Paralytic shellfish poisoning detection by surface plasmon resonance-based biosensors in shellfish matrixes

The detection of paralytic shellfish poisoning (PSP) toxins in contaminated shellfish is essential for human health preservation. Ethical and technical reasons have prompted the search for new detection procedures as an alternative to the mouse bioassay. On the basis of the detection of molecular interactions by surface plasmon resonance (SPR) biosensors, an inhibition assay was developed using an anti-GTX2/3 antibody (GT13-A) and a saxitoxin-CM5 chip. This assay allowed for quantification of saxitoxin (STX), decarbamoyl saxitoxin (dcSTX), gonyautoxin 2,3 (GTX2/3), decarbamoyl gonyautoxin 2,3 (dcGTX2/3), gonyautoxin 5 (GTX5), and C 1,2 (C1/2) at concentrations from 2 to 50 ng/mL. The interference of five shellfish matrixes with the inhibition assay was analyzed. Mussels, clams, cockles, scallops, and oysters were extracted with five published methods. Ethanol extracts and acetic acid/heat extracts (AOAC Lawrence method) performed adequately in terms of surface regeneration and baseline interference, did not inhibit antibody binding to the chip surface significantly, and presented STX calibration curves similar to buffer controls in all matrixes tested. Hydrochloric acid/heat extracts (AOAC mouse bioassay method) presented surface regeneration problems, and although ethanol-acetic acid/dichloromethane extracts performed well, they were considered too laborious for routine sample testing. Overall the best results were obtained with the ethanol extraction method with calibration curves prepared in blank matrix extracts. STX recovery rate with the ethanol extraction method was 60.52+/-3.72%, with variations among species. The performance of this biosensor assay in natural samples, compared to two AOAC methods for PSP toxin quantification (mouse bioassay and HPLC), suggests that this technology can be useful as a PSP screening assay. In summary, the GT13-A-STX chip inhibition assay is capable of PSP toxin detection in ethanol shellfish extracts, with sufficient sensitivity to quantify the toxin in the range of the European regulatory limit of 80 microg/100 g of shellfish meat.     

A computational approach for peptidomic analysis in taxonomic study of amphibian species

Peptides in the skin secretion of frogs have been studied for some time now because they frequently possess important biological activity such as antibiotic, antimicrobial, or anticancer properties. In this paper, we present a computational approach for measuring the degree of similarity between the entire peptide complement of the skin secretion of specimens from the same or different species. The first step in the analysis is the generation of a mass spectral profile from an experimental high-performance liquid chromatography/electrosparay ionization analysis of the sample. An "overlap" between the mass spectral profiles of different specimens is then proposed as a measure of their similarity. Analysis of specimens from three species of the genus Litoria, viz., L. Aurea, L. Caerulea, and L. Infrafrenata, and Rana Capito of genus Rana shows that the degree of similarity is highest between specimens from the same species, lower for specimens from different species of the same genus, and lowest between specimens from different genera. This indicates that comparison of skin peptide profiles (i.e., mass spectral profiles of skin secretion) is potentially a useful aid in the taxonomic study of amphibian species.     

The design of the SensVest

The SensVest is an item of wearable technology that measures, records and transmits aspects of human physical performance such as heart rate, temperature and movement. The SensVest has been designed for use by science teachers and students to meet their requirements. This paper reports the stages undertaken to design the SensVest, from determining appropriate methods of assessing human performance, to considerations of mounting the technology on the body. Trials have shown that concessions need to be made with ease of use and cost to ensure that the data collected is reliable and usable, with an awareness of the sensors limitations. By designing the SensVest with the wearer in mind a system has been developed that is comfortable, does not inhibit normal performance and is wearable. User trials have shown that meaningful, reliable and useful data can be collected using the SensVest.

Two Dimensional Josephson Junction Arrays

Two dimensional Josephson junction arrays (JJAs) offer theopportunity to study a variety of basic physical concepts. Thepresent review focuses on recent experimental work on thedynamics of JJAs, as characterized by ac conductancemeasurements. The review starts with a discussion of basicphysics necessary to describe JJAs. Some experimentalissues, array fabrication and measurement techniques areconsidered next. In a perpendicular magnetic field, a JJA isan experimental realization of the frustrated XY model, withthe frustration parameter f, corresponding to the number offlux quanta in a unit cell of the array, adjusted by themagnetic field. It is thereby possible to investigate thenature of the ground states at arbitrary frustrations. Phasetransitions are the next topic: the vortex unbindingtransition is observed at integer f-values, while, if thejunction coupling energies are appropriately varied across thearray, at half-integer f-values the Ising transition,associated with chiral symmetry breaking, may be observed.Some aspects of vortex dynamics, a subject which is not yetcompletely understood, are then considered. Under certainconditions there is virtually no pinning in JJAs, they aretherefore ideally suited for the study of vortex dynamics. Thenext topic of this review is concerned with the influence ofdisorder on the ground states and on the phase transitions inJJAs. Site percolation in JJAs has provided some insightsinto the physics of disordered systems and allowed to verifysome theoretical predictions on percolation in two dimensions.A quick look at JJAs in the underdamped regime concludesthis review.     

基于SSL无客户端的共享文件系统的设计

在反向代理的基础上,实现SSL协议,以Samba服务为基础,实现整个局域网内的资源共享的设计,从而实现了外网终端客户能够安全、方便、快捷地接入和访问内网资源.依据该设计方案实现的应用系统在实际的网络环境中测试能够得到比较理想的效果,教育网内用户访问服务器的上传下载速率可以达到100kbit/s以上.     

Dissipation of Turbulent Kinetic Energy near a Bubble Plume

Profiles of the rate of dissipation of turbulent kinetic energy were inferred from temperature microstructure measurements near a bubble plume at the center of a tank with diameter of 13.7 m and maximum depth of 8.3 m. Six sets of between 18 and 51 profiles were collected at airflow rates of 0.1–0.6 L/s, measured at atmospheric pressure, and ensemble-averaged dissipation profiles were calculated. The dissipation in all cases was between 10?8 and 10?6?m2/s3 in most of the profile, but it increased sharply near the water surface. Energy considerations are used to discuss the experimental results in terms of previous numerical models of bubble plume turbulence. Two previous numerical studies show that the turbulence dissipates between 15 and 30% of the available power. In the experiments, the fraction is less than 1% because some of the energy of the plume is used to generate waves on the water surface and the profiles used to compute the volume-averaged dissipation were relatively far from the bubble plume.     

我Q，故我在

作为利用WinRAR内核的WinRAR Q3．40，除了界面更具吸引力之外，其他特点功能和原版基本一致：方便的收藏夹功能、估计压缩功能、直接查找、自制解压安装文件以及档案文件修复功能。     

Predicting change for individual psychotherapy clients on the basis of their nearest neighbors.

This study extended client-focused research by using the nearest neighbor (NN) approach, a client-specific sampling and prediction strategy derived from research on alpine avalanches. Psychotherapy clients (N = 203) seen in routine practice settings in the United Kingdom completed a battery of intake measures and then completed symptom intensity ratings before each session. Forecasts of each client's rate of change and session-by-session variability were computed on the basis of that client's NNs (n = 10-50 in different comparisons). Alternative forecasts used linear or log-linear slopes and were compared with an alternative prediction strategy. Results showed that the NN approach was superior to the alternative model in predicting rate of change, though the advantage was less clear for predicting variability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Flow distribution in spiral mandrel dies

An analysis of flow of a power law fluid in a spiral mandrel die is presented. The analysis is applied to study the effect of various die design parameters on the flow distribution at the end of the spiral mandrel section. Three variables that have a very strong effect on the flow distribution are the number of grooves, the initial clearance, and the groove helix angle. The distribution is improved by increasing the number of grooves, by using a non-zero initial clearance, and a relatively small helix angle. Two more variables that have a significant effect on the flow distribution are the taper angle and the initial groove depth. The optimum taper angle was found to be between 1 and 3 degrees. The distribution uniformity improves with the initial groove depth, while the pressure drop reduces at the same time.