Mediated catalysis of Paracoccus pantotrophus cytochrome c peroxidase by P. pantotrophus pseudoazurin: kinetics of intermolecular electron transfer

J Biol Inorg Chem (2007) 12:691–698 DOI 10.1007/s00775-007-0219-9

Does the sun shine by p p or CNO fusion reactions?

We show that solar neutrino experiments set an upper limit of 7.8% (7.3% including the recent KamLAND measurements) to the fraction of energy that the Sun produces via the CNO fusion cycle, which is an order of magnitude improvement upon the previous limit. New experiments are required to detect CNO neutrinos corresponding to the 1.5% of the solar luminosity that the standard solar model predicts is generated by the CNO cycle.

Same- and Other-Sex Victimization : Risk Factors, Consequences, and Protection by Peers

Bullying can be viewed as goal-oriented behavior in the strive for dominance and prestige in the peer group (Salmivalli, 2010). To ensure the effectiveness of their power demonstrations, bullies often choose targets from among their vulnerable peers (Salmivalli, 2010; Veenstra et al., 2007). A large number of studies have also shown that victimization has severe consequences for the victims’ psychosocial adjustment (Reijntjes, Kamphuis, Prinzie, & Telch, 2010; Ttofi, Farrington, Lösel, & Loeber, 2011). In this thesis I investigate – based on three empirical studies – whether similar dynamics on the risk factors and consequences apply to same- and other-sex victimization. In the empirical studies, we used the data from the randomized control trial of the KiVa antibullying program for the elementary school grades 4–6 (2007–2008), and for the middle school grades 7–9 (2008–2009). We measured same- and other-sex victimization, and victims’ defending relationships by dyadic questions: “By which classmates are you victimized?” and “By which classmates are you supported, comforted, or defended?” In addition, we used self-reports and peer reports to measure adjustment and social status. The findings imply that other-sex victimization may be challenging for antibullying work. First, although targets of bullying seemed to be selected from among vulnerable peers for the most part, perceived popularity increased the risks of other-sex victimization. Popularity of these victims may falsely lead to an impression that the victims are doing well. Second, the consequences considering victims’ later psychosocial adjustment were alarming concerning girls bullied by boys. Thus, despite the fact that the targets may be perceived as popular, other-sex victimization can have even more severe consequences than same-sex victimization. Third, we found that defending relationships were mostly same-sex relationships, and consequently, we may ask whether defending is effective against other-sex bullies. Finally, the KiVa antibullying program was less effective against other-sex victimization in the adolescent sample. The findings altogether emphasize the importance of taking into account the sex composition of the bully-victim dyad, both considering future research on bullying and in the antibullying work with children and adolescents.

Genetic and temporal aspects of protection by kanamycin against cochlear noise injury

Experiments explored the minimal kanamycin dosing regimen that renders protection against noise induced hearing loss in young CBA/J mice. We also tested the age-dependence of protection in CBA/J as well as the dependence of protection on a particular genetic background in experiments using young C57BL/6J and CBA/CaJ mice.

Involvement of ERK, Akt and JNK signalling in H2O2-induced cell injury and protection by hydroxytyrosol and its metabolite homovanillic alcohol

The olive oil polyphenol, hydroxytyrosol (HT), is believed to be capable of exerting protection against oxidative kidney injury. In this study we have investigated the ability of HT and its O-methylated metabolite, homovanillic alcohol (HVA) to protect renal cells against oxidative damage induced by hydrogen peroxide. We show that both compounds were capable of inhibiting hydrogen peroxide-induced kidney cell injury via an ability to interact with both MAP kinase and PI3 kinase signalling pathways, albeit at different concentrations. HT strongly inhibited death and prevented peroxide-induced increases in ERK1/2 and JNK1/2/3 phosphorylation at 0.3 microM, whilst HVA was effective at 10 microM. At similar concentrations, both compounds also prevented peroxide-induced reductions in Akt phosphorylation. We suggest that one potential protective effect exerted by olive oil polyphenols against oxidative kidney cell injury may be attributed to the interactions of HT and HVA with these important intracellular signalling pathways.

Boundary of the rauzy fractal sets in R x C generated by P(x)=x(4)-x(3)-x(2)-x-1

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermo-reversible sol-gel transition of TiO2 nanoparticles with surface modified by p-toluene sulfonic acid

In this paper an unprecedent thermo-reversible sol-gel transition for titania nanoparticles dispersed in a solution of p-toluene sulfonic acid (PTSH) in isopropanol is reported. The sol formed by the thermo-hydrolysis at 60 degrees C of titanium tetraisopropoxide (Ti((OPr)-Pr-i)(4)) reversibly changes into a turbid gel upon cooling to room temperature. Turbidimetric measurements performed for samples containing different nominal acidity ratios (A = [PTSH]/[Ti]) have evidenced that the gel transformation temperature increases from 20 to 35 degrees C as the [PTSH]/[Ti] ratio increases from 0.2 to 2.0. SAXS results indicate that the thermo-reversible gelation is associated to a reversible aggregation of a monodisperse set of titania nanoparticles with average gyration radius of approximate to 2 nm. From the different PTSH species evidenced by Raman spectroscopy and TG/DTA of dried gels we proposed that the then-no-reversible gelation in this systems is induced by the formation of a supramolecular network, in which the protonated surface of nanoparticles is interconnected through cooperative hydrogen bonds between -SO3 groups of p-toluene sulfonic acid. (C) 2009 Elsevier Ltd. All rights reserved.

Boundary of the rauzy fractal sets in ℝ×ℂgenerated by p(x) = x 4- x 3 - x 2 -x- 1

We study the boundary of the 3-dimensional Rauzy fractal ε ⊂ ℝ×ℂ generated by the polynomial P(x) Dx 4-x 3-x 2-x-1. The finite automaton characterizing the boundary of ε is given explicitly. As a consequence we prove that the set ε has 18 neighboors where 6 of them intersect the central tile ε in a point. Our construction shows that the boundary is generated by an iterated function system starting with 2 compact sets.

Development and simulation of DSP filters for transformer differential protection / by Oskar Reynisson.

Transformer protection is one of the most challenging applications within the power system protective relay field. Transformers with a capacity rating exceeding 10 MVA are usually protected using differential current relays. Transformers are an aging and vulnerable bottleneck in the present power grid; therefore, quick fault detection and corresponding transformer de-energization is the key element in minimizing transformer damage. Present differential current relays are based on digital signal processing (DSP). They combine DSP phasor estimation and protective-logic-based decision making. The limitations of existing DSP-based differential current relays must be identified to determine the best protection options for sensitive and quick fault detection. The development, implementation, and evaluation of a DSP differential current relay is detailed. The overall goal is to make fault detection faster without compromising secure and safe transformer operation. A detailed background on the DSP differential current relay is provided. Then different DSP phasor estimation filters are implemented and evaluated based on their ability to extract desired frequency components from the measured current signal quickly and accurately. The main focus of the phasor estimation evaluation is to identify the difference between using non-recursive and recursive filtering methods. Then the protective logic of the DSP differential current relay is implemented and required settings made in accordance with transformer application. Finally, the DSP differential current relay will be evaluated using available transformer models within the ATP simulation environment. Recursive filtering methods were found to have significant advantage over non-recursive filtering methods when evaluated individually and when applied in the DSP differential relay. Recursive filtering methods can be up to 50% faster than non-recursive methods, but can cause false trip due to overshoot if the only objective is speed. The relay sensitivity is however independent of filtering method and depends on the settings of the relay’s differential characteristics (pickup threshold and percent slope).