Pancreatic xanthomatous neuropathy associated with hyperlipidemia: a cause of abdominal pain mimicking chronic pancreatitis

"Hyperlipidemic crisis" is a term used to describe episodic abdominal pain in patients with hyperlipidemia. The morphologic correlates of this phenomenon have not been investigated and the etiology of the disorder is uncertain. We report a unique histologic finding in the pancreas of a 34-year-old woman with a 17-year history of episodic abdominal pain, sometimes accompanied by hyperamylasemia. At the age of 18 years, grossly elevated cholesterol and triglyceride levels were documented and type V hyperlipidemia was diagnosed. At the age of 34 years, subtotal pancreatectomy was performed for intractable abdominal pain. Histologic examination identified an increased number of enlarged pancreatic nerves that were infiltrated by foamy macrophages and encircled by fibrous tissue; endoneurial infiltration with macrophages occasionally split nerves into individual fascicles. Otherwise, the pancreas had only minimal fibrosis, nesidioblastosis, mucinous metaplasia of some pancreatic ducts, and scattered small collections of chronic inflammatory cells, subtle features suggesting very mild chronic pancreatitis. We propose that this novel xanthomatous neuropathy mimicked pancreatitis and was one of the underlying pathophysiologic mechanisms of abdominal pain in this patient. Further studies are necessary to document the prevalence of this new entity in patients with hyperlipidemia and to correlate its occurrence with "hyperlipidemic crisis" in those individuals.     

Constraint Lingo: towards high‐level constraint programming

Logic programming requires that the programmer convert a problem into a set of constraints based on predicates. Choosing the predicates and introducing appropriate constraints can be intricate and error prone. If the problem domain is structured enough, we can let the programmer express the problem in terms of more abstract, higher‐level constraints. A compiler can then convert the higher‐level program into a logic‐programming formalism. The compiler writer can experiment with alternative low‐level representations of the higher‐level constraints in order to achieve a high‐quality translation. The programmer can then take advantage of both a reduction in complexity and an improvement in runtime speed for all problems within the domain. We apply this analysis to the domain of tabular constraint‐satisfaction problems. Examples of such problems include logic puzzles solvable on a hatch grid and combinatorial problems such as graph coloring and independent sets. The proper abstractions for these problems are rows, columns, entries, and their interactions. We present a higher‐level language, Constraint Lingo, dedicated to problems in this domain. We also describe how we translate programs from Constraint Lingo into lower‐level logic formalisms such as the logic of propositional schemata. These translations require that we choose among competing lower‐level representations in order to produce efficient results. The overall effectiveness of our approach depends on the appropriateness of Constraint Lingo, our ability to translate Constraint Lingo programs into high‐quality representations in logic formalisms, and the efficiency with which logic engines can compute answer sets. We comment on our computational experience with these tools in solving both graph problems and logic puzzles. Copyright © 2004 John Wiley & Sons, Ltd.     

Impossible differential cryptanalysis of 7-round Advanced Encryption Standard (AES)

In 2000, Biham and Keller [Cryptanalysis of reduced variants of Rijndael, 3rd AES Conference, in press] presented an impossible differential cryptanalysis of the Advanced Encryption Standard (AES) up to 5 rounds. This was later improved in 2001 by Cheon et al. [Improved impossible differential cryptanalysis of Rijndael and Crypton, in: Lecture Notes in Comput. Sci., vol.  2288, Springer-Verlag, Berlin, 2001, pp. 39-49] to apply to 6 rounds of the AES. In this paper, we extend on previous results to present an attack on the AES up to 7 rounds. This is the best-known impossible differential attack on the AES, and works by exploiting weaknesses in the AES key schedule.     

Structure formation in grade 20 steel during equal-channel angular pressing and subsequent heating

The structure formation and the mechanical properties of quenched and tempered grade 20 steel after equal-channel angular pressing (ECAP) at various true strains and 400°C are studied. Electron microscopy analysis after ECAP shows a partially submicrocrystalline and partially subgrain structure with a structural element size of 340–375 nm. The structural element size depends on the region in which the elements are formed (polyhedral ferrite, needle-shaped ferrite, tempered martensite, and pearlite). Heating of the steel after ECAP at 400 and 450°C increases the fraction of high-angle boundaries and the structural ferrite element size to 360–450 nm. The fragmentation and spheroidization of cementite lamellae of pearlite and subgrain coalescence in the regions of needle-shaped ferrite and tempered martensite take place at a high ECAP true strain and heating temperature. Structural refinement ensures considerable strengthening, namely, UTS 742–871 MPa at EL 11–15.3%. The strength slightly increases, whereas the plasticity slightly decreases when the true strain increases during ECAP. After ECAP and heating, the strength and plastic properties of the grade 20 steel remain almost the same.     

Master equations for Wigner functions with spontaneous collapse and their relation to thermodynamic irreversibility

Journal of Computational Electronics - Wigner functions, allowing for a reformulation of quantum mechanics in phase space, are of central importance for the study of the quantum-classical...     

Strips of hourly power options—Approximate hedging using average-based forward contracts

We study approximate hedging strategies for a contingent claim consisting of a strip of independent hourly power options. The payoff of the contingent claim is a sum of the contributing hourly payoffs. As there is no forward market for specific hours, the fundamental problem is to find a reasonable hedge using exchange-traded forward contracts, e.g. average-based monthly contracts. The main result is a simple dynamic hedging strategy that reduces a significant part of the variance. The idea is to decompose the contingent claim into mathematically tractable components and to use empirical estimations to derive hedging deltas. Two benefits of the method are that the technique easily extends to more complex power derivatives and that only a few parameters need to be estimated. The hedging strategy based on the decomposition technique is compared with dynamic delta hedging strategies based on local minimum variance hedging, using a correlated traded asset.     

Oil‐spill cleanup: The influence of acetylated curaua fibers on the oil‐removal capability of magnetic composites

A magnetic resin based on cardanol, furfural, and curaua fibers was prepared and characterized. The material could be used in oil‐spill cleanup processes, because of its aromatic/aliphatic balance. The resin was prepared through bulk polycondensation of cardanol and furfural in the presence of curaua fibers and maghemite nanoparticles. Hydrophobicity of the curaua fibers was improved by acetylation, increasing the oil‐absorbing capability of the composites. The obtained magnetic composites were studied by Fourier‐transform infrared spectroscopy, X‐ray diffraction, and thermogravimetric analysis. Degree of cure, magnetic force, and oil‐removal capability tests were also performed. The results show that the composites possess an elevated cure degree in addition to a considerable magnetic force. The materials exhibit a good oil removal capability in the presence of a magnetic field, which is improved by the use of acetylated curaua. In the best case, the composite filled with maghemite and curaua can remove 12 parts of oil from water. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41732.