Studies in zirconium oxidation

Study provides insight into the oxidation mechanism of zirconium by combining electrical measurements with oxidation data. The measurement of electrical potential across growing scale on zirconium and the determination of conventional weight-change oxidation data were carried out at 550, 700, and 800 degrees C

Collisional Properties of Cold Spin-Polarized Metastable Neon Atoms

We measure the rates of elastic and inelastic two-body collisions of cold spin-polarized neon atoms in the metastable 3P2 state for 20^Ne and 22^Ne in a magnetic trap. From particle loss, we determine the loss parameter of inelastic collisions beta=6.5(18)x10^{-12} cm^3s^{-1} for 20^Ne and beta=1.2(3)x10^{-11}cm^3{s}^{-1} for 22^Ne. These losses are caused by ionizing (i.e. Penning) collisions %to more than and occur less frequently than for unpolarized atoms. This proves the suppression of Penning ionization due to spin-polarization. From cross-dimensional relaxation measurements, we obtain elastic scattering lengths of a=-180(40) a_0 for 20^Ne and a=+150(+80/-50) a_0 for 22^Ne, where a_0=0.0529 nm.Comment: 4 pages, 3 figure

Aspects of the decoherence in high spin environments: Breakdown of the mean-field approximation

The study of the decoherence of qubits in spin systems is almost restricted to environments whose constituents are spin-$\frac{1}{2}$ particles. In this paper we consider environments that are composed of particles of higher spin, and we investigate the consequences on the dynamics of a qubit coupled to such baths via Heisenberg $XY$ and Ising interactions. It is shown that while the short time decay in both cases gets faster as the magnitude of the spin increases, the asymptotic behavior exhibits an improvement of the suppression of the decoherence when the coupling is through Heisenberg $XY$ interactions. In the case of a transverse Ising model, we find that the mean field approximation breaks down for high values of the spin.Comment: Preprint; 27 pages, 8 figure

Modeling the Effects of Hyaluronic Acid Degradation on the Regulation of Human Astrocyte Phenotype Using Multicomponent Interpenetrating Polymer Networks (mIPNs)

Hyaluronic acid (HA) is a highly abundant component in the extracellular matrix (ECM) and a fundamental element to the architecture and the physiology of the central nervous system (CNS). Often, HA degradation occurs when an overreactive inflammatory response, derived from tissue trauma or neurodegenerative diseases such as Alzheimer’s, causes the ECM in the CNS to be remodeled. Herein, we studied the effects of HA content as a key regulator of human astrocyte (HAf) reactivity using multicomponent interpenetrating polymer networks (mIPNs) comprised of Collagen I, HA and poly(ethylene glycol) diacrylate. The selected platform facilities the modulation of HA levels independently of matrix rigidity. Total astrocytic processes length, number of endpoints, the expression of the quiescent markers: Aldehyde Dehydrogenase 1 Family Member L1 (ALDH1L1) and Glutamate Aspartate Transporter (GLAST); the reactive markers: Glial Fibrillary Acidic Protein (GFAP) and S100 Calcium-Binding Protein β (S100β); and the inflammatory markers: Inducible Nitric Oxide Synthase (iNOS), Interleukin 1β (IL-1β) and Tumor Necrosis Factor Alpha (TNFα), were assessed. Cumulatively, our results demonstrated that the decrease in HA concentration elicited a reduction in the total length of astrocytic processes and an increase in the expression of HAf reactive and inflammatory markers

Low-lignin pulping to replace or enhance oxygen bleaching

"March, 1982.

Electroconvulsive seizures (ECS) do not prevent LPS-induced behavioral alterations and microglial activation

Background: Long-term neuroimmune activation is a common finding in major depressive disorder (MDD). Literature suggests a dual effect of electroconvulsive therapy (ECT), a highly effective treatment strategy for MDD, on neuroimmune parameters: while ECT acutely increases inflammatory parameters, such as serum levels of pro-inflammatory cytokines, there is evidence to suggest that repeated ECT sessions eventually result in downregulation of the inflammatory response. We hypothesized that this might be due to ECT-induced attenuation of microglial activity upon inflammatory stimuli in the brain. Methods: Adult male C57Bl/6J mice received a series of ten electroconvulsive seizures (ECS) or sham shocks, followed by an intracerebroventricular (i.c.v.) lipopolysaccharide (LPS) or phosphate-buffered saline (PBS) injection. Brains were extracted and immunohistochemically stained for the microglial marker ionized calcium-binding adaptor molecule 1 (Iba1). In addition, a sucrose preference test and an open-field test were performed to quantify behavioral alterations. Results: LPS induced a short-term reduction in sucrose preference, which normalized within 3 days. In addition, LPS reduced the distance walked in the open field and induced alterations in grooming and rearing behavior. ECS did not affect any of these parameters. Phenotypical analysis of microglia demonstrated an LPS-induced increase in microglial activity ranging from 84 to 213 % in different hippocampal regions (CA3 213 %; CA1 84 %; dentate gyrus 131 %; and hilus 123 %). ECS-induced alterations in microglial activity were insignificant, ranging from -2.6 to 14.3 % in PBS-injected mice and from -20.2 to 6.6 % in LPS-injected mice. Conclusions: We were unable to demonstrate an effect of ECS on LPS-induced microglial activity or behavioral alterations

De ontwikkeling van de beeldvorming rondom culturele diversiteit bij de Rijksoverheid in de periode 2008-2018.

De manier waarop medewerkers van de Rijksoverheid tegen culturele diversiteit aankijken, speelt een belangrijke rol in het succes van diversiteitsbeleid. In 2008 werd deze beeldvorming al eens Rijksbreed in kaart gebracht. Het hoofddoel van het huidige onderzoek was om te zien in hoeverre de beeldvorming zich in de afgelopen tien jaar heeft ontwikkeld. Daarnaast werd onderzocht of het organisatieklimaat en de leiderschapsstijl van de leidinggevende een rol spelen in de ontwikkeling van de beeldvorming. Het onderzoek werd uitgevoerd d.m.v. een digitale vragenlijst. Respondenten werd gevraagd welke voor- en nadelen van diversiteit zij ervaren op de werkvloer. Er werd een vergelijking gemaakt tussen twee willekeurige steekproeven onder Rijksambtenaren in 2008 (1617 respondenten in 7 kerndepartementen) en 2018 (2024 respondenten in 10 kerndepartementen en 4 uitvoeringsorganisaties). De resultaten laten zien dat Rijksambtenaren in 2018 positiever aankijken tegen culturele diversiteit op de werkvloer dan in 2008. Met name de voordelen voor productiviteit (de business case) worden meer erkend dan voorheen. Werknemers van de Rijksover