862 research outputs found

    The bumpy light curve of supernova iPTF13z

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    A Type IIn supernova (SN) is dominated by the interaction of SN ejecta with the circumstellar medium (CSM). Some SNe IIn (e.g., SN 2006jd) have episodes of re-brightening ("bumps") in their light curves. We present iPTF13z, a SN IIn discovered by the intermediate Palomar Transient Factory (iPTF) and characterised by several bumps in its light curve. We analyse this peculiar behaviour trying to infer the properties of the CSM and of the SN explosion, as well as the nature of its progenitor star. We obtained multi-band optical photometry for over 1000 days after discovery with the P48 and P60 telescopes at Palomar Observatory. We obtained low-resolution optical spectra in the same period. We did an archival search for progenitor outbursts. We analyse our photometry and spectra, and compare iPTF13z to other SNe IIn. A simple analytical model is used to estimate properties of the CSM. iPTF13z was a SN IIn showing a light curve with five bumps during its decline phase. The bumps had amplitudes between 0.4 and 0.9 mag and durations between 20 and 120 days. The most prominent bumps appeared in all our different optical bands. The spectra showed typical SN IIn characteristics, with emission lines of Hα\alpha (with broad component FWHM ~103104  km s110^{3}-10^{4} ~{\rm ~km ~s^{-1}} and narrow component FWHM ~102 km s110^2 \rm ~km ~s^{-1}) and He I, but also with Fe II, Ca II, Na I D and Hβ\beta P-Cygni profiles (with velocities of ~10310^{3}  km s1{\rm ~km ~s^{-1}}). A pre-explosion outburst was identified lasting 50\gtrsim 50 days, with Mr15M_r \approx -15 mag around 210 days before discovery. Large, variable progenitor mass-loss rates (~> 0.01 M yr1M_{\odot} \rm ~yr^{-1}) and CSM densities (~> 1016^{-16} g cm3^{-3}) are derived. We suggest that the light curve bumps of iPTF13z arose from SN ejecta interacting with denser regions in the CSM, possibly produced by the eruptions of a luminous blue variable star.Comment: Version 2: Update to match published paper. 21 pages, 14 figures, abstract abridged to comply with arXiv length limit. In version 1 of the paper on arXiv, Table 3 had some erroneous entries. Table 3 is now corrected and available via VizieR. Version 1 comment: Accepted for publication in Astronomy & Astrophysics (24 pages, 14 figures, abstract abridged by 20 % not to exceed the arXiv length limit

    Metamorfosa Radikalisme pada Lembaga Pendidikan di Sulawesi Tenggara

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    Research on the metamorphosis of radicalism in educational institutions in Southeast Sulawesi has been conducted and focused on the segregation potential to be a radical individuals and groups to preach, especially in educational institutions in the Southeast Sulawesi. Data obtained through questionnaires, structured interviews, observation, document tracking and focus group discussion.The results showed that the metamorphosis of radicalism on the knot of educational institutions in Southeast Sulawesi spreading through the penetration movement in educational institutions such as on college campuses and in schools, especially in public campuses with the goal of lecturers and students and public schools targeted teachers and students. The spread on campus through student propaganda agency involving senior students and in the school and through extra-curricular involving senior students with methods of brainwashing. Lecturer plays an important role in the growth of radicalism as teachers and leaders of radical organizations with a method of indoctrination while teachers act through the hidden curriculum. The policy of the state budget subsidies to student organizations affiliated to the radical organization helped sustain the growth of radicalism on campus.The study recommends that efforts to break the chain of radicalism in educational institutions in Southeast Sulawesi can be done by educators either individually or as an educator together with governmen

    Holo-Omics:Integrated Host-Microbiota Multi-omics for Basic and Applied Biological Research

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    From ontogenesis to homeostasis, the phenotypes of complex organisms are shaped by the bidirectional interactions between the host organisms and their associated microbiota. Current technology can reveal many such interactions by combining multi-omic data from both hosts and microbes. However, exploring the full extent of these interactions requires careful consideration of study design for the efficient generation and optimal integration of data derived from (meta)genomics, (meta) transcriptomics, (meta)proteomics, and (meta)metabolomics. In this perspective, we introduce the holo-omic approach that incorporates multi-omic data from both host and microbiota domains to untangle the interplay between the two. We revisit the recent literature on biomolecular host-microbe interactions and discuss the im-plementation and current limitations of the holo-omic approach. We anticipate that the application of this approach can contribute to opening new research avenues and discoveries in biomedicine, biotechnology, agricultural and aquacultural sciences, nature conservation, as well as basic ecological and evolutionary research.The authors thank the following for funding their research: The Danish National Research Foundation award to M.T.P.G. (DNRF143), Villum Fonden grant to M.T. P.G. (17417), Lundbeckfonden grant to A.A. (R250-2017-1351), Danish Council for Independent Research grants to A.A. (DFF 5051-00033) and M.T.L. (DFF 8022-00005), ERC Consolidator Grant toM. T.P.G. (681396-Extinction Genomics), The Norwegian Seafood Research Fund -FHF grant to M.T.P.G. and M.T.L. (901436-HoloFish), H2020 Marie Sklodowska-Curie Individual Fellowship grant toM.T.L. (745723-HappyFish) and the European Union's Horizon 2020 Research and Innovation Programme grant to M.T.P.G., A.A. and M.T.L. (Grant Agreement No 817729 -HoloFood). Furthermore, the authors would like to thank Rob Dunn for his input and discussions

    Registration accuracy for MR images of the prostate using a subvolume based registration protocol

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    <p>Abstract</p> <p>Background</p> <p>In recent years, there has been a considerable research effort concerning the integration of magnetic resonance imaging (MRI) into the external radiotherapy workflow motivated by the superior soft tissue contrast as compared to computed tomography. Image registration is a necessary step in many applications, e.g. in patient positioning and therapy response assessment with repeated imaging. In this study, we investigate the dependence between the registration accuracy and the size of the registration volume for a subvolume based rigid registration protocol for MR images of the prostate.</p> <p>Methods</p> <p>Ten patients were imaged four times each over the course of radiotherapy treatment using a T2 weighted sequence. The images were registered to each other using a mean square distance metric and a step gradient optimizer for registration volumes of different sizes. The precision of the registrations was evaluated using the center of mass distance between the manually defined prostates in the registered images. The optimal size of the registration volume was determined by minimizing the standard deviation of these distances.</p> <p>Results</p> <p>We found that prostate position was most uncertain in the anterior-posterior (AP) direction using traditional full volume registration. The improvement in standard deviation of the mean center of mass distance between the prostate volumes using a registration volume optimized to the prostate was 3.9 mm (p < 0.001) in the AP direction. The optimum registration volume size was 0 mm margin added to the prostate gland as outlined in the first image series.</p> <p>Conclusions</p> <p>Repeated MR imaging of the prostate for therapy set-up or therapy assessment will both require high precision tissue registration. With a subvolume based registration the prostate registration uncertainty can be reduced down to the order of 1 mm (1 SD) compared to several millimeters for registration based on the whole pelvis.</p

    The long-lived Type IIn SN 2015da: Infrared echoes and strong interaction within an extended massive shell star star star

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    In this paper we report the results of the first similar to four years of spectroscopic and photometric monitoring of the Type IIn supernova SN 2015da (also known as PSN J13522411+3941286, or iPTF16tu). The supernova exploded in the nearby spiral galaxy NGC 5337 in a relatively highly extinguished environment. The transient showed prominent narrow Balmer lines in emission at all times and a slow rise to maximum in all bands. In addition, early observations performed by amateur astronomers give a very well-constrained explosion epoch. The observables are consistent with continuous interaction between the supernova ejecta and a dense and extended H-rich circumstellar medium. The presence of such an extended and dense medium is difficult to reconcile with standard stellar evolution models, since the metallicity at the position of SN 2015da seems to be slightly subsolar. Interaction is likely the mechanism powering the light curve, as confirmed by the analysis of the pseudo bolometric light curve, which gives a total radiated energy greater than or similar to 10(51) erg. Modeling the light curve in the context of a supernova shock breakout through a dense circumstellar medium allowed us to infer the mass of the prexisting gas to be similar or equal to 8 M-circle dot, with an extreme mass-loss rate for the progenitor star similar or equal to 0.6 M-circle dot yr(-1), suggesting that most of the circumstellar gas was produced during multiple eruptive events. Near- and mid-infrared observations reveal a fluxexcess in these domains, similar to those observed in SN 2010jl and other interacting transients, likely due to preexisting radiatively heated dust surrounding the supernova. By modeling the infrared excess, we infer a mass greater than or similar to 0.4 x 10(-3) M-circle dot for the dustSpanish MICINN gran

    IPEM Topical Report: an international IPEM survey of MRI use for external beam radiotherapy treatment planning

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    Introduction/Background: Despite growing interest in magnetic resonance imaging (MRI), integration in external beam radiotherapy (EBRT) treatment planning uptake varies globally. In order to understand the current international landscape of MRI in EBRT a survey has been performed in 11 countries. This work reports on differences and common themes identified. Methods: A multi-disciplinary Institute of Physics and Engineering in Medicine working party modified a survey previously used in the UK to understand current practice using MRI for EBRT treatment planning, investigate how MRI is currently used and managed as well as identify knowledge gaps. It was distributed electronically within 11 countries: Australia, Belgium, Denmark, Finland, France, Italy, the Netherlands, New Zealand, Sweden, the UK and the USA. Results: The survey response rate within the USA was <1% and hence these results omitted from the analysis. In the other 10 countries the survey had a median response rate of 77% per country. Direct MRI access, defined as either having a dedicated MRI scanner for radiotherapy (RT) or access to a radiology MRI scanner, varied between countries. France, Italy and the UK reported the lowest direct MRI access rates and all other countries reported direct access in ≥82% of centres. Whilst ≥83% of centres in Denmark and Sweden reported having dedicated MRI scanners for EBRT, all other countries reported ≤29%. Anatomical sites receiving MRI for EBRT varied between countries with brain, prostate, head and neck being most common. Commissioning and QA of image registration and MRI scanners varied greatly, as did MRI sequences performed, staffing models and training given to different staff groups. The lack of financial reimbursement for MR was a consistent barrier for MRI implementation for RT for all countries and MR access was a reported important barrier for all countries except Sweden and Denmark. Conclusion: No country has a comprehensive approach for MR in EBRT adoption and financial barriers are present worldwide. Variations between countries in practice, equipment, staffing models, training, QA and MRI sequences have been identified, and are likely to be due to differences in funding as well as a lack of consensus or guidelines in the literature. Access to dedicated MR for EBRT is limited in all but Sweden and Denmark, but in all countries there are financial challenges with ongoing per patient costs. Despite these challenges, significant interest exists in increasing MR guided EBRT planning over the next 5 years

    Socioeconomic inequalities in health among Swedish adolescents - adding the subjective perspective

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    Abstract Background Socioeconomic inequalities in adolescent health predict future inequalities in adult health. Subjective measures of socioeconomic status (SES) may contribute with an increased understanding of these inequalities. The aim of this study was to investigate socioeconomic health inequalities using both a subjective and an objective measure of SES among Swedish adolescents. Method Cross-sectional HBSC-data from 2002 to 2014 was used with a total sample of 23,088 adolescents aged 11–15 years. Three measures of self-rated health (dependent variables) were assessed: multiple health complaints, life satisfaction and health perception. SES was measured objectively by the Family Affluence Scale (FAS) and subjectively by “perceived family wealth” (independent variables). The trend for health inequalities was investigated descriptively with independent t-tests and the relationship between independent and dependent variables was investigated with multiple logistic regression analysis. Gender, age and survey year was considered as possible confounders. Results Subjective SES was more strongly related to health outcomes than the objective measure (FAS). Also, the relation between FAS and health was weakened and even reversed (for multiple health complaints) when subjective SES was tested simultaneously in regression models (FAS OR: 1.03, CI: 1.00;1.06 and subjective SES OR: 0.66, CI: 0.63;0.68). Conclusions The level of socioeconomic inequalities in adolescent health varied depending on which measure that was used to define SES. When focusing on adolescents, the subjective appraisals of SES is important to consider because they seem to provide a stronger tool for identifying inequalities in health for this group. This finding is important for policy makers to consider given the persistence of health inequalities in Sweden and other high-income countries
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