Automated Classification of Sloan Digital Sky Survey (SDSS) Stellar Spectra using Artificial Neural Networks

Automated techniques have been developed to automate the process of classification of objects or their analysis. The large datasets provided by upcoming spectroscopic surveys with dedicated telescopes urges scientists to use these automated techniques for analysis of such large datasets which are now available to the community. Sloan Digital Sky Survey (SDSS) is one of such surveys releasing massive datasets. We use Probabilistic Neural Network (PNN) for automatic classification of about 5000 SDSS spectra into 158 spectral type of a reference library ranging from O type to M type stars.Comment: 27 pages, 11 figures To appear in Astrophys. Space Sci., 200

Distinct patterns of ΔFosB induction in brain by drugs of abuse

The transcription factor ΔFosB accumulates and persists in brain in response to chronic stimulation. This accumulation after chronic exposure to drugs of abuse has been demonstrated previously by Western blot most dramatically in striatal regions, including dorsal striatum (caudate/putamen) and nucleus accumbens. In the present study, we used immunohistochemistry to define with greater anatomical precision the induction of ΔFosB throughout the rodent brain after chronic drug treatment. We also extended previous research involving cocaine, morphine, and nicotine to two additional drugs of abuse, ethanol and Δ9-tetrahydrocannabinol (Δ9-THC, the active ingredient in marijuana). We show here that chronic, but not acute, administration of each of four drugs of abuse, cocaine, morphine, ethanol, and Δ9-THC, robustly induces ΔFosB in nucleus accumbens, although different patterns in the core vs. shell subregions of this nucleus were apparent for the different drugs. The drugs also differed in their degree of ΔFosB induction in dorsal striatum. In addition, all four drugs induced ΔFosB in prefrontal cortex, with the greatest effects observed with cocaine and ethanol, and all of the drugs induced ΔFosB to a small extent in amygdala. Furthermore, all drugs induced ΔFosB in the hippocampus, and, with the exception of ethanol, most of this induction was seen in the dentate. Lower levels of ΔFosB induction were seen in other brain areas in response to a particular drug treatment. These findings provide further evidence that induction of ΔFosB in nucleus accumbens is a common action of virtually all drugs of abuse and that, beyond nucleus accumbens, each drug induces ΔFosB in a region-specific manner in brain

State of the field: What can political ethnography tell us about anti-politics and democratic disaffection?

This article adopts and reinvents the ethnographic approach to uncover what governing elites do, and how they respond to public disaffection. Although there is significant work on the citizens’ attitudes to the governing elite (the demand side) there is little work on how elites interpret and respond to public disaffection (the supply side). We argue that ethnography is the best available research method for collecting data on the supply side. In doing so, we tackle long-standing stereotypes in political science about the ethnographic method and what it is good for. We highlight how the innovative and varied practices of contemporary ethnography are ideally suited to shedding light into the ‘black box’ of elite politics. We demonstrate the potential pay-off with reference to important examples of elite ethnography from the margins of political science scholarship. The implications from these rich studies, we argue, suggest a reorientation of how we understand the drivers of public disaffection and the role that political elites play in exacerbating cynicism and disappointment. We conclude by pointing to the benefits to the discipline in embracing elite ethnography both to diversify the methodological toolkit in explaining the complex dynamics of disaffection,and to better enable engagement in renewed public debate about the political establishment

Spallation reactions. A successful interplay between modeling and applications

The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie

Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

The $B^0$-$\bar B^0$ oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives $\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)}$ ps$^{-1}$.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

No, Prime Minister:Explaining the House of Commons’ Vote on Intervention in Syria

On 29 August 2013, the UK House of Commons inflicted the first defeat on a Prime Minister over a matter of war and peace since 1782. Recalled to debate and vote on UK intervention in Syria, the Commons humbled the government and crucially impacted the development of UK foreign policy. This article places that vote, and the developments leading to it, in the context of the role of parliaments in security policy and explores the relationships between parliamentary influence, leadership, intra-party and intra-coalition politics, and public opinion. From an in-depth analysis of leaders’ statements and parliamentary debate, we find a combination of intra-party politics and party leadership were most significant. An additional factor–the role of historical precedent–was also important. Our analysis explores the fluidity and interconnectedness of the various factors for parliamentary influence in foreign policy and offers directions for future theoretical development and empirical research.</p

Humoral Immune Response and Safety of SARS-CoV-2 Vaccination in Pediatric Inflammatory Bowel Disease

INTRODUCTION:Children with inflammatory bowel disease (IBD) may respond differently to COVID-19 immunization as compared with healthy children or adults with IBD. Those younger than 12 years receive a lower vaccine dose than adults. We sought to describe the safety and humoral immune response to COVID-19 vaccine in children with IBD.METHODS:We recruited children with IBD, ages 5-17 years, who received ≥ 2 doses of the BNT162b2 vaccine by a direct-to-patient outreach and at select sites. Patient demographics, IBD characteristics, medication use, and vaccine adverse events were collected. A subset of participants had quantitative measurement of anti-receptor binding domain IgG antibodies after 2-part immunization.RESULTS:Our study population included 280 participants. Only 1 participant required an ED visit or hospitalization because of an adverse event. Of 99 participants who underwent anti-receptor binding domain IgG antibody measurement, 98 had a detectable antibody, with a mean antibody level of 43.0 g/mL (SD 67) and a median of 22 g/mL (interquartile range 12-38). In adjusted analyses, older age (P = 0.028) and antitumor necrosis factor monotherapy compared with immunomodulators alone (P = 0.005) were associated with a decreased antibody level. Antibody response in patients treated with antitumor necrosis factor combination vs monotherapy was numerically lower but not significant.DISCUSSION:Humoral immune response to COVID-19 immunization in children with IBD was robust, despite a high proportion of this pediatric cohort being treated with immunosuppressive agents. Severe vaccine-related AEs were rare. Overall, these findings provide a high level of reassurance that pediatric patients with IBD respond well and safely to SARS-CoV-2 vaccination

The Dynamics of Brane-World Cosmological Models

Brane-world cosmology is motivated by recent developments in string/M-theory and offers a new perspective on the hierarchy problem. In the brane-world scenario, our Universe is a four-dimensional subspace or {\em brane} embedded in a higher-dimensional {\em bulk} spacetime. Ordinary matter fields are confined to the brane while the gravitational field can also propagate in the bulk, leading to modifications of Einstein's theory of general relativity at high energies. In particular, the Randall-Sundrum-type models are self-consistent and simple and allow for an investigation of the essential non-linear gravitational dynamics. The governing field equations induced on the brane differ from the general relativistic equations in that there are nonlocal effects from the free gravitational field in the bulk, transmitted via the projection of the bulk Weyl tensor, and the local quadratic energy-momentum corrections, which are significant in the high-energy regime close to the initial singularity. In this review we discuss the asymptotic dynamical evolution of spatially homogeneous brane-world cosmological models containing both a perfect fluid and a scalar field close to the initial singularity. Using dynamical systems techniques it is found that, for models with a physically relevant equation of state, an isotropic singularity is a past-attractor in all orthogonal spatially homogeneous models (including Bianchi type IX models). In addition, we describe the dynamics in a class of inhomogeneous brane-world models, and show that these models also have an isotropic initial singularity. These results provide support for the conjecture that typically the initial cosmological singularity is isotropic in brane-world cosmology.Comment: Einstein Centennial Review Article: to appear in CJ