On polymorphic logical gates in sub-excitable chemical medium

In a sub-excitable light-sensitive Belousov-Zhabotinsky chemical medium an asymmetric disturbance causes the formation of localized traveling wave-fragments. Under the right conditions these wave-fragment can conserve their shape and velocity vectors for extended time periods. The size and life span of a fragment depend on the illumination level of the medium. When two or more wave-fragments collide they annihilate or merge into a new wave-fragment. In computer simulations based on the Oregonator model we demonstrate that the outcomes of inter-fragment collisions can be controlled by varying the illumination level applied to the medium. We interpret these wave-fragments as values of Boolean variables and design collision-based polymorphic logical gates. The gate implements operation XNOR for low illumination, and it acts as NOR gate for high illumination. As a NOR gate is a universal gate then we are able to demonstrate that a simulated light sensitive BZ medium exhibits computational universality

Geometric Phases generated by the non-trivial spatial topology of static vector fields coupled to a neutral spin-endowed particle. Application to 171Yb atoms trapped in a 2D optical lattice

We have constructed the geometric phases emerging from the non-trivial topology of a space-dependent magnetic field, interacting with the spin magnetic moment of a neutral particle. Our basic tool is the local unitary transformation which recasts the magnetic spin interaction under a diagonal form. Rewriting the kinetic term in the "rotated" frame requires the introduction of non-Abelian covariant derivatives, involving the gradients of the Euler angles which define the orientation of the local field. Within the rotated frame, we have built a perturbation scheme,assuming that the longitudinal non-Abelian field component dominates the transverse ones, to be evaluated to second-order. The geometry embedded in the longitudinal gauge vector field and its curl, the geometric magnetic field, is described by the associated Aharonov-Bohm phase. As an illustration, we study the physics of cold 171Yb atoms dressed by two sets of circularly polarized beams, forming square or triangular 2D optical lattices. The geometric field is computed explicitly from the Euler angles. The magnitude of 2nd-order corrections due to transverse fields can be reduced to the percent level by a choice of light intensity which keeps the dressed atom loss rate below 5 s^{-1}. An auxiliary optical lattice confines the atoms within 2D domains where the geometric field is pointing upward.Comment: 12 pages, 4 figures. Comments and one figure added about the effect of the additional scalar potential (sec. V.B). To be published in J. Phys. A:Math. Theo

Analysis of region-specific changes in gene expression upon treatment with citalopram and desipramine reveals temporal dynamics in response to antidepressant drugs at the transcriptome level

RATIONALE: The notion that the onset of action of antidepressant drugs (ADs) takes weeks is widely accepted; however, the sequence of events necessary for therapeutic effects still remains obscure. OBJECTIVE: We aimed to evaluate a time-course of ADs-induced alterations in the expression of 95 selected genes in 4 regions of the rat brain: the prefrontal and cingulate cortices, the dentate gyrus of the hippocampus, and the amygdala. METHODS: We employed RT-PCR array to evaluate changes during a time-course (1, 3, 7, 14, and 21 days) of treatments with desipramine (DMI) and citalopram (CIT). In addition to repeated treatment, we also conducted acute treatment (a single dose of drug followed by the same time intervals as the repeated doses). RESULTS: Time-dependent and structure-specific changes in gene expression patterns allowed us to identify spatiotemporal differences in the molecular action of two ADs. Singular value decomposition analysis revealed differences in the global gene expression profiles between treatment types. The numbers of characteristic modes were generally smaller after CIT treatment than after DMI treatment. Analysis of the dynamics of gene expression revealed that the most significant changes concerned immediate early genes, whose expression was also visualized by in situ hybridization. Transcription factor binding site analysis revealed an over-representation of serum response factor binding sites in the promoters of genes that changed upon treatment with both ADs. CONCLUSIONS: The observed gene expression patterns were highly dynamic, with oscillations and peaks at various time points of treatment. Our study also revealed novel potential targets of antidepressant action, i.e., Dbp and Id1 genes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00213-012-2714-0) contains supplementary material, which is available to authorized users

Preliminary petrological and palinological characteristics of coal clasts from the Menilite Formation of the Silesian Unit

Coal-bearing conglomerates occur in the Menilite Formation of the Silesian Unit, outcropped in the village of Kobielnik. Coal particles are angular and differ in size (2 mm-6 cm). The examined coal shows rather predominance of vitrinite (collotelinite, collodetrinite, vitrodetrinite). However, the presence of inertinite (fusinite, semifusinite and inertodetrinite with rather accessory funginite and secretinite) is also significant. However, liptinite (sporinite, cutinite and resinite) also indicates its presence in the maceral composition. The results of both coal petrographic and palynologcal analyses were conducted with the intention of applying them to reconstruct environments of coalformation. Palynological studies revealed palynofacies consisting mainly of black palynoclasts ofrectangle or oval shape. Miospores are abundant and various in colour-from yellow to dark brown. The miospore assemblage is dominated by Lycospora and several other Carboniferous genera occur there. The presence of Radiizonates aligerens (Knox) Staplin, Jansonius, the guide species to the lower part of the Westphalian A (Langsettian) indicate that at least part of the coal pieces come from this part of the Pennsylvanian. The age position of the whole miospore assemblage should be determined as the Late Bashkirian-Moscovian (Westphalian). Additionaly, some older miospores, usually dark in colour, were found in this assemblage and they are considered as reworked

Pulmonary haemodynamics in patients with OSAS or an overlap syndrome

Background. Alveolar hypoxia is the most important mechanism leading to pulmonary arterial vasoconstriction, remodelling and pulmonary hypertension. Patients with Obstructive Sleep Apnoea Syndrome (OSAS) experience multiple short periods of alveolar hypoxia during apnoeic episodes. However, the question as to whether these hypoxic episodes are responsible for the development of permanent pulmonary hypertension is still debatable. We aimed to investigate the relationship between the episodes of nocturnal desaturation and pulmonary haemodynamics in two distinct group patients: with pure OSAS or an overlap syndrome. Methods: We studied 67 patients with severe OSAS (means: age 45±8 years, AHI 62±22, FEV1 3.6±0.8 L = 97±16% of predicted PaO2 72±10 mmHg, PaCO2 40±4 mmHg) and 17 patients with an overlap syndrome (OS), means: age 51±5 years, AHI 64±19, FEV1 1.5±0.7 = 43±16% of predicted PaO2 57±9 mmHg). All subjects underwent pulmonary artery catheterisation with pressure and flow recordings and an overnight full sleep study. Results. On average patients with OSAS had nocturnal desaturation (mean overnight SaO2 = 87±5%) and normal PPA (15.8±4.6 mmHg). Only 11 out of 67 subjects (16%) presented with pulmonary hypertension. Patients with OS had nocturnal desaturation (mean overnight SaO2 = 80.2±8.5%) and mild pulmonary hypertension (PPA 24.2±7.4 mmHg). Only three out of 17 patients had normal pulmonary arterial pressure. Conclusions. In patients with severe OSAS, pulmonary hypertension is rare (16%) and is related best to the severity of the disease and to obesity. In OS patients diurnal pulmonary hypertension is frequent but does not correlate with the severity of nocturnal desaturation

Optical Flux Lattices for Two-Photon Dressed States

We describe a simple scheme by which "optical flux lattices" can be implemented in ultracold atomic gases using two-photon dressed states. This scheme can be applied, for example, to the ground state hyperfine levels of commonly used atomic species. The resulting flux lattices simulate a magnetic field with high mean flux density, and have low energy bands analogous to the lowest Landau level. We show that in practical cases the atomic motion significantly deviates from the adiabatic following of one dressed state, and that this can lead to significant interactions even for fermions occupying a single band. Our scheme allows experiments on cold atomic gases to explore strong correlation phenomena related to the fractional quantum Hall effect, both for fermions and bosons.Comment: 6 page

Chronic mild stress alters the somatostatin receptors in the rat brain

RATIONALE: The involvement of somatostatin (SST) and its receptors in the pathophysiology of depression and stress has been evidenced by numerous studies. OBJECTIVES: The purpose of the present study was to find whether chronic mild stress (CMS), an animal model of depression, affects the SST receptors in the rat brain and pituitary, as well as the level of SST in plasma. METHODS: In CMS model, rats were subjected to 2 weeks of stress and behaviorally characterized using the sucrose consumption test into differently reacting groups based on their response to stress, i.e., stress-reactive (anhedonic), stress-non-reactive (resilient), and invert-reactive rats (characterized by excessive sucrose intake). We measured specific binding of [(125)I]Tyr(3)-Octreotide, expression of mRNA encoding sst2R receptors in the rat brains, expression of SST and its receptors in rat pituitary, and the level of SST in the plasma. RESULTS: The obtained results show decreases in binding of [(125)I]Tyr(3)-Octreotide in most of rat brain regions upon CMS and no significant differences between three stressed groups of animals, except for significant up-regulation of sst2 receptor in medial habenula (MHb) in the stress-reactive group. In the same group of animals, significant increase in plasma SST level was observed. CONCLUSIONS: There are two particularly sensitive sites distinguishing the response to stress in CMS model. In the brain, it is MHb, while on the periphery this predictor is SST level in plasma. These changes may broaden an understanding of the mechanisms involved in the stress response and point to the intriguing role of MHb

Constraints on a second planet in the WASP-3 system

There have been previous hints that the transiting planet WASP-3 b is accompanied by a second planet in a nearby orbit, based on small deviations from strict periodicity of the observed transits. Here we present 17 precise radial velocity measurements and 32 transit light curves that were acquired between 2009 and 2011. These data were used to refine the parameters of the host star and transiting planet. This has resulted in reduced uncertainties for the radii and masses of the star and planet. The radial-velocity data and the transit times show no evidence for an additional planet in the system. Therefore, we have determined the upper limit on the mass of any hypothetical second planet, as a function of its orbital period.Comment: Accepted for publication in The Astronomical Journa

Structural basis of transposon end recognition explains central features of Tn7 transposition systems

Tn7 is a bacterial transposon with relatives containing element-encoded CRISPR-Cas systems mediating RNA-guided transposon insertion. Here, we present the 2.7 Å cryoelectron microscopy structure of prototypic Tn7 transposase TnsB interacting with the transposon end DNA. When TnsB interacts across repeating binding sites, it adopts a beads-on-a-string architecture, where the DNA-binding and catalytic domains are arranged in a tiled and intertwined fashion. The DNA-binding domains form few base-specific contacts leading to a binding preference that requires multiple weakly conserved sites at the appropriate spacing to achieve DNA sequence specificity. TnsB binding imparts differences in the global structure of the protein-bound DNA ends dictated by the spacing or overlap of binding sites explaining functional differences in the left and right ends of the element. We propose a model of the strand-transfer complex in which the terminal TnsB molecule is rearranged so that its catalytic domain is in a position conducive to transposition