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101.
To describe the contribution of garden dormice to the epizootiology of Lyme disease, we compared their reservoir capacity for these pathogens to that of other sympatric hosts. Garden dormice are trapped most abundantly during early spring and again during midsummer, when their offspring forage. They are closely associated with moist forests. Garden dormice serve as hosts to nymphal ticks far more frequently than do other small mammals. Spirochetal infection is most prevalent in dormice, and many more larval ticks acquire infection in the course of feeding on these than on other rodents in the study site. Mature dormice appear to contribute more infections to the vector population than juveniles do. Replete larval ticks generally detach while their dormouse hosts remain within their nests. The population of garden dormice contributes five- to sevenfold more infections to the vector population than the mouse population does. Their competence, nymphal feeding density, and preference for a tick-permissive habitat combine to favor garden dormice over other putative reservoir hosts of Lyme disease spirochetes. 相似文献
102.
Jongho Lee Carmel Majidi Bryan Schubert Ronald S Fearing 《Journal of the Royal Society Interface》2008,5(25):835-844
Gecko-inspired microfibre arrays with 42 million polypropylene fibres cm(-2) (each fibre with elastic modulus 1 GPa, length 20 microm and diameter 0.6 microm) were fabricated and tested under pure shear loading conditions, after removing a preload of less than 0.1 N cm(-2). After sliding to engage fibres, 2 cm2 patches developed up to 4N of shear force with an estimated contact region of 0.44 cm2. The control unfibrillated surface had no measurable shear force. For comparison, a natural setal patch tested under the same conditions on smooth glass showed approximately seven times greater shear per unit estimated contact region. Similar to gecko fibre arrays, the synthetic patch maintains contact and increases shear force with sliding. The high shear force observed (approx. 210 nN per fibre) suggests that fibres are in side contact, providing a larger true contact area than would be obtained by tip contact. Shear force increased over the course of repeated tests for synthetic patches, suggesting deformation of fibres into more favourable conformations. 相似文献
103.
In wireless networks, users are typically coupled by interference. Hence, resource allocation can strongly depend on receive strategies, such as beamforming, CDMA receivers, etc. We study the problem of minimizing the total transmission power while maintaining individual quality-of-service (QoS) values for all users. This problem can be solved by the fixed-point iteration proposed by Yates (1995) as well as by a recently proposed matrix-based iteration (Schubert and Boche, 2007). It was observed by numerical simulations that the matrix-based iteration has interesting numerical properties, and achieves the global optimum in only a few steps. However, an analytical investigation of the convergence behavior has been an open problem so far. In this paper, we show that the matrix-based iteration can be reformulated as a Newton-type iteration of a convex function, which is not guaranteed to be continuously differentiable. Such a behavior can be caused by ambiguous representations of the interference functions, depending on the choice of the receive strategy. Nevertheless, superlinear convergence can be shown by exploiting the special structure of the problem. Namely, the function is convex, locally Lipschitz continuous, and an invertible directional derivative exists for all points of interest. 相似文献
104.
The authors investigated the impact of response activation on dual-task performance by presenting a subliminal prime before the stimulus in Task 2 (S2) of a psychological refractory period (PRP) task. Congruence between prime and S2 modulated the reaction times in Task 2 at short stimulus onset asynchrony despite a PRP effect. This Task 2 congruence effect was paralleled by a Task 1 congruence effect and emerged exclusively under conditions of cross talk, whereas it did not occur under dual-task conditions preventing cross talk between tasks. This suggests that response activation operates during the PRP in dual tasks and affects the response times in Task 2 via cross talk between common processing elements at prebottleneck stages but not by directly affecting the postbottleneck stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
105.
During electrochemical oxidation of ReS2 crystals the anodic photocurrent in aqueous electrolytes increases up to 140-fold. This phenomenon is accompanied by the formation of an unstable Re2O7 surface layer and a characteristic change of the photocurrent spectrum in the near UV. This is explained in terms of the formation of a heterojunction between ReS2 and Re2O7. Upon addition of the I–/I
3
–
redox couple a temporarily working electrochemical solar cell is obtained. Since the observed quantum efficiency exceeded the theoretical expectation, further studies of the interfacial quantum processes were made. It turned out that the enhancement effect is due to light collection by scattering processes in the highly refractive Re2O7 film and at the epoxy insulation. 相似文献
106.
107.
J. T. Reilly C. N. Schubert J. R. Lindner M. D. Donohue R. M. Kelly 《Chemical Engineering Communications》1990,93(1):181-191
Absorption rates of carbonyl sulfide and carbon dioxide into aqueous methyldiethanolamine solutions with and without heterocyclic amine additives were measured in a stirred cell apparatus. All of the heterocyclic amine additives catalyzed COS absorption more strongly than that for CO2. In instances in which absorption rates were improved by the additives, those with the lowest pKb's were the most effective, although steric factors also apparently influence reaction kinetics. 相似文献
108.
J García-Arumí R Pascual MJ Fonseca FR Isart R Casaroli C Mateo B Corcostegui 《Canadian Metallurgical Quarterly》1997,211(6):344-350
Relationships from benefits-costs analyses in radiography are presented. The impact of several factors (equipment, frequency of examinations, ...) on the planning of a department and special financial aspects, e.g., leasing of equipment, are discussed. The cost relationships of conventional versus digital radiography are demonstrated for the example of a 1000-bed hospital. 相似文献
109.
110.
András Schubert 《Scientometrics》2010,84(1):133-147
Hirsch’s concept of h-index was used to define a similarity measure for journals. The h-similarity is easy to calculate from
the publicly available data of the Journal Citation Reports, and allows for plausible interpretation. On the basis of h-similarity,
a relative eminence indicator of journals was determined: the ratio of the JCR impact factor to the weighted average of that
of similar journals. This standardization allows journals from disciplines with lower average citation level (mathematics,
engineering, etc.) to get into the top lists. 相似文献