Absolute Magnitude Distribution And Light Curves Of Gamma-Ray Burst Supernovae

Photometry data were collected from the literature and analyzed for supernovae that are thought to have a gamma-ray burst association. There are several gamma-ray burst afterglow light curves that appear to have a supernova component. For these light curves, the supernova component was extracted and analyzed. A supernova light curve model was used to help determine the peak absolute magnitudes as well as estimates for the kinetic energy, ejected mass and nickel mass in the explosion. The peak absolute magnitudes are, on average, brighter than those of similar supernovae (stripped-envelope supernovae) that do not have a gamma-ray burst association, but this can easily be due to a selection effect. However, the kinetic energies and ejected masses were found to be considerably higher, on average, than those of similar supernovae without a gamma-ray burst association.Comment: Accepted by AJ, 16 pages, 5 figure

A measure of nature connectedness for children and adults: Validation, performance, and insights

With benefits to both human well-being and pro-nature conservation behaviors, nature connectedness is emerging as an important psychological construct for a sustainable future. The growing research and applied and policy-related interests require a straightforward measure of nature connectedness that is suitable for both children and adult populations. To establish the reliability of the new Nature Connection Index (NCI) three factor analyses were conducted. One was based on a large Monitor of Engagement with the Natural Environment (MENE) dataset for adults (n = 3568) with a replication from data sets collected online (n = 553), and a third used MENE data from children (n = 351). To validate the NCI as a measure for nature connectedness an online comparison study (n = 153) included the NCI alongside other established measures. The results showed that the NCI was a reliable and valid scale that offers a short, simple alternative to other measures of nature connectedness, particularly for populations including both children and adults, measured face to face or online. The utility of the NCI is also supported, with variations associated with various pro-environmental and pro-conservation behaviors observed, and importantly the NCI also revealed changes in nature connectedness across the lifespan.N/

Streaming Algorithm for Euler Characteristic Curves of Multidimensional Images

We present an efficient algorithm to compute Euler characteristic curves of gray scale images of arbitrary dimension. In various applications the Euler characteristic curve is used as a descriptor of an image. Our algorithm is the first streaming algorithm for Euler characteristic curves. The usage of streaming removes the necessity to store the entire image in RAM. Experiments show that our implementation handles terabyte scale images on commodity hardware. Due to lock-free parallelism, it scales well with the number of processor cores. Our software---CHUNKYEuler---is available as open source on Bitbucket. Additionally, we put the concept of the Euler characteristic curve in the wider context of computational topology. In particular, we explain the connection with persistence diagrams

The nuclear pairing problem: new perspectives

The overview of the Exact Pairing technique based on the quasispin symmetry is presented. Extensions of this method are discussed in relation to mean field, quadrupole collectivity, electromagnetic transitions, and many-body level density. Realistic calculations compared with experimental data are used to support the methods as well as to emphasize the manifestations of pairing correlations in nuclear many-body systems.Comment: 10 pages, 5 figure

Absolute-Magnitude Distributions and Light Curves of Stripped-Envelope Supernovae

The absolute visual magnitudes of three Type IIb, 11 Type Ib and 13 Type Ic supernovae (collectively known as stripped-envelope supernovae) are studied by collecting data on the apparent magnitude, distance, and interstellar extinction of each event. Weighted and unweighted mean absolute magnitudes of the combined sample as well as various subsets of the sample are reported. The limited sample size and the considerable uncertainties, especially those associated with extinction in the host galaxies, prevent firm conclusions regarding differences between the absolute magnitudes of supernovae of Type Ib and Ic, and regarding the existence of separate groups of overluminous and normal-luminosity stripped-envelope supernovae. The spectroscopic characteristics of the events of the sample are considered. Three of the four overluminous events are known to have had unusual spectra. Most but not all of the normal luminosity events had typical spectra. Light curves of stripped-envelope supernovae are collected and compared. Because SN 1994I in M51 was very well observed it often is regarded as the prototypical Type Ic supernova, but it has the fastest light curve in the sample. Light curves are modeled by means of a simple analytical technique that, combined with a constraint on E/M from spectroscopy, yields internally consistent values of ejected mass, kinetic energy, and nickel mass.Comment: 39 pages, 14 figures, 7 tables; Accepted to A

Pairing correlations and transitions in nuclear systems

We discuss several pairing-related phenomena in nuclear systems, ranging from superfluidity in neutron stars to the gradual breaking of pairs in finite nuclei. We describe recent experimental evidence that points to a relation between pairing and phase transitions (or transformations) in finite nuclear systems. A simple pairing interaction model is used in order to study and classify an eventual pairing phase transition in finite fermionic systems such as nuclei. We show that systems with as few as 10-16 fermions can exhibit clear features reminiscent of a phase transition.Comment: Proceedings of COMEX1, Sorbonne, Paris, june 10-13 2003. To appear in Nuclear Physics

Home sampling for sexually transmitted infections and HIV in men who have sex with men: A prospective observational study

To determine uptake of home sampling kit (HSK) for STI/HIV compared to clinic-based testing, whether the availability of HSK would increase STI testing rates amongst HIV infected MSM, and those attending a community-based HIV testing clinic compared to historical control. Prospective observational study in three facilities providing STI/HIV testing services in Brighton, UK was conducted. Adult MSM attending/contacting a GUM clinic requesting an STI screen (group 1), HIV infectedMSM attending routine outpatient clinic (group 2), and MSM attending a community-based rapid HIV testing service (group 3) were eligible. Participants were required to have no symptomatology consistent with STI and known to be immune to hepatitis A and B (group 1). Eligiblemen were offered a HSK to obtain self-collected specimens as an alternative to routine testing. HSK uptake compared to conventional clinicbased STI/HIV testing in group 1, increase in STI testing rates due to availability of HSK compared to historical controls in group 2 and 3, and HSK return rates in all settings were calculated. Among the 128 eligible men in group 1, HSK acceptance was higher (62.5% (95%CI: 53.5-70.9)) compared to GUM clinic-based testing (37.5% (95% CI: 29.1-46.5)), (p = 0.0004). Two thirds of eligibleMSM offered an HSK in all three groups accepted it, but HSK return rates varied (highest in group 1, 77.5%, lowest in group 3, 16%). HSK for HIV testing was acceptable to 81%of men in group 1. Compared to historical controls, availability of HSK increased the proportion ofMSM testing for STIs in group 2 but not in group 3. HSK for STI/ HIV offers an alternative to conventional clinic-based testing for MSM seeking STI screening. It significantly increases STI testing uptake in HIV infected MSM. HSK could be considered as an adjunct to clinic-based services to further improve STI/HIV testing in MSM