Towards Integrating Partial Evaluation in a Specialization Framework based on Generic Abstract Interpretation

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Specialization and optimization of constraint programs with dynamic scheduling

In this report we discuss some of the issues involved in the specialization and optimization of constraint logic programs with dynamic scheduling. Dynamic scheduling, as any other form of concurrency, increases the expressive power of constraint logic programs, but also introduces run-time overhead. The objective of the specialization and optimization is to reduce as much as possible such overhead automatically, while preserving the semantics of the original programs. This is done by program transformation based on global analysis. We present implementation techniques for this purpose and report on experimental results obtained from an implementation of the techniques in the context of the CIAO compiler.

Differential elimination by differential specialization of Sylvester style matrices

Differential resultant formulas are defined, for a system $\cP$ of $n$ ordinary Laurent differential polynomials in $n-1$ differential variables. These are determinants of coefficient matrices of an extended system of polynomials obtained from $\cP$ through derivations and multiplications by Laurent monomials. To start, through derivations, a system $\ps(\cP)$ of $L$ polynomials in $L-1$ algebraic variables is obtained, which is non sparse in the order of derivation. This enables the use of existing formulas for the computation of algebraic resultants, of the multivariate sparse algebraic polynomials in $\ps(\cP)$, to obtain polynomials in the differential elimination ideal generated by $\cP$. The formulas obtained are multiples of the sparse differential resultant defined by Li, Yuan and Gao, and provide order and degree bounds in terms of mixed volumes in the generic case.

Molecular adaptation of Ammonia Monooxygenase during independent pH specialization in Thaumarchaeota

Acknowledgements. This work was funded by Natural Environment Research Council Fellowship NE/J019151/1 and by institutional funding from within the University of Aberdeen.

Espin Contains an Additional Actin-binding Site in Its N Terminus and Is a Major Actin-bundling Protein of the Sertoli Cell–Spermatid Ectoplasmic Specialization Junctional Plaque

The espins are actin-binding and -bundling proteins localized to parallel actin bundles. The 837-amino-acid “espin” of Sertoli cell–spermatid junctions (ectoplasmic specializations) and the 253-amino-acid “small espin” of brush border microvilli are splice isoforms that share a C-terminal 116-amino-acid actin-bundling module but contain different N termini. To investigate the roles of espin and its extended N terminus, we examined the actin-binding and -bundling properties of espin constructs and the stoichiometry and developmental accumulation of espin within the ectoplasmic specialization. An espin construct bound to F-actin with an approximately threefold higher affinity (Kd = ∼70 nM) than small espin and was ∼2.5 times more efficient at forming bundles. The increased affinity appeared to be due to an additional actin-binding site in the N terminus of espin. This additional actin-binding site bound to F-actin with a Kd of ∼1 μM, decorated actin stress fiber-like structures in transfected cells, and was mapped to a peptide between the two proline-rich peptides in the N terminus of espin. Espin was detected at ∼4–5 × 106 copies per ectoplasmic specialization, or ∼1 espin per 20 actin monomers and accumulated there coincident with the formation of parallel actin bundles during spermiogenesis. These results suggest that espin is a major actin-bundling protein of the Sertoli cell–spermatid ectoplasmic specialization.

Evolutionary specialization of the nuclear targeting apparatus

The α- and β-karyopherins (Kaps), also called importins, mediate the nuclear transport of proteins. All α-Kaps contain a central domain composed of eight approximately 40 amino acid, tandemly arranged, armadillo-like (Arm) repeats. The number and order of these repeats have not changed since the common origin of fungi, plants, and mammals. Phylogenetic analysis suggests that the various α-Kaps fall into two groups, α1 and α2. Whereas animals encode both types, the yeast genome encodes only an α1-Kap. The β-Kaps are characterized by 14–15 tandemly arranged HEAT motifs. We show that the Arm repeats of α-Kaps and the HEAT motifs of β-Kaps are similar, suggesting that the α-Kaps and β-Kaps (and for that matter, all Arm and HEAT repeat-containing proteins) are members of the same protein superfamily. Phylogenetic analysis indicates that there are at least three major groups of β-Kaps, consistent with their proposed cargo specificities. We present a model in which an α-independent β-Kap progenitor gave rise to the α-dependent β-Kaps and the α-Kaps.

Feeding specialization and host-derived chemical defense in Chrysomeline leaf beetles did not lead to an evolutionary dead end

Combination of molecular phylogenetic analyses of Chrysomelina beetles and chemical data of their defensive secretions indicate that two lineages independently developed, from an ancestral autogenous metabolism, an energetically efficient strategy that made the insect tightly dependent on the chemistry of the host plant. However, a lineage (the interrupta group) escaped this subordination through the development of a yet more derived mixed metabolism potentially compatible with a large number of new host-plant associations. Hence, these analyses on leaf beetles document a mechanism that can explain why high levels of specialization do not necessarily lead to “evolutionary dead ends.”

Molecular organization of the postsynaptic specialization

A specific set of molecules including glutamate receptors is targeted to the postsynaptic specialization of excitatory synapses in the brain, gathering in a structure known as the postsynaptic density (PSD). Synaptic targeting of glutamate receptors depends on interactions between the C-terminal tails of receptor subunits and specific PDZ domain-containing scaffold proteins in the PSD. These scaffold proteins assemble a specialized protein complex around each class of glutamate receptor that functions in signal transduction, cytoskeletal anchoring, and trafficking of the receptors. Among the glutamate receptor subtypes, the N-methyl-d-aspartate receptor is relatively stably integrated in the PSD, whereas the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor moves in and out of the postsynaptic membrane in highly dynamic fashion. The distinctive cell biological behaviors of N-methyl-d-aspartate and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors can be explained by their differential interactions with cytoplasmic proteins.

The Alliance for Progress; a hemispheric response to a global threat.

Mode of access: Internet.

Pathogenic specialization in cereal rust fungi, especially Puccinia recondita f. sp. tritici: concepts, methods of study, and application

Issued in cooperation with Kansas Agricultural Experiment Station.

Hemispheric cooperation in the administration of justice.

Mode of access: Internet.

Morphological and physiological specialization for digging in amphisbaenians, an ancient lineage of fossorial vertebrates

Amphisbaenians are legless reptiles that differ significantly from other vertebrate lineages. Most species dig underground galleries of similar diameter to that of the animal. We studied the muscle physiology and morphological attributes of digging effort in the Brazilian amphisbaenid Leposternon microcephalum (Squamata; Amphisbaenia), which burrows by compressing soil against the upper wall of the tunnel by means of upward strokes of the head. The individuals tested (

Specialization in pyramidal cell structure in the sensory-motor cortex of the vervet monkey (Cercopethicus pygerythrus)

Recent studies have revealed systematic differences in the pyramidal cell structure between functionally related cortical areas of primates. Trends for a parallel in pyramidal cell structure and functional complexity have been reported in visual, somatosensory, motor, cingulate and prefrontal cortex in the macaque monkey cortex. These specializations in structure have been interpreted as being fundamental in determining cellular and systems function, endowing circuits in these different cortical areas with different computational power. In the present study we extend our initial finding of systematic specialization of pyramidal cell structure in sensory-motor cortex in the macaque monkey [Cereb Cortex 12 (2002) 1071] to the vervet monkey. More specifically, we investigated pyramidal cell structure in somatosensory and motor areas 1/2, 5, 7, 4 and 6. Neurones in fixed, flat-mounted, cortical slices were injected intracellularly with Lucifer Yellow and processed for a light-stable 3,3'-diaminobenzidine reaction product. The size of, number of branches in, and spine density of the basal dendritic arbors varied systematically such that there was a trend for increasing complexity in arbor structure with progression through 1/2, 5 and 7. In addition, cells in area 6 were larger, more branched, and more spinous than those in area 4. (c) 2005 IBRO. Published by Elsevier Ltd. All rights reserved.