Lateralization of alpha oscillations in grapheme-color synaesthetes suggests altered color processing

In grapheme-color synaesthesia, the percept of a particular grapheme causes additional experiences of color. To investigate this interesting integration of modalities, brain activity was recorded of 7 synaesthetes and matched controls using magnetoencephalography. Subjects had to report the color change of one of two letters presented left and right of a fixation cross. One of the letters was neutral (eliciting no color percept), the other one could either be neutral, colored or elicit synaesthesia (in synaesthetes). Additionally, the side of color change was validly or invalidly cued. As expected, in both subject groups 10 Hz alpha oscillations decreased contralateral to the attended side leading to an alpha lateralization. Additionally, controls as well as synaesthetes showed a stronger alpha reduction if the attended letter was colored indicating that color increased the attentional allocation. Interestingly, synaesthetes show the same effect of alpha decrease for synaesthetic color. While color on the attended side reduced alpha power in controls and synaesthetes, color on the unattended side only reduced alpha power in synaesthetes. Indeed, also psychophysical measures indicated changed processing in synaesthetes of unattended color stimuli. Only controls profited from the cue when attending the noncolor stimulus. Synaesthetes, however, performed worse if the noncolor stimulus was validly compared to invalidly cued. This means that synaesthetes performed better on the colored stimulus despite an invalid attentional cue. Changed alpha power lateralization and psychophysics due to unattended colorful input indicate that synaesthetes are more affected by color than controls. This might be due to increased attentional demand

Steinberg modules and Donkin pairs

We prove that in positive characteristic a module with good filtration for a group of type E6 restricts to a module with good filtration for a subgroup of type F4. (Recall that a filtration of a module for a semisimple algebraic group is called good if its layers are dual Weyl modules.) Our result confirms a conjecture of Brundan for one more case. The method relies on the canonical Frobenius splittings of Mathieu. Next we settle the remaining cases, in characteristic not 2, with a computer-aided variation on the old method of Donkin.Comment: 16 pages; proof of Brundan's conjecture adde

Phase Coexistence of a Stockmayer Fluid in an Applied Field

We examine two aspects of Stockmayer fluids which consists of point dipoles that additionally interact via an attractive Lennard-Jones potential. We perform Monte Carlo simulations to examine the effect of an applied field on the liquid-gas phase coexistence and show that a magnetic fluid phase does exist in the absence of an applied field. As part of the search for the magnetic fluid phase, we perform Gibbs ensemble simulations to determine phase coexistence curves at large dipole moments, $\mu$. The critical temperature is found to depend linearly on $\mu^2$ for intermediate values of $\mu$ beyond the initial nonlinear behavior near $\mu=0$ and less than the $\mu$ where no liquid-gas phase coexistence has been found. For phase coexistence in an applied field, the critical temperatures as a function of the applied field for two different $\mu$ are mapped onto a single curve. The critical densities hardly change as a function of applied field. We also verify that in an applied field the liquid droplets within the two phase coexistence region become elongated in the direction of the field.Comment: 23 pages, ReVTeX, 7 figure

Periodic One-Dimensional Hopping Model with one Mobile Directional Impurity

Analytic solution is given in the steady state limit for the system of Master equations describing a random walk on one-dimensional periodic lattices with arbitrary hopping rates containing one mobile, directional impurity (defect bond). Due to the defect, translational invariance is broken, even if all other rates are identical. The structure of Master equations lead naturally to the introduction of a new entity, associated with the walker-impurity pair which we call the quasi-walker. The velocities and diffusion constants for both the random walker and impurity are given, being simply related to that of the quasi-particle through physically meaningful equations. Applications in driven diffusive systems are shown, and connections with the Duke-Rubinstein reptation models for gel electrophoresis are discussed.Comment: 31 LaTex pages, 5 Postscript figures included, to appear in Journal of Statistical Physic

Wood characteristics of Ceiba pentandra cultivated in upland and floodplain ecosystems.

The present work carried out with native, adult and young trees of the species Ceiba pentrandra (sumauma), cultivated in flood plains (varzea) and in upland (terra firme) ecosystems. The objective was to obtain information about growth patterns of the species and to correlate them with different environmental conditions (varzea e terra firme), as well as to investigate anatomical and physical parameters of the wood. The wood quality of adult native trees was compared with the wood quality of young trees cultivated on varzea and terra firme. Investigations were carried out on the radial variations of density and anisotropy, as well as on the wood anatomical structure on the pith-bark direction on the samples of wood taken at breast height (DBH). From the results obtained, it can be concluded that the cultivated trees on the varzea and in terra firme ecosystems, as well as the native trees, presented an increase of density from pith to bark. The sctructural density of the cultivated trees at the terra firme ecosystem was higher, followed by the trees cultivated at the varzea, when compared with native sumauma. The anisotropy contraction index indicates that sumauma is highly dimensionally unstable. Therefore, its range of use in the area of construction is limited

Feasibility of a Pulsed Ponderomotive Phase Plate for Electron Beams

We propose a scheme for constructing a phase plate for use in an ultrafast Zernike-type phase contrast electron microscope, based on the interaction of the electron beam with a strongly focused, high-power femtosecond laser pulse and a pulsed electron beam. Analytical expressions for the phase shift using the time-averaged ponderomotive potential and a paraxial approximation for the focused laser beam are presented, as well as more rigorous quasiclassical simulations based on the quantum phase integral along classical, relativistic electron trajectories in an accurate, non-paraxial description of the laser beam. The results are shown to agree well unless the laser beam is focused to a waist size below a wavelength. For realistic (off-the-shelf) laser parameters the optimum phase shift of $-\pi/2$ is shown to be achievable. When combined with RF-cavity based electron chopping and compression techniques to produce electron pulses, a femtosecond regime pulsed phase contrast microscope can be constructed. The feasibility and robustness of the scheme are further investigated using the simulations, leading to motivated choices for design parameters such as wavelength, focus size and polarization.Comment: 16 pages, 6 figure

Population-based study of morbidity risk associated with pathological complete response after chemoradiotherapy for rectal cancer

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer may induce a pathological complete response (pCR) but increase surgical morbidity due to radiation-induced fibrosis. In this study the association between pCR and postoperative surgical morbidity was investigated. METHODS: Patients in the Netherlands with rectal cancer who underwent nCRT followed by total mesorectal excision between 2009 and 2017 were included. Data were stratified into patients who underwent resection with creation of a primary anastomosis and those who had a permanent stoma procedure. The association between pCR and postoperative morbidity was investigated in univariable and multivariable logistic regression analyses. RESULTS: pCR was observed in 976 (12·2 per cent) of 8003 patients. In 3472 patients who had a primary anastomosis, the presence of pCR was significantly associated with surgical complications (122 of 443 (27·5 per cent) versus 598 of 3029 (19·7 per cent) in those without pCR) and anastomotic leak (35 of 443 (7·9 per cent) versus 173 of 3029 (5·7 per cent) respectively). Multivariable analysis also showed associations between pCR and surgical complications (adjusted odds ratio (OR) 1·53, 95 per cent c.i. 1·22 to 1·92) and pCR and anastomotic leak (adjusted OR 1·41, 1·03 to 2·05). Of 4531 patients with a permanent stoma, surgical complications were observed in 120 (22·5 per cent) of 533 patients with a pCR, compared with 798 (20·0 per cent) of 3998 patients with no pCR (adjusted OR 1·17, 0·94 to 1·46). CONCLUSION: Patients with a pCR in whom an anastomosis was created were at increased risk of developing an anastomotic leak

Wood characteristics of Ceiba pentandra cultivated in upland and floodplain ecosystem.

The present work was carried out with tree sumauma's tree (nativa, adult and young trees) cultivated in floodplains (varzeas) and uplands (terra firme) ecosystem, having as objective, obtain information about growth patterns of the species and to correlate them into different environmental conditions (floodplain and upland) as well as investigate anatomic and physical parameters of the wood, purposing correlate the wood quality of adult native trees, with young tree's wood, cultivated in floodplain and upland.bitstream/item/180970/1/ID-3837-2-Apendix-1.pd