绿球藻目的几个中国新记录属种

6个生境比较特殊而有趣的绿球藻目物种首次在我国发现,它们分别是生于土壤的香喇网绿藻(Dictyochloris fragrans Vischer ex Start),寄生于眼子菜叶片的浮萍绿点藻(Chlorchytrium lemmae Cohn.),气生种类—生长在樟树皮上的分层胶囊藻(Gloeocystis polydermatica(Kutz.) Hindak),与真菌共生形成地衣的土著共球藻(Trebouxia aboricola de Puymaly)和团集共球藻(Trebouscia glom

吗啡给药及戒断期间大鼠眶额叶脑区功能活动特征户外环境下自由活动猕猴顶叶及海马神经元单位放电的胞外记录方法

已有的研究表明，眶额叶在解剖上与现在已知的药物滥用相关的脑区是紧密联系在一起的。例如，眶额叶在药物滥用和强迫性重复行为中起作用，且随着脑成像技术的应用，越来越多的证据表明眶额叶参与了药物滥用。但是我们并不了解在阿片给药和戒断期间眶额叶脑区活动是如何变化的。因此，我们在实验中采用了Mn2+增强的核磁共振成像（Manganese-enhanced magnetic resonance　imaging，MEMRI，4.7T）技术和脑电（EEG）记录的方法，以研究大鼠眶额叶在给与阿片类药物（盐酸吗啡）以及戒断过程中的动态变化。 MEMRI是一种近年才发展起来的新型技术。研究表明，Mn2+是Ca2+的类似物，可以通过Ca2+通道进入兴奋性的神经元里面并结合到胞内的蛋白质和核酸上的Ca2+和Mg2+结合位点上 (MILDVAN and COHN, 1963; EISINGER et al., 1965)。另外，Mn2+的顺磁性也为它成为核磁共振成像的造影剂提供了前提条件。可是成功应用MEMRI的前提就是要在适当的时间把合适剂量的Mn2+传递到靶点上。因此，Mn2+在注射到靶点后，是否能够在有效的时间内反映大脑活动的变化就成为一个非常重要并且在技术上较为棘手的问题。在给实验大鼠脑区微量注射Mn2+（80mMol/L，200nl）的同时，通过微量注射兴奋性神经递质谷氨酸（Glu 0.5mM/L）或抑制性递质γ-aminobutyric acid（GABA 0.5M/L）以改变靶点神经元兴奋性的方法，检测Mn2+能否反映脑区的活动变化。另外，我们随机选取实验动物，分别在注射Mn2+ 3小时、5小时和8小时后对三组大鼠（n=5）进行10％福尔马林灌流，并且通过观察大鼠眶额叶脑区Mn2+强度的变化来研究最佳的灌流时间。我们的实验结果表明，Mn2++Glu组的右侧脑区/左侧脑区的Mn2+亮度比Mn2+空白对照组增加了20％（p=0.016, student t-test, *p <0.05），也远大于Mn2++GABA组（p=0.047, *p<0.05）。结果表明，当神经元被兴奋的时候，较多的Mn2+可以通过Ca2+通道进入兴奋的神经元内，使得Mn2+的成像亮度增加。由于Mn2+成像亮度的增加可以反映神经元的兴奋活动，因此可以显示出靶点区的脑活动。另外，在研究灌流时间对Mn2+亮度影响的实验中发现，注射Mn2+ 5小时后灌流得到的信噪比分别比注射Mn2+3小时（p＝0.055）和8小时（p=0.004，*p<0.05）高出24％和32％。总之，我们采用微量注射Mn2+（80mM/L,200nl）后5小时用10%福尔马林心脏灌流的方法获得了较好的结果。另外在试验中我们首先观测了大鼠吗啡戒断后的行为学指标和检测大鼠戒断后条件化位置偏好的程度。实验结果表明大鼠可以建立非常明显的条件化位置偏好，但在湿狗抖等行为学指标上无明显症状。这说明大鼠对于吗啡(10mg/kg, 一天两次，持续12天)形成了明显的心理依赖而无明显的生理依赖。此外，MEMRI的结果表明，在吗啡给药的第1天和第6天，大鼠眶额叶的Mn2+强度与空白对照组相比有显著的降低( one-way ANOVA, Post Hoc Dunnett’s C Tests), F (6,28)=7.242, P<0.001)；而在戒断第3天又恢复到正常水平，在戒断第5天和第7天Mn2+强度跟空白对照组相比没有显著性差别(one-way ANOVA, *p<0.05)。脑电（EEG）的结果表明，急性吗啡诱导的gamma波段的EEG显著降低(Two-way ANOVA, F(1,10)=13.626,p=0.006)。然而在戒断第1天gamma波段的EEG与空白对照组相比是增加的。在戒断第3天和戒断第5天，gamma波段的EEG与空白对照组相比也有显著性增强。以上研究结果表明：大鼠眶额叶脑区的动态变化与整个吗啡给药和戒断过程是密切相关的；此外，MEMRI在探讨药物滥用以及成瘾等机制上有很大的应用前景。

Image Ratio Features for Facial Expression Recognition Application

Video-based facial expression recognition is a challenging problem in computer vision and human-computer interaction. To target this problem, texture features have been extracted and widely used, because they can capture image intensity changes raised by skin deformation. However, existing texture features encounter problems with albedo and lighting variations. To solve both problems, we propose a new texture feature called image ratio features. Compared with previously proposed texture features, e. g., high gradient component features, image ratio features are more robust to albedo and lighting variations. In addition, to further improve facial expression recognition accuracy based on image ratio features, we combine image ratio features with facial animation parameters (FAPs), which describe the geometric motions of facial feature points. The performance evaluation is based on the Carnegie Mellon University Cohn-Kanade database, our own database, and the Japanese Female Facial Expression database. Experimental results show that the proposed image ratio feature is more robust to albedo and lighting variations, and the combination of image ratio features and FAPs outperforms each feature alone. In addition, we study asymmetric facial expressions based on our own facial expression database and demonstrate the superior performance of our combined expression recognition system.

Neural Network Exploration Using Optimal Experiment Design

We consider the question "How should one act when the only goal is to learn as much as possible?" Building on the theoretical results of Fedorov [1972] and MacKay [1992], we apply techniques from Optimal Experiment Design (OED) to guide the query/action selection of a neural network learner. We demonstrate that these techniques allow the learner to minimize its generalization error by exploring its domain efficiently and completely. We conclude that, while not a panacea, OED-based query/action has much to offer, especially in domains where its high computational costs can be tolerated.

Minimizing Statistical Bias with Queries

I describe an exploration criterion that attempts to minimize the error of a learner by minimizing its estimated squared bias. I describe experiments with locally-weighted regression on two simple kinematics problems, and observe that this "bias-only" approach outperforms the more common "variance-only" exploration approach, even in the presence of noise.

The Jews in the Modern World : A History Since 1750

Rubinstein, William, et al., The Jews in the Modern World: A History Since 1750 (London: Hodder and Arnold, 2002), pp.xiv+449 RAE2008

Alien gosd in the new epics: Noah remythologised through the ancient astronaut hypothesis in Abel's Montagut's "La gesta d'Utnoa"

Modern scientific world-view has undermined traditional myths, the functional survival of which seems to depend today in the West on a positivist justification. This would place them in the field of real History, through their study and revitalization by pseudoscientific disciplines such as the Atlantis and the ancient astronaut hypotheses. These have inspired new epic poems in (regular) verse that combine classic and/or biblical myths with a (pseudo)scientific modern world-view. For example, the critical rewriting of Noah’s myth by using the ancient astronaut hypothesis as a fictional device to produce a contemporary kind of plausibility allowed Abel Montagut to renew epic poetry, updating it also by adopting science fiction chronotopes in order to structure his fictional construction and to generate a high ethical sense for our time. Thus, his Poemo de Utnoa (1993) / La gesta d’Utnoa (1996), which has become a major classic of the literature in Esperanto thanks to its original version in this language, is a landmark of both science fiction and neo-biblical epics. This poem is written from a secular and purely literary perspective.

Dogs in the paradise: The influence of the cynical philosophy in the construction of the myth of the good savage

This paper studies the influence of cynic philosophy in the construction of the myth of the good savage. In the first part it studies the importance of cynicism in the XVI century and how the cynic influence of Erasmus, More and Montaigne was fundamental to the way that Europe approached the American indigenous. In the second part it studies the cynic motives that could have influenced in the construction of the myth of the good savage.

The autobiographical you: letters in the gendered politics of the labour movement.

In this article, I consider the importance of epistolary narratives in the interface of autobiography and politics. In doing this, I read the letters of Fannia Mary Cohn, a Jewish immigrant worker, trade union activist and ardent labour organizer in the garment industry in the USA in the first half of the twentieth century. Cohn was a prolific writer and political activist and left a rich body of labour literature, but never wrote an autobiography or a diary or journal. It is in her letters to her comrades and friends in the labour movement that short autobiographical stories erupt and it is on such stories across her correspondence that this article focuses. The analysis is informed by Hannah Arendt’s theorization of narratives in their interrelation with politics and history. Drawing on a rich body of feminist literature around the relational self, what I argue is that an Arendtian reading of epistolary narratives is a useful analytical tool in understanding gendered politics in the diverse histories of the labour movement.

A Orquestra Oculta, os estudos da consciência e a literatura

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Estudos Portugueses

Pourquoi nous avons besoin de la critique?

Fundação para a Ciência e a Tecnologia (FCT), Fundação Millennium bcp

Active Learning with Statistical Models

For many types of learners one can compute the statistically 'optimal' way to select data. We review how these techniques have been used with feedforward neural networks. We then show how the same principles may be used to select data for two alternative, statistically-based learning architectures: mixtures of Gaussians and locally weighted regression. While the techniques for neural networks are expensive and approximate, the techniques for mixtures of Gaussians and locally weighted regression are both efficient and accurate.

Cirugía abierta como manejo de enfermedad varicosa pélvica

El dolor pélvico crónico es un motivo frecuente de consulta, que está presente hasta en un 40% de las mujeres, y que afecta de manera considerable su calidad de vida. El síndrome de congestión pélvica asociado a varices constituye un factor etiológico de esta patología; sin embargo, existe poca evidencia que describa la eficacia y seguridad de la técnica quirúrgica abierta. Este estudio evalúa los resultados clínicos de la cirugía abierta para el manejo de las várices pélvicas. Metodología: se realizó un estudio descriptivo de corte transversal con 94 pacientes con varices gonadales, sometidas a cirugía abierta. Se evaluaron los hallazgos del método diagnóstico, los hallazgos intraoperatorios, y la evolución post operatoria. Resultados: El 85% de las pacientes presentó reflujo bilateral, y 15% reflujo unilateral. Más del 70% reportó presencia de dolor pélvico mayor a 6 meses, dispareunia, dismenorrea, y síntomas urinarios. Se demostraron diferencias estadísticamente significativas cuando se compararon los diámetros reportados en el dúplex, con los medidos intra operatoriamente, específicamente en las mediciones de la vena gonadal derecha, tanto en pacientes con reflujo unilateral (p=0.022) como bilateral (p= 0.017). El 92% de las pacientes presentó mejoría de los síntomas posterior al tratamiento quirúrgico. Conclusiones: La ligadura de las venas ováricas por cirugía abierta es una alternativa terapéutica para el tratamiento de las várices pélvicas, con resultados que demuestran mejoría sintomática importante. El dúplex constituye un método diagnóstico útil, aunque el diámetro de las venas gonadales puede ser subestimado. Palabras clave: varices gonadales, dolor pélvico crónico, síndrome de congestión, pélvica, cirugía abierta

Dinámica del anillo mitral en pacientes con insuficiencia mitral isquemica

OBJETIVOS: Describir y comparar los cambios dinámicos de la geometría del anillo mitral durante todo el ciclo cardiaco en pacientes con insuficiencia mitral isquémica y pacientes con válvula mitral normal. MATERIALES Y MÉTODOS: Los estudios ecocardiográficos analizados fueron 37, 23 con insuficiencia mitral isquémica y 14 con válvula mitral normal. La reconstrucción del anillo se realizó en la estación de trabajo Xcelera (Philips Medial Systems) mediante la herramienta de análisis mitral (MVQ), en 5 momentos del ciclo cardiaco: Comienzo de Sístole, Mitad de Sístole, Final de Sístole, Mitad de Diástole y Final de Diástole. RESULTADOS: El anillo del grupo control, fue más dinámico, con sus menores dimensiones al final de la diástole, presentando incremento progresivo durante la sístole. Los cambios en el perímetro y el área, fueron significativos entre el comienzo y mitad de la sístole (p:0.087 y p: 0.055). En el grupo con insuficiencia mitral isquémica, el anillo fue más estático. Todas las dimensiones en este grupo, fueron mayores en los cinco momentos del ciclo cardiaco. (p < 0.1). El anillo también fue más plano, con un índice morfológico anular menor al del grupo control (p:0.087). DISCUSIÓN Y CONCLUSIONES: En pacientes sin insuficiencia mitral, el anillo es una estructura dinámica. Durante la sístole, las menores dimensiones se produjeron al comienzo de este periodo y la conformación en silla de montar se mantuvo, protegiendo contra la insuficiencia mitral. El anillo del grupo con insuficiencia mitral fue más estático y plano, perdiendo los mecanismos protectores.