An adaptive grid refinement strategy for the simulation of negative streamers

The evolution of negative streamers during electric breakdown of a non-attaching gas can be described by a two-fluid model for electrons and positive ions. It consists of continuity equations for the charged particles including drift, diffusion and reaction in the local electric field, coupled to the Poisson equation for the electric potential. The model generates field enhancement and steep propagating ionization fronts at the tip of growing ionized filaments. An adaptive grid refinement method for the simulation of these structures is presented. It uses finite volume spatial discretizations and explicit time stepping, which allows the decoupling of the grids for the continuity equations from those for the Poisson equation. Standard refinement methods in which the refinement criterion is based on local error monitors fail due to the pulled character of the streamer front that propagates into a linearly unstable state. We present a refinement method which deals with all these features. Tests on one-dimensional streamer fronts as well as on three-dimensional streamers with cylindrical symmetry (hence effectively 2D for numerical purposes) are carried out successfully. Results on fine grids are presented, they show that such an adaptive grid method is needed to capture the streamer characteristics well. This refinement strategy enables us to adequately compute negative streamers in pure gases in the parameter regime where a physical instability appears: branching streamers.Comment: 46 pages, 19 figures, to appear in J. Comp. Phy

Irrelevant tactile stimulation biases visual exploration in external coordinates

Ossandón JP, König P, Heed T. Irrelevant tactile stimulation biases visual exploration in external coordinates. Scientific Reports. 2015;5(1): 10664

Mechanisms bywhich dietary fatty acids regulate mitochondrial structure-function in health and disease

Mitochondria are the energy-producing organelles within a cell. Furthermore, mitochondria have a role in maintaining cellular homeostasis and proper calcium concentrations, building critical components of hormones and other signaling molecules, and controlling apoptosis. Structurally, mitochondria are unique because they have 2 membranes that allow for compartmentalization. The composition and molecular organization of thesemembranes are crucial to the maintenance and function of mitochondria. In this review, we first present a general overview of mitochondrial membrane biochemistry and biophysics followed by the role of different dietary saturated and unsaturated fatty acids in modulatingmitochondrial membrane structure-function.We focus extensively on long-chain n-3 (ω-3) polyunsaturated fatty acids and their underlyingmechanisms of action. Finally,we discuss implications of understanding molecular mechanisms by which dietary n-3 fatty acids targetmitochondrial structure-function in metabolic diseases such as obesity, cardiac-ischemia reperfusion injury, obesity, type 2 diabetes, nonalcoholic fatty liver disease, and select cancers

Schreiben eines Vaters an seinen Sohn, von der Heiligkeit der Archive

[Gottlieb Schumann]Nicht identisch mit VD18 10564411, dort: abweichender Umfang 23 S. und anderer FingerprintVorlageform des Erscheinungsvermerks: 1756

De Doctrina Prvdentiae Civilis Pvblicae In Academiis

Leipzig, Univ., Phil. Disp., 1750Pro Loco In Amplissima Facvltate Philosophica Obtinendo Ad D. 30 Septemb. A. MDCCL. Primvm Dispvtabit M. Gottlieb Schvmann, Gorlic. Lvsat.Nicht identisch mit VD18 11600632, dort: "Ad D. 3. Octobr. A. MDCCL."Vorlageform des Erscheinungsvermerks: Lipsiae, Apvd Geo. Wilh. Pouillard

Die Gerechte Sache Chur-Sachsens

[Gottlieb Schumann]Nicht identisch mit VD18 14847485, VD18 90395379, VD18 90395336, VD18 90395344, VD18 9039531X, VD18 90299787 und VD18 90209168, dort: ohne Zierstück auf dem Titelblatt; nicht identisch mit VD18 90399269, dort Rückseite des Titelblattes unbedruckt; nicht identisch mit VD18 14820412, dort abweichender Umfang 12 S.Vorlageform des Erscheinungsvermerks: Erfurt, im November 1756

Die Gerechte Sache Chur-Sachßens

[Gottlieb Schumann]Nicht ident. mit VD18 14820412, dort: Zierstück auf Titelblatt und Umfang 12 S.; nicht ident. mit VD18 14847485, dort: auf Titelblatt Die Gerechte Sache Chur-Sachsen; nicht ident.mit VD18 10584595, dort mit beigefügten WerkAutopsie nach Exemplar der ULB Sachsen-AnhaltVorlageform des Erscheinungsvermerks: Erfurt, im November 175