Adenosine A2A receptor modulation of hippocampal CA3-CA1 synapse plasticity during associative learning in behaving mice

© 2009 Nature Publishing Group All rights reservedPrevious in vitro studies have characterized the electrophysiological and molecular signaling pathways of adenosine tonic modulation on long-lasting synaptic plasticity events, particularly for hippocampal long-term potentiation(LTP). However, it remains to be elucidated whether the long-term changes produced by endogenous adenosine in the efficiency of synapses are related to those required for learning and memory formation. Our goal was to understand how endogenous activation of adenosine excitatory A2A receptors modulates the associative learning evolution in conscious behaving mice. We have studied here the effects of the application of a highly selective A2A receptor antagonist, SCH58261, upon a well-known associative learning paradigm - classical eyeblink conditioning. We used a trace paradigm, with a tone as the conditioned stimulus (CS) and an electric shock presented to the supraorbital nerve as the unconditioned stimulus(US). A single electrical pulse was presented to the Schaffer collateral–commissural pathway to evoke field EPSPs (fEPSPs) in the pyramidal CA1 area during the CS–US interval. In vehicle-injected animals, there was a progressive increase in the percentage of conditioning responses (CRs) and in the slope of fEPSPs through conditioning sessions, an effect that was completely prevented (and lost) in SCH58261 (0.5 mg/kg, i.p.)-injected animals. Moreover, experimentally evoked LTP was impaired in SCH58261- injected mice. In conclusion, the endogenous activation of adenosine A2A receptors plays a pivotal effect on the associative learning process and its relevant hippocampal circuits, including activity-dependent changes at the CA3-CA1 synapse.This study was supported by grants from the Spanish Ministry of Education and Research (BFU2005-01024 and BFU2005-02512), Spanish Junta de Andalucía (BIO-122 and CVI-02487), and the Fundación Conocimiento y Cultura of the Pablo de Olavide University (Seville, Spain).B. Fontinha was in receipt of a studentship from a project grant (POCI/SAU-NEU/56332/2004) supported by Fundação para a Ciência e Tecnologia (FCT, Portugal), and of an STSM from Cost B30 concerted action of the EU

A Review of Discourse Analysis in Literacy Research: Equitable Access

This review represents research employing discourse analysis conducted by scholars interested in literacy issues in education across the age span—preschool to adult—during the last 10 years. Drawing from more than 300 studies, we discerned that a common theme was understanding how the literacy education of all students can be successfully accomplished. We organized the review into two complementary sections. The first section highlights discourse analytic approaches taken to investigate: Whose literacies count? Which literacies count? The second section explains the contributions the studies made organized according to five questions: What are literate identities, how are they constructed, and by whom? How are disciplinary knowledges, discourses, and identities constructed? How can schools provide students with access to school‐based literacies? What are the shifting roles of literacy teachers and learners within and outside of school? How does discourse analysis research address movement within and across literacy sites and practices in a contemporary, globalized, and increasingly digitally influenced world? تلخيص البحث: تمثل هذه المراجعة الأبحاث التي يوجد فيها تحليل الخطاب الذي قام به الباحثون المهتمون بشؤون تعلم القراءة والكتابة في التعليم عبر الأعمار—من الروضة حتى بالغ سن الرشد—في السنوات العشرة الماضية. لقد حددنا موضوعاً مشتركاً من استجماع أكثر من 300 دراسة وهو الطريقة التي قد يتم فيها تعليم القراءة والكتابة لجميع الطلاب بالنجاح. وقد نظمنا المراجعة في قسمين متكاملين الأول يسلط الضوء على طرق الخطاب التحليلية المأخوذة للتحقيق في: لمن معارف القراءة والكتابة التي نحتاج إلى أخذها بعين الاعتبار؟ وأية معارف من هذه يجب الأخذ في الحسبان؟ والقسم الثاني يشرح مساهمات الدراسات المندرجة تحت الأصناف المبنية على خمسة أسئلة: ما هي هويات معرفة القراءة والكتابة وكيف يتم تشكيلها ومن يشكلها؟ وكيف يتم تشكيل المعارف الدراسية والخطابية والهوية؟ وكيف تستطيع المدارس أن توفر الطلاب بوسيلة للمعارف القائمة في المدرسة؟ ما هي الأدوار المتغيرة لمعلمي القراءة والكتابة وطلابهم داخل المدرسة وخارجها؟ وكيف يعالج التحليل الخطابي الحركات في مواقع القراءة والكتابة وعبرها وكذلك الممارسات التي تتم في عالم معاصر عولمي فيه يزداد التأثير الرقمي؟ 本文旨在阐述过去10年期间，学者致力于不同学龄（由学前以至成人）的读写教育问题研究时所使用的语篇分析方法。作者从300多个研究里整理出一个共通的主题，就是去理解如何使到所有学生的读写教育取得成功。本文献综述是由两个互补的章节组成。第一节重点介绍研究调查所采用的两个语篇分析的处理方法：是谁的读写文化有重要意义？哪些读写文化有重要意义？第二节根据五个问题来阐釋这些研究的贡献：1.有读写文化的人的身份认同，所指的是什么？是怎样建构而成的？由谁所建构而成的？2.各种学科知识、话语及身份认同是如何建构而成的？3.学校如何为学生提供获取校本读写文化知识的门路？4.读写教学教师与学生在校内及校外在角色上有什么转移？5.在当前全球化和日益受数码化影响的世界中，语篇分析研究如何处理流动于各种写文化网站以内及之间的文化信息及各种文化实践的问题？ Cet état de la question présente l'analyse du discours dans les recherches des chercheurs qui s'intéressent aux questions de littératie en éducation— du niveau préscolaire à l'adulte — au cours des dix dernières années. En nous basant sur plus de 300 études, une préoccupation commune nous est apparue qui est de comprendre comment l'enseignement de la littératie peut permettre à tous les élèves de réussir. Nous avons organisé l'état de la question en deux parties complémentaires. La première partie s'intéresse au discours des approches analytiques réalisées pour étudier les questions suivantes: prendre en compte les littératies de qui ? prendre en compte quelles littératies? La seconde partie explique ce qu'ont apporté les études effectuées en réponse à cinq questions: que sont les identités lettrées ? comment sont‐elles construites, et par qui ? Comment sont construits les avoirs disciplinaires, les discours, et les identités ? Comment les écoles fournissent‐elles aux élèves un accès aux littératies basées sur l'école ? Quels sont les changements de rôles des professeurs de littératie et des apprenants dans l'école et hors de celle‐ci ? Comment le discours de la recherche analysé prend‐il en compte le mouvement au sein et au travers des sites de littératie et des pratiques dans un monde contemporain globalisé et de plus en plus influencé par l'informatique. В этом обзоре представлены исследования, проведенные на протяжении последних десяти лет с помощью дискурс‐анализа и посвященные проблемам развития грамотности людей разного возраста – от дошкольников до взрослых. Общая тема для более чем трехсот рассмотренных авторами источников: как добиться успеха в становлении грамотности? Обзор состоит из двух взаимодополняющих разделов. В первом описаны подходы к анализу дискурса, которые помогают понять, что принимается за образцы грамотности и кто может им соответствовать. Во втором разделе результаты исследований рассмотрены согласно пяти категориям: Как человек осознает себя в плане грамотности, на чем и кем строится эта идентичность? Как конструируется предметное или дисциплинарное знание, дискурс и идентичность? Как может школа дать учащимся доступ к школьной академической грамотности? В чем состоят и как меняются роли преподавателей грамотности и учащихся в стенах школы и за ее пределами? Как исследования дискурс‐анализа отражают перемещения участников дискурса в реальном и виртуальном пространстве в современном глобализированном мире? Este repaso presenta investigación que ha sido llevada a cabo usando análisis del discurso por estudiosos interesados en cuestiones de alfabetización en la educación a todas las edades—preescolar hasta adulto—en los últimos diez años. Al examinar más de 300 estudios, vimos que un tema común es el de entender cómo lograr exitosamente la educación de competencias de todos los estudiantes. Organizamos el repaso en dos secciones complementarias. Enfocamos la primera en los acercamientos analíticos del discurso que se han usado para investigar: ¿Cuáles competencias cuentan o valen? ¿Las competencias de quiénes cuentan o valen? La segunda sección explica las contribuciones que hicieron los estudios organizadas de acuerdo a cinco temas: ¿Qué son identidades competentes, cómo se construyen, y por quiénes? ¿Cómo se construyen el conocimiento, el discurso y las identidades de las disciplinas? ¿Cómo pueden las escuelas darles acceso a los estudiantes a las competencias basadas en la escuela? ¿Cuáles son los papeles cambiantes de los maestros y los estudiantes de competencias dentro y fuera de la escuela? ¿Cómo plantea la investigación del análisis del discurso el movimiento dentro y a través de los sitios de competencias y prácticas en este mundo contemporáneo, globalizado y digital?Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88086/1/RRQ.45.1.5.pd

Ethnicity and consumption: South Asian food shopping patterns in Britain 1947-75

Authors' draft version also available on University of Surrey e-print repository. Final version published by Sage and available at http://joc.sagepub.com/This article reviews the literature that explores the relationship between ethnic identities and food consumption, with particular reference to business management studies. It focuses on the food shopping practices of south Asians in Britain in the period 1947 to 1975, to illustrate the need for more historically contextualized studies that can provide a more nuanced exploration of any interconnections between ethnic identity and shopping behaviour. The article draws on a reasonably long-standing interest in ethnicity and consumption in marketing studies, and explores the conceptual use of acculturation within this literature. The arguments put forward are framed by recent interdisciplinary studies of the broader relationship between consumption and identity, which stress the importance of contextualizing any influence of ethnic identifications through a wider consideration of other factors including societal status, gender and age, rather than giving it singular treatment. The article uses a body of empirical research drawn from recent oral histories, to explore how these factors informed everyday shopping practices among south Asians in Britain. It examines some of the shopping and wider food provisioning strategies adopted by early immigrants on arrival in Britain. It considers the interaction between the south Asian population and the changing retail structure, in the context of the development of self-service and the supermarket. Finally, it demonstrates how age, gender and socioeconomic status interacted with ethnic identities to produce variations in shopping patterns

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

Human Embryonic Stem Cells Express Elevated Levels of Multiple Pro-Apoptotic BCL-2 Family Members

Two of the greatest challenges in regenerative medicine today remain (1) the ability to culture human embryonic stem cells (hESCs) at a scale sufficient to satisfy clinical demand and (2) the ability to eliminate teratoma-forming cells from preparations of cells with clinically desirable phenotypes. Understanding the pathways governing apoptosis in hESCs may provide a means to address these issues. Limiting apoptosis could aid scaling efforts, whereas triggering selective apoptosis in hESCs could eliminate unwanted teratoma-forming cells. We focus here on the BCL-2 family of proteins, which regulate mitochondrial-dependent apoptosis. We used quantitative PCR to compare the steady-state expression profile of all human BCL-2 family members in hESCs with that of human primary cells from various origins and two cancer lines. Our findings indicate that hESCs express elevated levels of the pro-apoptotic BH3-only BCL-2 family members NOXA, BIK, BIM, BMF and PUMA when compared with differentiated cells and cancer cells. However, compensatory expression of pro-survival BCL-2 family members in hESCs was not observed, suggesting a possible explanation for the elevated rates of apoptosis observed in proliferating hESC cultures, as well as a mechanism that could be exploited to limit hESC-derived neoplasms

Semi-Automated Image Analysis for the Assessment of Megafaunal Densities at the Arctic Deep-Sea Observatory HAUSGARTEN

Megafauna play an important role in benthic ecosystem function and are sensitive indicators of environmental change. Non-invasive monitoring of benthic communities can be accomplished by seafloor imaging. However, manual quantification of megafauna in images is labor-intensive and therefore, this organism size class is often neglected in ecosystem studies. Automated image analysis has been proposed as a possible approach to such analysis, but the heterogeneity of megafaunal communities poses a non-trivial challenge for such automated techniques. Here, the potential of a generalized object detection architecture, referred to as iSIS (intelligent Screening of underwater Image Sequences), for the quantification of a heterogenous group of megafauna taxa is investigated. The iSIS system is tuned for a particular image sequence (i.e. a transect) using a small subset of the images, in which megafauna taxa positions were previously marked by an expert. To investigate the potential of iSIS and compare its results with those obtained from human experts, a group of eight different taxa from one camera transect of seafloor images taken at the Arctic deep-sea observatory HAUSGARTEN is used. The results show that inter- and intra-observer agreements of human experts exhibit considerable variation between the species, with a similar degree of variation apparent in the automatically derived results obtained by iSIS. Whilst some taxa (e. g. Bathycrinus stalks, Kolga hyalina, small white sea anemone) were well detected by iSIS (i. e. overall Sensitivity: 87%, overall Positive Predictive Value: 67%), some taxa such as the small sea cucumber Elpidia heckeri remain challenging, for both human observers and iSIS

Semi-Automated Image Analysis for the Assessment of Megafaunal Densities at the Arctic Deep-Sea Observatory HAUSGARTEN

Megafauna play an important role in benthic ecosystem function and are sensitive indicators of environmental change. Non-invasive monitoring of benthic communities can be accomplished by seafloor imaging. However, manual quantification of megafauna in images is labor-intensive and therefore, this organism size class is often neglected in ecosystem studies. Automated image analysis has been proposed as a possible approach to such analysis, but the heterogeneity of megafaunal communities poses a non-trivial challenge for such automated techniques. Here, the potential of a generalized object detection architecture, referred to as iSIS (intelligent Screening of underwater Image Sequences), for the quantification of a heterogenous group of megafauna taxa is investigated. The iSIS system is tuned for a particular image sequence (i.e. a transect) using a small subset of the images, in which megafauna taxa positions were previously marked by an expert. To investigate the potential of iSIS and compare its results with those obtained from human experts, a group of eight different taxa from one camera transect of seafloor images taken at the Arctic deep-sea observatory HAUSGARTEN is used. The results show that inter- and intra-observer agreements of human experts exhibit considerable variation between the species, with a similar degree of variation apparent in the automatically derived results obtained by iSIS. Whilst some taxa (e. g. Bathycrinus stalks, Kolga hyalina, small white sea anemone) were well detected by iSIS (i. e. overall Sensitivity: 87%, overall Positive Predictive Value: 67%), some taxa such as the small sea cucumber Elpidia heckeri remain challenging, for both human observers and iSIS