LNCS

Reachability analysis is difficult for hybrid automata with affine differential equations, because the reach set needs to be approximated. Promising abstraction techniques usually employ interval methods or template polyhedra. Interval methods account for dense time and guarantee soundness, and there are interval-based tools that overapproximate affine flowpipes. But interval methods impose bounded and rigid shapes, which make refinement expensive and fixpoint detection difficult. Template polyhedra, on the other hand, can be adapted flexibly and can be unbounded, but sound template refinement for unbounded reachability analysis has been implemented only for systems with piecewise constant dynamics. We capitalize on the advantages of both techniques, combining interval arithmetic and template polyhedra, using the former to abstract time and the latter to abstract space. During a CEGAR loop, whenever a spurious error trajectory is found, we compute additional space constraints and split time intervals, and use these space-time interpolants to eliminate the counterexample. Space-time interpolation offers a lazy, flexible framework for increasing precision while guaranteeing soundness, both for error avoidance and fixpoint detection. To the best of out knowledge, this is the first abstraction refinement scheme for the reachability analysis over unbounded and dense time of affine hybrid systems, which is both sound and automatic. We demonstrate the effectiveness of our algorithm with several benchmark examples, which cannot be handled by other tools

The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequence

Shell disease in Crangon crangon (Linnaeus, 1758): the interaction of temperature and stress response

The prevalence of black spot shell disease is increasing among marine crustaceans worldwide. Rising seawater temperatures – often stressful for ectothermic species – are assumed to enhance the occurrence of shell disease. In the North Sea > 50% of local populations of the brown shrimp (Crangon crangon) are affected by the disease. While fisheries are suffering because diseased crustaceans are barely merchantable, the impact of shell disease on life history traits of crustaceans is little understood. To determine the role of temperature on the development of black spots and its implications for survival and physiology in the brown shrimp, a prolonged (3 months) thermal stress experiment was performed. We measured the increment of shell disease and the effect of molting in shrimps kept at control (15 °C = equivalent to the seafloor temperature in the North Sea during sampling) and increased temperature (20 °C = according to predictions for the end of the century). The resting metabolic rate was analyzed to determine the physiological state of diseased compared to non-diseased animals. In the present study, the warmer temperature in the range of 20 °C did not increase the spot size of shell disease and no differences were observed between the two temperatures. The process of molting thereby seemed to diminish and in most of the cases even completely remove the signs of shell disease. At 15 °C but not at 20 °C, metabolic rate was reduced in diseased in contrast to healthy individuals. This study showed that shell disease might lead to a higher mortality rate and an impairment of the physiological state in C. crangon

Cornell Veterinary Medicine, Spring 1999

Cornell Veterinary Medicine, Spring 1999Topics of articles in this issue of Cornell Veterinary Medicine include: Cancer Program Integrates Research and Medicine; Translational Biology (Donald F. Smith); Cornell's Canine DNA Files Go International; April Workshop: Human-Animal Bond and Grief; Institute Works to Improve Welfare of Animals; Researchers Identify Cancer-Causing Virus in Breeding-Stock Salmon; Helping Shelter Animals; Pregnancy Research: Low Birth-Weight Risks Begin Early; Collaboration Key to Cancer Program; Research Faculty Discuss the Cancer Program; An Integrated Cancer Program; Toxicology Study: Common Lead-Poisoning Therapy Might Alter Immune System; Book Fund Endowment; People, Honors, and Awards; Planning Your Legacy; Saturday April 10: Community Invited to Open House 1999; In Memoriam (Mendell Bartlett, Arthur S. Charles, Jack Mindell, Kenneth Palmer, Gerald J. Sacks, Richard A. Smith, Frederic B. Thomson, William C. Rebhun); Calendar of Events; Outreach Program Recognized

Nonhermetic Plastic Packaging of High Voltage Electronic Switches Utilizing a Low-Stress Glob Coating for 95/5Pb/Sn Solder Joints of Flip-Chip Bonded Multichip Module High Voltage Devices

©1998 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.AT&T’s number five electronic switching system (ESS) is a state-of-the-art electronic switch that uses solid-state gated-diode-crosspoint (GDX) for fast switching of telephone calls. These GDX’s operate at 375 V and require exceptional protection and reliability performance of these packages. Ceramic hermetic packages were used for these type of devices. In order to reduce the cost of these GDX’s, a new type of flip-chip bonded structure with 95/5 Pb/Sn solder joints GDX’s was developed. These flip-chip GDX’s were surface-mounted on a conventional ceramic substrate. An thixotropic silicone gel was used as an underfill and overfill glob-coating to provide the ultrahigh reliability performance of these high voltage devices and a silicone elastomer was used to pot the hybrid surface-mounted GDX multi-chip module structure to further enhance the robustness of its structure. In this paper, the materials such as the flip-chip solder (95/5 Pb/Sn), silicone gel, and elastomer, and their processes such as flip-chip bumping, reflow, cleaning, encapsulation and reliability testing are described for this robust, high performance and lowcost packages