Regulation of a-Synuclein Membrane Binding and Its Implications

peer reviewe

Closure of population biobanks and direct-to-consumer genetic testing companies

Genetic research gained new momentum with the completion of the Human Genome Project in 2003. Formerly centered on the investigation of single-gene disorders, genetic research is increasingly targeting common complex diseases and in doing so is studying the whole genome, the environment and its impact on genomic variation. Consequently, biobanking initiatives have emerged around the world as a tool to sustain such progress. Whether they are small scale or longitudinal, public or private, commercial or non-commercial, biobanks should consider the possibility of closure. Interestingly, while raising important ethical issues, this topic has hardly been explored in the literature. Indeed, ethical issues associated with sale, insolvency, end of funding, or transfer of materials to other entities (which are all issues either related to or possible consequences of closure) are seldom the subject of discussion. In an attempt to fill this gap, this paper will discuss-using population and direct-to-consumer (DTC) genetic testing companies' biobanks as case studies-(1) international and national normative documents addressing the issue of closure and (2) the internal policies of population biobanks and DTC genetic testing companies. The analysis will inform the debate on biobank closure and elucidate the underlying ethical issues, which include, but are not limited to informed consent, storage and privacy

The calibration of the Sudbury Neutrino Observatory using uniformly distributed radioactive sources

The production and analysis of distributed sources of 24Na and 222Rn in the Sudbury Neutrino Observatory (SNO) are described. These unique sources provided accurate calibrations of the response to neutrons, produced through photodisintegration of the deuterons in the heavy water target, and to low energy betas and gammas. The application of these sources in determining the neutron detection efficiency and response of the 3He proportional counter array, and the characteristics of background Cherenkov light from trace amounts of natural radioactivity is described.Comment: 24 pages, 13 figure

3D Coronal Density Reconstruction and Retrieving the Magnetic Field Structure during Solar Minimum

Measurement of the coronal magnetic field is a crucial ingredient in understanding the nature of solar coronal phenomena at all scales. We employed STEREO/COR1 data obtained during a deep minimum of solar activity in February 2008 (Carrington rotation CR 2066) to retrieve and analyze the three-dimensional (3D) coronal electron density in the range of heights from 1.5 to 4 Rsun using a tomography method. With this, we qualitatively deduced structures of the coronal magnetic field. The 3D electron density analysis is complemented by the 3D STEREO/EUVI emissivity in the 195 A band obtained by tomography for the same CR. A global 3D MHD model of the solar corona was used to relate the reconstructed 3D density and emissivity to open/closed magnetic field structures. We show that the density maximum locations can serve as an indicator of current sheet position, while the locations of the density gradient maximum can be a reliable indicator of coronal hole boundaries. We find that the magnetic field configuration during CR 2066 has a tendency to become radially open at heliocentric distances greater than 2.5 Rsun. We also find that the potential field model with a fixed source surface (PFSS) is inconsistent with the boundaries between the regions with open and closed magnetic field structures. This indicates that the assumption of the potential nature of the coronal global magnetic field is not satisfied even during the deep solar minimum. Results of our 3D density reconstruction will help to constrain solar coronal field models and test the accuracy of the magnetic field approximations for coronal modeling.Comment: Published in "Solar Physics

Small-scale solar magnetic fields

As we resolve ever smaller structures in the solar atmosphere, it has become clear that magnetism is an important component of those small structures. Small-scale magnetism holds the key to many poorly understood facets of solar magnetism on all scales, such as the existence of a local dynamo, chromospheric heating, and flux emergence, to name a few. Here, we review our knowledge of small-scale photospheric fields, with particular emphasis on quiet-sun field, and discuss the implications of several results obtained recently using new instruments, as well as future prospects in this field of research.Comment: 43 pages, 18 figure

Reconciling Neutralino Relic Density with Yukawa Unified Supersymmetric Models

Supersymmetric grand unified models based on the gauge group SO(10) are especially attractive in light of recent data on neutrino masses. The simplest SO(10) SUSY GUT models predict unification of third generation Yukawa couplings in addition to the usual gauge coupling unification. Recent surveys of Yukawa unified SUSY GUT models predict an inverted scalar mass hierarchy in the spectrum of sparticle masses if the superpotential mu term is positive. In general, such models tend to predict an overabundance of dark matter in the universe. We survey several solutions to the dark matter problem in Yukawa unified supersymmetric models. One solution-- lowering the GUT scale mass value of first and second generation scalars-- leads to u_R and c_R squark masses in the 90-120 GeV regime, which should be accessible to Fermilab Tevatron experiments. We also examine relaxing gaugino mass universality which may solve the relic density problem by having neutralino annihilations via the Z or h resonances, or by having a wino-like LSP.Comment: 21 page file plus 9 figures; updated version to coincide with published versio

GenTAC registry report: Gender differences among individuals with genetically triggered thoracic aortic aneurysm and dissection

Previous data suggest women are at increased risk of death from aortic dissection. Therefore, we analyzed data from the GenTAC registry, the NIH‐sponsored program that collects information about individuals with genetically triggered thoracic aortic aneurysms and cardiovascular conditions. We performed cross‐sectional analyses in adults with Marfan syndrome (MFS), familial thoracic aortic aneurysm or dissection (FTAAD), bicuspid aortic valve (BAV) with thoracic aortic aneurysm or dissection, and subjects under 50 years of age with thoracic aortic aneurysm or dissection (TAAD <50 years). Women comprised 32% of 1,449 subjects and were 21% of subjects with BAV, 34% with FTAAD, 22% with TAAD <50 years, and 47% with MFS. Thoracic aortic dissections occurred with equal gender frequency yet women with BAV had more extensive dissections. Aortic size was smaller in women but was similar after controlling for BSA. Age at operation for aortic valve dysfunction, aneurysm or dissection did not differ by gender. Multivariate analysis (adjusting for age, BSA, hypertension, study site, diabetes, and subgroup diagnoses) showed that women had fewer total aortic surgeries (OR = 0.65, P  < 0.01) and were less likely to receive angiotensin converting enzyme inhibitors (ACEi; OR = 0.68, P  < 0.05). As in BAV, other genetically triggered aortic diseases such as FTAAD and TAAD <50 are more common in males. In women, decreased prevalence of aortic operations and less treatment with ACEi may be due to their smaller absolute aortic diameters. Longitudinal studies are needed to determine if women are at higher risk for adverse events. © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97193/1/35836_ftp.pd

The Yamato-type (CY) carbonaceous chondrite group: Analogues for the surface of asteroid Ryugu?

We report new mineralogical, petrographic and noble gas analyses of the carbonaceous chondrite meteorites Y-82162 (C1/2ung), Y-980115 (CI1), Y-86029 (CI1), Y-86720 (C2ung), Y-86789 (C2ung), and B-7904 (C2ung). Combining our results with literature data we show that these meteorites experienced varying degrees of aqueous alteration followed by short-lived thermal metamorphism at temperatures of >500 °C. These meteorites have similar mineralogy, textures and chemical characteristics suggesting that they are genetically related, and we strongly support the conclusion of Ikeda (1992) that they form a distinct group, the CYs (“Yamato-type”). The CY chondrites have the heaviest oxygen isotopic compositions (δ17O ˜12‰, δ18O ˜22‰) of any meteorite group, high abundances of Fe-sulphides (˜10 ‒ 30 vol%) and phosphates, and contain large grains of periclase and unusual objects of secondary minerals not reported in other carbonaceous chondrites. These features cannot be attributed to parent body processes alone, and indicate that the CYs had a different starting mineralogy and/or alteration history to other chondrite groups, perhaps because they formed in a different region of the protoplanetary disk. The short cosmic-ray exposure ages (≤1.3 Ma) of the CY chondrites suggest that they are derived from a near-Earth source, with recent observations by the Hayabusa2 spacecraft highlighting a possible link to the rubble-pile asteroid Ryugu

Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review