[en] Highlights: • We consider an important mechanism of early warning for defending a cyber system that has become a key component of constructing network defense in practice. • The reliability function of a system under attack from one or multiple sources is derived. • We propose the optimal strategy for defending a cyber system with early warning components in the worst attack scenario. - Abstract: Due to the increasing reliance on networks, defending a cyber system is of vital importance. In this paper, we consider an important mechanism of early warning for defending a cyber system that has become a key component of constructing network defense in practice. We study the reliability of a system under attack from single or multiple sources. In particular, we discuss the effect of an early warning mechanism on the system reliability. We then propose the optimal strategy for defending a cyber system with early warning components in the worst attack scenario. The theoretical results are further validated by simulation evidence.

[en] According to Ursel Lorenzen, former secretary to the Nato director responsible for theoretical war games, Nato headquarters, Brussels, the Nato alliance plans to make first use of atomic weapons in any conflict with the Soviet bloc. She made this statement at a specially called Press conference in East Berlin, after she had defected to the Russians following 11 years' duty in her sensitive Nato post. The author discusses this statement

[en] This pastoral letter explains the criteria for distinguishing a just from an unjust war. It also contains a commentary on the conduct of war, including the use of nuclear weapons; and an assessment of the current US deterrence policy

[en] The original article needs the addition of another affiliation.

[en] The latest available import data from the US Department of Energy show greater US dependence on imported crude oil, a two percentage point increase in 1992 above 1991. In fact, the share of imported crude oil of the sum of the US crude production and imports has grown from less than one-third in 1986 to nearly 46% in 1992. A closer look at the data reveals that US crude oil dependence is become increasingly centered on a small number of countries. In 1992, more than 85% of crude oil imports originated in seven countries: Saudia Arabia, Nigeria, Venezuela, Canada, Mexico, Angola, and the United Kingdom. Many people worry that US import dependence is at dangerous levels. However, the recent trend of joint ventures between US companies and oil producers should allay those fears by providing oil producers an incentive for stable oil supply in the US

[en] This paper studied the inhibitory effect of pomegranate peel (PP) extract on the growth of Microcystis aeruginosa, the model of harmful algal blooms in aquatic environment. The allelochemicals were identified by HPLC–MS/MS from PP and tested by batch experiment through measurement of algal density, chlorophyll a (Chl-a) concentration, maximum quantum yield of photosystem II (Fv/Fm), superoxide dismutase (SOD), and malondialdehyde (MDA) contents. Results showed that both PP powder and PP extract had obvious inhibitory effect on M. aeruginosa growth. Quercetin and luteolin were identified as the allelochemicals to M. aeruginosa growth. However, the inhibitory capacity of luteolin was stronger than that of quercetin. The growth inhibition ratio of luteolin can reach up to 98.7 and 99.1% of the control on day 7 at the dosages of 7 and 10 mg/L, respectively. Moreover, the changes of Chl-a, Fv/Fm, SOD, and MDA in M. aeruginosa confirmed jointly that the allelochemicals cause inhibition of photosystem and oxidative damage to M. aeruginosa cells with the antioxidant defense system being activated, which leads to the aggravation of membrane lipid peroxidation. Thus, luteolin could be used as a promising algaecide for emergency handling of M. aeruginosa blooms. This study might provide a new direction in the management of eutrophication in the future.

[en] The authors take issue with the assessment that the advent of antisatellite weapons implies that the beneficial role of satellites in arms control, confidence building, and conflict resolution has been judged less important than their ability to support actual military operations. They argue that there is still an opportunity to negotiate a militarily significant and verifiable constraint on the growth of antisatellite technology that would be in the security interest of the US and the world as a whole. They base their opinion on an assessment of the roles of the existing military satellites and their vulnerability to antisatellite weapons and the probable impact of antisatellite weapons on various kinds of crisis and conflict. 10 figures, 1 table

[en] Papers are presented on powder metallurgy in ordnance and other defense-related technologies

[en] Nowadays, there are a lot of defense mechanisms to secure IT-systems against Cyber attacks. Thus, Cyber attacks have to be more sophisticated than they used to be in order to stay undetected as long as possible and to bypass defense mechanisms. As a result, current threats frequently use steganographic techniques to hide malicious functions in a harmless looking carrier. In [1] an attack for Siemens S7 Sirnatic Programmable Logic Controllers (PLCs) is presented, where the control logic of the PLC is modified while the source code which the PLC presents the engineering station is retained. As a result, the PLCs functionality is different from the control logic presented to the engineering station. Furthermore, steganographic techniques are frequently used to hide information in media files.

[en] At Physics Today's invitation, two physicists with opposing views on the proposed Strategic Arms Limitation Talks discuss the arguments for and against US approval