Product monitoring and quantitation of oligosaccharides composition in agar hydrolysates by precolumn labeling HPLC

Since the discovery of multiple bioactivities for agarobiose oligomers, a quantitative method has been in great need to monitor the agarobiose oligomers. This report demonstrates that agarobiose oligomers can be separated with high resolution in HPLC after introducing a-naphthylamine into compounds. Agarobiose oligomers ranged from biose to decaose were isolated by Sephadex column. HPLC analysis indicated that each oliomer could be quantified with good linearity and a low detection limit of 0.1-4 mug/ml. The chromatographic profiles of agaro-oligosaccharides with different hydrolysis modes (hydrochloride, citric acid, solid acid, and hydroxyl radical degradation) showed that agarobiose could be obtained more than 57.8% using solid acid mediated hydrolysis, while hydrochloride acid could degrade agar into a series of agaro-oligosaccharides from biose to decaose. The yield of oligosaccharides was low if hydrolyzed by citric acid. The Fenton degradation can increase the speed of hydrolysis, but the product was complex. (C) 2004 Elsevier B.V. All rights reserved.

Monitoring microbial populations of sulfate-reducing bacteria using an impedimetric immunosensor based on agglutination assay

An impedimetric immunosensor was fabricated for rapid and non-labeled detection of sulfate-reducing bacteria, Desulforibrio caledoiensis (SRB) by immobilizing lectin-Concanavalin A using an agglutination assay. The immobilization of lectin was conducted using amine coupling on the surface of a gold (Au) electrode assembled with 11-Mercaptounclecanoic acid. Electrochemical impedance spectroscopy (EIS) was used to verify the stepwise assembly of the sensor system. The work conditions of the impedimetric immunosensor, such as pH of the buffer solutions and the incubation time of lectin, were optimized. Faradic impedance spectra for charge transfer for the redox probe Fe(CN)(6)(3-/4-) were measured to determine SRB concentrations. The diameter of the Nyquist diagram that is equal to the charge-transfer resistance (RI) increased with increasing SRB concentration. A linear relationship between R-ct and SRB concentration was obtained in SRB concentration range of 1.8 to 1.8 x 10(7) cfu/ml. The variation of the SRB population during the growth process was also monitored using the impedimetric immunosensor. This approach has great potential for simple, low-cost. and time-saving monitoring of microbial populations. (C) 2009 Elsevier B.V. All rights reserved.

Hydrogen permeation behavior and corrosion monitoring atmospheric of steel in cyclic wet-dry environment

Hydrogen permeation of 16Mn steel under a cyclic wet-dry condition was investigated by Devanathan-Stachurski's electrolytic cell with a membrane covered on the exit side by a nickel layer and the weight loss was measured for each wet-dry cycle. The results show that hydrogen permeation current change with different atmospheric environment: distilled water, seawater, and seawater containing 100 ppm H2S. The results show that seawater can induce an increase in the hydrogen permeation current due to the hydrolyzation reaction. And after the increase, equilibrium is reached due to the equilibrium of hydrolyzation reaction effect and the block of the rust layer. On the other hand, H2S contamination also can induce an increase in the maximum hydrogen permeation current due to the hydrolyzation reaction. And H2S contamination delays the time that hydrogen permeation is detected because of the formation of the FeS(1-x) film. The FeS(1-x) film can block the absorption of hydrogen onto the specimen surface. The surface potential change and the pH change of the metal surface control the hydrogen permeation current. And a clear linear correlation exists between the quantities of hydrogen permeated through the 16Mn steel and the weight loss. Based on the linear correlation, we monitored the corrosion rate by monitoring the hydrogen permeation current by a sensor outside. Good coherences were shown between results in laboratory and outside.

Monitoring and simulation of water, heat,and CO2 fluxes in terrestrial ecosystems based on the APEIS-FLUX system

The Integrated Environmental Monitoring (IEM) project, part of the Asia-Pacific Environmental Innovation Strategy (APEIS) project, developed an integrated environmental monitoring system that can be used to detect, monitor, and assess environmental disasters, degradation, and their impacts in the Asia-Pacific region. The system primarily employs data from the moderate resolution imaging spectrometer (MODIS) sensor on the Earth Observation System- (EOS-) Terra/Aqua satellite,as well as those from ground observations at five sites in different ecological systems in China. From the preliminary data analysis on both annual and daily variations of water, heat and CO2 fluxes, we can confirm that this system basically has been working well. The results show that both latent flux and CO2 flux are much greater in the crop field than those in the grassland and the saline desert, whereas the sensible heat flux shows the opposite trend. Different data products from MODIS have very different correspondence, e.g. MODIS-derived land surface temperature has a close correlation with measured ones, but LAI and NPP are quite different from ground measurements, which suggests that the algorithms used to process MODIS data need to be revised by using the local dataset. We are now using the APEIS-FLUX data to develop an integrated model, which can simulate the regional water,heat, and carbon fluxes. Finally, we are expected to use this model to develop more precise high-order MODIS products in Asia-Pacific region.

Net primary productivity and spatial distribution of vegetation in an alpine wetland, Qinghai-Tibetan Plateau

To initially describe vegetation structure and spatial variation in plant biomass in a typical alpine wetland of the Qinghai-Tibetan Plateau, net primary productivity and vegetation in relationship to environmental factors were investigated. In 2002, the wetland remained flooded to an average water depth of 25 cm during the growing season, from July to mid-September. We mapped the floodline and vegetation distribution using GPS (global positioning system). Coverage of vegetation in the wetland was 100%, and the vegetation was zonally distributed along a water depth gradient, with three emergent plant zones (Hippuris vulgaris-dominated zone, Scirpus distigmaticus-dominated zone, and Carex allivescers-dominated zone) and one submerged plant zone (Potamogeton pectinatus-dominated zone). Both aboveground and belowground biomass varied temporally within and among the vegetation zones. Further, net primary productivity (NPP) as estimated by peak biomass also differed among the vegetation zones; aboveground NPP was highest in the Carex-dominated zone with shallowest water and lowest in the Potamogeton zone with deepest water. The area occupied by each zone was 73.5% for P. pectinatus, 2.6% for H. vulgaris, 20.5% for S. distigmaticus, and 3.4% for C. allivescers. Morphological features in relationship to gas-transport efficiency of the aerial part differed among the emergent plants. Of the three emergent plants, H. vulgaris, which dominated in the deeper water, showed greater morphological adaptability to deep water than the other two emergent plants.

Carbon dioxide dynamics and controls in a deep-water wetland on the Qinghai-Tibetan Plateau

To initially characterize the dynamics and environmental controls of CO2, ecosystem CO2 fluxes were measured for different vegetation zones in a deep-water wetland on the Qinghai-Tibetan Plateau during the growing season of 2002. Four zones of vegetation along a gradient from shallow to deep water were dominated, respectively by the emergent species Carex allivescens V. Krez., Scirpus distigmaticus L., Hippuris vulgaris L., and the submerged species Potamogeton pectinatus L. Gross primary production (GPP), ecosystem respiration (Re), and net ecosystem production (NEP) were markedly different among the vegetation zones, with lower Re and GPP in deeper water. NEP was highest in the Scirpus-dominated zone with moderate water depth, but lowest in the Potamogeton-zone that occupied approximately 75% of the total wetland area. Diurnal variation in CO2 flux was highly correlated with variation in light intensity and soil temperature. The relationship between CO2 flux and these environmental variables varied among the vegetation zones. Seasonal CO2 fluxes, including GPP, Re, and NEP, were strongly correlated with aboveground biomass, which was in turn determined by water depth. In the early growing season, temperature sensitivity (Q(10)) for Re varied from 6.0 to 8.9 depending on vegetation zone. Q(10) decreased in the late growing season. Estimated NEP for the whole deep-water wetland over the growing season was 24 g C m(-2). Our results suggest that water depth is the major environmental control of seasonal variation in CO2 flux, whereas photosynthetic photon flux density (PPFD) controls diurnal dynamics.

The potential importance of grazing to the fluxes of carbon dioxide and methane in an alpine wetland on the Qinghai-Tibetan Plateau

To assess the impact of livestock grazing on the emission of greenhouse gases from grazed wetlands, we examined biomass growth of plants, CO2 and CH4 fluxes under grazing and non-grazing conditions on the Qinghai-Tibetan Plateau wetland. After the grazing treatment for a period of about 3 months, net ecosystem CO2 uptake and aboveground biomass were significantly smaller, but ecosystem CH4 emissions were remarkably greater, under grazing conditions than under non-grazing conditions. Examination of the gas-transport system showed that the increased CH4 emissions resulted from mainly the increase of conductance in the gas-transport system of the grazed plants. The sum of global warming potential, which was estimated from the measured CO2 and CH4 fluxes, was 5.6- to 11.3-fold higher under grazing conditions than under non-grazing conditions. The results suggest that livestock grazing may increase the global warming potential of the alpine wetlands. (c) 2005 Elsevier Ltd. All rights reserved.

Methane emissions from different vegetation zones in a Qinghai-Tibetan Plateau wetland

We measured methane (CH4) emissions in the Luanhaizi wetland, a typical alpine wetland on the Qinghai-Tibetan Plateau, China, during the plant growth season (early July to mid-September) in 2002. Our aim was to quantify the spatial and temporal variation of CH4 flux and to elucidate key factors in this variation. Static chamber measurements of CH4 flux were made in four vegetation zones along a gradient of water depth. There were three emergent-plant zones (Hippuris-dominated; Scirpus-dominated; and Carex-dominated) and one submerged-plant zone (Potamogeton-dominated). The smallest CH4 flux (seasonal mean = 33.1 mg CH4 m(-2) d(-1)) was, observed in the Potamogeton-dominated zone, which occupied about 74% of the total area of the wetland. The greatest CH4 flux (seasonal mean = 214 mg CH4 m(-2) d(-1)) was observed in the Hippuris-dominated zone, in the second-deepest water area. CH4 flux from three zones (excluding the Carex-dominated zone) showed a marked diurnal change and decreased dramatically under dark conditions. Light intensity had a major influence on the temporal variation in CH4 flux, at least in three of the zones. Methane fluxes from all zones increased during the growing season with increasing aboveground biomass. CH4 flux from the Scirpus-dominated zone was significantly lower than in the other emergent-plant zones despite the large biomass, because the root and rhizome intake ports for CH4 transport in the dominant species were distributed in shallower and more oxidative soil than occupied in the other zones. Spatial and temporal variation in CH4 flux from the alpine wetland was determined by the vegetation zone. Among the dominant species in each zone, there were variations in the density and biomass of shoots, gas-transport system, and root-rhizome architecture. The CH4 flux from a typical alpine wetland on the Qinghai-Tibetan Plateau was as high as those of other boreal and alpine wetlands. (C) 2004 Elsevier Ltd. All rights reserved.

Monitoring Activities from Multiple Video Streams: Establishing a Common Coordinate Frame

Passive monitoring of large sites typically requires coordination between multiple cameras, which in turn requires methods for automatically relating events between distributed cameras. This paper tackles the problem of self-calibration of multiple cameras which are very far apart, using feature correspondences to determine the camera geometry. The key problem is finding such correspondences. Since the camera geometry and photometric characteristics vary considerably between images, one cannot use brightness and/or proximity constraints. Instead we apply planar geometric constraints to moving objects in the scene in order to align the scene"s ground plane across multiple views. We do not assume synchronized cameras, and we show that enforcing geometric constraints enables us to align the tracking data in time. Once we have recovered the homography which aligns the planar structure in the scene, we can compute from the homography matrix the 3D position of the plane and the relative camera positions. This in turn enables us to recover a homography matrix which maps the images to an overhead view. We demonstrate this technique in two settings: a controlled lab setting where we test the effects of errors in internal camera calibration, and an uncontrolled, outdoor setting in which the full procedure is applied to external camera calibration and ground plane recovery. In spite of noise in the internal camera parameters and image data, the system successfully recovers both planar structure and relative camera positions in both settings.

Declarative sensor knowledge in a robot monitoring system

Hardy, N. W., Barnes, D. P., Lee, M. (1987). Declarative sensor knowledge in a robot monitoring system. In: Languages for Sensor-Based Control in Robotics, Ulrich Rembold and Klaus H?rmann (eds), Springer-Verlag, p. 169-188.

A control and monitoring system for multiple-sensor industrial robots

Barnes, D. P., Lee, M. H., Hardy, N. W. (1983). A control and monitoring system for multiple-sensor industrial robots. In Proc. 3rd. Int. Conf. Robot Vision and Sensory Controls, Cambridge, MA. USA., 471-479.

Understanding student information behavior in relation to electronic information services: lessons from longitudinal monitoring and evaluation Part 1

Rowley, J.& Urquhart, C. (2007). Understanding student information behavior in relation to electronic information services: lessons from longitudinal monitoring and evaluation Part 1. Journal of the American Society for Information Science and Technology, 58(8), 1162-1174. Sponsorship: JISC