Secure software infrastructure in the internet age

The rapid growth and penetration of the Internet are now leading us to a world where networks are ubiquitous and everything is connected. Breaking the distance barrier by the ubiquitous connection, however, is a two-edged sword. Our network infrastructure today is still fragile and thus “everything is connected” may simply mean “everything can be attacked from whatever place on the earth.” In this paper, we first point out the importance and inherent problems of software systems that underlay open and extensible networks, especially the Internet. We put emphasis on software since software vulnerabilities account for most attacks, incidents, or even disasters on the Internet today. Next we present general ideas of promising techniques in defense of software systems, including theoretical, language-based, and runtime solutions. Finally, we show our experience in developing a secure mail system. Etsuya Shibayama, D.Sc.: He is a professor of the Graduate School of Information Science and Engineering at Tokyo Institute of Technology. He received B.Sc. and M.Sc. in mathematical sciences from Kyoto University in 1981 and 1983, respectively, and D.Sc. in information science from the University of Tokyo in 1991. He is interested in various topics in software including design and implementation of textual and visual programming languages, system software, and user interface software. Recently, he has been doing research on language-based software security and methodologies for building secure software. Akinori Yonezawa, Ph.D.: He is a Professor of computer science at Department of Computer Science, the University of Tokyo. He received his Ph.D. in Computer Science form the Massachusetts Institute of Technology in 1977. His current major research interests are in the areas of concurrent/parallel computation models, programming languages, object-oriented computing and distributed computing. He is the designer of and object-oriented concurrent language ABCL/1 and the editor of several books and served as an associate editor of ACM Transaction of Programming Language and Systems (TOPLAS). Since 1998, he has been an ACM Fellow.     

Quantitative analysis of adherent cell orientation influenced by strong magnetic fields

Examines the effect of strong magnetic fields on adherent cells. Smooth muscle cells, cultured in 8- or 14-T superconducting magnets for three days, exhibited orientational order parallel to the magnetic field direction. To discuss the process and the mechanism of the orientation, the orientational characteristic of the cell culture was investigated with quantitative measurements: an orientational order parameter and the Fourier transform (FT) analysis. The orientational order parameter indicates the degree of orientation. The value of the parameter was estimated with the FT of microscopic images. The cells cultured under stronger static magnetic fields exhibited stronger ordering, while they showed weaker ordering in the control when they were cultured under a strong magnetic gradient force of 400 T/sup 2//m. The ordering was enhanced under uniform strong magnetic fields, while it was not affected or was suppressed by the strong gradient force. We suggest that the cells organize themselves to minimize their diamagnetic torsion stresses, which can be induced in the uniform magnetic fields by the membrane's diamagnetic anisotropy.     

Study on the curing behavior of resol. IV. Comparison of the curing behavior of resols prepared with either sodium hydroxide or barium hydroxide

Curing behaviors of two kinds of resols prepared by the reaction of phenol (1 mol), formaldehyde (1.2 mol), and either sodium hydroxide (0.02 mol) or barium hydroxide (0.01 mol), were examined at 120°C by means of Curelastometer, IR spectroscopy, THE extraction, and GPC. Gelling and curing speeds of the resol prepared with barium hydroxide as catalyst (BR) were faster than with sodium hydroxide (NR). The amount of hydroxymethyl groups in BR also decreased more rapidly with an increase in the cure time than that in NR by IR spectrometry. Similar results were confirmed by THF extraction and GPC. It is recognized in the curing of both resols that relatively higher molecular weight compounds gel rapidly and that, after major components in the resol have changed to gel, low molecular weight compounds still remain in the resol as sol state. It is inferred from GPC that NR differs from BR in the molecular weight of the compounds which exist prior to gel formation, namely, the molecular weight of the compounds in BR is smaller than that in NR.     

Properties of Taeniolite/Acriflavine Complex Film Before and After Carbonization: Effect of Acriflavine Content

Taeniolite/acriflavine complexes (TAC) intercalated with various amounts of acriflavine were synthesized. The films derived from these complexes and raw taeniolite (TNL) as a reference were heated (carbonized) below 1273 K under a nitrogen atmosphere, followed by measurements of mechanical properties and electrical resistivity. Compared with TNL film, TAC films, especially with an amount of acriflavine equivalent to the cation exchange capacity of TNL, showed higher thermostability, higher flexibility, lower tensile strength, and larger modulus of toughness. Electrical resistivities of TAC films decreased remarkably after heating to 873 K or higher, in contrast to no change for TNL film. After heating to 1073 K, the electrical resistivities of TAC films clearly decreased with an increase of acriflavine content. This difference disappeared after heating to 1273 K. These behaviors are discussed on the basis of X-ray diffraction, IR spectroscopy. SEM observation, and so on.     

Distribution of bubble properties in a gas-liquid-solid fluidized bed

The behavior of bubbles in a cocurrent gas-liquid-solid fluidized bed was investigated in a column of 76.2 mm ID in this study. The particles used were glass beads of 3 and 6 mm and a binary mixture of these particles. A novel dual electrical resistivity probe system was developed and utilized to obtain bubble properties including bubble size and rise velocity. The distributions of the bubble properties in the gas-liquid-solid fluidized bed were evaluated for three flow regimes: the dispersed bubble flow regime; the coalesced bubble flow regime; and the slug flow regime.     

Effect of Argon-Based Atmospheric Pressure Plasma Treatment on Hard Tissue Formation on Titanium Surface

In this paper, we suggest that the atmospheric pressure plasma treatment of pure titanium metal may be useful for improving the ability of rat bone marrow cells (RBMCs) to induce hard tissue differentiation. Previous studies have reported that the use of argon gas induces a higher degree of hard tissue formation. Therefore, this study compares the effects of plasma treatment with argon gas on the initial adhesion ability and hard tissue differentiation-inducing ability of RBMCs. A commercially available titanium metal plate was used as the experimental material. A plate polished using water-resistant abrasive paper #1500 was used as the control, and a plate irradiated with argon mixed with atmospheric pressure plasma was used as the experimental plate. No structural change was observed on the surface of the titanium metal plate in the scanning electron microscopy results, and no change in the surface roughness was observed via scanning probe microscopy. X-ray photoelectron spectroscopy showed a decrease in the carbon peak and the formation of hydroxide in the experimental group. In the distilled water drop test, a significant decrease in the contact angle was observed for the experimental group, and the results indicated superhydrophilicity. Furthermore, the bovine serum albumin adsorption, initial adhesion of RBMCs, alkaline phosphatase activity, calcium deposition, and genetic marker expression of rat bone marrow cells were higher in the experimental group than those in the control group at all time points. Rat distal femur model are used as in vivo model. Additionally, microcomputed tomography analysis showed significantly higher results for the experimental group, indicating a large amount of the formed hard tissue. Histopathological evaluation also confirmed the presence of a prominent newly formed bone seen in the images of the experimental group. These results indicate that the atmospheric pressure plasma treatment with argon gas imparts superhydrophilicity, without changing the properties of the pure titanium plate surface. It was also clarified that it affects the initial adhesion of bone marrow cells and the induction of hard tissue differentiation.     

Six-helix and eight-helix DNA nanotubes assembled from half-tubes

DNA nanotubes are cylinder-like structures formed from DNA double-helical molecules whose helix axes are fused at least twice by crossovers. It is potentially useful to use such tubes as sheaths around rodlike species that arise in biological systems and in nanotechnology. It seems easiest to obtain such sheathing by joining two or more components around an object rather than attempting to thread the object through a cavity in the tube. We report two examples of tubes containing a specific number of helices that are assembled from half-tube components. These tubes are a six-helix bundle and an eight-helix bundle, constructed respectively from two bent triple-crossover (BTX) molecules and from two four-helix arched motifs. Both species contain single strands in one molecule that are missing in its mate. The six-helix bundle is formed from two different BTX molecules, whereas the eight-helix species is a closed cyclic dimer of the same molecule. We demonstrate the formation of these species by gel electrophoresis, and we examine their arrangement into long one-dimensional arrays by means of atomic force microscopy.     

Capacitive sensing of electrocardiographic potential through cloth from the dorsal surface of the body in a supine position: a preliminary study

A method for obtaining electrocardiographic potential through thin cloth inserted between the measuring electrodes and the skin of a subject's dorsal surface when lying supine has been proposed. The method is based on capacitive coupling involving the electrode, the cloth, and the skin. Examination of a pilot device which employed the method revealed the following: (1) In spite of the gain attenuation in the high frequency region, the proposed method was considered useful for monitoring electrogardiogram (ECG) for nondiagnostic purpose. (2) The method was able to yield a stable ECG from a subject at rest for at least 7 h, and there was no significant adverse effect of long-term measurement on the quality of the signal obtained. (3) Electrode area was the factor that had most influence on the signal, compared with other factors such as cloth thickness and coupling pressure, but could be reduced to 10 cm2 for heart rate detection. (4) Input capacitance of the device was assumed to be the dominant factor for the gain attenuation in the high frequency region, and should be reduced with a view to diagnostic use. Although there is still room for improvement in terms of practical use, the proposed method appears promising for application to bedding as a noninvasive and awareness-free method for ECG monitoring.