Design and analysis of a robust real-time engine control network

Increasing numbers of automotive control systems are being designed as distributed systems, with critical functions linked by electronic communications. This includes X-by-wire systems, which seek to replace mechanical or hydraulic linkages with electrical or communications links. These systems raise a number of new challenges: Safety is a function of the whole system rather than any one system feature. Thus, safety analysis and understanding must occur at the (complex) system level. A robust design process is essential to ensure that complex system issues and critical analysis occur at the right development stage and cover all appropriate parts of the system. This article provides a case study of a development project to show how these and other issues can be addressed. We describe the development of a communications network for a safety-related engine application that consists of a central electronic control unit (ECU) and a number of distributed actuators that are controlled via the network. We apply several techniques, such as hazard and scheduling analysis, to resolve safety and reliability issues     

Nonlinear adaptive filtering of stimulus artifact

Noninvasive measurements of somatosensory evoked potentials have both clinical and research applications. The electrical artifact which results from the stimulus is an interference which can distort the evoked signal, and introduce errors in response onset timing estimation. Given that this interference is synchronous with the evoked signal, it cannot be reduced by the conventional technique of ensemble averaging. The technique of adaptive noise cancelling has potential in this regard however, and has been used effectively in other similar problems. An adaptive noise cancelling filter which uses a neural network as the adaptive element is investigated in this application. The filter is implemented and performance determined in the cancelling of artifact for in vivo measurements on the median nerve. A technique of segmented neural network training is proposed in which the network is trained on that segment of the record time window which does not contain the evoked signal. The neural network is found to generalize well from this training to include the segment of the window containing the evoked signal. Both quantitative and qualitative measures show that significant stimulus artifact reduction is achieved.     

Children's attributions of intentions to an invisible agent.

Children ages 3-9 years were informed that an invisible agent (Princess Alice) would help them play a forced-choice game by "telling them, somehow, when they chose the wrong box," whereas a matched control group of children were not given this supernatural prime. On 2 unexpected event trials, an experimenter triggered a simulated unexpected event (i.e., a light turning on/off; a picture falling), and children's behavioral response to these events (i.e., moving their hand to the opposite box) was coded. Results showed a significant Age Group × Experimental Condition interaction; the only children to reliably alter their behavior in response to the unexpected events were the oldest children (M = 7 years 4 months), who were primed with the invisible agent concept. For children's posttest verbal explanations, also, only these children saw the unexpected events as being referential and declarative (e.g., "Princess Alice did it because I chose the wrong box"). Together, these data suggest that children may not regularly begin to see communicative signs as embedded in unexpected events until they are around 7 years of age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Active-edge planar radiation sensors

Many systems in medicine, biology, high-energy physics, and astrophysics require large area radiation sensors. In most of these applications, minimizing the amount of dead area or dead material is crucial. We have developed a new type of silicon radiation sensor in which the device is active to within a few microns of the mechanical edge. Their perimeter is made by a plasma etcher rather than a diamond saw. Their edges can be defined and also passivated by growing, in an intermediate step, a field oxide on the side surfaces. In this paper, the basic architecture and results from a synchrotron beam test are presented.     

Some considerations on the reliability and validity of the Alcohol Expectancy Questionnaire for Adolescents.

Reviews the material presented in the S. A. Brown et al (see record 1988-28300-001) report on the reliability and validity of the Alcohol Expectancy Questionnaire for Adolescents (AEQ-A). Data are presented that suggest that the reliability and validity of the AEQ-A remain to be fully established. A preliminary outline of a potential theoretical direction is provided that applies Rotter's Social Learning Theory (J. B. Rotter, 1954 and 1982) as a framework for future work with alcohol-related expectancies and other cognitive-behavioral research on alcohol. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pathogenic mechanisms in the rheumatoid nodule: comparison of proinflammatory cytokine production and cell adhesion molecule expression in rheumatoid nodules and synovial membranes from the same patient

OBJECTIVE: To investigate the production of proinflammatory cytokines and expression of cell adhesion molecules in the rheumatoid nodule. METHODS: Cytokine content (tumor necrosis factor alpha [TNFalpha], interleukin-1beta [IL-1beta], and IL-1 receptor antagonist [IL-1Ra]), at the messenger RNA (mRNA) and protein levels, and cell adhesion molecule expression were studied in 16 rheumatoid nodules and 6 synovial membranes. RESULTS: Macrophages in the rheumatoid nodules contained TNFalpha, IL-1beta, and IL-1Ra mRNA and protein, particularly in perivascular cells of the stroma and in the palisading layer. All cell adhesion molecules studied were expressed in both the rheumatoid nodules and synovial membranes, with increased expression of E-selectin in the rheumatoid nodule compared with the synovial membrane, and with the absence of vascular cell adhesion molecule 1 expression on cells of the palisading layer in the rheumatoid nodule. CONCLUSION: The presence of similar proinflammatory cytokines and cell adhesion molecules in the rheumatoid nodule and synovial membrane suggests that similar pathogenic processes result in the chronic inflammation and tissue destruction in these lesions.     

A mixed disulfide bond in bacterial glutathione transferase: functional and evolutionary implications

BACKGROUND: Glutathione S-transferases (GSTs) are a multifunctional group of enzymes, widely distributed in aerobic organisms, that have a critical role in the cellular detoxification process. Unlike their mammalian counterparts, bacterial GSTs often catalyze quite specific reactions, suggesting that their roles in bacteria might be different. The GST from Proteus mirabilis (PmGST B1-1) is known to bind certain antibiotics tightly and reduce the antimicrobial activity of beta-lactam drugs. Hence, bacterial GSTs may play a part in bacterial resistance towards antibiotics and are the subject of intense interest. RESULTS: Here we present the structure of a bacterial GST, PmGST B1-1, which has been determined from two different crystal forms. The enzyme adopts the canonical GST fold although it shares less than 20% sequence identity with GSTs from higher organisms. The most surprising aspect of the structure is the observation that the substrate, glutathione, is covalently bound to Cys 10 of the enzyme. In addition, the highly structurally conserved N-terminal domain is found to have an additional beta strand. CONCLUSIONS: The crystal structure of PmGST B1-1 has highlighted the importance of a cysteine residue in the catalytic cycle. Sequence analyses suggest that a number of other GSTs share this property, leading us to propose a new class of GSTs - the beta class. The data suggest that the in vivo role of the beta class GSTs could be as metabolic or redox enzymes rather than conjugating enzymes. Compelling evidence is presented that the theta class of GSTs evolved from an ancestral member of the thioredoxin superfamily.     

Low-frequency characteristics of thin-film multijunction thermalvoltage converters

Low-frequency errors of thin-film multijunction thermal voltage converters are estimated using a simple model based on easily measured parameters. The model predictions are verified by measuring the converter's frequency characteristic using a digitally synthesized source     

Matrilineal inheritance of complex I dysfunction in a multigenerational Parkinson's disease family

Recent data suggesting complex I dysfunction in Parkinson's disease (PD) arises from mitochondrial DNA (mtDNA) mutation does not conclusively answer whether the responsible genetic lesion is inherited (primary) or somatic (secondary). To address this question, we identified a family in which multiple members over three generations are affected with PD through exclusively maternal lines. Cytoplasmic hybrids (cybrids) were created for 15 family members over two generations by transferring each individual's mtDNA to mtDNA-depleted human neuroblastoma cells. Eight of the 15 cybrid lines contained mtDNA obtained from maternally descended family members and seven contained mtDNA from paternally descended family members. After 6 weeks of culture, cybrid cell lines were assayed for complex I activity and oxidative stress, and mitochondrial morphology was analyzed by electron microscopy. Compared with the cybrid lines containing mtDNA from paternal descendants, cybrid lines containing mtDNA from maternal descendants had lower complex I activity, increased reactive oxygen species production, increased radical scavenging enzyme activities, and more abnormal mitochondrial morphologic features. These findings were present in cybrid lines containing mtDNA from maternal descendants with PD as well as in currently asymptomatic young maternal descendants, and support a precedent for inherited mtDNA mutation in some persons with PD.