Bioaccumulation of PCB & DDE methyl sulfones in marine mammals and their interactions with receptor proteins

PCB and DDE-Methyl sulphone metabolites are the product of enzymatic and bile acid entero hepatic metabolism in the final phase (III) of PCB and DDE detoxification in mammals following hepatic microsomal cytochrome P450-dependent metabolism (phase I) and conjugation (phase II). There is good evidence that PCB and DDE methyl sulphone (MSF) metabolites interfere with steroid binding to a receptor protein in uterine epithelium (uteroglobin - UG2 and bronchial epithelium (clara cell secretory protein - CCSP). UG and CCSP are homologous 16,000 Da proteins with different tissue-specific functions. UG binds progesterone in the pre-implantation uterus to signal localised endometrial thickening and capillary formation, vital for successful attachment of the fertilised embryo. PCB-MSFs can displace progesterone in the mammalian uterus due to their higher affinity for UG, resulting in implantation failure or early fetal death. CCSP however, functions to sequester phospholipase A2 (PLA2) released in response to stress (pathogenic infection / injury) to suppress inflammatory responses triggered by PLA2 in bronchial epithelium. CCSP is also known as retinol-binding protein (RBP) transporting retinol (vit A) to target epithelia for a functional immune response*. Studies with Harbour Seals demonstrated displacement of retinol from RBP by hydroxy-PCB metabolites resulting in immunosuppression. PCB-MSFs have been shown to accumulate in clara cells and uterine epithelium in laboratory radioactive tracer studies and CCSP-knock out studies with mice. PCB and DDE -MSFs burdens have been found in marine mammals, suggesting they may be subject to reproductive and immuno-toxic effects of these metabolites. This study determines PCB and DDE-MSFs burdens in tissues (including lung & uterus) of Harbour Seal (Phoca vitulina) and Striped Dolphin (Stenella coeruleoalba) morbillivirus victims and characterises the marine mammalian UG/CCSP protein

Possible X-ray diagnostic for jet/disk dominance in Type 1 AGN

Using Rossi X-ray Timing Explorer Seyfert 1 and 1.2 data spanning 9 years, we study correlations between X-ray spectral features. The sample consists of 350 time-resolved spectra from 12 Seyfert 1 and 1.2 galaxies. Each spectrum is fitted to a model with an intrinsic powerlaw X-ray spectrum produced close to the central black hole that is reprocessed and absorbed by material around the black hole. To test the robustness of our results, we performed Monte Carlo simulations of the spectral sample. We find a complex relationship between the iron line equivalent width (EW) and the underlying power law index (Gamma). The data reveal a correlation between Gamma and EW which turns over at Gamma <~ 2, but finds a weak anti-correlation for steeper photon indices. We propose that this relationship is driven by dilution of a disk spectrum (which includes the narrow iron line) by a beamed jet component and, hence, could be used as a diagnostic of jet-dominance. In addition, our sample shows a strong correlation between the reflection fraction (R) and Gamma, but we find that it is likely the result of modeling degeneracies. We also see the X-ray Baldwin effect (an anti-correlation between the 2-10 keV X-ray luminosity and EW) for the sample as a whole, but not for the individual galaxies and galaxy types.Comment: Accepted for publication in ApJ, 14 page

Significance of low energy impact damage on modal parameters of composite beams by design of experiments

This paper presents an experimental study on the effects of multi-site damage on the vibration response of composite beams damaged by low energy impacts around the barely visible impact damage limit (BVID). The variation of the modal parameters with different levels of impact energy and density of damage is studied. Vibration tests have been carried out with both burst random and classical sine dwell excitations in order to compare that which of the methods among Polymax and Half Bandwidth Method is more suitable for damping estimation in the presence of damage. Design of experiments (DOE) performed on the experimental data show that natural frequency is a more sensitive parameter for damage detection than the damping ratio. It also highlighted energy of impact as the factor having a more significant effect on the modal parameters. Half Bandwidth Method is found to be unsuitable for damping estimation in the presence of damage

Comparison of cattail (Typha sp.) occurrence on a photo-interpreted map versus a satellite data map

A comparison between a 1985 photo-interpreted vegetation map and a vegetation map made from classified 1987 satellite data of the Loxahatchee National Wildlife Refuge showed that 81% of samples taken in areas occupied by cattail (Typha sp.) on the photo-interpreted map corresponded with cattail on the satellite data map.(5 page document

Doubly heavy quark baryon spectroscopy and semileptonic decay

Working in the framework of a nonrelativistic quark model we evaluate the spectra and semileptonic decay widths for the ground state of doubly heavy $\Xi$ and $\Omega$ baryons. We solve the three-body problem using a variational ansatz made possible by the constraints imposed by heavy quark spin symmetry. In order to check the dependence of our resultson the inter-quark interaction we have used five different quarkquark potentials which include Coulomb and hyperfine terms coming fromone-gluon exchange, plus a confining term. Our results for the spectra are in good agreement with a previous calculation done using a Faddeev approach. For the semileptonic decay our results for the total decay widths are in a good agreement with the ones obtained within a relativistic quark model in the quark-diquark approximation.Comment: Talk given at the IVth International Conference on Quarks an Nuclear Physics (QNP06), Madrid, June 5th-10th 200

Shadowing Ministers: Monitoring Partners in Coalition Governments

In this article the authors study delegation problems within multiparty coalition governments. They argue that coalition parties can use the committee system to “shadow” the ministers of their partners; that is, they can appoint committee chairs from other governing parties, who will then be well placed to monitor and/or check the actions of the corresponding ministers. The authors analyze which ministers should be shadowed if governing parties seek to minimize the aggregate policy losses they suffer as the result of ministers pursuing their own parties’ interests rather than the coalition’s. Based on data from 19 mostly European parliamentary democracies, the authors find that the greater the policy disagreement between a minister’s party and its partners, the more likely the minister is to be shadowed

Management of information technology in Swedish firms: An empirical study

This study examines the role and the involvement of management in information technology acquisition, planning, and development. The results indicate that top management plays a major role in setting the overall information technology policies. In addition, the Chief Information Officer (CIO) plays a crucial role in the merger of information strategy and corporate strategy. The result also indicates that user\u27s satisfaction is considered to be the most important r factor for justification of information technology acquisition