Stochastic equations for a self-regulating gene

Expression of cellular genes is regulated by binding of transcription factors to their promoter, either activating or inhibiting transcription of a gene. Particularly interesting is the case when the expressed protein regulates its own transcription. In this paper the features of this self-regulating process are investigated. In the here presented model the gene can be in two states. Either a protein is bound to its promoter or not. The steady state distributions of protein during and at the end of both states are analyzed. Moreover a powerful numerical method based on the corresponding master equation to compute the protein distribution in the steady state is presented and compared to an already existing method. Additionally the special case of self-regulation, in which protein can only be produced, if one of these proteins is bound to the promoter region, is analyzed. Furthermore a self-regulating gene is compared to a similar gene, which also has two states and produces the same amount of proteins but is not regulated by its protein-product

A large energy-gap oxide topological insulator based on the superconductor BaBiO3

Mixed-valent perovskite oxides based on BaBiO3 (BBO) are, like cuperates, well-known high-Tc superconductors. Recent ab inito calculations have assigned the high-Tc superconductivity to a correlation-enhanced electron--phonon coupling mechanism, stimulating the prediction and synthesis of new superconductor candidates among mixed-valent thallium perovskites. Existing superconductivity has meant that research has mainly focused on hole-doped compounds, leaving electron-doped compounds relatively unexplored. Here we demonstrate through ab inito calculations that BBO emerges as a topological insulator (TI) in the electron-doped region, where the spin-orbit coupling (SOC) effect is significant. BBO exhibits the largest topological energy gap of 0.7 eV among currently known TI materials, inside which Dirac-type topological surface states (TSSs) exit. As the first oxide TI, BBO is naturally stable against surface oxidization and degrading, different from chalcoginide TIs. An extra advantage of BBO lies in its ability to serve an interface between the TSSs and the superconductor for the realization of Majorana Fermions

Zum Tieftemperaturverhalten von Na3NO3

Low temperature Guinier photographs of Na3NO3 ( + 20° → - 140 °C) indicate two phase transitions to M-Na3NO3 and T-Na3NO3 at - 53±3°C and - 122±3°C, respectively. During the phase transitions the main structural features (NO2-[ONa3]: antiperovskite type of structure) remain unchanged. The dynamically disordered NO2- in H-Na3NO3 order to form an antiferroelectric arrangement in T-Na3NO3. Crystal structures for M-Na3NO3 and T-Na3NO3 are proposed

Neue Silber(I)-germanate

Four silver(I)-germanates have been prepared from the binary components Ag2O and GeO2 by solid state reaction applying elevated oxygen pressures (2500-3000 bar). Ag6Ge2O7 isisostructural to Ag6Si2O7(II) [P21,a= 16.268(3), b = 10.021(2), c = 5.320(1) Å, β = 90.85(2)°], Ag10Ge4O13 to Ag10Si4O13 [PT, a = 11.731(3), b = 9.147(3), c = 8.727(4) Å, a = 99.33(2), β = 91.61(1), γ = 114.27(2)°]. According to the results of preparative investigations and chemical analysis there are two further phases in the system Ag2O/GeO2 of compositions ′Ag2GeO3′ and ′Ag2Ge2O5′

Über Rubidiumozonid. Reindarstellung und Kristallstruktur

Es wird ein verbessertes Darstellungsverfahren für Rubidiumozonid mitgeteilt, das über die Ozonisierung des Hyperoxides bei Raumtemperatur und anschließende Anreicherung durch Extraktion mit flüssigem Ammoniak erstmals RbO3 in einkristalliner Form und in präparativen Mengen (1-5 g) zugänglich macht. Die Röntgenstrukturanalyse (P21/c; a = 645,2(3), b = 602,2(3), c = 876,3(3) pm, ß = 122,34(2)°; -20°C; MoK; 2640 Diffraktometerdaten; Rw = 2,6%) sichert die vermutete Konstitution des Anions O3-, das innerhalb der Fehlergrenzen die Punktsymmetrie C2v aufweist mit (OO) = 133,6(9) pm und einem Bindungswinkel von 113,7(7)°. Hinsichtlich der Packung von Kationen und Anionen besteht eine enge Beziehung zur CsCl-Struktur

Anatomy of a Community-Level Fiscal Impact Model: FIT-4-NH.

Abstract: This paper describes the development of a fiscal impact tool for New Hampshire communities (HT -4-NH). FIT -4-NH belongs to a family of computergenerated fiscal impact assessment models designed to estimate the impacts to local government revenues and expenditures that result from economic changes. In the past, work in this area has centered on the completion of countylevel models for the midwestern states. FIT-4-NH is unique in that it was designed for rural community-level use in the northern New England region of the country