The role of regulatory light chains (RLCs) in cardiac muscle function has been elucidated progressively over the past decade. The RLCs are among the earliest expressed markers during cardiogenesis and persist through adulthood. Failing hearts have shown reduced RLC phosphorylation levels and that restoring baseline levels of RLC phosphorylation is necessary for generating optimal force of muscle contraction. The signalling mechanisms triggering changes in RLC phosphorylation levels during disease progression remain elusive. Uncovering this information may provide insights for better management of heart failure patients. Given the cardiac chamber-specific expression of RLC isoforms, ventricular RLCs have facilitated the identification of mature ventricular cardiomyocytes, opening up possibilities of regenerative medicine. This review consolidates the standing of RLCs in cardiac development and disease and highlights knowledge gaps and potential therapeutic advancements in targeting RLCs. 相似文献
Based on the experience of the gasifier users on the efforts and energy for wood chip preparation in a typical gasifier, we have embarked on the development of a gasifier suitable to work with long stick woody biomass as the feed materials. In the context of the impact of gasifiers, as decentralized energy delivery devices such an approach, it is hoped, would be an attractive option in rural areas both in domestic and industrial sectors. In the present paper in the gasifier operation, there is a fixed quantity of char that is combusted to gasify a fixed amount of wood, and the gasifier does not operate in a steady state manner. In this present work, focus is made on the development of a gasifier using long sticks of wood as feed materials. With this concept, a 10 kW thermal output power gasifier is designed and constructed. The gas and airflows can be converted to the air/fuel ratio, the most important aspect of gasifier operation. The air/fuel ratio shows operation in a combustion mode at start up, a gasification mode for the middle part of the run and a charcoal gasification mode at the end of the run. Since the interest here is exploring and validating of this concept, a bottom lit updraft gasifier is designed mainly to look at the gas yield and other favourable factors and to use this gas so obtained for thermal applications. The rate of feed was between 9 and 10 kg/h and continuous operation for 5 h was made in a couple of runs to study the performance. In this paper we report the salient features of our efforts and results, yielding a gasifier efficiency of 73%. 相似文献
Room temperature fracture toughness along with compressive deformation behavior at both room and high temperatures (900 °C, 1000 °C and 1100 °C) has been evaluated for ternary or quaternary hypoeutectic (Nb–12Si–5Mo and Nb–12Si–5Mo–20Ti) and hypereutectic (Nb–19Si–5Mo and Nb–19Si–5Mo–20Ti) Nb-silicide based intermetallic alloys to examine the effects of composition, microstructure, and annealing (100 hours at 1500 °C). On Ti-addition and annealing, the fracture toughness has increased by up to ~ 75 and ~ 63 pct, respectively with ~ 14 MPa√m being recorded for the annealed Nb–12Si–5Mo–20Ti alloy. Toughening is ascribed to formation of non-lamellar eutectic with coarse Nbss, which contributes to crack path tortuosity by bridging, arrest, branching and deflection of cracks. The room temperature compressive strengths are found as ~ 2200 to 2400 MPa for as-cast alloys, and ~ 1700 to 2000 MPa after annealing with the strength reduction being higher for the hypoeutectic compositions due to larger Nbss content. Further, the compressive ductility has varied from 5.7 to 6.5 pct. The fracture surfaces obtained from room temperature compression tests have revealed evidence of brittle failure with cleavage facets and river patterns in Nbss along with its decohesion at non-lamellar eutectic. The compressive yield stress decreases with increase in test temperature, with the hypoeutectic alloys exhibiting higher strength retention indicating the predominant role of solid solution strengthening of Nbss. The flow curves obtained from high temperature compression tests show initial work hardening, followed by a steady state regime indicating dynamic recovery involving the formation of low angle grain boundaries in the Nbss, as confirmed by electron backscattered diffraction of the annealed Nb–12Si–5Mo alloy compression tested at 1100 °C.
A computer vision-based system using images from an airborne aircraft can increase flight safety by aiding the pilot to detect obstacles in the flight path so as to avoid mid-air collisions. Such a system fits naturally with the development of an external vision system proposed by NASA for use in high-speed civil transport aircraft with limited cockpit visibility. The detection techniques should provide high detection probability for obstacles that can vary from subpixels to a few pixels in size, while maintaining a low false alarm probability in the presence of noise and severe background clutter. Furthermore, the detection algorithms must be able to report such obstacles in a timely fashion, imposing severe constraints on their execution time. For this purpose, we have implemented a number of algorithms to detect airborne obstacles using image sequences obtained from a camera mounted on an aircraft. This paper describes the methodology used for characterizing the performance of the dynamic programming obstacle detection algorithm and its special cases. The experimental results were obtained using several types of image sequences, with simulated and real backgrounds. The approximate performance of the algorithm is also theoretically derived using principles of statistical analysis in terms of the signal-to-noise ration (SNR) required for the probabilities of false alarms and misdetections to be lower than prespecified values. The theoretical and experimental performance are compared in terms of the required SNR. 相似文献
Prediction markets, also known as information or decision markets, are designed to forecast future events or trends. Internet-based prediction markets can easily aggregate the insights of an unlimited number of potentially knowledgeable people asynchronously. The Tech Buzz Game - a joint venture between Yahoo! Research Labs and O'Reilly Media - is a fantasy prediction market launched in March 2005 at the O'Reilly Emerging Technology (ETech) Conference. The game consists of multiple sub-markets that pit a handful of rival technologies, each represented by a stock, against one another. The game's object is to anticipate future search buzz and buy and sell stocks accordingly. Thus, a player who believes BitTorrent stock is undervalued might buy shares, while a player who thinks BitTorrent is overpriced might sell the stock or instead purchase shares in a competing peer-to-peer technology. The Tech Buzz Game serves two key research-oriented goals. One is to evaluate the power of prediction markets to forecast high-tech trends. The other goal of the Tech Buzz Game is to field test the dynamic pari-mutuel market, a Yahoo! Research Labs trading mechanism designed to price and allocate shares. 相似文献
This correspondence presents a system for detecting dimension sets in engineering drawings that are drawn to ANSI drafting standards. A new rule-based text/graphics separation algorithm and a model-based procedure for detecting arrowheads in any orientation have been developed. Arrowhead tracking and search methods are used to extract leaders, tails, and witness lines from segmented images containing only graphics. Text blocks and feature control frames extracted from the segmented images are than associated with their corresponding leaders to obtain complete dimension sets. Experimental results are presented 相似文献
Many eukaryotic proteins are modified by Asn-linked (N-linked) glycosylation. The number and position of oligosaccharides added to a protein by the enzyme oligosaccharyltransferase can influence its expression and function. N-Linked glycosylation usually occurs at Asn residues in Asn-X-Ser/Thr sequons where X not equal Pro. However, many Asn-X-Ser/Thr sequons are not glycosylated or are glycosylated inefficiently. Inefficient glycosylation at one or more Asn-X-Ser/Thr sequons in a protein results in the production of heterogeneous glycoprotein products. These glycoforms may differ from one another in their level of expression, stability, antigenicity, or function. The signals which control the efficiency of N-linked glycosylation at individual Asn residues have not been fully defined. In this report, we use a site-directed mutagenesis approach to investigate the influence of the amino acid at the position following a sequon (the Y position, Asn-X-Ser/Thr-Y). Variants of rabies virus glycoprotein containing a single Asn-X-Ser/Thr sequon at Asn37 were generated. Variants were designed with each of the twenty common amino acids at the Y position, with either Ser or Thr at the hydroxy (Ser/Thr) position. The core glycosylation efficiency of each variant was quantified using a cell-free translation/glycosylation system. These studies reveal that the amino acid at the Y position is an important determinant of core glycosylation efficiency. 相似文献