Cosmic Mach Number as a Function of Overdensity and Galaxy Age

We carry out an extensive study of the cosmic Mach number (\mach) on scales of R=5, 10 and 20h^-1Mpc using an LCDM hydrodynamical simulation. We particularly put emphasis on the environmental dependence of \mach on overdensity, galaxy mass, and galaxy age. We start by discussing the difference in the resulting \mach according to different definitions of \mach and different methods of calculation. The simulated Mach numbers are slightly lower than the linear theory predictions even when a non-linear power spectrum was used in the calculation, reflecting the non-linear evolution in the simulation. We find that the observed \mach is higher than the simulated mean by more than 2-standard deviations, which suggests either that the Local Group is in a relatively low-density region or that the true value of \Omega_m is ~ 0.2, significantly lower than the simulated value of 0.37. We show from our simulation that the Mach number is a weakly decreasing function of overdensity. We also investigate the correlations between galaxy age, overdensity and \mach for two different samples of galaxies --- DWARFs and GIANTs. Older systems cluster in higher density regions with lower \mach, while younger ones tend to reside in lower density regions with larger \mach, as expected from the hierarchical structure formation scenario. However, for DWARFs, the correlation is weakened by the fact that some of the oldest DWARFs are left over in low-density regions during the structure formation history. For giant systems, one expects blue-selected samples to have higher \mach than red-selected ones. We briefly comment on the effect of the warm dark matter on the expected Mach number.Comment: 43 pages, including 15 figures. Accepted version in ApJ. Included correlation function of different samples of galaxies, and the cumulative number fraction distribution as a fcn. of overdensity. Reorganized figures and added some reference

Rewarming for accidental hypothermia in an urban medical center using extracorporeal membrane oxygenation.

BACKGROUND: Accidental hypothermia complicated by cardiac arrest carries a high mortality rate in urban areas. For moderate hypothermia cases conventional rewarming methods are usually adequate, however in severe cases extracorporeal membrane oxygenation (ECMO) is known to provide the most efficient rewarming with complete cardiopulmonary support. We report a case of severe hypothermia complicated by prolonged cardiac arrest successfully resuscitated using ECMO. CASE REPORT: A 45 year old female was brought to our emergency department with a core body temperature CONCLUSIONS: This case demonstrates the advantages of advanced internal rewarming techniques, such as ECMO, for quick and efficient rewarming of severely hypothermic patients. This case supports the use of ECMO in severely hypothermic patients as the standard of care

Anisotropic s-wave superconductivity in single crystals CaAlSi from penetration depth measurements

In- and out-of-plane London penetration depths were measured in single crystals CaAlSi (T_{c}=6.2 K and 7.3 K) using a tunnel-diode resonator. A full 3D BCS analysis of the superfluid density is consistent with a prolate spheroidal gap, with a weak-coupling BCS value in the ab-plane and stronger coupling along the c-axis. The gap anisotropy was found to significantly decrease for higher T_{c} samples.Comment: 4 page

Collimation of a spherical collisionless particles stream in Kerr space-time

We examine the propagation of collisionless particles emitted from a spherical shell to infinity. The number distribution at infinity, calculated as a function of the polar angle, exhibits a small deviation from uniformity. The number of particles moving from the polar region toward the equatorial plane is slightly larger than that of particles in the opposite direction, for an emission radius $> 4.5M$ in extreme Kerr space-time. This means that the black hole spin exerts an anti-collimation effect on the particles stream propagating along the rotation axis. We also confirm this property in the weak field limit. The quadrupole moment of the central object produces a force toward the equatorial plane. For a smaller emission radius $r<4.5M$, the absorption of particles into the black hole, the non-uniformity and/or the anisotropy of the emission distribution become much more important.Comment: 11 pages, 8 figures; accepted for publication in CQ

Bifurcation Phenomenon in a Spin Relaxation

Spin relaxation in a strong-coupling regime (with respect to the spin system) is investigated in detail based on the spin-boson model in a stochastic limit. We find a bifurcation phenomenon in temperature dependence of relaxation constants, which is never observed in the weak-coupling regime. We also discuss inequalities among the relaxation constants in our model and show the well-known relation 2\Gamma_T >= \Gamma_L, for example, for a wider parameter region than before.Comment: REVTeX4, 5 pages, 5 EPS figure

Transcriptional response of human mast cells stimulated via the FcεRI and identification of mast cells as a source of IL-11

BACKGROUND: In asthma and other allergic disorders, the activation of mast cells by IgE and antigen induces the cells to release histamine and other mediators of inflammation, as well as to produce certain cytokines and chemokines. To search for new mast cell products, we used complementary DNA microarrays to analyze gene expression in human umbilical cord blood-derived mast cells stimulated via the high-affinity IgE receptor (FcεRI). RESULTS: One to two hours after FcεRI-dependent stimulation, more than 2,400 genes (about half of which are of unknown function) exhibited 2–200 fold changes in expression. The transcriptional program included changes in the expression of IL-11 and at least 30 other cytokines and chemokines. Human mast cells secreted 130–529 pg of IL-11/10(6) cells by 6 h after stimulation with anti-IgE. CONCLUSION: Our initial analysis of the transcriptional program induced in in vitro-derived human mast cells stimulated via the FcεRI has identified many products that heretofore have not been associated with this cell type, but which may significantly influence mast cell function in IgE-associated host responses. We also have demonstrated that mast cells stimulated via the FcεRI can secrete IL-11. Based on the previously reported biological effects of IL-11, our results suggest that production of IL-11 may represent one link between IgE-dependent mast cell activation in subjects with allergic asthma and the development of a spectrum of structural changes in the airways of these individuals; such changes, collectively termed "airway remodeling," can constitute an important long term consequence of asthma

Complex sequencing rules of birdsong can be explained by simple hidden Markov processes

Complex sequencing rules observed in birdsongs provide an opportunity to investigate the neural mechanism for generating complex sequential behaviors. To relate the findings from studying birdsongs to other sequential behaviors, it is crucial to characterize the statistical properties of the sequencing rules in birdsongs. However, the properties of the sequencing rules in birdsongs have not yet been fully addressed. In this study, we investigate the statistical propertiesof the complex birdsong of the Bengalese finch (Lonchura striata var. domestica). Based on manual-annotated syllable sequences, we first show that there are significant higher-order context dependencies in Bengalese finch songs, that is, which syllable appears next depends on more than one previous syllable. This property is shared with other complex sequential behaviors. We then analyze acoustic features of the song and show that higher-order context dependencies can be explained using first-order hidden state transition dynamics with redundant hidden states. This model corresponds to hidden Markov models (HMMs), well known statistical models with a large range of application for time series modeling. The song annotation with these models with first-order hidden state dynamics agreed well with manual annotation, the score was comparable to that of a second-order HMM, and surpassed the zeroth-order model (the Gaussian mixture model (GMM)), which does not use context information. Our results imply that the hierarchical representation with hidden state dynamics may underlie the neural implementation for generating complex sequences with higher-order dependencies

Development of a novel method for visualizing restricted diffusion using subtraction of apparent diffusion coefficient values

In order to visualize restricted diffusion, the present study developed a novel method called 'apparent diffusion coefficient (ADC) subtraction method (ASM)' and compared it with diffusion kurtosis imaging (DKI). The diffusion-weighted images of physiological saline, in addtion to bio-phatoms of low cell density and the highest cell density were obtained using two sequences with different effective diffusion times. Then, the calculated ADC values were subtracted. The mean values and standard deviations (SD) of the ADC values of physiological saline, low cell density and the highest cell density phantoms were 2.95 +/- 0.08x10(-3), 1.90 +/- 0.35x10(-3) and 0.79 +/- 0.05x10(-3) mm(2)/sec, respectively. The mean kurtosis values and SD of DKI were 0.04 +/- 0.01, 0.44 +/- 0.13 and 1.27 +/- 0.03, respectively. The ASM and SD values were 0.25 +/- 0.20x10(4), 0.51 +/- 0.41x10(4) and 4.80 +/- 4.51x10(4) (sec/mm(2))(2), respectively. Using bio-phantoms, the present study demonstrated that DKI exhibits restricted diffusion in the extracellular space. Similarly, ASM may reflect the extent of restricted diffusion in the extracellular space

Time‐ and Frequency‐Domain Characteristics of Atrial Electrograms During Sinus Rhythm and Atrial Fibrillation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87064/1/j.1540-8167.2011.02022.x.pd