605 research outputs found
A characterization of Q-polynomial association schemes
We prove a necessary and sufficient condition for a symmetric association
scheme to be a Q-polynomial scheme.Comment: 8 pages, no figur
Non-equilibrium behavior of the magnetization in the helimagnetic phases of the rare earth alloys R_{1-x}Y_{x} (R = Gd, Tb, Dy)
We have performed DC and AC magnetization measurements for the rare-earth
magnetic alloy systems Gd_{0.62}Y_{0.38}, Tb_{0.86}Y_{0.14}, and
Dy_{0.97}Y_{0.03}. These materials commonly exhibit a proper helical magnetic
structure, and ferromagnetic structure at lower temperatures.In all of these
materials, a difference between zero-field-cooled (ZFC) magnetization and
field-cooled (FC) magnetization and a hysteresis loop in the M-H curve have
been observed in the helimagnetic phases. The non-equilibrium behavior is
possibly caused by a common nature, e. g., chiral domain structures. In
addition to the above behavior, strong non-linearity of the magnetization and
slow spin dynamics have been observed around the N'eel temperature only in
GdY. The spin-glass like behavior observed in
Gd_{0.62}Y_{0.38} could be related to a novel glassy state such as a
helical-glass state.Comment: 7pages 4 figures, 20th International Conference on Magnetism
(ICM2015
High-speed and Non-volatile Memory Devices Using a Macroscopic Polarized Stack Consisting of Double Floating Gates Interconnected with Engineered Tunnel Oxide Barriers
Importance of physicians’ attire: factors influencing the impression it makes on patients, a cross-sectional study
Ca(2+)/CaM serine/threonine kinase II (CaMKII) is a central molecule in mechanisms of synaptic plasticity and memory. A vital feature of CaMKII in plasticity is its ability to switch to a calcium (Ca(2+)) independent constitutively active state after autophosphorylation at threonine 287 (T287). A second pair of sites, T306 T307 in the calmodulin (CaM) binding region once autophosphorylated, prevent subsequent CaM binding and inactivates the kinase during synaptic plasticity and memory. Recently a synaptic molecule called Ca(2+)/CaM-dependent serine protein kinase (CASK) has been shown to control both sets of CaMKII autophosphorylation events and hence is well poised to be a key regulator of memory. We show deletion of full length CASK or just its CaMK-like and L27 domains disrupts middle-term memory (MTM) and long-term memory (LTM), with CASK function in the α′/β′ subset of mushroom body neurons being required for memory. Likewise directly changing the levels of CaMKII autophosphorylation in these neurons removed MTM and LTM. The requirement of CASK and CaMKII autophosphorylation was not developmental as their manipulation just in the adult α′/β′ neurons was sufficient to remove memory. Overexpression of CASK or CaMKII in the α′/β′ neurons also occluded MTM and LTM. Overexpression of either Drosophila or human CASK in the α′/β′ neurons of the CASK mutant completely rescued memory, confirming that CASK signaling in α′/β′ neurons is necessary and sufficient for Drosophila memory formation and that the neuronal function of CASK is conserved between Drosophila and human. At the cellular level CaMKII overexpression in the α′/β′ neurons increased activity dependent Ca(2+) responses while reduction of CaMKII decreased it. Likewise reducing CASK or directly expressing a phosphomimetic CaMKII T287D transgene in the α′/β′ similarly decreased Ca(2+) signaling. Our results are consistent with CASK regulating CaMKII autophosphorylation in a pathway required for memory formation that involves activity dependent changes in Ca(2+) signaling in the α′/β′ neurons
The Effect of Human Walking on Distribution Characteristics of Indoor Particulate Matter
In modern society, house dust particulate matters pollution had become serious. Ventilation is an important method for removing house dust particulate matters and it is very important to explore the removal efficiency of house dust particulate matters under different ventilation modes. This study analyses the removal effect of house dust particulate matters under the two typical ventilation modes called ceiling exhaust and slit exhaust strategy through experiments and date analysis. In the process of experiments, riboflavin particles were used as the house dust particulate matters, instantaneous microbial detection (IMD) was used to measure the house dust particulate matters. Walking test was carried on after the ventilation system running for some time, which aimed to explore the influence of human behaviour on the house dust particulate matters distribution under two different ventilation modes. It is concluded that larger size particles had larger sedimentation velocity and sedimentation velocity of particles would be faster significantly after the ventilation system working. After walking experiment, particles concentration returned to background concentrations due to the effect of the ventilation system. Particles concentration in slit exhaust strategy was lower than ceiling exhaust so that the effect of slit exhaust strategy is superior to the ceiling exhaust
A Programming Environment for Visual Block-Based Domain-Specific Languages
AbstractVisual block-based programming is useful for various users such as novice programmers because it provides easy operations and improves the readability of programs. Also, in programming education, it is known to be effective to initially present basic language features and then gradually make more advanced features available. However, the cost of implementing such visual block-based languages remains a challenge. In this paper, we present a programming environment for providing visual block-based domain- specific languages (visual DSLs) that are translatable into various programming languages. In our environment, programs are built by combining visual blocks expressed in a natural language. Blocks represent program elements such as operations and variables. Tips represent snippets, and macro blocks represent procedures. Using Tips and macros make code more abstract, and reduce the number of blocks in code. Visual DSLs can be a front-end for various languages. It can be easily restricted and extended by adding and deleting blocks. We applied our programming environment to Processing, an educational programming language for media art. We show that the environment is useful for novice programmers who learn basic concepts of programming and the features of Processing
Excess caffeine exposure impairs eye development during chick embryogenesis
Caffeine has been an integral component of our diet and medicines for centuries. It is now known that over consumption of caffeine has detrimental effects on our health, and also disrupts normal foetal development in pregnant mothers. In this study, we investigated the potential teratogenic effect of caffeine over-exposure on eye development in the early chick embryo. Firstly, we demonstrated that caffeine exposure caused chick embryos to develop asymmetrical microphthalmia and induced the orbital bone to develop abnormally. Secondly, caffeine exposure perturbed Pax6 expression in the retina of the developing eye. In addition, it perturbed the migration of HNK-1(+) cranial neural crest cells. Pax6 is an important gene that regulates eye development, so altering the expression of this gene might be the cause for the abnormal eye development. Thirdly, we found that reactive oxygen species (ROS) production was significantly increased in eye tissues following caffeine treatment, and that the addition of anti-oxidant vitamin C could rescue the eyes from developing abnormally in the presence of caffeine. This suggests that excess ROS induced by caffeine is one of the mechanisms involved in the teratogenic alterations observed in the eye during embryogenesis. In sum, our experiments in the chick embryo demonstrated that caffeine is a potential teratogen. It causes asymmetrical microphthalmia to develop by increasing ROS production and perturbs Pax6 expression
- …