Can energetic terahertz pulses initiate surface catalytic reactions on the picosecond time scale?

In preparation for picosecond pump-probe experiments at the SwissFEL X-ray laser facility, the feasibility of collectively initiating surface chemical reactions using energetic pulses of terahertz radiation is being tested.     

A Practical-Time Related-Key Attack on the KASUMI Cryptosystem Used in GSM and 3G Telephony

Over the last 20 years, the privacy of most GSM phone conversations was protected by the A5/1 and A5/2 stream ciphers, which were repeatedly shown to be cryptographically weak. They are being replaced now by the new A5/3 and A5/4 algorithms, which are based on the block cipher KASUMI. In this paper we describe a new type of attack called a sandwich attack, and use it to construct a simple related-key distinguisher for 7 of the 8 rounds of KASUMI with an amazingly high probability of 2^?14. By using this distinguisher and analyzing the single remaining round, we can derive the complete 128-bit key of the full KASUMI with a related-key attack which uses only 4 related keys, 2²⁶ data, 2³⁰ bytes of memory, and 2³² time. These completely practical complexities were experimentally verified by performing the attack in less than two hours on a single-core of a PC. Interestingly, neither our technique nor any other published attack can break the original MISTY block cipher (on which KASUMI is based) significantly faster than exhaustive search. Our results thus indicate that the modifications made by ETSI’s SAGE group in moving from MISTY to KASUMI made it extremely weak when related-key attacks are allowed, but do not imply anything about its resistance to single-key attacks. Consequently, there is no indication that the way KASUMI is implemented in GSM and 3G networks is practically vulnerable in any realistic attack model.     

Hidden and under control

Network covert channels are policy-breaking and stealthy communication channels in computer networks. These channels can be used to bypass Internet censorship, to exfiltrate data without raising attention, to allow a safe and stealthy communication for members of political oppositions and for spies, to hide the communication of military units at the battlefield from the enemy, and to provide stealthy communication for today’s malware, especially for botnets. To enhance network covert channels, researchers started to add protocol headers, so-called micro-protocols, to hidden payload in covert channels. Such protocol headers enable fundamental features such as reliability, dynamic routing, proxy capabilities, simultaneous connections, or session management for network covert channels—features which enrich future botnet communications to become more adaptive and more stealthy than nowadays. In this survey, we provide the first overview and categorization of existing micro-protocols. We compare micro-protocol features and present currently uncovered research directions for these protocols. Afterwards, we discuss the significance and the existing means for micro-protocol engineering. Based on our findings, we propose further research directions for micro-protocols. These features include to introduce multi-layer protocol stacks, peer auto-configuration, and peer group communication based on micro-protocols, as well as to develop protocol translation in order to achieve inter-connectivity for currently separated overlay networks.     

Molecular and Signaling Mechanisms for Docosahexaenoic Acid-Derived Neurodevelopment and Neuroprotection

The neurodevelopmental and neuroprotective actions of docosahexaenoic acid (DHA) are mediated by mechanisms involving membrane- and metabolite-related signal transduction. A key characteristic in the membrane-mediated action of DHA results from the stimulated synthesis of neuronal phosphatidylserine (PS). The resulting DHA-PS-rich membrane domains facilitate the translocation and activation of kinases such as Raf-1, protein kinase C (PKC), and Akt. The activation of these signaling pathways promotes neuronal development and survival. DHA is also metabolized in neural tissues to bioactive mediators. Neuroprotectin D1, a docosatriene synthesized by the lipoxygenase activity, has an anti-inflammatory property, and elovanoids formed from DHA elongation products exhibit antioxidant effects in the retina. Synaptamide, an endocannabinoid-like lipid mediator synthesized from DHA in the brain, promotes neurogenesis and synaptogenesis and exerts anti-inflammatory effects. It binds to the GAIN domain of the GPR110 (ADGRF1) receptor, triggers the cAMP/protein kinase A (PKA) signaling pathway, and activates the cAMP-response element binding protein (CREB). The DHA status in the brain influences not only the PS-dependent signal transduction but also the metabolite formation and expression of pre- and post-synaptic proteins that are downstream of the CREB and affect neurotransmission. The combined actions of these processes contribute to the neurodevelopmental and neuroprotective effects of DHA.     

Network Virtualization: A Viable Path Towards the Future Internet

New technologies as well as new ways of using network services are rapidly changing the Internet’s landscape. These developments will have far-reaching implications for the architecture of the networks of the future. However, the current Internet design is plagued with a number of fundamental limitations, which makes its use as the sole basis for the networking applications of the future questionable. We believe that the Future Internet must allow the co-existence of diverse network designs and paradigms, both new and old, to remain open to innovation and meet the challenges of the future. In this paper, we propose to use network virtualization, embedded in an architectural framework, to achieve this goal and to lay the foundation for the deployment of novel concepts such as content-centric networking.

增糖方法对灰比诺葡萄酒质量的影响

对4种调整糖度方法对葡萄酒质量的影响进行了比较,采用的葡萄品种为灰比诺,可溶性固形物为19.5°Brix,通过不同的调整糖度措施使可溶性目形物提高2.5°Brix,达到22°Brix.4种调整糖度方法分别为:直接往葡萄汁中加入蔗糖;往葡萄汁中加入68°Brix浓缩葡萄汁;冷冻除冰使葡萄汁浓缩和借助反渗透机器浓缩葡萄汁.结果表明,在调整糖度幅度为2.5°Brix的情况下,不同调整糖度方法对葡萄酒的质量影响不大.     

STUDY OF THE REFRACTORY PROPERTIES OF TOPAZ*

The effect of heat treatments on the chemical, physical, and mineralogical properties of topaz is described. The samples were obtained from a deposit of potential commercial importance. Brick made from calcined and uncalcined topaz were tested according to standard A.S.T.M. test methods, and the results are presented.     

Polymorphic Systems with Arrays, 2-Counter Machines and Multiset Rewriting

Polymorphic systems with arrays (PSAs) is a general class of nondeterministic reactive systems. A PSA is polymorphic in the sense that it depends on a signature, which consists of a number of type variables, and a number of symbols whose types can be built from the type variables. Some of the state variables of a PSA can be arrays, which are functions from one type to another. We present several new decidability and undecidability results for parameterised control-state reacha- bility problems on subclasses of PSAs.     

On globalisation and diversity

Mary Kalantzis's plenary address at the 2005 International Conference on the Humanities (Cambridge, U.K.) argues that globalization and diversity ground the world of our times. The article expands on this notion as Kalantzis and co-author Bill Cope describe three instantiations of globalization since the evolutionary processes of human beings began. The third globalization of which we are a part today, they argue, is characterized by layers upon layers of difference. These layers, moreover, are supported through new media and the Internet—and may indeed return us to “multilingualism, divergence, and enduringly deep diversity.”     

Tungsten carbides as substitutes of platinoids in heterogeneous catalysis I. The effect of surface composition on the reactivity of methylcyclopentane on tungsten carbides

Reactions of methylcyclopentane on tungsten carbides show that in presence of oxygen the extensive hydrogenolysis is inhibited in favour of ring enlargement and ring opening via a bifunctional mechanism due to the coexistence of surface acid-rearrangement and hydrogenation-dehydrogenation sites. The oxycarbidic materials are very active and selective in skeletal rearrangement of hydrocarbons.