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121.
Active services are application-specified programs that are executed inside the network. The location where the active service is executed plays an important role. The dynamic behavior of networks requires that the selection of the most suitable location to instantiate a service is done at run time. To dynamically place an active service, information about the network (topology, bandwidth) and the application (type of the service) is necessary. This paper describes a method to dynamically search for available active service locations in the Internet. To be deployed in the current Internet, a solution is required to scale well to large networks, and to demand as little changes to the Internet as possible, especially not at lower network layers. Finally, the solution must be flexible and customizable to take application requirements into account. The proposed solution makes use of the routing path between two end systems. Active service locations that are located close to the routing path are then found via DNS queries. The evaluation shows that the application pays an overhead at start up time. For applications that can tolerate a start up delay, we show with three experiments using a video and an image application that the quality of the application can be increased by a dynamic placement of active services.  相似文献   
122.
Cues that are contingently paired with unconditioned, rewarding stimuli can acquire rewarding properties themselves through a process known as the attribution of incentive salience, or the transformation of neutral stimuli into attractive, "wanted'' stimuli capable of motivating behavior. Pavlovian conditioned approach (PCA) develops after the response-independent presentation of a conditioned stimulus (CS; e.g., a lever) that predicts the delivery of an unconditioned stimulus (US; e.g., a food pellet) and can be used to measure incentive salience. During training, three patterns of conditioned responses (CRs) can develop: sign-tracking behavior (CS-directed CR), goal-tracking behavior (US-directed CR), and an intermediate response (both CRs). Sign-trackers attribute incentive salience to reward-related cues and are more vulnerable to cue-induced reinstatement of drug-seeking as well as other addiction-related behaviors, making PCA a potentially valuable procedure for studying addiction vulnerability. Here, we describe materials and methods used to elicit PCA behavior from rats as well as analyze and interpret PCA behavior in individual experiments.  相似文献   
123.
124.
Internet gaming disorder (IGD) is not currently a recognized diagnosis in the Diagnostic and Statistical Manual for Mental Disorders-5 (DSM-5). However, IGD has been noted to warrant further research for possible future inclusion in the DSM. In many ways, IGD strongly resembles substance and gambling addictions. Such characteristics include tolerance, withdrawal, and social and occupational neglect resulting from increased time invested in video game use and acquisition. The use of similar or closely related media is also seen, which mirrors the natural course of substance and gambling addictions. We present a case of a 22-year-old man who exhibited IGD and problems associated with pornography use. This case report exemplifies the sequelae of IGD. Our paper also reviews the possible mechanisms of behavioral addiction, as well as the status of IGD as a potential subcategory of behavioral addiction. Additional research is needed to determine if IGD co-occurs with problematic use of pornography.  相似文献   
125.
Marijuana has been shown to lower intraocular pressure (IOP) but with limited duration of action and numerous adverse effects. Use of marijuana to lower IOP as a means of glaucoma treatment would require frequent use throughout the day, leading to significant adverse effects, possible progression toward Cannabis Use Disorder (CUD), and/or withdrawal symptoms. The treatment of glaucoma based on the cannabis plant or drugs based on the cannabinoid molecule should be considered carefully before being prescribed. Considerations should include the adverse physical and psychological adverse effects, including substance abuse. Currently, the deleterious effects of marijuana outweigh the benefits of its IOP-lowering capacity in most glaucoma patients. Under extremely rare circumstances, a few categories of glaucoma patients may be potential candidates for treatment with medical marijuana. Further studies on alternate routes and more focused means of cannabinoid molecule delivery to the eye for glaucoma treatment are needed.  相似文献   
126.
在社会需要和科技进步的双重推动下,"3R"原则和动物试验替代方法正在从道德理念向实验技术转变。站在全球科技发展的高度,结合我国实验动物替代领域的现状和未来趋势,利用MSSQLServer2000构建中国替代方法研究评价中心共识平台,管理信息数据库,用WEB技术将数据库与internet WWW(WorldWideWeb)页面连接,构成动态的咨询平台和信息数据网络查询系统。该共识平台的建立为国内从事实验动物及替代方法研究应用的用户提供了便利,起到了国内外替代技术交流的桥梁作用。  相似文献   
127.
When newly hatched larvae of P. rapae were transferred to cowpea foliage, they readily accepted this non-host as food, whereas later instars that had fed on cabbage rejected cowpea. However, when cowpea leaf discs were treated with aqueous extracts of cabbage foliage, they were accepted by cabbage-reared larvae. Experiments were conducted to determine whether larvae reared on one host plant would be stimulated to feed by extracts of other hosts. Larvae reared on Brassica juncea, Cleome spinosa, Tropaeolum majus, Sinapis alba, Alliaria petiolata, Barbarea vulgaris and cabbage (Brassica oleracea) were offered extracts of each of the other host plants on cowpea discs in choice assays. Larvae were generally stimulated to feed by extracts of all the alternate hosts, but quantitative differences in consumption occurred. In most cases, levels of discrimination between treatment and control cowpea discs showed no significant preference for extracts of the previously experienced plant. Since the test plants (and their extracts) contain glucosinolates of widely different structures, a general addiction to glucosinolates was suggested. A single glucosinolate, sinigrin, was sufficient to elicit feeding by cabbage-reared larvae. The time required for individual neonates to become addicted to glucosinolates as they fed on cabbage, as measured by refusal of cowpea, varied from 6 to 30 hours. Bioassays of cowpea extracts failed to show any deterrent activity and, therefore, supported the conclusion that addiction to glucosinolates is responsible for the fixation of P. rapae larvae on their host plants.  相似文献   
128.
Video games have surged in popularity due to their entertainment factor and, with recent innovation, their use in health care. This review explores the dual facets of video games in treating vision impairment in amblyopia as well as their potential for overuse and addiction. Specifically, this review examines video game addiction from a biopsychosocial perspective and relates the addictive qualities of video games with their use as a therapeutic treatment for amblyopia. Current literature supports both the identification of video game addiction as a disease, as well as the therapeutic potential of video games in clinical trials. We show the need for clinicians to be aware of the dangers associated with video game overuse and the need for future studies to examine the risks associated with their health care benefits.  相似文献   
129.
Epigenetic regulation of cellular identity and function is at least partly achieved through changes in covalent modifications on DNA and histones. Much progress has been made in recent years to understand how these covalent modifications affect cell identity and function. Despite the advances, whether and how epigenetic factors contribute to memory formation is still poorly understood. In this review, we discuss recent progress in elucidating epigenetic mechanisms of learning and memory, primarily at the DNA level, and look ahead to discuss their potential implications in reward memory and development of drug addiction.  相似文献   
130.
内感受是机体对自身生理状态的感觉.近年来,越来越多的研究证据表明,内感受可以调控成瘾行为,岛叶是其发挥作用的重要神经基础之一.目前,对岛叶作用机制的研究正受到高度重视.本文从岛叶的基本结构和功能出发,结合近几年来岛叶调控成瘾行为、行为抑制以及情感决策的重要发现,讨论岛叶在成瘾发生及发展过程中的可能作用及其机制,并根据已有的实验证据,试图提出较为合理的研究展望,以推动相关神经环路和神经化学机制研究的深入.  相似文献   
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