Parallel query processing with zigzag trees

In this article, we describe our approach to the compile-time optimization and parallelization of queries for execution in DBS3 or EDS. DBS3 is a shared-memory parallel database system, while the EDS system has a distributed-memory architecture. Because DBS3 implements a parallel dataflow execution model, this approach applies to both architectures. Using randomized search strategies enables the exploration of a search space large enough to include zigzag trees, which are intermediate between left-deep and right-deep trees. Zigzag trees are shown to provide better response time than right-deep trees in case of limited memory. Performance measurements obtained using the DBS3 prototype show the advantages of zigzag trees under various conditions.     

Long-term functional outcome following transient middle cerebral artery occlusion in the rat: Correlation between brain damage and behavioral impairment.

The assessment of both histological and functional long-term outcomes after cerebral ischemia is increasingly recommended for preclinical studies. Whereas correlations between behavioral impairments and primary ischemic lesion are documented, little is known about their relationships with remote nonischemic regions that undergo secondary degeneration, such as the thalamus. Anesthetized rats were subjected to mild (30 min) or severe (60 min) occlusion of the middle cerebral artery. Two months after ischemia, sensorimotor behavior was assessed according to the neurological score, limb-placing, adhesive-removal, and staircase tests; the final histological lesion was measured after this assessment. Cortical damage was correlated to all transient and long-lasting sensorimotor deficits, whereas striatal lesion was more consistently reflected by the forelimb-placing reflexes and adhesive-removal motor deficits. By contrast, the thalamic atrophy was not correlated to early neurological impairment, but rather to the late sensory deficit at the adhesive-removal test and to the skilled forepaw reaching alteration at the staircase test. This suggests that thalamus contributes, albeit moderately, to the ischemia-induced long-lasting sensorimotor deficits, some of which represent relevant targets for therapeutic interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adrenocortical overexpression of gastric inhibitory polypeptide receptor underlies food-dependent Cushing's syndrome

Abnormal responsiveness of adrenocortical cells to gastric inhibitory polypeptide (GIP) in food-dependent Cushing's syndrome suggested that adrenal expression of ectopic, overexpressed, or mutated GIP receptor (GIPR) underlies this syndrome. The expression of GIPR was studied by RT-PCR in human adrenal tissues from two patients with GIP-dependent Cushing's syndrome (adenoma, bilateral hyperplasia), five fetal or adult controls, one patient with Cushing's disease, and four patients with non-food-dependent cortisol-secreting adenomas or bilateral hyperplasias and compared to that in normal pancreas. Hybridization of the RT-PCR-amplified ribonucleic acids with the human GIPR complementary DNA showed an overexpression of GIPR in the adrenals of the two GIP-dependent Cushing's syndrome patients compared to that in normal adrenal tissues (2-3 orders of magnitude) or pancreas (10-fold); no signal could be seen in adrenal adenomas or macronodular hyperplasia from cases of non-food-dependent Cushing's syndrome. No mutation of the GIPR was identified by sequencing the full-length receptor in GIP-dependent adrenal tissue. New alternative spliced isoforms of the GIPR were found, but are identical in GIP-dependent and normal adrenal tissues. Incubation of adrenal cells with GIP stimulates cortisol secretion in GIP-dependent, but not in normal fetal, adult, or non-food-dependent Cushing's syndrome, adrenals. We conclude that the GIPR overexpression and its coupling to steroidogenesis underlie GIP-dependent Cushing's syndrome.     

Comparative determinations of the /spl chi//sup (2)/ spatial distribution induced in thermally poled silica planar samples

We herein report the comparison of two independent reconstructions of the distribution of the /spl chi//sup (2)/ nonlinear susceptibility induced by thermal poling in planar silica samples. Both nonlinear profiles are quantitatively in good agreement in terms of /spl chi//sup (2)/ magnitude and nonlinear thickness; and qualitatively in agreement in terms of shape. We conclude that both characterization methods used are efficient for the determination of the /spl chi//sup (2)/ susceptibility spatial distribution in bulk samples.     

A Technical Word- and Term-Translation Aid Using Noisy Parallel Corpora across Language Groups

Technical-term translation represents one of the most difficult tasks for human translators since (1) most translators are not familiar with terms and domain-specific terminology and (2) such terms are not adequately covered by printed dictionaries. This paper describes an algorithm for translating technical words and terms from noisy parallel corpora across language groups. Given any word which is part of a technical term in the source language, the algorithm produces a ranked candidate match for it in the target language. Potential translations for the term are compiled from the matched words and are also ranked. We show how this ranked list helps translators in technical-term translation. Most algorithms for lexical and term translation focus on Indo-European language pairs, and most use a sentence-aligned clean parallel corpus without insertion, deletion or OCR noise. Our algorithm is language- and character-set-independent, and is robust to noise in the corpus. We show how our algorithm requires minimum preprocessing and is able to obtain technical-word translations without sentence-boundary identification or sentence alignment, from the English–Japanese awk manual corpus with noise arising from text insertions or deletions and on the English–Chinese HKUST bilingual corpus. We obtain a precision of 55.35% from the awk corpus for word translation including rare words, counting only the best candidate and direct translations. Translation precision of the best-candidate translation is 89.93% from the HKUST corpus. Potential term translations produced by the program help bilingual speakers to get a 47% improvement in translating technical terms.     

Preparation and chemical transformation of surfactant-templated hybrid phase containing [MoS4] anions

Exchange reaction between (NH₄)₂MoS₄ and CTABr in aqueous solution produces lamellar compound (CTA)₂MoS₄, which after a treatment with aqueous N₂H₄ under the mild conditions transforms to a lamellar mesophase containing [Mo₂O₂S₂(S₂)₂]²⁻ anions.     

Edge detection: what about rotation invariance?

In this article, we consider techniques that provide edge strength at each pixel using two orthogonal directions and question their invariance with respect to a rotation.     

Comparison of the sensitivity of commercial strains and infant isolates of bifidobacteria to antibiotics and bacteriocins

Eighteen bifidobacteria, six isolated from infant feces and 12 commercial strains (of which 10 were purchased from the American Type Culture Collection), were tested for sensitivity to 14 antibiotics and four bacteriocins including nisin A, nisin Z, pediocin PA-1 and mutacin B-Ny266. All bacteria were resistant to vancomycin, kanamycin, neomycin and streptomycin. Infant isolates were more sensitive than commercial strains to cloxacillin, ampicillin, chloramphenicol, tetracycline, rifampicin and novobiocin. Sensitivity to bacteriocins determined by a microplate assay varied widely. Generally, nisin A was the most effective bacteriocin followed by nisin Z and mutacin B-Ny266. Pediocin PA-1 appeared to have no inhibition at 70 μg mL⁻¹. Commercial strains showed relatively variable sensitivity to bacteriocins compared to infant isolates, which were inhibited within a narrow range of bacteriocin concentration. Bacteriocin tolerance could be easily gained by prolonging the exposure time. Death–time curves and transmission electron microscopy (TEM) of logarithmic and stationary cells of two strains (Bifidobacterium adolescentis ATCC 15704 and infant isolate Bifidobacterium sp. RBL67) incubated with twice the minimum inhibitory concentration of nisin A and nisin Z for 3 h revealed that log-phase cells were more sensitive than stationary-phase cells. TEM showed that the cell membrane is the most likely site of bactericidal effects of nisin.