排序方式: 共有53条查询结果,搜索用时 15 毫秒
1.
Agenesis of the corpus callosum in a mother and son 总被引:1,自引:0,他引:1
Most reported familial cases of agenesis of the corpus callosum have followed either an autosomal recessive or an X-linked recessive pattern of inheritance. To the best of our knowledge, there is only one previous report of a family showing clear-cut autosomal dominant inheritance. We present the second such family, among whom a mother and her son had moderately severe coordination problems and low-normal intelligence. We suggest that agenesis of the corpus callosum, when transmitted as an autosomal dominant trait, is clinically characterized by a relatively milder phenotype than that occurring when inheritance is either autosomal or X-linked recessive and may be more common than has been thought. 相似文献
2.
Berger Andrea; Sadeh Michelle; Tzur Gabriel; Shuper Avinoam; Kornreich Liora; Inbar Dov; Cohen Ian J.; Michowiz Shalom; Yaniv Isaac; Constantini Shlomi; Kessler Yoav; Merian Nachshon 《Canadian Metallurgical Quarterly》2005,19(3):362
The authors of this study investigated task switching following cerebellar damage. The study group consisted of 7 children and adolescents (M age = 13.8 years) who underwent surgical removal of a benign posterior fossa tumor. They were tested at a sufficient interval after surgery (M lag = 6.13 years) for restoration of normal cognitive skills and intelligence. Although all showed normal learning of the task compared with control participants, when rapid behavioral changes were required (short preparation time), they exhibited behavioral rigidity manifested by enhanced switching cost. These results are in line with another study on serial reaction time with the same patients (A. Berger et al., in press). They have important implications for our understanding of the cognitive sequelae of early cerebellar damage as well as the involvement of the cerebellum in task switching. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
Increasingly, application developers are looking for ways to provide users with higher levels of personalization that capture different elements of a user’s operating context, such as her location, the task that she is currently engaged in, who her colleagues are, etc. While there are many sources of contextual information, they tend to vary from one user to another and also over time. Different users may rely on different location tracking functionality provided by different cell phone operators; they may use different calendar systems, etc. In this article, we describe work on a Semantic e-Wallet aimed at supporting automated identification and access of personal resources, each represented as a Semantic Web Service. A key objective is to provide a Semantic Web environment for open access to a user’s contextual resources, thereby reducing the costs associated with the development and maintenance of context-aware applications. A second objective is, through Semantic Web technologies, to empower users to selectively control who has access to their contextual information and under which conditions. This work has been carried out in the context of myCampus, a context-aware environment aimed at enhancing everyday campus life. Empirical results obtained on Carnegie Mellon’s campus are discussed. 相似文献
4.
Predictability of prices and availability are becoming less predictable in emerging supply chain environments, as product lifecycles shorten and organizations pursue increased agility. This leads to new competitive and strategic interactions among actors across the supply chain. It also threatens to overwhelm human decision capabilities with a combinatorial explosion of possibilities. Recent advances in technical infrastructure have enabled new types of interorganizational interactions, but have not addressed the need for fundamentally new kinds of decision support systems that can help tame the complexity of this emerging environment. The papers in this special issue describe progress in semi-autonomous trading agents that are being developed to meet this need. 相似文献
5.
Surface Cleanliness Effect on Lunar Soil Shear Strength 总被引:1,自引:0,他引:1
Lunar soil consists of dry silty sand. Observations and measurements conducted during Surveyor, Apollo, and Luna missions indicated that the lunar soil is unusually cohesive. This is attributable to the fact that thick layers of adsorbed gases, which coat and lubricate soil particles on Earth, are absent in the ultrahigh vacuum on the Moon. “Surface cleanliness” is introduced as a new parameter for describing soils in different planetary environments. It is defined as the dimensionless inverse of adsorbate thickness on solid surfaces. By this definition, the ultrahigh vacuum on the Moon is associated with high surface cleanliness, while Earth's atmosphere is associated with low surface cleanliness. A model is developed to calculate surface cleanliness and its effect on shear strength in any planetary environment. Results obtained from the model compare well with data from previous ultrahigh vacuum and variable temperature laboratory experiments on Earth soils. It is shown that surface cleanliness is an important parameter with respect to lunar soil shear strength. 相似文献
6.
JS Sadeh D Rudikoff ML Gordon J Bowden BD Goldman M Lebwohl 《Canadian Metallurgical Quarterly》1997,133(6):747-750
To investigate the mechanisms of the hypolipidemic effect of monatepil, a new class of calcium antagonists with alpha 1-adrenergic blocking activity, we examined the effects of the drug on low-density lipoprotein (LDL) receptor activity and the level of LDL receptor mRNA present in cultured human skin fibroblasts. At concentrations of 2 x 10(-5) M, monatepil increased the binding (248 +/- 43%; mean +/- SD), internalization (374 +/- 18%), and degradation (145 +/- 2%) of 125I-LDL in human skin fibroblasts (n = 3, p < 0.05). Treatment of human skin fibroblasts with 2 x 10(-5) M of monatepil for 6 hours resulted in an increase in LDL receptor mRNA to 163% of the control level (n = 2), as shown by Northern blot analysis. Our results suggest that the hypolipidemic clinical effects of monatepil may be due to increased LDL receptor activity. 相似文献
7.
A novel synthesis method of very high aspect ratio metal nanowires is described. The synthesis utilizes a nanoporous membrane as a template and self-electrophoresis as a directed force that continuously push formed nanowires out of the pores in a rate that is identical to the rate of their elongation. As a result, while the pores of membranes are only 6 microm long, the formed nanowires could be more than 100 microm long. 相似文献
8.
G. Bagheri Marandi K. Esfandiari F. Biranvand M. Babapour S. Sadeh G. R. Mahdavinia 《应用聚合物科学杂志》2008,109(2):1083-1092
Poly(acrylamide) superabsorbent hydrogel was synthesized through crosslinking method. Formaldehyde was used as a crosslinking agent. To achieve a hydrogel with high swelling capacity, the resulted hydrogels were saponified using NaOH solution at high temperature. During saponification, ammonia gas is produced from hydrolysis reaction of amide groups. The arising of ammonia produces porous structure in hydrogels, which is confirmed using scanning electron microscopy. The conversion of amide groups to carboxylate groups was identified by FTIR spectroscopy. The reaction variables in both crosslinking and hydrolysis reactions that affect the swelling of hydrogels were optimized. The swelling of the hydrogels in various salt solutions with various valencies and radii was studied. Also, the absorbency under load was measured. The hydrogels exhibited pH-sensitivity characteristics. A sharp swelling change was observed in lieu of pH variations in a wide range (1–13). The swelling variations were explained according to the swelling theory based on the hydrogel chemical structure. The pH-reversibility and on–off switching behavior makes the intelligent hydrogels as good candidates for considering as potential drug carries. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
9.
Suicidality represents one of the most important areas of risk for adolescents, with both internalizing (e.g., depression, anxiety) and externalizing–antisocial (e.g., substance use, conduct) disorders conferring risk for suicidal ideation and attempts (e.g., Bridge, Goldstein, & Brent, 2006). However, no study has attended to gender differences in relationships between suicidality and different facets of psychopathic tendencies in youth. Further, very little research has focused on disentangling the multiple manifestations of suicide risk in the same study, including behaviors (suicide attempts with intent to die, self-injurious behavior) and general suicide risk marked by suicidal ideation and plans. To better understand these relationships, we recruited 184 adolescents from the community and in treatment. As predicted, psychopathic traits and depressive symptoms in youth showed differential associations with components of suicidality. Specifically, impulsive traits uniquely contributed to suicide attempts and self-injurious behaviors, above the influence of depression. Indeed, once psychopathic tendencies were entered in the model, depressive symptoms only explained general suicide risk marked by ideation or plans but not behaviors. Further, callous–unemotional traits conferred protection from suicide attempts selectively in girls. These findings have important implications for developing integrative models that incorporate differential relationships between (a) depressed mood and (b) personality risk factors (i.e., impulsivity and callous–unemotional traits) for suicidality in youth. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
10.
A new and accurate fault location algorithm for combined transmission lines using Adaptive Network-Based Fuzzy Inference System 总被引:1,自引:0,他引:1
This paper presents a new and accurate algorithm for locating faults in a combined overhead transmission line with underground power cable using Adaptive Network-Based Fuzzy Inference System (ANFIS). The proposed method uses 10 ANFIS networks and consists of 3 stages, including fault type classification, faulty section detection and exact fault location. In the first part, an ANFIS is used to determine the fault type, applying four inputs, i.e., fundamental component of three phase currents and zero sequence current. Another ANFIS network is used to detect the faulty section, whether the fault is on the overhead line or on the underground cable. Other eight ANFIS networks are utilized to pinpoint the faults (two for each fault type). Four inputs, i.e., the dc component of the current, fundamental frequency of the voltage and current and the angle between them, are used to train the neuro-fuzzy inference systems in order to accurately locate the faults on each part of the combined line. The proposed method is evaluated under different fault conditions such as different fault locations, different fault inception angles and different fault resistances. Simulation results confirm that the proposed method can be used as an efficient means for accurate fault location on the combined transmission lines. 相似文献