Solar wind disturbances in th outer heliosphere caused by successive solar flares from the same active region

Solar wind disturbances caused by successive flares from the same active region are traced to about 20 AU, using the modeling method developed by Hakamada and Akasofu (1982). It is shown that the flare-generated shock waves coalesce with the co-rotating interaction region of the interplanetary magnetic field, resulting in a large-scale magnetic field structure in the outer heliosphere. Such a structure may have considerable effects on the propagation of galactic cosmic rays

Selection and Performance Analysis of Asia-Pacific Hedge Funds

This paper studies portfolio selection and performance analysis of hedge funds whose locations or investment targets are Asian-Pacific region. Utilizing Eurekahedge database, we investigate the characteristics of the funds' returns and optimization methods to create a fund of funds. Moreover, we decompose the returns of the hedge funds into risk factors which are observable in financial markets such as stock indices. Then, we attempt to manage a fund of funds by applicating those analyses.

Fabrication of carbon nanotube/NiOx(OH)y nanocomposite by pulsed electrodeposition for supercapacitor applications

Nanocomposite films based on carbon nanotubes (CNTs)/nickel (Ni)-species were fabricated by electrophoretic deposition (EPD) of CNT, followed by pulsed electrodeposition of Ni and annealing in air. NiO/Ni(OH)2 particles with 7 ± 4 nm diameters were uniformly dispersed on the CNT networks. Cyclic voltammetry revealed that the CNT/NiOx(OH)y nanocomposite films had high specific capacitances of 1451, 1158, 998, 896 and 851 F g^{−1} per mass of active Ni species at 1, 10, 30, 50 and 100 mV s^{−1}, respectively, in the potential window of 0.4 V. An annealing time of 1 h (at 523 K) enhanced the pseudocapacity of deposited Ni species by the dehydration of Ni(OH)2 to form NiO. Longer annealing time reduced the capacitance because of sintering and subsequent decrease in surface area of Ni deposits. The capacitance of the fabricated CNT/NiOx(OH)y nanocomposite was maintained after 20, 000 cycles of potential sweeping

The solar wind disappearance event of 11 May 1999: source region evolution

Context. A recent, detailed study of the well-known solar wind disappearance event of 11 May 1999 traced its origin to a coronal hole (CH) lying adjacent to a large active region (AR), AR8525 in Carrington rotation 1949. The AR was located at central meridian on 05 May 1999 when the flows responsible for this event began. We examine the evolution of the AR-CH complex during 5-6 May 1999 to study the changes that apparently played a key role in causing this disappearance event. Aims. To study the evolution of the solar source region of the disappearance event of 11 May 1999. Methods. Using images from the Soft X-ray Telescope (SXT), the Extreme-ultraviolet Imaging Telescope (EIT) and the Michelson Doppler Imager (MDI) to examine the evolution of the CH and AR complex at the source region of the disappearance event. Results. We find a dynamic evolution taking place in the CH-AR boundary at the source region of the disappearance event of 11 May 1999. This evolution, which is found to reduce the area of the CH, is accompanied by the formation of new loops in EUV images that are spatially and temporally correlated with emerging flux regions as seen in MDI data. Conclusions. In the period leading up to the disappearance event of 11 May 1999, our observations, during quiet solar conditions and in the absence of CMEs, provide the first clear evidence for Sun-Earth connection originating from an evolving AR-CH region located at central meridian. With the exception of corotating interacting regions (CIR), these observations provide the first link between the Sun and space weather effects at 1 AU, arising from non-explosive solar events.Comment: The paper has recently been accepted in A&A letters and this version is an 8 page article with 4 figure

Effects of mutations in the helix G region of horseradish peroxidase

Horseradish peroxidase (HRP) has long attracted intense research interest and is used in many biotechnological fields, including diagnostics, biosensors and biocatalysis. Enhancement of HRP catalytic activity and/or stability would further increase its usefulness. Based on prior art, we substituted solvent-exposed lysine and glutamic acid residues near the proximal helix G (Lys 232, 241; Glu 238, 239) and between helices F and F′ (Lys 174). Three single mutants (K232N, K232F, K241N) demonstrated increased stabilities against heat (up to 2-fold) and solvents (up to 4-fold). Stability gains are likely due to improved hydrogen bonding and space-fill characteristics introduced by the relevant substitution. Two double mutants showed stability gains but most double mutations were non-additive and non-synergistic. Substitutions of Lys 174 or Glu 238 were destabilising. Unexpectedly, notable alterations in steady-state Vm/E values occurred with reducing substrate ABTS (2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)), despite the distance of the mutated positions from the active site

Solar Wind and its Evolution

By using our previous results of magnetohydrodynamical simulations for the solar wind from open flux tubes, I discuss how the solar wind in the past is different from the current solar wind. The simulations are performed in fixed one-dimensional super-radially open magnetic flux tubes by inputing various types of fluctuations from the photosphere, which automatically determines solar wind properties in a forward manner. The three important parameters which determine physical properties of the solar wind are surface fluctuation, magnetic field strengths, and the configuration of magnetic flux tubes. Adjusting these parameters to the sun at earlier times in a qualitative sense, I infer that the quasi-steady-state component of the solar wind in the past was denser and slightly slower if the effect of the magneto-centrifugal force is not significant. I also discuss effects of magneto-centrifugal force and roles of coronal mass ejections.Comment: 6 pages, 1 figure, Earth, Planets, & Space in press (based on 5th Alfven Conference) correction of discussion on a related pape

Unravelling the Yeast Cell Cycle Using the TriGen Algorithm

Analyzing microarray data represents a computational challenge due to the characteristics of these data. Clustering techniques are widely applied to create groups of genes that exhibit a similar behavior under the conditions tested. Biclustering emerges as an improvement of classical clustering since it relaxes the constraints for grouping allowing genes to be evaluated only under a subset of the conditions and not under all of them. However, this technique is not appropriate for the analysis of temporal microarray data in which the genes are evaluated under certain conditions at several time points. In this paper, we present the results of applying the TriGen algorithm, a genetic algorithm that finds triclusters that take into account the experimental conditions and the time points, to the yeast cell cycle problem, where the goal is to identify all genes whose expression levels are regulated by the cell cycle