Solving order constraints in logarithmic space.

We combine methods of order theory, finite model theory, and universal algebra to study, within the constraint satisfaction framework, the complexity of some well-known combinatorial problems connected with a finite poset. We identify some conditions on a poset which guarantee solvability of the problems in (deterministic, symmetric, or non-deterministic) logarithmic space. On the example of order constraints we study how a certain algebraic invariance property is related to solvability of a constraint satisfaction problem in non-deterministic logarithmic space

'Heaven starts at your parents' feet' : adolescent bowing to parents and associated spiritual attitudes

In a quantitative survey of religious attitudes and practices in a multi-religious sample of 369 school pupils aged between 13 and 15 in London, the practice of bowing to parents was found widespread in 22% of adolescents spanning several religious affiliations and ethnicities – especially Buddhists, Hindus and those of Indian, African and ‘Other Asian’ ethnicity. Whether an adolescent bowed correlated significantly with spiritual attitudes such as wanting to abstain from alcohol, hearing religious stories, being inspired by religious festivals and liking the idea of seeing God in everything. Findings suggest bowing to parents can have religious significance on all three levels of Jackson’s Interpretive Approach and therefore cannot be regarded as a ‘cultural accretion’ of religion. Study of bowing to parents could form a unifying exercise in shared values for study of religion in the plural classroom and facilitate community cohesion in certain religious membership groups

Magnetization reversal in melt-quenched NdFeB

Melt-quenched NdFeB is an important modern permanent magnet material. However there still remains doubt as to the magnetization reversal mechanism which controls coercivity in material prepared by this processing route. To investigate this problem a new technique based on measurements of reversible magnetization along recoil curves has been used. The technique identifies the presence of free domain walls during magnetic reversal. For this study samples of isotropic (MQI), hot pressed (MQII) and die upset (MQIII) melt-quenched NdFeB were examined. The results indicate that in MQI free domain walls are not present during reversal and the reversal mechanism is most likely incoherent rotation of some form. Free domain walls are also not present during reversal in the majority of grains of MQII, even though initial magnetization measurements indicate that the grain size is large enough to support them. In MQIII free domain walls are present during reversal. These results are attributed to the reduced domain wall nucleation field in MQIII compared with MQII and the increased dipolar interactions in MQIII

Axonal Preservation in Deep Subcortical White Matter Lesions in the Ageing Brain

Cerebral white matters lesions (WML) are seen in 94% of the population aged 64 and over and are associated with cognitive decline and depression. We used immunohistochemistry and stereological methods on post mortem brain samples derived from the Medical Research Council Cognitive Function and Ageing Study (MRC-CFAS) cohort to investigate the axonal density within deep subcortical lesions. There was no significant difference between the lesional and control white matter, therefore, we conclude that there is axonal preservation within these lesions that are characterized by demyelination

Long distance regularization in chiral perturbation theory with decuplet

We investigate the use of long distance regularization in SU(3) baryon chiral perturbation theory with decuplet fields. The one-loop decuplet contributions to the octet baryon masses, axial couplings, S-wave nonleptonic hyperon decays and magnetic moments are evaluated in a chirally consistent fashion by employing a cutoff to implement long distance regularization. The convergence of the chiral expansions of these quantities is improved compared to the dimensionally regularized version which indicates that the propagation of Goldstone bosons over distances smaller than a typical hadronic size, which is beyond the regime of chiral perturbation theory but included by dimensional regularization, is removed by use of a cutoff.Comment: 31 page

Phenological growth stages of tree tomato (Solanum betaceum Cav.), an emerging fruit crop, according to the basic and extended BBCH scale

[EN] The tree tomato (Solanum betaceum Cav.) is a small tree native to the Andean region cultivated for its juicy fruits, which are having an increasing demand. Tree tomato is morphologically and phenologically different from other Solanum crops and tools for the phenological description of the developmental stages are needed for the enhancement of this emerging crop. We developed a basic and an extended numerical BBCH (Biologische Bundesanstalt, Bundessortenamnt, Chemische Industrie) scales which allow the precise identification of the phenological stages of tree tomato. Eight principal stages are described for germination, leaf development, formation of side shoots, stem elongation, inflorescence emergence, flowering, development of fruit, and ripening of fruit and seed. The basic (two-digit) scale is sufficiently precise for germination, stem elongation, and ripening of fruit and seed. However, for leaf development, formation of side shoots, inflorescence emergence, flowering, and development of fruit the extended (three-digit) scale is considered necessary for an adequate description. The description of the phenological stages is combined with illustrations for clarification. The tree tomato BBCH scale has been validated by characterizing 24 accessions of different varietal groups for traits of agronomic interest and evaluating the differences observed among accessions at specific BBCH developmental stages. The basic and extended BBCH scales represent a useful tool for the description and identification of phenological scales of tree tomato. These scales will be useful for the enhancement of this emerging fruit crop. (C) 2015 Elsevier B.V. All rights reserved.Acosta-Quezada, P.; Riofrío-Cuenca, T.; Rojas, J.; Vilanova Navarro, S.; Plazas Ávila, MDLO.; Prohens Tomás, J. (2016). Phenological growth stages of tree tomato (Solanum betaceum Cav.), an emerging fruit crop, according to the basic and extended BBCH scale. Scientia Horticulturae. 199:216-223. doi:10.1016/j.scienta.2015.12.045S21622319

Theta-point behavior of diluted polymer solutions: Can one observe the universal logarithmic corrections predicted by field theory?

In recent large scale Monte-Carlo simulations of various models of Theta-point polymers in three dimensions Grassberger and Hegger found logarithmic corrections to mean field theory with amplitudes much larger than the universal amplitudes of the leading logarithmic corrections calculated by Duplantier in the framework of tricritical O(n) field theory. To resolve this issue we calculate the universal subleading correction of field theory, which turns out to be of the same order of magnitude as the leading correction for all chain lengths available in present days simulations. Borel resummation of the renormalization group flow equations also shows the presence of such large corrections. This suggests that the published simulations did not reach the asymptotic regime. To further support this view, we present results of Monte-Carlo simulations on a Domb-Joyce like model of weakly interacting random walks. Again the results cannot be explained by keeping only the leading corrections, but are in fair accord with our full theoretical result. The corrections found for the Domb-Joyce model are much smaller than those for other models, which clearly shows that the effective corrections are not yet in the asymptotic regime. All together our findings show that the existing simulations of Theta-polymers are compatible with tricritical field theory since the crossover to the asymptotic regime is very slow. Similar results were found earlier for self avoiding walks at their upper critical dimension d=4.Comment: 15 pages,6 figure

Controlling gold nanoparticle assembly on electron beam-reduced nitrophenyl self-assembled monolayers <i>via</i> electron dose

Electron beam lithography is a well-established tool suitable for the modification of substrate surface chemistry. It therefore follows that the deposition and self-assembly of nanoparticles on a surface can be directed using this method. This work explores the effect of electron dose on the electron beam lithographic patterning of self-assembled monolayers (SAMs) on gold surfaces. Electron beam irradiation of the sample induces conversion of the SAM terminal functional aromatic nitro (NO2) moieties to aromatic amino (NH2) moieties. The cationic NH2 functionalised regions direct the site-specific assembly of anionic citrate-passivated gold nanoparticles in aqueous solution at pH 4.5. Control of nanoparticle attachment to the SAM is demonstrated over the exposure range 5000–125,000 uC/cm2. Overexposure led to significant numbers of secondary electrons reaching the surface, causing conversion of functional aromatic moieties outside of the regions irradiated, which reduced feature quality and regional selectivity of adsorption

Review of two-photon exchange in electron scattering

We review the role of two-photon exchange (TPE) in electron-hadron scattering, focusing in particular on hadronic frameworks suitable for describing the low and moderate Q^2 region relevant to most experimental studies. We discuss the effects of TPE on the extraction of nucleon form factors and their role in the resolution of the proton electric to magnetic form factor ratio puzzle. The implications of TPE on various other observables, including neutron form factors, electroproduction of resonances and pions, and nuclear form factors, are summarized. Measurements seeking to directly identify TPE effects, such as through the angular dependence of polarization measurements, nonlinear epsilon contributions to the cross sections, and via e+ p to e- p cross section ratios, are also outlined. In the weak sector, we describe the role of TPE and gamma-Z interference in parity-violating electron scattering, and assess their impact on the extraction of the strange form factors of the nucleon and the weak charge of the proton.Comment: 73 pages, 40 figures, review article for Prog. Part. Nucl. Phys. (dedicated to the memory of John A. Tjon