Detection of toluene dissolved in water by using PCS fibers excited by an inclined collimated beam

This paper reports results on the sensitivity of straight polymer-clad silica (PCS) detection fibers with short sensing parts coated with polysiloxane polymers to toluene dissolved in water. The detection was based on refractive index changes of the polymers induced by the penetration of toluene into them. These changes were detected by measuring changes of the output power from the detection fibers excited by an inclined collimated beam at 630 nm.

Commercially available Cablelite 950-701 and two types of polymethylphenylsiloxane polymers developed at the Romanian Academy were tested as materials for the fabrication of the detection part in the fiber cladding. These parts were prepared by application of polymer layers onto a bare silica core by a dip-coating technique. Layers with thicknesses of about 20 μm were prepared.

Examples of angular distributions of the output power determined for the detection polymers in contact with air, time response curves measured with the detection parts brought into contact with aqueous solutions of toluene under different hydrodynamic conditions, and sensitivity curves are shown in the paper. The best detection limit of about 10 mg/l of toluene, reversibility and linearity of the fiber response in a range 0–100 mg/l could be achieved with fibers coated with Cablelite 950-701 polymer.     

Stereotype Threat Might Explain the Black-White Test-Score Difference.

Comments on an article by Paul Sackett, Chaitra Hardison and Michael Cullen entitled On Interpreting Stereotype Threat as Accounting for African American-White Differences on Cognitive Tests (see record 2004-10043-001). In their correction of the ostensibly widespread misinterpretation of Steele and Aronson's (see record 2000-16592-021) seminal study of the effects of stereotype threat on intellectual test scores, Sackett, Hardison, and Cullen expressed dismay and puzzlement that so many erudite people consistently have gone so far astray in their understanding of this matter. The gist of Sackett et al.'s correction was that interpreters of Steele and Aronson's results have ignored the researchers' statistical adjustment of their dependent measure for SAT scores and, consequently, have wrongly concluded that racial-group (i.e., Black-White) differences in test scores disappear when stereotype threat is removed. In their justification for this much needed clarification, Sackett et al. (2004) implied that the interpretation that stereotype threat explains the Black-White test score disparity is not plausible. Yet whether or not the construct of stereotype threat generally can account for the Black-White test-score disparity was not the question that was directly addressed by either Steele and Aronson's (1995) original study or Sackett et al.'s (2004) critique of it. It appears that Sackett et al. (2004), as well as the many people responsible for the allegedly faulty interpretation, essentially want an answer to the question, What causes or explains racial-group difference(s) in Black-White test scores? This question logically flows from (a) reviews demonstrating the chronic resistance of these differences to psychoeducational interventions, (b) general recognition that racial-group membership cannot cause behavior (e.g., differences in test scores), as well as (c) acknowledgment that use of test scores for high-stakes decision making under prevailing circumstances amounts to "racial profiling" condoned by society and the law. Therefore, if stereotype threat or analogous race or culture-related psychological constructs could be shown to account for the Black-White testscore disparity, then society would be relieved of the burden of unfair testing practices, and Sackett et al. would be relieved of the burden of "heading off future interpretive errors" (p. 11) regarding Steele and Aronson's results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stereotype Threat and the Social and Scientific Contexts of the Race Achievement Gap.

Comments on an article by Paul Sackett, Chaitra Hardison and Michael Cullen entitled On Interpreting Stereotype Threat as Accounting for African American-White Differences on Cognitive Tests (see record 2004-10043-001). In their article, Sackett, Hardison, and Cullen (see record 2000-16592-021) critiqued misrepresentations of the original stereotype threat findings presented by Steele and Aronson. They criticized representations of the research that suggest that stereotype threat explains all the racial achievement gap in academic performance when, in fact, the original studies statistically equated the ability of Black students and White students by using SAT scores as a covariate. As Sackett et al. acknowledged, Steele and Aronson did not claim that stereotype threat explains all the racial achievement gap, though as they suggested in their critique, it may have been a claim made implicitly and even explicitly in some media and textbook coverage of the work. The authors of this comment wish to make three points that Sackett and colleagues did not make. These points highlight the social and scientific contexts in which Sackett et al.'s critical commentary, and stereotype threat research in general, can be interpreted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On Interpreting Research on Stereotype Threat and Test Performance.

The authors comment on the comments (see records 2005-03019-016; 2005-03019-017; 2005-03019-018) made on their original article entitled On Interpreting Stereotype Threat as Accounting for African American-White Differences on Cognitive Tests (see record 2004-10043-001). The authors welcome the thoughtful insights of Wicherts, Helms, and Cohen and Sherman, and they hope that these comments stimulate further critical analysis of methodological issues associated with stereotype threat research. The authors do not dispute that stereotype threat is a real phenomenon or that it remains a potentially important contributor to the racial achievement gap. They encourage researchers to continue their efforts to determine what role stereotype threat plays in contributing to that gap, especially in real-world testing situations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Internal sense of direction and landmark use in pigeons (Columba livia).

The relative importance of an internal sense of direction based on inertial cues and landmark piloting for small-scale navigation by White King pigeons (Columba livia) was investigated in an arena search task. Two groups of pigeons differed in whether they had access to visual cues outside the arena. In Experiment 1, pigeons were given experience with 2 different entrances and all pigeons transferred accurate searching to novel entrances. Explicit disorientation before entering did not affect accuracy. In Experiments 2-4, landmarks and inertial cues were put in conflict or tested 1 at a time. Pigeons tended to follow the landmarks in a conflict situation but could use an internal sense of direction to search when landmarks were unavailable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

White Selves: Conceptualizing and Measuring a Dominant-Group Identity.

This article addresses the nature and measurement of White racial identity. White identification is conceptualized as an automatic association between the self and the White ingroup; this association is fostered through social exposure to non-Whites and serves to link self- and ingroup evaluations. Four studies validated a measure of White identification against criteria derived from this model. In Study 1, the White Identity Centrality Implicit Association Test (WICIAT) predicted response latencies in a task gauging self-ingroup merging. In Study 2, the WICIAT correlated with census data tapping exposure to non-Whites. In Studies 3 and 4, the WICIAT predicted phenomena associated with the linking of self- and ingroup evaluations: identity-related biases in intergroup categorization (Study 3) and self-evaluative emotional reactions to ingroup transgressions (Study 4). Together, the findings shed light on the antecedents and consequences of White identity, an often-neglected individual difference construct. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

氮锌复合作用对白三叶草生长、氮锌吸收和生理生化特性的影响

采用砂培试验方法,系统研究了不同水平氮锌配施对白三叶生长和生理生化特性的影响。结果表明,在缺锌条件下,随施氮水平增加,白三叶氮代谢和清除活性氧的能力、IAA、GAs含量下降,ABA、MDA含量增加,氮锌配施对生长和元素吸收表现为拮抗效应;在足量供锌条件下,与低量供氮相比,中量供氮时,白三叶氮代谢和清除活性氧的能力、IAA、GAs含量增加,ABA、MDA含量下降,氮锌配施对生长和元素吸收表现为协同效应。当高量氮时,氮锌配施则表现为拮抗效应。在判断氮锌复合作用类型时,应区分生长量变化引起的“浓缩效应”和“稀释效应”,应以生长量和吸收量变化来确定氮锌复合作用的类型。     

陶艺灯具的黑白文化

面对竞争日趋激烈的陶艺灯具市场,设计师要善于把握独特的陶艺灯具设计风格,并以此作为重点竞争手段,才能赢得消费者市场。从黑白色韵味的陶艺灯具造型中,归纳总结黑白文化所特有的视觉对于营造独特陶艺灯具造型设计风格的决定意义,分别从明度对比、轻重对比、性格对比、文化对比、空间对比、阴阳对比、词义对比、历史性与未来性对比八个方面分别阐述黑白文化陶艺灯具视觉构成的特有魅力。     

基于精细化残差U-Net的新生儿局灶性脑白质损伤分割模型

针对新生儿局灶性脑白质损伤的病灶区域小而样本差异大导致的检测与分割病灶较为困难的问题,提出一种精细化深度残差U-Net模型,以对病灶进行精细的语义分割。首先,把核磁共振（MRI）图像裁剪成较小的图像块;其次,利用残差U-Net提取出每个图像块不同层次的深度特征;然后,将特征进行融合并输出每个图像块的病灶分布概率图;最后,由全连接条件随机场对拼接后的概率图进行优化得到最终的分割结果。在某合作医院提供的数据集上的评估结果显示,在仅使用T1序列单模态数据的情况下,该模型在分割新生儿局灶性脑白质损伤时,病灶边缘的分割精度得到提高,且模型抗干扰能力较好。该模型的Dice相似性系数达到了62.51%,敏感度达到69.76%,特异性达到99.96%,修正的Hausdorff距离降低到33.67。