Measuring the core rotation of red giant stars

Red giant stars present mixed modes, which behave as pressure modes in the convective envelope and as gravity modes in the radiative interior. This mixed character allows to probe the physical conditions in their core. With the advent of long-duration time series from space-borne missions such as CoRoT and Kepler, it becomes possible to study the red giant core rotation. As more than 15 000 red giant light curves have been recorded, it is crucial to develop a robust and efficient method to measure this rotation. Such measurements of thousands of mean core rotation would open the way to a deeper understanding of the physical mechanisms that are able to transport angular momentum from the core to the envelope in red giants. In this work, we detail the principle of the method we developed to obtain automatic measurements of the red giant mean core rotation. This method is based on the stretching of the oscillation spectra and on the use of the so-called Hough transform. We finally validate this method for stars on the red giant branch, where overlapping rotational splittings and mixed-mode spacings produce complicated frequency spectra.Comment: 8 pages, 3 figures, 1 tabl

Rapidly rotating red giants

Stellar oscillations give seismic information on the internal properties of stars. Red giants are targets of interest since they present mixed modes, which behave as pressure modes in the convective envelope and as gravity modes in the radiative core. Mixed modes thus directly probe red giant cores, and allow in particular the study of their mean core rotation. The high-quality data obtained by CoRoT and Kepler satellites represent an unprecedented perspective to obtain thousands of measurements of red giant core rotation, in order to improve our understanding of stellar physics in deep stellar interiors. We developed an automated method to obtain such core rotation measurements and validated it for stars on the red giant branch. In this work, we particularly focus on the specific application of this method to red giants having a rapid core rotation. They show complex spectra where it is tricky to disentangle rotational splittings from mixed-mode period spacings. We demonstrate that the method based on the identification of mode crossings is precise and efficient. The determination of the mean core rotation directly derives from the precise measurement of the asymptotic period spacing {\Delta}{\Pi}1 and of the frequency at which the crossing of the rotational components is observed.Comment: 4 pages, 2 figures, 2 tables, to be published in the Astro Fluid 2016 Conference Proceedings, editor EAS Publications Serie

Accounting for changes in biodiversity and ecosystem services from a business perspective

Biodiversity refers to the dynamics of interactions between organisms in changing environments. Within the context of accelerating biodiversity loss worldwide, firms are under increasing pressures from stakeholders to develop appropriate tools to account for the nature and consequences of their actions, inclusive of their influences on ecosystem services used by other agents. This paper presents a two-pronged approach towards accounting for changes in biodiversity and ecosystem services from a business perspective. First, we seek to analyze how Environmental Management Accounting (EMA) may be used by firms to identify and account for the interactions between their activities and biodiversity and ecosystem services (BES). To that end, we use dairy farming as a case study and propose general recommendations regarding accounting for changes in biodiversity and ecosystem services from a management accounting perspective. Secondly, after discussing the corporate reporting implications of the main environmental accounting approaches, we propose the underlying principles and structural components of a Biodiversity Accountability Framework (BAF) which would combine both financial and BES data sets; hence, suggesting the need for changes in business accounting and reporting standards. Because this would imply significant changes in business information systems and corporate rating practices, we also underline the importance of making the associated technological, organizational and institutional innovations financially viable. The BAF should be designed as an information base, coconstructed with stakeholders, for setting up and managing new modes of regulation combining tools for mitigating BES loss and remunerating BES supply.Accounting, business, biodiversity, ecosystem services, indicators, management accounting, financial accounting, reporting, corporate social responsibility, standards, biodiversity accountability framework.

Stable climate and surface mass balance in Svalbard over 1979–2013 despite the Arctic warming

With the help of the regional climate model MAR (Modèle Atmosphérique Régional) forced by the ERA-Interim reanalysis (MARERA) and the MIROC5 (Model for Interdisciplinary Research on Climate) global model (MARMIROC5) from the CMIP5 (Coupled Model Intercomparison Project) database, we have modelled the climate and surface mass balance of Svalbard at a 10 km resolution over 1979–2013. The integrated total surface mass balance (SMB) over Svalbard modelled by MARERA is negative (−1.6 Gt yr−1) with a large interannual variability (7.1 Gt) but, unlike over Greenland, there has been no acceleration of the surface melt over the past 35 years because of the recent change in atmospheric circulation bringing northwesterly flows in summer over Svalbard, contrasting the recent observed Arctic warming. However, in 2013, the atmospheric circulation changed to a south–southwesterly flow over Svalbard causing record melt, SMB (−20.4 Gt yr−1) and summer temperature. MIROC5 is significantly colder than ERA-Interim over 1980–2005 but MARMIROC5 is able to improve the near-surface MIROC5 results by simulating not significant SMB differences with MARERA over 1980–2005. On the other hand, MIROC5 does not represent the recent atmospheric circulation shift in summer and induces in MARMIROC5 a significant trend of decreasing SMB (−0.6 Gt yr−2) over 1980–2005

Isotope shift in the Sulfur electron affinity: observation and theory

The electron affinities eA(S) are measured for the two isotopes 32S and 34S (16752.9753(41) and 16752.9776(85) cm-1, respectively). The isotope shift in the electron affinity is found to be positive, eA(34S)-eA(32S) = +0.0023(70) cm-1, but the uncertainty allows for the possibility that it may be either "normal" (eA(34S) > eA(32S)) or "anomalous" (eA(34S) < eA(32S)). The isotope shift is estimated theoretically using elaborate correlation models, monitoring the electron affinity and the mass polarization term expectation value. The theoretical analysis predicts a very large specific mass shift that counterbalances the normal mass shift and produces an anomalous isotope shift, eA(34S)-eA(32S) = - 0.0053(24) cm-1. The observed and theoretical residual isotope shifts agree with each other within the estimated uncertainties.Comment: 15 pages, 4 figure

Human Urinary Bladder Strip Relaxation by the β-Adrenoceptor Agonist Isoprenaline: Methodological Considerations and Effects of Gender and Age

The present study was primarily designed to explore various methodological aspects related to organ bath experiments evaluating human detrusor relaxation by the β-adrenoceptor agonist isoprenaline. Data are based upon a series of 30 consecutive patients, and this cohort was also used to explore possible effects of gender and age. KCl-induced contraction was related to strip length but not weight or cross-sectional area, indicating that the former is most suitable for data normalization. Storage of detrusor strips in cold buffer for up to 2 days did not affect contractile responses to KCl or efficacy of isoprenaline to cause relaxation but significantly affected the isoprenaline potency. No such alterations were observed with up to 1 day of cold storage. The type (KCl vs. passive tension) or strength of contractile stimulus had only minor effects on isoprenaline responses although these differences reached statistical significance in some cases. Similarly, gender and age had only minor if any effects on KCl-induced contraction or isoprenaline-induced relaxation, but the current data are too limited for robust conclusions. In summary we have evaluated experimental conditions for the testing of human detrusor strip contraction and relaxation which should be useful for future larger studies

Accounting for changes in biodiversity and ecosystem services from a business perspective: Preliminary guidelines towards a biodiversity accountability framework

Biodiversity refers to the dynamics of interactions between organisms in changing environments. Within the context of accelerating biodiversity loss worldwide, firms are under increasing pressures from stakeholders to develop appropriate tools to account for the nature and consequences of their actions, inclusive of their influences on ecosystem services used by other agents. This paper presents a two-pronged approach towards accounting for changes in biodiversity and ecosystem services from a business perspective. First, we seek to analyze how Environmental Management Accounting (EMA) may be used by firms to identify and account for the interactions between their activities and biodiversity and ecosystem services (BES). To that end, we use dairy farming as a case study and propose general recommendations regarding accounting for changes in biodiversity and ecosystem services from a management accounting perspective. Secondly, after discussing the corporate reporting implications of the main environmental accounting approaches, we propose the underlying principles and structural components of a Biodiversity Accountability Framework (BAF) which would combine both financial and BES data sets; hence, suggesting the need for changes in business accounting and reporting standards. Because this would imply significant changes in business information systems and corporate rating practices, we also underline the importance of making the associated technological, organizational and institutional innovations financially viable. The BAF should be designed as an information base, coconstructed with stakeholders, for setting up and managing new modes of regulation combining tools for mitigating BES loss and remunerating BES supply