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991.
Charles P.M. Williams P.J. Wood A.K. Ogden R. Carter A.C. 《Electronics letters》1992,28(12):1084-1085
The design and fabrication of OEICs on semi-insulating InP substrates comprising 1300 nm DFB lasers, 1300/1530 nm wavelength duplexers and monitor photodiodes is described. OEIC lasing thresholds were as low as 20 mA. The through-state crosstalk for the integrated duplexer was typically -12 dB. Linear tracking of the laser output by the monitor photodiode was achieved with sensitivities in the region of 70 mu A/mW. The OEICs operated successfully in a 622 Mbit/s bidirectional optical link.<> 相似文献
992.
993.
The present study examined age differences in trust and reliance of an automated decision aid. In Experiment 1, older and younger participants performed a simple mathematical task concurrent with a simulated medication management task. The decision aid was designed to facilitate medication management, but with varying reliability. Trust, self-confidence and usage of the aid were measured. The results indicated that older adults had greater trust in the aid and were less confident in their performance, but they did not calibrate trust differently than younger adults. In Experiment 2, a variant of the same task was used to investigate whether older adults are subject to over-reliance on the automation. Differences in omission and commission errors were examined. The results indicated that older adults were more reliant on the decision aid and committed more automation-related errors. A signal detection analyses indicated that older adults were less sensitive to automation failures. Results are discussed with respect to the perceptual and cognitive factors that influence age differences in the use of fallible automation. 相似文献
994.
Michael Bernas Marlys Witte Benjamin Kriederman Peré Summers Charles Witte 《IEEE engineering in medicine and biology magazine》2005,24(2):58-68
The ongoing NCCAM-supported experimental and clinical translational approaches should shed light not only on the physiologic mechanisms underlying the benefits of massage therapy but could also, if successful in defined populations of patients, have a substantial impact by providing a simpler, more cost-effective LE treatment alternative worldwide. 相似文献
995.
In this study preschool-age children made predictions for a set of salient probabilistic causes. Of interest was whether the children viewed outcomes of familiar causes of illness as definite or as probabilistic. In Experiment 1, children judged that a common cause would affect all members of a group in the same way. In Experiment 2, children believed they could definitely predict illness outcomes in a single case. These judgments contrasted with adults' variable and uncertain predictions. Children did recognize uncertainty in outcomes dependent on voluntary choices. Experiment 3 presented both high- and low-potency causes of illness. Children treated all causes of illness as nonprobabilistic. These results are discussed in the context of children's understanding of causal relations and the sources of variability. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
Networks based on the High Performance Parallel Interface (HIPPI) will become the norm at Los Alamos National Laboratory. The ramification of such a high-speed networking paradigm on scientific visualization are enormous. Not only will scientists have the capability of networked framebuffer animation loops in their offices, but also the partitioning of graphics tasks between MIMD, SIMD, and specialized hardware will be feasible. Of course, as bandwidth increases, the problem size quickly grows to exceed whatever the limits are. For this reason, the investigation of gigabyte networks is currently underway at Los Alamos National Laboratory. 相似文献
997.
CJ Charles MT Rademaker AM Richards GJ Cooper DH Coy MG Nicholls 《Canadian Metallurgical Quarterly》1998,139(4):1746-1751
Adrenomedullin, the recently described vasodilator that exhibits potent hypotensive actions when administered systemically, is also found in the central nervous system, suggesting a role for adrenomedullin as a neurohormone. However, only a limited number of studies have examined the central effects of adrenomedullin. Therefore, we have examined the integrative hemodynamic, renal, and hormonal effects of intracerebroventricular (I.C.V.) adrenomedullin in conscious sheep. Eight surgically prepared sheep received I.C.V. infusions of adrenomedullin at two doses (2 ng/kg x min followed immediately by 20 ng/kg x min each for 90 min) in a vehicle-controlled study. Water deprivation for 48 h before control infusion resulted in sheep drinking 2617 +/- 583 ml in the 90-min period following reintroduction of water. On the adrenomedullin day, drinking was halved to 1392 +/- 361 ml (P < 0.05). Adrenomedullin had no significant effect on urinary volume and sodium excretion. Plasma adrenomedullin levels remained unchanged during control infusions but were elevated by the end of I.C.V. adrenomedullin infusions (P < 0.001). Plasma ANP levels were also increased approximately 50% (P < 0.05). Plasma levels of both ACTH and cortisol were also increased 3- to 4-fold in response to I.C.V. adrenomedullin (P < 0.05). There was no significant difference in arterial pressure, heart rate, or cardiac output between study days. In conclusion, adrenomedullin within the central nervous system may have at least two roles: modulation of the hypothalamo-pituitary-adrenal axis and protection against fluid overload. 相似文献
998.
Mechanisms and function of intercellular calcium signaling 总被引:3,自引:0,他引:3
Intercellular Ca2+ waves initiated by mechanical or chemical stimuli propagate between cells via gap junctions. The ability of a wide diversity of cells to display intercellular Ca2+ waves suggests that these Ca2+ waves may represent a general mechanism by which cells communicate. Although Ca2+ may permeate gap junctions, the intercellular movement of Ca2+ is not essential for the propagation of Ca2+ waves. The messenger that moves from one cell to the next through gap junctions appears to be IP3 and a regenerative mechanism for IP3 may be required to effect multicellular communication. Extracellularly mediated Ca2+ signaling also exists and this could be employed to supplement or replace gap junctional communication. The function of intercellular Ca2+ waves may be the coordination of cooperative cellular responses to local stimuli. 相似文献
999.
CharlesE.Semler 《中国耐火材料》2003,12(1):1-5
Factors affecting the U.S.refractories industry,such as decreasing demand,mergers ,and decreased education are discussed,along with manufacturing statistics(i.e.,annual value and product trends),indicating that the U.S.market has declined for five straight years,.Research activities have changed,with more emphasis on practical,applied projects,which have continued to produce important advances,Many challenges and opportunities remain,based on the current and future business requirements. 相似文献
1000.
Random intercept models for binary data are useful tools for addressing between-subject heterogeneity. Unlike linear models, the non-linearity of link functions used for binary data force a distinction between marginal and conditional interpretations. This distinction is blurred in probit models with a normally distributed random intercept because the resulting model implies a probit marginal link as well. That is, this model is closed in the sense that the distribution associated with the marginal and conditional link functions and the random effect distribution are all of the same family. It is shown that the closure property is also attained when the distributions associated with the conditional and marginal link functions and the random effect distribution are mixtures of normals. The resulting flexible family of models is demonstrated to be related to several others present in the literature and can be used to synthesize several seemingly disparate modeling approaches. In addition, this family of models offers considerable computational benefits. A diverse series of examples is explored that illustrates the wide applicability of this approach. 相似文献