Prenatal Inflammation-Induced Hypoferremia Alters Dopamine Function in the Adult Offspring in Rat: Relevance for Schizophrenia

Maternal infection during pregnancy has been associated with increased incidence of schizophrenia in the adult offspring. Mechanistically, this has been partially attributed to neurodevelopmental disruption of the dopamine neurons, as a consequence of exacerbated maternal immunity. In the present study we sought to target hypoferremia, a cytokine-induced reduction of serum non-heme iron, which is common to all types of infections. Adequate iron supply to the fetus is fundamental for the development of the mesencephalic dopamine neurons and disruption of this following maternal infection can affect the offspring's dopamine function. Using a rat model of localized injury induced by turpentine, which triggers the innate immune response and inflammation, we investigated the effects of maternal iron supplementation on the offspring's dopamine function by assessing behavioral responses to acute and repeated administration of the dopamine indirect agonist, amphetamine. In addition we measured protein levels of tyrosine hydroxylase, and tissue levels of dopamine and its metabolites, in ventral tegmental area, susbtantia nigra, nucleus accumbens, dorsal striatum and medial prefrontal cortex. Offspring of turpentine-treated mothers exhibited greater responses to a single amphetamine injection and enhanced behavioral sensitization following repeated exposure to this drug, when compared to control offspring. These behavioral changes were accompanied by increased baseline levels of tyrosine hydroxylase, dopamine and its metabolites, selectively in the nucleus accumbens. Both, the behavioral and neurochemical changes were prevented by maternal iron supplementation. Localized prenatal inflammation induced a deregulation in iron homeostasis, which resulted in fundamental alterations in dopamine function and behavioral alterations in the adult offspring. These changes are characteristic of schizophrenia symptoms in humans

Josephson junction array type I-V characteristics of quench-condensed ultra thin films of Bi

In this communication we report studies of d.c current-voltage (I-V) characteristics of ultra thin films of Bi, quench condensed on single crystal sapphire substrates at T = 15K. The hysteretic I-V characteristics are explained using a resistively and capacitively shunted junction (RCSJ) model of Josephson junction arrays. The Josephson coupling energy($E_J$) and the charging energy($E_c$) are calculated for different thickness($d$) values. A low resistance state is found in the low current regime below the critical current, $I_c$. This resistance $R_0$ is found to have a minimum at a particular thickness ($d_c$) value. Reflection High Energy Electron Diffraction (RHEED) studies are done on these films. A distinct appearance of a diffuse ring near $d_c$ is observed in the diffraction images, consistent with the recent STM studies(Ekinci and Valles, PRL {\bf 82}(1999) 1518). These films show an irreversible annealing when temperature is increased. The annealing temperature ($T_a$) also has a maximum at the same thickness. Althoguh the R$_s$ vs T of quench condensed Bi films suggest that the films are uniform, our results indicate that even in thick films, the order parameter is not fully developed over the complete area of the film. These results are discussed qualitatively.Comment: 6 pages, 6 figure

Magnetic Flux Periodic Response of Nano-perforated Ultrathin Superconducting Films

We have patterned a hexagonal array of nano-scale holes into a series of ultrathin, superconducting Bi/Sb films with transition temperatures 2.65 K $<T_{co} <$5 K. These regular perforations give the films a phase-sensitive periodic response to an applied magnetic field. By measuring this response in their resistive transitions, $R(T)$, we are able to distinguish regimes in which fluctuations of the amplitude, both the amplitude and phase, and the phase of the superconducting order parameter dominate the transport. The portion of $R(T)$ dominated by amplitude fluctuations is larger in lower $T_{co}$ films and thus, grows with proximity to the superconductor to insulator transition.Comment: Revised title, abstract, text, figure

Family -- Dicistroviridae

This chapter focuses on Dicistroviridae family whose two member genera are Cripavirus and Aparavirus. The virions are roughly spherical with a particle diameter of approximately 30 nm and have no envelope. The virions exhibit icosahedral, pseudo T = 3 symmetry and are composed of 60 protomers, each composed of a single molecule of each of VP2, VP3, and VP1. A smaller protein VP4 is also present in the virions of some members and is located on the internal surface of the 5-fold axis below VP1. The virions are stable in acidic conditions and have sedimentation coefficients of between 153 and 167S. They contain a single molecule of infectious, linear, positive sense, single stranded RNA (ssRNA) of approximately 8500–10,000 nt in size with a GC content ranging from 35 to 45%. RNA constitutes about 30% of the virion weight and the proteins account for 70% of the virion weight. The approximately 200 kDa nonstructural polyprotein and 100 kDa structural polyprotein are encoded by ORF 1 and ORF 2, respectively. The virions contain three major structural (capsid) viral proteins, VP1, VP2, and VP3 and the size of these capsid proteins ranges from 24 to 40 kDa. The RNA genome is monopartite and dicistronic with two nonoverlapping ORFs that are separated and flanked by UTRs. All members of the family infect invertebrates and most members of the family are widely distributed in nature. Dicistrovirus infection is not usually associated with overt disease, although infection commonly leads to reduced life expectancy

Efecto del aceite esencial de Lantana camara sobre el crecimiento de Staphylococcus aureus y Escherichia coli

 Se verificó el efecto del aceite esencial de Lantana camara L. sobre el crecimiento de Staphylococcus aureus y Escherichia coli. El aceite se obtuvo por el método hidrodestilación, a partir del de hojas de L. camara, se utilizó concentraciones de 25, 50, 75 y 100% de aceite usando etanol absoluto como diluyente. Para determinar la inhibición de crecimiento antibacteriano se empleó el método de difusión en pozo; añadiendo 25 µl de cada concentración en pozos de 6 mm de diámetro sobre placas petri con Agar Mueller Hinton los cuales fueron sembrados con S. aureus y E. coli por superficie, con concentraciones similares al tubo N° 0.5 del Nefelómetro de Mac Farland (1.5 x 108 UFC/ml); utilizando Vancomicina y Cloranfenicol como controles para S. aureus y E. coli respectivamente. La lectura se realizó a las 24 horas de incubación a 37°C midiendo el halo de inhibición en cada ensayo. Los resultados mostraron que hay mayor inhibición a mayor concentración del aceite esencial (p&lt;0,05), siendo la concentración de 100%, la que logró inhibición máxima con 33 mm para S. aureus. Se concluye que el aceite esencial de L. camara muestra efecto inhibitorio sobre el crecimiento del S. aureus y E. coli. Palabras clave: Aceite esencial, Lantana camara L, crecimiento, Staphylococcus aureus, Escherichia col

Model for initiation of quality factor degradation at high accelerating fields in superconducting radio-frequency cavities

A model for the onset of the reduction in SRF cavity quality factor, the so-called Q-drop, at high accelerating electric fields is presented. Breakdown of the surface barrier against magnetic flux penetration at the cavity equator is considered to be the critical event that determines the onset of Q-drop. The worst case of triangular grooves with low field of first flux penetration Hp, as analyzed previously by Buzdin and Daumens, [1998 Physica C 294: 257], was adapted. This approach incorporates both the geometry of the groove and local contamination via the Ginzburg-Landau parameter kappa, so the proposed model allows new comparisons of one effect in relation to the other. The model predicts equivalent reduction of Hp when either roughness or contamination were varied alone, so smooth but dirty surfaces limit cavity performance about as much as rough but clean surfaces do. When in combination, contamination exacerbates the negative effects of roughness and vice-versa. To test the model with actual data, coupons were prepared by buffered chemical polishing and electropolishing, and stylus profilometry was used to obtain distributions of angles. From these data, curves for surface resistance generated by simple flux flow as a function of magnetic field were generated by integrating over the distribution of angles for reasonable values of kappa. This showed that combined effects of roughness and contamination indeed reduce the Q-drop onset field by ~30%, and that that contamination contributes to Q-drop as much as roughness. The latter point may be overlooked by SRF cavity research, since access to the cavity interior by spectroscopy tools is very difficult, whereas optical images have become commonplace. The model was extended to fit cavity test data, which indicated that reduction of the superconducting gap by contaminants may also play a role in Q-drop.Comment: 15 pages with 7 figure

Bent-core liquid crystals joining the ethylene-oxide/lithium ion tandem: Ionic conductivity and dielectric response towards new electrolytes for energy applications

We report the dielectric and conductivity response of three materials containing bent-core and tetra(ethylene-oxide) moieties, and their complexes doped with lithium triflate salts, as new potential nanostructured electrolytes. Whilst the pristine bent-core compounds do not show mesomorphism, the doped materials display smectic mesophases inside indium tin oxide cells assisted by the selective solvation of the lithium ions in the ethylene-oxide blocks. The dielectric response of the materials in the high-frequency range is controlled by the chemical composition of the bent-core structure, and the presence of lithium ions promotes direct current conductivity at low frequencies, in the σdc ∼ 10-5 S cm−1 range, which can be enhanced to σdc ∼ 10-4 S cm−1 via trans-to-cis photoisomerization of azobenzene groups. The dynamic and dual character of these materials (responding to low and high frequency electrical fields), the formation of ferroelectric crystals capable to store energy, and their interactions with light, will be applied to develop new energy devices

A Phase Glass is a Bose Metal: New Conducting State in 2D

In the quantum rotor model with random exchange interactions having a non-zero mean, three phases, a 1) phase (Bose) glass, 2) superfluid, and 3) Mott insulator, meet at a bi-critical point. We demonstrate that proximity to the bi-critical point and the coupling between the energy landscape and the dissipative degrees of freedom of the phase glass lead to a metallic state at T=0. Consequently, the phase glass is unique in that it represents a concrete example of a metallic state that is mediated by disorder, even in 2D. We propose that the experimentally observed metallic phase which intervenes between the insulator and the superconductor in a wide range of thin films is in actuality a phase glass.Comment: 4 pages, 1 .eps figure, final version to appear in Phys. Rev. Let