CM points and weight 3=2 modular forms

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Charge ordering and antiferromagnetic exchange in layered molecular crystals of the theta type

We consider the electronic properties of layered molecular crystals of the type theta -D(2)A where A is an anion and D is a donor molecule such as bis-(ethylenedithia-tetrathiafulvalene) (BEDT-TTF), which is arranged in the theta -type pattern within the layers. We argue that the simplest strongly correlated electron model that can describe the rich phase diagram of these materials is the extended Hubbard model on the square lattice at one-quarter filling. In the limit where the Coulomb repulsion on a single site is large, the nearest-neighbor Coulomb repulsion V plays a crucial role. When V is much larger than the intermolecular hopping integral t the ground state is an insulator with charge ordering. In this phase antiferromagnetism arises due to a novel fourth-order superexchange process around a plaquette on the square lattice. We argue that the charge ordered phase is destroyed below a critical nonzero value V, of the order of t. Slave-boson theory is used to explicitly demonstrate this for the SU(N) generalization of the model, in the large-N limit. We also discuss the relevance of the model to the all-organic family beta-(BEDT-TTF)(2)SF5YSO3 where Y=CH2CF2, CH2, CHF.

Stereochemistry of cyclopentane derivatives from (2,3)J(CH) dependence on dihedral angle (theta H-C-C-X)

The (2,3)J(CH) dependence on dihedral angle (theta H-C-C-X) for cyclopentane derivatives was investigated. We observed that the combined use of experimentally obtained (2,3)J(CH) values and the theoretically determined dihedral angles between the corresponding nuclei can be used to infer the relative stereochemistry of the ring substituents in cyclopentane derivatives. There is a good correlation between the magnitude of (3)J(CH) and the dihedral angle between the hydrogen and the coupled carbon (R-2 = 0.88). Copyright (C) 2008 John Wiley & Sons, Ltd.

Relativizing Minimality for A-movement: phi- and theta-relations

This paper discusses two arguments raised against Hornstein`s (1999, 2001) Movement Theory of Control (MTC): Landau`s (2003) contrast between raising and passivized subject control predicates and Culicover and Jackendoff`s (2001) contrast between control and raising within nominals. I show that rather than counter-arguments, the data they present can actually be analyzed as arguments in favor of the MTC. More specifically, I argue that the puzzling contrasts discussed by these authors can be adequately accounted for within the MTC if minimality computations regarding A-movement are relativized in terms of phi- or theta-relations.

Baseline hippocampal theta oscillation speeds correlate with rate of operant task acquisition

Many lines of evidence indicate that theta rhythm, a prominent neural oscillatory mode found in the mammalian hippocampus, plays a key role in the acquisition, processing, and retrieval of memories. However, a predictive neurophysiological feature of the baseline theta rhythm that correlates with the learning rate across different animals has yet to be identified. Here we show that the mean theta rhythm speed observed during baseline periods of immobility has a strong positive correlation with the rate at which rats learn an operant task. This relationship is observed across rats, during both quiet waking (r=0.82; p<0.01) and paradoxical sleep (r=0.83; p<0.01), suggesting that the basal theta frequency relates to basic neurological processes that are important in the acquisition of operant behavior. (c) 2008 Elsevier B.V. All rights reserved.

Effects of bromazepam in frontal theta activity on the performance of a sensorimotor integration task: A quantitative electroencephalography study

Our objective is to verify the modulatory effects of bromazepam on EEG theta absolute power when subjects were submitted to a visuomotor task (i.e., car driver task). Sample was composed of 14 students (9 males and 5 females), right handed, with ages varying between 23 and 42 years (mean = 32.5 +/- 9.5), absence of mental or physical impairments, no psychoactive or psychotropic substance use and no neuromuscular disorders (screened by a clinical examination). The results showed an interaction between condition and electrodes (p=0.034) in favor of F8 electrode compared with F7 in both experimental conditions (t-test; p=0.001). Additionally, main effects were observed for condition (p=0.001), period (p=0.001) and electrodes (p=0.031) in favor of F4 electrode compared with F3. In conclusion, Br 6 mg of bromazepam may interfere in sensorimotor processes in the task performance in an unpredictable scenario allowing that certain visuospatial factors were predominant. Therefore, the results may reflect that bromazepam effects influence the performance of the involved areas because of the acquisition and integration of sensory stimuli processes until the development of a motor behavior based on the same stimuli. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Decompositions of complete graphs into theta graphs with fewer than ten edges

A theta graph is a graph consisting of three pairwise internally disjoint paths with common end points. Methods for decomposing the complete graph K-nu into theta graphs with fewer than ten edges are given.

Stress affects theta activity in limbic networks and impairs novelty-induced exploration and familiarization

Exposure to a novel environment triggers the response of several brain areas that regulate emotional behaviors. Here, we studied theta oscillations within the hippocampus (HPC)-amygdala (AMY)-medial prefrontal cortex (mPFC) network in exploration of a novel environment and subsequent familiarization through repeated exposures to that same environment; in addition, we assessed how concomitant stress exposure could disrupt this activity and impair both behavioral processes. Local field potentials were simultaneously recorded from dorsal and ventral hippocampus (dHPC and vHPC respectively), basolateral amygdala (BLA) and mPFC in freely behaving rats while they were exposed to a novel environment, then repeatedly re-exposed over the course of 3 weeks to that same environment and, finally, on re-exposure to a novel unfamiliar environment. A longitudinal analysis of theta activity within this circuit revealed a reduction of vHPC and BLA theta power and vHPC-BLA theta coherence through familiarization which was correlated with a return to normal exploratory behavior in control rats. In contrast, a persistent over-activation of the same brain regions was observed in stressed rats that displayed impairments in novel exploration and familiarization processes. Importantly, we show that stress also affected intra-hippocampal synchrony and heightened the coherence between vHPC and BLA. In summary, we demonstrate that modulatory theta activity in the aforementioned circuit, namely in the vHPC and BLA, is correlated with the expression of anxiety in novelty-induced exploration and familiarization in both normal and pathological conditions.

Spontaneous leptonic CP violation and nonzero theta(13)

We consider a simple extension of the Standard Model by adding two Higgs triplets and a complex scalar singlet to its particle content. In this framework, the CP symmetry is spontaneously broken at high energies by the complex vacuum expectation value of the scalar singlet. Such a breaking leads to leptonic CP violation at low energies. The model also exhibits an A(4) X Z(4) flavor symmetry which, after being spontaneously broken at a high-energy scale, yields a tribimaximal pattern in the lepton sector. We consider small perturbations around the tribimaximal vacuum alignment condition in order to generate nonzero values of theta(13), as required by the latest neutrino oscillation data. It is shown that the value of theta(13) recently measured by the Daya Bay Reactor Neutrino Experiment can be accommodated in our framework together with large Dirac-type CP violation. We also address the viability of leptogenesis in our model through the out-of-equilibrium decays of the Higgs triplets. In particular, the CP asymmetries in the triplet decays into two leptons are computed and it is shown that the effective leptogenesis and low-energy CP-violating phases are directly linked.

Regulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-[kappa]B) by protein Kinase C theta (PKC-[theta]) and cylindromatosis (CYLD) in murine listeriosis and toxoplasmosis

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2013

Inversió cega de funcions no-lineals mitjançant un procés de Gaussianització

En aquest treball es presenta un nou mètode per a la inversió cega de funcions no-lineals mitjançant la gaussianització del senyal observat. El mètode es basa en restituir el caràcter aproximadament gaussià que presenta un senyal filtrat, gràcies al teorema del límit central,que ha vist canviada la seva distribució per l’efecte d’una funció no-lineal. Inicialment, doncs,aquest mètode és útil per a la inversió de sistemes de Wiener, tot i que en els darrers experiments realitzats s’han obtingut resultats interessants en sistemes purament no-lineals. El treball presenta dues possibles parametritzacions, la primera basada en xarxes neurals i la segona en polinomis. En els dos casos s’aconsegueix invertir la funció desconeguda sense tenir cap coneixement a priori ni del senyal original, ni del filtre, ni de la funció no-lineal que volem invertir.

L'impacte dels recursos electrònics en el desenvolupament de la col·lecció, les funcions dels bibliotecaris i els consorcis de biblioteques

A mesura que els bibliotecaris anaven integrant documents audiovisuals a les seves col·leccions i més endavant documents electrònics, van passar de fer la selecció com una activitat individual a fer-la com una activitat en grup. Els bibliotecaris feien esforços per mantenir-se en el centre del procés de selecció resultant i incorporar-lo a l'organització de la biblioteca. No obstant, amb l'arribada d'Internet i la capacitat de compartir simultàniament recursos virtuals, el desenvolupament cooperatiu de la col·lecció mitjançant acords consorciats es va generalitzar un cop més. La capacitat dels consorcis de comprar productes a un preu millor que les biblioteques individualment els ha pogut fet molt populars entre els agents finançadors. Tanmateix, com a resultat d'això ha minvat el paper del bibliotecari responsable de la selecció ("selector"). A mesura que s'accelera la compra de recursos virtuals, especialment a través dels acords consorciats, desapareixerà gradualment l'autonomia de la biblioteca local i les funcions dels bibliotecaris canviaran de manera dràstica. Aquesta ràpida transformació s'il·lustra amb un debat d'OhioLINK i els seus efectes, tant positius com negatius, en una de les biblioteques membres del consorci.

Noves funcions en un entorn de canvis: implicacions de l'accés obert per a les biblioteques

Aquest article examina les possibles implicacions de l'accés obert en la gestió de les biblioteques. Aquesta examinació té lloc en un context en què s'assumeix que el model tradicional d'edició i l'accés obert coexisteixen. L'accés obert presenta nombrosos reptes i oportunitats, però les biblioteques emprenedores trobaran noves formes per servir els usuaris en un nou entorn en el que es combina l'accés obert amb el tradicional (MOA). Per tal de portar-ho a terme, caldrà que aquestes biblioteques redissenyin la seva organització, i això podrà suposar una pressió sobre els recursos econòmics i de personal.

The immunological synapse and actin assembly: a regulatory role for PKC theta.

Engagement of the T cell receptor leads to the accumulation of filamentous actin, which is necessary for the formation of the immunological synapse and subsequent T cell activation. In the December issue of Molecular Cell, Sasahara et al. provide new insights into the link between the T cell receptor and actin assembly in the immunological synapse, and reveal a critical regulatory role for PKC theta in this process.