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71.
Renaud P. Bouchard S. Proulx R. 《IEEE transactions on information technology in biomedicine》2002,6(3):235-243
Tracking behavior with a virtual spider and a neutral target is compared in fearful and nonfearful subjects. Head-tracking in virtual environments appears to be a scale-free behavior with long-range fractal-like patterns. Moreover, these fractal patterns change according to what the target affords the tracker and the level of behavioral avoidance manifested by the subjects. Results are interpreted in terms of ecological psychology and nonlinear dynamics, and implications for virtual reality (VR) psychology are outlined. 相似文献
72.
Determination of catecholamines by capillary zone electrophoresis with laser-induced fluorescence detection was performed on low-concentration samples, which were derivatized with naphthalene-2,3-dicarboxaldehyde to give highly fluorescent compounds. When the borate concentration in the derivatization medium was decreased from 130 to 13 mM, sensitivity for noradrenaline (NA) and dopamine (DA) was greatly enhanced while resolution between these two compounds decreased. A 50 mM borate concentration in derivatization medium was chosen since it provided maximal resolution between NA and DA, together with a high separation efficiency (3.1 million theoretical plates per meter for DA). The injection of 2.4 nL of a NA and DA solution derivatized at 10(-9) M produced peaks with signal-to-noise ratio of 8:1 and 3:1, respectively, corresponding to 1.8 amol of each catecholamine. The calibration curves were linear when NA and DA solutions were derivatized at concentrations ranging from 10(-6) to 10(-9) M. This method was used to determine NA in brain extracellular fluid: a peak corresponding to a basal level of 5 x 10(-9) M endogeneous NA was observed in microdialysates from the medial frontal cortex of the rat, and its nature was confirmed by both electrophoretic and pharmacological validations. 相似文献
73.
Pediatric anxiety disorders are common illnesses that, if left untreated, may induce academic, family, and interpersonal problems. Cognitive-behavioral techniques and other psychotherapeutic interventions may be adequate for the treatment of most anxiety disorders. For patients with severe symptoms or for whom psychotherapeutic approaches are not adequate, medications are indicated. Among the available medications, the SSRIs are currently the first choice; however, other medications, such as the benzodiazepines and the TCAs, may be used alone or sometimes in combination with the SSRIs. Caution with respect to medication interactions and side effects is indicated. In particular, long-term side effects in these medications have not been well studied. 相似文献
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75.
Separator materials suitable for use in industrial alkaline water electrolysers are surveyed, including both inorganic and organic materials. The properties which make asbestos diaphragms unsuitable for use above 100°C are also reviewed.In summary, potassium titanate and polyantimonic acid separator materials perform well in high-temperature alkali. Oxide-coated metallic diaphragms merit further attention. Polysulfone and polyphenylene sulfide polymers are promising, but will need definite improvement in their wettability. Asbestos stabilization by silicate electrolyte additions may be viable. 相似文献
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78.
Ludovic Apvrille Pierre de Saqui-Sannes Renaud Pacalet Axelle Apvrille 《电信纪事》2006,61(11-12):1347-1368
This paper introduces a new environment for developing distributed systems. It is based on theTurtle uml profile. Analysis and design phases, described in previous papers, have been extended with an additional deployment phase. In this new step,Turtle components are deployed over hardware execution nodes, and nodes are connected together throughout links,Turtle deployment diagrams are given a formal semantics inRt-lotos, therefore following the approach used forTurtle analysis and design diagrams. Moreover, the paper presents a Java code generator which outputs appropriate Java code forTurtle deployment diagrams. This code is automatically deployable on networks because it implements node communication using network protocols such asUdp orRmi. ttool, the turtle toolkit has been extended to support these new diagrams and code generators. The attack of protected data exchanged throughout securedHttp sessions serves as example. 相似文献
79.
Linderholm P Marescot L Loke MH Renaud P 《IEEE transactions on bio-medical engineering》2008,55(1):138-146
We present a novel, inexpensive, and fast microimpedance tomography system for two-dimensional imaging of cell and tissue cultures. The system is based on four-electrode measurements using 16 planar microelectrodes (5 microm x 4 mm) integrated into a culture chamber. An Agilent 4294A impedance analyzer combined with a front-end amplifier is used for the impedance measurements. Two-dimensional images are obtained using a reconstruction algorithm. This system is capable of accurately resolving the shape and position of a human hair, yielding vertical cross sections of the object. Human epithelial stem cells (YF 29) are also grown directly on the device surface. Tissue growth can be followed over several days. A rapid resistivity decrease caused by permeabilized cell membranes is also monitored, suggesting that this technique can be used in electroporation studies. 相似文献
80.
D.L. Renaud K.C. Dhuyvetter S.J. LeBlanc D.F. Kelton T.F. Duffield M.W. Overton 《Journal of dairy science》2019,102(9):8441-8453
Male calves are purchased from the dairy industry in North America to produce red meat. The price paid for male calves varies widely, and it is unclear which variables influence the price paid for each calf. The objective of this study was to assess how the health traits of calves at the time of arrival and demographic variables affect the breakeven purchase price of a male calf entering the veal industry. A financial model was constructed using the prevalence of health abnormalities, weight at arrival, source of the calf, number of days in the barn, base carcass price, days to mortality, feed costs, season at arrival, interest rate, housing location, carcass dressing percentage, and costs associated with housing, labor, utilities, trucking, and health to calculate the breakeven purchase price and an estimate of profit. Sensitivity analysis was conducted using health variables measured at arrival and demographic variables, including season at arrival and housing location, to identify the factors with the largest impact on the predicted average daily gain, early and late mortality risk, breakeven purchase price, and profit. At the baseline inputs, the average calculated profit was ?$5.36 per calf and it was most sensitive to the location of housing where calves were fed and the body weight of the arriving calf. The mortality risk in the first 21 d after arrival (early) was calculated to be 2.2%, whereas the risk of mortality after 21 d (late) was 3.7%. The risks of early and late mortality were most sensitive to the level of dehydration measured at arrival and the season at arrival for the purchased calves, respectively. The calculated average daily gain was 1.12 kg/d and it was most sensitive to housing location. The breakeven purchase price was calculated to be $242.49 per calf, which was most sensitive to the housing location where the calves were fed. The results of this analysis demonstrate that veal producers need to consider many variables before purchasing calves. In addition to overall market conditions, veal producers should factor health characteristics and the expected performance of the calves they purchase into what they are willing to pay for them. 相似文献