Pressure of the Popular: Presidential Prestige and the High Court

Review of Popular Justice: Presidential Prestige and Executive Success in the Supreme Court. By Jeff Yates. State University of New York Press, 2002. 131 pages. $17.95

Pressure of the Popular: Presidential Prestige and the High Court

Review of Popular Justice: Presidential Prestige and Executive Success in the Supreme Court. By Jeff Yates. State University of New York Press, 2002. 131 pages. $17.95

An X-Ray Spectroscopic Study of the SMC X-1/Sk 160 System

We have investigated the composition and distribution of the wind of Sk 160, the supergiant companion of the X-ray star SMC X-1, by comparing an X-ray spectrum of the source, obtained with the ASCA observatory, during an eclipse with the computed spectra of reprocessed radiation from circumstellar matter with various density distributions. We show that the metal abundance in the wind of Sk 160 is no greater than a few tenths of solar, as has been determined for other objects in the Magellanic Clouds. We also show that the observed X-ray spectrum is not consistent with the density distributions of circumstellar matter of the spherically symmetric form derived for line-driven winds, nor with the density distribution derived from a hydrodynamic simulation of the X-ray perturbed and line-driven wind by Blondin & Woo (1995).Comment: 35 pages including 16 figures, uses AASTeX v5.0.2, accepted to Ap

Binding, thermodynamics, and selectivity of a non-peptide antagonist to the melanocortin-4 receptor

The melanocortin-4 receptor (MC4R) is a potential drug target for treatment of obesity, anxiety, depression, and sexual dysfunction. Crystal structures for MC4R are not yet available, which has hindered successful structure-based drug design. Using microsecond-scale molecular-dynamics simulations, we have investigated selective binding of the non-peptide antagonist MCL0129 to a homology model of human MC4R (hMC4R). This approach revealed that, at the end of a multi-step binding process, MCL0129 spontaneously adopts a binding mode in which it blocks the agonistic-binding site. This binding mode was confirmed in subsequent metadynamics simulations, which gave an affinity for human hMC4R that matches the experimentally determined value. Extending our simulations of MCL0129 binding to hMC1R and hMC3R, we find that receptor subtype selectivity for hMC4R depends on few amino acids located in various structural elements of the receptor. These insights may support rational drug design targeting the melanocortin systems

Facile C_sp²-C_sp² bond cleavage in oxalic acid-derived radicals

Oxalate decarboxylase (OxDC) catalyzes the Mn-dependent conversion of the oxalate monoanion into CO2 and formate. Many questions remain about the catalytic mechanism of OxDC although it has been proposed that the reaction proceeds via substrate-based radical intermediates. Using coupled cluster theory combined with implicit solvation models we have examined the effects of radical formation on the structure and reactivity of oxalic acid-derived radicals in aqueous solution. Our results show that the calculated solution-phase free-energy barrier for C–C bond cleavage to form CO2 is decreased from 34.2 kcal/mol for oxalic acid to only 9.3 kcal/mol and a maximum of 3.5 kcal/mol for the cationic and neutral oxalic acid-derived radicals, respectively. These studies also show that the C–C σ bonding orbital of the radical cation contains only a single electron, giving rise to an elongated C–C bond distance of 1.7 Å; a similar lengthening of the C–C bond is not observed for the neutral radical. This study provides new chemical insights into the structure and stability of plausible intermediates in the catalytic mechanism of OxDC, and suggests that removal of an electron to form a radical (with or without the concomitant loss of a proton) may be a general strategy for cleaving the unreactive C–C bonds between adjacent sp2-hybridized carbon atoms

RASSF1A and the rs2073498 Cancer Associated SNP

RASSF1A is one of the most frequently inactivated tumor suppressors yet identified in human cancer. It is pro-apoptotic and appears to function as a scaffolding protein that interacts with a variety of other tumor suppressors to modulate their function. It can also complex with the Ras oncoprotein and may serve to integrate pro-growth and pro-death signaling pathways. A SNP has been identified that is present in approximately 29% of European populations [rs2073498, A(133)S]. Several studies have now presented evidence that this SNP is associated with an enhanced risk of developing breast cancer. We have used a proteomics based approach to identify multiple differences in the pattern of protein/protein interactions mediated by the wild type compared to the SNP variant protein. We have also identified a significant difference in biological activity between wild type and SNP variant protein. However, we have found only a very modest association of the SNP with breast cancer predisposition

Testing Hydrodynamic Models of LMC X-4 with UV and X-ray Spectra

We compare the predictions of hydrodynamic models of the LMC X-4 X-ray binary system with observations of UV P Cygni lines with the GHRS and STIS spectrographs on the Hubble Space Telescope. The hydrodynamic model determines density and velocity fields of the stellar wind, wind-compressed disk, accretion stream, Keplerian accretion disk, and accretion disk wind. We use a Monte Carlo code to determine the UV P Cygni line profiles by simulating the radiative transfer of UV photons that originate on the star and are scattered in the wind. The qualitative orbital variation predicted is similar to that observed, although the model fails to reproduce the strong orbital asymmetry (the observed absorption is strongest for phi>0.5). The model predicts a mid-eclipse X-ray spectrum, due almost entirely to Compton scattering, with a factor 4 less flux than observed with ASCA. We discuss how the model may need to be altered to explain the spectral variability of the system.Comment: 11 figures, accepted by Ap

D e t e c t io n A n d R e c o g n it io n O f N o r t h A t l a n t ic R ig h t W h a l e C o n t a c t C a l l s In T h e P r e s e n c e O f A m b ie n t N o ise

a b s t r a c t The problem of detection and recognition of contact calls produced by North Atlantic right whales, Eubalaena glacialis, is considered. A proposed solution is based on a multiple-stage hypothesis-testing technique involving a spectrogram-based detector, spectrogram testing, and feature vector testing algorithms. Results show that the proposed technique is able to detect over 80% of the contact calls detected by a human operator and to produce about 26 false alarms per 24 h of observation. i n t r o d u c t i o n Continuous monitoring of North Atlantic right whales (NARW) presence in large areas can be accomplished by passive acoustical methods using data recordings obtained from distributed autonomous hydrophone systems To reduce subjectivity and to decrease the labor costs, various NARW detection methods known from the literature can be used (see e.g., The goal of the research presented in this paper is to reduce the probability of false alarm in spectrogram-based detectors without negatively affecting the detection probability. The proposed technique is reduced to a multiple-stage hypotheses-testing process. In the initial stage, the spectrogram-based detector [11] is applied. The data segments accepted as signals in the initial stage are recognized using the proposed recognition technique. The hypothesis that the detected segment belongs to the known types of impulsive noise is tested in the second stage. If this hypothesis is rejected, a feature vector (FV) is extracted and tested in the final stage. Test results obtained using real data recordings are presented. d a t a m o d e l a n d p r o b l e m f o r m u l a t i o n We use the data model similar to that considered in We assume that the spectrogram-based detector is applied to the input data in the initial stage. For each 1 s data segmen

Genetic mapping and developmental timing of transmission ratio distortion in a mouse interspecific backcross

<p>Abstract</p> <p>Background</p> <p>Transmission ratio distortion (TRD), defined as statistically significant deviation from expected 1:1 Mendelian ratios of allele inheritance, results in a reduction of the expected progeny of a given genotype. Since TRD is a common occurrence within interspecific crosses, a mouse interspecific backcross was used to genetically map regions showing TRD, and a developmental analysis was performed to identify the timing of allele loss.</p> <p>Results</p> <p>Three independent events of statistically significant deviation from the expected 50:50 Mendelian inheritance ratios were observed in an interspecific backcross between the <it>Mus musculus </it>A/J and the <it>Mus spretus </it>SPRET/EiJ inbred strains. At weaning <it>M. musculus </it>alleles are preferentially inherited on Chromosome (Chr) 7, while <it>M. spretus </it>alleles are preferentially inherited on Chrs 10 and 11. Furthermore, alleles on Chr 3 modify the TRD on Chr 11. All TRD loci detected at weaning were present in Mendelian ratios at mid-gestation and at birth.</p> <p>Conclusions</p> <p>Given that Mendelian ratios of inheritance are observed for Chr 7, 10 and 11 during development and at birth, the underlying causes for the interspecific TRD events are the differential post-natal survival of pups with specific genotypes. These results are consistent with the TRD mechanism being deviation from Mendelian inheritance rather than meiotic drive or segregation distortion.</p