The search for IDDM susceptibility genes: the next generation

Two human chromosomal regions, the HLA region on chromosome 6p2l and the insulin gene region on chromosome 11p15, have been investigated in detail for more than 10 years for the presence of IDDM susceptibility genes. Recent genome searches indicate the possible existence of many additional susceptibility genes in IDDM. The lengthy and protracted studies to prove the linkage and identity of the susceptibility genes in the HLA and insulin gene regions provide a perspective and background for understanding the complexities and time course for characterization of the putative additional IDDM susceptibility genes uncovered by genome searches.     

Adding a temporal dimension to a logic system

We introduce a methodology whereby an arbitrary logic system L can be enriched with temporal features to create a new system T(L). The new system is constructed by combining L with a pure propositional temporal logic T (such as linear temporal logic with Since and Until) in a special way. We refer to this method as adding a temporal dimension to L or just temporalising L. We show that the logic system T(L) preserves several properties of the original temporal logic like soundness, completeness, decidability, conservativeness and separation over linear flows of time. We then focus on the temporalisation of first-order logic, and a comparison is make with other first-order approaches to the handling of time.     

Counting networks with arbitrary fan-out

Summary It is shown that an acyclic smoothing network (and hence counting network) with fan-outn cannot be constructed from balancers of fan-outb ₁,...,b _k , if there exists a prime factorp ofn, such thatp does not divideb _i , for alli, 1ik. This holds regardless of the depth, fan-in or size of the network, as long as they are finite. On the positive side, a simple construction ofcyclic counting networks with fan-outn, for arbitraryn, is presented. An acyclic counting network with fan-in and fan-outp2 ^k , for any integerk0, is constructed out of 2-balancers andp-balancers. Eran Aharonson received the B.A. and M.Sc. degrees in Computer Science from the Technion, Israel Institute of Technology (Haifa, Israel) in 1989 and 1992, respectively. He is currently vice president for research and development at ART-Advanced Recognition Technolgies Ltd., a company dedicated to handwriting and voice recognition. His general research interests are distributed computation, theoretical computer science and pattern recognition. Hagit Attiya received the B.Sc. degree in Mathematics and Computer Science from the Hebrew University of Jerusalem, in 1981, the M.Sc. and Ph.D. degrees in Computer Science from the Hebrew University of Jerusalem, in 1983 and 1987, respectively. She is presently a senior lecturer at the department of Computer Science at the Technion, Israel Institute of Technology. Prior to this, she has been a post-doctoral research associate at the Laboratory for Computer Science at M.I.T. Her general research interests are distributed computation and theoretical computer science. More specific interests include fault-tolerance, timing-based and asynchronous algorithms.A preliminary version of this paper appears in proceedings of the3rd Annual ACM-SIAM Symposium on Discrete Algorithms, January 1992, pp. 104–113. This research was supported by Technion V.P.R.-B. and G. Greenberg Research Fund (Ottawa)Supported by Rashi Enterprise graduate fellowship     

Kinetics of the thermal oxidation of isotactic poly(1-pentene)

The kinetics of the thermal oxidation of isotactic poly(1-pentene) was studied in the bulk phase. The experimental data were obtained from the quantitative estimation of carbonyl groups formed in the non-volatile oxidation products using infra-red spectroscopy. Reaction temperature varied from 100° to 115° and oxygen concentrations from 10% to 100% by volume. A general kinetic scheme and mathematical expressions previously reported for the thermal autoxidation of polyolefins satisfactorily explained the experimental results. Activation energies of this polymer for various steps in the kinetic scheme were compared with polypropylene and poly(1-butene).     

Highly concurrent multi-word synchronization

The design of concurrent data structures is greatly facilitated by the availability of synchronization operations that atomically modify $k$ arbitrary items, such as $k$-read–modify–write ($k\text{<mi mathsize="small" is="true">RMW</mi>}$). Aiming to increase concurrency in order to exploit the parallelism offered by today’s multi-core and multi-processing architectures, we propose a highly concurrent software implementation of $k\text{<mi mathsize="small" is="true">RMW</mi>}$, with only constant space overhead. Our algorithm ensures that two operations delay each other only if they are within distance $O\left(k\right)$ in the conflict graph, induced by the operations’ data items.The algorithm uses double compare-and-swap (dcas). When dcas is not supported by the architecture, the algorithm of Attiya and Dagan (2001) [3] can be used to replace dcas with (unary) cas, with only a slight increase in the interference among operations.     

Rationally Designed Vanadium Pentoxide as High Capacity Insertion Material for Mg‐Ion

Owing to high energy density and economic viability, rechargeable Mg batteries are considered alternatives to lithium ion batteries. However besides the chevrel phase, none of the conventional inorganic cathode materials demonstrate reversible intercalation/deintercalation of Mg⁺² ions in an anhydrous electrolyte system. The lack of high voltage and high capacity cathode frustrates the realization of Mg batteries. Previous studies indicate that vanadium pentoxide (V₂O₅) has the potential to reversibly insert/extract Mg ions. However, many attempts to utilize V₂O₅ demonstrate limited electrochemical response, due to hindered Mg ion mobility in solid. Here, monodispersed spherical V₂O₅ with a hierarchical architecture is rationally designed, through a facile and scalable approach. The V₂O₅ spheres exhibit initial discharge capacity of 225 mA h g^?1 which stabilizes at ≈190 mA h g^?1 at 10 mA g^?1, much higher than previous reports. The V₂O₅ spheres exhibit specific discharge capacity of 55 mA h g^?1 at moderate current rate (50 mA g^?1) with negligible fading after 50 cycles (≈5%) and 100 cycle (≈13%), while it retains ≈95% columbic efficiency after 100 cycles demonstrating excellent stability during Mg⁺² ion intercalation/deintercalation. Most interestingly, exact phase and morphology are completely retained even after repeated Mg⁺² ion intercalation/deintercalation at different current rates, demonstrating pronounced electrochemical activity in an anhydrous magnesium electrolyte.     

Curry-Howard for incomplete first-order logic derivations using one-and-a-half level terms

The Curry-Howard correspondence connects derivations in natural deduction with the lambda-calculus. Predicates are types, derivations are terms. This supports reasoning from assumptions to conclusions, but we may want to reason backwards; from the desired conclusion towards the assumptions. At intermediate stages we may have a partial derivation, with holes.This is natural in informal practice but it can be difficult to formalise. The informal act of filling holes in a partial derivation suggests a capturing substitution, since holes may occur in the scope of quantifier introduction rules. As other authors have observed, this is not immediately supported by the lambda-calculus. Also, universal quantification requires a ‘fresh name’ and it is not immediately obvious what formal meaning to assign to this notion if derivations are incomplete. Further issues arise with proof-normalisation; this corresponds with lambda-calculus reduction, which can require alpha-conversion to avoid capture when beta-reducing, and it is not immediately clear how to alpha-convert a name in an incomplete derivation. We apply a one-and-a-half level technique based on nominal terms to construct a Curry-Howard correspondence for first-order logic. This features two levels of variable, but with no lambda-abstraction at the second level. Predicates are types, derivations are terms, proof-normalisation is reduction — and the two levels of variable are, respectively, the assumptions and the holes of an incomplete derivation.We give notions of proof-term, typing, alpha-conversion and beta-reduction for our syntax. We prove confluence, we exhibit several admissible rules including a proof that instantiation of level two variables is type-safe — this corresponds with the act of filling holes in an incomplete derivation, and can be viewed as a form of Cut-rule — and we explore the connection with traditional Curry-Howard in the case that the derivation is in fact complete.Our techniques are not specifically tailored to first-order logic and the same ideas should be applicable without any essential new difficulties to similar logical systems.     

Is PTSD-Phenotype Associated with HPA-Axis Sensitivity?: The Endocannabinoid System in Modulating Stress Response in Rats

Endocannabinoids play a role in adaptation to stress and regulate the release of glucocorticoids in stressed and unstressed conditions. We recently found that basal corticosterone pulsatility may significantly impact the vulnerability for developing post-traumatic-stress-disorder (PTSD), suggesting that the endocannabinoid system may contribute to its development. To examine this, we exposed rats to predator scent stress (PSS). Behavioral reactions were recorded seven days post-PSS. Cerebrospinal fluid (CSF) was collected from anesthetized rats shortly after PSS exposure to determine the levels of 2-arachidonoyl glycerol (2-AG) and anandamide (AEA). To correlate between endocannabinoids and corticosterone levels, rats were placed in metabolic cages for urine collection. To assess the levels of endocannabinoids in specific brain regions, rats’ brains were harvested one day after behavioral analysis for staining and fluorescence quantification. Moreover, 2-AG was elevated in the CSF of PTSD-phenotype rats as compared with other groups and was inversely correlated with corticosterone urinary secretion. Eight days post-PSS exposure, hippocampal and hypothalamic 2-AG levels and hippocampal AEA levels were significantly more reduced in the PTSD-phenotype group compared to other groups. We posit that maladaptation to stress, which is propagated by an abnormal activation of endocannabinoids, mediates the subsequent stress-induced behavioral disruption, which, later, reduces neuronal the expression of endocannabinoids, contributing to PTSD symptomology.