One Mouse per Child: interpersonal computer for individual arithmetic practice

Single Display Groupware (SDG) allows multiple people in the same physical space to interact simultaneously over a single communal display through individual input devices that work on the same machine. The aim of this paper is to show how SDG can be used to improve the way resources are used in schools, allowing students to work simultaneously on individual problems at a shared display, and achieve personalized learning with individual feedback within different cultural contexts. We used computational fluency to apply our concept of ‘One Mouse per Child’. It consists of a participatory approach that makes use of personal feedback on an interpersonal computer for the whole classroom. This allows for N simultaneous intelligent tutoring systems, where each child advances at his or her own pace, both within a lecture and throughout the curricular units. Each student must solve a series of mathematical exercises, generated according to his or her performance through a set of pedagogical rules incorporated into the system. In this process, the teacher has an active mediating role, intervening when students require attention. Two exploratory studies were performed. The first study was a multicultural experience between two such distanced socio‐economic realities as Chile and India. It showed us that even in different environmental conditions, it is possible to implement this technology with minimal equipment (i.e. a computer, a projector, and one mouse per child). The second study was carried out in a third grade class in a low‐income school in Santiago de Chile. The students were asked to solve mainly addition exercises. We established statistically relevant results and observed that the software proved most beneficial for the students with the lowest initial results. This happens because the system adapts to the students' needs, reinforcing the content they most need to work on, thus generating a personalized learning process.     

Interval timing accuracy and scalar timing in C57BL/6 mice.

In many species, interval timing behavior is accurate—appropriate estimated durations—and scalar—errors vary linearly with estimated durations. Whereas accuracy has been previously examined, scalar timing has not been clearly demonstrated in house mice (Mus musculus), raising concerns about mouse models of human disease. The authors estimated timing accuracy and precision in C57BL/6 mice, the most used background strain for genetic models of human disease, in a peak-interval procedure with multiple intervals. Both when timing 2 intervals (Experiment 1) or 3 intervals (Experiment 2), C57BL/6 mice demonstrated varying degrees of timing accuracy. An important finding was that, both at the individual and group levels, their precision varied linearly with the subjective estimated duration. Further evidence for scalar timing was obtained using an intraclass correlation statistic. This is the first report of consistent, reliable scalar timing in a sizable sample of house mice, thus validating the peak-interval procedure as a valuable technique, the intraclass correlation statistic as a powerful test of the scalar property, and the C57BL/6 strain as a suitable background for behavioral investigations of genetically engineered mice modeling disorders of interval timing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of loud noise exposure on mouse myocardium: a comparison with the rat

Loud noise is an environmental stressor of everyday life, which affects different organs and apparati, in particular the cardiovascular system. We have already reported that noise exposure produces significant alterations in the rat myocardium, consisting of mitochondrial damage, which is evident as lysis of the cristae and dilution of the matrix. Since there are high similarities between mouse and human species, the aim of our study was to investigate the effects of acute noise exposure on the mouse heart. We found that noise exposure affects mouse myocardium at similar subcellular sites to those already described in the rat; nonetheless, quantitative analysis of the percentage of altered mitochondria in both species disclosed a clear difference between mouse and rat myocardium, which strongly suggests a different sensitivity to noise stimulus. We hypothesize that the species differences on the extent of myocardial alterations here observed might be due to the zonal pattern of cardiac noradrenergic receptors, which should be the final effectors for noise-induced myocardial changes.     

Why are eye mice unpopular? A detailed comparison of head and eye controlled assistive technology pointing devices

This paper examines and compares the usability problems associated with eye-based and head-based assistive technology pointing devices when used for direct manipulation on a standard graphical user interface. It discusses and examines the pros and cons of eye-based pointing in comparison to the established assistive technology technique of head-based pointing and illustrates the usability factors responsible for the apparent low usage or unpopularity of eye-based pointing. It shows that user experience and target size on the interface are the predominant factors affecting eye-based pointing and suggests that these could be overcome to enable eye-based pointing to be a viable and available direct manipulation interaction technique for the motor-disabled community.     

鼠笼破碎机的设计与改进

分析原鼠笼破碎机在设计上和生产中存在的问题，通过观察与计算，找出原因并提出改造措施。根据扩产要求，对鼠笼破碎机的结构和各项技术指标进行设计分析，指出影响鼠笼破碎机产能的主要因素，总结出鼠笼破碎机产能的估算公式。     

Enhanced recognition memory following glycine transporter 1 deletion in forebrain neurons.

Selective deletion of glycine transporter 1 (GlyT1) in forebrain neurons enhances N-methyl-D-aspartate receptor (NMDAR)-dependent neurotransmission and facilitates associative learning. These effects are attributable to increases in extracellular glycine availability in forebrain neurons due to reduced glycine re-uptake. Using a forebrain- and neuron-specific GlyT1-knockout mouse line (CamKIIαCre; GlyT1tm1.2fl/fI), the authors investigated whether this molecular intervention can affect recognition memory. In a spontaneous object recognition memory test, enhanced preference for a novel object was demonstrated in mutant mice relative to littermate control subjects at a retention interval of 2 hr, but not at 2 min. Furthermore, mutants were responsive to a switch in the relative spatial positions of objects, whereas control subjects were not. These potential procognitive effects were demonstrated against a lack of difference in contextual novelty detection: Mutant and control subjects showed equivalent preference for a novel over a familiar context. Results therefore extend the possible range of potential promnesic effects of specific forebrain neuronal GlyT1 deletion from associative learning to recognition memory and further support the possibility that mnemonic functions can be enhanced by reducing GlyT1 function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imaging of mouse experimental melanoma in vivo and ex vivo by combination of confocal and nonlinear microscopy

We investigated possibilities of the combination of the one- and two-photon excitation microscopy for examination of the experimental melanoma tissue in vivo, in mice under general anesthesia, and ex vivo on freshly harvested specimens. Our aim was to obtain sufficiently informative images of unstained tumor tissues and their modifications after hyperthermia treatment. The mouse experimental melanoma structure was studied and compared with normal tissue from the same animal by using confocal and nonlinear microscopy techniques based on (i) one-photon excitation (1PE) fluorescence, (ii) 1PE reflectance, (iii) second harmonic generation imaging, and (iv) two-photon excitation autofluorescence. We checked different spectral conditions and other settings of image acquisition, as well as combinations of the above imaging modalities, to fully exploit the potential of these techniques in the evaluation of treated and untreated cancer tissue morphology. Our approach enabled to reveal the collagen fiber network in relation with the other tissues, and to identify invasive tumor cells. It also proved to be useful for the examination of interrelationships between functional and morphological aspects based on optical properties of the tissues, especially in studies of changes between the tumor and control tissue, as well as changes induced by physical treatments, e.g., delivery of microwave hyperthermia treatment. These differences were also evaluated quantitatively, when we found out that the maximum Euler–Poincaré characteristic reflects well the melanoma morphological structure. The results showed that the proposed investigative approach could be suitable also for a direct evaluation of tissue modifications induced by clinical interventions. Microsc. Res. Tech., 2009. © 2009 Wiley-Liss, Inc.     

Evidence for social anxiety and impaired social cognition in a mouse model of fragile X syndrome.

This study assessed social behavior in a mouse model of Fragile X syndrome (FXS), the Fmr1 tm1Cgr or Fmr1 "knockout" (KO) mouse. Both the KO and wild-type (WT) mice preferred to be near a novel conspecific than to be alone. However, during the initial interaction with a novel conspecific, (1) a greater proportion of the KO mice exhibited high levels of grooming; and (2) the average duration of nose contact with the stimulus mouse was significantly shorter for the KO mice, both indicative of increased arousal and/or anxiety. Both groups exhibited a robust novelty preference when the novel animal was a "preferred" mouse. However, when the novel mouse was a "nonpreferred" animal, both groups showed a diminished novelty preference but this effect was more pronounced for the WT mice. This blunted negative reaction of the KO mice to a nonpreferred animal may indicate that they were less proficient than controls in distinguishing between positive and negative social interactions. These findings provide support for the use of this animal model to study the autistic features of FXS and autism spectrum disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of Long-term Intake of Rare Earth in Drinking Water on Trace Elements in Brains of Mice

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鼠标上下盖塑料熔体流动平衡分析

借助Moldflow分析软件对鼠标上下盖注射成型过程进行熔体的流动平衡分析,通过不断逼近的迭代计算和调整浇注系统中分流道的直径,达到平衡熔体流动的目的,保证多型腔模具成型的塑件具有良好的质量,缩短了模具设计周期。