31 research outputs found
Автоматизация внутреннего документооборота предприятия
Применение ERP-системы для автоматизации внутренних процессов и оценивания
результатов деятельности предприятияApplication of an ERP system for automating internal processes and evaluating the
results of an enterprise's activitie
Are Dwarf Galaxies Dominated by Dark Matter?
Mass models for a sample of 18 late-type dwarf and low surface brightness
galaxies show that in almost all cases the contribution of the stellar disks to
the rotation curves can be scaled to explain most of the observed rotation
curves out to two or three disk scale lengths. The concept of a maximum disk,
therefore, appears to work as well for these late-type dwarf galaxies as it
does for spiral galaxies. Some of the mass-to-light ratios required in our
maximum disk fits are high, however, up to about 15 in the R-band, with the
highest values occurring in galaxies with the lowest surface brightnesses.
Equally well-fitting mass models can be obtained with much lower mass-to-light
ratios. Regardless of the actual contribution of the stellar disk, the fact
that the maximum disk can explain the inner parts of the observed rotation
curves highlights the similarity in shapes of the rotation curve of the stellar
disk and the observed rotation curve. This similarity implies that the
distribution of the total mass density is closely coupled to that of the
luminous mass density in the inner parts of late-type dwarf galaxies.Comment: Accepted for publication in the Astrophysical Journa
Disentangling Baryons and Dark Matter in the Spiral Gravitational Lens B1933+503
Measuring the relative mass contributions of luminous and dark matter in
spiral galaxies is important for understanding their formation and evolution.
The combination of a galaxy rotation curve and strong lensing is a powerful way
to break the disk-halo degeneracy that is inherent in each of the methods
individually. We present an analysis of the 10-image radio spiral lens
B1933+503 at z_l=0.755, incorporating (1) new global VLBI observations, (2) new
adaptive-optics assisted K-band imaging, (3) new spectroscopic observations for
the lens galaxy rotation curve and the source redshift. We construct a
three-dimensionally axisymmetric mass distribution with 3 components: an
exponential profile for the disk, a point mass for the bulge, and an NFW
profile for the halo. The mass model is simultaneously fitted to the kinematics
and the lensing data. The NFW halo needs to be oblate with a flattening of
a/c=0.33^{+0.07}_{-0.05} to be consistent with the radio data. This suggests
that baryons are effective at making the halos oblate near the center. The
lensing and kinematics analysis probe the inner ~10 kpc of the galaxy, and we
obtain a lower limit on the halo scale radius of 16 kpc (95% CI). The dark
matter mass fraction inside a sphere with a radius of 2.2 disk scale lengths is
f_{DM,2.2}=0.43^{+0.10}_{-0.09}. The contribution of the disk to the total
circular velocity at 2.2 disk scale lengths is 0.76^{+0.05}_{-0.06}, suggesting
that the disk is marginally submaximal. The stellar mass of the disk from our
modeling is log_{10}(M_{*}/M_{sun}) = 11.06^{+0.09}_{-0.11} assuming that the
cold gas contributes ~20% to the total disk mass. In comparison to the stellar
masses estimated from stellar population synthesis models, the stellar initial
mass function of Chabrier is preferred to that of Salpeter by a probability
factor of 7.2.Comment: 16 pages, 13 figures, minor revisions based on referee's comments,
accepted for publication in Ap
The SWELLS survey. II. Breaking the disk-halo degeneracy in the spiral galaxy gravitational lens SDSS J2141-0001
The degeneracy among the disk, bulge and halo contributions to galaxy
rotation curves prevents an understanding of the distribution of baryons and
dark matter in disk galaxies. In an attempt to break this degeneracy, we
present an analysis of the spiral galaxy strong gravitational lens SDSS
J2141-0001, discovered as part of the SLACS survey. We present new Hubble Space
Telescope multicolor imaging, gas and stellar kinematics data derived from
long-slit spectroscopy, and K-band LGS adaptive optics imaging, both from the
Keck telescopes. We model the galaxy as a sum of concentric axisymmetric bulge,
disk and halo components and infer the contribution of each component, using
information from gravitational lensing and gas kinematics. This analysis yields
a best-fitting total (disk plus bulge) stellar mass of log_{10}(Mstar/Msun) =
10.99(+0.11,-0.25). The photometric data combined with stellar population
synthesis models yield log_{10}(Mstar/Msun) = 10.97\pm0.07, and 11.21\pm0.07
for the Chabrier and Salpeter IMFs, respectively. Accounting for the expected
gas fraction of \simeq 20% reduces the lensing plus kinematics stellar mass by
0.10\pm0.05 dex, resulting in a Bayes factor of 11.9 in favor of a Chabrier
IMF. The dark matter halo is roughly spherical, with minor to major axis ratio
q_{halo}=0.91(+0.15,-0.13). The dark matter halo has a maximum circular
velocity of V_{max}=276(+17,-18) km/s, and a central density parameter of
log_{10}\Delta_{V/2}=5.9(+0.9,-0.5). This is higher than predicted for
uncontracted dark matter haloes in LCDM cosmologies, log_{10}\Delta_{V/2}=5.2,
suggesting that either the halo has contracted in response to galaxy formation,
or that the halo has a higher than average concentration. At 2.2 disk scale
lengths the dark matter fraction is f_{DM}=0.55(+0.20,-0.15), suggesting that
SDSS J2141-0001 is sub-maximal.Comment: 24 pages, 20 figures, accepted to MNRAS, minor change
The il-6/gp130 signaling pathway in myeloid cells modulates the inflammatory response during sepsis
DataSheet1_Validating expression of beta cell maturation-associated genes in human pancreas development.PDF
The identification of genes associated with human pancreatic beta cell maturation could stimulate a better understanding of normal human islet development and function, be informative for improving stem cell-derived islet (SC-islet) differentiation, and facilitate the sorting of more mature beta cells from a pool of differentiated cells. While several candidate factors to mark beta cell maturation have been identified, much of the data supporting these markers come from animal models or differentiated SC-islets. One such marker is Urocortin-3 (UCN3). In this study, we provide evidence that UCN3 is expressed in human fetal islets well before the acquisition of functional maturation. When SC-islets expressing significant levels of UCN3 were generated, the cells did not exhibit glucose-stimulated insulin secretion, indicating that UCN3 expression is not correlated with functional maturation in these cells. We utilized our tissue bank and SC-islet resources to test an array of other candidate maturation-associated genes, and identified CHGB, G6PC2, FAM159B, GLUT1, IAPP and ENTPD3 as markers with expression patterns that correlate developmentally with the onset of functional maturation in human beta cells. We also find that human beta cell expression of ERO1LB, HDAC9, KLF9, and ZNT8 does not change between fetal and adult stages.</p
Outcomes Associated With Common and Immigrant-Group-Specific Responses to Intimate Terrorism
Psychological Aggression in Dating Relationships: Predictive Models for Males and Females
Used variables related to the use of physical aggression in dating relationships and conflict management strategies to predict the use of psychological aggression in courtship. Participants were 193 females and 194 males (aged 18-20 yrs) from 2 small universities. Individual factors (i.e., variables associated with threat susceptibility) and situational variables (i.e., relationship length and emotional commitment to the partner, conflict management strategies, and weekly alcohol intake) were proposed to be important in the prediction of male\u27s and female\u27s use of psychological aggression with their partners. Findings suggest that these variables successfully predict the use of psychologically aggressive acts in courtship. Further, interactions with sex of participant suggest that different variables are important in the prediction of males\u27 and females\u27 use of such negative behaviors. These differences in the relationships between the predictors and criteria for males and females suggest not only divergent predictive models but also potential motivational differences in the employment of such tactics