Identification of a set of genes showing regionally enriched expression in the mouse brain

Background

We have recorded responses from single neurons in murine visual cortex to determine the effectiveness of the input from the two murine cone photoreceptor mechanisms and whether there is any unique selectivity for cone inputs at this higher region of the visual system that would support the possibility of colour vision in mice. Each eye was stimulated by diffuse light, either 370 (strong stimulus for the ultra-violet (UV) cone opsin) or 505 nm (exclusively stimulating the middle wavelength sensitive (M) cone opsin), obtained from light emitting diodes (LEDs) in the presence of a strong adapting light that suppressed the responses of rods.

Results

Single cells responded to these diffuse stimuli in all areas of striate cortex. Two types of responsive cells were encountered. One type (135/323 – 42%) had little to no spontaneous activity and responded at either the on and/or the off phase of the light stimulus with a few impulses often of relatively large amplitude. A second type (166/323 – 51%) had spontaneous activity and responded tonically to light stimuli with impulses often of small amplitude. Most of the cells responded similarly to both spectral stimuli. A few (18/323 – 6%) responded strongly or exclusively to one or the other spectral stimulus and rarely in a spectrally opponent manner.

Conclusion

Most cells in murine striate cortex receive excitatory inputs from both UV- and M-cones. A small fraction shows either strong selectivity for one or the other cone mechanism and occasionally cone opponent responses. Cells that could underlie chromatic contrast detection are present but extremely rare in murine striate cortex.     

Theoretical radiative properties between states of the triplet manifold of NH radical

Ab initio transition dipole moments between states of the triplet manifold of NH radical are determined at the complete active space self-consistent field, followed by the internally contracted multireference singles plus doubles configuration interaction level of theory with a modified aug-cc-pVTZ basis set that accounts for valence-Rydberg interactions. This enables the computation of various radiative characteristics such as Einstein coefficients, radiative lifetimes, and oscillator strengths. These properties concern as well valence and Rydberg states. For the valence states, only the (0, 0) band of the A 3 Pi-X 3 Sigma(-) transition has received some important amount of attention. Data for the other transitions are rather scarce and sometimes inexistent. The results obtained in this work show good agreement with the available experimental data in comparison to other theoretical numbers reported in the literature.     

Effect of substrate temperature on electrical and magnetic properties of epitaxial La1−x Pb x MnO3 films

Epitaxial La_1−x Pb _x MnO₃ (LPMO) thin films, grown on (100) SrTiO₃ substrates by laser ablation technique at different temperatures between 600 and 850°C, have been characterized for electrical and magnetic properties. The temperature dependence of resistivity showed that the metal-insulator transition temperature (T _MI) decreases with increasing substrate temperature, which has been attributed to decrease in Pb content in the filsm. The YBa₂Cu₃O _x /La_1−x MnO₃ heterostructures, exhibiting both superconductivity and ferromagnetism, have been fabricated.     

A Criterion for Finite Topological Determinacy of Map-Germs

Let f, g: (Rⁿ, 0) (R^p, 0) be two C map-germs. Then f and gare C⁰-equivalent if there exist homeomorphism-germs h and lof (Rⁿ, 0) and (R^p, 0) respectively such that g = l f h^–1.Let k be a positive integer. A germ f is k-C⁰-determined ifevery germ g with j^k g(0) = j^k f(0) is C⁰-equivalent to f. Moreover,we say that f is finitely topologically determined if f is k-C⁰-determinedfor some finite k. We prove a theorem giving a sufficient conditionfor a germ to be finitely topologically determined. We explainthis condition below. Let N and P be two C manifolds. Consider the jet bundle J^k(N,P) with fiber J^k(n, p). Let z in J^k(n, p) and let f be suchthat z = j^kf(0). Define Whether (f) < k depends only on z, not on f. We can thereforedefine the set Let W^k(N, P) be the subbundle of J^k(N, P) with fiber W^k(n, p).Mather has constructed a finite Whitney (b)-regular stratificationS^k(n, p) of J^k(n, p) – W^k(n, p) such that all strata aresemialgebraic and K-invariant, having the property that if S^k(N,P) denotes the corresponding stratification of J^k(N, P) –W^k(N, P) and f C(N, P) is a C map such that j^kf is multitransverseto S^k(N, P), j^kf(N) W^k(N, P) = and N is compact (or f is proper),then f is topologically stable. For a map-germ f: (Rⁿ, 0) (R^p, 0), we define a certain ojasiewiczinequality. The inequality implies that there exists a representativef: U R^p such that j^kf(U – 0) W^k (Rⁿ, R^p = and suchthat j^kf is multitransverse to S^k (Rⁿ, R^p) at any finite setof points S U – 0. Moreover, the inequality controlsthe rate j^kf becomes non-transverse as we approach 0. We showthat if f satisfies this inequality, then f is finitely topologicallydetermined. 1991 Mathematics Subject Classification: 58C27.     

State to state rotational integral cross sections and rate coefficients of HCP collision with He at low temperature

We report coupled-cluster [CCSD(T)] ab initio calculations of the two-dimensional interaction potential energy surface of the HCP–He complex. The aug-cc-pVTZ and aug-cc-pVQZ gaussian basis sets are used. HCP is held fixed at its linear equilibrium ground vibrational level with the corresponding [H–C] and [C–P] bond lengths set to the values 2.016 bohrs and 2.914 bohrs, respectively. Our calculations are corrected for basis set superposition errors (BSSE). The PES obtained with the above triple zeta basis set has two minima located 22.018 cm⁻¹ and 14.808 cm⁻¹ below the HCP+He dissociation limit. These well depths are shifted to 23.505 cm⁻¹ and 15.949 cm⁻¹, respectively, when the quadruple zeta basis set is used. Our PESs are fitted on a basis of Legendre polynomial functions and state to state rotational integral cross sections of the HCP collision with He are calculated in the close-coupling (CC) approximation. Downward rate coefficients are inferred at low temperature () by averaging the cross sections over a Maxwell–Boltzmann velocity distribution. An analysis of our results shows that for kinetic energies greater than 60 cm⁻¹, the 0→2 transition dominates. The numbers derived here may be very useful for astrophysical observations.     

Preparation and characterization of MgB2 superconductor

The MgB₂ superconductor, synthesized using solid-state and liquid-phase sintering methods, have been characterized for various properties. The upper critical field, irreversibility line and critical current density have been determined using magnetization data. The current-voltage characteristics recorded under an applied magnetic field revealed the existence of vortex glass transition. The surface analysis using X-ray photoelectron spectroscopy shows that MgB₂ is sensitive to atmospheric degradation.