Parkes radio telescope. The Parkes radio telescope is part of the Australia Telescope National Facility which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

  15. THE KEPLER LIGHT CURVE OF THE UNIQUE DA WHITE DWARF BOKS 53856

    SciTech Connect

    Holberg, J. B.; Howell, Steve B. E-mail: howell@noao.edu

    2011-08-15

    The faint (g = 16.9) hot white dwarf BOKS 53856 was observed by the Kepler Mission in short cadence mode during mid-2009. Analysis of these observations reveals a highly stable modulation with a period of 6.1375 hr and a 2.46% half-amplitude. The folded light curve has an unusual shape that is difficult to explain in terms of a binary system containing an unseen companion more luminous than an L0 brown dwarf. Optical spectra of BOKS 53856 show a T{sub eff} = 34,000 K, log g = 8.0 DA white dwarf. There are few, if any, known white dwarfs in this temperature range exhibiting photometric variations similar to those we describe. A magnetic spin-modulated white dwarf model can in principle explain the light curve, an interpretation supported by spectral observations of the H{alpha} line showing evidence of Zeeman splitting.

  16. Far-infrared detection of low-luminosity star formation in the Bok globule B335

    NASA Technical Reports Server (NTRS)

    Davidson, J. A.; Harper, D. A.; Pernic, R.; Jaffe, D. T.; Low, F. J.; Keene, J.; Hildebrand, R. H.; Loewenstein, R. F.

    1983-01-01

    Measurements of far-infrared intensities in the Bok globule B335, made with higher spatial and spectral resolution than two earlier studies, are described. The NASA 3-m Infrared Telescope Facility was used in February 1981 and the Kuiper Airborne Observatory 0.9-m telescope was used in October 1981 and August 1982 for the observations. The far-infrared source in B335 was revealed to be more compact than previously assumed, ruling out the interstellar radiation field as the dominant heat source. The new far-infrared size, luminosity, and temperature derived suggest that these may be the first observations of low-mass star formation embedded deeply within a Bok globule. The far-infrared source does not have a near-infrared or radio continuum counterpart. High angular resolution at submillimeter wavelengths will be critical in further studies of low-mass star formation.

  17. WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

    SciTech Connect

    Zeilstra, Jurrit; Joosten, Sander P.J.; Wensveen, Felix M.; Dessing, Mark C.; Schuetze, Denise M.; Eldering, Eric; Spaargaren, Marcel; Pals, Steven T.

    2011-03-04

    Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causes constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which

  18. Anthocyanin accumulation and transcriptional regulation of anthocyanin biosynthesis in purple bok choy (Brassica rapa var. chinensis).

    PubMed

    Zhang, Yanjie; Chen, Guoping; Dong, Tingting; Pan, Yu; Zhao, Zhiping; Tian, Shibing; Hu, Zongli

    2014-12-24

    Bok choy (Brassica rapa var. chinensis) is an important dietary vegetable cultivated and consumed worldwide for its edible leaves. The purple cultivars rich in health-promoting anthocyanins are usually more eye-catching and valuable. Fifteen kinds of anthocyanins were separated and identified from a purple bok choy cultivar (Zi He) by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms underlying anthocyanin accumulation in bok choy, the expression profiles of anthocyanin biosynthetic and regulatory genes were analyzed in seedlings and leaves of the purple cultivar and the green cultivar (Su Zhouqing). Compared with the other tissues, BrTT8 and most of the anthocyanin biosynthetic genes were significantly up-regulated in the leaves and light-grown seedlings of Zi He. The results that heterologous expression of BrTT8 promotes the transcription of partial anthocyanin biosynthetic genes in regeneration shoots of tomato indicate that BrTT8 plays an important role in the regulation of anthocyanin biosynthesis. PMID:25419600

  19. BOKS 45906: a CV with an Orbital Period of 56.6 Min in the Kepler Field?

    NASA Technical Reports Server (NTRS)

    Ramsay, Gavin; Howell, Steve B.; Wood, Matt A.; Smale, Alan; Barclay, Thomas; Seebode, Sally A.; Gelino, Dawn; Still, Martin; Cannizzo, John K.

    2013-01-01

    BOKS 45906 was found to be a blue source in the Burrell-Optical-Kepler Survey which showed a 3 magnitude outburst lasting approximately 5 days. We present the Kepler light curve of this source which covers nearly 3 years. We find that it is in a faint optical state for approximately half the time and shows a series of outbursts separated by distinct dips in flux. Using data with 1 minute sampling, we find clear evidence that in its low state BOKS 45906 shows a flux variability on a period of 56.5574 plus or minus 0.0014 minutes and a semi-amplitude of approximately 3 percent. Since we can phase all the 1 minute cadence data on a common ephemeris using this period, it is probable that 56.56 minutes is the binary orbital period. Optical spectra of BOKS 45906 show the presence of Balmer lines in emission indicating it is not an AM CVn (pure Helium) binary. Swift data show that it is a weak X-ray source and is weakly detected in the bluest of the UVOT filters. We conclude that BOKS 45906 is a cataclysmic variable with a period shorter than the 'period-bounce' systems and therefore BOKS 45906 could be the first helium-rich cataclysmic variable detected in the Kepler field.

  20. Effects of endocrine disruptor di-n-butyl phthalate on the growth of Bok choy (Brassica rapa subsp. chinensis).

    PubMed

    Liao, Chien-Sen; Yen, Jui-Hung; Wang, Yei-Shung

    2006-12-01

    The effects of the endocrine disrupter, di-n-butyl phthalate (DBP), on the growth of leaf vegetable Bok choy (Brassica rapa subsp. chinensis, white stem Bok choy) were investigated. The results showed that leaves of Bok choy became white in color with the occurrence of chlorosis and necrosis upon treating with 30 mg l(-1) DBP for 42 days. Transmission electron microscopic images revealed that changes in the chloroplast structures accompanied the chlorosis. In addition, a decrease in biomass and chlorophyll, and accumulation of DBP, were found in DBP-treated Bok choy. The growth and morphology of Bok choy showed a significant dose-response relationship upon treatment with DBP in a hydroponic culture medium. The proteome of the leaf tissue was analyzed using two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). Six protein spots were identified in 2-DE that showed reproducible differences in expression between the normal control and the DBP-treated sample. Based on proteome level studies two protein spots increased and were identified as superoxide dismutase (SOD) and peroxidase 21 precursor. These proteins are believed to increase in expression in response to free radical exposure as a detoxification mechanism. The other four protein spots that disappeared on treatment with DBP were identified as heat shock cognate protein 80, protein disulfide isomerase precursor, apocytochrome f precursor, and RNA polymerase beta subunit. The first two play an important role in polypeptide folding, the third is associated with electron transport, and the last has a critical function in DNA transcription. This study indicated that DBP affects the proteome formation as well as the physiology and the morphology of Bok choy during growth. The decrease in those four proteins might be related to the growth and development of a plant. PMID:16824579

  1. Photopolarimetric study of three selected Bok globule (CB56, CB60 and CB69)

    NASA Astrophysics Data System (ADS)

    Chakraborty, Arindwam; Sekhar Das, Himadri; Paul, Dipankar

    2015-08-01

    Bok globules are small isolated dark cloud with a simple structure, when seen through optical wavelengths they looks like a dark patch surrounded by some bright foreground stars. Because of their isolated location and simple structure, they are ideal laboratories, to study in detail the process of low-mass star formation. Aligned dust grains in the interstellar medium (ISM) and the Bok globule polarize the radiation through dichroic extinction. Magnetic fields plays a vital roles in interstellar processes and star formation, and the polarization that results from grain alignment provides the means to study magnetic fields. The relative role played by the magnetic field and the turbulence in cloud formation and evolution in different stages of star formation is quite interesting matter of study. In this paper we will present a combined study of polarization and extinction (Av) of observed background field stars of CB56, CB60 and CB69. We have mapped the local magnetic fields of these globules in V-band by estimating the value of linear polarization of background stars and hence created respective polarization maps. Background field stars are used to probe polarization efficiency (defined as pv/Av) in the quiescent regions of these dark clouds as a function of visual extinction. Our study indicates that the interstellar dust grains alignment decreases with the increase in extinction. This type of study help us in studying the direct interplay between protostellar collapse, fragmentation and magnetic fields.

  2. Hazard map of agricultural products due to typhoons-an example of Bok-choy

    NASA Astrophysics Data System (ADS)

    Lin, Yong-Jun; Ma, Kuo-Chen; Lai, Jihn-Sung; Chang, Tsang-Jung; Tan, Yih-Chi

    2015-04-01

    The torrential rain and strong wind brought by typhoons usually cause huge damages to agricultural products. This study aims at hazard map of agricultural products due to typhoons. The factors affecting the hazard of agricultural products due to typhoons include the duration of flooding, flooding depth, wind speed, and rainfall intensity. High rainfall intensity and high wind speed may knock down the leaves or fruits of the plants. The long-duration of flooding or high flooding depth may chock the plant or rotten the roots. In order to get the information needed for making hazard map due to assumed scenarios, an overland flow simulations is performed for getting the duration of flooding and maximum flooding in the study area. The data of wind speed is obtained from metrological stations. Four levels of hazard are defined due to the characteristic of the chosen agricultural products- Bok-choy (such average height of mature Bok-choy). The final goal of this study is to establish a real-time hazard evaluation system for the specific agricultural products.

  3. C[superscript 2] = BOK: Two Apparel Studies' Capstone Courses Incorporating the Body of Knowledge

    ERIC Educational Resources Information Center

    Smith, Kathleen R.; Apple, Laurie; Souhtward, Leigh

    2014-01-01

    Guided by the five cross-cutting themes of the American Association of Family & Consumer Sciences (AAFCS) Body of Knowledge (BOK) two capstone courses (C[superscript 2]) in Apparel Studies were designed to help prepare students for careers, further study, or both.

  4. Deriving the Age of an Individual WD: SDSS, Bok, USNO, and Bayes

    NASA Astrophysics Data System (ADS)

    von Hippel, Ted; Kilic, Mukremin; Munn, Jeff; Williams, Kurtis; Harris, Hugh; Thorstensen, John; Liebert, Jim; Degennaro, Steven; Jeffery, Elizabeth; Jefferys, Bill; Stein, Nathan; van Dyk, David

    2010-11-01

    We report on ancient white dwarfs found in the proper motion survey we are conducting at the Bok and USNO telescopes. To date we have surveyed approximately 2800 square degrees of sky and identified numerous WDs with Teff <=6000. A subset of these WDs are high velocity objects that most likely belong to the Galactic halo population. Where possible, we are acquiring trigonometric parallaxes to constrain the WD masses. We apply a new Bayesian modeling approach to these WDs that consistently incorporates precursor evolutionary timescales, the initial-final mass relation, WD interior and atmosphere models, and uses the observed magnitudes, distances, etc. to derive the distribution of WD age as a function of uncertainties in the observational parameters.

  5. The Priscilla and Bart Bok Award, presented by the ASP and the AAS at the Intel International Science and Engineering Fair

    NASA Astrophysics Data System (ADS)

    Garmany, K.

    2013-04-01

    The Bok Award is presented to high school students for astronomy research. While there are relatively few astronomy projects at this fair, many of the winners of this award have continued in the field of astronomy.

  6. A Two Micron All Sky Survey Analysis of the Stability of Southern Bok Globules

    NASA Astrophysics Data System (ADS)

    Racca, Germán A.; Vilas-Boas, José W. S.; de la Reza, Ramiro

    2009-10-01

    We used near-infrared Two Micron All Sky Survey data to construct visual extinction maps of a sample of Southern Bok globules utilizing the NICE method. We derived radial extinction profiles of dense cores identified in the globules and analyzed their stability against gravitational collapse with isothermal Bonnor-Ebert spheres. The frequency distribution of the stability parameter (ξmax) of these cores shows that a large number of them are located in stable states, followed by an abrupt decrease of cores in unstable states. This decrease is steeper for globules with associated IRAS point sources than for starless globules. Moreover, globules in stable states have a Bonnor-Ebert temperature of T = 15 ± 6 K, while the group of critical plus unstable globules has a different temperature of T = 10 ± 3 K. Distances were estimated to all the globules studied in this work and the spectral class of the IRAS sources was calculated. No variations were found in the stability parameters of the cores and the spectral class of their associated IRAS sources. On the basis of 13CO J = 1 - 0 molecular line observations, we identified and modeled a blue-asymmetric line profile toward a globule of the sample, obtaining an upper limit infall speed of 0.25 km s-1. Based on a Ph.D. thesis made at Observatório Nacional, Rio de Janeiro, Brazil.

  7. Fitting a Turbulent Cloud Model to CO Observations of Starless Bok Globules

    NASA Astrophysics Data System (ADS)

    Hegmann, M.; Hengel, C.; Röllig, M.; Kegel, W. H.

    We present observations of five starless Bok globules in transitions of 12CO (J=2-1 and {J=3-2}), 13CO (J=2-1), and C18O (J=2-1) which have been obtained at the Heinrich-Hertz-Telescope. For an analysis of the data we use the model of Kegel et al. (see e.g. Piehler & Kegel 1995, A&A 297, 841; Hegmann & Kegel 2000, A&A 359, 405) which describes an isothermal sphere stabilized by turbulent and thermal pressure. This approach deals with the full NLTE radiative transfer problem and accounts for a turbulent velocity field with finite correlation length. By a comparison of observed and calculated line profiles we are able not only to determine the kinetic temperature, hydrogen density and CO coloumn density of the globules, but also to study the properties of the turbulent velocity field, i.e. the variance of its one-point-distribution and its correlation length. We consider our model to be an alternative tool for the evaluation of molecular lines emitted by molecular clouds. The model assumptions are certainly closer to reality than the assumptions behind the standard evaluation models, as for example the LVG model. Our current study shows that that the results obtained from our model can differ significantly from those obtained from a LVG analysis.

  8. Analysis of genetic diversity of Brassica rapa var. chinensis using ISSR markers and development of SCAR marker specific for Fragrant Bok Choy, a product of geographic indication.

    PubMed

    Shen, X L; Zhang, Y M; Xue, J Y; Li, M M; Lin, Y B; Sun, X Q; Hang, Y Y

    2016-01-01

    Non-heading Chinese cabbage [Brassica rapa var. chinensis (Linnaeus) Kitamura] is a popular vegetable and is also used as a medicinal plant in traditional Chinese medicine. Fragrant Bok Choy is a unique accession of non-heading Chinese cabbage and a product of geographic indication certified by the Ministry of Agriculture of China, which is noted for its rich aromatic flavor. However, transitional and overlapping morphological traits can make it difficult to distinguish this accession from other non-heading Chinese cabbages. This study aimed to develop a molecular method for efficient identification of Fragrant Bok Choy. Genetic diversity analysis, based on inter-simple sequence repeat molecular markers, was conducted for 11 non-heading Chinese cabbage accessions grown in the Yangtze River Delta region. Genetic similarity coefficients between the 11 accessions ranged from 0.5455 to 0.8961, and the genetic distance ranged from 0.0755 to 0.4475. Cluster analysis divided the 11 accessions into two major groups. The primer ISSR-840 amplified a fragment specific for Fragrant Bok Choy. A pair of specific sequence-characterized amplified region (SCAR) primers based on this fragment amplified a target band in Fragrant Bok Choy individuals, but no band was detected in individuals of other accessions. In conclusion, this study has developed an efficient strategy for authentication of Fragrant Bok Choy. The SCAR marker described here will facilitate the conservation and utilization of this unique non-heading Chinese cabbage germplasm resource. PMID:27173238

  9. Study of magnetic field geometry and extinction in Bok globule CB130

    NASA Astrophysics Data System (ADS)

    Chakraborty, A.; Das, H. S.

    2016-09-01

    We trace the peripheral magnetic field structure of Bok globule CB130 by estimating the linear polarization of its field stars in the R band. The magnetic field orientation sampled by these stars, aligned on average among themselves, and the polarization produced within the cloud has a different direction from that of Galactic plane with an offset of 53°. The offset between minor axis and the mean magnetic field of CB130 is found to be 80°. The estimated strength of the magnetic field in the plane-of-the-sky is ˜116±19 μG. We constructed the visual extinction map using the Near Infrared Color Excess (NICE) method to see the dust distribution around CB130. Contours of Herschel (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) SPIRE 500 μm dust continuum emission map of this cloud is over-plotted on the visual extinction map, which shows that the regions having higher optical extinction correspond to higher densities of dust. Three distinct high dust density cores (named as C1, C2, and C3) are identified in the extinction map. It is observed that the cores C1 and C3 are located close to two previously known cores CB130-1 and CB130-2, respectively. Estimates of visual extinction of some moderately obscured stars of CB130 are made utilizing near-infrared photometry. It is observed that there is a feeble dependence of polarization on extinction, and the polarization efficiency (defined as p/AV) of the dust grains decreases with the increase in extinction.

  10. Relationships between soil properties and toxicity of copper and nickel to bok choy and tomato in Chinese soils.

    PubMed

    Li, Bo; Zhang, Hongtao; Ma, Yibing; McLaughlin, Mike J

    2013-10-01

    The toxicity of copper (Cu) and nickel (Ni) to bok choy and tomato shoot growth was investigated in a wide range of Chinese soils with and without leaching with artificial rainwater. The results showed that the variations of Ni toxicity induced by soil properties were wider than those of Cu toxicity to both tomato and bok choy plant growth. Leaching generally decreased the toxicity of Cu and Ni added to soils, which also depended on soils, metals, and test plant species. Soil factors controlling metal phytotoxicity were found to be soil pH and soil organic carbon content for Cu, and soil pH for Ni. It was also found that soil pH had stronger effects on Ni toxicity than on Cu toxicity. Predictive toxicity models based on these soil factors were developed. These toxicity models for Cu and Ni toxicity to tomato plant growth were validated using an independent data set for European soils. These models could be applied to predict the Cu and Ni phytotoxicity in not only Chinese soils but also European soils. PMID:23787779

  11. Polarimetría multicolor en dirección a un glóbulo de Bok

    NASA Astrophysics Data System (ADS)

    Rizzo, J. R.; Morras, R.; Arnal, E. M.

    Presentamos resultados de observaciones polarimétricas UBVRI en 65 estrellas muy débiles localizadas en el campo de un Glóbulo de Bok carente de anterior análisis observacional. Los resultados muestran un alto y uniforme grado de polarización --sobre todo en las bandas V, R e I-- en casi todas las estrellas de la muestra, así como una alineación del campo magnético proyectado en torno a la nube similar al del campo magnético general. Adicionalmente, estudiamos la posible conexión con la emisión en el infrarrojo a través de las observaciones del satélite IRAS.

  12. LOOKING INTO THE HEARTS OF BOK GLOBULES: MILLIMETER AND SUBMILLIMETER CONTINUUM IMAGES OF ISOLATED STAR-FORMING CORES

    SciTech Connect

    Launhardt, R.; Henning, Th.; Khanzadyan, T.; Schmalzl, M.; Wolf, S.; Nutter, D.; Ward-Thompson, D.; Bourke, T. L.; Zylka, R.

    2010-05-15

    We present the results of a comprehensive infrared, submillimeter, and millimeter continuum emission study of isolated low-mass star-forming cores in 32 Bok globules, with the aim to investigate the process of star formation in these regions. The submillimeter and millimeter dust continuum emission maps together with the spectral energy distributions are used to model and derive the physical properties of the star-forming cores, such as luminosities, sizes, masses, densities, etc. Comparisons with ground-based near-infrared and space-based mid- and far-infrared images from Spitzer are used to reveal the stellar content of the Bok globules, association of embedded young stellar objects (YSOs) with the submillimeter dust cores, and the evolutionary stages of the individual sources. Submillimeter dust continuum emission was detected in 26 out of the 32 globule cores observed. For 18 globules with detected (sub)millimeter cores, we derive evolutionary stages and physical parameters of the embedded sources. We identify nine starless cores, most of which are presumably prestellar, nine Class 0 protostars, and twelve Class I YSOs. Specific source properties like bolometric temperature, core size, and central densities are discussed as a function of evolutionary stage. We find that at least two thirds (16 out of 24) of the star-forming globules studied here show evidence of forming multiple stars on scales between 1000 and 50,000 AU. However, we also find that most of these small prototstar and star groups are comprised of sources with different evolutionary stages, suggesting a picture of slow and sequential star formation in isolated globules.

  13. Spacewatch Astrometry of Asteroids and Comets with the Bok 2.3-m and Mayall 4-m Telescopes.

    NASA Astrophysics Data System (ADS)

    Scotti, James V.; McMillan, Robert S.; Larsen, Jeffrey A.

    2014-11-01

    We use the Bok 2.3-m and Mayall 4-m telescopes on Kitt Peak to improve knowledge of the orbits and magnitudes of high priority classes of Near Earth Objects (NEOs) and other small bodies in need of recovery that cannot be reached with the Spacewatch 0.9-m and 1.8-m telescopes. Targets include NEOs with potential close encounters with Earth (Virtual Impactors; VIs), future targets of radar, NEOs previously detected by NEOWISE with orbits or albedos suggesting potential for cometary activity, potential destinations for spacecraft, returning NEOs with hard-won albedos and diameters determined by NEOWISE, and faint Potentially Hazardous Asteroids (PHAs). Notable targets successfully recovered include the Earth Trojan 2010 TK7 and the faint almost-lost VI 2011 BY24 discovered by NEOWISE. Between 2010 June 6 and 2014 July 23 the MPC accepted 1316 lines of astrometry by us with these telescopes on 207 different NEOs including 84 PHAs. We made 343 observations of PHAs with V>=22. Our average arc extension on large PHAs (with H<=17.75) is 184 days, which is 2x longer than the next most effective observing station. Recently with all four telescopes Spacewatch has made 39% of all the observations of PHAs that were fainter than V=22 at the time of measurement. This count is twice that of the next most productive station in that measure. The faintest V magnitude we have observed so far is 24.4 and the smallest solar elongation angle at which we have observed is 46 degrees. Our work with the Mayall and Bok telescopes has been determined by the Minor Planet Center (MPC) to provide "dramatic improvement" to NEO orbits (T. Spahr, 2014 private communication). Support of Spacewatch was/is from JPL subcontract 100319 (2010-2011), NASA/NEOO grants NNG06GJ42G, NNX11AB52G, NNX12AG11G, NNX13AP99G, NNX14AL13G, and NNX14AL14G, the Lunar and Planetary Laboratory, the Brinson Foundation of Chicago, IL, the estates of R. S. Vail and R. L. Waland, and other private donors. We are also indebted

  14. Determination of the physical parameters of Bok-globules by means of a stochastical radiative transfer method

    NASA Astrophysics Data System (ADS)

    Hengel, C.; Hegmann, M.; Röllig, M.; Kegel, W. H.

    During the last years, one of the key projects of the Astrophysics group at the University of Frankfurt was the theoretical examination of the influence of turbulence and density fluctuations on the formation of interstellar molecular lines, especially CO lines (Albrecht & Kegel 1987, Kegel et al. 1993, Piehler & Kegel 1995, Hegmann 1999). Based on an approach by G. Traving and collaborators (cf. Gail et al. 1974), a numerical code has been developed to deal with the NLTE problem in an isothermal spherical cloud being stabelized by turbulent and thermal pressure, considering the turbulent velocity field to be stochastic. Our model has been primarily constructed to achieve theoretical insight in the fundamental mechanisms of line formation under more realistic conditions. In view of the stage of development, the model has actually reached, we seriously think of it as an alternative tool for the evaluation of molecular lines emitted by molecular clouds, especially as the model assumptions are certainly closer to reality than the assumptions behind the standard evaluation methods such as e. g. LVG analysis. The objects the physics of which we believe to be closest to our model assumptions are starless Bok globules. We thus have performed observations at the HHT, where we have collected data of five Bok globules in the CO(2-1), CO(3-2), 13CO(2-1) and C18O(2-1) lines. In my contribution I will adress the question, if and how the physical parameters derived by our analysis of the observational data (central H2 density, temperature, correlation length of the turbulent velocity field, and mean square turbulent velocity) differ from the results of an LVG analysis (they do!) and what these findings imply from a physical point of view as well as from a critical viewpoint on the practice of data evaluation. I will talk about problems of our model at its current stage and possible consequences for an improvement of the model, and I will finally give an outlook, how, with

  15. Voices in American Education: Conversations with Patricia Biehl, Derek Bok, Daniel Callahan, Robert Coles, Edwin Dorn, Georgie Anne Geyer, Henry Giroux, Ralph Ketcham, Christopher Lasch, Elizabeth Minnich, Frank Newman, Robert Payton, Douglas Sloan, and Manfred Stanley.

    ERIC Educational Resources Information Center

    Murchland, Bernard

    Interviews expressing a variety of viewpoints on the present and future status of education on a national and global scale are offered by 14 major educators and public figures. The theme of educational reform frames each interview. Patricia Biehl reflects on the diminishing effectiveness of secondary education. Derek Bok favors the teaching of…

  16. Body of Knowledge (BOK) for Leadless Quad Flat No-Lead/bottom Termination Components (QFN/BTC) Package Trends and Reliability

    NASA Technical Reports Server (NTRS)

    Ghaffarian, Reza

    2014-01-01

    Bottom terminated components and quad flat no-lead (BTC/QFN) packages have been extensively used by commercial industry for more than a decade. Cost and performance advantages and the closeness of the packages to the boards make them especially unique for radio frequency (RF) applications. A number of high-reliability parts are now available in this style of package configuration. This report presents a summary of literature surveyed and provides a body of knowledge (BOK) gathered on the status of BTC/QFN and their advanced versions of multi-row QFN (MRQFN) packaging technologies. The report provides a comprehensive review of packaging trends and specifications on design, assembly, and reliability. Emphasis is placed on assembly reliability and associated key design and process parameters because they show lower life than standard leaded package assembly under thermal cycling exposures. Inspection of hidden solder joints for assuring quality is challenging and is similar to ball grid arrays (BGAs). Understanding the key BTC/QFN technology trends, applications, processing parameters, workmanship defects, and reliability behavior is important when judicially selecting and narrowing the follow-on packages for evaluation and testing, as well as for the low risk insertion in high-reliability applications.

  17. Body of Knowledge (BOK) for Leadless Quad Flat No-Lead/Bottom Termination Components (QFN/BTC) Package Trends and Reliability

    NASA Technical Reports Server (NTRS)

    Ghaffarian, Reza

    2014-01-01

    Bottom terminated components and quad flat no-lead (BTC/QFN) packages have been extensively used by commercial industry for more than a decade. Cost and performance advantages and the closeness of the packages to the boards make them especially unique for radio frequency (RF) applications. A number of high-reliability parts are now available in this style of package configuration. This report presents a summary of literature surveyed and provides a body of knowledge (BOK) gathered on the status of BTC/QFN and their advanced versions of multi-row QFN (MRQFN) packaging technologies. The report provides a comprehensive review of packaging trends and specifications on design, assembly, and reliability. Emphasis is placed on assembly reliability and associated key design and process parameters because they show lower life than standard leaded package assembly under thermal cycling exposures. Inspection of hidden solder joints for assuring quality is challenging and is similar to ball grid arrays (BGAs). Understanding the key BTC/QFN technology trends, applications, processing parameters, workmanship defects, and reliability behavior is important when judicially selecting and narrowing the follow-on packages for evaluation and testing, as well as for the low risk insertion in high-reliability applications.

  18. BOK-Underfill Optimization for FPGA Package/Assembly

    NASA Technical Reports Server (NTRS)

    Ghaffarian, Reza

    2011-01-01

    Commercial-off-the-shelf area array package technologies in high-reliability versions are being considered for NASA electronic systems. These packages are prone to early failure due to the severe mechanical shock and vibration of launch, as well as other less severe conditions, such as mechanical loading during descent, rough terrain mobility, handling, and ground tests. As the density of these packages increases and the size of ball interconnections decrease, susceptibility to mechanical loading and cycling fatigue grows. This report presents a summary of the body of knowledge developed for the evaluation of area array packages and is based on surveys of literature from industry and academia. For high-reliability applications, the limited data that exists will be presented. Most data from industry deals with mechanical fatigue caused by four-point bend tests, as well as from drop tests for hand-held electronics; the most recent data will be presented, along with a brief background of prior literature. Understanding the key design guidelines and failure mechanisms from past tests is critical to developing an approach that will minimize future failures. Additional specific testing enables low-risk insertion of these advanced electronic packages.

  19. Book of Knowledge (BOK) for NASA Electronic Packaging Roadmap

    NASA Technical Reports Server (NTRS)

    Ghaffarian, Reza

    2015-01-01

    The objective of this document is to update the NASA roadmap on packaging technologies (initially released in 2007) and to present the current trends toward further reducing size and increasing functionality. Due to the breadth of work being performed in the area of microelectronics packaging, this report presents only a number of key packaging technologies detailed in three industry roadmaps for conventional microelectronics and a more recently introduced roadmap for organic and printed electronics applications. The topics for each category were down-selected by reviewing the 2012 reports of the International Technology Roadmap for Semiconductor (ITRS), the 2013 roadmap reports of the International Electronics Manufacturing Initiative (iNEMI), the 2013 roadmap of association connecting electronics industry (IPC), the Organic Printed Electronics Association (OE-A). The report also summarizes the results of numerous articles and websites specifically discussing the trends in microelectronics packaging technologies.

  20. Bok Prize Lecture (shared) The Brown Dwarf Radial Velocity Survey

    NASA Astrophysics Data System (ADS)

    Charbonneau, Dave

    2004-03-01

    The swarm of nearby brown dwarfs and very low mass stars is an attractive sample for radial velocity monitoring. Such work is best conducted with an echelle spectrograph operating at infrared wavelengths where these objects(i) are most luminous, (ii) have a forest of molecular features, providing an excellent velocity metric, and {iii) are superimposed on the telluric spectrum, which yields the requisite wavelength calibration. I will present first results from such a survey, with a precision sufficient to detect Jupiter-mass planets with orbital periods of less than a year. Should such systems be uncovered, the planets would be amenable to direct study, due to system proximity, and the favorable contrast ratio between the planet and parent object.

  1. Body of Knowledge (BOK) for Copper Wire Bonds

    NASA Technical Reports Server (NTRS)

    Rutkowski, E.; Sampson, M. J.

    2015-01-01

    Copper wire bonds have replaced gold wire bonds in the majority of commercial semiconductor devices for the latest technology nodes. Although economics has been the driving mechanism to lower semiconductor packaging costs for a savings of about 20% by replacing gold wire bonds with copper, copper also has materials property advantages over gold. When compared to gold, copper has approximately: 25% lower electrical resistivity, 30% higher thermal conductivity, 75% higher tensile strength and 45% higher modulus of elasticity. Copper wire bonds on aluminum bond pads are also more mechanically robust over time and elevated temperature due to the slower intermetallic formation rate - approximately 1/100th that of the gold to aluminum intermetallic formation rate. However, there are significant tradeoffs with copper wire bonding - copper has twice the hardness of gold which results in a narrower bonding manufacturing process window and requires that the semiconductor companies design more mechanically rigid bonding pads to prevent cratering to both the bond pad and underlying chip structure. Furthermore, copper is significantly more prone to corrosion issues. The semiconductor packaging industry has responded to this corrosion concern by creating a palladium coated copper bonding wire, which is more corrosion resistant than pure copper bonding wire. Also, the selection of the device molding compound is critical because use of environmentally friendly green compounds can result in internal CTE (Coefficient of Thermal Expansion) mismatches with the copper wire bonds that can eventually lead to device failures during thermal cycling. Despite the difficult problems associated with the changeover to copper bonding wire, there are billions of copper wire bonded devices delivered annually to customers. It is noteworthy that Texas Instruments announced in October of 2014 that they are shipping microcircuits containing copper wire bonds for safety critical automotive applications. An evaluation of copper wire bond technology for applicability to spaceflight hardware may be warranted along with concurrently compiling a comprehensive understanding of the failure mechanisms involved with copper wire bonded semiconductor devices.

  2. NASA 2009 Body of Knowledge (BoK) Through-Slicon Via Technology

    NASA Technical Reports Server (NTRS)

    Gerke, David

    2009-01-01

    Through-silicon via (TSV) is the latest in a progression of technologies for stacking silicon devices in three dimensions (3D). Driven by the need for improved performance, methods to use short vertical interconnects to replace the long interconnects found in 2D structures have been developed. The industry is moving past the feasibility (research and development [R and D]) phase for TSV technology into the commercialization phase where economic realities will determine which technologies are adopted. Low-cost fine via hole formation and highly reliable via filling technologies have been demonstrated; process equipment and materials are available. Even though design, thermal, and test issues remain, much progress has been made.

  3. THE BURRELL-OPTICAL-KEPLER-SURVEY (BOKS). I. SURVEY DESCRIPTION AND INITIAL RESULTS

    SciTech Connect

    Feldmeier, John J.; Kutsko, Rebecca M.; Howell, Steve B.; Sherry, William; Von Braun, Kaspar; Ciardi, David R.; Everett, Mark E.; Paul Harding; Mihos, J. Christopher; Rudick, Craig S.; Lee, Ting-Hui; Van Belle, Gerard T.

    2011-07-15

    We present the initial results of a 40 night contiguous ground-based campaign of time series photometric observations of a 1.39 deg{sup 2} field located within the NASA Kepler Mission field of view. The goal of this pre-launch survey was to search for transiting extrasolar planets and to provide independent variability information of stellar sources. We have gathered a data set containing light curves of 54,687 stars from which we have created a statistical sub-sample of 13,786 stars between 14 < r < 18.5 and have statistically examined each light curve to test for variability. We present a summary of our preliminary photometric findings including the overall level and content of stellar variability in this portion of the Kepler field and give some examples of unusual variable stars found within. We present a preliminary catalog of 2,457 candidate variable stars, of which 776 show signs of periodicity. We also present three potential exoplanet candidates, all of which should be observable by the Kepler mission.

  4. Disciplinary Categories, Majors, and Undergraduate Academic Experiences: Rethinking Bok's "Underachieving Colleges" Thesis

    ERIC Educational Resources Information Center

    Brint, Steven; Cantwell, Allison M.; Saxena, Preeta

    2012-01-01

    Using data from the 2008 University of California Undergraduate Experience Survey, we show that study time and academic conscientiousness were lower among students in humanities and social science majors than among students in science and engineering majors. Analytical and critical thinking experiences were no more evident among humanities and…

  5. Observations of formaldehyde absorption in the region of NGC 2264 and other Bok globules

    NASA Technical Reports Server (NTRS)

    Rickard, L. J.; Palmer, P.; Buhl, D.; Zuckerman, B.

    1977-01-01

    The paper reports observations of 6-cm H2CO absorption over an extended region surrounding the globule in NGC 2264 and toward the globules B68, B72, B133, B134, B227, B238, and B335. The lines observed from the globules are similar to those seen in more extended dark clouds. It is inferred that physical conditions are similar in the two types of region. Negative results for several other globules are reported.

  6. Bok Prize Lecture (shared) Towards a Physical Characterization of Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Seager, Sara

    2004-03-01

    We have entered a new era in planetary astrophysics with well over 100 giant planets now known to orbit nearby sun-like stars. Recent theoretical and observational advances have given us new constraints on the physical characteristics of extrasolar planets, while ongoing and proposed observing programs and space missions hold great promise for the future of extrasolar planet science. I will discuss the emerging understanding of the extrasolar transiting planet HD209458b, tying together several recent observational constraints as well as key upcoming measurements.I will also briefly review scientific highlights and prospects for the future detection and study of Earth-like extrasolar planets.

  7. Improved Flat-Fielding for Crowded Field Imaging Polarimetry: The Star Forming BOK Globule B335

    NASA Astrophysics Data System (ADS)

    Wright, J.; Ilardi, P.; Clemens, D.

    1996-05-01

    In order to achieve a qualitative improvement in descriptions of the magnetic fields associated with small, dense molecular clouds, traced via background starlight polarization, a CCD-based imaging polarimeter was built and operated. This instrument simultaneously measured the linear polarizations of 25 - 50 stars per 5 arcminute CCD frame (Clemens and Leach 1987, Optical Engineering, 29, 923). The instrument consisted of a rotating polaroid in front of a quarter-wave plate, broadband V filter, and a TI 800 x 800 pixel CCD. The observing mode involved polarization chopping and dual direction CCD charge shifting, resulting in images which contained two stellar objects for each star. However, decoupling of the flat-field response of the CCD from the shifted-and-added images is not trivial. One solution was to ignore the flat-field step and proceed to photometric and then polarimetric analysis of the star light, as was performed by Kane in his dissertation (1995, Boston University). Revisiting the flat-fielding problem, we have developed a new approach which borrows from techniques employed in ground-based infrared astronomy. In this method, we analyze the shape of the stellar background (sky) imaged onto the CCD, via comparison with dome flats, to develop a detailed sky model. Subtraction of this sky model from the raw images leaves sky corrected stellar images. Stellar pair matching and classification is used to extract the individual stellar PSFs for direct flat field correction before performing photometry. This detailed analysis results in lower random and systematic errors than our previous method. In this poster, we present the polarimetric map deduced from the light of stars behind the periphery of the star forming globule B335, and compare the polarimetric limits obtained using our two methods.

  8. Academic Disciplines and the Undergraduate Experience: Rethinking Bok's "Underachieving Colleges" Thesis. SERU Project and Consortium Research Paper. Research & Occasional Paper Series: CSHE.6.11

    ERIC Educational Resources Information Center

    Brint, Steven; Cantwell, Allison M.

    2011-01-01

    Using data from the 2008 University of California Undergraduate Experience Survey, we show that study time and academic conscientiousness were lower among students in humanities and social science majors than among students in science and engineering majors. Analytical and critical thinking experiences were no more evident among humanities and…

  9. The FCS Body of Knowledge: Shaping the Next 100 Years

    ERIC Educational Resources Information Center

    Journal of Family and Consumer Sciences, 2010

    2010-01-01

    This article shares the Body of Knowledge (BOK) as articulated in the new "Accreditation Documents for Undergraduate Programs in Family and Consumer Sciences" (2010). The purpose of sharing the BOK is to enhance awareness of the current knowledge base of family and consumer sciences (FCS), whether for new or lifelong AAFCS members, those exploring…

  10. VizieR Online Data Catalog: Isolated starless cores dust temperature (Lippok+, 2016)

    NASA Astrophysics Data System (ADS)

    Lippok, N.; Launhardt, R.; Henning, T.; Beuther, H.; Balog, Z.; Kainulainen, J.; Krause, O.; Linz, H.; Nielbock, M.; Ragan, S. E.; Robitaille, T. P.; Sadavoy, S. I.; Schmiedeke, A.

    2016-06-01

    Dust temperature maps for 6 Bok globules with starless cores are presented. The following Bok globules have been observed: CB4, CB17, CB26, CB27, B68, CB244 The midplane dust temperature [K] maps are provides as fits files. (2 data files).

  11. Promoting Strong Community Alliances with Public Schools

    ERIC Educational Resources Information Center

    Swafford, Melinda; Ramsey, Elizabeth; Self-Mullens, Lizabeth

    2015-01-01

    Family and consumer sciences (FCS) professionals utilize the body of knowledge (BOK) as they support individuals, families, and communities. The BOK uses an ecological perspective, with emphasis on individual and family well-being. This holistic approach identifies interdependence of the environmental layers that must be considered when analyzing…

  12. Phenolic Component Profiles of Mustard Greens, Yu Choy, and 15 Other Brassica Vegetables

    PubMed Central

    Lin, Long-Ze; Harnly, James M

    2013-01-01

    A liquid chromatography–mass spectrometry (LC-MS) profiling method was used to characterize the phenolic components of 17 leafy vegetables from Brassica species other than Brassica oleracea. The vegetables studied were mustard green, baby mustard green, gai choy, baby gai choy, yu choy, yu choy tip, bok choy, bok choy tip, baby bok choy, bok choy sum, Taiwan bok choy, Shanghai bok choy, baby Shanghai bok choy, rapini broccoli, turnip green, napa, and baby napa. This work led to the tentative identification of 71 phenolic compounds consisting of kaempferol 3-O-diglucoside-7-O-glucoside derivatives, isorhamnetin 3-O-glucoside-7-O-glucoside hydroxycinnamoyl gentiobioses, hydroxycinnamoylmalic acids, and hydroxycinnamoylquinic acids. Ten of the compounds, 3-O-diacyltriglucoside-7-O-glucosides of kaempferol and quercetin, had not been previously reported. The phenolic component profiles of these vegetables were significantly different than those of the leafy vegetables from B. oleracea. This is the first comparative study of these leafy vegetables. Ten of the vegetables had never been previously studied by LC-MS. PMID:20465307

  13. Phenolic component profiles of mustard greens, yu choy, and 15 other brassica vegetables.

    PubMed

    Lin, Long-Ze; Harnly, James M

    2010-06-01

    A liquid chromatography-mass spectrometry (LC-MS) profiling method was used to characterize the phenolic components of 17 leafy vegetables from Brassica species other than Brassica oleracea. The vegetables studied were mustard green, baby mustard green, gai choy, baby gai choy, yu choy, yu choy tip, bok choy, bok choy tip, baby bok choy, bok choy sum, Taiwan bok choy, Shanghai bok choy, baby Shanghai bok choy, rapini broccoli, turnip green, napa, and baby napa. This work led to the tentative identification of 71 phenolic compounds consisting of kaempferol 3-O-diglucoside-7-O-glucoside derivatives, isorhamnetin 3-O-glucoside-7-O-glucoside hydroxycinnamoyl gentiobioses, hydroxycinnamoylmalic acids, and hydroxycinnamoylquinic acids. Ten of the compounds, 3-O-diacyltriglucoside-7-O-glucosides of kaempferol and quercetin, had not been previously reported. The phenolic component profiles of these vegetables were significantly different than those of the leafy vegetables from B. oleracea. This is the first comparative study of these leafy vegetables. Ten of the vegetables had never been previously studied by LC-MS. PMID:20465307

  14. Nutrition Guide for Toddlers

    MedlinePlus

    ... cooked dry beans, or 1 egg. continue Milk Matters An important part of a toddler's diet, milk ... fortified breads and cereals, cooked dried beans, and dark green vegetables like broccoli, bok choy, and kale. ...

  15. 76 FR 51027 - Pesticide Products; Receipt of Applications to Register New Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-17

    ... so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. 2...): Amur river grape, broccoli raab, cantaloupe, Chinese cabbage (bok choy), citron melon, collards,...

  16. Political Education in/as the Practice of Freedom: A Paradoxical Defence from the Perspective of Michael Oakeshott

    ERIC Educational Resources Information Center

    Engel, Stephen M.

    2007-01-01

    Creating education systems that promote democratic sustainability has been the concern of political thinkers as diverse as J. S. Mill, Dewey, Benjamin Barber and Derek Bok. The classic dichotomisation of democratic theory between deliberative democrats and Schumpeterian democrats suggests that education in the service of democracy can be…

  17. From Study Abroad to Global Studies: Reconstructing International Education for a Globalized World

    ERIC Educational Resources Information Center

    Long, Theodore E.

    2013-01-01

    Study abroad has become a substantial enterprise as educators embraced the idea that learning about other cultures is a critical component of becoming an educated person, succeeding at work, and serving as an effective citizen (Bok, 2006). Studies now show that study abroad is positively related to student persistence and success, and liberal…

  18. A Model for Developing Improvements to Critical Thinking Skills across the Community College Curriculum

    ERIC Educational Resources Information Center

    McGarrity, DeShawn N.

    2013-01-01

    Society is faced with more complex problems than in the past because of rapid advancements in technology. These complex problems require multi-dimensional problem-solving abilities that are consistent with higher-order thinking skills. Bok (2006) posits that over 90% of U.S. faculty members consider critical thinking skills as essential for…

  19. I've Known Rivers: Reflections on Self-Education and the Cornell Experiment, 1966-1970.

    ERIC Educational Resources Information Center

    McPhail, Irving Pressley

    A graduate of Cornell university's class of 1970 reflects on his experiences as a black undergraduate at Cornell from 1966 to 1970, what affirmative action meant to him and his generation of college students, and the self-education black students experienced at Cornell at that time. William Bowen and Derek Bok recently published "The Shape of the…

  20. Spectroscopic Classification of MASTER OT J152333.04+092125.6 as a post-maximum Type Ia Supernova

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Charles; Andrews, Jennifer; Milne, Peter; Smith, Nathan

    2016-04-01

    The AZTEC (Arizona Transient Exploration and Characterization) collaboration reports an optical spectrum of MASTER OT J152333.04+092125.6 (ATEL #8903) obtained on UT 2016 Apr. 27.440 with the 2.3m Bok telescope (+ Boller & Chivens spectrograph) on Kitt Peak, Arizona.

  1. Assessing Intercultural Competence

    ERIC Educational Resources Information Center

    Deardorff, Darla K.

    2011-01-01

    In his book "Our Underachieving Colleges," Derek Bok laments the poor job postsecondary institutions are doing in preparing students for the twenty-first century. Other scholars have likewise noted the central responsibility of today's institutions of higher education being to train students to function more effectively in the integrated world…

  2. The "Ladies' Home Journal" between 1890 and 1906: The Influence of Its Crusade To Regulate Food and Drug Products.

    ERIC Educational Resources Information Center

    Harris-Wheeker, Sally A.

    This paper discusses how "The Ladies' Home Journal" was used by its editor, Edward Bok, in his crusade for food and drug regulation in the United States between the years 1890 and 1906, and whether these efforts were influential in bringing about the Pure Food and Drug Act of 1906. The first section describes "The Ladies' Home Journal's" crusade…

  3. Ethnic and Gender Differences in Science Graduation at Selective Colleges with Implications for Admission Policy and College Choice.

    ERIC Educational Resources Information Center

    Smyth, Frederick L.; McArdle, John J.

    Emphasizing graduation rate, W. Bowen and D. Bok (1998) argue that race-sensitive admission at selective colleges enhances the educational attainment of underrepresented minority students, and that the effect increases with college selectivity. Focusing on graduation in science, however, R. Elliott and colleagues (1995) conclude that: (1)…

  4. The Changing Shape of the River: Affirmative Action and Recent Social Science Research

    ERIC Educational Resources Information Center

    Nieli, Russell

    2004-01-01

    In the eyes of much of the academic establishment, William Bowen and Derek Bok's "The Shape of the River" is the definitive defense of affirmative action. Released in 1998, this book, which was also sponsored by the Mellon Foundation, claimed that racial preferences at America's elite universities were crucial to the growth and maintenance of a…

  5. 40 CFR 180.349 - Fenamiphos; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....10 None Brussels sprouts 0.05 12/31/09 Cabbage 0.10 12/31/09 Cherry, sweet 0.25 12/31/09 Cherry, tart... Cabbage, Chinese, bok choy 0.50 12/31/09 Kiwifruit 0.10 12/31/09 Pepper, nonbell 0.60 12/31/09...

  6. Project Produce

    ERIC Educational Resources Information Center

    Wolfinger, Donna M.

    2005-01-01

    The grocery store produce section used to be a familiar but rather dull place. There were bananas next to the oranges next to the limes. Broccoli was next to corn and lettuce. Apples and pears, radishes and onions, eggplants and zucchinis all lay in their appropriate bins. Those days are over. Now, broccoli may be next to bok choy, potatoes beside…

  7. Universities in the Marketplace: The Commercialization of Higher Education

    ERIC Educational Resources Information Center

    Bok, Derek

    2004-01-01

    Is everything in a university for sale if the price is right? In this book, one of America's leading educators cautions that the answer is all too often "yes." Taking the first comprehensive look at the growing commercialization of our academic institutions, Derek Bok probes the efforts on campus to profit financially not only from athletics but…

  8. On the Stability and Evolution of Isolated Molecular Clouds

    NASA Technical Reports Server (NTRS)

    Langer, W.; Nelson, R.

    1998-01-01

    We present the results of three dimensional hydrodynamic models of evolving, isolated, low mass, quiescent clouds and Bok gobules, where the interstellar radiation field plays an important role in the thermal and chemical evolution, and thermal pressure provides dominant support against gravitational collapse.

  9. The Source of the River: The Social Origins of Freshmen at America's Selective Colleges and Universities

    ERIC Educational Resources Information Center

    Massey, Douglas S.; Charles, Camille Z.; Lundy, Garvey F.; Fischer, Mary J.

    2006-01-01

    African Americans and Latinos earn lower grades and drop out of college more often than whites or Asians. Yet thirty years after deliberate minority recruitment efforts began, we still don't know why. In "The Shape of the River," William Bowen and Derek Bok documented the benefits of affirmative action for minority students, their communities, and…

  10. Examining a knowledge domain: Interactive visualization of the Geographic Information Science and Technology Body of Knowledge 1

    NASA Astrophysics Data System (ADS)

    Stowell, Marilyn Ruth

    This research compared the effectiveness and performance of interactive visualizations of the GIS&T Body of Knowledge 1. The visualizations were created using Processing, and display the structure and content of the Body of Knowledge using various spatial layout methods: the Indented List, Tree Graph, treemap and Similarity Graph. The first three methods utilize the existing hierarchical structure of the BoK text, while the fourth method (Similarity Graph) serves as a jumping off point for exploring content-based visualizations of the BoK. The following questions have guided the framework of this research: (1) Which of the spatial layouts is most effective for completing tasks related to the GIS&T; BoK overall? How do they compare to each other in terms of performance? (2) Is one spatial layout significantly more or less effective than others for completing a particular cognitive task? (3) Is the user able to utilize the BoK as a basemap or reference system and make inferences based on BoK scorecard overlays? (4) Which design aspects of the interface assist in carrying out the survey objectives? Which design aspects of the application detract from fulfilling the objectives? To answer these questions, human subjects were recruited to participate in a survey, during which they were assigned a random spatial layout and were asked questions about the BoK based on their interaction with the visualization tool. 75 users were tested, 25 for each spatial layout. Statistical analysis revealed that there were no statistically significant differences between means for overall accuracy when comparing the three visualizations. In looking at individual questions, Tree Graph and Indented List yielded statistically significant higher scores for questions regarding the structure of the Body of Knowledge, as compared to the treemap. There was a significant strong positive correlation between the time taken to complete the survey and the final survey score. This correlation was

  11. Observations of Periodic Comet 2P/Encke: Physical Properties of the Nucleus and First Visual-Wavelength Detection of Its Dust Trail

    NASA Technical Reports Server (NTRS)

    Lowry, Stephen C.; Weissman, Paul R.; Sykes, Mark V.; Reach, William T.

    2003-01-01

    We are conducting an observational program designed to determine the overall distributions of size, shape, rotation period, and surface characteristics of cometary nuclei. Here, we present results from a study of the Jupiter- family comet 2P/Encke based on observations from Steward Observatory's 2.3m Bok Telescope at Kitt Peak. This comet has been observed extensively in the past and was one of the primary flyby targets of the recently failed CONTOUR mission.

  12. Spectroscopy of PSN J19583553+0236163

    NASA Astrophysics Data System (ADS)

    Leonard, D. C.; Moustakas, J.; Swift, B. J.; McCarthy, D.; Bailey, V.; Carrico, E.; Carter, A.; Chui, E.; Douglas, E.; Eggeman, E.; Goldberg, R.; Grant, R.; Hartman, K.; Hellerstein, J.; Hooper, E.; Horlick-Cruz, C.; Hunter, L.; Jiles, T.; Johnson, E. D.; Kumar, K.; Lappe, L.; Lee, J.; Lee, W.; Marsh, F.; Mehta, G.; Miller, P.; Rampalli, R.; Reed, J.; Rice, K.; Saldivar, H.; Salgado-Flores, M.; Schlingman, A.; Schlingman, W. F.; Schlingman, W. M.; Scibelli, S.; Sinclair, K.; Steincamp, I.; Stock, N.; Todd, N.; Vargas, L. L. Aizpuru; Yamanaka, S.; Zachary, E.

    2011-06-01

    As part of the 2011 Advanced Teen Astronomy Camp (http://www.astronomycamp.org), we obtained a low dispersion optical spectrum (range 370-690 nm) of PSN J19583553+0236163 in UGC 11501 with the 2.3m Bok telescope (+ Boller & Chivens spectrograph) at Steward Observatory, on 2011 June 23 UT. Cross-correlation with a library of supernova spectra using the Supernova Identification code (SNID; Blondin and Tonry 2007, Ap.J.

  13. Submillimeter astronomy at the NASA/University of Hawaii 3-meter infrared telescope facility

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Problems encountered in the design of a submillimeter photometer for the infrared telescope facility and some of the solutions already provided are described. Observations of Saturn's rings and the determination of the brightness temperature of Titan, Jupiter, Saturn, Neptune, and Uranus are summarized. Significant findings during solar, galactic, and extragalactic observations include the discovery of low luminosity star formation in the Bok Globule B335 and determination of the far infrared properties of dust in the reflection nebula NGC 7023.

  14. VizieR Online Data Catalog: z>4.5 QSOs with SDSS and WISE. I. Opt. spectra (Wang+, 2016)

    NASA Astrophysics Data System (ADS)

    Wang, F.; Wu, X.-B.; Fan, X.; Yang, J.; Yi, W.; Bian, F.; McGreer, I. D.; Yang, Q.; Ai, Y.; Dong, X.; Zuo, W.; Jiang, L.; Green, R.; Wang, S.; Cai, Z.; Wang, R.; Yue, M.

    2016-05-01

    Optical spectroscopic observations to identify these quasar candidates were carried out using several facilities: the Lijiang 2.4m telescope (LJT) and the Xinglong 2.16m telescope in China; the Kitt Peak 2.3m Bok telescope and the 6.5m MMT telescope in the U.S.; and the 2.3m ANU telescope in Australia. (4 data files).

  15. Comparative persistence of pesticides on selected cultivars of specialty vegetables.

    PubMed

    Ripley, Brian D; Ritcey, Gwen M; Harris, C Ronald; Denommé, Mary Anne; Lissemore, Linda I

    2003-02-26

    The behavior and dissipation of several pesticides on selected cultivars of specialty vegetable crops were compared to determine appropriate preharvest intervals for compliance with maximum residue limits. To reduce application variability, a tank mix of pesticides was applied for each trial. Residues of eight pesticides applied to bok choi, Chinese broccoli, and fuzzy squash were similar for the two leafy vegetables; residues were higher than on squash because of the latter's larger mass-to-surface area ratio. Whereas residues of five of the nine pesticides applied to cabbage, Chinese cabbage, and bok choi did not differ significantly from 3 to 14 days after application, residues of cypermethrin and three fungicides were significantly higher on Chinese cabbage and bok choi. The residue deposits of the pesticides were about 50% lower on Chinese cabbage and 90% lower on cabbage than on bok choi. Dissipation of residues on different cultivars of lettuce and cabbage were compared after application of nine pesticides. With the exception of captan, residues on head lettuce were lower than on the other lettuces on day 1; cultivar differences were not significant for most of the nine applied pesticides on days 3 and 8. Generally, residues of the nine individual pesticides on storage cabbage, savoy cabbage, Chinese cabbage, and tah tsai did not differ significantly from day 1 to day 7 after application. Residue concentrations were generally significantly higher on bok choi than on the other cultivars. Residue deposits generally correlated with the rate of application; residues of captan, however, were about 50% of the predicted value. Significant differences in deposit and dissipation were observed among cultivars and pesticides, with dramatic initial decreases for diazinon and parathion. Because of their higher exposed surface area-to-mass ratios, leafier crops had higher residue concentrations than head varieties. Residues on lettuce cultivars were higher than on the

  16. Measurements of nitrous oxide emissions from vegetable production in China

    NASA Astrophysics Data System (ADS)

    Xiong, Zhengqin; Xie, Yingxin; Xing, Guangxi; Zhu, Zhaoliang; Butenhoff, Chris

    Nitrous oxide (N 2O) emissions resulting from Chinese vegetable production were measured. A site in suburban Nanjing (East coast; Jiangsu Province) was monitored from November 2001 to January 2003, in which five consecutive vegetable crops were sown. The crops consisted of radish, baby bok choy, lettuce, second planting of baby bok choy, and finally celery. Results suggested that N 2O emission events occur in pulses. The average N 2O-N flux for all five crops was 148±9 μg N m -2 h -1 and the average emission rate was 12±0.7 kg N ha -1. The average seasonal emission fluxes ranged from 37 μg N m -2 h -1 in the radish plot to 300 μg N m -2 h -1 in the celery plot. The celery field produced the greatest cumulative emission of 5.8 kg N ha -1 while the baby bok choy field had the lowest rate of 0.96-1.0 kg N ha -1. In total, 0.73% of applied fertilizer N was emitted as N 2O-N as a whole. The lettuce field had the largest emission factor of 2.2%. Results indicate that emissions from vegetable field are a potential source of national N 2O inventory. Temporal variation is much greater than spatial variation and the corresponding CV averaged 115% and 22%, respectively. Under the same total sampling quantity, increasing sampling frequency is more important than increasing spatial replicates.

  17. Diffusion and accumulation in cultivated vegetable plants of di-(2-ethylhexyl) phthalate (DEHP) from a plastic production factory.

    PubMed

    Du, Q Z; Wang, J W; Fu, X W; Xia, H L

    2010-08-01

    Di-(2-ethylhexyl) phthalate (DEHP) concentrations in the atmosphere and in four vegetable crops including Brassica chinensis L. (bok choy), Brassica campestris L. (field mustard), Vigna unguiculata Walp. (cowpea), and Solanum melongena L. (eggplant) cultivated on land surrounding a plastic production factory were determined. The air DEHP concentrations (means) at the sites 0.2, 0.4, 0.8, and 1.6 km away from the plastic production building were about 9.4-12.8, 5.8-9.6, 1.6-5.0, and 0.04-0.27 microg m(-3) dry weight (DW), respectively. Wind direction is a key factor influencing the measurable DEHP concentration of the air, which was highest in the downwind direction and lowest in the upwind direction, and thus the vegetables accumulated the highest DEHP contents in the downwind direction and the lowest quantities in the upwind direction. The highest DEHP accumulations content of bok choy, field mustard, eggplant, and cowpea were 52.0 +/- 3.1, 43.1 +/- 2.2, 36.2 +/- 2.8, and 19.4 +/- 0.47 mg kg(-1) DW, respectively. Safety estimation on the basis of the daily intake limit referenced by the US Environmental Protection Agency (USEPA) led to the conclusion that eating vegetables cultivated 0.2 km away from the plastic production building is not a food safety problem under normal conditions. A strong positive linear correlation between atmospheric DEHP concentration and DEHP content of the vegetable crops was found. The limits for air DEHP concentration for safe vegetable cultivation are 24.0, 34.8, 40.8, and 82.8 microg m(-3) for bok choy, field mustard, cowpea, and eggplant, respectively, by calculating from the equation of linear regression between air DEHP concentration and vegetable DEHP content. PMID:20496185

  18. Disruption of sphingolipid metabolism augments ceramide-induced autophagy in preeclampsia.

    PubMed

    Melland-Smith, Megan; Ermini, Leonardo; Chauvin, Sarah; Craig-Barnes, Hayley; Tagliaferro, Andrea; Todros, Tullia; Post, Martin; Caniggia, Isabella

    2015-04-01

    Bioactive sphingolipids including ceramides are involved in a variety of pathophysiological processes by regulating cell death and survival. The objective of the current study was to examine ceramide metabolism in preeclampsia, a serious disorder of pregnancy characterized by oxidative stress, and increased trophoblast cell death and autophagy. Maternal circulating and placental ceramide levels quantified by tandem mass spectrometry were elevated in pregnancies complicated by preeclampsia. Placental ceramides were elevated due to greater de novo synthesis via high serine palmitoyltransferase activity and reduced lysosomal breakdown via diminished ASAH1 expression caused by TGFB3-induced E2F4 transcriptional repression. SMPD1 activity was reduced; hence, sphingomyelin degradation by SMPD1 did not contribute to elevated ceramide levels in preeclampsia. Oxidative stress triggered similar changes in ceramide levels and acid hydrolase expression in villous explants and trophoblast cells. MALDI-imaging mass spectrometry localized the ceramide increases to the trophophoblast layers and syncytial knots of placentae from pregnancies complicated by preeclampsia. ASAH1 inhibition or ceramide treatment induced autophagy in human trophoblast cells via a shift of the BOK-MCL1 rheostat toward prodeath BOK. Pharmacological inhibition of ASAH1 activity in pregnant mice resulted in increased placental ceramide content, abnormal placentation, reduced fetal growth, and increased autophagy via a similar shift in the BOK-MCL1 system. Our results reveal that oxidative stress-induced reduction of lysosomal hydrolase activities in combination with elevated de novo synthesis leads to ceramide overload, resulting in increased trophoblast cell autophagy, and typifies preeclampsia as a sphingolipid storage disorder. PMID:25853898

  19. Disruption of sphingolipid metabolism augments ceramide-induced autophagy in preeclampsia

    PubMed Central

    Melland-Smith, Megan; Ermini, Leonardo; Chauvin, Sarah; Craig-Barnes, Hayley; Tagliaferro, Andrea; Todros, Tullia; Post, Martin; Caniggia, Isabella

    2015-01-01

    Bioactive sphingolipids including ceramides are involved in a variety of pathophysiological processes by regulating cell death and survival. The objective of the current study was to examine ceramide metabolism in preeclampsia, a serious disorder of pregnancy characterized by oxidative stress, and increased trophoblast cell death and autophagy. Maternal circulating and placental ceramide levels quantified by tandem mass spectrometry were elevated in pregnancies complicated by preeclampsia. Placental ceramides were elevated due to greater de novo synthesis via high serine palmitoyltransferase activity and reduced lysosomal breakdown via diminished ASAH1 expression caused by TGFB3-induced E2F4 transcriptional repression. SMPD1 activity was reduced; hence, sphingomyelin degradation by SMPD1 did not contribute to elevated ceramide levels in preeclampsia. Oxidative stress triggered similar changes in ceramide levels and acid hydrolase expression in villous explants and trophoblast cells. MALDI-imaging mass spectrometry localized the ceramide increases to the trophophoblast layers and syncytial knots of placentae from pregnancies complicated by preeclampsia. ASAH1 inhibition or ceramide treatment induced autophagy in human trophoblast cells via a shift of the BOK-MCL1 rheostat toward prodeath BOK. Pharmacological inhibition of ASAH1 activity in pregnant mice resulted in increased placental ceramide content, abnormal placentation, reduced fetal growth, and increased autophagy via a similar shift in the BOK-MCL1 system. Our results reveal that oxidative stress-induced reduction of lysosomal hydrolase activities in combination with elevated de novo synthesis leads to ceramide overload, resulting in increased trophoblast cell autophagy, and typifies preeclampsia as a sphingolipid storage disorder. PMID:25853898

  20. Uptake of di-(2-ethylhexyl) phthalate of vegetables from plastic film greenhouses.

    PubMed

    Fu, Xiaowei; Du, Qizhen

    2011-11-01

    Uptake of di-(2-ethylhexyl) phthalate (DEHP) of nine vegetables including potherb mustard, bok choy, celery, spinach, cabbage, leaf of tube, lettuce, garlic, and edible amaranth in plastic film greenhouses with different plastic films, film thickness, greenhouse age, and greenhouse height was studied. The results showed that the higher the DEHP content of film, the thicker the film, the lower the height of the greenhouse, and the younger the age of the greenhouse were, the higher the DEHP concentration of vegetables was. The results afford significant information for production of safe vegetables with low level DEHP contamination. PMID:21958198

  1. Honesty in Professional Activities

    NASA Astrophysics Data System (ADS)

    Ahearne, John F.

    2012-01-01

    Honesty is an important subject in science and philosophy. Nobel Laureate Michael Bishop: "Each of us builds our discoveries on the work of others; if that work is false, our constructions fall like a house of cards and we must start all over again.” Sissela Bok has written on the pervasiveness and destructive power of lying. Not only is dishonesty corrosive to other's efforts, it corrodes the dishonest person. In most professions, respect and trust by colleagues are critical in maintaining effective working relationships. Robert Fulghum described traits that should be learned in kindergarten. These include many that seem to be lacking in today's political, economic, and communications realms.

  2. Spectropolarimetry of ASASSN-14lp

    NASA Astrophysics Data System (ADS)

    Porter, Amber L.; Leising, Mark D.; Milne, Peter; Williams, Grant; Smith, Paul S.

    2016-01-01

    Spectropolarimetric observations which capture the degree of polarization as a function of wavelength help us to explore the aspherical nature of supernova explosions. Using the CCD Imaging/Spectropolarimeter (SPOL) at the 6.5-m MMT and 90" Bok telescopes, we obtained multi-epoch observations of the Type Ia supernova ASASSN-14lp from pre-maximum through late times. We confirm a low continuum polarization indicating a nearly spherical explosion and investigate how the evolution of the Si II 6355Å feature compares to other Type Ia supernovae.

  3. [N2O emission from an intensively managed greenhouse vegetable field in Nanjing suburb, Jiangsu Province of East China].

    PubMed

    Jia, Jun-Xiang; Zhang, Man; Xiong, Zheng-Qin; Li, Ye

    2012-03-01

    By using static opaque chamber and gas chromatography, this paper studied the dynamic changes of N2O fluxes and their relationships with soil temperature, soil moisture content, and soil nitrate and ammonium contents in an intensively managed greenhouse celery-Tung choy-Bok choy-amaranth rotation field and in a bare fallow land in Nanjing suburb. The cumulative N2O emission from the rotation vegetable field was as high as 137.2 kg N x hm(-2), being significantly higher than that from the bare fallow land (29.2 kg N x hm(-2)), and the N2O-N emission factor of the rotation vegetable field ecosystem was up to 4.6%. In the rotation field, the planting of Tung choy had the greatest contribution to the annual cumulative N2O emission, occupying 53.5% of the total, followed by the planting of Bok choy (31.9%), celery field (4.5%), and amaranth (4.8%). The N2O flux of the rotation field had significant positive correlation with soil temperature, the Q10 being 2.80, but no significant correlations with soil moisture content and soil nitrate and ammonium contents. PMID:22720619

  4. [Veterinary dentistry (6). From back to the roots to buck on the rock].

    PubMed

    van Foreest, A

    1992-10-01

    The Royal Netherlands Veterinary Association is organizing its yearly congress in the old city of Utrecht where all Dutch veterinarians have been graduated. 'Back to the roots' is the slogan of this meeting. The Diergeneeskundige Studenten Kring (the Dutch veterinary students association) is celebrating the 60th anniversary at the same time with the slogan: 'Bok on the rock.' On the first day of this celebration the students are organizing a symposium Veterinary Dentistry. The author has been inspired by the two slogans to a discourse in which the past and the future of animal dentistry is discussed. In 'Back to the Roots' history and anecdotes about dental treatments are presented. It is clear that dental treatment in animals is possible for every well-educated veterinarian. In 'De bok on the rock' the author shows the ropes how to develop a dental minded practice. Oral examination, a good knowledge of dentistry and a dental-minded staff are the most important factors to build up such a practice. There is an abundance of dental patients in every practice. An optimal client education and coaching is the best way to find them and to follow them. PMID:1412374

  5. Advanced Life Support Food Subsystem Salad Crop Requirements

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele H.; Stevens, Irene; Swango, Beverly E.; Toerne, Mary E.; Lane, Helen W. (Technical Monitor)

    2002-01-01

    As the National Aeronautics and Space Administration (NASA) begins to look towards longer duration space flights, the importance of fresh foods and varied menu choices increases. Long duration space missions require development of both a Transit Food System and a Lunar or Planetary Food System. These two systems are intrinsically different since the first one will be utilized in the transit vehicle in microgravity conditions while the second will be used in conditions of partial gravity (hypogravity). The Transit Food System will consist of prepackaged food of extended shelf life. Microgravity imposes significant limitations on the ability of the crew to handle food and allows only for minimal processing. Salad crops will be available for the planetary mission. Supplementing the transit food system with salad crops is also being considered. These crops will include carrots, tomatoes, lettuce, radish, spinach, chard, cabbage, and onion. The crops will be incorporated in the menu along with the prepackaged food. The fresh tasting salad crops will provide variety, texture, and color in the menu. This variety should provide increased psychological benefit. Preliminary studies on spinach, tomatoes, and bok choy have been completed. Sensory and analytical tests, including color and moisture were conducted on the chamber grown crops and compared to store bought spinach, tomatoes, and bok choy. Preliminary studies of the appropriate serving sizes and number of servings per week have also been conducted.

  6. Obituary: Raymond Edwin White Jr., 1933-2004

    NASA Astrophysics Data System (ADS)

    Liebert, James William

    2004-12-01

    traditions. Earlier in 1971-72, Ray served as Program Officer for Stars and Stellar Evolution in the Astronomy Section of the National Science Foundation. Ray was one of the three "originators" of "The Inspiration of Astronomical Phenomena" (INSAP) Conferences. These conferences provide scholarly discussions on the many and variegated cultural impacts of the perceptions about the day- and night-time sky, thus providing a forum for a broad sampling of artists, historians, philosophers, and scientists to get together, compare notes, and ask questions of one another. The INSAP Conferences have taken place near Castel Gandolfo Italy, on the island of Malta, near Palermo Italy, and at Oxford University in England. Ray's scholarship also was manifest in his activities as editor. For some years in the 1990s, he edited two astronomy journals, The Astronomy Quarterly and Vistas in Astronomy. Raymond E. White, Jr., is survived by his wife Ruby E. (nee Fisk), his high school sweetheart at Heidelberg High in Germany. Their children include Raymond E. White III (Professor of Physics and Astronomy at the University of Alabama, Tuscaloosa), Kathleen M. (White) Wade, and Kevin D. White. Ray was proud of two beautiful granddaughters, Charlotte R. Wade and Sarah E. Wade. Ray was proud of his early role with Steward Observatory Director Bart Bok in the commissioning of the "90-inch" reflector at the University of Arizona site on Kitt Peak in 1969. He built the direct camera, and was invited by his close friend Bok to share the "first light" of this telescope, now renamed the Bok 2.3-m telescope. When Professor Bok passed away, the astronomy magazine Sky & Telescope invited Ray to write an article which was entitled "Bart J. Bok (1906-83): Personal Memoir from a Grandson." (Bok mentored Ivan R. King, who was Ray's thesis advisor.) In his concluding remarks, Ray wrote, "The aspect of Bart J. Bok I will miss the most is his exuberance for the art of astronomy." We will also miss greatly this

  7. Cygnus X-3 Little Friend's Counterpart, the Distance to Cygnus X-3 and Jets (Oh My!)

    NASA Astrophysics Data System (ADS)

    McCollough, Michael L.; Dunham, Michael M.; Corrales, Lia

    2016-04-01

    Chandra observations have revealed a feature within 16" of Cygnus X-3 which varied in phase with Cygnus X-3. This feature was shown to be a Bok globule which is along the line of sight to Cygnus X-3. We report onobservations made with Submillimeter Array (SMA) to search for molecular emission from this globule, also known as Cygnus X-3's "little friend." We have found a counterpart in both 12CO and 13CO emission. From the velocity shift of the molecular lines we are able determine a kinematic distance to the little friend and in turn a distance to Cygnus X-3. The uncertainties in this distance estimate to Cygnus X-3 are less than 10%. An additional unexpected discovery was that Cygnus X-3 is not the only source to have jets!

  8. Time Monitoring Variability of Classical Be Stars

    NASA Astrophysics Data System (ADS)

    Kuhn, Benjamin; Eisner, Joshua A.; Stone, Jordan

    2016-01-01

    Classical Be stars are B type stars that show hydrogen emission in their spectra, and exhibit variability across the electromagnetic spectrum, including visible and infrared wavelengths. While spectroscopic variability in the optical range has been studied previously, the near infrared region has not been investigated as thoroughly. We present multiple epochs of near infrared spectroscopy for a sample of eight Classical Be stars. Our observations were taken using the FSPEC instrument on the 90-inch Bok reflector telescope at Kitt Peak during the months of May and June of 2010 and 2011. We targeted the Brackett Gamma emission line of hydrogen with a resolution of ≈3500. Using Python we developed tools to analyze the reduced and calibrated spectra, as well as compute equivalent widths. Time-series spectra indicate that a majority of the systems exhibit spectroscopic variability. By monitoring the strengths of the emission feature over time we aim to constrain the physical properties of these systems.

  9. Historical Notes on the Dutch and American-Dutch "schools" in Astronomy and Their Relations with Physics

    NASA Astrophysics Data System (ADS)

    van den Heuvel, Ed

    2006-04-01

    Dutch astronomy and physics experienced two "golden ages". The firstone covered the 17th century, culminating with Christiaan Huygens,inventor of the pendulum clock and the wave theory of light, anddiscoverer of Saturn's rings and largest satellite Titan. The secondone, which lasts till the present, started around 1880 withphysicists Lorentz, van der Waals, Zeeman and Kamerlingh Onnes andastronomer Kapteijn and his pupils De Sitter, van Rhijn, Oort andSchilt. Kapteijn, through his friendship with George Ellery Hale,initiated the strong connection between American and Dutch astronomy,which led to the rise of many Dutch-born astronomers to prominentpositions in the US, from Luyten, Bok, Brouwer, Schilt and Kuiperto Woltjer, Gehrels, and Beckers. The rise of the second "goldenage" appears to be closely related to drastic reforms in the Dutchhigh school and university systems in the last decades of the 19thcentury.

  10. The Dark Energy Spectroscopic Instrument (DESI): The NOAO DECam Legacy Imaging Survey and DESI Target Selection

    NASA Astrophysics Data System (ADS)

    Schlegel, David J.; Blum, Robert D.; Castander, Francisco Javier; Dey, Arjun; Finkbeiner, Douglas P.; Foucaud, Sebastien; Honscheid, Klaus; James, David; Lang, Dustin; Levi, Michael; Moustakas, John; Myers, Adam D.; Newman, Jeffrey; Nord, Brian; Nugent, Peter E.; Patej, Anna; Reil, Kevin; Rudnick, Gregory; Rykoff, Eli S.; Ford Schlafly, Eddie; Stark, Casey; Valdes, Francisco; Walker, Alistair R.; Weaver, Benjamin; DECam Legacy Survey Collaboration

    2015-01-01

    The DECam Legacy Survey will conduct a 3-band imaging survey of the Sloan Digital Sky Survey (SDSS) extragalactic footprint. The Dark Energy Camera (DECam) will be used to image the 6700 square degree footprint overlapping SDSS in the region -20 < Dec < +30 deg, to depths of g=24.7, r=23.9, z=23.0. The survey will be conducted from Fall 2014 through Spring 2017, with periodic data releases beginning in March 2015. These releases will include catalogs constructed with the Tractor-based multi-wavelength forced photometry applied to the DECam and WISE satellite data.The Dark Energy Spectroscopic Instrument (DESI) will observe 24 million galaxies and quasars in a 14,000 square degree extragalactic footprint. The targeting in that footprint will be provided by a combination of these DECam data, the MOSAIC camera on the Mayall 4-meter, and the 90Prime camera on the Bok Telescope.

  11. Rapid CIV BAL Variability in an SDSS-RM Quasar

    NASA Astrophysics Data System (ADS)

    Grier, Catherine; Hall, Patrick B.; Brandt, W. Niel; Trump, Jonathan; Shen, Yue; Vivek, M.

    2015-01-01

    The Sloan Digital Sky Survey Reverberation Mapping Project (SDSS-RM) recently completed its first round of spectroscopic observations of a sample of ~850 quasars with the SDSS-III BOSS spectrograph. From 2014 January-July, more than 30 epochs of spectroscopy were obtained for this quasar sample, and supporting observations were carried out at the Canada-France-Hawaii Telescope and the Steward Observatory Bok telescope. A number of quasars observed as a part of this project have broad absorption line (BAL) features in their spectra; we here report on observations of one such target that displays very rapid BAL variability --- the CIV trough is variable on rest frame timescales shorter than a few days. We will discuss the observed short-timescale variability of this BAL and the implications for the physical environment and physics regulating BALs in active galactic nuclei.

  12. CYGNUS X-3's LITTLE FRIEND

    SciTech Connect

    McCollough, M. L.; Smith, R. K.; Valencic, L. A.

    2013-01-01

    Using the unique X-ray imaging capabilities of the Chandra X-ray observatory, a 2006 observation of Cygnus X-3 has provided insight into a singular feature associated with this well-known microquasar. This extended emission, located {approx}16'' from Cygnus X-3, varies in flux and orbital phase (shifted by 0.56 in phase) with Cygnus X-3, acting like a celestial X-ray 'mirror'. The feature's spectrum, flux, and time variations allow us to determine the location, size, density, and mass of the scatterer. We find that the scatterer is a Bok Globule located along our line of sight, and we discuss its relationship to Cygnus X-3. This is the first time such a feature has been identified with Chandra.

  13. Radial systems of dark globules

    SciTech Connect

    Gyul'budagyn, A.L.

    1986-03-01

    The author gives examples of radial systems consisting of dark globules and ''elephant trunks''. Besides already known systems, which contain hot stars at their center, data are given on three radial systems of a new kind, at the center of which there are stars of spectral types later than B. Data are given on 32 globules of radial systems of the association Cep OB2. On the basis of the observational data, it is concluded that at least some of the isolated Bok globules derive from elephant trunks and dark globules forming radial systems around hot stars. It is also suggested that the two molecular clouds situated near the Rosette nebula and possessing velocities differing by ca 20 km/sec from the velocity of the nebula could have been ejected in opposite directions from the center of the nebula. One of these clouds consists of dark globules forming the radial system of the Rosette nebula.

  14. Attenuation of Carcinogenesis and the Mechanism Underlying by the Influence of Indole-3-carbinol and Its Metabolite 3,3′-Diindolylmethane: A Therapeutic Marvel

    PubMed Central

    Maruthanila, V. L.; Poornima, J.; Mirunalini, S.

    2014-01-01

    Rising evidence provides credible support towards the potential role of bioactive products derived from cruciferous vegetables such as broccoli, cauliflower, kale, cabbage, brussels sprouts, turnips, kohlrabi, bok choy, and radishes. Many epidemiological studies point out that Brassica vegetable protects humans against cancer since they are rich sources of glucosinolates in addition to possessing a high content of flavonoids, vitamins, and mineral nutrients. Indole-3-carbinol (I3C) belongs to the class of compounds called indole glucosinolate, obtained from cruciferous vegetables, and is well-known for tits anticancer properties. In particular, I3C and its dimeric product, 3,3′-diindolylmethane (DIM), have been generally investigated for their value against a number of human cancers in vitro as well as in vivo. This paper reviews an in-depth study of the anticancer activity and the miscellaneous mechanisms underlying the anticarcinogenicity thereby broadening its therapeutic marvel. PMID:24982671

  15. Attenuation of Carcinogenesis and the Mechanism Underlying by the Influence of Indole-3-carbinol and Its Metabolite 3,3'-Diindolylmethane: A Therapeutic Marvel.

    PubMed

    Maruthanila, V L; Poornima, J; Mirunalini, S

    2014-01-01

    Rising evidence provides credible support towards the potential role of bioactive products derived from cruciferous vegetables such as broccoli, cauliflower, kale, cabbage, brussels sprouts, turnips, kohlrabi, bok choy, and radishes. Many epidemiological studies point out that Brassica vegetable protects humans against cancer since they are rich sources of glucosinolates in addition to possessing a high content of flavonoids, vitamins, and mineral nutrients. Indole-3-carbinol (I3C) belongs to the class of compounds called indole glucosinolate, obtained from cruciferous vegetables, and is well-known for tits anticancer properties. In particular, I3C and its dimeric product, 3,3'-diindolylmethane (DIM), have been generally investigated for their value against a number of human cancers in vitro as well as in vivo. This paper reviews an in-depth study of the anticancer activity and the miscellaneous mechanisms underlying the anticarcinogenicity thereby broadening its therapeutic marvel. PMID:24982671

  16. Brassica vegetables and prostate cancer risk: a review of the epidemiological evidence.

    PubMed

    Kristal, Alan R; Lampe, Johanna W

    2002-01-01

    Epidemiological studies have yielded conflicting results on the associations of diet with prostate cancer. We review evidence that Brassica vegetables are associated with reduced prostate cancer risk. Brassica vegetables, which include broccoli, cabbage, mustard and collard greens, and bok choy, contain glucosinolates, the metabolic breakdown products of which are potent modulators of xenobiotic-metabolizing enzymes that protect DNA from damage. Twelve published studies give some information about Brassica vegetables and prostate cancer risk; six of these studies can be clearly interpreted. Of these, three reported statistically significant reduced risks (P < 0.05) and one reported a borderline significant reduced risk (P = 0.06) with high Brassica vegetable consumption. The epidemiological literature provides modest support for the hypothesis that high intakes of Brassica vegetables reduce prostate cancer risk. PMID:12235639

  17. Spectroscopic Classification of AT2016cvv as a normal Type Ia Supernova

    NASA Astrophysics Data System (ADS)

    Leonard, D. C.; Sheehan, P.; McCarthy, D.; Follette, K.; Moustakas, J.; Alaniz, M.; Beaumont, C.; Batterman, T.; Black, E.; Bowers, T.; Cryder, M.; Davis, C.; Dawsey, R.; Douglas, E.; Gordon, S.; Gramze, S.; Greiner, M.; Hart, K.; Holt, A.; Hu, J.; Ingebretsen, C.; Iyer, D.; Josephson, R.; Kapko, A.; Keane, J.; Kimberlin, T.; Kinman, S.; Klusmeyer, J.; Kolderup, E.; Kresina, K.; Madden, M.; Meiman, E.; Miniconi, S.; Morton, A.; Neumann, K.; Noguerra, T.; Regester, B.; Regester, J.; Rosenthal, M.; Schlingman, A.; Schlingman, W.; Schlingman, W.; Smith, A.; Svoboda, B.; Watson, L.; Whitesell, R.

    2016-06-01

    We report spectroscopic classification of AT2016cvv (also known as PTSS-16ijc), discovered 2016 June 16.709 UT by the PMO-Tsinghua Supernova Survey (PTSS) in CGCG 280-024 (z=0.044571; Falco et al. 1999, PASP 111, 438, via NED), through inspection of an optical spectrum (range 370-690 nm, resolution 0.8 nm) obtained with the 2.3-m Bok telescope (+ Boller & Chivens spectrograph) at Kitt Peak on 2016 June 19.347 UT. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, ApJ, 666, 1024) and GELATO (Harutyunyan et al. 2008, A & A, 488, 383) finds convincing spectral matches with a number of normal Type-Ia supernovae a few days before maximum light.

  18. Spectroscopic Classification of AT2016cvw as a normal Type Ia Supernova

    NASA Astrophysics Data System (ADS)

    Leonard, D. C.; Sheehan, P.; McCarthy, D.; Follette, K.; Moustakas, J.; Alaniz, M.; Beaumont, C.; Batterman, T.; Black, E.; Bowers, T.; Cryder, M.; Davis, C.; Dawsey, R.; Douglas, E.; Gordon, S.; Gramze, S.; Greiner, M.; Hart, K.; Holt, A.; Hu, J.; Ingebretsen, C.; Iyer, D.; Josephson, R.; Kapko, A.; Keane, J.; Kimberlin, T.; Kinman, S.; Klusmeyer, J.; Kolderup, E.; Kresina, K.; Madden, M.; Meiman, E.; Miniconi, S.; Morton, A.; Neumann, K.; Noguerra, T.; Regester, B.; Regester, J.; Rosenthal, M.; Schlingman, A.; Schlingman, W.; Schlingman, W.; Smith, A.; Svoboda, B.; Watson, L.; Whitesell, R.

    2016-06-01

    We report spectroscopic classification of AT2016cvw (also known as PTSS-16ipw), discovered 2016 June 18.813 UT by the PMO-Tsinghua Supernova Survey (PTSS) in MCG +02-58-008 (z=0.038877; Huchra et al. 2012, ApJS, 199, 26, via NED), through inspection of an optical spectrum (range 370-690 nm, resolution 0.8 nm) obtained with the 2.3-m Bok telescope (+ Boller & Chivens spectrograph) at Kitt Peak on 2016 June 20.423 UT. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, ApJ, 666, 1024) and GELATO (Harutyunyan et al. 2008, A & A, 488, 383) finds convincing spectral matches with a number of normal Type-Ia supernovae roughly 3 days before maximum light.

  19. Cygnus X-3's Little Friend

    NASA Technical Reports Server (NTRS)

    McCollough, M. L.; Smith, R. K.; Valencic, L. A.

    2010-01-01

    Using the unique X-ray imaging capabilities of the Chandra X-ray observatory, a 2006 observation of Cygnus X-3 has provided insight into a singular feature associated with this well-known microquasar. This extended emission, located approx.16" from Cygnus X-3, varies in flux and orbital phase (shifted by 0.56 in phase) with Cygnus X-3, acting like a celestial X-ray "mirror." The feature s spectrum, flux, and time variations allow us to determine the location, size, density, and mass of the scatterer. We find that the scatterer is a Bok Globule located along our line of sight, and we discuss its relationship to Cygnus X-3. This is the first time such a feature has been identified with Chandra.

  20. Spectropolarimetry of SN 2011fe

    NASA Astrophysics Data System (ADS)

    Milne, Peter; Williams, G.; Smith, P. S.; Smith, N.

    2014-01-01

    The Supernova Spectropolarimetry Project is a recently formed collaboration between observers and theorists that focuses on decoding the complex, time-dependent spectropolarimetric behavior of supernovae (SNe) of all types. Using the CCD Imaging/Spectropolarimeter (SPOL) at the 61" Kuiper, the 90" Bok, and the 6.5-m MMT telescopes, we obtain multi-epoch observations of each target, aiming to construct the most comprehensive survey to date of supernovae in polarized light. We present spectropolarimetry of SN 2011fe obtained for 8 epochs from August 2011-April 2012. The near-peak spectra show the evolution of the SiIIλ6355Å feature, as well as other polarized line features. The late nebular spectra show the line ratios and line profiles of the forbidden iron-peak elements. The spectral series permit estimation of the interstellar polarization. Collectively, these observations permit a study of the evolution of the emission from a NUV-blue type Ia supernova.

  1. A measurement of the hyperfine structure of CO-17

    NASA Technical Reports Server (NTRS)

    Frerking, M. A.; Langer, W. D.

    1981-01-01

    It is pointed out that the isotope of carbon monoxide, CO-17, has appreciable hyperfine structure caused by the electric quadrupole and the magnetic dipole interactions of the O-17 nucleus which has a spin of 5/3. During a radioastronomical study of the structure and dynamics of cold interstellar clouds, it was found that the Bok globule B335 had an extremely small velocity dispersion such that the hyperfine components are clearly resolved. A graph is provided which shows the antenna temperature (a measure of intensity) of the CO-17 emission as a function of frequency. The hyperfine constants and line frequencies were redetermined for the CO-17 J=1 yields 0 rational transition. The observation of CO-17 was carried out with a 7 meter Cassegrain antenna during 1979 and 1980. The CO-17 molecular line parameters are listed in a table.

  2. Methoxychlor induces atresia by altering Bcl2 factors and inducing caspase activity in mouse ovarian antral follicles in vitro

    PubMed Central

    Basavarajappa, Mallikarjuna S.; Karman, Bethany N.; Wang, Wei; Gupta, Rupesh K.; Flaws, Jodi A.

    2012-01-01

    Methoxychlor (MXC) is an organochlorine pesticide widely used in many countries against various species of insects that attack crops and domestic animals. MXC reduces fertility by increasing atresia (death) of antral follicles in vivo. MXC also induces atresia of antral follicles after 96 h in vitro. The current work tested the hypothesis that MXC induces morphological atresia at early time points (24 and 48 h) by altering pro-apoptotic (Bax, Bok, Casp3, and caspase activity) and anti-apoptotic (Bcl2 and Bcl-xL) factors in the follicles. The results indicate that at 24 h, MXC increased Bcl-xL and Bax mRNA levels and increased the ratio of Bax/Bcl2. At 48–96 h, MXC induced morphological atresia. At 24–96 h, MXC increased caspase activities. These data suggest that MXC may induce atresia by altering Bcl2 factors and inducing caspase activities in antral follicles. PMID:23000595

  3. South Galactic Cap u-band Sky Survey (SCUSS): Data Release

    NASA Astrophysics Data System (ADS)

    Zou, Hu; Zhou, Xu; Jiang, Zhaoji; Peng, Xiyan; Fan, Dongwei; Fan, Xiaohui; Fan, Zhou; He, Boliang; Jing, Yipeng; Lesser, Michael; Li, Cheng; Ma, Jun; Nie, Jundan; Shen, Shiyin; Wang, Jiali; Wu, Zhenyu; Zhang, Tianmeng; Zhou, Zhimin

    2016-02-01

    The South Galactic Cap u-band Sky Survey (SCUSS) is a deep u-band imaging survey in the south Galactic cap using the 2.3 m Bok telescope. The survey observations were completed at the end of 2013, covering an area of about 5000 square degrees. We release the data in the region with an area of about 4000 deg2 that is mostly covered by the Sloan digital sky survey. The data products contain calibrated single-epoch images, stacked images, photometric catalogs, and a catalog of star proper motions derived by Peng et al. The median seeing and magnitude limit (5σ) are about 2.″0 and 23.2 mag, respectively. There are about 8 million objects having measurements of absolute proper motions. All the data and related documentations can be accessed through the SCUSS data release website http://batc.bao.ac.cn/Uband/data.html.

  4. Origin of Variability of a White Dwarf in the Kepler Field

    NASA Astrophysics Data System (ADS)

    Hoard, Donald W.; Howell, Steve B.

    2015-01-01

    KIC 9535405 (= BOKS 53856) is a hot (34,000 K), DA (hydrogen-atmosphere) white dwarf in the Kepler field. It was initially identified in the Burrell Optical Kepler Survey (BOKS) as a blue variable object with an approximately 6-hr modulation. Subsequent multi-band photometry and spectroscopy revealed it to be a blue star with the characteristic broad Balmer lines of a hot DA white dwarf (Feldmeier et al. 2011). It is too faint to have been detected in the Two Micron All Sky Survey (2MASS) and the Wide-field Infrared Survey Explorer (WISE) All Sky Survey, and is located in an area of the sky not covered by the Galaxy Evolution Explorer (GALEX). Further, no known X-ray sources are co-incident with KIC 9535405. Kepler observations for 89 days at short cadence in 2009 refined the variability to a non-sinusoidal and asymmetric, but repeating, profile with a period of 6.138 hr and a maximum semi-amplitude of 2.5% (Holberg & Howell 2011). We present a preliminary analysis of new photometric and spectroscopic observations of KIC 9535405 obtained from the ground (during 2012-2014), the Spitzer Space Telescope (Jan 2013), and the Hubble Space Telescope (Sep 2014), as well as a serendipitous UV observation by Swift (Jul 2010). A likely explanation for the observed variability involves confinement of metals in the photosphere of the white dwarf around its magnetic pole(s), which produces a relatively cool "dark spot" viewed as the white dwarf rotates.

  5. The development of WIFIS: a wide integral field infrared spectrograph

    NASA Astrophysics Data System (ADS)

    Sivanandam, Suresh; Chou, Richard C. Y.; Moon, Dae-Sik; Ma, Ke; Millar-Blanchaer, Maxwell; Eikenberry, Stephen S.; Chun, Moo-Young; Kim, Sang Chul; Raines, Steven N.; Eisner, Joshua

    2012-09-01

    We present the current results from the development of a wide integral field infrared spectrograph (WIFIS). WIFIS offers an unprecedented combination of etendue and spectral resolving power for seeing-limited, integral field observations in the 0.9 - 1.8 μm range and is most sensitive in the 0.9 - 1.35 μ,m range. Its optical design consists of front-end re-imaging optics, an all-reflective image slicer-type, integral field unit (IFU) called FISICA, and a long-slit grating spectrograph back-end that is coupled with a HAWAII 2RG focal plane array. The full wavelength range is achieved by selecting between two different gratings. By virtue of its re-imaging optics, the spectrograph is quite versatile and can be used at multiple telescopes. The size of its field-of-view is unrivalled by other similar spectrographs, offering a 4.511x 1211 integral field at a 10-meter class telescope (or 2011 x 5011 at a 2.3-meter telescope). The use of WIFIS will be crucial in astronomical problems which require wide-field, two-dimensional spectroscopy such as the study of merging galaxies at moderate redshift and nearby star/planet-forming regions and supernova remnants. We discuss the final optical design of WIFIS, and its predicted on-sky performance on two reference telescope platforms: the 2.3-m Steward Bok telescope and the 10.4-m Gran Telescopio Canarias. We also present the results from our laboratory characterization of FISICA. IFU properties such as magnification, field-mapping, and slit width along the entire slit length were measured by our tests. The construction and testing of WIFIS is expected to be completed by early 2013. We plan to commission the instrument at the 2.3-m Steward Bok telescope at Kitt Peak, USA in Spring 2013.

  6. The Mayall z-band Legacy Survey

    NASA Astrophysics Data System (ADS)

    Silva, David R.; Blum, Robert D.; Allen, Lori; Dey, Arjun; Schlegel, David J.; Lang, Dustin; Moustakas, John; Meisner, Aaron M.; Valdes, Francisco; Patej, Anna; Myers, Adam D.; Sprayberry, David; Saha, Abi; Olsen, Knut A.; Safonova, Sasha; Yang, Qian; Burleigh, Kaylan J.; MzLS Team

    2016-06-01

    The Mayall z-band Legacy Survey (MzLS) is conducting a deep z-band imaging survey covering 5000 square degrees in the north Galactic cap as part of the Legacy Survey, which is associated with the Dark Energy Spectroscopic Instrument (DESI) redshift survey. The Legacy Survey covers 14000 square degrees in the g, r, and z bands and is being executed on the Blanco 4-m, Mayall 4-m, and Bok 2.3-m telescopes. The MzLS footprint will be observed in the g and r bands using the Bok 2.3-m telescope also on Kitt Peak. The Beijing Arizona Sky Survey (BASS) is being conducted by a parallel team from Beijing and the University of Arizona. MzLS will cover the sky north of declination 30 degrees and reach a depth of z=23.0. The survey began in January 2016 and will run through June 2017 comprising approximately 230 nights on the Mayall telescope. The data are being obtained with an upgraded Mosaic camera that deploys with newred-sensitive CCDs from Lawrence Berkeley Lab (LBL) whose throughput is in excess of 80% at 8000 to approximately 9800 Angstrom. The upgrade project was a collaboration of Yale, LBL, and NOAO. MzLS images are public as soon as they are taken and delivered to the NOAO archive. Catalogs based on Tractor photometry for all available Legacy Survey images are released soon after they are constructed and MzLS sources will be included in next release planned for summer 2016. The Dark Energy Spectroscopic Instrument (DESI) will observe 30+ million galaxies and quasars in a 14,000 square degree extragalactic footprint. The targeting in that footprint will be provided by a combination of these MzLS data, DECam data from the DECam Legacy Survey, and data from the BASS survey.

  7. The DECam Legacy Survey

    NASA Astrophysics Data System (ADS)

    Blum, Robert D.; Burleigh, Kaylan; Dey, Arjun; Schlegel, David J.; Meisner, Aaron M.; Levi, Michael; Myers, Adam D.; Lang, Dustin; Moustakas, John; Patej, Anna; Valdes, Francisco; Kneib, Jean-Paul; Huanyuan, Shan; Nord, Brian; Olsen, Knut A.; Delubac, Timothée; Saha, Abi; James, David; Walker, Alistair R.; DECaLS Team

    2016-06-01

    The DECam Legacy Survey (DECaLS) is conducting a 3-band imaging survey of the Sloan Digital Sky Survey (SDSS) extragalactic footprint as part of the Legacy Survey, which is associated with the Dark Energy Spectroscopic Instrument (DESI) redshift survey. The Legacy Survey covers 14000 square degrees in the g, r, and z bands and is being executed on the Blanco 4-m, Mayall 4-m, and Bok 2.3-m telescopes. For DECaLS, the Dark Energy Camera (DECam) will image the footprint overlapping SDSS in the region -20 < Dec < +30 deg, to depths of g=24.7, r=23.9, z=23.0 and will eventually cover a total of 7500 square degrees. The survey began in 2014 and will run through Spring 2017. Images and catalogs were introduced in Public Data Release 2 (DR2), which occurred in January 2016. The algorithm "Tractor" applies multi-wavelength forced photometry to DECam and WISE data to produce galaxy (and star) magnitudes (as well as shape and other information) for the catalogs. In total, the optical data in DR2 cover a disjoint footprint in 2078, 2141 and 5322 square degrees in g, r, and z bands, respectively; 1807 square degrees has been observed in all three optical filters. There are approximately 260 million unique sources in DR2 spread over 97,554 0.25 x 0.25 square degree bricks.The Dark Energy Spectroscopic Instrument (DESI) will observe 30+ million galaxies and quasars in a 14,000 square degree extragalactic footprint. The targeting in that footprint will be provided by a combination of these DECam data, the MOSAIC camera on the Mayall 4-meter, and the 90Prime camera on the Bok telescope.

  8. Sound-triggered collapse of stably oscillating low-mass cores in a two-phase interstellar medium

    NASA Astrophysics Data System (ADS)

    Zhang, Ui-Han; Schive, Hsi-Yu; Chiueh, Tzihong

    2015-05-01

    Inspired by Barnard 68, a Bok globule, that undergoes stable oscillations, we perform multiphase hydrodynamic simulations to analyse the stability of Bok globules. We show that a high-density soft molecular core, with an adiabatic index γ = 0.7 embedded in a warm isothermal diffuse gas, must have a small density gradient to retain the stability. Despite being stable, the molecular core can still collapse spontaneously as it will relax to develop a sufficiently large density gradient after tens of oscillations, or a few 107 yr. However, during its relaxation, the core may abruptly collapse triggered by the impingement of small-amplitude, long-wavelength (˜6-36 pc) sound waves in the warm gas. This triggered collapse mechanism is similar to a sonoluminescence phenomenon, where underwater ultrasounds can drive air bubble coalescence. The collapse configuration is found to be different from both inside-out and outside-in models of low-mass star formation; none the less the mass flux is close to the prediction of the inside-out model. The condition and the efficiency for this core collapse mechanism are identified. Generally speaking, a broad-band resonance condition must be met, where the core oscillation frequency and the wave frequency should match each other within a factor of several. A consequence of our findings predicts the possibility of propagating low-mass star formation, for which collapse of cores, within a mass range short of one order of magnitude, takes place sequentially tracing the wavefront across a region of few tens of pc over 107 yr.

  9. Cisplatin Inhibits Hippocampal Cell Proliferation and Alters the Expression of Apoptotic Genes

    PubMed Central

    Manohar, Senthilvelan; Jamesdaniel, Samson; Salvi, Richard

    2014-01-01

    The hippocampus, which is critical for memory and spatial navigation, contains a proliferating stem cell niche that is especially vulnerable to anti-neoplastic drugs such as cisplatin. Although the damaging effects of cisplatin have recently been recognized, the molecular mechanisms underlying its toxic effects on this vital region are largely unknown. Using a focused apoptosis gene array, we analyzed the early cisplatin-induced changes in gene expression in the hippocampus of adult Sprague-Dawley rats and compared the results to those from the inferior colliculus, a non-mitotic auditory region resistant to cisplatin-induced cell death. Two days after a 12 mg/kg dose of cisplatin, significant increases were observed in five proapoptotic genes Bik, Bid, Bok, Trp53p2 and Card6 and a significant decrease in one antiapoptotic gene Bcl2a1. In contrast, Nol3, an antiapoptotic gene showed a significant increase in expression. The cisplatin-induced increase in Bid mRNA and decrease in Bcl2a1 mRNA was accompanied by a corresponding increase and decrease of their respective proteins in the hippocampus. In contrast, the cisplatin-induced changes in Bcl2a1, Bid, Bik and Bok gene expression in the inferior colliculus were strikingly different from those in the hippocampus consistent with the greater susceptibility of the hippocampus to cisplatin toxicity. Cisplatin also significantly reduced immunolabeling of the cell proliferation marker Ki67 in the subgranular zone (SGZ) of the hippocampus two days post treatment. These results indicate that cisplatin-induced hippocampal cell death is mediated by increased expression of proapoptotic and antiapoptotic genes and proteins that likely inhibit hippocampal cell proliferation. PMID:24277158

  10. Scientists Look at 2010: Carrying on Margaret Mayall's Legacy of Debunking Pseudoscience

    NASA Astrophysics Data System (ADS)

    Larsen, Krinstine

    2010-06-01

    In 1941 Margaret Mayall, the future director of the AAVSO, and Harvard colleague Bart Bok authored a critical study of astrology and its impact on society entitled "Scientists Look at Astrology." They chastised the scientific community for thinking the debunking of astrology to be "below the dignity of scientists." In contrast, they opined that it is one of the duties of scientists to "inform the public about the nature and background of a current fad, such as astrology, even though to do so may be unpleasant." Fast-forward 68 years in the future, and the astronomical community now faces a pseudoscientific enemy just as insidious as astrology, yet just as ignored by the general professional and amateur community as astrology had been when Mayall and Bok took up the charge in 1941. The pseudoscience in question is the well-publicized "prediction" that the Mayan calendar will end on December 21, 2012, causing the end of civilization in concert with one of a number of possible astronomical calamities, including (but not limited to) the gravitational pull of the center of the Milky Way (somehow enhanced by an "alignment" with our solar system), the near-approach by a mythical 10th planet (often named Nibiru), large-scale damage to the planet by solar flares larger than those ever recorded, or the shifting of the earth's axis of rotation (often confused with a proposed sudden and catastrophic reversal of the earth's magnetic polarity). As a scientific and educational organization, the AAVSO and its members have a responsibility to follow in Mayall's footsteps, shining the light of reason and knowledge on the dark corners of ignorance which far too often permeate the Internet, radio and television programming, and recent films, most notably 2012. This talk will highlight some of the basic premises of the 2012 hysteria and suggest ways that the AAVSO and its members can use variable stars and the history of the AAVSO to counteract some of the astronomical misinformation

  11. Multicolor Photometry of the Merging Galaxy Cluster A2319: Dynamics and Star Formation Properties

    NASA Astrophysics Data System (ADS)

    Yan, Peng-Fei; Yuan, Qi-Rong; Zhang, Li; Zhou, Xu

    2014-05-01

    Asymmetric X-ray emission and a powerful cluster-scale radio halo indicate that A2319 is a merging cluster of galaxies. This paper presents our multicolor photometry for A2319 with 15 optical intermediate filters in the Beijing-Arizona-Taiwan-Connecticut (BATC) system. There are 142 galaxies with known spectroscopic redshifts within the viewing field of 58' × 58' centered on this rich cluster, including 128 member galaxies (called sample I). A large velocity dispersion in the rest frame, 1622^{+91}_{-70} km s-1, suggests merger dynamics in A2319. The contour map of projected density and localized velocity structure confirm the so-called A2319B substructure, at ~10' northwest to the main concentration A2319A. The spectral energy distributions (SEDs) of more than 30,000 sources are obtained in our BATC photometry down to V ~ 20 mag. A u-band (~3551 Å) image with better seeing and spatial resolution, obtained with the Bok 2.3 m telescope at Kitt Peak, is taken to make star-galaxy separation and distinguish the overlapping contamination in the BATC aperture photometry. With color-color diagrams and photometric redshift technique, 233 galaxies brighter than h BATC = 19.0 are newly selected as member candidates after an exclusion of false candidates with contaminated BATC SEDs by eyeball-checking the u-band Bok image. The early-type galaxies are found to follow a tight color-magnitude correlation. Based on sample I and the enlarged sample of member galaxies (called sample II), subcluster A2319B is confirmed. The star formation properties of cluster galaxies are derived with the evolutionary synthesis model, PEGASE, assuming a Salpeter initial mass function and an exponentially decreasing star formation rate (SFR). A strong environmental effect on star formation histories is found in the manner that galaxies in the sparse regions have various star formation histories, while galaxies in the dense regions are found to have shorter SFR time scales, older stellar ages, and

  12. Multicolor photometry of the merging galaxy cluster A2319: Dynamics and star formation properties

    SciTech Connect

    Yan, Peng-Fei; Yuan, Qi-Rong; Zhang, Li; Zhou, Xu E-mail: yuanqirong@njnu.edu.cn

    2014-05-01

    Asymmetric X-ray emission and a powerful cluster-scale radio halo indicate that A2319 is a merging cluster of galaxies. This paper presents our multicolor photometry for A2319 with 15 optical intermediate filters in the Beijing-Arizona-Taiwan-Connecticut (BATC) system. There are 142 galaxies with known spectroscopic redshifts within the viewing field of 58' × 58' centered on this rich cluster, including 128 member galaxies (called sample I). A large velocity dispersion in the rest frame, 1622{sub −70}{sup +91} km s{sup –1}, suggests merger dynamics in A2319. The contour map of projected density and localized velocity structure confirm the so-called A2319B substructure, at ∼10' northwest to the main concentration A2319A. The spectral energy distributions (SEDs) of more than 30,000 sources are obtained in our BATC photometry down to V ∼ 20 mag. A u-band (∼3551 Å) image with better seeing and spatial resolution, obtained with the Bok 2.3 m telescope at Kitt Peak, is taken to make star-galaxy separation and distinguish the overlapping contamination in the BATC aperture photometry. With color-color diagrams and photometric redshift technique, 233 galaxies brighter than h {sub BATC} = 19.0 are newly selected as member candidates after an exclusion of false candidates with contaminated BATC SEDs by eyeball-checking the u-band Bok image. The early-type galaxies are found to follow a tight color-magnitude correlation. Based on sample I and the enlarged sample of member galaxies (called sample II), subcluster A2319B is confirmed. The star formation properties of cluster galaxies are derived with the evolutionary synthesis model, PEGASE, assuming a Salpeter initial mass function and an exponentially decreasing star formation rate (SFR). A strong environmental effect on star formation histories is found in the manner that galaxies in the sparse regions have various star formation histories, while galaxies in the dense regions are found to have shorter SFR time

  13. Spacewatch Observations of Near-Earth Objects

    NASA Astrophysics Data System (ADS)

    McMillan, Robert S.; Larsen, Jeffrey A.; Bressi, Terrence H.; Scotti, James V.; Mastaler, Ronald A.; Tubbiolo, Andrew F.

    2015-08-01

    Spacewatch specializes in followup of NEOs of high priority while they are faint, producing an annual average of ~8500 lines of astrometry of ~1,000 different NEOs. We contribute to the removal of half of the objects that were retired from impact risk lists. Our observations at elongations as small as 46 deg support followup of hazardous NEOs and NEOs discovered by the NEOWISE spacecraft. Per year we observe about 35 radar targets, 50 NEOs that were measured by NEOWISE, and 100 potential rendezvous destinations. In the last 3 years we have observed 50% of all NEOs observed in that time and 54% of all PHAs observed in that time. We lead in followup of provisionally designated PHAs while faint (V>= 22); contributing 41% of all such observations. With the Steward Obs. 0.9-m telescope, site code 691, we survey with a mosaic of CCDs near opposition and at low elongation in the east. Coverage is 1400 sq. deg per lunation; V mag limit ~20.5-21.7. The 12 yrs of uniform surveying will go live on the web in 2015 to support incidental astrometry & precoveries of NEOs. On the Spacewatch 1.8-m telescope, site code 291, the FOV = 20x20 arcmin and the pixel scale = 0.6 arcsec/pixel. V mag limit=23 and the astrometric residuals are +/-0.3 arcsec. Our output with the Bok 2.3-m & Mayall 4-m telescopes from 2010-2014 was 1316 lines of astrometry on 207 different NEOs, including 84 different PHAs. 343 observations were made of PHAs with V>=22. Our average calendar span extension on large PHAs is 6 mo, 2x longer than the next most effective observing station. We extend the span of calendar time coverage on PHAs an average of 3.8x. For 38 of 72 PHAs we added another observed opposition. With the Bok & Mayall we reduce uncertainties of orbital elements an average of a factor of 6 and the uncertainty of the time of perihelion passage an average of a factor of 19 (G. Williams 2014 private communication). We gratefully acknowledge NASA's NEO Observation Program, The IAU's Minor Planet

  14. HUBBLE SNAPSHOT CAPTURES LIFE CYCLE OF STARS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this stunning picture of the giant galactic nebula NGC 3603, the crisp resolution of NASA's Hubble Space Telescope captures various stages of the life cycle of stars in one single view. To the upper right of center is the evolved blue supergiant called Sher 25. The star has a unique circumstellar ring of glowing gas that is a galactic twin to the famous ring around the supernova 1987A. The grayish-bluish color of the ring and the bipolar outflows (blobs to the upper right and lower left of the star) indicates the presence of processed (chemically enriched) material. Near the center of the view is a so-called starburst cluster dominated by young, hot Wolf-Rayet stars and early O-type stars. A torrent of ionizing radiation and fast stellar winds from these massive stars has blown a large cavity around the cluster. The most spectacular evidence for the interaction of ionizing radiation with cold molecular-hydrogen cloud material are the giant gaseous pillars to the right and lower left of the cluster. These pillars are sculptured by the same physical processes as the famous pillars Hubble photographed in the M16 Eagle Nebula. Dark clouds at the upper right are so-called Bok globules, which are probably in an earlier stage of star formation. To the lower left of the cluster are two compact, tadpole-shaped emission nebulae. Similar structures were found by Hubble in Orion, and have been interpreted as gas and dust evaporation from possibly protoplanetary disks (proplyds). The 'proplyds' in NGC 3603 are 5 to 10 times larger in size and correspondingly also more massive. This single view nicely illustrates the entire stellar life cycle of stars, starting with the Bok globules and giant gaseous pillars, followed by circumstellar disks, and progressing to evolved massive stars in the young starburst cluster. The blue supergiant with its ring and bipolar outflow marks the end of the life cycle. The color difference between the supergiant's bipolar outflow and the diffuse

  15. KEPLER OBSERVATIONS OF THREE PRE-LAUNCH EXOPLANET CANDIDATES: DISCOVERY OF TWO ECLIPSING BINARIES AND A NEW EXOPLANET

    SciTech Connect

    Howell, Steve B.; Rowe, Jason F.; Bryson, Stephen T.; Sherry, William; Von Braun, Kaspar; Ciardi, David R.; Feldmeier, John J.; Horch, Elliott; Van Belle, Gerard T.

    2010-12-20

    Three transiting exoplanet candidate stars were discovered in a ground-based photometric survey prior to the launch of NASA's Kepler mission. Kepler observations of them were obtained during Quarter 1 of the Kepler mission. All three stars are faint by radial velocity follow-up standards, so we have examined these candidates with regard to eliminating false positives and providing high confidence exoplanet selection. We present a first attempt to exclude false positives for this set of faint stars without high-resolution radial velocity analysis. This method of exoplanet confirmation will form a large part of the Kepler mission follow-up for Jupiter-sized exoplanet candidates orbiting faint stars. Using the Kepler light curves and pixel data, as well as medium-resolution reconnaissance spectroscopy and speckle imaging, we find that two of our candidates are binary stars. One consists of a late-F star with an early M companion, while the other is a K0 star plus a late M-dwarf/brown dwarf in a 19 day elliptical orbit. The third candidate (BOKS-1) is an r = 15 G8V star hosting a newly discovered exoplanet with a radius of 1.12 R{sub Jupiter} in a 3.9 day orbit.

  16. Near Infrared Spectroscopy of Active Galactic Nuclei Using FSpec

    NASA Astrophysics Data System (ADS)

    Frechem, Joshua; Pessev, Peter

    2015-01-01

    Using data from the 2.3 meter Bok telescope on Kitt Peak and the FRANKENSpec spectrograph, we aim to investigate the circumnuclear region of over twenty active galaxies in the J, H, and K passbands in order to obtain high signal to noise spectra with reasonable investment of observing time. The sample is selected to cover a wide range of AGN types of activity in luminous nearby galaxies. The primary goal of this project was to sort and process the 9,000+ spectra, including dark subtraction, flat fielding, and creation of and application of bad pixel masks. The 2-D spectra were processed to a 1-D spectra and wavelength calibrated to reveal the exact wavelength of each peak in the spectra. Using standard stars is of utmost importance so the atmospheric lines can be corrected for and the data can be used for precise analysis. With the reduced and calibrated spectra, we measure the Paschen α, β, and γ Hydrogen lines, the Brackett γ Hydrogen line and the FeII line in the near infrared emitted from the circumnuclear regions of the galaxies. These data unveil details of what the environment is like in the area surrounding the supermassive black holes that are found in the heart of each of these galaxies.

  17. Crimson Tide: The Harvard Books on Astronomy

    NASA Astrophysics Data System (ADS)

    Lindner, R. P.

    2001-12-01

    The Harvard Books on Astronomy, a series of crimson clad, fully illustrated volumes, cornered, for more than a generation, the market of readers interested in astronomy. A large number of astronomers owe their first serious initiation to the literature of astronomy to these books. Their style, presentation, design, and tone marked a clear departure from the inherited traditions in the field. Each summed up a field, awarded points for merit, and staked out paths for future study. No doubt each of the more mature readers of this abstract has his or her favorite volume, and even his or her own favorite edition of a particular volume. How the volumes evolved and what happened to the series with Harlow Shapley's retirement are not only questions in the history of the book but also form a commentary on the standards of scientific writing for the educated public. For this the major evidence comes from the volumes by Shapley himself, Leo Goldberg and Lawrence Aller, and the Boks. This paper discusses the origins of the series, the purpose of the works, the varying successes of the volumes, and the impact they had on the future astronomical community. In part, this is a contribution to the impact of Harlow Shapley upon the wider field and the role of Harvard in the American astronomical community. It is also a meditation upon the ways of recruitment into the field and forming ways of looking at research problems.

  18. Pifithrin-α ameliorates resveratrol-induced two-cell block in mouse preimplantation embryos in vitro.

    PubMed

    Jeong, Jae-Kyo; Kang, Min-Hee; Gurunathan, Sangiliyandi; Cho, Ssang-Goo; Park, Chankyu; Park, Jin-Ki; Kim, Jin-Hoi

    2015-03-15

    Treatment with resveratrol at concentrations greater than 0.5 μmol/L resulted in the arrest of mouse embryo development at the two-cell stage. Resveratrol-induced cytotoxicity was investigated in embryos by evaluating morphologic features by using the bromodeoxyuridine assay and acridine orange and ethidium bromide double staining. Resveratrol was found to significantly increase the expressions of p53, p21, Atf3, smac/Diablo, Bax, Bak1, Bok, and Noxa mRNA in the embryos, whereas Cullin 3 and Cdk1 expressions were decreased. Furthermore, active p53 positive signal in embryos arrested at the two-cell stage was localized in the nucleus, whereas no active p53 signal was observed in control embryos. Pretreatment with pifithrin-α, a p53 inhibitor, downregulated active p53 in two-cell embryo nuclei and ameliorated approximately 50% of the embryonic developmental defect caused by resveratrol. The findings of the present study, therefore, suggest that pifithrin-α could be used as an effective cytoprotective agent against a reproductive toxin such as resveratrol. PMID:25542456

  19. Territorial and land-use rights perspectives on human-chimpanzee-elephant coexistence in West Africa (Guinea, Guinea-Bissau, Senegal, nineteenth to twenty-first centuries).

    PubMed

    Leblan, Vincent

    2016-07-01

    The first part of this article compares the distribution of chimpanzee and elephant populations in reaction to human territorial dynamics of West African trade in parts of nineteenth century Guinea, Guinea-Bissau and Senegal. It answers for this specific region the question of whether present-day situations of close chimpanzee-human spatial proximity are stable or only temporary phenomena in long-term processes of environmental change, and shows that conservation policies centred on either of these two "flagship" species carry radically different ecological, political and territorial implications. The second part shifts to local-level perspectives on human-chimpanzee relationships, emphasizing the land rights contentions and misunderstandings created by the implementation of protected areas at Bossou and in the Boké region of Guinea. These case studies help to look at acts of resistance and local interpretations of primate conservation policies as opportunities to reconsider what is being protected, for what purpose, as whose heritage, and to move towards new and more legitimate opportunities for the implementation of conservation policies. PMID:27038218

  20. New Herbig-Haro objects in star-forming regions

    NASA Technical Reports Server (NTRS)

    Reipurth, BO; Graham, J. A.

    1988-01-01

    A list of 25 new Herbig-Haro objects, HH 58 to HH 82, in the Orion molecular clouds and in southern molecular cloud complexes has been compiled. CCD images in the S II 6717, 6731 forbidden lines are presented for the objects, together with a few spectra and some IR observations. The individual objects and, when identified, their energy sources are discussed. HH 65 is located in the red lobe of the bipolar outflow associated with the highly variable reflection nebula Re 50. HH 67 is a 22-arcsec long sinusoidal jet. HH 68/69 consists of a long, linear chain of four HH knots. HH 72 emerges from a 120-solar luminosity IRAS source embedded in a Bok globule. HH 79 is the first HH object discovered in the Ophiuchus clouds. HH 80/81 in Sagittarius are among the brightest HH objects known, have complex velocities, high excitation conditions and emerge from a 6000-solar luminosity young B-star. HH 82 is associated with the bright variable star S Coronae Australis.

  1. Near-Infrared and Optical colors of Trans-Neptunian Objects and Centaurs from Ground-Based Observations in Support of Spitzer Observations

    NASA Astrophysics Data System (ADS)

    Lejoly, Cassandra; Mommert, Michael; Trilling, David; Pinilla-Alonso, Noemi; Emery, Josh; Melton, Chad; McCarthy, Don; Kulesa, Craig

    2015-11-01

    Trans-Neptunian objects and Centaurs are small icy bodies located beyond the orbit of Neptune and between the orbits of Neptune and Jupiter, respectively. These objects are composed of organic material, of silicate minerals and of different ices, including H2O, CH4, N2 and CH3OH. Determining the composition of such object usually requires spectroscopic measurements on large telescopes. However, we can constrain the compositions of these objects by measuring their near-infrared colors that -- in combination with existing data from the Spitzer Space Telescope -- can indicate surface composition.. We will present near-infrared magnitudes and colors of at least 24 trans-Neptunian objects and 3 Centaurs obtained in ground-based observations. We observed with Gemini, UKIRT, and the 90" Bok Telescope on Kitt Peak between 2011 and 2015. The combination of our data with existing Spitzer Space Telescope data enables us to identify spectral slope up to 4.5 μm and provides rough information on spectral bands, which are important clues on the surface composition of our targets. We will present preliminary results on the compositional analysis for select targets. This work was supported by the Spitzer Science Center and NASA's Planetary Astronomy program.

  2. A deep proper motion catalog within the Sloan digital sky survey footprint

    SciTech Connect

    Munn, Jeffrey A.; Harris, Hugh C.; Tilleman, Trudy M.; Hippel, Ted von; Kilic, Mukremin; Liebert, James W.; Williams, Kurtis A.; DeGenarro, Steven; Jeffery, Elizabeth E-mail: hch@nofs.navy.mil E-mail: ted.vonhippel@erau.edu E-mail: jamesliebert@gmail.com E-mail: studiofortytwo@yahoo.com

    2014-12-01

    A new proper motion catalog is presented, combining the Sloan Digital Sky Survey (SDSS) with second epoch observations in the r band within a portion of the SDSS imaging footprint. The new observations were obtained with the 90prime camera on the Steward Observatory Bok 90 inch telescope, and the Array Camera on the U.S. Naval Observatory, Flagstaff Station, 1.3 m telescope. The catalog covers 1098 square degrees to r = 22.0, an additional 1521 square degrees to r = 20.9, plus a further 488 square degrees of lesser quality data. Statistical errors in the proper motions range from 5 mas year{sup −1} at the bright end to 15 mas year{sup −1} at the faint end, for a typical epoch difference of six years. Systematic errors are estimated to be roughly 1 mas year{sup −1} for the Array Camera data, and as much as 2–4 mas year{sup −1} for the 90prime data (though typically less). The catalog also includes a second epoch of r band photometry.

  3. Screening for beneficial effects of oral intake of sweet corn by DNA microarray analysis.

    PubMed

    Tokuji, Yoshihiko; Akiyama, Kyoko; Yunoki, Keita; Kinoshita, Mikio; Sasaki, Keiko; Kobayashi, Hitoshi; Wada, Masahiro; Ohnishi, Masao

    2009-09-01

    To identify novel functions of the oral intake of sweet corn, we performed DNA microarray analysis of the livers of sweet corn-fed mice. Functional annotation clustering 1600 genes with expression levels that were affected (more than 1.5-fold change) by dietary sweet corn indicated that both cell proliferation and programmed cell death were modulated by sweet corn intake. In the Wnt signaling pathway, which is involved in cell proliferation, the levels of Jun and beta-catenin expression were downregulated by dietary sweet corn. The mRNA levels of Rb and p53, negative regulators of the cell cycle, were increased in mice fed with sweet corn. Dietary corn upregulated expression levels of genes that regulate apoptosis positively (for example, BOK, BID, CASP4). These results suggested that sweet corn is a valuable food for suppressing cancer. Oral administration of sweet corn inhibited tumor growth (36.6% reduce in tumor weight, P < 0.05) in mice inoculated with Ehrlich tumor cells. PMID:19895470

  4. A Resource for the Transcriptional Signature of Bona Fide Trophoblast Stem Cells and Analysis of Their Embryonic Persistence

    PubMed Central

    Pfeifer, Dietmar; Arnold, Sebastian J.

    2015-01-01

    Trophoblast stem cells (TSCs) represent the multipotent progenitors that give rise to the different cells of the embryonic portion of the placenta. Here, we analysed the expression of key TSC transcription factors Cdx2, Eomes, and Elf5 in the early developing placenta of mouse embryos and in cultured TSCs and reveal surprising heterogeneity in protein levels. We analysed persistence of TSCs in the early placenta and find that TSCs remain in the chorionic hinge until E9.5 and are lost shortly afterwards. To define the transcriptional signature of bona fide TSCs, we used inducible gain- and loss-of-function alleles of Eomes or Cdx2, and EomesGFP, to manipulate and monitor the core maintenance factors of TSCs, followed by genome-wide expression profiling. Combinatorial analysis of resulting expression profiles allowed for defining novel TSC marker genes that might functionally contribute to the maintenance of the TSC state. Analyses by qRT-PCR and in situ hybridisation validated novel TSC- and chorion-specific marker genes, such as Bok/Mtd, Cldn26, Duox2, Duoxa2, Nr0b1, and Sox21. Thus, these expression data provide a valuable resource for the transcriptional signature of bona fide and early differentiating TSCs and may contribute to an increased understanding of the transcriptional circuitries that maintain and/or establish stemness of TSCs. PMID:26783396

  5. Expression and Critical Role of Interleukin Enhancer Binding Factor 2 in Hepatocellular Carcinoma.

    PubMed

    Cheng, Shaobing; Jiang, Xu; Ding, Chaofeng; Du, Chengli; Owusu-Ansah, Kwabena Gyabaah; Weng, Xiaoyu; Hu, Wendi; Peng, Chuanhui; Lv, Zhen; Tong, Rongliang; Xiao, Heng; Xie, Haiyang; Zhou, Lin; Wu, Jian; Zheng, Shusen

    2016-01-01

    Interleukin enhancer binding factor 2 (ILF2), a transcription factor, regulates cell growth by inhibiting the stabilization of mRNA. Currently, its role has gained recognition as a factor in the tumorigenic process. However, until now, little has been known about the detailed role ILF2 plays in hepatocellular carcinoma (HCC). In this study, we investigated the expression levels of ILF2 in HCC tissue with Western blot and immunohistochemical assays. To examine the effect of ILF2 on liver cancer cell growth and apoptosis, small interfering RNAs (siRNAs) targeting ILF2 were recombined to create lentiviral overexpression vectors. Our results showed higher expression levels of ILF2 mRNA and ILF2 protein in HCC tissue compared with matched peritumoral tissue. Expression of ILF2 may regulate cell growth and apoptosis in liver cancer cells via regulation of B-cell lymphoma 2 (Bcl-2), Bcl-2 related ovarian killer (Bok), Bcl-2-associated X protein (BAX), and cellular inhibitor of apoptosis 1 (cIAP1). Moreover, we inoculated nude mice with liver cancer cells to investigate the effect of ILF2 on tumorigenesis in vivo. As expected, a rapid growth was observed in cancer cells inoculated with a lentiviral vector coding Flag-ILF2 (Lenti-ILF2) compared with the control cells. Hence, these results promote a better understanding of ILF2's potential role as a therapeutic target in HCC. PMID:27556459

  6. Insecticide susceptibility of three species of cutworm (Lepidoptera: Noctuidae) pests of grapes.

    PubMed

    Smirle, Michael J; Zurowski, Cheryl L; Lowery, D Thomas; Mostafa, Ayman M

    2013-10-01

    Climbing cutworms in the genus Abagrotis are economically important pests of grapes in the Okanagan Valley of British Columbia (BC). Grapes are recently introduced into many areas of the region, and the association between crop and pest is new and still evolving. This has led to limited information being available on pest management strategies, including the evaluation of chemical controls compatible with local production practices. Few insecticides are currently registered in Canada for cutworm control on grapes, and our study was initiated to provide information on the efficacy of potential control materials. We were also interested in the relative susceptibilities of the three most common cutworm species attacking grape buds in BC--Abagrotis orbis (Grote), Abagrotis reedi Buckett, and Abagrotis nefascia (Smith). Dose-response bioassays with nine insecticides were conducted on neonate larvae using Bok Choy leaf disks, and on fourth-instar larvae using diet incorporation. There were considerable differences in the toxicity of insecticides within species for neonates and fourth instars. For some materials, the relative toxicity to neonates and fourth instars were not correlated. Response to insecticides among the three species showed variation as well, and correct identification of the species complex present in individual locations is important in choosing the best available control material. PMID:24224256

  7. The effectiveness of spent coffee grounds and its biochar on the amelioration of heavy metals-contaminated water and soil using chemical and biological assessments.

    PubMed

    Kim, Min-Suk; Min, Hyun-Gi; Koo, Namin; Park, Jeongsik; Lee, Sang-Hwan; Bak, Gwan-In; Kim, Jeong-Gyu

    2014-12-15

    Spent coffee grounds (SCG) and charred spent coffee grounds (SCG-char) have been widely used to adsorb or to amend heavy metals that contaminate water or soil and their success is usually assessed by chemical analysis. In this work, the effects of SCG and SCG-char on metal-contaminated water and soil were evaluated using chemical and biological assessments; a phytotoxicity test using bok choy (Brassica campestris L. ssp. chinensis Jusl.) was conducted for the biological assessment. When SCG and SCG-char were applied to acid mine drainage, the heavy metal concentrations were decreased and the pH was increased. However, for SCG, the phytotoxicity increased because a massive amount of dissolved organic carbon was released from SCG. In contrast, SCG-char did not exhibit this phenomenon because any easily released organic matter was removed during pyrolysis. While the bioavailable heavy metal content decreased in soils treated with SCG or SCG-char, the phytotoxicity only rose after SCG treatment. According to our statistical methodology, bioavailable Pb, Cu and As, as well as the electrical conductivity representing an increase in organic content, affected the phytotoxicity of soil. Therefore, applying SCG during environment remediation requires careful biological assessments and evaluations of the efficiency of this remediation technology. PMID:25242543

  8. Growth inhibition in Chinese cabbage (Brassica rapa var. chinensis) growth exposed to di-n-butyl phthalate.

    PubMed

    Liao, Chien-Sen; Yen, Jui-Hung; Wang, Yei-Shung

    2009-04-30

    The toxicity and effects of di-n-butyl phthalate (DBP), an endocrine disruptor, on the growth of Chinese cabbage (Brassica rapa var. chinensis) were studied. Etiolation occurred on leaves of Chinese cabbage plant treated with 50mg/L of DBP for 42 d. DBP even below 1mg/L had a significant effect on the concentration of chlorophyll in Chinese cabbage and the biomass showed a severe decrease under treatment with more than 30 mg/L of DBP. At a concentration below 1mg/L of DBP, no significant difference in accumulation was found, but treatments with concentration exceeding 10, 30, 50 and 100mg/L all resulted in significant accumulation of DBP. Six protein spots extracted from leaf tissue of DBP-treated Chinese cabbage displaying a differential expression are shown in 2-DE maps. According to proteome level studies, three protein spots were found to increase and were identified, respectively, as acyl-[acyl-carrier-protein] desaturase (acyl-ACP desaturase), root phototropism protein 3 (RPT3) and ferredoxin-nitrite reductase (Fd-NiR). The other three protein spots were found to decrease and were identified respectively as dihydroflavonol-4-reductase (DFR), aminoacyl-tRNA synthetase (aaRS) and ATP synthase subunit beta. The key finding is that the other closely related plant, Bok choy (Brassica rapa subsp. chinensis), the subspecies of Chinese cabbage, respond differently to the same chemicals. PMID:18678443

  9. A New Look at Stellar Outflows: Spitzer Observations of the HH 46/47 System

    NASA Technical Reports Server (NTRS)

    Noriega-Crespo, Alberto; Morris, Patrick; Marleau, Francine R.; Carey, Sean; Boogert, Adwin; van Dishoeck, Ewine; Evans, Neal J., II; Keene, Jocelyn; Muzerolle, James; Stapelfeldt, Karl; Pontoppidan, Klaus; Lowrance, Patrick; Allen, Lori; Bourke, Tyler L.

    2004-01-01

    We present the Early Release Observations of the HH 46/47 system and HH 46 IRS 1 source, taken with the three instruments aboard the Spitzer Space Telescope. The optically invisible southwest lobe, driven by the HH 47C bow shock, is revealed in full detail by the Infrared Array Camera (IRAC) images and displays a 'loop'-like morphology. Both of the mid-infrared outflow lobes are narrower than those of CO flow. We believe that the combination of emission by H2 rotational lines [S(11)-S(4)] and some atomic lines, which fall within the IRAC passbands, are responsible for the bulk of the observed emission, although contributions from the 3.3, 6.2, and 7.7 micron polycyclic aromatic hydrocarbon emission bands cannot be ruled out. Weak spectral features corresponding to these emitters are present in the Infrared Spectrograph spectrum of the HH 47A bow shock. The spectrum of HH 46 IRS 1 shows remarkable similarities to those of high-mass protostars, which include the presence of H2O, CO2, CH4, and possibly NH3, CH3OH, and ices. The high ice abundances and the lack of signs of thermal processing indicate that these ices in the envelope are well shielded from the powerful outflow and its cavity. Emission from the Bok globule at 24 micron is detected and displays a similar structure to that observed at 8 micron.

  10. Preliminary Results from a Search for a Nebula in the Vicinity of Sirius

    NASA Astrophysics Data System (ADS)

    Mutz, Steven B.; Wyckoff, Susan

    1992-12-01

    Ptolemy, Seneca, and several Babylonian and mediaeval texts have described Sirius (now A1V for the visible component) as a red star (Gry and Bonnet-Bidaud 1990, Schlosser and Bergman 1985). If true, then the present color of Sirius would be very difficult to explain in terms of current theories of stellar evolution. A possible explanation is that Sirius was eclipsed by a small, dark nebula such as a Bok globule (see Gry and Bonnet-Bidaud 1990). To search for such an object J, H, K, and CO (near 2.4 mu ) imaging of the stellar field near Sirius' apparent postion of 2000 years ago was performed using the University of Arizona's 256x256 IR array on their 61-inch Mt Bigelow telescope. Preliminary (J-H) vs. (H-K) diagrams indicate the presence of color excesses in the area of study (following the methods of Jones et al. 1980, 1984). Examination of the Palomar Sky Survey plates for the region of interest shows several areas where the stellar number density is more than 3 sigma smaller than the average stellar density for that area of the sky. Also, the stellar density for these depleted regions is higher on the red Palomar plate than the number density of the regions on the blue plate, suggesting a redder stellar population in these regions, which may be due to the presence of intervening material.

  11. How to Become a Star

    NASA Astrophysics Data System (ADS)

    2001-01-01

    ESO Telescopes Provide Most Detailed View Ever Into a Dark Cloud Summary How do stars like our Sun come into being? Which fundamental processes are responsible for transforming a dark and diffuse interstellar cloud of gas and dust into a much denser, shining object? Astronomers have just taken an important step towards answering this fundamental question. Based on the most detailed study ever made of the internal structure of a small interstellar cloud, three scientists from ESO and the USA [1] have found that it is apparently on the verge of becoming unstable - and thus in the stage immediately preceding a dramatic collapse into a dense and hot, low-mass star. Interestingly, the current structure of this cloud, a "Bok globule" known as Barnard 68 (B68) [2], is governed by the same basic physics as is that of a star. The cloud is obviously in a temporary state of near-equilibrium, where the inward force of gravity caused by its mass more or less balances that of the outward pressure due to its temperature. But this situation may not last long. The astronomers believe that this particular cloud, together with some others in the same galactic neighbourhood, constitute the few resistent remains of a much larger cloud that has disappeared due to the influence of strong stellar winds and ultraviolet radiation from young and heavy stars as well as supernova explosions. The new and unique insight into the pre-collapse phase of the complicated process of stellar birth is based on observations made with ESO telescopes at the La Silla and Paranal observatories in Chile. PR Photo 02a/01 : The Bok Globule B68 , as seen in visual light. PR Photo 02b/01 : Looking through the Bok Globule B68 . PR Photo 02c/01 : A comparison of the visual and infrared views of the Bok Globule B68 . From Dark Clouds to Stars Astronomers have known for some time that stars like our Sun are formed from interstellar clouds of gas and dust. When they contract, the interior temperature rises. If the

  12. The Supernova Spectropolarimetry Project: Results from Multi-Epoch Observations of the Type IIb SN 2011dh

    NASA Astrophysics Data System (ADS)

    Bilinski, Christopher; Williams, G. G.; Smith, P. S.; Smith, N.; Milne, P.; Hoffman, J. L.; Huk, L. N.; Leonard, D. C.; Dessart, L.

    2014-01-01

    The Supernova Spectropolarimetry Project is a recently formed collaboration between observers and theorists that focuses on decoding the complex, time-dependent spectropolarimetric behavior of supernovae (SNe) of all types. Using the CCD Imaging/Spectropolarimeter (SPOL) at the 61" Kuiper, the 90" Bok, and the 6.5-m MMT telescopes, we obtain multi-epoch observations of each target, aiming to construct the most comprehensive survey to date of supernovae in polarized light. Preliminary results from the SNSPOL project provide support for the increasingly popular hypothesis that many supernovae are aspherical explosion events. Thus far, we have observed 27 different SNe, many over multiple epochs, over the course of the last three years. While the history and evolution of these events is often studied with photometric and spectroscopic information, most supernovae are not studied with the combined advantage that spectropolarimetric data provides. The use of polarimetry allows us to probe the extent of the asphericity of the explosions while the use of spectroscopy allows us to characterize this asphericity across a variety of chemical species individually and as a function of velocity. Modern 3-D model simulations favor an explosion mechanism that is often inherently asymmetric in nature. Here, we showcase some of our initial results for the nearby type-IIb SN 2011dh that demonstrate the unique information that spectropolarimetric observations provide.

  13. The Supernova Spectropolarimetry Project: Evolution of Asymmetries in the Very Luminous Type Ib SN 2012au

    NASA Astrophysics Data System (ADS)

    Hoffman, Jennifer L.; Smith, N.; Bilinski, C.; Dessart, L.; Huk, L. N.; Leonard, D. C.; Milne, P.; Smith, P. S.; Williams, G.

    2014-01-01

    The Supernova Spectropolarimetry Project is a recently formed collaboration between observers and theorists that focuses on decoding the complex, time-dependent spectropolarimetric behavior of supernovae (SNe) of all types. Using the CCD Imaging/Spectropolarimeter (SPOL) at the 61" Kuiper, the 90" Bok, and the 6.5-m MMT telescopes, we obtain multi-epoch observations of each target, aiming to construct the most comprehensive survey to date of supernovae in polarized light. In this poster we present the results of 6 epochs of spectropolarimetric observations of the Type Ib SN 2012au spanning the first 315 days of its evolution. This supernova was a very energetic, luminous, and slow-evolving event that may represent an intermediate case between normal core-collapse SNe and the enigmatic superluminous SNe (SLSNe). Strong, time-variable line polarization signatures, particularly in the He I λ5876 line, support previous hypotheses of an asymmetric explosion and allow us to trace detailed structures within the supernova ejecta as they change over time. We compare the spectropolarimetric evolution of SN 2012au with that of other objects in our data set and discuss its connections with other SNe Ib/c and SLSNe.

  14. The Supernova Spectropolarimetry Project: Results from Multi-Epoch Observations of the Type IIn SN 2010jl

    NASA Astrophysics Data System (ADS)

    Williams, George G.; Dessart, L.; Hoffman, J. L.; Huk, L. N.; Leonard, D. C.; Milne, P.; Smith, N.; Smith, P. S.

    2014-01-01

    The Supernova Spectropolarimetry Project is a recently formed collaboration between observers and theorists that focuses on decoding the complex, time-dependent spectropolarimetric behavior of supernovae (SNe) of all types. Using the CCD Imaging/Spectropolarimeter (SPOL) at the 61" Kuiper, the 90" Bok, and the 6.5-m MMT telescopes, we obtain multi-epoch observations of each target, aiming to construct the most comprehensive survey to date of supernovae in polarized light. We present results from the multi-epoch spectropolarimetric observations of the SN 2010jl. This type IIn supernova in UGC 5189A remained bright for an unusually long time allowing us to obtain 11 epochs of data over the course of 15 months. We find significant polarization in the continuum and variations in polarization across the Balmer and HeI lines. The measured polarized continuum decreased steadily over the 15 months of observations. This evolution allowed us to make a solid estimate of the interstellar polarization component thereby revealing the intrinsic supernova polarization. The polarization provides us with detailed information about the aspherical morphology of the explosion and the properties of the progenitor’s pre-explosion mass loss.

  15. The Supernova Spectropolarimetry Project: Probing the Evolution of Asymmetries in Supernovae

    NASA Astrophysics Data System (ADS)

    Hoffman, Jennifer; Williams, G. G.; Bilinski, C.; Dessart, L.; Huk, L. N.; Leonard, D. C.; Mauerhan, J.; Smith, N.; Smith, P. S.

    2014-07-01

    Nearly all supernovae possess spectropolarimetric signatures that indicate the presence of aspherical morphologies in the ejecta and/or surrounding circumstellar material. Interpreting the time variations of these spectropolarimetric signatures can yield unprecedentedly detailed information about supernova explosion mechanisms, the physical processes that shape the ejecta's density and velocity distributions, and the properties of the progenitor star.The Supernova Spectropolarimetry Project (SNSPOL) is a collaboration between observers and theorists that focuses on understanding the time-dependent spectropolarimetric behavior of supernovae. Using the CCD Imaging/Spectropolarimeter (SPOL) at the 61" Kuiper, the 90" Bok, and the 6.5-m MMT telescopes, we have obtained multi-epoch observations of over 50 supernovae of various types. I will present observational results from this project and discuss ongoing modeling efforts. Initial analysis reveals complex variable line polarization signatures that probe the distributions of different chemical species and thereby trace the detailed structure of the ejecta as these supernovae evolve. Our continuing observations will form the most comprehensive survey to date of supernovae in polarized light, allowing us to illuminate previously obscured relationships among subtypes, constrain progenitor properties, and build a more complete picture of the supernova population as a whole.

  16. VISITORS FROM THE HALO: 11 Gyr OLD WHITE DWARFS IN THE SOLAR NEIGHBORHOOD

    SciTech Connect

    Kilic, Mukremin; Brown, Warren R.; McLeod, B.; Munn, Jeffrey A.; Harris, Hugh C.; Williams, Kurtis A.; DeGennaro, Steven; Kowalski, P. M.; Von Hippel, Ted; Jeffery, Elizabeth J.

    2010-05-20

    We report the discovery of three nearby old halo white dwarf (WD) candidates in the Sloan Digital Sky Survey (SDSS), including two stars in a common proper motion binary system. These candidates are selected from our 2800deg{sup 2} proper motion survey on the Bok and U.S. Naval Observatory Flagstaff Station 1.3 m telescopes, and they display proper motions of 0.''4-0.''5 yr{sup -1}. Follow-up MMT spectroscopy and near-infrared photometry demonstrate that all three objects are hydrogen-dominated atmosphere WDs with T {sub eff} {approx} 3700-4100 K. For average mass WDs, these temperature estimates correspond to cooling ages of 9-10 Gyr, distances of 70-80 pc, and tangential velocities of 140-200 km s{sup -1}. Based on the UVW space velocities, we conclude that they most likely belong to the halo. Furthermore, the combined main-sequence and WD cooling ages are 10-11 Gyr. Along with SDSS J1102+4113, they are the oldest field WDs currently known. These three stars represent only a small fraction of the halo WD candidates in our proper motion survey, and they demonstrate that deep imaging surveys like the Pan-STARRS and Large Synoptic Survey Telescope should find many old thick disk and halo WDs that can be used to constrain the age of the Galactic thick disk and halo.

  17. The Robotic Super-LOTIS Telescope: Results & Future Plans

    NASA Astrophysics Data System (ADS)

    Williams, G. G.; Milne, P. A.; Park, H. S.; Barthelmy, S. D.; Hartmann, D. H.; Updike, A.; Hurley, K.

    2008-05-01

    We provide an overview of the robotic Super-LOTIS (Livermore Optical Transient Imaging System) telescope and present results from gamma-ray burst (GRB) afterglow observations using Super-LOTIS and other Steward Observatory telescopes. The 0.6-m Super-LOTIS telescope is a fully robotic system dedicated to the measurement of prompt and early time optical emission from GRBs. The system began routine operations from its Steward Observatory site atop Kitt Peak in April 2000 and currently operates every clear night. The telescope is instrumented with an optical CCD camera and a four position filter wheel. It is capable of observing Swift Burst Alert Telescope (BAT) error boxes as early or earlier than the Swift UV/Optical Telescope (UVOT). Super-LOTIS complements the UVOT observations by providing early R- and I-band imaging. We also use the suite of Steward Observatory telescopes including the 1.6-m Kuiper, the 2.3-m Bok, the 6.5-m MMT, and the 8.4-m Large Binocular Telescope to perform follow-up optical and near infrared observations of GRB afterglows. These follow-up observations have traditionally required human intervention but we are currently working to automate the 1.6-m Kuiper telescope to minimize its response time.

  18. South Galactic Cap u-band Sky Survey (SCUSS): Project Overview

    NASA Astrophysics Data System (ADS)

    Zhou, Xu; Fan, Xiao-Hui; Fan, Zhou; He, Bo-Liang; Jiang, Lin-Hua; Jiang, Zhao-Ji; Jing, Yi-Peng; Lesser, Michael; Ma, Jun; Nie, Jun-Dan; Shen, Shi-Yin; Wang, Jia-Li; Wu, Zhen-Yu; Zhang, Tian-Meng; Zhou, Zhi-Min; Zou, Hu

    2016-04-01

    The South Galactic Cap u-band Sky Survey (SCUSS) was established in 2009 in order to provide a photometric input catalog for target selection of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) project. SCUSS is an international cooperative project between National Astronomical Observatories, Chinese Academy of Sciences, and Steward Observatory at the University of Arizona, using the 90 inch (2.3m) Bok telescope on Kitt Peak. The telescope is equipped with a prime focus camera that is composed of a mosaic of four 4096 × 4096 CCDs and has a field of view of about 1 deg2. From 2009 to 2013, SCUSS performed a sky survey of an approximately 5000 deg2 field of the South Galactic Cap in u band, including the Galactic anticenter area and the SDSS-IV extended imaging area. The limiting magnitude of SCUSS is deeper than 23 mag (at a signal-to-noise ratio of 5). In this paper, we briefly describe the goals of this project, method of observations and data reduction, and we also introduce current and potential scientific activities related to the SCUSS project.

  19. Near-IR Spectral Variability Of Young Stars: A Multi-year Survey

    NASA Astrophysics Data System (ADS)

    Hawkins, Clint; Eisner, J.; Rudolph, A. L.

    2012-01-01

    T-Tauri type stars exhibit variability across the electromagnetic spectrum, including in the visible and the infrared regions. While spectroscopic variability in the optical range has been previously investigated, variability in the near-IR has not been explored as thoroughly. We have been tracking the spectral variability of about 40 young stars in the near-IR during the past year. Using the 90-inch Bok telescope on Kitt Peak, we observed our sample with FSPEC during four five-night runs, two in 2010 separated by one month and two in 2011, also separated by one month. Here we present spectra for each of these epochs that show emission from the Brackett Gamma (BrG) transition of hydrogen. Changes in the BrG line profile from epoch to epoch are used to constrain the properties of accretion onto our young star targets as a function of time. We acknowledge the NSF for funding under Award No. AST-0847170, a PAARE Grant for the Calfornia-Arizona Minority Partnership for Astronomy Research and Education (CAMPARE).

  20. A New Database of observed SEDs of Nearby Starburst Galaxies from the UV to the FIR

    NASA Astrophysics Data System (ADS)

    Wu, W.; Clayton, G. C.; Gordon, K. D.; Misselt, K. A.; Smith, T. L.

    2000-12-01

    We present a new database of UV to FIR data of about 50 nearby starburst galaxies. The galaxies are selected based upon the availability of IUE data. We have recalibrated the IUE UV spectra for these galaxies by incorporating the most recent improvements in the IUE data calibration. For the spectra in optical range, we include the data from the atlas by Kinney et al. and the results of our own long-slit observations with the Bok telescope (Steward Observatory), complemented by the photometric data from the HST/WFPC2 observations. The NIR data are from the literature, our new observations at CTIO, NASA/IRTF and the Mount Laguana Observatory. In addition, the ISO archive has provided mid-IR spectra for some of the galaxies. The optical to IR data are matched to the IUE aperture. In conjunction with IRAS and ISO FIR fluxes, all these data form a set of observed spectral energy distributions (SEDs) of the nucleus regions of nearby starburst galaxies, which should be useful in studying star formation and dust/gas attenuation in galaxies.

  1. Large Scale Environments Containing Wide Angle Tail Radio Sources

    NASA Astrophysics Data System (ADS)

    Krughoff, K. S.; Batuski, D. J.; Melott, A. L.; Hill, J. M.

    2003-05-01

    Wide angle tail(WAT) radio sources have slightly bent radio lobes. In Abell clusters of galaxies, this bending could be associated with a bulk flow of inter-cluster gas through the cluster containing the WAT. Novikov, et al. (1999) provided evidence that the flow of inter-cluster gas is aligned with the semi-major axis of the local supercluster. This suggests that the preferential bending of WATs may be an indication of mass flow that is a remnant of large-scale structure formation. We have compiled an enlarged sample on which to employ statistical methods in order to strengthen or weaken previous assertions that WATs tend to be bent along supercluster axes. Using the MX spectrometer on the Bok 2.3m telescope, we have observed Abell clusters in regions surrounding 12 clusters containing WAT radio sources, thus enlarging the possible number of regions from the original study, which contained a different set of 12 regions. We present a new WAT-supercluster alignment study based on this enlarged sample of measured cluster neighborhoods. This study has been partially funded by NASA, through the Maine Space Grant Consortium.

  2. Expression and Critical Role of Interleukin Enhancer Binding Factor 2 in Hepatocellular Carcinoma

    PubMed Central

    Cheng, Shaobing; Jiang, Xu; Ding, Chaofeng; Du, Chengli; Owusu-Ansah, Kwabena Gyabaah; Weng, Xiaoyu; Hu, Wendi; Peng, Chuanhui; Lv, Zhen; Tong, Rongliang; Xiao, Heng; Xie, Haiyang; Zhou, Lin; Wu, Jian; Zheng, Shusen

    2016-01-01

    Interleukin enhancer binding factor 2 (ILF2), a transcription factor, regulates cell growth by inhibiting the stabilization of mRNA. Currently, its role has gained recognition as a factor in the tumorigenic process. However, until now, little has been known about the detailed role ILF2 plays in hepatocellular carcinoma (HCC). In this study, we investigated the expression levels of ILF2 in HCC tissue with Western blot and immunohistochemical assays. To examine the effect of ILF2 on liver cancer cell growth and apoptosis, small interfering RNAs (siRNAs) targeting ILF2 were recombined to create lentiviral overexpression vectors. Our results showed higher expression levels of ILF2 mRNA and ILF2 protein in HCC tissue compared with matched peritumoral tissue. Expression of ILF2 may regulate cell growth and apoptosis in liver cancer cells via regulation of B-cell lymphoma 2 (Bcl-2), Bcl-2 related ovarian killer (Bok), Bcl-2-associated X protein (BAX), and cellular inhibitor of apoptosis 1 (cIAP1). Moreover, we inoculated nude mice with liver cancer cells to investigate the effect of ILF2 on tumorigenesis in vivo. As expected, a rapid growth was observed in cancer cells inoculated with a lentiviral vector coding Flag-ILF2 (Lenti-ILF2) compared with the control cells. Hence, these results promote a better understanding of ILF2’s potential role as a therapeutic target in HCC. PMID:27556459

  3. CD metrology for avoiding shrinkage of ArF resist patterns in 100 nm ArF lithography

    NASA Astrophysics Data System (ADS)

    You, Tae-Jun; Bok, Cheol-Kyu; Shin, Ki-Soo

    2002-07-01

    ML 4689-80 CD Metrology for Avoiding Shrinkage of ArF Resist Patterns in 100nm ArF Lithography Tae-Jun You, Cheolkyu Bok, Ki-Soo Shin Hynix Semiconductor, San 136-1 Amiri, Bubal-eub, Ichon-si, Kyongki-do 467-701, Korea We have observed CD(Critical Dimension) shrinkage of acrylate type ArF resist patterns during SEM measurement. CD change was 30% shrinkage for line pattern and 10% expansion for contact hole patterns after 30 times measurement. CD shrinkage was proportion to line pattern size but no relation with LER(Line Edge Roughness). We confirm that CD shrinkage different from resist to resist and SEM measurement condition. CD shrinkage was bigger for acrylate type resist than COMA(Cyclo Olefin Maleic Anhydride) type resist and smaller at lower electron voltage and current conditions. In order to get the improvement of CD shrinkage, we performed electron-beam curing before SEM measurement. Above (see paper for formula) electron-beam dose condition, CD shrinkage improved from 10% to 3%. However, this method caused OPC(Optical Proximity Correction) issue as CD also changed after electron-beam curing. Therefore, we tried to develop a new measurement method instead of applying additional process technique. In this paper, we will describe our CD measurement method, Off-Site measurement technique, for 100nm DRAM lithography. The Off-Site CD measurement repeatability (formula available in paper) was controlled below (see paper).

  4. Far infrared, near infrared, and radio molecular line studies of HFE 2, HFE 3, and FJM 6

    NASA Technical Reports Server (NTRS)

    Fischer, J.; Cassar, L.; Righini-Cohen, G.; Simon, M.

    1979-01-01

    Far-infrared, near-infrared, and radio molecular-line observations of the regions of HFE 2, HFE 3, and FJM 6 are described. At positions of high molecular column density nearest to the reported positions of these sources, their infrared emission cannot be confirmed at upper bounds below those of the original detection. Near-infrared observations of the FJM 6 region (which includes the Bok globule Barnard 361) reveal a number of stellar sources, most of which are behind the molecular cloud and are reddened by it. Visual extinction through B 361 estimated by star counts yields A sub V/N(/C-13/O) = 3.7 + or - 1.6) x 10 to the -16th mag sq cm. The gas temperature and the upper bound on the dust temperature in the FJM 6 region are consistent with cosmic-ray heating of the cloud, while the values of these parameters for the clouds in the HFE 2 and HFE 3 regions do not appear consistent with either cosmic-ray or radiative heating.

  5. A Wavelet Time Series Analysis of Aperiodic Variable Stars in the Kepler Field

    NASA Astrophysics Data System (ADS)

    Arnold, Timothy; Mighell, K.; Howell, S.

    2009-12-01

    The variable sky offers insights into the physical mechanisms of astronomical objects and can be used as a useful tool for many other purposes like the determination of distance with standard candles. Periodic variables were the first to be classified, understood, and used. Many variable but aperiodic light curves are discarded or insufficiently analyzed because of the apparent uselessness of the information contained in these data. Many contemporary projects (e.g. the Large Synoptic Survey Telescope, PanSTARRS, the Kepler mission) aim to map the transient sky, and recently methods of time series analysis have become increasingly advanced. It would be advantageous to discover identifying information in the large number of variable but ostensibly aperiodic light curves. We use a wavelet analysis, based on a weighted projection of time series data on to basis functions, to analyze aperiodic variable stars in the Burrell-Optical-Kepler Survey (BOKS). Using the Weighted Wavelet Z-Transform detailed in Foster 1996, we find that variable but aperiodic stars in our sample offer few characteristic properties that would be useful for further classification. Arnold's research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

  6. A Systems Engineering Approach to Quality Assurance for Aerospace Testing

    NASA Technical Reports Server (NTRS)

    Shepherd, Christena C.

    2015-01-01

    On the surface, it appears that AS91001 has little to say about how to apply a Quality Management System (QMS) to major aerospace test programs (or even smaller ones). It also appears that there is little in the quality engineering Body of Knowledge (BOK)2 that applies to testing, unless it is nondestructive examination (NDE), or some type of lab or bench testing associated with the manufacturing process. However, if one examines: a) how the systems engineering (SE) processes are implemented throughout a test program; and b) how these SE processes can be mapped to the requirements of AS9100, a number of areas for involvement of the quality professional are revealed. What often happens is that quality assurance during a test program is limited to inspections of the test article; what could be considered a manufacturing al fresco approach. This limits the quality professional and is a disservice to the programs and projects, since there are a number of ways that quality can enhance critical processes, and support efforts to improve risk reduction, efficiency and effectiveness.

  7. Wide Integral Field Infrared Spectroscopic Survey of Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Sivanandam, Suresh; Moon, Dae-Sik; Zaritsky, Dennis F.; Chou, Richard; Meyer, Elliot; Ma, Ke; Jarvis, Miranda; Eisner, Joshua A.

    2015-01-01

    We are constructing a novel infrared integral field spectrograph with a large field of view (~50'x20') that will be available on the Kitt Peak 90' Bok telescope this spring. This wide integral field infrared spectrograph (WIFIS) operates over two wavelength ranges, zJ-band (0.9-1.35 microns) and H-band (1.5-1.8 microns), and has moderate spectral resolving power, 3,000 in zJ-band and 2,200 in H-band, respectively. WIFIS' field-of-view is comparable to current optical integral field spectrographs that are carrying out large galaxy surveys, e.g. SAMI, CALIFA, and MaNGA. We are designing a large nearby galaxy survey to complement the data already been taken by these optical integral field spectroscopic surveys. The near-infrared window provides a sensitive probe of the initial mass functions of stellar populations, the OB stellar fractions in massive star forming regions, and the kinematics of and obscured star formation within merging systems. This will be the first large scale infrared integral field spectroscopic survey of nearby galaxies.

  8. Geomorphological context of the basins of Northwestern Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Sautter, Benjamin; Pubellier, Manuel; Menier, David

    2014-05-01

    Geomorphological context of the basins of Northwestern Peninsular Malaysia Benjamin Sautter, Manuel Pubellier, David Menier Department of Petroleum Geosciences, Universiti Teknologi PETRONAS CNRS-UMR 8538, Ecole Normale Supérieure, 24, Rue Lhomond, 75231, Paris Cedex 05, France Petroleum basins of Western Malaysia are poorly known and their formation is controlled by the Tertiary stress variations applied on Mesozoic basement structures. Among these are the Paleozoic-Mesozoic Bentong Raub, Inthanon, and Nan suture zones. By the end of Mesozoic times, the arrival of Indian plate was accompanied by strike slip deformation, accommodated by several Major Faults (Sagaing, Three Pagodas, Mae Ping, Red River, Ranong and Klong Marui Faults). Due to changes in the boundary forces, these areas of weakness (faults) were reactivated during the Tertiary, leading to the opening of basins in most of Sundaland. Within this framework, while most of the Sundaland records stretching of the crust and opening of basins (SCS, Malay, Penyu, Natuna, Mergui) during the Cenozoics, Peninsular Malaysia and the Strait of Malacca are considered to be in tectonic quiescence by most of the authors. We present the geomorphology of the Northwestern Malaysia Peninsula with emphasis on the deformations onshore from the Bentong Raub Suture Zone to the Bok Bak Fault, via the Kinta Valley, and offshore from the Port Klang Graben to the North Penang Graben. By analyzing Digital Elevation Model from ASTER and SRTM data, two main directions of fractures in the granitic plutons are highlighted: NW-SE to W-E sigmoidal faults and N-S to NE-SW linear fractures which seem to cross-cut the others. In the field in the area of the Kinta Valley (Western Belt, NW Peninsular Malaysia), granitic bodies show intense fracturation reflecting several stages of deformation. The granites are generally syntectonic and do not cut fully across the Late Paleozoic platform limestone. Two sets of fractures (NW-SE and NE

  9. Morphological variation, advertisement call, and tadpoles of Bokermannohyla nanuzae (Bokermann, 1973), and taxonomic status of B. feioi (Napoli & Caramaschi, 2004) (Anura, Hylidae, Cophomantini).

    PubMed

    Walker, Marina; Lourenço, Ana Carolina Calijorne; Pimenta, Bruno V S; Nascimento, Luciana Barreto

    2015-01-01

    Bokermannohyla nanuzae (Bokermann & Sazima 1973) and B. feioi (Napoli & Caramaschi 2004) belong to the B. cir-cumdata species group. The type locality of the former is Serra do Cipó, Espinhaço mountain range, and of the latter is Parque Estadual do Ibitipoca, Mantiqueira mountain range, both in Minas Gerais State, Brazil. Differences on dorsal draw-ing pattern of adults, oral disc morphology of tadpoles, and temporal properties of calls were proposed to distinguish these two species. However, several specimens found between the two type localities remain unidentified because diagnostic characters and states occur in all of these populations. Thus, in order to assess these characters variations, we performed an analysis of the morphology and morphometry of adults, vocalization, and morphology of tadpoles. Specimens were divided into three operational taxonomic units (OTUs): B. nanuzae (Serra do Cipó and northwards, Espinhaço mountain range), B. cf. nanuzae (Quadrilátero Ferrífero, Espinhaço mountain range, south of Serra do Cipó), and B. feioi (Serra do Ibitipoca, Mantiqueira mountain range). Drawing patterns of the dorsum and limbs show clinal variation and the three units are morphometrically very similar. Temporal and spectral properties of calls overlap in these three units. The diagnostic differences originally proposed for tadpoles are intrapopulational variations and occur in specimens from all of the locations analyzed. We found that these three units are morphologically indistinguishable. Therefore, we designate Bok-ermannohyla feioi (Napoli & Caramaschi 2004) as a junior synonym of Bokermannohyla nanuzae (Bokermann & Sazima 1973), extending its geographical distribution to the Mantiqueira mountain range. PMID:25947466

  10. A Comparative Study of the Mass Distribution of Extreme-Ultraviolet-selected White Dwarfs

    NASA Astrophysics Data System (ADS)

    Napiwotzki, R.; Green, Paul J.; Saffer, Rex A.

    1999-05-01

    We present new determinations of effective temperature, surface gravity, and masses for a sample of 46 hot DA white dwarfs selected from the Extreme Ultraviolet Explorer (EUVE) and ROSAT Wide Field Camera bright source lists in the course of a near-infrared survey for low-mass companions. Our analysis, based on hydrogen non-LTE model atmospheres, provides a map of LTE correction vectors, which allow a thorough comparison with previous LTE studies. We find that previous studies underestimate both the systematic errors and the observational scatter in the determination of white dwarf parameters obtained via fits to model atmospheres. The structure of very hot or low-mass white dwarfs depends sensitively on their history. To compute white dwarf masses, we thus use theoretical mass-radius relations that take into account the complete evolution from the main sequence. We find a peak mass of our white dwarf sample of 0.59 Msolar, in agreement with the results of previous analyses. However, we do not confirm a trend of peak mass with temperature reported in two previous analyses. Analogous to other EUV-selected samples, we note a lack of low-mass white dwarfs and a large fraction of massive white dwarfs. Only one white dwarf is likely to have a helium core. While the lack of helium white dwarfs in our sample can be easily understood from their high cooling rate, and therefore low detection probability in our temperature range, this is not enough to explain the large fraction of massive white dwarfs. This feature very likely results from a decreased relative sample volume for low-mass white dwarfs caused by interstellar absorption in EUV-selected samples. Spectral observations reported here were obtained with the Multiple Mirror Telescope, a joint facility of the University of Arizona and the Smithsonian Institution, and with the Bok telescope at the Steward Observatory of the University of Arizona.

  11. Astronomy Camp = IYA x 22: 22 Years of International Astronomy Education

    NASA Astrophysics Data System (ADS)

    Hooper, Eric Jon; McCarthy, D. W.; Camp Staff, Astronomy

    2010-01-01

    Do you remember childhood dreams of being an astronomer, or the ravenous desire for ever larger glass and better equipment as an amateur astronomer? What if your child or the person down the street could live that dream for a weekend or a week? The University of Arizona Astronomy Camp continues to substantiate those dreams after more than two decades in existence. Astronomy Camp is an immersion hands-on field experience in astronomy, ranging from two to eight nights, occurring a few times per year. Participants span an age range from elementary students to octogenarians. The three basic offerings include adult camps, a beginning Camp for teenagers, and an advanced teen Camp. Several variants of the basic Camp model have evolved, including an ongoing decade long series of specialized Camps for Girl Scout leaders from across the country, funded by the NIRCam instrument development program for the James Webb Space Telescope. The advanced teen Camp is a microcosm of the entire research arc: the participants propose projects, spend the week collecting and analyzing data using research grade CCDs, infrared arrays, and radio/sub-millimeter telescopes, and finish with a presentation of the results. This past summer the Camps moved to Kitt Peak National Observatory for the first time, providing access to a vast and diverse collection of research instruments, including the 0.9-meter WIYN and 2.3-meter Bok telescopes, the McMath-Pierce Solar Telescope, and the 12-meter ARO radio telescope. Education research into the Camp's impact indicates that reasons for its appeal to youth include a learner-centered and personal approach with a fun attitude toward learning, authentic scientific inquiry led by mentors who are real scientists, a peer group with common interests in science and engineering, and the emotional appeal of spending time on a dark "sky island" devoted to the exploration of nature.

  12. Nuclear export of proteins and drug resistance in cancer

    PubMed Central

    Turner, Joel G.; Dawson, Jana; Sullivan, Daniel M.

    2015-01-01

    The intracellular location of a protein is crucial to its normal functioning in a cell. Cancer cells utilize the normal processes of nuclear-cytoplasmic transport through the nuclear pore complex of a cell to effectively evade anti-neoplastic mechanisms. CRM1-mediated export is increased in various cancers. Proteins that are exported in cancer include tumor-suppressive proteins such as retinoblastoma, APC, p53, BRAC1, FOXO proteins, INI1/hSNF5, galectin-3, Bok, nucleophosmin, RASSF2, Merlin, p21CIP, p27KIP1, N-WASP/FAK, estradiol receptor and Tob, drug targets topoisomerase I and IIα and BCR-ABL, and the molecular chaperone protein Hsp90. Here, we review in detail the current processes and known structures involved in the export of a protein through the nuclear pore complex. We also discuss the export receptor molecule CRM1 and its binding to the leucine-rich nuclear export signal of the cargo protein and the formation of a nuclear export trimer with RanGTP. The therapeutic potential of various CRM1 inhibitors will be addressed, including leptomycin B, ratjadone, KOS-2464, and specific small molecule inhibitors of CRM1, N-azolylacrylate analogs, FOXO export inhibitors, valtrate, acetoxychavicol acetate, CBS9106, and SINE inhibitors. We will also discuss examples of how drug resistance may be reversed by targeting the exported proteins topoisomerase IIα, BCR-ABL, and galectin-3. As effective and less toxic CRM1 export inhibitors become available, they may be used as both single agents and in combination with current chemotherapeutic drugs. We believe that the future development of low-toxicity, small-molecule CRM1 inhibitors may provide a new approach to treating cancer. PMID:22209898

  13. DISCOVERING THE MISSING 2.2 < z < 3 QUASARS BY COMBINING OPTICAL VARIABILITY AND OPTICAL/NEAR-INFRARED COLORS

    SciTech Connect

    Wu Xuebing; Wang Ran; Bian Fuyan; Jiang Linhua; Fan Xiaohui; Schmidt, Kasper B.

    2011-09-15

    The identification of quasars in the redshift range 2.2 < z < 3 is known to be very inefficient because the optical colors of such quasars are indistinguishable from those of stars. Recent studies have proposed using optical variability or near-infrared (near-IR) colors to improve the identification of the missing quasars in this redshift range. Here we present a case study combining both methods. We select a sample of 70 quasar candidates from variables in Sloan Digital Sky Survey (SDSS) Stripe 82, which are non-ultraviolet excess sources and have UKIDSS near-IR public data. They are clearly separated into two parts on the Y - K/g - z color-color diagram, and 59 of them meet or lie close to a newly proposed Y - K/g - z selection criterion for z < 4 quasars. Of these 59 sources, 44 were previously identified as quasars in SDSS DR7, and 35 of them are quasars at 2.2 < z < 3. We present spectroscopic observations of 14 of 15 remaining quasar candidates using the Bok 2.3 m telescope and the MMT 6.5 m telescope, and successfully identify all of them as new quasars at z = 2.36-2.88. We also apply this method to a sample of 643 variable quasar candidates with SDSS-UKIDSS nine-band photometric data selected from 1875 new quasar candidates in SDSS Stripe 82 given by Butler and Bloom based on the time-series selections, and find that 188 of them are probably new quasars with photometric redshifts at 2.2 < z < 3. Our results indicate that the combination of optical variability and optical/near-IR colors is probably the most efficient way to find 2.2 < z < 3 quasars and is very helpful for constructing a complete quasar sample. We discuss its implications for ongoing and upcoming large optical and near-IR sky surveys.

  14. Optical Spectroscopy of the Classical Novae V339 Del (2013) and V5668 Sgr (2015 No. 2)

    NASA Astrophysics Data System (ADS)

    Wagner, R. Mark; Woodward, Charles E.; Starrfield, Sumner; Ilyin, Ilya; Strassmeier, Klaus G.; Page, Kim; Osborne, Julian P.; Beardmore, Andrew P.

    2016-01-01

    We report the results of optical spectroscopy of the gamma-ray classical novae V339 Del (2013) and V5668 Sgr (PNV J18365700-2855420/Nova Sgr 2015 No. 2) supplemented by UV and X-ray observations obtained with Swift. Our spectra were obtained with the Steward Observatory Bok 2.3 m telescope (+B&C), the MDM 2.4 m Hiltner telescope (+OSMOS), the 6.5 m MMT (+BlueChannel), and the 2 x 8.4 m Large Binocular Telescope (+MODS1 and PEPSI) between 2013 August and 2015 September. The PEPSI spectra cover all or part of the 384-907 nm spectral region at a resolution of up to 270,000 (1 km/s). This is the highest resolution available on any 8-10 m class telescope. V339 Del was discovered on 2015 August 14.58 by Itagaki at V about 6.8. This nova reached a peak magnitude of about 4.3 making it one of the brightest novae of this century. Because of its exceptional brightness it has been observed at a variety of wavelengths and by a host of observatories both on the ground and in space. V5668 Sgr was discovered on 2015 March 15.634 by Seach at a magnitude of 6.0. It subsequently reached a maximum brightness of about 4.0 in late March. High resolution PEPSI spectra obtained in early April show dramatic variations in the multi-component P Cygni-type line profiles. V5668 Sgr was observed to form dust in June thereafter fading to about 13th magnitude. Our recent observations show that it has now evolved into the nebular phase. SS acknowledges partial support from NSF and NASA grants to ASU. CEW acknowledges support from NASA.

  15. Suppressed Expression of T-Box Transcription Factors is Involved in Senescence in Chronic Obstructive Pulmonary Disease

    SciTech Connect

    Acquaah-Mensah, George; Malhotra, Deepti; Vulimiri, Madhulika; McDermott, Jason E.; Biswal, Shyam

    2012-06-19

    Chronic obstructive pulmonary disease (COPD) is a major global health problem. The etiology of COPD has been associated with apoptosis, oxidative stress, and inflammation. However, understanding of the molecular interactions that modulate COPD pathogenesis remains only partly resolved. We conducted an exploratory study on COPD etiology to identify the key molecular participants. We used information-theoretic algorithms including Context Likelihood of Relatedness (CLR), Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNE), and Inferelator. We captured direct functional associations among genes, given a compendium of gene expression profiles of human lung epithelial cells. A set of genes differentially expressed in COPD, as reported in a previous study were superposed with the resulting transcriptional regulatory networks. After factoring in the properties of the networks, an established COPD susceptibility locus and domain-domain interactions involving protein products of genes in the generated networks, several molecular candidates were predicted to be involved in the etiology of COPD. These include COL4A3, CFLAR, GULP1, PDCD1, CASP10, PAX3, BOK, HSPD1, PITX2, and PML. Furthermore, T-box (TBX) genes and cyclin-dependent kinase inhibitor 2A (CDKN2A), which are in a direct transcriptional regulatory relationship, emerged as preeminent participants in the etiology of COPD by means of senescence. Contrary to observations in neoplasms, our study reveals that the expression of genes and proteins in the lung samples from patients with COPD indicate an increased tendency towards cellular senescence. The expression of the anti-senescence mediators TBX transcription factors, chromatin modifiers histone deacetylases, and sirtuins was suppressed; while the expression of TBX-regulated cellular senescence markers such as CDKN2A, CDKN1A, and CAV1 was elevated in the peripheral lung tissue samples from patients with COPD. The critical balance between senescence

  16. A coumarin derivative (RKS262) inhibits cell-cycle progression, causes pro-apoptotic signaling and cytotoxicity in ovarian cancer cells

    PubMed Central

    Singh, Rakesh K.; Lange, Thilo S.; Kim, Kyu Kwang

    2011-01-01

    Summary Coumarin derivative RKS262 belongs to a new class of potential anti-tumor agents. RKS262 was identified by structural optimization of Nifurtimox which is currently undergoing phase II clinical trials to treat high-risk neuroblastoma. In a NCI60 cell-line assay RKS262 exhibited significant cytotoxicity in ovarian cancer cells and a variety of other cell lines exceeding effects of commercial drugs such as cisplatin, 5-FU, cyclophosphamide or sapacitabine. Various leukemia cell-lines were most sensitive (GI50:~10 nM) while several non-small cell lung cancer cell lines and few cell lines from other tissues were relatively resistant (GI50> *1µM) to RKS262 treatment. The mechanism of cytotoxicity was examined using ovarian cancer cell-line OVCAR-3 as a model. RKS262 treatment resulted in a reduced mitochondria-transmembrane-depolarization potential. RKS262 effects included up-regulation of apoptotic markers and were not correlated with activation of proapoptotic MAP-Kinases (p38, SAP/JNK). RKS262 exerted strong inhibitory effects on oncogene ras, down-regulated DNA-pk KU-80 subunit expression and caused activation of Akt. A signature effect of RKS262 is the regulation of the mitochondrial Bcl2-family pathway. Pro-apoptotic factors Bid, Bad and Bok were up-regulated while expression of pro-survival factors Bcl-xl and Mcl-1 was inhibited. Moreover, at sub-cytotoxic doses RKS262 delayed OVCAR-3 cell-cycle progression through G2 phase and up-regulated p27 while cyclin-D1 and Cdk-6 were down-regulated, indicating that RKS262 is a specific cyclin/CDK inhibitor. In summary, RKS262 has been identified as a molecule belonging to a new class of potential chemotherapeutic agents affecting the viability of multiple cancer cell-lines and causing selective adverse effects on the viability of ovarian cancer cells. PMID:19865799

  17. Plant growth inhibition by cis-cinnamoyl glucosides and cis-cinnamic acid.

    PubMed

    Hiradate, Syuntaro; Morita, Sayaka; Furubayashi, Akihiro; Fujii, Yoshiharu; Harada, Jiro

    2005-03-01

    Spiraea thunbergii Sieb. contains 1-O-cis-cinnamoyl-beta-D-glucopyranose (CG) and 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose (BCG) as major plant growth inhibiting constituents. In the present study, we determined the inhibitory activity of CG and BCG on root elongation of germinated seedlings of lettuce (Lactuca sativa), pigweed (Amaranthus retroflexus), red clover (Trifolium pratense), timothy (Phleum pratense), and bok choy (Brassica rapa var chinensis) in comparison with that of two well-known growth inhibitors, 2,4-dichlorophenoxyacetic acid (2,4-D) and (+)-2-cis-4-trans-abscisic acid (cis-ABA), as well as two related chemicals of CG and BCG, cis-cinnamic acid (cis-CA) and trans-cinnamic acid (trans-CA). The EC50 values for CG and BCG on lettuce were roughly one-half to one-quarter of the value for cis-ABA. cis-Cinnamic acid, which is a component of CG and BCG, possessed almost the same inhibitory activity of CG and BCG, suggesting that the essential chemical structure responsible for the inhibitory activity of CG and BCG is cis-CA. The cis-stereochemistry of the methylene moiety is apparently needed for high inhibitory activity, as trans-CA had an EC50 value roughly 100 times that of CG, BCG, and cis-CA. Growth inhibition by CG, BCG, and cis-CA was influenced by the nature of the soil in the growing medium: alluvial soil preserved the bioactivity, whereas volcanic ash and calcareous soils inhibited bioactivity. These findings indicate a potential role of cis-CA and its glucosides as allelochemicals for use as plant growth regulators in agricultural fields. PMID:15898503

  18. Urinary isothiocyanate excretion, brassica consumption, and gene polymorphisms among women living in Shanghai, China.

    PubMed

    Fowke, Jay H; Shu, Xiao-Ou; Dai, Qi; Shintani, Ayumi; Conaway, C Clifford; Chung, Fung-Lung; Cai, Qiuyin; Gao, Yu-Tang; Zheng, Wei

    2003-12-01

    Alternative measures of Brassica vegetable consumption (e.g., cabbage) may clarify the association between Brassica and cancer risk. Brassica isothiocyanates (ITCs) are excreted in urine and may provide a sensitive and food-specific dietary biomarker. However, the persistence of ITCs in the body may be brief and dependent on the activity of several Phase II enzymes, raising questions about the relationship between a single ITC measure and habitual dietary patterns. This study investigates the association between urinary ITC excretion and habitual Brassica consumption, estimated by a food frequency questionnaire, among healthy Chinese women enrolled in the Shanghai Breast Cancer Study. Participants (n = 347) completed a validated food frequency questionnaire querying habitual dietary intake during the prior 5 years and provided a fasting first-morning urine specimen. Genetic deletion of glutathione S-transferases (GSTM1/GSTT1), and single nucleotide substitutions in GSTP1 (A313G) and NAD(P)H:quinone oxidoreductase 1 (NQO1: C609T), were identified from blood DNA. Urinary ITC excretion levels were marginally higher with the GSTT1-null or GSTP1-G/G genotypes (P = 0.07, P = 0.05, respectively). Mean habitual Brassica intake was 98.3 g/day, primarily as bok choy, and Brassica intake significantly increased across quartile categories of ITC levels. The association between habitual Brassica intake and urinary ITC levels was stronger among women with GSTT1-null or GSTP1-A/A genotypes, or NQO1 T-allele, and the interaction was statistically significant across GSTP1 genotype. In conclusion, a single urinary ITC measure, in conjunction with markers of Phase II enzyme activity, provides a complementary measure of habitual Brassica intake among Shanghai women. PMID:14693750

  19. [Effects of aging time on the form transformation and eco-toxicity threshold (ECx) of added Zn in typical China soils].

    PubMed

    Lin, Lei; Chen, Shi-Bao; Liu, Ji-Fang; Ma, Yi-Bing

    2013-07-01

    Six typical China soils with different properties were selected and added with seven concentrations of ZnCl2 to study the effects of different aging time (14, 90, 180, 360, and 540 days) on the form transformation and eco-toxicity threshold (ECx) of added Zn in the soils, with the main affecting factors analyzed. The results indicated that with the increase of aging time, the fraction of 0.01 mol x L(-1) CaCl2-extracted Zn in the soils decreased sharply initially, then slowed down, and reached the dynamic balance after 540 d incubation. The eco-toxicity thresholds (ECx, x = 10, 50) of Zn to bok choy increased significantly with aging time (P < 0.05), which implied the marked decrease of the phyto-toxicity of Zn. The measured aging factors AF10 and AF50 of Zn ranged from 1.077-1.743 and 1.174-1.441, respectively, and increased with aging time. The balanced concentration of Zn in the soils was significantly negatively correlated with soil pH, CEC, and organic carbon (Org-C) content, and soil pH was the most important controlling factor, followed by CEC and Org-C. It took shorter time to reach Zn balance in the soils with higher pH. The prediction model of the ECx of Zn was developed based on the aging factors and the main soil properties, and could be well validated by the measured ECx under field condition. This study would provide theoretical basis for the normalization of the eco-toxicity thresholds of added Zn in different soils and the formulation of the environmental criterion of Zn in China soils. PMID:24175536

  20. Perspectives on the Happiness of Community-Dwelling Elderly in Korea

    PubMed Central

    Jeon, Sang Won; Lee, Jongha; Lim, JaeHyoung; Jeong, Hyun-Ghang; Park, Moon Ho; Ko, Young-Hoon; Pae, Chi-Un; Kim, Seung Hyun; Joe, Sook-Haeng; Steffens, David C.

    2016-01-01

    Objective A community survey was performed to investigate the factors and perspectives associated with happiness among the elderly in Korea (≥60 years). Methods Eight hundred volunteers selected from participants in the Ansan Geriatric study (AGE study) were enrolled, and 706 completed the survey. The Happiness Questionnaire (HQ), which asks four questions about happiness, was administered. To explore the relationship between happiness and depression, the Geriatric Depression Scale (GDS) and the Beck Depression Inventory (BDI) also were administered. Results The participants' average level of happiness, determined using a 100-mm visual analogue scale (VAS) of the HQ, was 64.7±26.0. The happiest situations for most people were "getting together with family" (23.8%) and "living in peace with family members (well-being)" (13.2%). Frequent reasons for not being happy were "worsened health condition" (28.7% of the not-happy group), "economic problems of their own" (16.5%), and "economic problems of their children" (14.8%). The participants' choices regarding the essential conditions for happiness were "good health" (65.3%) and "being with family" (20.5%). The BDI and GDS scores were negatively related to the happiness score. A preliminary scale [Happy (Haeng-Bok, 幸福) aging scale] based on the HQ for measuring the happiness level of the Korean elderly was suggested for follow-up studies. Conclusion The most important factors determining the happiness of the community-dwelling elderly in Korea were good family relationships, economic stability, and good health. A higher depression score negatively impacted happiness among Korean elders. Further studies on the factors in their happiness are required. PMID:26766946

  1. Near-IR Spectral Variability of Young Stars

    NASA Astrophysics Data System (ADS)

    Zajac, Stephanie; Eisner, J. A.; Rudolph, A.

    2011-01-01

    Young stars (such as T Tauri and Herbig Ae/Be sources) exhibit photometric variability across the electromagnetic spectrum, including in the visible and infrared regions. Time-variable mass accretion rates may cause some of the observed variability, although other mechanisms such as starspots or structural changes in the circumstellar disks, provide alternative explanations. Spectroscopic observations provide a means to probe accretion via diagnostic emission lines, and to probe the ratio of stellar-to-circumstellar flux via veiling of stellar absorption lines. While spectroscopic variability in the optical range has been previously investigated, variability in the near-IR has not been explored as thoroughly. We have undertaken a project to track the spectral variability of young stars in the near-IR. Using the 90-inch Bok telescope on Kitt Peak, we observed about 40 young stars with FSPEC during two five-night runs separated by one month. As this project continues, in order to extend the timescales covered by our data, we will survey the same targets under similar circumstances in the summer of 2011. Ultimately, we hope to follow a sample of about 100 young stars with five-night observing runs every month of the year. Here we present initial results showing Brackett gamma Hydrogen line emission for several sources. We show that the emission line luminosity varies, and we use this variability to constrain the mass accretion rate with time for the observed objects. We acknowledge the NSF for funding under Award No. AST-0847170, a PAARE Grant for the Calfornia-Arizona Minority Partnership for Astronomy Research and Education (CAMPARE).

  2. VizieR Online Data Catalog: SDSS-RM project: technical overview (Shen+, 2015)

    NASA Astrophysics Data System (ADS)

    Shen, Y.; Brandt, W. N.; Dawson, K. S.; Hall, P. B.; McGreer, I. D.; Anderson, S. F.; Chen, Y.; Denney, K. D.; Eftekharzadeh, S.; Fan, X.; Gao, Y.; Green, P. J.; Greene, J. E.; Ho, L. C.; Horne, K.; Jiang, L.; Kelly, B. C.; Kinemuchi, K.; Kochanek, C. S.; Paris, I.; Peters, C. M.; Peterson, B. M.; Petitjean, P.; Ponder, K.; Richards, G. T.; Schneider, D. P.; Seth, A.; Smith, R. N.; Strauss, M. A.; Tao, C.; Trump, J. R.; Wood-Vasey, W. M.; Zu, Y.; Eisenstein, D. J.; Pan, K.; Bizyaev, D.; Malanushenko, V.; Malanushenko, E.; Oravetz, D.

    2015-02-01

    Our reverberation mapping (RM) field is the Pan-STARRS 1 (PS1) Medium Deep Field (MDF) MD07 (RAJ2000=213.704, DEJ2000=+53.083), which is a 7deg2 field within the CFHT-LS W3 field. This field is fully covered in the SDSS-I/II and SDSS-III BOSS footprints. The final RM sample contains 849 quasars, each of which was assigned a fiber on the RM plates. The remaining fibers were allocated to calibration sources, including 70 spectrophotometric standard stars, 80 sky fibers, and 1 LRG target (enforced by the BOSS tiling algorithm, but actually not tiled on any existing object in SDSS imaging). The BOSS spectroscopic observations were acquired during 7 dark/gray runs from 2014 January 1 to 2014 July 3. The separation between epochs in a given run is roughly 3-4 days, but varies from run to run under different weather conditions. Typically five epochs were taken for each run when weather permitted, totaling 32 epochs. The main portion of the RM imaging of our program is obtained with the CFHT/MegaCam and the Steward Observatory Bok 2.3m/90Prime. Given that our RM sample covers a wide redshift range, the photometric monitoring is performed in the SDSS g band and i band to sample the quasar continuum at low and high redshifts, respectively. We also had six nights of KPNO-4m (Mayall)/MOSAIC-1.1 observation to perform multi-band (Ugriz) imaging of the RM field. (4 data files).

  3. Political Activity at Harvard College Observatory in the Shapley ERA (1921-1952): Controversy and Consequences.

    NASA Astrophysics Data System (ADS)

    Welther, Barbara L.

    1993-12-01

    Soon after Harlow Shapley became director of HCO in 1921, he established himself as a scientist who would speak out and take action on national and international issues. Recognizing the importance of international cooperation in astronomy, he frequently traveled abroad and in turn invited foreign scientists to visit and work at HCO. By the mid-1930s, Shapley was actively rescuing refugee scientists in war-torn Europe and placing them in American universities. Both Harvard and the FBI took note of his activities. Shapley feared intervention of any kind from either academia or the government. Desperate for funding, however, he finally went to Washington and lobbied Congress to set up the NSF. Through 1945, when Truman succeeded Roosevelt, Shapley pursued his political activities freely. That year he travelled to Moscow to represent Harvard at the 220th anniversary celebration of the Academy of Sciences. In Moscow he advocated international cooperation between Soviet and American scientists. Consequently, Shapley was subpoenaed for interrogation in 1946 by John Rankin, who served during the Truman administration as a one-man committee to investigate un-American activities. The ordeal infuriated Shapley. Headlines about it infuriated some Harvard alumni who urged the university to fire him. Although Shapley was nearing retirement, President Conant stood by his right to keep his job. By 1950, when Senator Joseph McCarthy was compiling a list of Communist sympathizers in the State Department, the FBI had a dossier on Shapley. McCarthy subpoenaed Shapley, but could not intimidate him. The Senator continued the witch hunt with Shapley's associates. First he harassed Martha Betz Shapley, then Donald Menzel. Both cleared themselves. Other associates, such as Bart Bok, were spared. Ultimately, the interrogation worked in Menzel's favor. It disassociated him from Shapley's ideology and political activities. When the Harvard Corporation sought the next director of HCO, Menzel

  4. Models and observations of the millimeter and submillimeter molecular line emission of bright-rimmed clouds

    NASA Astrophysics Data System (ADS)

    de Vries, Christopher Hugh

    2003-07-01

    We present the results of a comparison of new millimeter and submillimeter molecular line survey of bright-rimmed clouds, observed at FCRAO in the CO (J = 1 → 0), C18O (J = 1 → 0), HCO+ (J = 1 → 0), H 13CO+ (J = 1 → 0), and N 2H+ (J = 1 → 0) transitions, at the HHT in the CO (J = 2 → 1), HCO+ ( J = 3 → 2), HCO+ (J = 4 → 3), H13CO+ (J = 3 → 2), and H13CO+ (J = 4 → 3), and at the CSO in the HCO+ (J = 4 → 3) and H13CO+ (J = 4 → 3) molecular line transitions with synthetic observations of a hydrodynamic shock driven triggered star formation model. We also present observations of three Bok globules done for comparison with the bright- rimmed clouds. We find that the appearance of the millimeter CO and HCO+ emission is dominated by the morphology of the shock front in the bright-rimmed clouds. The HCO + (J = 1 → 0) emission tends to trace the swept up gas ridge and overdense regions which may be triggered to collapse as a result of sequential star formation. The morphologies of the observed bright-rimmed cloud are in good agreement with the our modeled emission. Five of the seven bright-rimmed clouds we observe seem to have an outflow, however only one shows the spectral line blue-asymmetric signature that is indicative of infall, in the optically thick HCO+ emission. We also present evidence that in bright-rimmed clouds the nearby shock front may heat the core from outside-in thereby washing out the normally observed line infall signatures seen in isolated star forming regions. We find that the derived core masses of these bright-rimmed clouds are similar to other low and intermediate mass star forming regions.

  5. Coagulation of grains in static and collapsing protostellar clouds

    NASA Technical Reports Server (NTRS)

    Weidenschilling, S. J.; Ruzmaikina, T. V.

    1994-01-01

    We simulate collisional evolution of grains in dense turbulent molecular cloud cores (or Bok globules) in static equilibrium and free-fall collapse, assuming spherical symmetry. Relative velocities are due to thermal motions, differential settling, and turbulence, with the latter dominant for sonic turbulence with an assumed Kolmogorov spectrum. Realistic criteria are used to determine outcomes of collisions (coagulation vs. destruction) as functions of particle size and velocity. Results are presented for a variety of cloud parameters (radial density profile, turbulent velocity) and particle properties (density, impact strength). Results are sensitive to the assumed mechanical properties (density and impact strength) of grain aggregates. Particle growth is enhanced if aggregates have low density or fractal structures. On a timescale of a few Myr, an initial population of 0.1 micrometers grains may produce dense compact particles approximately 1 micrometer in size, or fluffy aggregates approximately 100 micrometers. For impact strengths less than or equal to 10(exp 6) ergs/g, a steady state is reached between coagulation of small grains and collisional disruption of larger aggregates. Formation of macroscopic aggregates requires high mechanical strengths and low aggregate densities. We assume sonic turbulence during collapse, with varied eddy size scales determining the dissipation rate or turbulence strength. The degree of collisional evolution during collapse is sensitive to the assumed small-scale structure (inner sc ale) of the turbulence. Weak turbulence results in few collisions and preserves the precollapse particle size distribution with little change. Strong turbulence tends to produce net destruction, rather than particle growth, during infall, unless inpact strengths are greater than 10(exp 6)ergs/g.

  6. Reverberation Mapping with Intermediate-band Photometry: Detection of Broad-line Hα Time Lags for Quasars at 0.2 < z < 0.4

    NASA Astrophysics Data System (ADS)

    Jiang, Linhua; Shen, Yue; McGreer, Ian D.; Fan, Xiaohui; Morganson, Eric; Windhorst, Rogier A.

    2016-02-01

    We present a reverberation mapping (RM) experiment that combines broad- and intermediate-band photometry; it is the first such attempt targeting 13 quasars at 0.2 < z < 0.9. The quasars were selected to have strong Hα or Hβ emission lines that are located in one of three intermediate bands (with FWHM around 200 Å) centered at 8045, 8505, and 9171 Å. The imaging observations were carried out in the intermediate bands and the broad i and z bands using the prime-focus imager 90Prime on the 2.3 m Bok telescope. Because of the large (˜1 deg2) field of view (FOV) of 90Prime, we included the 13 quasars within only five telescope pointings or fields. The five fields were repeatedly observed over 20-30 epochs that were unevenly distributed over a duration of 5-6 months. The combination of the broad- and intermediate-band photometry allows us to derive accurate light curves for both optical continuum emission (from the accretion disk) and line emission (from the broad-line region, or BLR). We detect Hα time lags between the continuum and line emission in six quasars. These quasars are at relatively low redshifts 0.2 < z < 0.4. The measured lags are consistent with the current BLR size-luminosity relation for Hβ at z < 0.3. While this experiment appears successful in detecting lags of the bright Hα line, further investigation is required to see if it can also be applied to the fainter Hβ line for quasars at higher redshifts. Finally we demonstrate that, by using a small telescope with a large FOV, intermediate-band photometric RM can be efficiently executed for a large sample of quasars at z > 0.2.

  7. The Colors of Hilda Group Asteroids: Complications For Use in Testing Dynamical Models

    NASA Astrophysics Data System (ADS)

    Ryan, Erin L.; Noll, Keith; Woodward, Charles E.

    2014-11-01

    Hilda group asteroids are in a stable 3:2 resonance with Jupiter which may have been reshaped by giant planet migration in the early epochs of solar system formation. Although the population is currently dynamically stable, the dynamics of this population suggest at minimum an inward migration of Jupiter by ~0.4 AU (Franklin et al. 2004, AJ, 128, 1391). As this population of objects is relatively isolated, compositional types can be used to test dynamical models such as the Grand Tack and Nice Model which suggest that objects of outer solar system (beyond Saturn) origin would be found in the Hilda population. We have undertaken a multi-year observational program at the 2.3-m Bok Telescope to obtain compositional types for a large sample of Hilda group asteroids. With a preliminary sample of ~400 objects from our observations and the literature, we find complications for direct compositional tests of the giant planet migration models. Specifically, we find that the two dynamical families within the Hilda group, Schubart and Hilda, have disparate dynamical ages ( 1.7 +/- 0.7 Gyr vs > 4 Gyr ; Broz & Vokrouhlicky 2008, MNRAS, 390, 715) but similar colors not seen elsewhere in the Hilda group population. This suggests dynamical family members should be removed from samples when using Hilda group asteroid compositions as a test of giant planet migration models. This research was supported by an appointment to the NASA Postdoctoral Program at Goddard Space Flight Center, administered by Oak Ridge Associated Universities through a contract with NASA. This work also funded by NASA Planetary Astronomy Grant NNX13AJ11G.

  8. Formation of CO in turbulent PDR`s

    NASA Astrophysics Data System (ADS)

    Röllig, M.; Hegmann, M.; Hengel, C.; Kegel, W. H.

    Based on an approach by G. Traving and collaborators (cf. Gail et al. 1974), we developed a comprehensive numerical code to deal with density and velocity fluctuations in radiative transfer problems (Albrecht & Kegel 1987, Kegel et al. 1993, Piehler & Kegel 1995, Hegmann 1999). In the last two years we have performed observations at the HHT and collected data of several Bok globules in the CO(2-1), CO(3-2), 13CO(2-1) and C18O(2-1)lines. For an analysis of the data we use the model of Kegel et al. which describes an isothermal spherical cloud being stabelized by turbulent and thermal pressure, considering the turbulent velocity field to be stochastic. In order to fit the observations to this model it turned out to be neccessary to implement an cut off radius for the CO density distribution. We hereby first relied on calculations of van Dishoeck & Black (1988) who accounted for the complicated CO photodissociation process dominated by line rather than continuous absorption using a simplified radiative transfer model. To model the radiation transfer more realistically we calculate the CO density distribution self consistently with the radiation field in a turbulent molecular cloud with regard to a chemical network incorporating 26 different molecules and over 200 chemical reactions. Since the photodissociation of CO is dominated by line absorption turbulence has a substantial influence an the CO density distribution in the outher region of molecular clouds which is an important factor in every model that tries to explain observations of molecular clouds.

  9. Life Cycle of Stars

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In this stunning picture of the giant galactic nebula NGC 3603, the crisp resolution of NASA's Hubble Space Telescope captures various stages of the life cycle of stars in one single view. To the upper left of center is the evolved blue supergiant called Sher 25. The star has a unique circumstellar ring of glowing gas that is a galactic twin to the famous ring around the supernova 1987A. The grayish-bluish color of the ring and the bipolar outflows (blobs to the upper right and lower left of the star) indicates the presence of processed (chemically enriched) material. Near the center of the view is a so-called starburst cluster dominated by young, hot Wolf-Rayet stars and early O-type stars. A torrent of ionizing radiation and fast stellar winds from these massive stars has blown a large cavity around the cluster. The most spectacular evidence for the interaction of ionizing radiation with cold molecular-hydrogen cloud material are the giant gaseous pillars to the right of the cluster. These pillars are sculptured by the same physical processes as the famous pillars Hubble photographed in the M16 Eagle Nebula. Dark clouds at the upper right are so-called Bok globules, which are probably in an earlier stage of star formation. To the lower left of the cluster are two compact, tadpole-shaped emission nebulae. Similar structures were found by Hubble in Orion, and have been interpreted as gas and dust evaporation from possibly protoplanetary disks (proplyds). This true-color picture was taken on March 5, 1999 with the Wide Field Planetary Camera 2.

  10. Spectral analysis and abundances of the post-HB star HD 76431

    NASA Astrophysics Data System (ADS)

    Khalack, V.; Yameogo, B.; LeBlanc, F.; Fontaine, G.; Green, E.; Van Grootel, V.; Petit, P.

    2014-12-01

    HD 76431 is a slow rotating post-HB star that shows an underabundance of helium by 0.5 dex relative to the solar value. These observational facts suggest that atomic diffusion could be active in its atmosphere. We have used the MMT and Bok spectra to estimate the atmospheric parameters of the target star using the model atmospheres and synthetic spectra calculated with TLUSTY and SYNSPEC. The derived values of the effective temperature, surface gravity, and helium abundance are consistent with those obtained by Ramspeck et al. It appears that non-local thermodynamic equilibrium (NLTE) effects are not important for HD 76431. We have used Stokes I spectra from ESPaDOnS at CFHT to perform an abundance analysis and a search for observational evidence of vertical stratification of the abundance of certain elements. The results of our abundance analysis are in good agreement with previously published data with respect to average abundances. Our numerical simulations show that carbon and nitrogen reveal signatures of vertical abundance stratification in the atmosphere of HD 76431. It appears that the carbon abundance increases towards the deeper atmospheric layers. Nitrogen also shows a similar behaviour, but in deeper atmospheric layers we obtain a significant dispersion for the estimates of its abundance. To our knowledge, this is the first demonstration of vertical abundance stratification of metals in a post-HB star and up to now it is the hottest star to show such stratification features. We also report the detection of two Si III and one Ti III emission lines in the spectra of HD 76431 that were not detected in previous studies.

  11. Extended Lyα Nebulae at z ≃ 2.3: An Extremely Rare and Strongly Clustered Population?

    NASA Astrophysics Data System (ADS)

    Yang, Yujin; Zabludoff, Ann; Tremonti, Christy; Eisenstein, Daniel; Davé, Romeel

    2009-03-01

    To obtain an unbiased sample of bright Lyα blobs (L_{Lyα} ≳ 10^{43} erg s-1), we have undertaken a blind, wide-field, narrowband imaging survey in the National Optical Astronomy Observatory Deep Wide Field Survey Boötes field with the Steward Bok 2.3 m telescope. After searching over 4.82 deg2 at z = 2.3, we discover four Lyα blobs with L_{Lyα} = 1.6-5.3 × 1043 erg s-1, isophotal areas of 28-57 ⊓⊔, and broad Lyα line profiles (Δv = 900-1250 km s-1). In contrast with the extended Lyα halos associated with high-z radio galaxies, none of our four blobs are radio-loud. The X-ray luminosities and optical spectra of these blobs are diverse. Two blobs (3 and 4) are X-ray detected with LX (2-7 keV) = 2-4 × 1044 erg s-1 and have broad optical emission lines (C IV) characteristic of active galactic nucleus (AGN), implying that 50% of our sample blobs are associated with a strong AGN. The other 50% of the blobs (1 and 2) are not X-ray or optically detected as AGN down to similar limits. The number density of the four blobs is ~3 × 10-6 h 3 70 Mpc-3, comparable to that of galaxy clusters at similar redshifts and 3× lower than that found in the SSA22 proto-cluster at z = 3.1, even after accounting for the over-density of that region. The two X-ray undetected blobs are separated by only 70'' (550 kpc) and have almost identical redshifts (lsim360 kpc along the line of sight), suggesting that they are part of the same system. Given the rarity of the blobs and our discovery of a close pair, we speculate that blobs occupy the highest density regions and thus may be precursors of today's rich-cluster galaxies. Observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution.

  12. Rotating molecular outflows: the young T Tauri star in CB 26

    NASA Astrophysics Data System (ADS)

    Launhardt, R.; Pavlyuchenkov, Ya.; Gueth, F.; Chen, X.; Dutrey, A.; Guilloteau, S.; Henning, Th.; Piétu, V.; Schreyer, K.; Semenov, D.

    2009-01-01

    Context: The disk-outflow connection is thought to play a key role in extracting excess angular momentum from a forming proto-star. Although jet rotation has been observed in a few objects, no rotation of molecular outflows has been unambiguously reported so far. Aims: We report new millimeter-interferometric observations of the edge-on T Tauri star - disk system in the isolated Bok globule CB 26. The aim of these observations was to study the disk-outflow relation in this 1 Myr old low-mass young stellar object. Methods: The IRAM PdBI array was used to observe 12CO(2-1) at 1.3 mm in two configurations, resulting in spectral line maps with 1.5´´ resolution. We use an empirical parameterized steady-state outflow model combined with 2-D line radiative transfer calculations and χ^2-minimization in parameter space to derive a best-fit model and constrain parameters of the outflow. Results: The data reveal a previously undiscovered collimated bipolar molecular outflow of total length ≈2000 AU, escaping perpendicular to the plane of the disk. We find peculiar kinematic signatures that suggest that the outflow is rotating with the same orientation as the disk. However, we could not ultimately exclude jet precession or two misaligned flows as possible origins of the observed peculiar velocity field. There is indirect indication that the embedded driving source is a binary system, which, together with the youth of the source, could provide a clue to the observed kinematic features of the outflow. Conclusions: CB 26 is so far the most promising source in which to study the rotation of a molecular outflow. Assuming that the outflow is rotating, we compute and compare masses, mass flux, angular momenta, and angular momentum flux of the disk and outflow and derive disk dispersal timescales of 0.5 ldots 1 Myr, comparable to the age of the system. Based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG

  13. Biological activity of piceatannol: leaving the shadow of resveratrol.

    PubMed

    Piotrowska, Hanna; Kucinska, Malgorzata; Murias, Marek

    2012-01-01

    Resveratrol (3,4',5-trans-trihydroxystilbene), a naturally occurring stilbene, is considered to have a number of beneficial effects, including anticancer, anti-aethrogenic, anti-oxidative, anti-inflammatory, anti-microbial and estrogenic activity. Piceatannol (3, 3', 4, 5'-trans-trihydroxystilbene), a naturally occurring hydroxylated analogue of resveratrol, is less studied than resveratrol but displays a wide spectrum of biological activity. Piceatannol has been found in various plants, including grapes, passion fruit, white tea, and Japanese knotweed. Besides antioxidative effects, piceatannol exhibits potential anticancer properties as suggested by its ability to suppress proliferation of a wide variety of tumor cells, including leukemia, lymphoma; cancers of the breast, prostate, colon and melanoma. The growth-inhibitory and proapoptotic effects of piceatannol are mediated through cell-cycle arrest; upregulation of Bid, Bax. Bik, Bok, Fas: P21(WAF1) down-regulation of Bcl-xL; BCL-2, clAP, activation of caspases (-3, -7,- 8, -9), loss of mitochondrial potential, and release of cytochrome c. Piceatannol has been shown to suppress the activation of some transcription factors, including NF-kappaB, which plays a central role as a transcriptional regulator in response to cellular stress caused by free radicals, ultraviolet irradiation, cytokines, or microbial antigens. Piceatannol also inhibits JAK-1, which is a key member of the STAT pathway that is crucial in controlling cellular activities in response to extracellular cytokines and is a COX-2-inducible enzyme involved in inflammation and carcinogenesis. Although piceatannol has been shown to induce apoptosis in cancer cells, there are examples of its anti-apoptotic pro-proliferative activity. Piceatannol inhibits Syk kinase, which plays a crucial role in the coordination of immune recognition receptors and orchestrates multiple downstream signaling pathways in various hematopoietic cells. Piceatannol also binds

  14. Tabulation of comet observations.

    NASA Astrophysics Data System (ADS)

    1998-04-01

    Concerning comets: C/1940 R2 (Cunningham), C/1941 B2 (de Kock-Paraskevopoulos), C/1941 K1 (van Gent), C/1942 X1 (Whipple-Fedtke-Tevzadze), C/1946 C1 (Timmers), C/1946 K1 (Pajdušáková-Rotbart-Weber), C/1946 P1 (Jones), C/1946 U1 (Bester), C/1947 S1 (Bester), C/1947 X1 (Southern comet), C/1947 Y1 (Mrkos), C/1948 E1 (Pajdušáková-Mrkos), C/1948 L1 (Honda-Bernasconi), C/1948 V1 (Eclipse comet), C/1949 N1 (Bappu-Bok-Newkirk), C/1950 K1 (Minkowski), C/1951 C1 (Pajdušáková), C/1952 H1 (Mrkos), C/1952 M1 (Peltier), C/1952 Q1 (Harrington), C/1953 G1 (Mrkos-Honda), C/1953 T1 (Abell), C/1954 O1 (Vozárová), C/1955 L1 (Mrkos), C/1955 N1 (Bakharev-Macfarlane-Krienke), C/1955 O1 (Honda), C/1956 E1 (Mrkos), C/1956 R1 (Arend-Roland), C/1957 P1 (Mrkos), C/1957 U1 (Latyshev-Wild-Burnham), C/1959 Q1 (Alcock), C/1959 Q2 (Alcock), C/1959 Y1 (Burnham), C/1995 O1 (Hale-Bopp), C/1996 J1 (Evans-Drinkwater), C/1996 P2 (Russell-Watson), C/1997 BA6 (Spacewatch), C/1997 D1 (Mueller), C/1997 J1 (Mueller), C/1997 J2 (Meunier-Dupouy), C/1997 N1 (Tabur), C/1997 T1 (Utsunomiya), 10P/Tempel 2, 21P/Giacobini-Zinner, 29P/Schwassmann-Wachmann 1, 43P/Wolf-Harrington, 55P/Tempel-Tuttle, 62P/Tsuchinshan 1, 69P/Taylor, 78P/Gehrels 2, 81P/Wild 2, 88P/Howell, 95P/Chiron, 103P/Hartley 2, 104P/Kowal 2, 111P/Helin-Roman-Crockett, 118P/Shoemaker-Levy 4, 121P/Shoemaker-Holt 2, 129P/Shoemaker-Levy 3, 134P/Kowal-Vavrova, P/1997 C1 (Gehrels), P/1997 G1 (Montani).

  15. Molecular and Histopathological Changes in Mouse Intestinal Tissue after Proton Exposure

    NASA Astrophysics Data System (ADS)

    Purgason, Ashley; Zhang, Ye; Hamilton, Stanley; Wu, Honglu

    Radiation in space, especially energetic protons emitted from solar particle events (SPEs), poses serious health risks to astronauts and is especially dangerous for long duration missions. Protons are the most abundant particles in space and to date there is little known about the details of the negative consequences crew members will face upon exposure to them. To elucidate some of the possible health effects induced by protons, BALB/C mice were subjected to 250 MeV of proton radiation at doses of 0 Gy, 0.1 Gy, 1 Gy, and 2 Gy. Three specimens per dose were studied. The gastrointestinal tract of each animal was dissected four hours post-irradiation and the isolated small intestinal tissue was fixed in formalin for histopathological examination or snap-frozen in liquid nitrogen for RNA isolation. Histopathologic observation of the tissue using standard HE staining methods to screen for morphologic changes showed a marked increase in apoptotic lesions for even the lowest dose of 0.1 Gy, and the dose response showed possible hyper sensitivities at low dose. Tissue of the gastrointestinal tract was also homogenized and RNA was isolated for cDNA synthesis and real-time PCR analysis for genes involved in apoptosis. Results of gene expression changes revealed consistent up or down regulation of a number of genes for all of the exposure doses that may play a role in proton-induced apoptosis (e.g. Hsp90ab1). In addition, several genes were found to have significant changes in the RNA level after only the low dose (0.1 Gy), but not the high dose (1 and 2 Gy), proton exposures (e.g. Bok and Casp1), whereas some genes had expression changes only after high dose proton exposures (e.g. Tsc22d3). These findings demonstrated that apoptosis may occur in gastrointestinal tracts after even low dose proton exposures, and the different gene expression patterns between low and high dose proton irradiated mice may offer insight into the molecular mechanisms of the possible hyper

  16. Spacewatch Observations of Near-Earth Objects

    NASA Astrophysics Data System (ADS)

    McMillan, Robert S.; Bressi, T. H.; Scotti, J. V.; Larsen, J. A.; Perry, M. L.

    2012-10-01

    We have enhanced Spacewatch's (McMillan et al. 2007 IAU Symp. 236) astrometry and photometry of Near-Earth Objects (NEOs). We specialize in follow-up of the Congressionally-mandated "large" NEOs (absolute mag H≤22) as they recede from Earth after discovery and become fainter, as well as NEOs on impact risk pages, Potentially Hazardous Asteroids, and NEOs observed by WISE (Mainzer et al. 2012 ApJ 752, id 110). Spacewatch was the pre-eminent follower-up of NEOs discovered by WISE within 2 weeks of their discovery. We have observed at elongations as small as 46°. Follow-up on longer orbital arcs improves understanding of the statistics of the orbits and absolute magnitudes of the population as well as the recoverability of individual objects. The new CCD which we began operating on our 1.8-m telescope on 2011 Oct 16 makes 23rd mag asteroids more frequently accessible. Faster readout and smaller pixels yield 67% more observations of NEOs per year and astrometric residuals of ±0.3 arcsec, vs. ±0.6 arcsec on NEOs with the old CCD. To reach more distant objects with H≤22, we now also use the Bok 2.3-meter telescope of Steward Observatory and the Kitt Peak National Observatory (KPNO) 4-m Mayall telescope. About 2800 tracklets of NEOs were accepted by the MPC from Spacewatch in the interval 2011 Jul 1 - 2012 Jun 30. The archive of images collected with our mosaic of CCDs on the 0.9-m telescope of Steward Observatory now approaches 15 TB in size and spans almost 10 years of uniformly conducted surveying. It contributes incidental followup astrometry and precoveries of NEOs. This work is funded by NASA/NEOO grants NNX11AB52G and NNX12AG11G, the Brinson Foundation of Chicago, IL, the estates of R. S. Vail and R. L. Waland, and other private donors. Spacewatch uses facilities of KPNO and services of the IAU’s Minor Planet Center.

  17. Planetary Doppler Imaging

    NASA Astrophysics Data System (ADS)

    Murphy, N.; Jefferies, S.; Hart, M.; Hubbard, W. B.; Showman, A. P.; Hernandez, G.; Rudd, L.

    2014-12-01

    from space, however, much can be learned about Jupiter and Saturn using ground-based measurements. We will present the first results from a ground-based observing campaign of Jupiter and Saturn, made from the Bok 90" telescope on Kitt Peak, intended to validate the work of Gaulme et al, and extend such observations to Saturn.

  18. Spectropolarimetry of B-type and C-type asteroids: Phase Curves and Wavelength Dependence

    NASA Astrophysics Data System (ADS)

    Maleszewski, C.; McMillan, R. S.; Smith, P. S.

    2014-12-01

    We present recent spectropolarimetric observations of eleven B- and C-type asteroids using SPOL (http://james.as.arizona.edu/~psmith/SPOL/) at the 2.3-m Bok and 1.6-m Kuiper telescopes. Our primary goal is to further constrain our understanding of the wavelength dependence of linear polarization. For each object, we produced polarimetric phase curves (linear polarization vs. phase angle) and measure the wavelength dependence in each observation by calculating the slope of each polarization spectrum. Previous analysis by Belskaya et al. (2009) shows that the slope of the polarization spectrum increases as the wavelength increases. No analysis of the wavelength dependence in B-types has occurred previously to our knowledge. For the five C-type (3 Ch- and 2 C-) objects observed, those of the Ch-type have larger minimum polarizations than of the C- subtype. This is consistent with polarimetric phase curves of similar asteroids by Gil-Hutton and Cañada-Assandri (2012). With respect to the wavelength dependence, our observed targets show an increase in polarization slope with wavelength, confirming the Belskaya (2009) result. After dividing the data by group, C- subtype objects have relatively flat polarization spectra, as opposed to the Ch- subtypes that have more rapidly changing slopes as phase angle increases. A mineralogical basis for the variety of wavelength dependences observed is most likely. Additional observations of the other C- subtypes will aid to distinguish how mineralogical variation affects polarization. It may also explain the wide range of polarization slopes measured near a phase angle of ten degrees in the Belskaya (2009) analysis. Six B-type asteroids were observed in a similar manner. As with the C-types, the polarimetric phase curves vary in shape, suggesting differences in albedo. Also, the wavelength dependence increases with wavelength, as shown for the C-types. On the other hand, all of the B-type objects have a similar wavelength dependence

  19. THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: TECHNICAL OVERVIEW

    SciTech Connect

    Shen, Yue; Brandt, W. N.; Dawson, Kyle S.; Hall, Patrick B.; McGreer, Ian D.; Fan, Xiaohui; Anderson, Scott F.; Chen, Yuguang; Denney, Kelly D.; Eftekharzadeh, Sarah; Gao, Yang; Green, Paul J.; Greene, Jenny E.; Ho, Luis C.; Horne, Keith; Kelly, Brandon C.; and others

    2015-01-01

    The Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project is a dedicated multi-object RM experiment that has spectroscopically monitored a sample of 849 broad-line quasars in a single 7 deg{sup 2} field with the SDSS-III Baryon Oscillation Spectroscopic Survey spectrograph. The RM quasar sample is flux-limited to i {sub psf} = 21.7 mag, and covers a redshift range of 0.1 < z < 4.5 without any other cuts on quasar properties. Optical spectroscopy was performed during 2014 January-July dark/gray time, with an average cadence of ∼4 days, totaling more than 30 epochs. Supporting photometric monitoring in the g and i bands was conducted at multiple facilities including the Canada-France-Hawaii Telescope (CFHT) and the Steward Observatory Bok telescope in 2014, with a cadence of ∼2 days and covering all lunar phases. The RM field (R.A., decl. = 14:14:49.00, +53:05:00.0) lies within the CFHT-LS W3 field, and coincides with the Pan-STARRS 1 (PS1) Medium Deep Field MD07, with three prior years of multi-band PS1 light curves. The SDSS-RM six month baseline program aims to detect time lags between the quasar continuum and broad line region (BLR) variability on timescales of up to several months (in the observed frame) for ∼10% of the sample, and to anchor the time baseline for continued monitoring in the future to detect lags on longer timescales and at higher redshift. SDSS-RM is the first major program to systematically explore the potential of RM for broad-line quasars at z > 0.3, and will investigate the prospects of RM with all major broad lines covered in optical spectroscopy. SDSS-RM will provide guidance on future multi-object RM campaigns on larger scales, and is aiming to deliver more than tens of BLR lag detections for a homogeneous sample of quasars. We describe the motivation, design, and implementation of this program, and outline the science impact expected from the resulting data for RM and general quasar science.

  20. The Flagstaff Meeting in June 1964

    NASA Astrophysics Data System (ADS)

    Baars, J. W. M.

    1999-05-01

    My most memorable AAS meeting is the first one, the 116th meeting in Flagstaff , AZ, June 1964. I had been at the NRAO in Green Bank for less than a year and this was going to be my first presentation at a scientific conference. I traveled with my Director, Dave Heeschen, from the newly opened Dulles Airport near Washington non stop to Tucson (try that these days of hub-hopping!). In Tucson, I was met by a friend who exposed me to a phenomenon, unknown in West Virginia: the drive-in liquor store. In those days, the AAS could comfortably meet in a small city like Flagstaff. Today this would be impossible; Flagstaff has grown slower than the AAS. I was fascinated to see and hear many astronomers, but I don't remember how my own presentation went. The most memorable event was the talk presented hors concours by Bart Bok, who had just returned from Australia to become Director of Steward Observatory. He would give an unscheduled ten minute talk on the new Anglo-Australian Telescope, but instead treated us to a most exciting story of the beauty of the Southern Sky and its astronomical wonders. He went on for 25 minutes without the Chairman daring to stop him! All following speakers were curtailed by a minute and the session finished on time. Flagstaff was, as it is now, a quiet town. There was a bar next to my motel, where I drank two Heineken every day. On the last day, there was no more Heineken. As the bar man said: `I had a six pack and you drank me out of it'. Such was the business acumen in Flagstaff in the mid sixties. Impressive was the trip to Oak Creek Canyon and Sedona, where we visited the Chapel, beautifully placed in the hills nearby. I felt the harmony between nature and building was perfect. Encroaching development, right up to the church, have taken away much of the serenity of the place. The evening flight out of Flagstaff was delayed by a summer storm. At the airport, Martin Schwarzschild chatted with me for half an hour and I was barely aware how

  1. X-ray fluorescence (XRF) scanning of discrete samples: Examples from the loess-paleosol sequence on the Island of Susak, Croatia

    NASA Astrophysics Data System (ADS)

    Profe, Jörn; Wacha, Lara; Frechen, Manfred; Rolf, Christian; Brlek, Mihovil; Ohlendorf, Christian; Zolitschka, Bernd

    2016-04-01

    Loess-paleosol sequences (LPS) are recognized as valuable terrestrial environmental archives. Although LPS provide discontinuous archives, high-resolution sampling and analyzing strategies are required for a sound reconstruction of past environmental conditions. Up to now, proxies such as grain size, rock magnetic properties and calcium-carbonate content are commonly investigated at the centimeter scale, whereas the elemental as well as the mineralogical compositions are analyzed at a much coarser resolution, e.g. with 10 cm intervals or once for every lithological unit. X-ray fluorescence (XRF) scanning of discrete powdered and homogenized samples is a new application of the XRF core-scanner technology providing a tool for fast and non-destructive qualitative measurement of the elemental composition along LPS. Tracking relative changes of the elemental distribution at the centimeter scale is considered as an important supplement to existing methods applied to LPS in order to gain a more detailed knowledge about weathering, dust provenance and sedimentation dynamics. The island of Susak, situated in the north-eastern Adriatic Sea, represents an exceptional site with Pleistocene aeolian sediments of up to 90 m thickness covering at least the last glacial-interglacial cycle. The studied sub-profiles are part of loess cliffs located directly on the coast of Susak (Bok-Bay). Therefore, this record qualifies as a test candidate for benchmarking XRF scanning of discrete samples against magnetic susceptibility, organic carbon and lithological data. The following elements are studied as proxies for weathering (K, Ca, Sr, Rb), for dust provenance (Al, Si, Ti, Zr) and for organic matter (S, Br). In addition, Fe is directly linked to magnetic susceptibility. First results indicate a general agreement between lithologically identified paleosols and element weathering indices. Fe is predominantly positively correlated with magnetic susceptibility. The Ti/Zr-ratio points to a

  2. Physical characterization of fast rotator NEOs

    NASA Astrophysics Data System (ADS)

    Kikwaya Eluo, Jean-Baptiste; Hergenrother, Carl W.

    2015-08-01

    Understanding the physical characteristics of fast rotator NEOs (sub-km sizes with H > 22) is important for two reasons: to establish properties that can constraint models of their potential hazard, and to learn about the origin and the evolution of the solar system. Technically it is difficult to cover different ranges of wavelengths using one telescope with one instrument. Setting up a network of telescopes with different instruments observing simultaneously the same object will efficiently contribute to the characterization of NEOs.ART (Arizona Robotic Telescope) is a University of Arizona initiative whose goal is to use local 2-m size telescopes to provide near real-time observations of Target of Opportunity objects covering the visible and the near- infrared wavelengths. We plan to use three telescopes of the ART project to observe fast rotator NEOs: 1) VATT (Vatican Advanced Technology Telescope) at Mount Graham (longitude: -109.8719, latitude: 32.7016, elevation: 10469 feet) with VATT-4K optical imager for photometry to estimate colors, lightcurves to get the rotation rate, and estimate the phase angle function of NEOs, 2) Bok 2.3 m at Kitt Peak (longitude: -111.6004, latitude: 31.9629, elevation: 6795 feet) with BCSpec (Boller & Chivens Spectrograph) for visible spectroscopy, and 3) Kuiper 1.5-m at Mount Bigelow (longitude: -110.7345, latitude: 32.4165, elevation: 8235 feet) with a near-infrared instrument.We report here the preliminary results of several NEOs whose rotation rate, color, and type have been estimated using photometry with images recorded with VATT-4K. 2009 SQ104 has a rotation rate of 6.85+/- 0.03 h, 2014 AY28 has a rotation rate of 0.91 +/- 0.02 h, 2014 EC of 0.54 +/-0.04 h, 2014 FA44 of 3.45 +/- 0.05 h, 2014 KS40 of 1.11 +/- 0.06 h, 2011 PT of 0.17 +/- 0.05 h, 2014 SC324 of 0.36 +/- 0.43 h, 2014 WF201 of 1.00 +/- 0.03 h. Of these objects, 2014 HM2, 2014 FA, 2014 SB145, 2011 PT fall among X-type asteroids; 2014 KS, 2014 WF are likely to be

  3. Tentative critical levels of tropospheric ozone for agricultural crops in Japan

    NASA Astrophysics Data System (ADS)

    Yonekura, T.

    2010-12-01

    Ground level ozone concentrations have increased year by year in Japan. High ozone concentrations have been known to affect growth and yield of agricultural crops. In the US and Europe, much effort has been directed to establish regulatory policies such as secondary air quality standard and critical levels to protect vegetation against ozone. On the contrary, in Japan, there is a few data of agricultural crops sensitivity to ozone. Furthermore, there is no information about the ozone risk of agricultural crop loss by based on ozone index (e.g. AOT40, SUM06, W126)-crop response relationship, yet. The objects of our research are: (1) to screen sensitivity of ozone on 10 crops cultivated in urban area in Japan. (2) to establish critical levels of ozone for protecting agricultural crops based on ozone index-crop response relationship. The 10 Japanese agricultural crops such as Japanese rice, Hanegi (Welsh onion), Shungiku (Crown daisy), Saradana (Lettus), Hatsukadaikon (Radish), Kokabu (Small Turnip), Santosai (Chinese cabbage), Tasai (Spinach mustard), Komatsuna (Japanese mustard spinach) and Chingensai (Bok Choy), were fumigated to three levels of ozone (clean air (< 5 ppbv), ambient level of ozone, 1.5 times ambient ozone) in open-top chambers during 30 to 120 days. Those experiments were repeated five times during two growing season. Throughout the experimental period, the growth or yield were measured, and the relationship between growth (or yield) and ozone index was examined. As a result, the influences of ozone on growth or yield were different among 10 crops. Relatively good correlations of coefficients of determination (r2) for linear regressions to growth or yield were obtained with “8h means” and “AOT40” rather than “SUM00”, “SUM06” and “W126”. Critical level for 10 crops in terms of an AOT40 were 1.1 to 2.1 ppm h per month. The ozone sensitive crop in our study was sound to be 1.0 ppm h per month in AOT40.

  4. The incidence of rugby-related catastrophic injuries (including cardiac events) in South Africa from 2008 to 2011: a cohort study

    PubMed Central

    Brown, James Craig; Lambert, Mike I; Verhagen, Evert; Readhead, Clint; van Mechelen, Willem; Viljoen, Wayne

    2013-01-01

    Objectives To establish an accurate and comprehensive injury incidence registry of all rugby union-related catastrophic events in South Africa between 2008 and 2011. An additional aim was to investigate correlates associated with these injuries. Design Prospective. Setting The South African amateur and professional rugby-playing population. Participants An estimated 529 483 Junior and 121 663 Senior rugby union (‘rugby’) players (population at risk). Outcome measures Annual average incidences of rugby-related catastrophic injuries by type (cardiac events, traumatic brain and acute spinal cord injuries (ASCIs)) and outcome (full recoveries—fatalities). Playing level (junior and senior levels), position and event (phase of play) were also assessed. Results The average annual incidence of ASCIs and Traumatic Brain Injuries combined was 2.00 per 100 000 players (95% CI 0.91 to 3.08) from 2008 to 2011. The incidence of ASCIs with permanent outcomes was significantly higher at the Senior level (4.52 per 100 000 players, 95% CI 0.74 to 8.30) than the Junior level (0.24 per 100 000 players, 95% CI 0 to 0.65) during this period. The hooker position was associated with 46% (n=12 of 26) of all permanent ASCI outcomes, the majority of which (83%) occurred during the scrum phase of play. Conclusions The incidence of rugby-related catastrophic injuries in South Africa between 2008 and 2011 is comparable to that of other countries and to most other collision sports. The higher incidence rate of permanent ASCIs at the Senior level could be related to the different law variations or characteristics (eg, less regular training) compared with the Junior level. The hooker and scrum were associated with high proportions of permanent ASCIs. The BokSmart injury prevention programme should focus efforts on these areas (Senior level, hooker and scrum) and use this study as a reference point for the evaluation of the effectiveness of the programme. PMID:23447464

  5. A Systems Engineering Approach to Quality Assurance for Aerospace Testing

    NASA Technical Reports Server (NTRS)

    Shepherd, Christena C.

    2014-01-01

    On the surface, it appears that AS9100 has little to say about how to apply a Quality Management System (QMS) to major aerospace test programs (or even smaller ones). It also appears that there is little in the quality engineering Body of Knowledge (BOK) that applies to testing, unless it is nondestructive examination (NDE), or some type of lab or bench testing associated with the manufacturing process. However, if one examines: a) how the systems engineering (SE) processes are implemented throughout a test program; and b) how these SE processes can be mapped to the requirements of AS9100, a number of areas for involvement of the quality professional are revealed. What often happens is that quality assurance during a test program is limited to inspections of the test article; what could be considered a manufacturing al fresco approach. This limits the quality professional and is a disservice to the programs and projects, since there are a number of ways that quality can enhance critical processes, and support efforts to improve risk reduction, efficiency and effectiveness. The Systems Engineering (SE) discipline is widely used in aerospace to ensure the progress from Stakeholder Expectations (the President, Congress, the taxpayers) to a successful, delivered product or service. Although this is well known, what is not well known is that these same SE processes are implemented in varying complexity, to prepare for and implement test projects that support research, development, verification and validation, qualification, and acceptance test projects. Although the test organization's terminology may vary from the SE terminology, and from one test service provider to another, the basic process is followed by successful, reliable testing organizations. For this analysis, NASA Procedural Requirements (NPR) 7123.1, NASA Systems Engineering Processes and Requirements is used to illustrate the SE processes that are used for major aerospace testing. Many of these processes

  6. The Sloan Digital Sky Survey Reverberation Mapping Project: Technical Overview

    NASA Astrophysics Data System (ADS)

    Shen, Yue; Brandt, W. N.; Dawson, Kyle S.; Hall, Patrick B.; McGreer, Ian D.; Anderson, Scott F.; Chen, Yuguang; Denney, Kelly D.; Eftekharzadeh, Sarah; Fan, Xiaohui; Gao, Yang; Green, Paul J.; Greene, Jenny E.; Ho, Luis C.; Horne, Keith; Jiang, Linhua; Kelly, Brandon C.; Kinemuchi, Karen; Kochanek, Christopher S.; Pâris, Isabelle; Peters, Christina M.; Peterson, Bradley M.; Petitjean, Patrick; Ponder, Kara; Richards, Gordon T.; Schneider, Donald P.; Seth, Anil; Smith, Robyn N.; Strauss, Michael A.; Tao, Charling; Trump, Jonathan R.; Wood-Vasey, W. M.; Zu, Ying; Eisenstein, Daniel J.; Pan, Kaike; Bizyaev, Dmitry; Malanushenko, Viktor; Malanushenko, Elena; Oravetz, Daniel

    2015-01-01

    The Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project is a dedicated multi-object RM experiment that has spectroscopically monitored a sample of 849 broad-line quasars in a single 7 deg2 field with the SDSS-III Baryon Oscillation Spectroscopic Survey spectrograph. The RM quasar sample is flux-limited to i psf = 21.7 mag, and covers a redshift range of 0.1 < z < 4.5 without any other cuts on quasar properties. Optical spectroscopy was performed during 2014 January-July dark/gray time, with an average cadence of ~4 days, totaling more than 30 epochs. Supporting photometric monitoring in the g and i bands was conducted at multiple facilities including the Canada-France-Hawaii Telescope (CFHT) and the Steward Observatory Bok telescope in 2014, with a cadence of ~2 days and covering all lunar phases. The RM field (R.A., decl. = 14:14:49.00, +53:05:00.0) lies within the CFHT-LS W3 field, and coincides with the Pan-STARRS 1 (PS1) Medium Deep Field MD07, with three prior years of multi-band PS1 light curves. The SDSS-RM six month baseline program aims to detect time lags between the quasar continuum and broad line region (BLR) variability on timescales of up to several months (in the observed frame) for ~10% of the sample, and to anchor the time baseline for continued monitoring in the future to detect lags on longer timescales and at higher redshift. SDSS-RM is the first major program to systematically explore the potential of RM for broad-line quasars at z > 0.3, and will investigate the prospects of RM with all major broad lines covered in optical spectroscopy. SDSS-RM will provide guidance on future multi-object RM campaigns on larger scales, and is aiming to deliver more than tens of BLR lag detections for a homogeneous sample of quasars. We describe the motivation, design, and implementation of this program, and outline the science impact expected from the resulting data for RM and general quasar science.

  7. Variability of ionospheric scintillation near the equatorial anomaly crest of the Indian zone

    NASA Astrophysics Data System (ADS)

    Chatterjee, S.; Chakraborty, S. K.

    2013-04-01

    Multistation observations of ionosphere scintillation at VHF (250 MHz) and GNSS L1 frequency from three locations - (i) Bokkhali (BOK) (geographic 21.6° N, 88.2° E, dip 31.48°, (ii) Raja Peary Mohan College Centre (RPMC) (geographic 22.66° N, 88.4° E, dip 33.5°) and (iii) Krishnath College Centre (KNC), Berhampore (geographic 24.1° N, 88.3° E, dip 35.9°) - at ~ 1° latitudinal separations near the northern crest of the equatorial ionization anomaly (EIA) of the Indian longitude sector are investigated in conjunction with total electron content (TEC) data and available ionosonde data near the magnetic equator to study fine structure in spatial and temporal variability patterns of scintillation occurrences. The observations are carried out in the autumnal equinoctial months of a high solar activity year (2011). In spite of smaller latitudinal/spatial separation among the observing stations, conspicuous differences are reflected in the onset time, duration, fade rate and fade depth of VHF scintillations as well as in spectral features. Scintillations are mostly associated with depletion in TEC around the anomaly crest and occurrence of ESF near the magnetic equator at an earlier time. Not only the strength of EIA, but also the locations of observing stations with respect to the post-sunset resurgence peak of EIA seem to play dominant role in dictating the severity of scintillation activity. A secondary enhancement in diurnal TEC in the post-sunset period seems to accentuate the irregularity activities near the anomaly crest, and a threshold value of the same may fruitfully be utilized for the prediction of scintillation around the locations. An idea regarding latitudinal extent of scintillation is developed by considering observations at L1 frequency from the GPS and GLONASS constellation of satellites. A critical value of h'F near the magnetic equator for the occurrence of simultaneous scintillation at the three centres is suggested. The observations are

  8. Obituary: Frank K. Edmondson (1912-2008)

    NASA Astrophysics Data System (ADS)

    Pilachowski, Catherine A.; Olson, Margaret K. Edmondson; Edmondson, Frank K., Jr.

    2009-12-01

    Pluto's status to a dwarf planet. While in Flagstaff, Frank met Margaret Russell, the youngest daughter of famed American astronomer Henry Norris Russell of Princeton University. The young couple instantly bonded and became engaged after only two weeks. He and Margaret were married on November 24, 1934. Frank and Margaret remained inseparable until her death in 1999, always together at meetings of the American Astronomical Society, the International Astronomical Union, and elsewhere. Studying under astronomer Bart Bok, Frank received his Ph.D. in astronomy in 1937 from Harvard University, where he completed his dissertation on "The Absorption of Light in the Galaxy," and joined the faculty as an Instructor in Astronomy at Indiana University. Frank became the second member of the Astronomy Department, with Professor W. A. Cogshall, housed in Kirkwood Observatory. Frank served as chair of the department from 1944 until 1978. Under his leadership, the University acquired the Goethe Link Observatory in Brooklyn, IN, (a gift from Dr. Goethe Link, a noted Indianapolis physician and avid amateur astronomer), established a graduate program in astronomy, and enlarged the Department of Astronomy from two faculty members to eight. In one of his favorite stories, Edmondson bet Professor Cogshall a chocolate ice cream cone that President Herman B Wells would fund a new position for the Department, knowing full well that Wells had already agreed. Frank retired from IU in 1983. Studying under astronomer Bart Bok, Frank received his Ph.D. in astronomy in 1937 from Harvard University, where he completed his dissertation on "The Absorption of Light in the Galaxy," and joined the faculty as an Instructor in Astronomy at Indiana University. Frank became the second member of the Astronomy Department, with Professor W. A. Cogshall, housed in Kirkwood Observatory. Frank served as chair of the department from 1944 until 1978. Under his leadership, the University acquired the Goethe Link

  9. VISTA Stares Deeply into the Blue Lagoon

    NASA Astrophysics Data System (ADS)

    2011-01-01

    This new infrared image of the Lagoon Nebula was captured as part of a five-year study of the Milky Way using ESO's VISTA telescope at the Paranal Observatory in Chile. This is a small piece of a much larger image of the region surrounding the nebula, which is, in turn, only one part of a huge survey. Astronomers are currently using ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA) to scour the Milky Way's central regions for variable objects and map its structure in greater detail than ever before. This huge survey is called VISTA Variables in the Via Lactea (VVV) [1]. The new infrared image presented here was taken as part of this survey. It shows the stellar nursery called the Lagoon Nebula (also known as Messier 8, see eso0936), which lies about 4000-5000 light-years away in the constellation of Sagittarius (the Archer). Infrared observations allow astronomers to peer behind the veil of dust that prevents them from seeing celestial objects in visible light. This is because visible light, which has a wavelength that is about the same size as the dust particles, is strongly scattered, but the longer wavelength infrared light can pass through the dust largely unscathed. VISTA, with its 4.1-metre diameter mirror - the largest survey telescope in the world - is dedicated to surveying large areas of the sky at near-infrared wavelengths deeply and quickly. It is therefore ideally suited to studying star birth. Stars typically form in large molecular clouds of gas and dust, which collapse under their own weight. The Lagoon Nebula, however, is also home to a number of much more compact regions of collapsing gas and dust, called Bok globules [2]. These dark clouds are so dense that, even in the infrared, they can block the starlight from background stars. But the most famous dark feature in the nebula, for which it is named, is the lagoon-shaped dust lane that winds its way through the glowing cloud of gas. Hot, young stars, which give off intense

  10. Obituary: Allan R. Sandage (1926-2010)

    NASA Astrophysics Data System (ADS)

    Devorkin, David

    2011-12-01

    Weart on 22 May 1978, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD, USA, www.aip.org/history/ohilist/ and http://www.aip.org/history/ohilist/4380_1.html] Allan enrolled in Miami University in 1943 because his father was on the faculty there at the time. He majored in physics until he entered the Navy for 18 months to train as an electronics technician's mate. His training began in Chicago, where he became acquainted with others interested in astronomy, like Arthur Code and Albert Wilson, and then his tour took him to Gulfport, Mississippi, and finally to Treasure Island in the San Francisco Bay. When Sandage was discharged from the Navy his father was moving to the University of Illinois, so Allan transferred there, entering a much larger and more competitive physics department. He majored in physics and mathematics but he also minored in philosophy, and took a celestial mechanics course from Robert H. Baker. He volunteered to work at the observatory, learning the art and craft of calibrating photographic plates so that magnitudes could be transferred and intercompared from plate to plate, an experience that he later realized prepared him well for his life career and also introduced him into Bart Bok's "star counting" circuit based at Harvard. In consequence, when Bok visited Illinois sometime in 1947, he invited Sandage to work at Harvard in their summer school at the Agassiz Station mapping Milky Way fields. Sandage applied both to Harvard and Caltech for graduate school. Harvard was very well established in its graduate program whereas Caltech was just beginning to offer the Ph.D. in astronomy. He chose Caltech because that was where the big telescopes were. His family had visited Mount Wilson in 1941 during a summer when his father was teaching at Berkeley, and since that time Sandage had dreamed of observing with those giant telescopes. Thus in September 1948, Sandage joined the first class of students to engage in formal graduate

  11. VISTA Stares Deeply into the Blue Lagoon

    NASA Astrophysics Data System (ADS)

    2011-01-01

    This new infrared image of the Lagoon Nebula was captured as part of a five-year study of the Milky Way using ESO's VISTA telescope at the Paranal Observatory in Chile. This is a small piece of a much larger image of the region surrounding the nebula, which is, in turn, only one part of a huge survey. Astronomers are currently using ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA) to scour the Milky Way's central regions for variable objects and map its structure in greater detail than ever before. This huge survey is called VISTA Variables in the Via Lactea (VVV) [1]. The new infrared image presented here was taken as part of this survey. It shows the stellar nursery called the Lagoon Nebula (also known as Messier 8, see eso0936), which lies about 4000-5000 light-years away in the constellation of Sagittarius (the Archer). Infrared observations allow astronomers to peer behind the veil of dust that prevents them from seeing celestial objects in visible light. This is because visible light, which has a wavelength that is about the same size as the dust particles, is strongly scattered, but the longer wavelength infrared light can pass through the dust largely unscathed. VISTA, with its 4.1-metre diameter mirror - the largest survey telescope in the world - is dedicated to surveying large areas of the sky at near-infrared wavelengths deeply and quickly. It is therefore ideally suited to studying star birth. Stars typically form in large molecular clouds of gas and dust, which collapse under their own weight. The Lagoon Nebula, however, is also home to a number of much more compact regions of collapsing gas and dust, called Bok globules [2]. These dark clouds are so dense that, even in the infrared, they can block the starlight from background stars. But the most famous dark feature in the nebula, for which it is named, is the lagoon-shaped dust lane that winds its way through the glowing cloud of gas. Hot, young stars, which give off intense

  12. The low-mass YSO CB230-A: investigating the protostar and its jet with NIR spectroscopy and Spitzer observations

    NASA Astrophysics Data System (ADS)

    Massi, F.; Codella, C.; Brand, J.; di Fabrizio, L.; Wouterloot, J. G. A.

    2008-11-01

    Context: To investigate the earliest phases of star formation and study how newly-born stars interact with the surrounding medium, we performed a line and continuum survey at NIR and mm-wavelengths of a sample of relatively isolated Bok globules. Aims: We present a follow-up observational program of a star-forming site in the globule CB230. From narrow-band continuum observations of this site, we had discovered a bright [FeII] jet, which originates in the low-mass YSO CB230-A. We aim to investigate the physical properties of the region from where the jet is launched. Methods: Our analysis was carried out using low-resolution NIR spectra acquired with the camera NICS at the TNG telescope, with JH and HK grisms and a 1 arcsec-wide slit. These observational data were complemented with infrared photometric data from the Spitzer space telescope archive. Results: The relevant physical properties of CB230-A were constrained by SED fitting of fluxes from the NIR to the mm. The YSO spectrum exhibits a significant number of atomic and molecular emission lines and absorption features. The characteristics of this spectrum suggest that we are observing a region in the close vicinity of CB230-A, i.e. its photosphere and/or an active accretion disk. The spectra of the knots in the jet contain a large number of emission lines, including a rich set of [FeII] lines. Emission due to H2 and [FeII] are not spatially correlated, confirming that [FeII] and H2 are excited by different mechanisms, in agreement with the models where [FeII] traces dissociative J-shocks and molecular hydrogen traces slower C-shocks. By using intensity ratios involving density-sensitive [FeII] lines, we estimated the electron densities along the jet to be 6 × 10^3-1 × 104 cm-3. This indicates either high density post-shock regions of ionised gas or regions with a high degree of ionisation. Conclusions: By combining the present data with previously obtained maps at NIR- and mm-wavelengths, the emerging

  13. Leslie Peltier, Amateur Astronomer and Observer Extraordinaire

    NASA Astrophysics Data System (ADS)

    Corbin, B. G.

    2003-12-01

    surroundings. Peltier was a shy person who rarely left Delphos, and worked as a designer of children's furniture and toys until his death. However, he was widely recognized during his lifetime with articles about him appearing in popular magazines such as Reader's Digest and Newsweek. Many famous astronomers visited him at Delphos including W.W. Morgan, W.A. Hiltner, Donald Menzel, the Boks, and others. He received many honors including an honorary Doctor of Science degree from Bowling Green State University (Ohio) and the AAVSO's first Merit Award in 1934. Starlight Nights returned to print in 1999 with a foreword by David Levy, and is now introducing a new generation to the beauty and thrill of observing.

  14. Spectrum from Embedded Star in Herbig-Haro 46/47

    NASA Technical Reports Server (NTRS)

    2003-01-01

    NASA's Spitzer Space Telescope has lifted the cosmic veil to see an otherwise hidden newborn star, while detecting the presence of water and carbon dioxide ices, as well as organic molecules. Using near-infrared light, Spitzer pierces through an optically dark cloud to detect the embedded outflow in an object called HH 46/47. Herbig-Haro (HH) objects are bright, nebulous regions of gas and dust that are usually buried within dark dust clouds. They are formed when supersonic gas ejected from a forming protostar, or embryonic star, interacts with the surrounding interstellar medium. These young stars are often detected only in the infrared.

    HH 46/47 is a striking example of a low mass protostar ejecting a jet and creating a bipolar, or two-sided, outflow. The central protostar lies inside a dark cloud (known as a 'Bok globule') which is illuminated by the nearby Gum Nebula. Located at a distance of 1140 light-years and found in the constellation Vela, the protostar is hidden from view in the visible-light image (inset). With Spitzer, the star and its dazzling jets of molecular gas appear with clarity.

    The Spitzer image (inset) was obtained with the infrared array camera and is a three-color mosaic. Emission at 3.6 microns is shown as blue, emission from 4.5 and 5.8 microns has been combined as green, and 8.0 micron emission is depicted as red. The 8-micron channel of the camera is sensitive to emission from polycyclic aromatic hydrocarbons. These organic molecules, comprised of carbon and hydrogen, are excited by the surrounding radiation field and become luminescent, accounting for the reddish cloud. Note that the boundary layer of the 8-micron mission corresponds to the lower right edge of the dark cloud in the visible-light picture.

    The primary image shows a spectrum obtained with Spitzer's infrared spectrograph instrument, stretching from wavelengths of 5.5 microns (left) to 20 microns (right). Spectra are graphical representations of a celestial

  15. Obituary: Frank K. Edmondson (1912-2008)

    NASA Astrophysics Data System (ADS)

    Pilachowski, Catherine A.; Olson, Margaret K. Edmondson; Edmondson, Frank K., Jr.

    2009-12-01

    Pluto's status to a dwarf planet. While in Flagstaff, Frank met Margaret Russell, the youngest daughter of famed American astronomer Henry Norris Russell of Princeton University. The young couple instantly bonded and became engaged after only two weeks. He and Margaret were married on November 24, 1934. Frank and Margaret remained inseparable until her death in 1999, always together at meetings of the American Astronomical Society, the International Astronomical Union, and elsewhere. Studying under astronomer Bart Bok, Frank received his Ph.D. in astronomy in 1937 from Harvard University, where he completed his dissertation on "The Absorption of Light in the Galaxy," and joined the faculty as an Instructor in Astronomy at Indiana University. Frank became the second member of the Astronomy Department, with Professor W. A. Cogshall, housed in Kirkwood Observatory. Frank served as chair of the department from 1944 until 1978. Under his leadership, the University acquired the Goethe Link Observatory in Brooklyn, IN, (a gift from Dr. Goethe Link, a noted Indianapolis physician and avid amateur astronomer), established a graduate program in astronomy, and enlarged the Department of Astronomy from two faculty members to eight. In one of his favorite stories, Edmondson bet Professor Cogshall a chocolate ice cream cone that President Herman B Wells would fund a new position for the Department, knowing full well that Wells had already agreed. Frank retired from IU in 1983. Studying under astronomer Bart Bok, Frank received his Ph.D. in astronomy in 1937 from Harvard University, where he completed his dissertation on "The Absorption of Light in the Galaxy," and joined the faculty as an Instructor in Astronomy at Indiana University. Frank became the second member of the Astronomy Department, with Professor W. A. Cogshall, housed in Kirkwood Observatory. Frank served as chair of the department from 1944 until 1978. Under his leadership, the University acquired the Goethe Link

  16. Obituary: E. Dorrit Hoffleit, 1907-2007

    NASA Astrophysics Data System (ADS)

    Trimble, Virginia

    2007-12-01

    next year as a research assistant (later research associate) at Harvard College Observatory, then directed by Harlow Shapley, about whom her opinion was much warmer than that expressed by Cecilia Payne Gaposchkin. Dorrit's immediate supervisor at Harvard was Henrietta Swope, daughter of the President of General Electric, and eventually best known for work at Mount Wilson Observatory with Walter Baade on variable stars in the Magellanic Clouds, published in papers that continued to appear long after Baade's death. Hoffleit's first ten papers were also on variable stars and appeared in Harvard Observatory publications. But the MA she completed in 1932 was on the light curves of meteors and was published in the Proceedings of the United States National Academy of Sciences. By this time, Dorrit had established a work pattern that was to persist right up to retirement - at least 40 hours per week on whatever the current boss thought she should be doing, and another 20 or so on other astronomical research that interested her. Hffleit had supposed that an MA would be her highest degree, but Shapley urged her to go on for a PhD, with, it would seem, a bit of urging on both sides from Bart Bok, who informed her that "if God recommends that you do something, it is your duty to do it." The thesis (PhD 1938) was on yet a third topic, spectroscopic parallaxes. This means determining the luminosities of stars, hence their distances, from line width and ratio diagnostics in their spectra. The pioneer was Antonia Maury, whose insights were not appreciated by Shapley's predecessor, E. C. Pickering. Another valuable Hoffleit mentor was Ernst Öpik, on a three-month visit to Harvard in 1934, from whom Dorrit learned stellar statistics and half a dozen other things. The thesis also provided her "break out" paper into the Astrophysical Journal (on CN as a giant/dwarf discriminator). Hoffleit began to branch out into astrometry, comets, and other parts of astronomy and, starting in 1941

  17. Obituary: Allan R. Sandage (1926-2010)

    NASA Astrophysics Data System (ADS)

    Devorkin, David

    2011-12-01

    Weart on 22 May 1978, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD, USA, www.aip.org/history/ohilist/ and http://www.aip.org/history/ohilist/4380_1.html] Allan enrolled in Miami University in 1943 because his father was on the faculty there at the time. He majored in physics until he entered the Navy for 18 months to train as an electronics technician's mate. His training began in Chicago, where he became acquainted with others interested in astronomy, like Arthur Code and Albert Wilson, and then his tour took him to Gulfport, Mississippi, and finally to Treasure Island in the San Francisco Bay. When Sandage was discharged from the Navy his father was moving to the University of Illinois, so Allan transferred there, entering a much larger and more competitive physics department. He majored in physics and mathematics but he also minored in philosophy, and took a celestial mechanics course from Robert H. Baker. He volunteered to work at the observatory, learning the art and craft of calibrating photographic plates so that magnitudes could be transferred and intercompared from plate to plate, an experience that he later realized prepared him well for his life career and also introduced him into Bart Bok's "star counting" circuit based at Harvard. In consequence, when Bok visited Illinois sometime in 1947, he invited Sandage to work at Harvard in their summer school at the Agassiz Station mapping Milky Way fields. Sandage applied both to Harvard and Caltech for graduate school. Harvard was very well established in its graduate program whereas Caltech was just beginning to offer the Ph.D. in astronomy. He chose Caltech because that was where the big telescopes were. His family had visited Mount Wilson in 1941 during a summer when his father was teaching at Berkeley, and since that time Sandage had dreamed of observing with those giant telescopes. Thus in September 1948, Sandage joined the first class of students to engage in formal graduate

  18. Obituary: Donald Alexander Macrae, 1916-2006

    NASA Astrophysics Data System (ADS)

    Seaquist, E. R.

    2007-12-01

    With the passing of Donald Alexander MacRae on 6 December 2006 at age 90, the astronomy community lost a visionary scientist and a great educator in the field. Don MacRae was born in Halifax, Nova Scotia, on 19 February 1916, to Donald Alexander and Laura Geddes (Barnstead) MacRae. His father was originally a classics scholar and preceptor of Greek and Latin at Princeton, but at the time of Don's birth in 1916 he was Dean of the Dalhousie Law School in Halifax. The family moved to Toronto, Ontario, in 1924 when his father joined the faculty of Osgoode Hall Law School in Toronto as a Professor of Law. After the family moved to Toronto, where he received most of his early education, he obtained his undergraduate degree in Mathematics and Physics in 1937 from the University of Toronto (U of T). He obtained the degree of A.M. in 1940 and of Ph.D. in 1943 from Harvard University under the mentorship of Bart Bok in the field of galactic structure. During his early career he worked briefly at the University of Pennsylvania, Cornell University, and Carbide and Chemical Corporation at Oak Ridge, Tennessee. For Don the latter work was a brief and somewhat uneasy association with the Manhattan Project. In 1946, he obtained a position at Case Institute of Technology (now Case Western Reserve University), where he worked until 1953. In 1953, he accepted a position at the U of T, replacing Ralph Williamson, who had earlier introduced Don to the emerging field of radio astronomy while they both were at Cornell. Don's primary research field was stellar spectroscopy, but his interests were much broader than this, and he possessed an abiding ability to interest students and faculty in new and emerging ideas. In the early 1960s he developed a strong interest in the nature and origin of the lunar surface, and discussed these extensively with colleagues. Many of his ideas on this subject were later confirmed by the lunar exploration program. Don's continuing interest in radio astronomy

  19. Obituary: Donald Alexander Macrae, 1916-2006

    NASA Astrophysics Data System (ADS)

    Seaquist, E. R.

    2007-12-01

    With the passing of Donald Alexander MacRae on 6 December 2006 at age 90, the astronomy community lost a visionary scientist and a great educator in the field. Don MacRae was born in Halifax, Nova Scotia, on 19 February 1916, to Donald Alexander and Laura Geddes (Barnstead) MacRae. His father was originally a classics scholar and preceptor of Greek and Latin at Princeton, but at the time of Don's birth in 1916 he was Dean of the Dalhousie Law School in Halifax. The family moved to Toronto, Ontario, in 1924 when his father joined the faculty of Osgoode Hall Law School in Toronto as a Professor of Law. After the family moved to Toronto, where he received most of his early education, he obtained his undergraduate degree in Mathematics and Physics in 1937 from the University of Toronto (U of T). He obtained the degree of A.M. in 1940 and of Ph.D. in 1943 from Harvard University under the mentorship of Bart Bok in the field of galactic structure. During his early career he worked briefly at the University of Pennsylvania, Cornell University, and Carbide and Chemical Corporation at Oak Ridge, Tennessee. For Don the latter work was a brief and somewhat uneasy association with the Manhattan Project. In 1946, he obtained a position at Case Institute of Technology (now Case Western Reserve University), where he worked until 1953. In 1953, he accepted a position at the U of T, replacing Ralph Williamson, who had earlier introduced Don to the emerging field of radio astronomy while they both were at Cornell. Don's primary research field was stellar spectroscopy, but his interests were much broader than this, and he possessed an abiding ability to interest students and faculty in new and emerging ideas. In the early 1960s he developed a strong interest in the nature and origin of the lunar surface, and discussed these extensively with colleagues. Many of his ideas on this subject were later confirmed by the lunar exploration program. Don's continuing interest in radio astronomy

  20. Obituary: E. Dorrit Hoffleit, 1907-2007

    NASA Astrophysics Data System (ADS)

    Trimble, Virginia

    2007-12-01

    next year as a research assistant (later research associate) at Harvard College Observatory, then directed by Harlow Shapley, about whom her opinion was much warmer than that expressed by Cecilia Payne Gaposchkin. Dorrit's immediate supervisor at Harvard was Henrietta Swope, daughter of the President of General Electric, and eventually best known for work at Mount Wilson Observatory with Walter Baade on variable stars in the Magellanic Clouds, published in papers that continued to appear long after Baade's death. Hoffleit's first ten papers were also on variable stars and appeared in Harvard Observatory publications. But the MA she completed in 1932 was on the light curves of meteors and was published in the Proceedings of the United States National Academy of Sciences. By this time, Dorrit had established a work pattern that was to persist right up to retirement - at least 40 hours per week on whatever the current boss thought she should be doing, and another 20 or so on other astronomical research that interested her. Hffleit had supposed that an MA would be her highest degree, but Shapley urged her to go on for a PhD, with, it would seem, a bit of urging on both sides from Bart Bok, who informed her that "if God recommends that you do something, it is your duty to do it." The thesis (PhD 1938) was on yet a third topic, spectroscopic parallaxes. This means determining the luminosities of stars, hence their distances, from line width and ratio diagnostics in their spectra. The pioneer was Antonia Maury, whose insights were not appreciated by Shapley's predecessor, E. C. Pickering. Another valuable Hoffleit mentor was Ernst Öpik, on a three-month visit to Harvard in 1934, from whom Dorrit learned stellar statistics and half a dozen other things. The thesis also provided her "break out" paper into the Astrophysical Journal (on CN as a giant/dwarf discriminator). Hoffleit began to branch out into astrometry, comets, and other parts of astronomy and, starting in 1941