Low-frequency QPO from the 11 Hz accreting pulsar in Terzan 5: not frame dragging

We report on 6 RXTE observations taken during the 2010 outburst of the 11 Hz accreting pulsar IGR J17480-2446 located in the globular cluster Terzan 5. During these observations we find power spectra which resemble those seen in Z-type high-luminosity neutron star low-mass X-ray binaries, with a quasi-periodic oscillation (QPO) in the 35-50 Hz range simultaneous with a kHz QPO and broad band noise. Using well known frequency-frequency correlations, we identify the 35-50 Hz QPOs as the horizontal branch oscillations (HBO), which were previously suggested to be due to Lense-Thirring precession. As IGR J17480-2446 spins more than an order of magnitude more slowly than any of the other neutron stars where these QPOs were found, this QPO can not be explained by frame dragging. By extension, this casts doubt on the Lense-Thirring precession model for other low-frequency QPOs in neutron-star and perhaps even black-hole systems.Comment: 6 pages, 5 figures, Accepted for publication in ApJ

The adaptive problem of absent third-party punishment

Language is a uniquely human behaviour, which has presented unique adaptive problems. Prominent among these is the transmission of information that may affect an individual’s reputation. The possibility of punishment of those with a low reputation by absent third parties has created a selective pressure on human beings that is not shared by any other species. This has led to the evolution of unique cognitive structures that are capable of handling such a novel adaptive challenge. One of these, we argue, is the propositional theory of mind, which enables individuals to model, and potentially manipulate, their own reputation in the minds of other group members, by representing the beliefs that others have about the first party’s intentions and actions. Support for our theoretical model is provided by an observational study on tattling in two preschools, and an experimental study of giving under threat of gossip in a dictator game

Joining up health and bioinformatics: e-science meets e-health

CLEF (Co-operative Clinical e-Science Framework) is an MRC sponsored project in the e-Science programme that aims to establish methodologies and a technical infrastructure forthe next generation of integrated clinical and bioscience research. It is developing methodsfor managing and using pseudonymised repositories of the long-term patient histories whichcan be linked to genetic, genomic information or used to support patient care. CLEF concentrateson removing key barriers to managing such repositories ? ethical issues, informationcapture, integration of disparate sources into coherent ?chronicles? of events, userorientedmechanisms for querying and displaying the information, and compiling the requiredknowledge resources. This paper describes the overall information flow and technicalapproach designed to meet these aims within a Grid framework

What Counts in Brain Aging? Design-Based Stereological Analysis of Cell Number

The advent and implementation of new design-based stereological techniques allows the quantification of cell number without the assumptions required when obtaining areal densities. These new techniques are rapidly becoming the standard for quantifying cell number, particularly in aging studies. Recently, studies using stereological techniques have failed to confirm earlier findings regarding age-associated neural loss. This newly emerging view of retained cell number during aging is having a major impact on biogerontology, prompting revaluation of long-standing hypotheses of age-related cell loss as causal for age-related impairments in brain functioning. Rather than focus on neuronal loss as the end-result of a negative cascade of neuronal injury, research has begun to consider that age-related behavioral declines may reflect neuronal dysfunction (e.g., synaptic or receptor loss, signal transduction deficits) instead of neuronal death. Here we discuss design-based stereology in the context of age-related change in brain cell number and its impact on consideration of structural change in brain aging. Emergence of this method of morphometries, however, can have relevance to many areas of gerontological researc

A Role for the Vacuolating Cytotoxin, VacA, in Colonization and Helicobacter pylori-Induced Metaplasia in the Stomach

Carriage of Helicobacter pylori strains producing more active (s1/i1) forms of VacA is strongly associated with gas-tric adenocarcinoma. To our knowledge, we are the first to determine effects of different polymorphic forms of VacA on inflammation and metaplasia in the mouse stomach. Bacteria producing the less active s2/i2 form of VacA colonized mice more efficiently than mutants null for VacA or producing more active forms of it, providing the first evidence of a positive role for the minimally active s2/i2 toxin. Strains producing more active toxin forms induced more severe and extensive metaplasia and in flammation in the mouse stomach than strains producing weakly active (s2/i2) toxin. We also examined the association in humans, controlling for cag PAI status. In human gastric biopsy specimens, the vacA i1 allele was strongly associated with precancerous intestinal metaplasia, with almost complete absence of intestinal metaplasia in subjects infected with i2-type strains, even in a vacA s1, cagA+ background

Predicting Graph Categories from Structural Properties

Complex networks are often categorized according to the underlying phenomena that they represent such as molecular interactions, re-tweets, and brain activity. In this work, we investigate the problem of predicting the category (domain) of arbitrary networks. This includes complex networks from different domains as well as synthetically generated graphs from five different network models. A classification accuracy of 96.6% is achieved using a random forest classifier with both real and synthetic networks. This work makes two important findings. First, our results indicate that complex networks from various domains have distinct structural properties that allow us to predict with high accuracy the category of a new previously unseen network. Second, synthetic graphs are trivial to classify as the classification model can predict with near-certainty the network model used to generate it. Overall, the results demonstrate that networks drawn from different domains (and network models) are trivial to distinguish using only a handful of simple structural properties

Positronics of radiation-induced effects in chalcogenide glassy semiconductors

Using As2S3 and AsS2 glasses as an example, the principal possibility of using positron annihilation spectroscopy methods for studying the evolution of the free volume of hollow nanoobjects in chalcogenide glassy semiconductors exposed to radiation is shown. The results obtained by measurements of the positron annihilation lifetime and Doppler broadening of the annihilation line in reverse chronological order are in full agreement with the optical spectroscopy data in the region of the fundamental absorption edge, being adequately described within coordination defect-formation and physical-aging models