Inhibition of feline collateral vessel development following experimental thrombolic occlusion

We compared development of feline hindlimb collateral circulation after acute occlusion of the terminal aorta by ligation, thrombus formation, and formation of a "closed" aortic loop containing thromboplastin. Collateral circulation development was assessed by aortograms, scintillation scans, neurological signs following occlusion, measurement of hindlimb muscle blood flow, and forelimb and hindlimb temperature. In cats in which aortic occlusion was the result of ligation or thromboplastin in the aortic loop, paralysis was not evident. Aortograms and scintillation scans indicated hindlimb blood flow. Both muscle temperature and blood flow data indicated that the return of blood flow was rapid. The 5th lumbar artery appears to be the origin of the collateral vessels. The mid-zone component is a dorsal and ventral vertebral route and an epaxial muscle route. The reentry components are the 6th or 7th lumbar arteries. The collateral vessels arise from preexisting collateral vessels. Of those cats in which aortic occlusion was the result of a thrombus, all exhibited paralysis. Aortograms, scintillation scans, muscle temperature, and hindlimb blood flow data indicated reduced hindlimb blood flow. The results suggest that the thrombus has an inhibitory effect on the development of collateral circulation.     

Olfactory and auditory event-related potentials in Huntington's disease.

The influence of Huntington's disease (HD) on the olfactory event-related potential (OERP), an electrophysiological measure of olfactory information processing, has not been reported to date. In the present study, olfactory and auditory event-related potentials (ERPs) were recorded monopolarly from Fz, Cz, and Pz electrode sites in 8 patients with HD and 8 age- and gender-matched control participants. Results demonstrated that individuals with HD were delayed compared with controls on the P3 component of the OERP (p     

Organic‐polymer thin‐film transistors for active‐matrix flat‐panel displays?

Abstract— Organic‐polymer‐based thin‐film transistors (OP‐TFTs) look very promising for flexible, large‐area, and low‐cost organic electronics. In this paper, we describe devices based on spin‐coated organic polymer that reproducibly exhibit field‐effect mobility values around 5 × 10^?3 cm²/V‐sec. We also address fabrication, performance, and stability issues that are critical for the use of such devices in active‐matrix flat‐panel displays.     

Hypertext: the next maintenance mountain

Hypertext documents are quickly becoming large, complex, and unwieldy. The paper considers whether lessons learned from software maintenance can be applied to the problem. Since software maintenance is a major problem and since hypertext documents share many of the characteristics of software: structure, development process, and economic value, maintaining hypertext documents is also likely to become a major problem requiring immediate action     

Experiences using lightweight formal methods for requirementsmodeling

The paper describes three case studies in the lightweight application of formal methods to requirements modeling for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process to validate the evolving requirements. The results were fed back into the projects to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, formal methods enhanced the existing verification and validation processes by testing key properties of the evolving requirements and helping to identify weaknesses. We conclude that the benefits gained from early modeling of unstable requirements more than outweigh the effort needed to maintain multiple representations     

Organic polymer thin-film transistor photosensors

We present our study of the effects of monochromatic illumination on the electrical performance of organic polymer thin-film transistors (OP-TFTs) and the use of these devices as photosensors. In the case of monochromatic illumination that is strongly absorbed by the polymer, the drain current of a device biased in the OFF-state is significantly increased and the threshold voltage is reduced. Light that is not strongly absorbed by the polymer has little effect on the electrical performance of the OP-TFTs. We explain these effects in terms of the photogeneration of excitons in the polymer channel region of the device. The density of excitons generated in the polymer depends on the energy of the incident photons, as well as on the irradiance level of the incident illumination. The photogenerated excitons subsequently dissociate into electrons and holes. The electrons can be trapped by positively charged states, thereby reducing the threshold voltage, while the photogenerated holes contribute to the excess photocurrent measured at the drain. To demonstrate the possible use of OP-TFTs as photosensors, we also present the responsivity, photosensitivity (signal-to-noise ratio), external quantum efficiency, noise-equivalent power, and specific detectivity of these devices. The dependence of these parameters on the incident photon energy and irradiance level is described.     

Ontology-based approach to Basic Grafcet formalization

In recent years, various proposals have been put forth to formalize the Grafcet graphical language. The objective of this paper is to propose an ontology-based approach to formalize this language. The authors have implemented a semi-coarse grain ontology written in Ontology Web Language and have tested it by including it in an existing educational tool for the teaching of Grafcet language for use in programmable logic controllers.     

Gene Discovery in Gelsemium Highlights Conserved Gene Clusters in Monoterpene Indole Alkaloid Biosynthesis

Genome mining is a routine technique in microbes for discovering biosynthetic pathways. In plants, however, genomic information is not commonly used to identify novel biosynthesis genes. Here, we present the genome of the medicinal plant and oxindole monoterpene indole alkaloid (MIA) producer Gelsemium sempervirens (Gelsemiaceae). A gene cluster from Catharanthus roseus, which is utilized at least six enzymatic steps downstream from the last common intermediate shared between the two plant alkaloid types, is found in G. sempervirens, although the corresponding enzymes act on entirely different substrates. This study provides insights into the common genomic context of MIA pathways and is an important milestone in the further elucidation of the Gelsemium oxindole alkaloid pathway.     

Differential Signaling by Protease-Activated Receptors: Implications for Therapeutic Targeting

Protease-activated receptors (PARs) are a family of four G protein-coupled receptors that exhibit increasingly appreciated differences in signaling and regulation both within and between the receptor class. By nature of their proteolytic self-activation mechanism, PARs have unique processes of receptor activation, “ligand” binding, and desensitization/resensitization. These distinctive aspects have presented both challenges and opportunities in the targeting of PARs for therapeutic benefit—the most notable example of which is inhibition of PAR1 on platelets for the prevention of arterial thrombosis. However, more recent studies have uncovered further distinguishing features of PAR-mediated signaling, revealing mechanisms by which identical proteases elicit distinct effects in the same cell, as well as how distinct proteases produce different cellular consequences via the same receptor. Here we review this differential signaling by PARs, highlight how important distinctions between PAR1 and PAR4 are impacting on the progress of a new class of anti-thrombotic drugs, and discuss how these more recent insights into PAR signaling may present further opportunities for manipulating PAR activation and signaling in the development of novel therapies.