2,159 research outputs found
Microwave-assisted synthesis of 3-aminobenzo[b]thiophene scaffolds for the preparation of kinase inhibitors
Microwave irradiation of 2-halobenzonitriles and methyl thioglycolate in the presence of triethylamine in DMSO at 130 °C provides rapid access to 3-aminobenzo[b]thiophenes in 58–96% yield. This transformation has been applied in the synthesis of the thieno[2,3-b]pyridine core motif of LIMK1 inhibitors, the benzo[4,5]thieno[3,2-e][1,4]diazepin-5(2H)-one scaffold of MK2 inhibitors and a benzo[4,5]thieno[3,2-d]pyrimidin-4-one inhibitor of the PIM kinases
Economic Change and Change in Well-Being in the Czech Republic, with Comparisons to Married Women in the United States
Examines the effects of economic change on individual well-being for a panel of married Czech women compared with a US sample from IA (N = 192 & 386, respectively, in 1990/91). Questionnaire data show that respondents who were forced to make economic adjustments reducing their standard of living also reported increased health problems & depressive symptoms. Contrary to some US findings the relationship between economic adjustments & change in depressive symptoms was strongest among those who reported having the strongest sense of personal control (mastery) & the highest perceived social support. Compared with the US sample, married Czech women reported more depressive symptoms, had more health problems, & were lower in feelings of mastery. In addition, Czech women recorded significantly stronger paths linking education to changes in health conditions & depressive symptoms, whereas US women had significantly stronger paths linking actual economic conditions to subsequent economic adjustments. Data suggest that the US stress-distress model applies in the Czech Republic as well, but further understanding of the differentiated role of social support & mastery for Czech & US women is necessray to more completely interpret the observed interactions
Lower bounds for the first eigenvalue of the magnetic Laplacian
We consider a Riemannian cylinder endowed with a closed potential 1-form A
and study the magnetic Laplacian with magnetic Neumann boundary conditions
associated with those data. We establish a sharp lower bound for the first
eigenvalue and show that the equality characterizes the situation where the
metric is a product. We then look at the case of a planar domain bounded by two
closed curves and obtain an explicit lower bound in terms of the geometry of
the domain. We finally discuss sharpness of this last estimate.Comment: Replaces in part arXiv:1611.0193
If cooperation is likely punish mildly: Insights from economic experiments based on the snowdrift game
Punishment may deter antisocial behavior. Yet to punish is costly, and the
costs often do not offset the gains that are due to elevated levels of
cooperation. However, the effectiveness of punishment depends not only on how
costly it is, but also on the circumstances defining the social dilemma. Using
the snowdrift game as the basis, we have conducted a series of economic
experiments to determine whether severe punishment is more effective than mild
punishment. We have observed that severe punishment is not necessarily more
effective, even if the cost of punishment is identical in both cases. The
benefits of severe punishment become evident only under extremely adverse
conditions, when to cooperate is highly improbable in the absence of sanctions.
If cooperation is likely, mild punishment is not less effective and leads to
higher average payoffs, and is thus the much preferred alternative. Presented
results suggest that the positive effects of punishment stem not only from
imposed fines, but may also have a psychological background. Small fines can do
wonders in motivating us to chose cooperation over defection, but without the
paralyzing effect that may be brought about by large fines. The later should be
utilized only when absolutely necessary.Comment: 15 pages, 6 figures; accepted for publication in PLoS ON
Arteriography during ex vivo renal perfusion A complication
A case of bilateral renal-cell carcinoma unsuccessfully treated with bench surgery is reported. The reason for failure was apparently the toxicity of the contrast media used during the ex vivo arteriographic studies. © 1973
Continuum removal in H\alpha\ extragalactic measurements
We point out an important source of error in measurements of extragalactic
H-alpha emission and suggest ways to reduce it.
The H-alpha line, used for estimating star formation rates, is commonly
measured by imaging in a narrow band and a wide band, both which include the
line. The image analysis relies on the accurate removal of the underlying
continuum. We discuss in detail the derivation of the emission line's
equivalent width and flux for extragalactic extended sources, and the required
photometric calibrations. We describe commonly used continuum-subtraction
procedures, and discuss the uncertainties that they introduce.
Specifically, we analyse errors introduced by colour effects. We show that
the errors in the measured H-alpha equivalent width induced by colour effects
can lead to underestimates as large as 40% and overestimates as large as 10%,
depending on the underlying galaxy's stellar population and the
continuum-subtraction procedure used. We also show that these errors may lead
to biases in results of surveys, and to the underestimation of the cosmic star
formation rate at low redshifts (the low z points in the Madau plot). We
suggest a method to significantly reduce these errors using a single colour
measurement.Comment: 8 pages, 3 figures, MNRAS in pres
Dynamical robustness of biological networks with hierarchical distribution of time scales
We propose the concepts of distributed robustness and r-robustness, well
adapted to functional genetics. Then we discuss the robustness of the
relaxation time using a chemical reaction description of genetic and signalling
networks. First, we obtain the following result for linear networks: for large
multiscale systems with hierarchical distribution of time scales the variance
of the inverse relaxation time (as well as the variance of the stationary rate)
is much lower than the variance of the separate constants. Moreover, it can
tend to 0 faster than 1/n, where n is the number of reactions. We argue that
similar phenomena are valid in the nonlinear case as well. As a numerical
illustration we use a model of signalling network that can be applied to
important transcription factors such as NFkB
An Evolutionary Sequence of Expanding Hydrogen Shells in Galaxy Discs
Large HI shells, with diameters of hundreds of pc and expansion velocities of
10-20kms-1 are well observed features of local gas rich galaxies. These shells
could well be predicted as a result of the impact of OB associations on the
ISM, but doubt has been cast on this scenario by the apparent absence of OB
stars close to the centres of a large fraction of these shells in recent
observations of the SMC. Using Fabry-Perot scanned Halpha emission line mapping
of nearby galaxy discs we have detected, in all the HII regions where the
observations yield sufficient angular resolution and S:N ratio, dominant Halpha
shells with radii a few tens of pc, expanding at velocities of 50-100kms-1. We
have applied a simple dynamically consistent framework in which we can
extrapolate the properties of the observed Halpha shells to a few 10^7yr after
the formation of the OB stars. The framework includes the dynamical inputs of
both winds and SNe on the surrounding ISM. The results give quantitative
statistical support to the hypothesis that the Halpha emitting shells are
generic progenitors of the HI shells. During the time taken for an expanding
shell to reach the size of a typical HI shell, the OB association may well lose
its most luminous stars so the absence of such stars near the centres of many
of the HI shells is well explained in this scenario.Comment: 8 pages, 4 figures, accepted for publication in Astronomy and
Astrophysic
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