6,972 research outputs found
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The Fault Lines of Freedom: The Division and Devlopment of the Soviet Jewry Movement in the United States
On the morning of December 6, 1987, 250,000 people swarmed the U.S. National Mall.1 Soviet Premier Mikhail Gorbachev was to arrive the following day to meet with President Ronald Reagan for a new set of talks that marked a warming in the seemingly interminable Cold War. A future recipient of the Nobel Prize and Time’s person of the decade, Gorbachev had entranced the Western world as a great compromiser who had brought communism with a human face to the Eastern Bloc and the potential of world peace in the face of nuclear apocalypse.2 However, the quarter-million people on the frozen National Mall did not care about Gorbachev’s public image. They wanted him to make a commitment that the millions of Jewish people who had suffered decades of state-sponsored antiSemitism in the U.S.S.R. would be granted increased religious freedom and the right to emigrate. Chants of “Let my people go!” echoed throughout the National Mall over the course of the day, a phrase that had been the clarion call for many of these people for almost thirty years
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Alpha1 -adrenergic stimulation selectively enhances endothelium-mediated vasodilation in rat cremaster arteries.
We have systematically investigated how vascular smooth muscle α1 -adrenoceptor activation impacts endothelium-mediated vasodilation in isolated, myogenically active, rat cremaster muscle 1A arteries. Cannulated cremaster arteries were pressurized intraluminally to 70 mmHg to induce myogenic tone, and exposed to vasoactive agents via bath superfusion at 34°C. Smooth muscle membrane potential was measured via sharp microelectrode recordings in pressurized, myogenic arteries. The α1 -adrenergic agonist phenylephrine (25-100 nmol/L) produced further constriction of myogenic arteries, but did not alter the vasorelaxant responses to acetylcholine (0.3 μmol/L), SKA-31 (an activator of endothelial Ca2+ -dependent K+ channels) (3 μmol/L) or sodium nitroprusside (10 μmol/L). Exposure to 0.25-1 μmol/L phenylephrine or 1 μmol/L norepinephrine generated more robust constrictions, and also enhanced the vasodilations evoked by acetylcholine and SKA-31, but not by sodium nitroprusside. In contrast, the thromboxane receptor agonist U46619 (250 nmol/L) dampened responses to all three vasodilators. Phenylephrine exposure depolarized myogenic arteries, and mimicking this effect with 4-aminopyridine (1 mmol/L) was sufficient to augment the SKA-31-evoked vasodilation. Inhibition of L-type Ca2+ channels by 1 μmol/L nifedipine decreased myogenic tone, phenylephrine-induced constriction and prevented α1 -adrenergic enhancement of endothelium-evoked vasodilation; these latter deficits were overcome by exposure to 3 and 10 μmol/L phenylephrine. Mechanistically, augmentation of ACh-evoked dilation by phenylephrine was dampened by eNOS inhibition and abolished by blockade of endothelial KCa channels. Collectively, these data suggest that increasing α1 -adrenoceptor activation beyond a threshold level augments endothelium-evoked vasodilation, likely by triggering transcellular signaling between smooth muscle and the endothelium. Physiologically, this negative feedback process may serve as a "brake" to limit the extent of vasoconstriction in the skeletal microcirculation evoked by the elevated sympathetic tone
Velocity-resolved observations of water in Comet Halley
High resolution (lambda/delta lambda approx. = 3 x 10 to the 5th power) near-infrared observations of H2O emission from Comet Halley were acquired at the time of maximum post-perihelion geocentric Doppler shift. The observed widths and absolute positions of the H2O line profiles reveal characteristics of the molecular velocity field in the coma. These results support H2O outflow from a Sun-lit hemisphere or the entire nucleus, but not from a single, narrow jet emanating from the nucleus. The measured pre- and post-perihelion outflow velocities were 0.9 + or - 0.2 and 1.4 + or - 0.2 km/s, respectively. Temporal variations in the kinematic properties of the outflow were inferred from changes in the spectral line shapes. These results are consistent with the release of H2O into the coma from multiple jets
Examining Processes of Change for Acceptance and Commitment Therapy and Cognitive Behavioral Therapy Self-Help Books With Depressed College Students
Given the prevalence of depression, it is worthwhile to consider a variety of treatment approaches to reach as many sufferers as possible, including highly accessible formats such as self-help books. Books based in acceptance and commitment therapy (ACT) and cognitive behavioral therapy (CBT) propose to treat depression through distinct processes of change, though the degree to which these treatments are distinguishable in this format is unclear. Furthermore, it is possible that some individuals may respond better to therapeutic processes from one approach over the other based on personal preferences. We tested the effects of ACT and CBT self-help books on processes of change in a sample of 139 depressed college students in which some participants were given a choice of treatment and others were randomized. Cognitive fusion, which improved better in the ACT group, was the only process of change that distinguished the two treatments. Additionally, early improvements in cognitive fusion were associated with less depression-related stigma at posttreatment. Lastly, randomization, instead of choosing a treatment, led to greater improvements in almost all processes of change. We discuss how these findings inform personalized care, tangible differences between ACT and CBT, and effective practices for treating depression at large scale
FeH Absorption in the Near-Infrared Spectra of Late M and L Dwarfs
We present medium-resolution z-, J-, and H-band spectra of four late-type
dwarfs with spectral types ranging from M8 to L7.5. In an attempt to determine
the origin of numerous weak absorption features throughout their near-infrared
spectra, and motivated by the recent tentative identification of the E 4\Pi- A
^4\Pi system of FeH near 1.6 microns in umbral and cool star spectra, we have
compared the dwarf spectra to a laboratory FeH emission spectrum. We have
identified nearly 100 FeH absorption features in the z-, J-, and H-band spectra
of the dwarfs. In particular, we have identified 34 features which dominate the
appearance of the H-band spectra of the dwarfs and which appear in the
laboratory FeH spectrum. Finally, all of the features are either weaker or
absent in the spectrum of the L7.5 dwarf which is consistent with the weakening
of the known FeH bandheads in the spectra of the latest L dwarfs.Comment: accepted by Ap
Phase and frequency entrainment in locally coupled phase oscillators with repulsive interactions
Recent experiments in one and two-dimensional microfluidic arrays of droplets
containing Belousov -Zhabotinsky reactants show a rich variety of spatial
patterns [J. Phys. Chem. Lett. 1, 1241-1246 (2010)]. The dominant coupling
between these droplets is inhibitory. Motivated by this experimental system, we
study repulsively coupled Kuramoto oscillators with nearest neighbor
interactions, on a linear chain as well as a ring in one dimension, and on a
triangular lattice in two dimensions. In one dimension, we show using linear
stability analysis as well as numerical study, that the stable phase patterns
depend on the geometry of the lattice. We show that a transition to the ordered
state does not exist in the thermodynamic limit. In two dimensions, we show
that the geometry of the lattice constrains the phase difference between two
neighbouring oscillators to 120 degrees. We report the existence of domains
with either clockwise or anti-clockwise helicity, leading to defects in the
lattice. We study the time dependence of these domains and show that at large
coupling strengths, the domains freeze due to frequency synchronization.
Signatures of the above phenomena can be seen in the spatial correlation
functions.Comment: 9 pages, 12 figure
Evaluating the Effects of Guided Coaching Calls on Engagement and Outcomes for Online Acceptance and Commitment Therapy
Previous research indicates mixed results for guided support with interventions. The current secondary analysis evaluated the effects of phone coaching from a dismantling trial of online acceptance and commitment therapy (ACT) in a sample of 136 distressed college students randomized to one of three versions of an ACT website. Participants were randomized to receive email prompts alone (non-coaching condition) or email plus phone coaching (coaching condition). Results indicated no differences between the coaching and non-coaching conditions on program engagement, program satisfaction, mental health outcomes, and almost all psychological flexibility processes. However, participants in the coaching condition reported stronger pre- to posttreatment improvements in psychological inflexibility than the non-coaching condition. This effect was moderated by ACT component condition, with larger pre- to posttreatment effects from coaching on psychological inflexibility in the values/committed action condition and weaker improvements from coaching in the acceptance/defusion condition. Overall, results indicate online self-guided ACT interventions with email prompts are sufficient for addressing college student mental health and that phone coaching provided minimal additional benefit
Exotic torus manifolds and equivariant smooth structures on quasitoric manifolds
In 2006 Masuda and Suh asked if two compact non-singular toric varieties
having isomorphic cohomology rings are homeomorphic. In the first part of this
paper we discuss this question for topological generalizations of toric
varieties, so-called torus manifolds. For example we show that there are
homotopy equivalent torus manifolds which are not homeomorphic. Moreover, we
characterize those groups which appear as the fundamental groups of locally
standard torus manifolds.
In the second part we give a classification of quasitoric manifolds and
certain six-dimensional torus manifolds up to equivariant diffeomorphism.
In the third part we enumerate the number of conjugacy classes of tori in the
diffeomorphism group of torus manifolds. For torus manifolds of dimension
greater than six there are always infinitely many conjugacy classes. We give
examples which show that this does not hold for six-dimensional torus
manifolds.Comment: 21 pages, 2 figures, results about quasitoric manifolds adde
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