Probing the Nature of Short Swift Bursts via Deep INTEGRAL Monitoring of GRB 050925

We present results from Swift, XMM-Newton, and deep INTEGRAL monitoring in the region of GRB 050925. This short Swift burst is a candidate for a newly discovered soft gamma-ray repeater (SGR) with the following observational burst properties: 1) galactic plane (b=-0.1 deg) localization, 2) 150 msec duration, and 3) a blackbody rather than a simple power-law spectral shape (with a significance level of 97%). We found two possible X-ray counterparts of GRB 050925 by comparing the X-ray images from Swift XRT and XMM-Newton. Both X-ray sources show the transient behavior with a power-law decay index shallower than -1. We found no hard X-ray emission nor any additional burst from the location of GRB 050925 in ~5 Ms of INTEGRAL data. We discuss about the three BATSE short bursts which might be associated with GRB 050925, based on their location and the duration. Assuming GRB 050925 is associated with the H II regions (W 58) at the galactic longitude of l=70 deg, we also discuss the source frame properties of GRB 050925.Comment: 13 pages, 13 figures, accepted for publication in ASR special issue on Neutron Stars and Gamma Ray Bursts, full resolution of Fig 5 is available at http://asd.gsfc.nasa.gov/Takanori.Sakamoto/GRB050925/integral_ibis_images.ep

Exact Solution for the Critical State in Thin Superconductor Strips with Field Dependent or Anisotropic Pinning

An exact analytical solution is given for the critical state problem in long thin superconductor strips in a perpendicular magnetic field, when the critical current density j_c(B) depends on the local induction B according to a simple three-parameter model. This model describes both isotropic superconductors with this j_c(B) dependence, but also superconductors with anisotropic pinning described by a dependence j_c(theta) where theta is the tilt angle of the flux lines away from the normal to the specimen plane

Omineca Herald, October, 04, 1979

The relation between progression of cerebral small vessel disease (SVD) and gait decline is uncertain, and diffusion tensor imaging (DTI) studies on gait decline are lacking. We therefore investigated the longitudinal associations between (micro) structural brain changes and gait decline in SVD using DTI. 275 participants were included from the Radboud University Nijmegen Diffusion tensor and Magnetic resonance imaging Cohort (RUN DMC), a prospective cohort of participants with cerebral small vessel disease aged 50–85years. Gait (using GAITRite) and magnetic resonance imaging measures were assessed during baseline (2006–2007) and follow-up (2011−2012). Linear regression analysis was used to investigate the association between changes in conventional magnetic resonance and diffusion tensor imaging measures and gait decline. Tract-based spatial statistics analysis was used to investigate region-specific associations between changes in white matter integrity and gait decline. 56.2% were male, mean age was 62.9years (SD8.2), mean follow-up duration was 5.4years (SD0.2) and mean gait speed decline was 0.2m/s (SD0.2). Stride length decline was associated with white matter atrophy (β=0.16, p=0.007), and increase in mean white matter radial diffusivity and mean diffusivity, and decrease in mean fractional anisotropy (respectively, β=−0.14, p=0.009; β=−0.12, p=0.018; β=0.10, p=0.049), independent of age, sex, height, follow-up duration and baseline stride length. Tract-based spatial statistics analysis showed significant associations between stride length decline and fractional anisotropy decrease and mean diffusivity increase (primarily explained by radial diffusivity increase) in multiple white matter tracts, with the strongest associations found in the corpus callosum and corona radiata, independent of traditional small vessel disease markers. White matter atrophy and loss of white matter integrity are associated with gait decline in older adults with small vessel disease after 5years of follow-up. These findings suggest that progression of SVD might play an important role in gait decline. Keywords: Cerebral small vessel disease (SVD), MRI, Diffusion tensor imaging (DTI), Tract-based spatial statistics (TBSS), Gai

Cohort study ON Neuroimaging, Etiology and Cognitive consequences of Transient neurological attacks (CONNECT): Study rationale and protocol

Background: Transient ischemic attacks (TIA) are characterized by acute onset focal neurological symptoms and complete recovery within 24hours. Attacks of nonfocal symptoms not fulfilling the criteria for TIA but lacking a clear alternative diagnosis are called transient neurological attacks (TNA). Although TIA symptoms are transient in nature, cognitive complaints may persist. In particular, attacks consisting of both focal and nonfocal symptoms (mixed TNA) have been found to be associated with an increased risk of dementia. We aim to study the prevalence, etiology and risk factors of cognitive impairment after TIA or TNA. Methods/Design: CONNECT is a prospective cohort study on cognitive function after TIA and TNA. In total, 150 patients aged ≤45years with a recent (<7days after onset) TIA or TNA and no history of stroke or dementia will be included. We will classify events as: TIA, nonfocal TNA, or mixed TNA. Known short lasting paroxysmal neurological disorders like migraine aura, seizures and Ménière disease are excluded from the diagnosis of TNA. Patients will complete a comprehensive neuropsychological assessment and undergo MRI <7days after the qualifying event and again after six months. The primary clinical outcomes will be cognitive function at baseline and six months after the primary event. Imaging outcomes include the prevalence and evolution of DWI lesions, white matter hyperintensities and lacunes, as well as resting state networks functionality and white matter microstructural integrity. Differences between types of event and DWI, as well as determinants of both clinical and imaging outcomes, will be assessed. Discussion: CONNECT can provide insight in the prevalence, etiology and risk factors of cognitive impairment after TIA and TNA and thereby potentially identify a new group of patients at increased risk of cognitive impairment

Programmable models of growth and mutation of cancer-cell populations

In this paper we propose a systematic approach to construct mathematical models describing populations of cancer-cells at different stages of disease development. The methodology we propose is based on stochastic Concurrent Constraint Programming, a flexible stochastic modelling language. The methodology is tested on (and partially motivated by) the study of prostate cancer. In particular, we prove how our method is suitable to systematically reconstruct different mathematical models of prostate cancer growth - together with interactions with different kinds of hormone therapy - at different levels of refinement.Comment: In Proceedings CompMod 2011, arXiv:1109.104

Discovery of Rubidium, Strontium, Molybdenum, and Rhodium Isotopes

Currently, thirty-one rubidium, thirty-five strontium, thirty-five molybdenum and thirty-eight rhodium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.Comment: To be published in Atomic Data and Nuclear Data Table

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Expedition 361 summary

International Ocean Discovery Program Expedition 361 drilled six sites on the southeast African margin (southwest Indian Ocean) and in the Indian-Atlantic Ocean gateway, from 30 January to 31 March 2016. In total, 5175 m of core was recovered, with an average recovery of 102%, during 29.7 days of on-site operations. The sites, situated in the Mozambique Channel at locations directly influenced by discharge from the Zambezi and Limpopo River catchments, the Natal Valley, the Agulhas Plateau, and Cape Basin, were targeted to reconstruct the history of the greater Agulhas Current system over the past ~5 My. The Agulhas Current is the strongest western boundary current in the Southern Hemisphere, transporting some 70 Sv of warm, saline surface water from the tropical Indian Ocean along the East African margin to the tip of Africa. Exchanges of heat and moisture with the atmosphere influence southern African climates, including individual weather systems such as extratropical cyclone formation in the region and rainfall patterns. Recent ocean model and paleoceanographic data further point at a potential role of the Agulhas Current in controlling the strength and mode of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Pleistocene. Spillage of saline Agulhas water into the South Atlantic stimulates buoyancy anomalies that may influence basin-wide AMOC, with implications for convective activity in the North Atlantic and global climate change. The main objectives of the expedition were to establish the role of the Agulhas Current in climatic changes during the Pliocene–Pleistocene, specifically to document the dynamics of the Indian-Atlantic Ocean gateway circulation during this time, to examine the connection of the Agulhas leakage and AMOC, and to address the influence of the Agulhas Current on African terrestrial climates and coincidences with human evolution. Additionally, the expedition set out to fulfill the needs of Ancillary Project Letter number 845, consisting of high-resolution interstitial water sampling to help constrain the temperature and salinity profiles of the ocean during the Last Glacial Maximum. The expedition made major strides toward fulfilling each of these objectives. The recovered sequences allowed generation of complete spliced stratigraphic sections that range from 0 to between ~0.13 and 7 Ma. This sediment will provide decadal- to millennial-scale climatic records that will allow answering the paleoceanographic and paleoclimatic questions set out in the drilling proposal