5,258 research outputs found
Accretion-ejection connection in the young brown dwarf candidate ISO-Cha1 217
As the number of observed brown dwarf outflows is growing it is important to
investigate how these outflows compare to the well studied jets from young
stellar objects. A key point of comparison is the relationship between outflow
and accretion activity and in particular the ratio between the mass outflow and
accretion rates (/). The brown dwarf candidate
ISO-ChaI 217 was discovered by our group, as part of a spectro-astrometric
study of brown dwarfs, to be driving an asymmetric outflow with the
blue-shifted lobe having a position angle of 20. The aim here
is to further investigate the properties of ISO-ChaI 217, the morphology and
kinematics of its outflow, and to better constrain
(/). The outflow is spatially resolved in the
lines and is detected out to 1\farcs6
in the blue-shifted lobe and ~ 1" in the red-shifted lobe. The asymmetry
between the two lobes is confirmed although the velocity asymmetry is less
pronounced with respect to our previous study. Using thirteen different
accretion tracers we measure log() [M/yr]= -10.6
0.4. As it was not possible to measure the effect of extinction on the ISO-ChaI
217 outflow was derived for a range of values of A, up to
a value of A = 2.5 mag estimated for the source extinction. The logarithm
of the mass outflow () was estimated in the range -11.7 to -11.1
for both jets combined. Thus / [\Msun/yr] lies
below the maximum value predicted by magneto-centrifugal jet launching models.
Finally, both model fitting of the Balmer decrements and spectro-astrometric
analysis of the H line show that the bulk of the H I emission comes
from the accretion flow.Comment: accepted by Astronomy & Astrophysic
Effect of Photobiomodulation on Vinblastine-Poisoned Murine HERS Cells
Objective: The aim of this study was to investigate the effect of near-infrared (NIR) photobiomodulation on the proliferation and glutathione levels in murine Hertwig\u27s epithelial root sheath (HERS) cells after poisoning with vinblastine. Background: Photobiomodulation has been shown to improve wound healing in a number of animal models. There have been no studies on the effect of photobiomodulation on cancer-related chemotherapy injury to the cells that initiate tooth root growth. Materials and Methods: Control groups consisted of murine HERS cells without vinblastine (VB−) and cells with vinblastine at 10, 20, and 30 ng/mL (VB10, VB20, and VB30). Experimental groups consisted of these same groups with light therapy (VB-L, VB10L, VB20L, and VB30L). The cells were exposed to vinblastine for 1 h. Photobiomodulation consisted of a 75-cm2 gallium-aluminum-arsenide light-emitting diode (LED) array at an energy density of 12.8 J/cm2, delivered with 50 mW/cm2 power over 256 s. Results: Vinblastine alone significantly decreased HERS cell proliferation and glutathione levels at all concentrations (VB10 [−55%, p \u3c 1.0 × 10−8]; VB20 [−72%, p \u3c 1.0 × 10−9]; VB30 [−80%, p \u3c 1.0 × 10−10]; and VB10 [−36%, p \u3c 0.0001]; VB20 [−49%, p \u3c 1.0 × 10−6]; VB30 [−53%, p \u3c 1.0 × 10−7] respectively). Photobiomodulation significantly increased cell proliferation at all levels of vinblastine exposure (VB10L [+50%, p \u3c 0.0001]; VB20L [+45%, p \u3c 0.05]; VB30 [+39%, p \u3c 0.05]) but not of the control (+22%, p = 0.063). The photobiomodulation significantly increased glutathione production in all concentrations of vinblastine except 20 ng/mL (VB10L [+39%, p = 0.007]; VB20L [+19%, p = 0.087]; VB30 [+14%, p = 0.025]) and the control (+12%, p = 0.13). Conclusions: Photobiomodulation demonstrated an improvement in proliferation and glutathione levels in vinblastine-poisoned murine HERS cells
Knowledge Diffusion in R&D Groups: The Impact of Internet Technologies
Knowledge flows are the lifeblood of any R&D organisation. These firms are increasingly
discovering that the knowledge they require is often located beyond their boundaries. In this paper,
we investigate how R&D groups acquire and diffuse external knowledge and the role Internet
technologies play in this process. The focus of our study is on the technological gatekeeper. Previous
studies have found that gatekeepers are key nodes in the innovation process. These sporadic
individuals have the skills to identify useful knowledge outside the firm and disseminate this among
their local colleagues. However, much of the seminal gatekeeper research has been conducted over
two decades ago. In the time since, there have been huge advances in ICT and especially Internet
technologies. These technologies have dramatically altered how knowledge workers source and share
their information. Our objective is to advance the gatekeeper theory into an era where the knowledge
worker is saturated with information. Using case study methods, we examine knowledge flows in the
R&D group of an Irish medical devices firm. Our results indicate that due to advances in Internet
technology, the traditional gatekeeper no longer exists to any great extent. Instead, the modern R&D
lab acquires and diffuses external knowledge through a combination of a ‘web gatekeeper’ and a
‘knowledge transformer.
Stochastic Background Search Correlating ALLEGRO with LIGO Engineering Data
We describe the role of correlation measurements between the LIGO
interferometer in Livingston, LA, and the ALLEGRO resonant bar detector in
Baton Rouge, LA, in searches for a stochastic background of gravitational
waves. Such measurements provide a valuable complement to correlations between
interferometers at the two LIGO sites, since they are sensitive in a different,
higher, frequency band. Additionally, the variable orientation of the ALLEGRO
detector provides a means to distinguish gravitational wave correlations from
correlated environmental noise. We describe the analysis underway to set a
limit on the strength of a stochastic background at frequencies near 900 Hz
using ALLEGRO data and data from LIGO's E7 Engineering Run.Comment: 8 pages, 2 encapsulated PostScript figures, uses IOP class files,
submitted to the proceedings of the 7th Gravitational Wave Data Analysis
Workshop (which will be published in Classical and Quantum Gravity
PENGARUH KINERJA KEUANGAN DAN UKURAN PERUSAHAAN TERHADAP HARGA SAHAM (Studi pada Perusahaan Perbankan yang Terdaftar di Bursa Efek Indonesia Tahun 2012-2014)
Penelitian ini dilakukan untuk menguji pengaruh Kinerja Keuangan dan Ukuran Perusahaan terhadap Harga Saham pada Perusahaan Perbankan yang terdaftar di Bursa Efek Indonesia tahun 2012 sampai 2014. Variabel yang digunakan adalah Capital Adequacy Ratio (CAR), Non Performing Loan (NPL), Return On Asset (ROA), Loan to Deposit Ratio (LDR), Firm Size (Ukuran Perusahaan). Teknik sampling yang digunakan adalah purposive sampling selama kurun waktu penelitian tahun 2012 sampai 2014. Data diperoleh berdasarkan publikasi Indonesian Capital Market Directory (ICMD 2015). Dan diperoleh jumlah sampel sebanyak 18 perusahaan. Teknik analisis yang digunakan adalah regresi berganda dengan persamaan kuadrat terkecil dan uji hipotesis menggunakan t-statistik untuk menguji koefisien regresi parsial serta f-statistik untuk menguji keberartian pengaruh secara bersama-sama dengan level of significance 5%. Selain itu juga dilakukan uji asumsi klasik yang meliputi uji normalitas, uji multikolinearitas, uji heteroskedastisitas, dan uji autokolerasi. Berdasarkan karakteristik keseluruhan data, tidak terjadi penyimpangan asumsi klasik, hal ini menunjukkan bahwa data yang tersedia telah memenuhi syarat untuk menggunakan model persamaan regresi linier berganda. Dari hasil penelitian menunjukkan bahwa variabel independen yang terdiri dari CAR, NPL, ROA, LDR, dan FIRM SIZE tahun 2012-2014 secara simultan mempunyai pengaruh signifikan terhadap harga saham. Adapun secara parsial, variabel ROA berpengaruh signifikan positif. Sedangkan variabel CAR, NPL, LDR dan FIRM SIZE berpengaruh signifikan negatif terhadap harga saham. Hasil uji R square pada penelitian ini menunjukkan bahwa variabel CAR, NPL, ROA, LDR, dan FIRM SIZE memiliki pengaruh 20,7% terhadap harga saham. Kata Kunci : CAR, NPL, ROA, LDR, Firm Size, Harga Saham
A fast stroboscopic spectral method for rotating systems in numerical relativity
We present a numerical technique for solving evolution equations, as the wave
equation, in the description of rotating astrophysical compact objects in
comoving coordinates, which avoids the problems associated with the light
cylinder. The technique implements a fast spectral matching between two domains
in relative rotation: an inner spherical domain, comoving with the sources and
lying strictly inside the light cylinder, and an outer inertial spherical
shell. Even though the emphasis is placed on spectral techniques, the matching
is independent of the specific manner in which equations are solved inside each
domain, and can be adapted to different schemes. We illustrate the strategy
with some simple but representative examples.Comment: 16 pages, 15 figure
First upper limit analysis and results from LIGO science data: stochastic background
I describe analysis of correlations in the outputs of the three LIGO
interferometers from LIGO's first science run, held over 17 days in August and
September of 2002, and the resulting upper limit set on a stochastic background
of gravitational waves. By searching for cross-correlations between the LIGO
detectors in Livingston, LA and Hanford, WA, we are able to set a 90%
confidence level upper limit of h_{100}^2 Omega_0 < 23 +/- 4.6.Comment: 7 pages; 1 eps figures; proceeding from 2003 Edoardo Amaldi Meeting
on Gravitational Wave
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