FTIR reflectance vs. EPR studies of structural iron in kaolinites

International audienc

Effects of electrical stimulation of dorsal raphe nucleus on neuronal response properties of barrel cortex layer IV neurons following long-term sensory deprivation

Abstract: Objective To evaluate the effect of electrical stimulation of dorsal raphe nucleus (DRN) on response properties of layer IV barrel cortex neurons following long-term sensory deprivation. Methods: Male Wistar rats were divided into sensory-deprived (SD) and control (unplucked) groups. In SD group, all vibrissae except the D2 vibrissa were plucked on postnatal day one, and kept plucked for a period of 60 d. After that, whisker regrowth was allowed for 8-10 d. The D2 principal whisker (PW) and the D1 adjacent whisker (AW) were either deflected singly or both deflected in a serial order that the AW was deflected 20 ms before PW deflection for assessing lateral inhibition, and neuronal responses were recorded from layer IV of the D2 barrel cortex. DRN was electrically stimulated at inter-stimulus intervals (ISIs) ranging from 0 to 800 ms before whisker deflection. Results: PW-evoked responses increased in the SD group with DRN electrical stimulation at ISIs of 50 ms and 100 ms, whereas AW-evoked responses increased at ISI of 800 ms in both groups. Whisker plucking before DRN stimulation could enhance the responsiveness of barrel cortex neurons to PW deflection and decrease the responsiveness to AW deflection. DRN electrical stimulation significantly reduced this difference only in PW-evoked responses between groups. Besides, no DRN stimulation-related changes in response latency were observed following PW or AW deflection in either group. Moreover, condition test (CT) ratio increased in SD rats, while DRN stimulation did not affect the CT ratio in either group. There was no obvious change in 5-HT2A receptor protein density in barrel cortex between SD and control groups. Conclusion: These results suggest that DRN electrical stimulation can modulate information processing in the SD barrel cortex

Physics demos for all UVEG degrees: a unique project in Spain

The Physics Demo Project at the University of Valencia (www.uv.es/fisicademos) has developed a collection of physics demonstrations to be used during lectures. It consists of more than 130 experimental demos about different physics topics. More than 30 professors borrow them whenever they lecture on physics in any of our 40 courses in 17 different science or technical degrees, involving 246 ECTS and more than 3500 students. Each demo kit with a simple experimental set displays a particular physics phenomenon. An on-line user guide highlights the main physics principles involved, instructions on how to use it and advices of how to link it to the theoretical concepts or to technical applications. Demo lectures (and collections) are a usual and widespread practice in many countries but not in Spain. This unique initiative aims at the recovery of this practice by involving a growing collaborative team of users and with the aid of educational innovation projects. Here we explain the project content, organization and recent developments. Our experience, together with the positive students comments, allows us to draw the following conclusions: demos introduce the real sensible world in the lecture hall, providing the necessary link between concepts and everyday life, and becoming, again, something more than "chalk and talk"

Male and female physical intimate partner violence and socioeconomic position: a cross-sectional international multicentre study in Europe

Objectives: This work explores the association between socioeconomic position (SEP) and intimate partner violence (IPV) considering the perspectives of men and women as victims, perpetrators and as both (bidirectional). Study Design: Cross-sectional international multicentre study. Methods: A sample of 3496 men and women, (aged 18-64 years), randomly selected from the general population of residents from six European cities was assessed: Athens, Budapest, London, Östersund, Porto and Stuttgart. Their education (primary, secondary and university), occupation (upper white-collar, lower white-collar and blue collar) and unemployment duration (never, ≤12 months and >12 months) were considered as SEP indicators and physical IPV was measured with the Revised Conflict Tactics Scales. Results: Past year physical IPV was declared by 17.7% of women (3.5% victims, 4.2% perpetrators and 10.0% bidirectional) and 19.8% of men (4.1% victims, 3.8% perpetrators and 11.9% bidirectional). Low educational level (primary vs. university) was associated with female victimization (adjusted Odds Ratio, 95% confidence interval: 3.2, 1.3-8.0) and with female bidirectional IPV (4.1, 2.4-7.1). Blue collar occupation (vs. upper white) was associated with female victimization (2.1, 1.1-4.0), female perpetration (3.0, 1.3-6.8) and female bidirectional IPV (4.0, 2.3-7.0). Unemployment duration was associated with male perpetration (> 12 months of unemployment vs. never unemployed: 3.8, 1.7-8.7) and with bidirectional IPV in both sex (women: 1.8, 1.2-2.7; men: 1.7, 1.0-2.8). Conclusions: In these European centers, physical IPV was associated with a disadvantaged socioeconomic position. A consistent socioeconomic gradient was observed in female bidirectional involvement, but victims or perpetrators-only presented gender specificities according to levels of education, occupation differentiation and unemployment duration potentially useful for designing interventions

Measurement of Jet Shapes in Photoproduction at HERA

The shape of jets produced in quasi-real photon-proton collisions at centre-of-mass energies in the range $134-277$ GeV has been measured using the hadronic energy flow. The measurement was done with the ZEUS detector at HERA. Jets are identified using a cone algorithm in the $\eta - \phi$ plane with a cone radius of one unit. Measured jet shapes both in inclusive jet and dijet production with transverse energies $E^{jet}_T>14$ GeV are presented. The jet shape broadens as the jet pseudorapidity ($\eta^{jet}$) increases and narrows as $E^{jet}_T$ increases. In dijet photoproduction, the jet shapes have been measured separately for samples dominated by resolved and by direct processes. Leading-logarithm parton-shower Monte Carlo calculations of resolved and direct processes describe well the measured jet shapes except for the inclusive production of jets with high $\eta^{jet}$ and low $E^{jet}_T$. The observed broadening of the jet shape as $\eta^{jet}$ increases is consistent with the predicted increase in the fraction of final state gluon jets.Comment: 29 pages including 9 figure

Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse

Observation of Scaling Violations in Scaled Momentum Distributions at HERA

Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of $x$ and $Q^2$ using the ZEUS detector. The evolution of the scaled momentum, $x_p$, with $Q^2,$ in the range 10 to 1280 $GeV^2$, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of $Q^2$.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

D* Production in Deep Inelastic Scattering at HERA

This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0 \to K^- \pi^+) \pi^+$ (+ c.c.) has been used in the study. The $e^+p$ cross section for inclusive D^{*\pm} production with $5<Q^2<100 GeV^2$ and $y<0.7$ is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {$1.3<p_T(D^{*\pm})<9.0$ GeV and $| \eta(D^{*\pm}) |<1.5$}. Differential cross sections as functions of p_T(D^{*\pm}), $\eta(D^{*\pm}), W$ and $Q^2$ are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and $\eta$(D^{*\pm}), the charm contribution $F_2^{c\bar{c}}(x,Q^2)$ to the proton structure function is determined for Bjorken $x$ between 2 $\cdot$ 10$^{-4}$ and 5 $\cdot$ 10$^{-3}$.Comment: 17 pages including 4 figure