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Global, three-dimensional simulations of rapidly rotating massive stars show that turbulence driven by magnetohydrodynamic instability is a promising mechanism for the formation of pulsars and magnetars, the latter potentially powering hyperenergetic and superluminous supernovae. Strong magnetic fields as drivers for supernovae Some of the most energetic of astrophysical systems derive their energy from magnetohydrodynamic turbulence. Philipp MÖsta et al . report results from global three-dimensional general-relativistic magnetohydrodynamic turbulence simulations and show that magnetorotational instability is highly effective in driving magnetohydrodynamic turbulence, which in combination with rotation leads to an inverse cascade (dynamo) and generates an ordered magnetic field at large scales. The results demonstrate that rapidly rotating massive stars are plausible progenitors for both type Ic-bl supernovae and long γ-ray bursts, present a viable formation mechanism for magnetars, and may account for potentially magnetar-powered superluminous supernovae. Magnetohydrodynamic turbulence is important in many high-energy astrophysical systems, where instabilities can amplify the local magnetic field over very short timescales 1 , 2 . Specifically, the magnetorotational instability and dynamo action 3 , 4 , 5 , 6 have been suggested as a mechanism for the growth of magnetar-strength magnetic fields (of 10 15 gauss and above) and for powering the explosion 7 , 8 , 9 , 10 of a rotating massive star 11 , 12 . Such stars are candidate progenitors of type Ic-bl hypernovae 13 , 14 , which make up all supernovae that are connected to long γ-ray bursts 15 , 16 . The magnetorotational instability has been studied with local high-resolution shearing-box simulations in three dimensions 17 , 18 , 19 , and with global two-dimensional simulations 20 , but it is not known whether turbulence driven by this instability can result in the creation of a large-scale, ordered and dynamically relevant field. Here we report results from global, three-dimensional, general-relativistic magnetohydrodynamic turbulence simulations. We show that hydromagnetic turbulence in rapidly rotating protoneutron stars produces an inverse cascade of energy. We find a large-scale, ordered toroidal field that is consistent with the formation of bipolar magnetorotationally driven outflows. Our results demonstrate that rapidly rotating massive stars are plausible progenitors for both type Ic-bl supernovae 13 , 21 , 22 and long γ-ray bursts, and provide a viable mechanism for the formation of magnetars 23 , 24 . Moreover, our findings suggest that rapidly rotating massive stars might lie behind potentially magnetar-powered superluminous supernovae 25 , 26 .

We present an approach for kinesthetic teaching of motion primitives for a humanoid robot. The proposed teaching method starts with observational learning and applies iterative kinesthetic motion refinement using a forgetting factor. Kinesthetic teaching is supported by introducing the motion refinement tube, which represents an area of allowed motion refinement around the nominal trajectory. On the realtime control level, the kinesthetic teaching is handled by a customized impedance controller, which combines tracking performance with compliant physical interaction and allows to implement soft boundaries for the motion refinement. A novel method for continuous generation of motions from a hidden Markov model (HMM) representation of motion primitives is proposed, which incorporates time information for each state. The proposed methods were implemented and tested using DLR’s humanoid upper-body robot Justin.

Symmetric Lorentzian and asymmetric Fano line shapes are fundamental spectroscopic signatures that quantify the structural and dynamical properties of nuclei, atoms, molecules, and solids. This study introduces a universal temporal-phase formalism, mapping the Fano asymmetry parameter q to a phase φ of the time-dependent dipole response function. The formalism is confirmed experimentally by laser-transforming Fano absorption lines of autoionizing helium into Lorentzian lines after attosecond-pulsed excitation. We also demonstrate the inverse, the transformation of a naturally Lorentzian line into a Fano profile. A further application of this formalism uses quantum-phase control to amplify extreme-ultraviolet light resonantly interacting with He atoms. The quantum phase of excited states and its response to interactions can thus be extracted from line-shape analysis, with applications in many branches of spectroscopy.

The dynamics of two correlated electrons can be reconstructed from the quantum interference of low-lying doubly excited states in helium, as observed in attosecond transient-absorption spectra, and can be controlled by tuning the interaction with a visible laser field of variable intensity. Two-electron motion probed Although the concerted motion of two or more bound electrons controls all chemical reactions, understanding and probing of such electron dynamics remains challenging. The motion of single electrons has been observed with attosecond time resolution, but comparable experiments on two-electron motion have not yet been realized. Christian Ott and colleagues now show that the dynamics of two correlated electrons in helium can be reconstructed from attosecond transient-absorption spectra measured with unprecedented high spectral resolution and in the presence of an intensity-tuneable visible laser field. Future experiments using the same approach are expected to provide benchmark data for testing theory, and might even make it possible to probe metastable electronic transition states that are at the heart of fundamental chemical reactions. The concerted motion of two or more bound electrons governs atomic 1 and molecular 2 , 3 non-equilibrium processes including chemical reactions, and hence there is much interest in developing a detailed understanding of such electron dynamics in the quantum regime. However, there is no exact solution for the quantum three-body problem, and as a result even the minimal system of two active electrons and a nucleus is analytically intractable 4 . This makes experimental measurements of the dynamics of two bound and correlated electrons, as found in the helium atom, an attractive prospect. However, although the motion of single active electrons and holes has been observed with attosecond time resolution 5 , 6 , 7 , comparable experiments on two-electron motion have so far remained out of reach. Here we show that a correlated two-electron wave packet can be reconstructed from a 1.2-femtosecond quantum beat among low-lying doubly excited states in helium. The beat appears in attosecond transient-absorption spectra 5 , 7 , 8 , 9 measured with unprecedentedly high spectral resolution and in the presence of an intensity-tunable visible laser field. We tune the coupling 10 , 11 , 12 between the two low-lying quantum states by adjusting the visible laser intensity, and use the Fano resonance as a phase-sensitive quantum interferometer 13 to achieve coherent control of the two correlated electrons. Given the excellent agreement with large-scale quantum-mechanical calculations for the helium atom, we anticipate that multidimensional spectroscopy experiments of the type we report here will provide benchmark data for testing fundamental few-body quantum dynamics theory in more complex systems. They might also provide a route to the site-specific measurement and control of metastable electronic transition states that are at the heart of fundamental chemical reactions.

Impedance Control and Admittance Control are two distinct implementations of the same control goal but their stability and performance characteristics are complementary. Impedance Control is better suited for dynamic interaction with stiff environments and Admittance Control is better suited for interaction with soft environments or operation in free space. In this paper, we use a hybrid systems framework to develop an entire family of controllers that have Impedance Control and Admittance Control at two ends of its spectrum; and intermediate controllers that have stability and performance characteristics that are an interpolation of those of Impedance Control and Admittance Control. The hybrid systems framework provides the scope for maintaining stability and achieving the best performance by choosing a specific controller for a given environment and by continuously changing the controller to adapt to a changing environment. The advantage of our approach is demonstrated with an extensive case study of a one-dimensional system and through experiments with the joint of a lightweight robotic arm.

Background Empagliflozin has been shown to reduce cardiovascular mortality, but the underlying pathogenetic mechanisms are poorly understood. It was previously demonstrated that empagliflozin improved arterial stiffness. Methods Our analysis comprising 58 patients with type 2 diabetes mellitus identifies factors triggering the improvement of arterial stiffness. All patients participated in an investigator-initiated, prospective, double-blind, randomized, placebo-controlled, interventional clinical trial ( http://www.ClinicalTrials.gov : NCT02471963, registered 15th June 2015, retrospectively registered) and received either 6-weeks treatment with 25 mg empagliflozin orally once daily or placebo (crossover). Central systolic pressure and central pulse pressure were recorded by the SphygmoCor System (AtCor Medical). Now, we investigated the impact of parameters of glucose metabolism, volume status, sympathetic activation, lipids, uric acid, blood pressure and inflammation on vascular parameters of arterial stiffness using multivariate regression analysis. Results As previously reported, therapy with empagliflozin improved arterial stiffness as indicated by reduced central systolic blood pressure (113.6 ± 12.1 vs 118.6 ± 12.9 mmHg, p < 0.001), central pulse pressure (39.1 ± 10.2 vs 41.9 ± 10.7 mmHg, p = 0.027) forward (27.1 ± 5.69 vs 28.7 ± 6.23 mmHg, p = 0.031) as well as reflected wave amplitude (18.9 ± 5.98 vs 20.3 ± 5.97 mmHg, p = 0.045) compared to placebo. The multivariate regression analysis included age, sex and change between empagliflozin and placebo therapy of the following parameters: HbA1c, copeptin, hematocrit, heart rate, LDL-cholesterol, uric acid, systolic 24-h ambulatory blood pressure and high sensitive CRP (hsCRP). Besides the influence of age (beta = − 0.259, p = 0.054), sex (beta = 0.292, p = 0.040) and change in systolic 24-h ambulatory blood pressure (beta = 0.364, p = 0.019), the change of hsCRP (beta = 0.305, p = 0.033) emerged as a significant determinant of the empagliflozin induced reduction in arterial stiffness (placebo corrected). When replacing HbA1c with fasting plasma glucose in the multivariate regression analysis, a similar effect of the change in hsCRP (beta = 0.347, p = 0.017) on arterial stiffness parameters was found. Conclusion Besides age and sex, change in systolic 24-h ambulatory blood pressure and change in hsCRP were determinants of the empagliflozin induced improvement of vascular parameters of arterial stiffness, whereas parameters of change in glucose metabolism and volume status had no significant influence. Our analysis suggests that empagliflozin exerts, at least to some extent, its beneficial vascular effects via anti-inflammatory mechanisms. Trial registration http://www.ClinicalTrials.gov : NCT02471963, registered 15th June 2015, retrospectively registered

BackgroundHypertension is poorly controlled in numerous patients despite effective medication being available. Catheter-based renal denervation (RDN) has emerged as an alternative treatment option. We aimed to assess how likely patients with elevated blood pressure (BP) are to accept RDN as treatment option.MethodsA questionnaire-based cross-sectional survey was performed in patients with elevated BP in Germany. Data on patient demographics, clinical characteristics and treatment preferences were collected, anonymized and analyzed.ResultsOne thousand and eleven patients completed the survey. Mean age was 66 years (55% male). If not already on medication (n = 172), 38.2% of patients would prefer RDN. Of those already on drug therapy (n = 839), 28.2% would opt for RDN. Patients who were pro-RDN were younger (p < 0.0001) and more often male (p < 0.0001). Nineteen percent would choose RDN if it lowered systolic BP by at least 20 mmHg, more than 40% if they did not have to take any more pills thereafter, and 30% if it would lower BP by at least 10 mmHg. Experiences of side effects and drug adherence were identified as determinants of patient preference. Physicians were the main source of information regarding medical problems (95.5%) and influence patients’ decision regarding therapies (98%).ConclusionsThis survey found that a significant proportion of patients would choose catheter-based RDN over lifelong pharmacotherapy. These patients were younger and more likely to be male but their expectation of the extent of BP decrease with RDN was high. Physicians are key mediators for treatment selection. They need to incorporate patient preferences into shared decision making.

Mie scattering is an optical phenomenon that appears when electromagnetic waves, in particular light, are elastically scattered at a spherical or cylindrical object. A transfer of this phenomenon onto electron states in ballistic graphene has been proposed theoretically, assuming a well-defined incident wave scattered by a perfectly cylindrical nanometer scaled potential, but experimental fingerprints are lacking. We present an experimental demonstration of an electrical analogue to Mie scattering by using graphene as a conductor, and circular potentials arranged in a square two-dimensional array. The tabletop experiment is carried out under seemingly unfavourable conditions of diffusive transport at room-temperature. Nonetheless, when a canted arrangement of the array with respect to the incident current is chosen, cascaded Mie scattering results robustly in a transverse voltage. Its response on electrostatic gating and variation of potentials convincingly underscores Mie scattering as underlying mechanism. The findings presented here encourage the design of functional electronic metamaterials. Until now experimental evidence of an electrical analogy to Mie scattering is lacking. Here, Caridad and Krstić et al . present an experimental demonstration of an electrical analogue to Mie scattering by using graphene as conductor, and circular potentials arranged in a canted two-dimensional array.

In patients with type 2 diabetes mellitus (T2DM) arterial stiffness is associated with increased cardiovascular and total mortality. Little is known about determinants of arterial stiffness in clinical routine. Identification of potential determinants of arterial stiffness will help to address treatment targets for patients in the early state of T2DM. This is a cross-sectional analysis of arterial stiffness in 266 patients in the early stage of T2DM who did not have cardiovascular or renal complications. Parameters of arterial stiffness such as central systolic blood pressure (cSBP), central pulse pressure (cPP) and pulse wave velocity (PWV) were measured with the SphygmoCor System (AtCor Medical). We investigated the influence of parameters of glucose metabolism, lipid status, body constitution, blood pressure (BP) and inflammation on the stiffness parameters using multivariate regression analysis. The study cohort consisted of male and female patients aged 61 ± 8 years with mean diabetes duration of 6.4 ± 5.1 years, mean HbA1c 7.1 ± 0.9%, mean cSBP 121 ± 12 mmHg, mean cPP 44 ± 10 mmHg and mean PWV 8.9 ± 1.8 m/s. Multiple regression analysis identified waist circumference (WC) (beta = 0.411, p = 0.026), LDL-cholesterol (beta = 0.106, p = 0.006), systolic office BP (beta = 0.936, p < 0.001) and diabetes duration (beta = 0.233, p = 0.043) as potential determinants of cSBP. cPP was determined by sex (beta = 0.330, p = 0.008), age (beta = 0.383, p < 0.001), systolic office BP (beta = 0.370, p < 0.001) and diabetes duration (beta = 0.231, p = 0.028) whereas for PWV the following determinants could be identified: age (beta = 0.405, p < 0.001), systolic office BP (beta = 0.421, p < 0.001) and diabetes duration (beta = 0.073, p = 0.038). In addition to the known parameters age, sex and systolic office BP serum LDL-cholesterol, WC and diabetes duration have been identified as determinants of arterial stiffness in patients with T2DM. Treatment of patients in the early stage of T2DM should focus on these clinical parameters to prevent progression of arterial stiffness and as a consequence reduce cardiovascular mortality. Trial registration: The patients included in the analysis participated in one of the following clinical trials NCT02752113 (registered 26.4.2016), NCT02383238 (09.03.2015), NCT02471963 (15.06.2015), NCT01319357 (21.03.2011) ( http://www.clinicaltrials.gov ).

PurposeThe purpose of this study is to investigate to what extent the professional identity of accountants, as manifested in a set of advanced cognitive, emotional and social intelligence competencies relevant to their professional activities, varies with the respective accounting position.Design/methodology/approachThe systematically developed, formally clearly structured job advertisements for accounting positions provide content-rich representations of those holding the advertised position and thus contribute to revealing the professional identity. This study conducts a content analysis of 600 profiles of accountants presented in job advertisements of German organizations to identify the characteristic set of advanced cognitive, emotional and social intelligence competencies, juxtaposing different accounting positions at various stages of professional life. German organizations were targeted because they traditionally clearly differentiate between financial accounting and management accounting.FindingsThe job advertisements suggest that accountants develop a multifaceted professional identity reflecting their area of specialization and their level of entry. Financial accountants are more likely to be team-oriented than management accountants, and non-executive accountants are more likely than executive accountants. Analytical thinking seems to characterize management accountants rather than financial accountants. An independent way of working appears to be more pronounced among financial accountants than among management accountants.Originality/valueThis study refines the understanding of the professional identity of accountants by exploring the recruitment of accountants, the initial step of professional socialization. It identifies the most relevant advanced cognitive, emotional and social intelligence competencies based on a broad sample of job advertisements for accounting positions in organizations of different sizes and industries. By contrasting the competencies relevant to different positions and at different stages of their professional lives, it becomes evident that distinct professional identities of accountants coexist. The relevant competencies may be developed during higher education and continuing professional education. They may also be incorporated into individual performance evaluations and used as the basis for promotion decisions.