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Sensing System (sensing + system)
Kinds of Sensing System Selected AbstractsConsistency of modelled and observed temperature trends in the tropical troposphereINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 13 2008B. D. Santer Abstract A recent report of the U.S. Climate Change Science Program (CCSP) identified a ,potentially serious inconsistency' between modelled and observed trends in tropical lapse rates (Karl et al., 2006). Early versions of satellite and radiosonde datasets suggested that the tropical surface had warmed more than the troposphere, while climate models consistently showed tropospheric amplification of surface warming in response to human-caused increases in well-mixed greenhouse gases (GHGs). We revisit such comparisons here using new observational estimates of surface and tropospheric temperature changes. We find that there is no longer a serious discrepancy between modelled and observed trends in tropical lapse rates. This emerging reconciliation of models and observations has two primary explanations. First, because of changes in the treatment of buoy and satellite information, new surface temperature datasets yield slightly reduced tropical warming relative to earlier versions. Second, recently developed satellite and radiosonde datasets show larger warming of the tropical lower troposphere. In the case of a new satellite dataset from Remote Sensing Systems (RSS), enhanced warming is due to an improved procedure of adjusting for inter-satellite biases. When the RSS-derived tropospheric temperature trend is compared with four different observed estimates of surface temperature change, the surface warming is invariably amplified in the tropical troposphere, consistent with model results. Even if we use data from a second satellite dataset with smaller tropospheric warming than in RSS, observed tropical lapse rate trends are not significantly different from those in all other model simulations. Our results contradict a recent claim that all simulated temperature trends in the tropical troposphere and in tropical lapse rates are inconsistent with observations. This claim was based on use of older radiosonde and satellite datasets, and on two methodological errors: the neglect of observational trend uncertainties introduced by interannual climate variability, and application of an inappropriate statistical ,consistency test'. Copyright © 2008 Royal Meteorological Society [source] Putative Nitrogen Sensing Systems in Higher PlantsJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 8 2006Hon-Ming Lam Abstract Nitrogen (N) metabolism is essential for the biosynthesis of vital biomolecules. N status thus exerts profound effects on plant growth and development, and must be closely monitored. In bacteria and fungi, a few sophisticated N sensing systems have been extensively studied. In animals, the ability to receive amino acid signals has evolved to become an integral part of the nervous coordination system. In this review, we will summarize recent developments in the search for putative N sensing systems in higher plants based on homologous systems in bacteria, fungi, and animals. Apparently, although plants have separated and diversified from other organisms during the evolution process, striking similarities can be found in their N sensing systems compared with those of their counterparts; however, our understanding of these systems is still incomplete. Significant modifications of the N sensing systems (including cross-talk with other signal transduction pathways) in higher plants may be a strategy of adaptation to their unique mode of life. (Managing editor: Ping He) [source] Development of an Accurate Positioning System Using Low-Cost L1 GPS ReceiversCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 4 2006Masayuki Saeki This system employs an inexpensive L1 GPS receiver and a small patch antenna. As these devices are very inexpensive and small, they can be attached to an array of sensor nodes of a wireless network sensing system. In the present study, we first develop a program that can be used to estimate the relative positions of receivers and evaluate its performance. Next, a number of experiments were conducted to assess the performance of the inexpensive L1 GPS receiver with a patch antenna. Compared to the results obtained using a sophisticated antenna, the present measurement system, which uses a patch antenna, is less accurate. However, the present system achieves an accuracy of 1,2 cm. This system can be used as a localization system for the sensor nodes or, because of its accuracy, as a displacement monitoring system. [source] The natural furanone (5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone disrupts quorum sensing-regulated gene expression in Vibrio harveyi by decreasing the DNA-binding activity of the transcriptional regulator protein luxRENVIRONMENTAL MICROBIOLOGY, Issue 10 2007Tom Defoirdt Summary This study aimed at getting a deeper insight in the molecular mechanism by which the natural furanone (5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone disrupts quorum sensing in Vibrio harveyi. Bioluminescence experiments with signal molecule receptor double mutants revealed that the furanone blocks all three channels of the V. harveyi quorum sensing system. In further experiments using mutants with mutations in the quorum sensing signal transduction pathway, the compound was found to block quorum sensing-regulated bioluminescence by interacting with a component located downstream of the Hfq protein. Furthermore, reverse transcriptase real-time polymerase chain reaction with specific primers showed that there was no effect of the furanone on luxRVh mRNA levels in wild-type V. harveyi cells. In contrast, mobility shift assays showed that in the presence of the furanone, significantly lower levels of the LuxRVh response regulator protein were able to bind to its target promoter sequences in wild-type V. harveyi. Finally, tests with purified LuxRVh protein also showed less shifts with furanone-treated LuxRVh, whereas the LuxRVh concentration was found not to be altered by the furanone (as determined by SDS-PAGE). Therefore, our data indicate that the furanone blocks quorum sensing in V. harveyi by rendering the quorum sensing master regulator protein LuxRVh unable to bind to the promoter sequences of quorum sensing-regulated genes. [source] Gold-Nanocluster-Based Fluorescent Sensors for Highly Sensitive and Selective Detection of Cyanide in WaterADVANCED FUNCTIONAL MATERIALS, Issue 6 2010Yanlan Liu Abstract A novel, gold-nanocluster-based fluorescent sensor for cyanide in aqueous solution, which is based on the cyanide etching-induced fluorescence quenching of gold nanoclusters, is reported. In addition to offering high selectivity due to the unique Elsner reaction between cyanide and the gold atoms of gold nanoclusters, this facile, environmentally friendly and cost-effective method provides high sensitivity. With this sensor, the lowest concentration to quantify cyanide ions could be down to 200,×,10,9,M, which is approximately 14 times lower than the maximum level (2.7,×,10,6,M) of cyanide in drinking water permitted by the World Health Organization (WHO). Furthermore, several real water samples spiked with cyanide, including local groundwater, tap water, pond water, and lake water, are analyzed using the sensing system, and experimental results show that this fluorescent sensor exhibits excellent recoveries (over 93%). This gold-nanocluster-based fluorescent sensor could find applications in highly sensitive and selective detection of cyanide in food, soil, water, and biological samples. [source] Conjugated Polymers Combined with a Molecular Beacon for Label-Free and Self-Signal-Amplifying DNA MicroarraysADVANCED FUNCTIONAL MATERIALS, Issue 20 2009Kangwon Lee Abstract A conjugated polymer (CP) and molecular-beacon-based solid-state DNA sensing system is developed to achieve sensitive, label-free detection. A novel conjugated poly(oxadiazole) derivative exhibiting amine and thiol functional groups (POX-SH) is developed for unique chemical and photochemical stability and convenient solid-state on-chip DNA synthesis. POX-SH is soluble in most nonpolar organic solvents and exhibits intense blue fluorescence. POX-SH is covalently immobilized onto a maleimido-functionalized glass slide by means of its thiol group. Molecular beacons having a fluorescent dye or quencher molecule as the fluorescence resonance energy transfer (FRET) acceptor are synthesized on the immobilized POX-SH layer through direct on-chip oligonucleotide synthesis using the amine side chain of POX-SH. Selective hybridization of the molecular beacon probes with the target DNA sequence opens up the molecular beacon probes and affects the FRET between POX-SH and the dye or quencher, producing a sensitive and label-free fluorescence sensory signal. Various molecular design parameters, such as the size of the stem and loop of the molecular beacon, the choice of dye, and the number of quencher molecules are systematically controlled, and their effects on the sensitivity and selectivity are investigated. [source] Interference with the quorum sensing systems in a Vibrio harveyi strain alters the growth rate of gnotobiotically cultured rotifer Brachionus plicatilisJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2007N.T.N. Tinh Abstract Aims:, To evaluate the effect of Vibrio harveyi strains on the growth rate of the gnotobiotically cultured rotifer Brachionus plicatilis, and to establish whether quorum sensing is involved in the observed phenomena. Methods and Results:, Gnotobiotic B. plicatilis sensu strictu, obtained by hatching glutaraldehyde-treated amictic eggs, were used as test organisms. Challenge tests were performed with 11 V. harveyi strains and different quorum sensing mutants derived from the V. harveyi BB120 strain. Brominated furanone [(5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone] as a quorum sensing inhibitor was tested in Brachionus challenge tests. Some V. harveyi strains, such as strain BB120, had a significantly negative effect on the Brachionus growth rate. In the challenge test with MM77, an isogenic strain of BB120 in which the two autoinducers (HAI-1 and AI-2) are both inactivated, no negative effect was observed. The effect of single mutants was the same as that observed in the BB120 strain. This indicates that both systems are responsible for the growth-retarding (GR) effect of the BB120 strain towards Brachionus. Moreover, the addition of an exogenous source of HAI-1 or AI-2 could restore the GR effect in the HAI-1 and AI-2 nonproducing mutant MM77. The addition of brominated furanone at a concentration of 2·5 mg l,1 could neutralize the GR effect of some strains such as BB120 and VH-014. Conclusions:, Two quorum sensing systems in V. harveyi strain BB120 (namely HAI-1 and AI-2-mediated) are necessary for its GR effect on B. plicatilis. With some other V. harveyi strains, however, growth inhibition towards Brachionus does not seem to be related to quorum sensing. Significance and Impact of the Study:, Interference with the quorum sensing system might help to counteract the GR effect of some V. harveyi strains on Brachionus. However, further studies are needed to demonstrate the positive effect of halogenated furanone in nongnotobiotic Brachionus cultures and eventually, in other segments of the aquaculture industry. [source] Application of a Service Climbing Robot with Motion Planning and Visual SensingJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 4 2003Jian Zhu This paper describes an application of a service climbing robot aimed to clean the glass wall of high-rise buildings. The robot utilizes suction cups to adhere to the glass and moves with a translational mechanism to follow a predetermined path in cleaning the whole glass surface. By a flexible waist, the robot can adjust its posture. The robot has the ability to cross the window frame to clean different sections of the glass wall. A visual sensing system, composed of an omnidirectional CCD camera and two laser diodes, enables the robot to measure its orientation and the distance between the robot and the window frame. The real-time applications and some experimental results demonstrate the effectiveness of the developed system. © 2003 Wiley Periodicals, Inc. [source] A Novel In situ Recognition of Misalignment between Mating Parts in Robotic Assembly ProcessesJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11 2002W. S. Kim A visual sensing system is utilized mainly to estimate the misalignment between mating parts, the recognition of which is the integral part of any assembly process. The recognition, however, requires the information on the state of the misalignment that includes the shapes of parts in mating motion and instantaneous relative position and angular orientation between mating parts. Normally, this information has been given in advance by an operator to facilitate assembly action. Therefore, in order to recognize the assembly state in sequence without intervention of an operator, it requires an effective sensing system and algorithm capable of working well even without a priori information on part shape and location. In this paper, we propose a novel system that can assemble parts under such uncertain environments. The system, composed of an omnidirectional sensing module and a recognition module, is capable of acquiring information on the sequential state of parts assembly motion from which instantaneous, relative location and orientation between the mating parts can be determined. Since the system does not utilize a priori knowledge on the shape of mating parts, it greatly reduces the degree of human intervention, thus increasing autonomy and flexibility. To evaluate the performance of the proposed system, a series of assembly experiments are performed. The results show that the proposed system, indeed, demonstrates effectiveness of vision guided assembly action. © 2002 Wiley Periodicals, Inc. [source] FOOD HARDNESS AND FRACTURABILITY ASSESSMENT BY AN ELECTRONIC SENSING SYSTEM1JOURNAL OF TEXTURE STUDIES, Issue 2 2002YANKUN PENG ABSTRACT Two texture properties of food, hardness and fracturability, were studied by an electronic sensing system (ESS) with 29 cereal-based foods that represented a range of textures. Three electrodes were used with one located on the cheekbone, one on the lower jaw bone, and the other one, a ground, on the ear lobe. Total energy, peak energy, and Fourier power of the first bite ESS signals were analyzed. The Fourier power of the muscle motion in biting was highly correlated to the muscle motion total energy. Sensory hardness and fracturability were correlated with the first bite ESS total energy and first bite ESS Fourier power (r = 0.82 and 0.74). [source] PBG Fibers for Gas Concentration MeasurementPLASMA PROCESSES AND POLYMERS, Issue 7-8 2007Joanna Paw Abstract The idea of a high-sensitivity gas concentration measuring system based on a photonic bandgap fiber (PBG fiber) is studied. Several types of PBG fibers of various parameters have been designed. Core diameters range from 10.9 to 26.25 µm. The capillary gas flow rate within the fiber has been simulated and measured. The attenuation of newly produced fibers is investigated and the concentration of ammonia gas is measured using a proposed sensing system. A new method for cutting the fiber using an Ar ion beam in a vacuumed chamber is tested to obtain the required angle of the fiber's end, and to avoid the destruction of the cladding structure. [source] Effects of muscle type on beef taste-traits assessed by an electric sensing systemANIMAL SCIENCE JOURNAL, Issue 5 2010Koichi CHIKUNI ABSTRACT To assess the role of muscle fiber type in beef taste-traits, we analyzed cooked meats from bovine masseter, diaphragm, psoas major, longissimus thoracis, and semitendinosus muscles with an electric taste sensing system (INSENT SA402B). The system is composed of five taste sensors of polymer membranes fixing different lipids. The sensors, CT0, CA0, AAE, C00 and AE1 are designed to respond to the individual tastes of salty, sour, umami, bitter and astringent, respectively. The system found significant differences in the converted outputs of CA0 (cvCA0), C00 (cvC00) and AE1 (cvAE1) among the bovine muscles. The slow-type muscles (masseter and diaphragm) showed lower cvCA0, higher cvC00, and higher cvAE1 than did the fast-type muscles (psoas major, longissimus thoracis, and semitendinosus). Lactic acid content was different among muscle types and was highly related to the cvCA0 output and pH. carbonyl compounds and free fatty acids were higher in the slow-type muscles. Free fatty acids were major components causing the difference in the C00 output among the muscle types. Iron content was also different among the muscle types and related to the cvC00 and cvAE1 outputs. These results suggested that the muscle fiber type affects the beef taste characteristics. [source] Recent advances in treatment of youth with Type 1 diabetes: better care through technologyDIABETIC MEDICINE, Issue 11 2001W. V. Tamborlane Abstract While treatment of Type 1 diabetes mellitus (T1DM) in children and adolescents is especially difficult, recent technological advances have provided new therapeutic options to clinicians and patients. The urgency to achieve strict diabetes control and the introduction of new and improved insulin pumps have been accompanied by a marked increase in use of continuous subcutaneous insulin infusion (CSII) therapy in youth with diabetes. Results of clinical outcome studies indicate that CSII provides a safe and effective alternative to multiple daily injection (MDI) therapy, even when employed in a regular clinic setting in a large number of children. The safety and efficacy of CSII is further enhanced by the introduction of lispro and aspart insulin. The sharper peaks and shorter duration of action of these very rapid-acting insulin analogues provides a means to achieve better control of post-prandial hyperglycaemia with less late post-prandial and nocturnal hypoglycaemia. Glargine insulin, a soluble and essentially peakless long-acting insulin analogue, may provide a better basal insulin for MDI regimens, but there are limited published data with this agent in children with T1DM. A number of systems for pulmonary delivery of insulin are in development and preliminary results of Phase III studies have been promising. Like CSII, inhaled insulin allows the child to take bolus insulin doses before each meal without having to take a premeal injection. A major obstacle to effective treatment is that self-monitoring of three to four blood glucose levels a day often misses the marked glycaemic excursions that characterize T1DM in young patients. On the other hand, new continuous glucose sensing systems provide a wealth of data that can be used to optimize basal and bolus therapy, regardless of how insulin is administered. Even more important, we may finally be at the threshold of development of a practically applicable artificial pancreas. Diabet. Med. 18, 864,870 (2001) [source] Algorithms for time synchronization of wireless structural monitoring sensorsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 6 2005Ying Lei Abstract Dense networks of wireless structural health monitoring systems can effectively remove the disadvantages associated with current wire-based sparse sensing systems. However, recorded data sets may have relative time-delays due to interference in radio transmission or inherent internal sensor clock errors. For structural system identification and damage detection purposes, sensor data require that they are time synchronized. The need for time synchronization of sensor data is illustrated through a series of tests on asynchronous data sets. Results from the identification of structural modal parameters show that frequencies and damping ratios are not influenced by the asynchronous data; however, the error in identifying structural mode shapes can be significant. The results from these tests are summarized in Appendix A. The objective of this paper is to present algorithms for measurement data synchronization. Two algorithms are proposed for this purpose. The first algorithm is applicable when the input signal to a structure can be measured. The time-delay between an output measurement and the input is identified based on an ARX (auto-regressive model with exogenous input) model for the input,output pair recordings. The second algorithm can be used for a structure subject to ambient excitation, where the excitation cannot be measured. An ARMAV (auto-regressive moving average vector) model is constructed from two output signals and the time-delay between them is evaluated. The proposed algorithms are verified with simulation data and recorded seismic response data from multi-story buildings. The influence of noise on the time-delay estimates is also assessed. Copyright © 2004 John Wiley & Sons, Ltd. [source] Application of Nanoparticles in Electrochemical Sensors and BiosensorsELECTROANALYSIS, Issue 4 2006Xiliang Luo Abstract The unique chemical and physical properties of nanoparticles make them extremely suitable for designing new and improved sensing devices, especially electrochemical sensors and biosensors. Many kinds of nanoparticles, such as metal, oxide and semiconductor nanoparticles have been used for constructing electrochemical sensors and biosensors, and these nanoparticles play different roles in different sensing systems. The important functions provided by nanoparticles include the immobilization of biomolecules, the catalysis of electrochemical reactions, the enhancement of electron transfer between electrode surfaces and proteins, labeling of biomolecules and even acting as reactant. This minireview addresses recent advances in nanoparticle-based electrochemical sensors and biosensors, and summarizes the main functions of nanoparticles in these sensor systems. [source] Quorum sensing: the power of cooperation in the world of PseudomonasENVIRONMENTAL MICROBIOLOGY, Issue 4 2005Mario Juhas Summary Work over the past few years has provided evidence that quorum sensing is a generic regulatory mechanism that allows bacteria to launch a unified, coordinated response in a population density-dependent manner to accomplish tasks which would be difficult, if not impossible, to achieve for a single bacterial cell. Quorum sensing systems are widespread among pseudomonads and the one of the human opportunistic pathogen Pseudomonas aeruginosa belongs to the most extensively studied cell-to-cell communication systems. In this organism, quorum sensing is highly complex and is made up of two interlinked N- acyl homoserine lactone (AHL)-dependent regulatory circuits, which are further modulated by a non-AHL-related signal molecule and numerous regulators acting both at the transcriptional and post-transcriptional level. This genetic complexity may be one of the key elements responsible for the tremendous environmental versatility of P. aeruginosa. Work of the past few years showed that quorum sensing is essential for the expression of a battery of virulence factors as well as for biofilm formation in P. aeruginosa and thus represents an attractive target for the design of novel drugs for the treatment of P. aeruginosa infections. Furthermore, the cell-to-cell communication ability was also demonstrated in a number of additional pseudomonads. [source] Photoluminescence-Based Sensing With Porous Silicon Films, Microparticles, and NanoparticlesADVANCED FUNCTIONAL MATERIALS, Issue 20 2009Michael J. Sailor Abstract Here, chemical sensors made from porous Si are reviewed, with an emphasis on systems that harness photoluminescence and related energy- and charge-transfer mechanisms available to porous Si-derived nanocrystallites. Quenching of luminescence by molecular adsorbates involves the harvesting of energy from a delocalized nanostructure that can be much larger than the molecule being sensed, providing a means to amplify the sensory event. The interaction of chemical species on the surface of porous Si can exert a pronounced influence on this process, and examples of some of the key chemical reactions that modify either the surface or the bulk properties of porous Si are presented. Sensors based on micron-scale and smaller porous Si particles are also discussed. Miniaturization to this size regime enables new applications, including imaging of cancerous tissues, indirect detection of reactive oxygen species (ROS), and controlled drug release. Examples of environmental and in vivo sensing systems enabled by porous Si are provided. [source] Interference with the quorum sensing systems in a Vibrio harveyi strain alters the growth rate of gnotobiotically cultured rotifer Brachionus plicatilisJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2007N.T.N. Tinh Abstract Aims:, To evaluate the effect of Vibrio harveyi strains on the growth rate of the gnotobiotically cultured rotifer Brachionus plicatilis, and to establish whether quorum sensing is involved in the observed phenomena. Methods and Results:, Gnotobiotic B. plicatilis sensu strictu, obtained by hatching glutaraldehyde-treated amictic eggs, were used as test organisms. Challenge tests were performed with 11 V. harveyi strains and different quorum sensing mutants derived from the V. harveyi BB120 strain. Brominated furanone [(5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone] as a quorum sensing inhibitor was tested in Brachionus challenge tests. Some V. harveyi strains, such as strain BB120, had a significantly negative effect on the Brachionus growth rate. In the challenge test with MM77, an isogenic strain of BB120 in which the two autoinducers (HAI-1 and AI-2) are both inactivated, no negative effect was observed. The effect of single mutants was the same as that observed in the BB120 strain. This indicates that both systems are responsible for the growth-retarding (GR) effect of the BB120 strain towards Brachionus. Moreover, the addition of an exogenous source of HAI-1 or AI-2 could restore the GR effect in the HAI-1 and AI-2 nonproducing mutant MM77. The addition of brominated furanone at a concentration of 2·5 mg l,1 could neutralize the GR effect of some strains such as BB120 and VH-014. Conclusions:, Two quorum sensing systems in V. harveyi strain BB120 (namely HAI-1 and AI-2-mediated) are necessary for its GR effect on B. plicatilis. With some other V. harveyi strains, however, growth inhibition towards Brachionus does not seem to be related to quorum sensing. Significance and Impact of the Study:, Interference with the quorum sensing system might help to counteract the GR effect of some V. harveyi strains on Brachionus. However, further studies are needed to demonstrate the positive effect of halogenated furanone in nongnotobiotic Brachionus cultures and eventually, in other segments of the aquaculture industry. [source] Putative Nitrogen Sensing Systems in Higher PlantsJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 8 2006Hon-Ming Lam Abstract Nitrogen (N) metabolism is essential for the biosynthesis of vital biomolecules. N status thus exerts profound effects on plant growth and development, and must be closely monitored. In bacteria and fungi, a few sophisticated N sensing systems have been extensively studied. In animals, the ability to receive amino acid signals has evolved to become an integral part of the nervous coordination system. In this review, we will summarize recent developments in the search for putative N sensing systems in higher plants based on homologous systems in bacteria, fungi, and animals. Apparently, although plants have separated and diversified from other organisms during the evolution process, striking similarities can be found in their N sensing systems compared with those of their counterparts; however, our understanding of these systems is still incomplete. Significant modifications of the N sensing systems (including cross-talk with other signal transduction pathways) in higher plants may be a strategy of adaptation to their unique mode of life. (Managing editor: Ping He) [source] | ||||||||||||||||||||||