A Large Fraction of Hydrogen-rich Supernova Progenitors Experience Elevated Mass Loss Shortly Prior to Explosion

Spectroscopic detection of narrow emission lines traces the presence of circumstellar mass distributions around massive stars exploding as core-collapse supernovae. Transient emission lines disappearing shortly after the supernova explosion suggest that the material spatial extent is compact and implies an increased mass loss shortly prior to explosion. Here, we present a systematic survey for such transient emission lines (Flash Spectroscopy) among Type II supernovae detected in the first year of the Zwicky Transient Facility survey. We find that at least six out of ten events for which a spectrum was obtained within two days of the estimated explosion time show evidence for such transient flash lines. Our measured flash event fraction (>30% at 95% confidence level) indicates that elevated mass loss is a common process occurring in massive stars that are about to explode as supernovae

Photochemical internalisation of chemotherapy potentiates killing of multidrug-resistant breast and bladder cancer cells

Multidrug resistance (MDR) is the major confounding factor in adjuvant solid tumour chemotherapy. Increasing intracellular amounts of chemotherapeutics to circumvent MDR may be achieved by a novel delivery method, photochemical internalisation (PCI). PCI consists of the co-administration of drug and photosensitiser; upon light activation the latter induces intracellular release of organelle-bound drug. We investigated whether co-administration of hypericin (photosensitiser) with mitoxantrone (MTZ, chemotherapeutic) plus illumination potentiates cytotoxicity in MDR cancer cells. We mapped the extent of intracellular co-localisation of drug/photosensitiser. We determined whether PCI altered drug-excreting efflux pump P-glycoprotein (Pgp) expression or function in MDR cells. Bladder and breast cancer cells and their Pgp-overexpressing MDR subclones (MGHU1, MGHU1/R, MCF-7, MCF-7/R) were given hypericin/MTZ combinations, with/without blue-light illumination. Pilot experiments determined appropriate sublethal doses for each. Viability was determined by the 3-[4,5-dimethylthiazolyl]-2,5-diphenyltetrazolium bromide assay. Intracellular localisation was mapped by confocal microscopy. Pgp expression was detected by immunofluorescence and Pgp function investigated by Rhodamine123 efflux on confocal microscopy. MTZ alone (0.1–0.2 μg ml−1) killed up to 89% of drug-sensitive cells; MDR cells exhibited less cytotoxicity (6–28%). Hypericin (0.1–0.2 μM) effects were similar for all cells; light illumination caused none or minimal toxicity. In combination, MTZ /hypericin plus illumination, potentiated MDR cell killing, vs hypericin or MTZ alone. (MGHU1/R: 38.65 and 36.63% increase, P<0.05; MCF-7/R: 80.2 and 46.1% increase, P<0.001). Illumination of combined MTZ/hypericin increased killing by 28.15% (P<0.05 MGHU1/R) compared to dark controls. Intracytoplasmic vesicular co-localisation of MTZ/hypericin was evident before illumination and at serial times post-illumination. MTZ was always found in sensitive cell nuclei, but not in dark resistant cell nuclei. In illuminated resistant cells there was some mobilisation of MTZ into the nucleus. Pgp expression remained unchanged, regardless of drug exposure. Pgp efflux was blocked by the Pgp inhibitor verapamil (positive control) but not impeded by hypericin. The increased killing of MDR cancer cells demonstrated is consistent with PCI. PCI is a promising technique for enhancing treatment efficacy

The prevalence and influence of circumstellar material around hydrogen-rich supernova progenitors

Narrow transient emission lines (flash-ionization features) in early supernova (SN) spectra trace the presence of circumstellar material (CSM) around the massive progenitor stars of core-collapse SNe. The lines disappear within days after the SN explosion, suggesting that this material is spatially confined, and originates from enhanced mass loss shortly (months to a few years) prior to explosion. We performed a systematic survey of H-rich (Type II) SNe discovered within less than two days from explosion during the first phase of the Zwicky Transient Facility (ZTF) survey (2018-2020), finding thirty events for which a first spectrum was obtained within $< 2$ days from explosion. The measured fraction of events showing flash ionisation features ($>36\%$ at $95\%$ confidence level) confirms that elevated mass loss in massive stars prior to SN explosion is common. We find that SNe II showing flash ionisation features are not significantly brighter, nor bluer, nor more slowly rising than those without. This implies that CSM interaction does not contribute significantly to their early continuum emission, and that the CSM is likely optically thin. We measured the persistence duration of flash ionisation emission and find that most SNe show flash features for $\approx 5$ days. Rarer events, with persistence timescales $>10$ days, are brighter and rise longer, suggesting these may be intermediate between regular SNe II and strongly-interacting SNe IIn

The Prevalence and Influence of Circumstellar Material around Hydrogen-rich Supernova Progenitors

Narrow transient emission lines (flash-ionization features) in early supernova (SN) spectra trace the presence of circumstellar material (CSM) around the massive progenitor stars of core-collapse SNe. The lines disappear within days after the SN explosion, suggesting that this material is spatially confined, and originates from enhanced mass loss shortly (months to a few years) prior to the explosion. We performed a systematic survey of H-rich (Type II) SNe discovered within less than 2 days from the explosion during the first phase of the Zwicky Transient Facility survey (2018-2020), finding 30 events for which a first spectrum was obtained within 36% at the 95% confidence level) confirms that elevated mass loss in massive stars prior to SN explosion is common. We find that SNe II showing flash-ionization features are not significantly brighter, nor bluer, nor more slowly rising than those without. This implies that CSM interaction does not contribute significantly to their early continuum emission, and that the CSM is likely optically thin. We measured the persistence duration of flash-ionization emission and find that most SNe show flash features for ≈5 days. Rarer events, with persistence timescales >10 days, are brighter and rise longer, suggesting these may be intermediate between regular SNe II and strongly interacting SNe IIn

Annie, a Tool for Integrating Ergonomics in the Design of Car Interiors

An example of a result from a long-term cooperation with\ua0Lund University (together with professor Roland Axelsson at the Department\ua0for Work Environment) there some of the authors. (Engstr\uf6m)\ua0gained extensive\ua0grants (Wallenberg Stifelsen regarding\ua0equipment as well as other founding from e.g. the Swedish Work Environment Found)

ANNIE, a Tool for Integrating Ergonomics in the Design of Car Interiors

An example of a result from a long-term cooperation with\ua0Lund University (together with professor Roland Akselsson at the Department\ua0for Work Environment) there some of the authors (Engstr\uf6m)\ua0gained extensive\ua0grants (Wallenberg Stifelsen regarding\ua0equipment as well as other founding from e.g. the Swedish Work Environment Found). In this case the just mentioned EU-financing

Die Low-Cost-Hypothese: Theoretische Grundlagen und empirische Implikationen

Die Low-Cost-Hypothese (LCH) postuliert, dass der Einfluss von Einstellungen auf das Verhalten von der Kostenträchtigkeit der Entscheidungssituation abhängt. In Niedrigkostensituationen sei der Effekt der Einstellungen höher als in Hochkostensituationen. Wir argumentieren, dass bei genauerer Betrachtung der Literatur zwei verschiedene Versionen der LCH zu finden sind, die nicht ausreichend voneinander getrennt werden. Wir rekonstruieren diese beiden Versionen, die "einfache" und die "spezifische" Version der LCH, und diskutieren ihre theoretischen Grundlagen und empirischen Implikationen. Die "einfache" Version ergibt sich aus einer einfachen nutzentheoretischen Modellierung des Entscheidungsproblems. In dieser Version der LCH wirken Einstellungen und (harte) Verhaltenskosten unabhängig voneinander auf den Netto-Erwartungsnutzen der Handlungsalternativen. Ein bedingter Effekt der Einstellungen in Abhängigkeit von den Verhaltenskosten ergibt sich lediglich in Bezug auf die Wahrscheinlichkeit der Wahl einer Handlungsalternativen. Diese Abhängigkeit der marginalen Effekte von dem Nutzenniveau oder der Basiswahrscheinlichkeit, auf der ein Akteur sich befindet, gilt jedoch für alle möglichen Einflussfaktoren oder Nutzenterme. Eine zweite, "spezifische" Version der LCH postuliert darüber hinausgehend einen variablenspezifischen Interaktionseffekt zwischen Einstellungen und Kosten. Während die meisten der zur Herleitung dieser Hypothese vorgebrachten Ansätze bei näherer Betrachtung unzureichend sind, bieten dual-process-Theorien eine Möglichkeit, die spezifische Version der LCH handlungstheoretisch zu fundieren und in ihrer bedingten Gültigkeit zu verstehen. Aus dem Beitrag ergeben sich sowohl Schlussfolgerungen für empirische Anwendungen und Tests der LCH in diversen soziologischen Forschungsgebieten als auch generell für die entscheidungstheoretische Analyse sozialen Handelns