Physical properties and radius variations in the HAT-P-5 planetary system from simultaneous four-colour photometry

The radii of giant planets, as measured from transit observations, may vary with wavelength due to Rayleigh scattering or variations in opacity. Such an effect is predicted to be large enough to detect using ground-based observations at multiple wavelengths. We present defocussed photometry of a transit in the HAT-P-5 system, obtained simultaneously through Stromgren u, Gunn g and r, and Johnson I filters. Two more transit events were observed through a Gunn r filter. We detect a substantially larger planetary radius in u, but the effect is greater than predicted using theoretical model atmospheres of gaseous planets. This phenomenon is most likely to be due to systematic errors present in the u-band photometry, stemming from variations in the transparency of Earth's atmosphere at these short wavelengths. We use our data to calculate an improved orbital ephemeris and to refine the measured physical properties of the system. The planet HAT-P-5b has a mass of 1.06 +/- 0.11 +/- 0.01 Mjup and a radius of 1.252 +/- 0.042 +/- 0.008 Rjup (statistical and systematic errors respectively), making it slightly larger than expected according to standard models of coreless gas-giant planets. Its equilibrium temperature of 1517 +/- 29 K is within 60K of that of the extensively-studied planet HD 209458b.Comment: Version 2 corrects the accidental omission of one author in the arXiv metadata. Accepted for publication in MNRAS. 9 pages, 4 figures, 7 tables. The properties of HAT-P-5 have been added to the Transiting Extrasolar Planet Catalogue at http://www.astro.keele.ac.uk/~jkt/tepcat

Quantitative regional curvature analysis: Validation in animals of a method for assessing regional ventricular remodelling in ischemic heart disease

Recent studies show the impact of left ventricular shape and remodelling on patient prognosis. This mandates the development of quantitative methods for measuring shape. Quantitative regional curvature analysis (QRCA) was developed to quantitate shape on a regional basis so that measurements would not be constrained to assessment of only global shape and would, therefore be applicable to ischemic heart disease. To validate QRCA, eleven dogs were instrumented with coronary occluders and radiopaque markers on the epicardium and endocardium to provide fiducial points for calculation of shape, motion and thickening. These parameters were measured in the anterior and inferior walls, at rest, during left anterior descending occlusion and finally during circumflex occlusion. QRCA showed increased curvature (increased globularity) in each wall when thickening and motion deteriorated during occlusion. The most marked shape changes occurred in the inferior wall whereas the most marked deterioration of function was detected by wall thickening measurements of the anterior wall. Thus, QRCA detects regional ventricular shape disorders coincident with regional dysfunction induced by ischemia. These changes show regional heterogeneity and demonstrate the potential importance of this measurement as opposed to simple, global measures of shape. QRCA is, therefore, suitable for monitoring acute changes of shape that occur during acute ischemia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42545/1/10554_2005_Article_BF01798047.pd

AMP-activated protein kinase complexes containing the β2 regulatory subunit are upregulated during and contribute to adipogenesis

AMP-activated protein kinase (AMPK) is a heterotrimer of α catalytic and β and γ regulatory subunits that acts to regulate cellular and whole-body nutrient metabolism. The key role of AMPK in sensing energy status has led to significant interest in AMPK as a therapeutic target for dysfunctional metabolism in type 2 diabetes, insulin resistance and obesity. Despite the actions of AMPK in liver and skeletal muscle being extensively studied, the role of AMPK in adipose tissue and adipocytes remains less well characterised. Small molecules that selectively influence AMPK heterotrimers containing specific AMPKβ subunit isoforms have been developed, including MT47-100, which selectively inhibits complexes containing AMPKβ2. AMPKβ1 and AMPKβ2 are the principal AMPKβ subunit isoforms in rodent liver and skeletal muscle respectively, yet the contribution of specific AMPKβ isoforms to adipose tissue function, however, remains largely unknown. This study therefore sought to determine the contribution of AMPKβ subunit isoforms to adipocyte biology, focussing on adipogenesis. AMPKβ2 was the principal AMPKβ isoform in 3T3-L1 adipocytes, isolated rodent adipocytes and human subcutaneous adipose tissue, as assessed by the contribution to total cellular AMPK activity. Downregulation of AMPKβ2 with siRNA inhibited lipid accumulation, cellular adiponectin levels and adiponectin secretion during 3T3-L1 adipogenesis, whereas downregulation of AMPKβ1 had no effect. Incubation of 3T3-L1 cells with MT47-100 selectively inhibited AMPK complexes containing AMPKβ2 whilst simultaneously inhibiting cellular lipid accumulation as well as cellular levels and secretion of adiponectin. Taken together, these data indicate that increased expression of AMPKβ2 is an important feature of efficient adipogenesis

The effects of acute ischemia on the isovolumic index

The isovolumic index is the ratio of the duration of isovolumic contraction (IVC) and relaxation (IVR) divided by ejection time (ET), and has been proposed as a more sensitive descriptor of ventricular performance than the systolic time index, which ignores the period of isovolumic relaxation. To determine the effects of acute ischemia on these indices, IVC, IVR, and ET were measured in seven open-chest dogs instrumented with high-fidelity micromanometers and ultrasonic crystals and subjected to a 10-second period of coronary occlusion. Fractional shortening was significantly impaired (18.4 +/- 6.9% vs 1.9 +/- 7.3%, p p p p p < 0.05 cs control), though ET and the systolic time index were unchanged. Through incorporation of IVR, the isovolumic index was more sensitive to acute brief ischemia than the systolic time index.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27601/1/0000645.pd

Weather on the Nearest Brown Dwarfs: Resolved Simultaneous Multi-Wavelength Variability Monitoring of WISE J104915.57-531906.1AB

We present two epochs of MPG/ESO 2.2m GROND simultaneous 6-band ($r'i'z'JHK$) photometric monitoring of the closest known L/T transition brown dwarf binary WISE J104915.57-531906.1AB. We report here the first resolved variability monitoring of both the T0.5 and L7.5 components. We obtained 4 hours of focused observations on the night of UT 2013-04-22, as well as 4 hours of defocused (unresolved) observations on the night of UT 2013-04-16. We note a number of robust trends in our light curves. The $r'$ and $i'$ light curves appear to be anticorrelated with $z'$ and $H$ for the T0.5 component and in the unresolved lightcurve. In the defocused dataset, $J$ appears correlated with $z'$ and $H$ and anticorrelated with $r'$ and $i'$, while in the focused dataset we measure no variability for $J$ at the level of our photometric precision, likely due to evolving weather phenomena. In our focused T0.5 component lightcurve, the $K$ band lightcurve displays a significant phase offset relative to both $H$ and $z'$. We argue that the measured phase offsets are correlated with atmospheric pressure probed at each band, as estimated from 1D atmospheric models. We also report low-amplitude variability in $i'$ and $z'$ intrinsic to the L7.5 component.Comment: 14 pages, 5 figures, accepted to ApJ Letter

Pulmonary extraction of immunoreactive atrial natriuretic factor in dogs

A trial natriuretic factor (ANF) is a hormone predominantly secreted by the cardiac atria. It stimulates the kidney to produce natriuresis and diuresis, and vasodilates vascular smooth muscle. The half-life of the hormone is a few minutes, suggesting that breakdown occurs in many tissues.1 Significant extraction of ANF has been demonstrated across the capillary beds of liver, kidney and limb.1-3 Pulmonary extraction of the hormone has not been shown in dogs3 or man,1,2 however, even though rat lung homogenates destroy ANF4 and isolated rabbit lungs remove ANF,5 perhaps because blood samples in the in vivo studies were obtained from systemic arteries instead of pulmonary veins. If ANF is released into the left atrial cavity through the thebesian veins, systemic arterial sampling could underestimate pulmonary extraction of ANF. The purpose of this study was to determine whether ANF is extracted across the canine pulmonary perfusion bed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28077/1/0000522.pd

A Modality-Adaptive Method for Segmenting Brain Tumors and Organs-at-Risk in Radiation Therapy Planning

In this paper we present a method for simultaneously segmenting brain tumors and an extensive set of organs-at-risk for radiation therapy planning of glioblastomas. The method combines a contrast-adaptive generative model for whole-brain segmentation with a new spatial regularization model of tumor shape using convolutional restricted Boltzmann machines. We demonstrate experimentally that the method is able to adapt to image acquisitions that differ substantially from any available training data, ensuring its applicability across treatment sites; that its tumor segmentation accuracy is comparable to that of the current state of the art; and that it captures most organs-at-risk sufficiently well for radiation therapy planning purposes. The proposed method may be a valuable step towards automating the delineation of brain tumors and organs-at-risk in glioblastoma patients undergoing radiation therapy.Comment: corrected one referenc

The Structure, Anharmonic Vibrational Frequencies, and Intensities of NNHNN+

A semi-global potential energy surface (PES) and quartic force field (QFF) based on fitting high-level electronic structure energies are presented to describe the structures and spectroscopic properties of NNHNN+. The equilibrium structure of NNHNN+ is linear with the proton equidistant between the two nitrogen groups and thus of D(sub h) symmetry. Vibrational second-order perturbation theory (VPT2) calculations based on the QFF fails to describe the proton rattle motion, i.e., the antisymmetric proton stretch, due to the very flat nature of PES around the global minimum, but performs properly for other modes with sharper potential wells. Vibrational self-consistent field/virtual state configuration interaction (VSCF/VCI) calculations using a version of MULTIMODE without angular momentum terms successfully describe this motion and predict the fundamental to be at 759 cm(exp -1). This is in good agreement with the value of 746 cm(exp -1) from a fixed-node diffusion Monte Carlo calculation and the experimental Ar-tagged result of 743 cm(exp -1). Other VSCF/VCI energies are in good agreement with other experimentally reported ones. Both double-harmonic intensity and rigorous MULTIMODE intensity calculations show the proton transfer fundamental has a very strong intensity

Serial nuclear magnetic resonance imaging in acute myocardial infarction

Recent studies show that proton nuclear magnetic resonance (NMR) imaging can detect myocardial ischemia and acute myocardial infarction (AMI) in animal models1-3 and in humans.4-6 The area of AMI appears as increased signal intensity on the spin-echo NMR images and most likely reflects the regional edema associated with tissue necrosis.1 Thus, the time course of regional edema and the evolution of infarct healing may be revealed by serial NMR studies. In a recent canine study, Pflugfelder et al7 examined the time course of the increased NMR signal intensity associated with AMI. They found that the relative signal intensity increased between the day of AMI and 2 weeks after AMI and subsequently decreased by the 20th day. We examined the early time course of NMR changes in humans.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26729/1/0000279.pd