Susceptibility to interference and intrusion errors in consequence of the dominant hemisphere’s hippocampal infarct: A case report

We present a case of a man with an ischemic lesion of the left hippocampus. Detailed neuropsychological assessment revealed susceptibility to retroactive interference and a tendency to make intrusion errors in addition to mild deficits in the verbal memory processes. Although retroactive interference and intrusion errors are normally considered to be the manifestations of frontal lobe dysfunctions, the idea of susceptibility to interference has recently begun to emerge in the literature, as an explanation of medial temporal lobe amnesia. Our data support this new theory, suggesting that one role of the hippocampus is to decrease the interference during the learning processes.     

Rate of intrusion of maxillary incisors in Class II Div 1 malocclusion using skeletal anchorage device and Connecticut intrusion arch

BackgroundNonsurgical correction of deep bite involves either extrusion of posterior teeth, intrusion of incisors, or combination of both. The introduction of skeletal anchorage device with microimplant provides near absolute anchorage without producing any untoward effects on anchor unit. Connecticut Intrusion Arch (CIA) provided an efficient system of intruding anterior segment without producing much adverse affects on anchor teeth.MethodsThe study comprised of 30 patients of Class II Div 1 malocclusion with overbite of >6 mm and required therapeutic extractions of all first premolars, randomly distributed into two groups. Group 1 was treated using orthodontic microimplants, while Group 2 treated with CIA. Lateral cephalograms were taken pre-intrusion (T1) and post-intrusion at the end of six months (T2).ResultsThe rate of intrusion was 0.51 and 0.34 mm/month for Group 1 and Group 2 respectively. The average amount of change in centroid point to PP distance and U1-SN angle was significantly higher in Group 1 compared to Group 2 (P < 0.001). The average amount of change in U6 to PP distance did not differ significantly between two study groups (P > 0.05).ConclusionThe amount of intrusion is significantly higher in SAD group. Although vertical molar positional change was higher in CIA group than the SAD group, it was not changed significantly in both treatment modalities. SAD group overall had better results and was easier in handling during intrusion.     

A prospective clinical trial of the effects produced by the Connecticut intrusion arch on the maxillary dental arch

ObjectiveTo assess and compare the effects produced in the maxillary dental arch by means of Connecticut intrusion arch (CIA) with or without a cinch back on the distal end of the tube of the first molars.Materials and MethodsThis study included 44 patients with a mean age of 13.1 ± 1.8 years treated for deep bite with a CIA randomly divided into two groups: group 1 (G1), 22 patients with initial mean age of 12.72 ± 1.74 years treated with the CIA in the upper arch without a cinch back on the distal surface of the tube of the first molars, and group 2 (G2), 22 patients with an initial mean age of 13.67 ± 2.03 years treated with the CIA with a cinch back. Lateral cephalograms were available before treatment (T1) and after intrusion of maxillary incisors (T2). The mean treatment period was 5.5 ± 1.45 months. Intragroup and intergroup changes in the maxillary incisor and molar positions were analyzed by paired and independent t-tests associated with the Holm-Bonferroni correction method for multiple comparisons (P < .05).ResultsThere were significant differences between groups in terms of maxillary incisor displacement. The maxillary incisors flared labially (2.17°) and proclined (1.68 mm) in group 1, whereas a palatal inclination (−1.99°) and retroclination (−1.13 mm) was observed in group 2. No significant differences were found for the molar positions between the groups.ConclusionsThe presence or absence of a distal bend in CIA affects incisor tipping and proclination during intrusion mechanics.     

Contextualisation in the revised dual representation theory of PTSD: A response to Pearson and colleagues

Three recent studies (Pearson, 2012 and Pearson et al., 2012) purported to test the revised dual representation theory of posttraumatic stress disorder (Brewin, Gregory, Lipton, & Burgess, 2010) by manipulating the amount of additional information accompanying traumatic stimulus materials and assessing the effect on subsequent intrusive memories. Here we point out that these studies involve a misunderstanding of the meaning of “contextual” within the theory, such that the manipulation would be unlikely to have had the intended effect and the results are ambiguous with respect to the theory. Past and future experimental tests of the theory are discussed.     

Reports

Abstract

In the past, vertical intrusive movement of teeth has been considered difficult and most routine clinical vertical movement of teeth has been confined to extrusion. It has been suggested that attempts at intrusion may result in an increased incidence of root resorption and also in occasional devitalization.

The displacement and resulting stress fields associated with such treatment can be successfully studied using the finite element method. In the case being considered initial movements are known to be small; therefore, the assumption in the study that the material behaves linear-elastically is considered to be reasonable.

This study of vertical tooth movement demonstrated that the maximum cervical margin stress in the periodontal ligament was 0·0046 N/mm², whilst the highest apical stress was 0·00205 N/mm² when intrusive and extrusive forces of 1 Newton were applied to the buccal surface of the crown of a tooth model. These stresses were evaluated in the light of previous studies and found to be within the suggested clinical optimum level. However, the periodontal stress distribution following orthodontic loading within this three-dimensional finite element model was found to be highly complex.     

Management of intruded primary teeth after traumatic injuries

Intrusions occur frequently in the primary dentition. It has been reported that conservative treatment of the intruded primary tooth is preferred if the apex is away from the permanent tooth germ. Conservative treatments include waiting for spontaneous re-eruption, and surgical re-positioning and fixation. Few papers have been published in Japan comparing the prognoses of intruded primary teeth between these two different modes of treatment. Therefore, optimal treatment for intruded primary teeth has been a topic of controversy among clinicians. The aim of this study was to compare the outcomes of intruded primary teeth between these two modes of treatment. Moreover, we examined the issue of treatment of choice for intruded primary teeth. The subjects consisted of 17 children referred to the Hiroshima University Hospital Department of Pediatric Dentistry for the treatment of 21 intruded primary teeth. Fourteen teeth were allowed to spontaneously re-erupt (group W), and 7 teeth were repositioned and fixed (group R). Antibiotic therapy and irrigation were performed in all intruded teeth. Treatment outcomes were evaluated using the following parameters: re-eruption, pathological pulp changes, increased mobility, discoloration, pulp canal obliteration, pathological root resorption, and disturbances of permanent teeth. In group W, root canal treatment or extraction were not performed since re-erupted teeth reveal no signs of infection. On the other hand, in group R, 57% of teeth required endodontic treatment or extracted due to signs of infection. The result showed treatment outcomes in group R were worse than those in group W. Our study indicates that most intruded primary teeth re-erupt with a favorable prognosis. Therefore, observation with irrigation and antibiotic therapy should be the treatment of first choice.     

入侵检测系统研究进展

入侵检测系统是重要的信息安全措施.本文对目前入侵检测系统的研究进展进行了详尽的总结分析,指出了入侵检测系统的最新发展及动态呈现的新特点,重点分析了智能算法的应用、数据融合和报警关联技术的引入、检测对象变化情况及与其它安全技术的协作性;阐述了对入侵检测系统的测试评估方面的最新发展情况以及目前入侵检测标准化的现状;最后,展望了入侵检测系统发展的方向.     

基于差异分析的隐蔽恶意代码检测

隐蔽性恶意程序Rootkit通过篡改系统内核代码与指令,导致操作系统返回虚假的关键系统信息,从而逃避管理员和主机型安全工具的检查.通过分析Rootkit技术的实现原理,包括进程、TCP端口、注册表和文件的隐藏技术,提出了基于差异分析的隐藏行为检测技术.该技术将可信任的系统信息与不可信任的系统信息进行比较,从而获得被隐藏的信息.最终实现了相应的原型系统.与特征码扫描法相比,该检测方法检测在未知和变形Rootkit方面具有明显优势.     

Retrieval-induced forgetting in Alzheimer's disease

It is claimed that Alzheimer's disease (AD) patients show reduced inhibitory processing and this has been put forward as a reason why AD patients make intrusion errors at recall. However, the evidence to date has been equivocal, because non-inhibitory mechanisms can account for the pattern of findings. Recently, however, a paradigm has been developed that is claimed to give a purer measure of inhibitory processing in episodic memory, the retrieval-induced forgetting (RIF) paradigm [Inhibitory Processes in Attention, Memory and Language, Academic Press, San Diego, 1994, p. 265; J. Exp. Psychol.: Learning, Memory Cognition 20 (1994) 1063; Psychol. Rev. 102 (1995) 68]. Thus, we were interested whether AD patients would show a deficit in inhibitory processing using this procedure. Participants studied lists of category cue-exemplar pairs (e.g. fruit-orange) then practised retrieval for a subset of items from a subset of categories before taking a final memory test for all studied items. As in previous work, inhibition was measured as the difference between final memory performance for unpractised items from practised categories, and unpractised items from unpractised categories. The results show that AD patients showed normal levels of inhibition with both tests of cued recall and category generation (CG). This suggests that a deficit in inhibitory processes during retrieval is not behind the high levels of intrusion errors made in recall in AD.     

基于威胁度的动态报警管理研究

IDS目前的主要问题之一是过高的误报率,这一方面给管理员增加了繁重的工作负担,从而使其可能忽视了系统中真正需要处理的关键攻击事件;另一方面,过高的误报率使得自动入侵响应,比如与防火墙联动,不能很好地执行下去.针对这个问题,提出了基于威胁度的动态报警管理TDAM模型,它通过对系统环境的感知分析报警信息,确定其威胁度.通过实验,可以得出TDAM框架能够比较好地进行报警评价、管理.