206,210 research outputs found
CCD PHOTOMETRY OF RR LYRAE STARS IN M5 AS A TEST FOR THE PULSATIONAL SCENARIO
In this paper we present new CCD investigations of RR Lyrae pulsators in the
Oo.I globular cluster M5. B V curves of light for 15 RR Lyrae are presented.
With the addition of further 11 curves of light by Storm, Carney and Beck
(1991) one is dealing with a sample of 26 well studied cluster pulsators whose
properties have been implemented with similar data for RR Lyrae in clusters M3,
M15, M68 to allow a comparison with the theoretical scenario recently presented
by Bono and Stellingwerf (1994). On this basis, we discuss the distribution of
stars in the period amplitude diagram, disclosing a substantial reduction of
Sandage's period shift. We suggest that theoretical constraints concerning
periods and amplitudes could allow information on masses and luminosity of the
pulsators directly from Bailey's diagram only. Static temperatures have been
derived for all stars in the sample, discussing the dependence on the
temperature of the observed pulsational properties.Comment: postscript file of 17 pages of text plus 7 figures and 2 tables. For
any problem please write to [email protected]
Overexpression of the type 1 adenylyl cyclase in the forebrain leads to deficits of behavioral inhibition
The type 1 adenylyl cyclase (AC1) is an activity-dependent, calcium-stimulated adenylyl cyclase expressed in the nervous system that is implicated in memory formation. We examined the locomotor activity, and impulsive and social behaviors of AC1+ mice, a transgenic mouse strain overexpressing AC1 in the forebrain. Here we report that AC1+ mice exhibit hyperactive behaviors and demonstrate increased impulsivity and reduced sociability. In contrast, AC1 and AC8 double knock-out mice are hypoactive, and exhibit increased sociability and reduced impulsivity. Interestingly, the hyperactivity of AC1+ mice can be corrected by valproate, a mood-stabilizing drug. These data indicate that increased expression of AC1 in the forebrain leads to deficits in behavioral inhibition
A quantitative assessment of empirical magnetic field models at geosynchronous orbit during magnetic storms
[1] We evaluate the performance of recent empirical magnetic field models (Tsyganenko, 1996, 2002a, 2002b; Tsyganenko and Sitnov, 2005, hereafter referred to as T96, T02 and TS05, respectively) during magnetic storm times including both pre- and post-storm intervals. The model outputs are compared with GOES observations of the magnetic field at geosynchronous orbit. In the case of a major magnetic storm, the T96 and T02 models predict anomalously strong negative Bz at geostationary orbit on the nightside due to input values exceeding the model limits, whereas a comprehensive magnetic field data survey using GOES does not support that prediction. On the basis of additional comparisons using 52 storm events, we discuss the strengths and limitations of each model. Furthermore, we quantify the performance of individual models at predicting geostationary magnetic fields as a function of local time, Dst, and storm phase. Compared to the earlier models (T96 and T02), the most recent storm-time model (TS05) has the best overall performance across the entire range of local times, storm levels, and storm phases at geostationary orbit. The field residuals between TS05 and GOES are small (≤3 nT) compared to the intrinsic short time-scale magnetic variability of the geostationary environment even during non-storm conditions (∼24 nT). Finally, we demonstrate how field model errors may affect radiation belt studies when estimating electron phase space density
Baade-Wesselink distances to Galactic and Magellanic Cloud Cepheids and the effect of metallicity
(abridged) The aim of this paper is to investigate the metallicity dependence
of the PL relation in V and K, based on a sample of 128 Galactic, 36 LMC, and 6
SMC Cepheids with individual Baade-Wesselink (BW) distances and individually
determined metallicities from high-resolution spectroscopy. The p-relation
finally adopted is 1.50 -0.24log P. The slope of this relation is based on the
condition that the distance to the LMC does not depend on period or (V-K)
colour and that the slope of the PL relation based on the BW distances agrees
with that based on apparent magnitude. The zero point of the relation is tight
to the Cepheids with HST and revised Hipparcos parallaxes as well as to
Cepheids in clusters. The slope of the Galactic and LMC K-band relation
formally agrees within the errors, and combining all Cepheids (including the
SMC) results in a negligible metallicity dependence. A similar conclusion is
found for the reddening-free Wesenheit relation. In the V-band the situation is
more complex. The slope of the LMC and the Galactic PL relation differ at the
3sigma level. Combining the sample nevertheless results in a metallicity term
significant at the 2sigma level. The details of the comparison of BW-based
distances and Cepheids with HST and revised Hipparcos parallaxes also play a
role. The method used by Storm et al. would lead to larger DM of 18.37 and
18.81 for the LMC and SMC, respectively. The LMC DM is shorter than the
currently accepted value, which is in the range 18.42 to 18.55 (Walker 2012),
and it is speculated that the p-factor may depend on metallicity.Comment: Accepted for A&
Planning for climate change by Queensland coastal councils
The Queensland Coastal Plan requires councils to prepare coastal hazard adaptation plans for those parts of their urban areas at risk from a projected sea level rise of 80cm by 2100. This paper reviews adaptation actions in climate change strategies prepared by four urban Queensland coastal councils (e.g. Cairns, Gold Coast, Redland, and Sunshine Coast), and one community-based climate adaptation action plan for Bribie Island in Moreton Bay. The actions in these climate change plans are analysed for their adaptive response categories: Emphasising Nature, Emphasising Development and Managed Nature (Vasey-Ellis, 2009),
along with Council Governance of climate change, and Emphasising Communities. Climate change planning and infrastructure responses by Queensland coastal councils mainly focus on protecting coastal development from erosion and other climate hazards, and building community resilience, supplemented by ‘soft’ environmental actions protecting nature. While some climate plans included actions for shoreline erosion, coastal inundation, and storm
surges, only one addressed sea level rise impacts on buildings and heritage (i.e. Redland)
Cross-Talk-Free Multi-Color STORM Imaging Using a Single Fluorophore
Multi-color stochastic optical reconstruction microscopy (STORM) is routinely performed; however, the various approaches for achieving multiple colors have important caveats. Color cross-talk, limited availability of spectrally distinct fluorophores with optimal brightness and duty cycle, incompatibility of imaging buffers for different fluorophores, and chromatic aberrations impact the spatial resolution and ultimately the number of colors that can be achieved. We overcome these complexities and develop a simple approach for multi-color STORM imaging using a single fluorophore and sequential labelling. In addition, we present a simple and versatile method to locate the same region of interest on different days and even on different microscopes. In combination, these approaches enable cross-talk-free multi-color imaging of sub-cellular structures.Peer ReviewedPostprint (published version
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