State‐space µ analysis for an experimental drive‐by‐wire vehicle

This paper considers the application of the skewed structured singular value to the robust stability of systems subject to strictly real parametric uncertainty. Three state‐space formulations that counteract the discontinuous nature of this problem are detailed. It is shown that the calculation of the supremum of the structured singular value over a frequency range using these formulations transforms into a single skewed structured singular value calculation. Similar to the structured singular value, the exact calculation of the skewed structured singular value is an NP‐hard problem. In this work, two efficient algorithms that determine upper and lower bounds on the skewed structured singular value are presented. These algorithms are critically assessed using a series of robustness analysis tests on a safety‐critical experimental drive‐by‐wire vehicle. Copyright © 2008 John Wiley & Sons, Ltd.     

Acidic urine pH is associated with elevated levels of free urinary benzidine and N-acetylbenzidine and urothelial cell DNA adducts in exposed workers

We evaluated the influence of urine pH on the proportion of urinary benzidine (BZ) and N-acetylbenzidine present in the free, unconjugated state and on exfoliated urothelial cell DNA adduct levels in 32 workers exposed to BZ in India. Postworkshift urine pH was inversely correlated with the proportions of BZ (r = -0.78; P < 0.0001) and N-acetylbenzidine (r = -0.67; P < 0.0001) present as free compounds. Furthermore, the average of each subject's pre- and postworkshift urine pH was negatively associated with the predominant urothelial DNA adduct (P = 0.0037, adjusted for urinary BZ and metabolites), which has been shown to cochromatograph with a N-(3'-phosphodeoxyguanosin-8-yl)-N'-acetylbenzidine adduct standard. Controlling for internal dose, individuals with urine pH < 6 had 10-fold higher DNA adduct levels compared to subjects with urine pH > or = 7. As reported previously, polymorphisms in NAT1, NAT2, and GSTM1 had no impact on DNA adduct levels. This is the first study to demonstrate that urine pH has a strong influence on the presence of free urinary aromatic amine compounds and on urothelial cell DNA adduct levels in exposed humans. Because there is evidence that acidic urine has a similar influence on aromatic amines derived from cigarette smoke, urine pH, which is influenced by diet, may be an important susceptibility factor for bladder cancer caused by tobacco in the general population.     

Molecular dissection of native mammalian forebrain NMDA receptors containing the NR1 C2 exon: direct demonstration of NMDA receptors comprising NR1, NR2A, and NR2B subunits within the same complex

The subunit compositions of the NR1 C2 exon-containing N-methyl-D-aspartate (NMDA) receptors of adult mammalian forebrain were determined by using a combination of immunoaffinity chromatography and immunoprecipitation studies with NMDA receptor subunit-specific antibodies. NMDA receptors were solubilised by sodium deoxycholate, pH 9, and purified by anti-NR1 C2 antibody affinity chromatography. The purified receptor subpopulation showed immunoreactivity with anti-NR1 C2, anti-NR1 N1, anti-NR1 C2', anti-NR2A, and anti-NR2B NMDA receptor antibodies. The NR1 C2-receptor subpopulation was subjected to immunoprecipitation using anti-NR2B antibodies and the resultant immune pellets analysed by immunoblotting where anti-NR1 C2, anti-NR1 C2', anti-NR2A, and anti-NR2B immunoreactivities were all found. Quantification of the immunoblots showed that 46% of the NR1 C2 immunoreactivity was associated with the NR2B subunit. Of this, 87% (i.e., 40% of total) were NR1 C2/NR2B receptors and 13% (6% of total) were NR1 C2/NR2A/NR2B, thus identifying the triple combination as a minor receptor subset. These results demonstrate directly, for the first time, the coexistence of the NR2A and NR2B subunits in native NMDA receptors. They show the coexistence of two splice forms of the NR1 subunit, i.e., NR1 C2 and NR1 C2', in native receptors and, in addition, they imply an NMDA receptor subpopulation containing four types of NMDA receptor subunit, NR1 C2, NR1 C2', NR2A, and NR2B, which, in accord with molecular size determinations, predicts that the NMDA receptor is at least tetrameric. These results are the first quantitative study of NMDA receptor subtypes and demonstrate molecular heterogeneity for both the NR1 and the NR2 subunits in native forebrain NMDA receptors.     

A neurohormone regulating both methyl farnesoate synthesis and glucose metabolism in a crustacean

In the article a problem of the flow near of elastic surface body whalelike is considered. The opportunity appearance of the flutter on a surface body is shown. Additional capacity, necessary dolphin is designed at navigation in case of occurrence the flutter. It is shown, that this capacity makes about 26% of limiting capacity, output dolphin. Number Relcr = 4,4.10(6) transition to flutter's mode of the flow the body of the dolphin is found. It is discussed evolutionary formed the mechanism of antiflutter stabilization of the body.     

The presence of a dnaK (HSP70) multigene family in members of the orders Planctomycetales and Verrucomicrobiales

Sequences of the dnaK gene, coding for the 70-kDa heat shock protein (HSP70), were determined for six members of the order Planctomycetales, including representatives of three genera, and for the only cultivated member of the order Verrucomicrobiales, Verrucomicrobium spinosum. A fragment of the dnaK gene was amplified from these strains by PCR with oligonucleotide primers targeting regions of the dnaK gene that are conserved at the amino acid level, and the resulting PCR products were cloned into a plasmid vector. Sequence analysis of the cloned dnaK fragments revealed the presence of two different types of dnaK sequence in one of the planctomycete strains, Planctomyces maris, and in V. spinosum. Only one type of dnaK sequence was found for each of the remaining strains. Phylogenetic analysis of the partial sequence data suggested that the majority of planctomycete strains, including one of the Planctomyces maris sequences, form a coherent phylogenetic group branching adjacent to other main lines of descent within the domain Bacteria, as has been shown previously by 16S rRNA sequence analysis. One of the two V. spinosum dnaK sequences also appears to constitute a separate lineage within the gram-negative bacteria. Each of the remaining sequences from P. maris and V. spinosum, together with the single sequence obtained from Planctomyces limnophilus, appeared to be unrelated to the other planctomycete sequences and to occupy a position distant from that of other gram-negative bacteria. The phylogenetic diversity of dnaK sequences exhibited by P. maris and V. spinosum was comparable to that found in Synechococcus sp. strain PCC7942 and Escherichia coli, the only other prokaryotes for which a dnaK multigene family has been demonstrated.     

Preliminary animal pharmacokinetics of the parenteral antifungal agent MK-0991 (L-743,872)

MK-0991 (L-743,872) is a potent antifungal agent featuring long half-life pharmacokinetics. The pharmacokinetics of MK-0991 administered intravenously to mice, rats, rhesus monkeys, and chimpanzees is presented. Unique to MK-0991 is its consistent cross-species performance. The range of values for the pharmacokinetic parameters were as follows: clearance, 0.26 to 0.51 ml/min/kg; half-life, 5.2 to 7.6 h; and distributive volume, 0.11 to 0.27 liters/kg. The level of protein binding of MK-0991 was determined to be 96% in mouse and human serum. The compound exhibited high affinities for human serum albumin and at least two lipid components. The rationale for the selection of MK-0991 as a drug development candidate was based on its two- to threefold superior pharmacokinetic performance in chimpanzees over the performance of an otherwise equivalent analog, L-733,560. Once-daily dosing for MK-0991 is indicated by a graphical comparison of levels in the circulations of chimpanzees and mice. In a study of the pharmacokinetics of MK-0991 in mouse tissue, the organs were assayed following intraperitoneal administration. The area under the concentration-versus-time curves (AUC) segregated the tissues into three exposure categories relative to plasma. The tissues with greater exposure than that for plasma were liver (16 times), kidney (3 times), and large intestine (2 times). The exposure for small intestine, lung, and spleen were equivalent to that for plasma. Organs with lower levels of exposure were the heart (0.3 times that for plasma), thigh (0.2 times), and brain (0.06 times). Kinetically, drug was cleared more slowly from all tissues than from plasma, indicating that terminal-phase equilibrium had not been achieved by 24 h. Thus, some measure of accumulation is predicted for all tissues. Single daily doses of MK-0991 should provide adequate systemic levels of fungicidal activity as a result of its long half-life pharmacokinetics, wide distribution, and slowly accumulating concentrations in tissue.     

Image-guided endoscopic surgery: results of accuracy and performance in a multicenter clinical study using an electromagnetic tracking system

Image-guided surgery has recently been described in the literature as a useful technology for improved functional endoscopic sinus surgery localization. Image-guided surgery yields accurate knowledge of the surgical field boundaries, allowing safer and more thorough sinus surgery. We have previously reviewed our initial experience with The InstaTrak System. This article presents a multicenter clinical study (n=55) that assesses the system's capability for localizing structures in critical surgical sites. The purpose of this paper is to present quantitative data on accuracy and performance. We describe several new advances including an automated registration technique that eliminates the redundant computed tomography scan, compensation for head movement, and the ability to use interchangeable instruments.     

Learning disabled and normal college students' performance on reaction time and speeded classification tasks.

Examined the efficiency with which 24 learning-disabled (LD [mean Wechsler Adult Intelligence Scale—Revised Full-Scale IQ 105.04]) and 24 non-learning-disabled (NLD) college students performed basic cognitive-processing tasks. A simple visual reaction time (RT) and 3 speeded classification tasks were used. Results indicate that the LD Ss were slower and more variable on the speeded classification tasks than were the NLD Ss; however, the 2 groups did not differ on the simple visual RT task. Findings suggest that the deficits in higher cognitive processing found in younger LD children persist into early adulthood. It is argued that this failure to automatize very basic subskills may relate to central nervous system (CNS) dysfunction among the LD. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)