Towards Gravitational Wave Signals from Realistic Core Collapse Supernova Models

We have computed the gravitational wave signal from supernova core collapse using the presently most realistic input physics available. We start from state-of-the-art progenitor models of rotating and non-rotating massive stars, and simulate the dynamics of their core collapse by integrating the equations of axisymmetric hydrodynamics together with the Boltzmann equation for the neutrino transport including an elaborate description of neutrino interactions, and a realistic equation of state. We compute the quadrupole wave amplitudes, the Fourier wave spectra, the amount of energy radiated in form of gravitational waves, and the S/N ratios for the LIGO and the tuned Advanced LIGO interferometers resulting both from non-radial mass motion and anisotropic neutrino emission. The simulations demonstrate that the dominant contribution to the gravitational wave signal is produced by neutrino-driven convection behind the supernova shock. For stellar cores rotating at the extreme of current stellar evolution predictions, the core-bounce signal is detectable with advanced LIGO up to a distance of 5kpc, whereas the signal from post-shock convection is observable up to a distance of about 100kpc. If the core is non-rotating its gravitational wave emission can be measured up to a distance of 15kpc, while the signal from the Ledoux convection in the deleptonizing, nascent neutron star can be detected up to a distance of 10kpc. Both kinds of signals are generically produced by convection in any core collapse supernova.Comment: 9 pages, 13 figures, Latex, submitted to ApJ, error in ps-file fixed; figures in full resolution are available upon reques

Investigação do haplótipo 5' da globina β em indígenas brasileiros

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The first determination of Generalized Polarizabilities of the proton by a Virtual Compton Scattering experiment

Absolute differential cross sections for the reaction (e+p -> e+p+gamma) have been measured at a four-momentum transfer with virtuality Q^2=0.33 GeV^2 and polarization \epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum of the outgoing photon in the photon-proton center of mass frame. The experiment has been performed with the high resolution spectrometers at the Mainz Microtron MAMI. From the photon angular distributions, two structure functions which are a linear combination of the generalized polarizabilities have been determined for the first time.Comment: 4 pages, 3 figure

Measurement of Rlt and Atl in the 4He(e,e'p)3H Reaction at pmiss of 130-300 MeV/c

We have measured the 4He(e,e'p)3H reaction at missing momenta of 130-300 MeV/c using the three-spectrometer facility at the Mainz microtron MAMI. Data were taken in perpendicular kinematics to allow us to determine the response function Rlt and the asymmetry term Atl. The data are compared to both relativistic and non-relativistic calculations.Comment: To be published in the European Physical Journal

Evolutionary concepts in predicting and evaluating the impact of mass chemotherapy schistosomiasis control programmes on parasites and their hosts

Schistosomiasis is a parasitic disease of significant medical and veterinary importance in many regions of the world. Recent shifts in global health policy have led towards the implementation of mass chemotherapeutic control programmes at the national scale in previously ‘neglected’ countries such as those within sub-Saharan Africa. Evolutionary theory has an important role to play in the design, application and interpretation of such programmes. Whilst celebrating the rapid success achieved to date by such programmes, in terms of reduced infection prevalence, intensity and associated human morbidity, evolutionary change in response to drug selection pressure may be predicted under certain circumstances, particularly in terms of the development of potential drug resistance, evolutionary changes in parasite virulence, transmission and host use, and/or competitive interactions with co-infecting pathogens. Theoretical and empirical data gained to date serve to highlight the importance of careful monitoring and evaluation of parasites and their hosts whenever and wherever chemotherapy is applied and where parasite transmission remains

Can a systems approach produce a better understanding of mood disorders?

Background: One in twenty-five people suffer from a mood disorder. Current treatments are sub-optimal with poor patient response and uncertain modes-of-action. There is thus a need to better understand underlying mechanisms that determine mood, and how these go wrong in affective disorders. Systems biology approaches have yielded important biological discoveries for other complex diseases such as cancer, and their potential in affective disorders will be reviewed. Scope of review: This review will provide a general background to affective disorders, plus an outline of experimental and computational systems biology. The current application of these approaches in understanding affective disorders will be considered, and future recommendations made. Major conclusions: Experimental systems biology has been applied to the study of affective disorders, especially at the genome and transcriptomic levels. However, data generation has been slowed by a lack of human tissue or suitable animal models. At present, computational systems biology has only be applied to understanding affective disorders on a few occasions. These studies provide sufficient novel biological insight to motivate further use of computational biology in this field. General significance: In common with many complex diseases much time and money has been spent on the generation of large-scale experimental datasets. The next step is to use the emerging computational approaches, predominantly developed in the field of oncology, to leverage the most biological insight from these datasets. This will lead to the critical breakthroughs required for more effective diagnosis, stratification and treatment of affective disorders

The Evolutionary Dynamics of a Rapidly Mutating Virus within and between Hosts: The Case of Hepatitis C Virus

Many pathogens associated with chronic infections evolve so rapidly that strains found late in an infection have little in common with the initial strain. This raises questions at different levels of analysis because rapid within-host evolution affects the course of an infection, but it can also affect the possibility for natural selection to act at the between-host level. We present a nested approach that incorporates within-host evolutionary dynamics of a rapidly mutating virus (hepatitis C virus) targeted by a cellular cross-reactive immune response, into an epidemiological perspective. The viral trait we follow is the replication rate of the strain initiating the infection. We find that, even for rapidly evolving viruses, the replication rate of the initial strain has a strong effect on the fitness of an infection. Moreover, infections caused by slowly replicating viruses have the highest infection fitness (i.e., lead to more secondary infections), but strains with higher replication rates tend to dominate within a host in the long-term. We also study the effect of cross-reactive immunity and viral mutation rate on infection life history traits. For instance, because of the stochastic nature of our approach, we can identify factors affecting the outcome of the infection (acute or chronic infections). Finally, we show that anti-viral treatments modify the value of the optimal initial replication rate and that the timing of the treatment administration can have public health consequences due to within-host evolution. Our results support the idea that natural selection can act on the replication rate of rapidly evolving viruses at the between-host level. It also provides a mechanistic description of within-host constraints, such as cross-reactive immunity, and shows how these constraints affect the infection fitness. This model raises questions that can be tested experimentally and underlines the necessity to consider the evolution of quantitative traits to understand the outcome and the fitness of an infection

State of the art of immunoassay methods for B-type natriuretic peptides: An update

The aim of this review article is to give an update on the state of the art of the immunoassay methods for the measurement of B-type natriuretic peptide (BNP) and its related peptides. Using chromatographic procedures, several studies reported an increasing number of circulating peptides related to BNP in human plasma of patients with heart failure. These peptides may have reduced or even no biological activity. Furthermore, other studies have suggested that, using immunoassays that are considered specific for BNP, the precursor of the peptide hormone, proBNP, constitutes a major portion of the peptide measured in plasma of patients with heart failure. Because BNP immunoassay methods show large (up to 50%) systematic differences in values, the use of identical decision values for all immunoassay methods, as suggested by the most recent international guidelines, seems unreasonable. Since proBNP significantly cross-reacts with all commercial immunoassay methods considered specific for BNP, manufacturers should test and clearly declare the degree of cross-reactivity of glycosylated and non-glycosylated proBNP in their BNP immunoassay methods. Clinicians should take into account that there are large systematic differences between methods when they compare results from different laboratories that use different BNP immunoassays. On the other hand, clinical laboratories should take part in external quality assessment (EQA) programs to evaluate the bias of their method in comparison to other BNP methods. Finally, the authors believe that the development of more specific methods for the active peptide, BNP1–32, should reduce the systematic differences between methods and result in better harmonization of results

Epithelial-Mesenchymal Transition in Cancer: Parallels Between Normal Development and Tumor Progression

From the earliest stages of embryonic development, cells of epithelial and mesenchymal origin contribute to the structure and function of developing organs. However, these phenotypes are not always permanent, and instead, under the appropriate conditions, epithelial and mesenchymal cells convert between these two phenotypes. These processes, termed Epithelial-Mesenchymal Transition (EMT), or the reverse Mesenchymal-Epithelial Transition (MET), are required for complex body patterning and morphogenesis. In addition, epithelial plasticity and the acquisition of invasive properties without the full commitment to a mesenchymal phenotype are critical in development, particularly during branching morphogenesis in the mammary gland. Recent work in cancer has identified an analogous plasticity of cellular phenotypes whereby epithelial cancer cells acquire mesenchymal features that permit escape from the primary tumor. Because local invasion is thought to be a necessary first step in metastatic dissemination, EMT and epithelial plasticity are hypothesized to contribute to tumor progression. Similarities between developmental and oncogenic EMT have led to the identification of common contributing pathways, suggesting that the reactivation of developmental pathways in breast and other cancers contributes to tumor progression. For example, developmental EMT regulators including Snail/Slug, Twist, Six1, and Cripto, along with developmental signaling pathways including TGF-β and Wnt/β-catenin, are misexpressed in breast cancer and correlate with poor clinical outcomes. This review focuses on the parallels between epithelial plasticity/EMT in the mammary gland and other organs during development, and on a selection of developmental EMT regulators that are misexpressed specifically during breast cancer