A note on adjoint error estimation for one-dimensional stationary balance laws with shocks

We consider one-dimensional steady-state balance laws with discontinuous solutions. Giles and Pierce realized that a shock leads to a new term in the adjoint error representation for target functionals.This term disappears if and only if the adjoint solution satisfies an internal boundary condition. Curiously, most computer codes implementing adjoint error estimation ignore the new term in the functional, as well as the internal adjoint boundary condition. The purpose of this note is to justify this omission as follows: if one represents the exact forward and adjoint solutions as vanishing viscosity limits of the corresponding viscous problems, then the internal boundary condition is naturally satisfied in the limit

Hohe Bildungsrenditen durch Vermeidung von Arbeitslosigkeit

Bildungsinvestitionen sind für den Einzelnen mit einem höheren Erwerbseinkommen und einem geringeren Arbeitslosigkeitsrisiko im Lebenszyklus verbunden. Eine Analyse auf Basis von Erwerbsbiografien des Sozio-oekonomischen Panels (SOEP) zeigt, dass die private Bildungsrendite, also der persönliche finanzielle Nutzen, unterschätzt wird, wenn man das durch Bildung gesunkene Arbeitslosigkeitsrisiko ignoriert. Die durchschnittlichen privaten und fiskalischen Bildungsrenditen liegen in Deutschland über der Verzinsung auf Investitionen in Realkapital. Bildungsinvestitionen erscheinen sowohl für den Einzelnen als auch für die Gesellschaft sinnvoll. Eine Ausweitung der staatlichen Bildungsfinanzierung würde also aus fiskalpolitischer Sicht Sinn ergeben, wie auch eine stärkere private Beteiligung an den Ausbildungskosten im tertiären Bildungsbereich. Voraussetzung dafür sind geeignete Modelle der Studierendenfinanzierung, etwa durch Stipendien oder Darlehen.Private returns to education, Fiscal returns, Unemployment

Synthesis and Structural Investigation of Protonated Haloacetyl Fluorides

Herein, we report the O-monoprotonated species of chloroacetyl fluoride and fluoroacetyl fluoride in the binary superacidic systems HF/MF5 and DF/MF5 (M=As, Sb) as hexafluoridoarsenates and hexafluoridostibates. The colorless salts were characterized by low temperature vibrational spectroscopy, low temperature NMR spectroscopy and single-crystal X-ray diffraction. [CCIH2C(OH)F][SbF6] crystallizes in the monoclinic space group P2(1)/c with four formula units per unit cell and [CIH2FC-(OD)F][SbF6] in the triclinic space group P (1) over bar with two formula units per cell. The experimental data are discussed together with quantum chemical calculations at the omega B97XD/aug-cc-pVTZ-level of theory. Protonation leads to significant shortening of the C F bond due to back-donation of fluorine lone-pair electrons

Spontaneous fluctuations of transition dipole moment orientation in OLED triplet emitters

The efficiency of an organic light-emitting diode (OLED) depends on the microscopic orientation of transition dipole moments of the molecular emitters. The most effective materials used for light generation have threefold symmetry, which prohibit a priori determination of dipole orientation due to the degeneracy of the fundamental transition. Single-molecule spectroscopy reveals that the model triplet emitter tris(2-phenylisoquinoline)iridium(III) (Ir(piq)3) does not behave as a linear dipole, radiating with lower polarization anisotropy than expected. Spontaneous symmetry breaking occurs in the excited state, leading to a random selection of one of the three ligands to form a charge transfer state with the metal. This non-deterministic localization is revealed in switching of the degree of linear polarization of phosphorescence. Polarization scrambling likely raises out-coupling efficiency and should be taken into account when deriving molecular orientation of the guest emitter within the OLED host from ensemble angular emission profiles

Lesion size and long-term cognitive outcome after pediatric stroke: A comparison between two techniques to assess lesion size.

BACKGROUND There is little consensus on how lesion size impacts long-term cognitive outcome after pediatric arterial ischemic stroke (AIS). This study, therefore, compared two techniques to assessed lesion size in the chronic phase after AIS and determined their measurement agreement in relation to cognitive functions in patients after pediatric stroke. METHODS Twenty-five patients after pediatric AIS were examined in the chronic phase (>2 years after stroke) in respect to intelligence, memory, executive functions, visuo-motor functions, motor abilities, and disease-specific outcome. Lesion size was measured using the ABC/2 formula and segmentation technique (3D Slicer). Correlation analysis determined the association between volumetry techniques and outcome measures in respect to long-term cognitive outcome. RESULTS The measurements from the ABC/2 and segmentation technique were strongly correlated (r = 0.878, p < .001) and displayed agreement in particular for small lesions. Lesion size from both techniques was significantly correlated with disease-specific outcome (p < .001) and processing speed (p < .005) after controlling for age at stroke and multiple comparison. CONCLUSION The two techniques showed convergent validity and were both significantly correlated with long-term outcome after pediatric AIS. Compared to the time-consuming segmentation technique, ABC/2 facilitates clinical and research work as it requires relatively little time and is easy to apply

Cognitive outcome is related to functional thalamo-cortical connectivity after paediatric stroke.

The thalamus has complex connections with the cortex and is involved in various cognitive processes. Despite increasing interest in the thalamus and the underlying thalamo-cortical interaction, little is known about thalamo-cortical connections after paediatric arterial ischaemic stroke. Therefore, the aim of this study was to investigate thalamo-cortical connections and their association with cognitive performance after arterial ischaemic stroke. Twenty patients in the chronic phase after paediatric arterial ischaemic stroke (≥2 years after diagnosis, diagnosed <16 years; aged 5-23 years, mean: 15.1 years) and 20 healthy controls matched for age and sex were examined in a cross-sectional study design. Cognitive performance (selective attention, inhibition, working memory, and cognitive flexibility) was evaluated using standardized neuropsychological tests. Resting-state functional magnetic resonance imaging was used to examine functional thalamo-cortical connectivity. Lesion masks were integrated in the preprocessing pipeline to ensure that structurally damaged voxels did not influence functional connectivity analyses. Cognitive performance (selective attention, inhibition, and working memory) was significantly reduced in patients compared to controls. Network analyses revealed significantly lower thalamo-cortical connectivity for the motor, auditory, visual, default mode network, salience, left/right executive, and dorsal attention network in patients compared with controls. Interestingly, analyses additionally revealed higher thalamo-cortical connectivity in some subdivisions of the thalamus for the default mode network (medial nuclei), motor (lateral nuclei), dorsal attention (anterior nuclei), and the left executive network (posterior nuclei) in patients compared with controls. Increased and decreased thalamo-cortical connectivity strength within the same networks was, however, found in different thalamic subdivisions. Thus, alterations in thalamo-cortical connectivity strength after paediatric stroke seem to point in both directions, with stronger as well as weaker thalamo-cortical connectivity in patients compared with controls. Multivariate linear regression, with lesion size and age as covariates, revealed significant correlations between cognitive performance (selective attention, inhibition, and working memory) and the strength of thalamo-cortical connectivity in the motor, auditory, visual, default mode network, posterior default mode network, salience, left/right executive, and dorsal attention network after childhood stroke. Our data suggest that the interaction between different sub-nuclei of the thalamus and several cortical networks relates to post-stroke cognition. The variability in cognitive outcomes after paediatric stroke might partly be explained by functional thalamo-cortical connectivity strength