1,500 research outputs found

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

    Get PDF
    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

    The role of defects in fluorescent silicon carbide layers grown by sublimation epitaxy

    Get PDF
    Donor-acceptor co-doped SiC is a promising light converter for novel monolithic all-semiconductor white LEDs due to its broad-band donor-acceptor pair luminescence and potentially high internal quantum efficiency. Besides sufficiently high doping concentrations in an appropriate ratio yielding short radiative lifetimes, long nonradiative lifetimes are crucial for efficient light conversion. The impact of different types of defects is studied by characterizing fluorescent silicon carbide layers with regard to photoluminescence intensity, homogeneity and efficiency taking into account dislocation density and distribution. Different doping concentrations and variations in gas phase composition and pressure are investigated

    Enhancement of PCA-based fault detection system through utilising dissimilarity matrix for continuous-based process

    Get PDF
    This research is about enhancement of PCA-based fault detection system through utilizing dissimilarity matrix. Nowadays, the chemical process industry is highly based on the non-linear relationships between measured variables. However, the conventional PCA-based MSPC is no longer effective because it only valid for the linear relationships between measured variables. Due in order to solve this problem, the technique of dissimilarity matrix is used in multivariate statistical process control as alternative technique which models the non-linear process and can improve the process monitoring performance. The conventional PCA system was run and the dissimilarity system was developed and lastly the monitoring performance in each technique were compared and analysed to achieve aims of this research. This research is to be done by using Matlab software. The findings of this study are illustrated in the form of Hotelling’s T2 and Squared Prediction Errors (SPE) monitoring statistics to be analysed. As a conclusion, the dissimilarity system is comparable to the conventional method. Thus can be the other alternative ways in the process monitoring performance. Finally, it is recommended to use data from other chemical processing systems for more concrete justification of the new technique

    Plasma Levels of Macrophage Migration Inhibitory Factor and d-Dopachrome Tautomerase Show a Highly Specific Profile in Early Life.

    Get PDF
    Macrophage migration inhibitory factor (MIF) is a pleiotropic, constitutively expressed, pro-inflammatory cytokine and an important regulator of immune responses. d-dopachrome tautomerase (DDT), a newly described member of the MIF protein superfamily, shares sequence homology and biological activities with MIF. We recently reported that high expression levels of MIF sustain innate immune responses in newborns. Here, we elected to further characterize age-dependent MIF expression and to define whether DDT shares a similar expression profile with MIF. Therefore, we delineated the circulating concentrations of MIF and DDT throughout life using a large cohort of 307 subjects including fetuses, newborns, infants, children, and adults. Compared to levels measured in healthy adults (median: 5.7 ng/ml for MIF and 16.8 ng/ml for DDT), MIF and DDT plasma concentrations were higher in fetuses (median: 48.9 and 29.6 ng/ml), increased further at birth (median: 82.6 and 52.0 ng/ml), reached strikingly elevated levels on postnatal day 4 (median: 109.5 and 121.6 ng/ml), and decreased to adult levels during the first months of life. A strong correlation was observed between MIF and DDT concentrations in all age groups (R = 0.91, P < 0.0001). MIF and DDT levels correlated with concentrations of vascular endothelial growth factor, a protein upregulated under low oxygen tension and implicated in vascular and lung development (R = 0.70, P < 0.0001 for MIF and R = 0.65, P < 0.0001 for DDT). In very preterm infants, lower levels of MIF and DDT on postnatal day 6 were associated with an increased risk of developing bronchopulmonary dysplasia and late-onset neonatal sepsis. Thus, MIF and DDT plasma levels show a highly specific developmental profile in early life, supporting an important role for these cytokines during the neonatal period

    Science and Film-making

    Get PDF
    The essay reviews the literature, mostly historical, on the relationship between science and film-making, with a focus on the science documentary. It then discusses the circumstances of the emergence of the wildlife making-of documentary genre. The thesis examined here is that since the early days of cinema, film-making has evolved from being subordinate to science, to being an equal partner in the production of knowledge, controlled by non-scientists

    Novel multiple sclerosis susceptibility loci implicated in epigenetic regulation

    Get PDF
    We conducted a genome-wide association study (GWAS) on multiple sclerosis (MS) susceptibility in German cohorts with 4888 cases and 10,395 controls. In addition to associations within the major histocompatibility complex (MHC) region, 15 non-MHC loci reached genome-wide significance. Four of these loci are novel MS susceptibility loci. They map to the genes L3MBTL3, MAZ, ERG, and SHMT1. The lead variant at SHMT1 was replicated in an independent Sardinian cohort. Products of the genes L3MBTL3, MAZ, and ERG play important roles in immune cell regulation. SHMT1 encodes a serine hydroxymethyltransferase catalyzing the transfer of a carbon unit to the folate cycle. This reaction is required for regulation of methylation homeostasis, which is important for establishment and maintenance of epigenetic signatures. Our GWAS approach in a defined population with limited genetic substructure detected associations not found in larger, more heterogeneous cohorts, thus providing new clues regarding MS pathogenesis

    Lobster Fishery Management in the Marine Ecosystem Approach at Simeulue Island Waters (Wpp-nri 572)

    Get PDF
    The lobster fishery is one of the leading fisheries commodity on Simeulue Regency so that local government must manage wisely in order to maintain the sustainability of the lobster fishery. Aceh Government Regulation namely Qanun Aceh No. 7 of 2010 concerning fisheries already in effect. However, the institutional system has not functioned optimally in the management of lobster fisheries. The purpose this study is to examine the domain of fishing techniques, socio-economic and institutional management of lobster fisheries with ecosystem approaches in Simeulue waters. Research method using qualitative research. The method of data collection is survey method which is done by purposive sampling approach that is by doing depth responder interview which is considered informative and wide knowledge about the institute. Data analysis using EAFM analysis done with Flag Modeling technique. Based on the results of the study that the assessment of the fishing domain techniques and economic domains in aggregate showed bad category. Meanwhile, social domains and institutional domains show moderate categories so aggregate composites overall show fewer categories. It is therefore necessary to make a tactical decision from the bad to be better in accordance with the category of each EAFM domain

    Mammal Mia: A review on how ecological and human dimension research on urban wild mammals can benefit future biophilic cities

    Get PDF
    Future cities have the potential to be biodiverse areas in which humans and wildlife can coexist. However, the success of creating or maintaining wildlife-inclusive future cities can be challenged by management actions that are solely based on ecological research, while overlooking research on human perspectives. Despite the growth of literature on human-wildlife interactions, which complements the breadth of urban ecology research, the overlap between these two research areas is still uncommon. In this study, we reviewed the literature of wild mammals in urban areas to identify patterns and gaps in the literature. We found 848 published journal articles, of which 480 articles focused on wildlife ecology, 269 articles focused on human dimensions and 99 articles had interdisciplinary combinations of both. Ecology-centered publications tended to be about habitat, rather than behavior, diet, health, reproduction and inter-species-relations, and literature on human dimensions was more evenly divided into management, perception, conflict and coexistence. Most ecology studies reported on specific taxonomic families, mainly canids and murids, but in human-dimension studies, “wildlife” was considered more as a general community of species. The most studied interdisciplinary combination of research themes was wildlife habitat and human-wildlife conflicts (n = 22), while only nine studies incorporated perception with ecological research. Even though studies on human dimensions of wildlife in cities are increasing, interdisciplinary research is lacking, which limits the knowledge on how to manage and shape urban areas to achieve coexistence of humans and wild mammals. For future cities to successfully become biophilic and support human-wildlife coexistence, we outlined five key elements for a research agenda: 1) Investigate urban mammal research through an interdisciplinary lens; 2) Explore ecological dynamics beyond habitat selection; 3) Conduct research for coexistence; 4) Disentangle what is “urban wildlife”; 5) Study a diverse array of urban wild mammals
    corecore