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En este artículo examino la psicología como una forma de práctica educacional a través de explorar la experiencia de los estudiantes, los mundos de la investigación y enseñanza psicológica, el surgimiento de movimientos críticos alternativos y el papel que juega la psicología en las prácticas coercitivas de gestión. Se trata de una oportunidad de reflexión crítica sobre el verdadero modus operandi de la psicología en sucarácter de disciplina académica, qué enseña en la instrucción superior y cómo lucen las comunidades de investigación alrededor del globo, y qué crisis institucionales provoca esta ciencia.

The membrane protein TREM2 (Triggering Receptor Expressed on Myeloid cells 2) regulates key microglial functions including phagocytosis and chemotaxis. Loss-of-function variants of TREM2 are associated with increased risk of Alzheimer’s disease (AD). Because abnormalities in Ca2+ signaling have been observed in several AD models, we investigated TREM2 regulation of Ca2+ signaling in human induced pluripotent stem cell-derived microglia (iPSC-microglia) with genetic deletion of TREM2. We found that iPSC-microglia lacking TREM2 (TREM2 KO) show exaggerated Ca2+ signals in response to purinergic agonists, such as ADP, that shape microglial injury responses. This ADP hypersensitivity, driven by increased expression of P2Y12 and P2Y13 receptors, results in greater release of Ca2+ from the endoplasmic reticulum stores, which triggers sustained Ca2+ influx through Orai channels and alters cell motility in TREM2 KO microglia. Using iPSC-microglia expressing the genetically encoded Ca2+ probe, Salsa6f, we found that cytosolic Ca2+ tunes motility to a greater extent in TREM2 KO microglia. Despite showing greater overall displacement, TREM2 KO microglia exhibit reduced directional chemotaxis along ADP gradients. Accordingly, the chemotactic defect in TREM2 KO microglia was rescued by reducing cytosolic Ca2+ using a P2Y12 receptor antagonist. Our results show that loss of TREM2 confers a defect in microglial Ca2+ response to purinergic signals, suggesting a window of Ca2+ signaling for optimal microglial motility.

Este manifiesto es para movimientos de liberación por un mundo mejor. Trata sobre la interrelación entre la realidad opresiva de la vida actual y nuestras vidas ‘internas’, nuestra psicología. El psicoanálisis capta esa íntima interconexión entre esta realidad y lo que se siente en lo profundo de cada uno/a de nosotros/as. Debemos comprender la naturaleza de esa interconexión para construir una alternativa práctica al capitalismo, el sexismo y el racismo. Nuestra tarea es reconstruir el psicoanálisis como una forma auténtica de ‘psicología crítica’. Analizamos el papel del inconsciente, la repetición, la pulsión y la transferencia en el análisis clínico y político para abordar cuestiones de transformación subjetiva.

Strong evidence indicates that amyloid beta (Aβ) inflicts its toxicity in Alzheimer’s disease (AD) by promoting uncontrolled elevation of cytosolic Ca2+ in neurons. We have previously shown that synthetic Aβ42 oligomers stimulate abnormal intracellular Ca2+ release from the endoplasmic reticulum stores, suggesting that a similar mechanism of Ca2+ toxicity may be common to the endogenous Aβs oligomers. Here, we use human postmortem brain extracts from AD-affected patients and test their ability to trigger Ca2+ fluxes when injected intracellularly into Xenopus oocytes. Immunological characterization of the samples revealed the elevated content of soluble Aβ oligomers only in samples from AD patients. Intracellular injection of brain extracts from control patients failed to trigger detectable changes in intracellular Ca2+. Conversely, brain extracts from AD patients triggered Ca2+ events consisting of local and global Ca2+ fluorescent transients. Pre-incubation with either the conformation-specific OC antiserum or caffeine completely suppressed the brain extract’s ability to trigger cytosolic Ca2+ events. Computational modeling suggests that these Ca2+ fluxes may impair cells bioenergetic by affecting ATP and ROS production. These results support the hypothesis that Aβ oligomers contained in neurons of AD-affected brains may represent the toxic agents responsible for neuronal malfunctioning and death associated with the disruption of Ca2+ homeostasis.

Este artigo argumenta que Freud não aceitou a esfera da “psicologia” como algo dado, que poderia ser conhecido objetivamente. Tampouco ele a via como algo unitário que seria sempre o mesmo e em qualquer pessoa. Ao invés disso, ofereceu ideias valiosas sobre a natureza humana da miséria enquanto algo histórico, sobre o processo dialético através do qual podemos entender a miséria como algo condensado em sintomas, e sobre a relação entre compreensão e libertação. Nós argumentamos que a psicanálise precisa ser recriada por nós enquanto uma ferramenta de trabalho radical sobre a subjetividade para derrubar as condições existentes. Argumentamos em favor de uma compreensão dialética da psicanálise como uma ferramenta e um resultado; essa ferramenta é o resultado das elaborações teóricas de Freud e seus seguidores, que nos permitiram usá-la para um trabalho radical na clínica e em movimentos de libertação. Ela torna possível uma “subjetividade revolucionária”, um “sujeito revolucionário”.

Modulating cytoplasmic Ca2+ concentration ([Ca2+]i) by endoplasmic reticulum (ER)-localized inositol 1,4,5-trisphosphate receptor (InsP3R) Ca2+-release channels is a universal signaling pathway that regulates numerous cell-physiological processes. Whereas much is known regarding regulation of InsP3R activity by cytoplasmic ligands and processes, its regulation by ER-luminal Ca2+ concentration ([Ca2+]ER) is poorly understood and controversial. We discovered that the InsP3R is regulated by a peripheral membrane-associated ER-luminal protein that strongly inhibits the channel in the presence of high, physiological [Ca2+]ER. The widely-expressed Ca2+-binding protein annexin A1 (ANXA1) is present in the nuclear envelope lumen and, through interaction with a luminal region of the channel, can modify high-[Ca2+]ER inhibition of InsP3R activity. Genetic knockdown of ANXA1 expression enhanced global and local elementary InsP3-mediated Ca2+ signaling events. Thus, [Ca2+]ER is a major regulator of InsP3R channel activity and InsP3R-mediated [Ca2+]i signaling in cells by controlling an interaction of the channel with a peripheral membrane-associated Ca2+-binding protein, likely ANXA1.

The ‘building-block’ model of inositol trisphosphate (IP3)-mediated Ca2+ liberation posits that cell-wide cytosolic Ca2+ signals arise through coordinated activation of localized Ca2+ puffs generated by stationary clusters of IP3 receptors (IP3Rs). Here, we revise this hypothesis, applying fluctuation analysis to resolve Ca2+ signals otherwise obscured during large Ca2+ elevations. We find the rising phase of global Ca2+ signals is punctuated by a flurry of puffs, which terminate before the peak by a mechanism involving partial ER Ca2+ depletion. The continuing rise in Ca2+, and persistence of global signals even when puffs are absent, reveal a second mode of spatiotemporally diffuse Ca2+ signaling. Puffs make only small, transient contributions to global Ca2+ signals, which are sustained by diffuse release of Ca2+ through a functionally distinct process. These two modes of IP3-mediated Ca2+ liberation have important implications for downstream signaling, imparting spatial and kinetic specificity to Ca2+-dependent effector functions and Ca2+ transport.

This paper briefly describes the formation, present-day functioning and problems facing the futuristic city ‘Auroville’ in the state of Tamil Nadu in south India. Founded in 1968 as a ‘universal’ city, and planned to have 50,000 inhabitants that would take the next step in human evolution to exist as a self-sustaining community independent of nation states, Auroville manifests another utopian attempt to create a ‘common’ space which resonates with communist hopes to reclaim the commons from capitalist enclosure. This paper explores the problems that face Auroville when it creates its ‘commons’ on existing peasant land and becomes implicated in colonial politics.

The archetypal sage character is a common, though relatively unexplored character, in young adult literature (YAL). Employing a sociocultural, constructivist understanding of archetypes, we unpack features of the sage through an examination of three sagacious characters: the Receiver of Memory in The Giver, Haymitch Abernathy in The Hunger Games, and Anatov in Akata Witch. Our analysis reveals how these characters are each marked with physical or behavioral abnormalities, are isolated from society and its institutions, and possess dangerous knowledge of eros (The Giver), power (The Hunger Games), and identity (Akata Witch). They are also depicted as standing in sharp contrast to other, more typical teachers in the intimate relationships they form with students and degree of vulnerability they display. All of these characteristics, we argue, might explain the appeal of the sagecharacter in YAL, as well as its curious absence from our common understanding of K-12 teachers and curriculum. Indeed, we see these characterizations of fictional teachers as raising interesting questions about sagacious mentorship and wisdom in schools.

Ca2+ influx through Orai1 channels is crucial for several T cell functions, but a role in regulating basal cellular motility has not been described. Here, we show that inhibition of Orai1 channel activity increases average cell velocities by reducing the frequency of pauses in human T cells migrating through confined spaces, even in the absence of extrinsic cell contacts or antigen recognition. Utilizing a novel ratiometric genetically encoded cytosolic Ca2+ indicator, Salsa6f, which permits real-time monitoring of cytosolic Ca2+ along with cell motility, we show that spontaneous pauses during T cell motility in vitro and in vivo coincide with episodes of cytosolic Ca2+ signaling. Furthermore, lymph node T cells exhibited two types of spontaneous Ca2+ transients: short-duration ‘sparkles’ and longer duration global signals. Our results demonstrate that spontaneous and self-peptide MHC-dependent activation of Orai1 ensures random walk behavior in T cells to optimize immune surveillance.

Calcium is an essential cellular messenger that regulates numerous functions in living organisms. Here, we describe development and characterization of ‘Salsa6f’, a fusion of GCaMP6f and tdTomato optimized for cell tracking while monitoring cytosolic Ca2+, and a transgenic Ca2+ reporter mouse with Salsa6f targeted to the Rosa26 locus for Cre-dependent expression in specific cell types. The development and function of T cells was unaffected in Cd4-Salsa6f mice. We describe Ca2+ signals reported by Salsa6f during T cell receptor activation in naive T cells, helper Th17 T cells and regulatory T cells, and Ca2+ signals mediated in T cells by an activator of mechanosensitive Piezo1 channels. Transgenic expression of Salsa6f enables ratiometric imaging of Ca2+ signals in complex tissue environments found in vivo. Two-photon imaging of migrating T cells in the steady-state lymph node revealed both cell-wide and localized sub-cellular Ca2+ transients (‘sparkles’) as cells migrate.

En este artículo se analiza a Podemos desde la noción de “acontecimiento” teorizada por Alain Badiou y sobre la base de dos cuestiones que se relacionan con Podemos como fenómeno anti-político. En primer lugar, en lo relativo a la relación entre discurso académico y acontecimientos políticos, llegando a la conclusión de que tanto Badiou como el grupo de la Complutense que rodea a Iglesias intervinieron con éxito sobre el mundo real, desde la Universidad, desde un marco académico. La segunda cuestión tiene que ver con el modo en que nos relacionamos con acontecimientos que aun no han ocurrido. Parker concluye que el futuro de Podemos está íntimamente ligado a lo que pueda ocurrir en Grecia tras la victoria de Syriza. En este artículo se describe el impacto positivo que ha tenido Podemos para el “Left Unity” en Manchester y se aboga por un compromiso con ambas formaciones más allá de lo puramente académico. Podemos y Syriza son posibles acontecimientos cuyo carácter está aún por determinar, y cuyas implicaciones traspasan incluso las fronteras de Europa.

The oscillating concentration of intracellular calcium is one of the most important examples for collective dynamics in cell biology. Localized releases of calcium through clusters of inositol 1,4,5-trisphosphate receptor channels constitute elementary signals called calcium puffs. Coupling by diffusing calcium leads to global releases and waves, but the exact mechanism of inter-cluster coupling and triggering of waves is unknown. To elucidate the relation of puffs and waves, we here model a cluster of IP3R channels using a gating scheme with variable non-equilibrium IP3 binding. Hybrid stochastic and deterministic simulations show that puffs are not stereotyped events of constant duration but are sensitive to stimulation strength and residual calcium. For increasing IP3 concentration, the release events become modulated at a timescale of minutes, with repetitive wave-like releases interspersed with several puffs. This modulation is consistent with experimental observations we present, including refractoriness and increase of puff frequency during the inter-wave interval. Our results suggest that waves are established by a random but time-modulated appearance of sustained release events, which have a high potential to trigger and synchronize activity throughout the cell.

Amyloid beta (Aβ) oligomers associated with Alzheimer's disease (AD) form Ca2+-permeable plasma membrane pores, leading to a disruption of the otherwise well-controlled intracellular calcium (Ca2+) homeostasis. The resultant up-regulation of intracellular Ca2+ concentration has detrimental implications for memory formation and cell survival. The gating kinetics and Ca2+ permeability of Aβ pores are not well understood. We have used computational modeling in conjunction with the ability of optical patch-clamping for massively parallel imaging of Ca2+ flux through thousands of pores in the cell membrane of Xenopus oocytes to elucidate the kinetic properties of Aβ pores. The fluorescence time-series data from individual pores were idealized and used to develop data-driven Markov chain models for the kinetics of the Aβ pore at different stages of its evolution. Our study provides the first demonstration of developing Markov chain models for ion channel gating that are driven by optical-patch clamp data with the advantage of experiments being performed under close to physiological conditions. Towards the end, we demonstrate the up-regulation of gating of various Ca2+ release channels due to Aβ pores and show that the extent and spatial range of such up-regulation increases as Aβ pores with low open probability and Ca2+ permeability transition into those with high open probability and Ca2+ permeability.

Total internal reflection fluorescence (TIRF) microscopy is a powerful tool for visualizing near-membrane cellular structures and processes, including imaging of local Ca2+ transients with single-channel resolution. TIRF is most commonly implemented in epi-fluorescence mode, whereby laser excitation light is introduced at a spot near the periphery of the back focal plane of a high numerical aperture objective lens. However, this approach results in an irregular illumination field, owing to interference fringes and scattering and shadowing by cellular structures. We describe a simple system to circumvent these limitations, utilizing a pair of galvanometer-driven mirrors to rapidly spin the laser spot in a circle at the back focal plane of the objective lens, so that irregularities average out during each camera exposure to produce an effectively uniform field. Computer control of the mirrors enables precise scanning at 200 Hz (5ms camera exposure times) or faster, and the scan radius can be altered on a frame-by-frame basis to achieve near-simultaneous imaging in TIRF, widefield and 'skimming plane' imaging modes. We demonstrate the utility of the system for dynamic recording of local inositol trisphosphate-mediated Ca2+ signals and for imaging the redistribution of STIM and Orai proteins during store-operated Ca2+ entry. We further anticipate that it will be readily applicable for numerous other near-membrane studies, especially those involving fast dynamic processes.

Algunas de las especulaciones acerca de la relación entre tecnología y la naturaleza humana que se encuentran en los escritos de Ciencia Ficción del último medio siglo han pasado a formar parte del lenguaje y la cotidianidad de los sujetos post-industriales. Los futuros que se dibujan en los textos de Ciencia Ficción ayudan a entender en qué nos hemos convertido. Las nuevas formas de experiencia, las relaciones sociales y las formas de subjetividad que se hallan en la Ciencia Ficción pueden considerarse como recursos legítimos para el examen del presente. Y, en la medida que el pasado se reproduce a partir de nuevos sistemas dominantes de significados, lo que entendemos como realidad a partir de la tecnología y la naturaleza empieza a desaparecer. A menudo se llega a esta situación cuando no se sabe qué realidad es la correcta entre la miríada de realidades alternativas. Este artículo explora el modo en que el discurso psicoanalítico, tan enraizado en la cultura popular, encuentra en la psicología uno de sus máximos exponentes para fomentar subjetividades en armonía con la sociedad contemporánea.

The microdomains of Ca2+ in the cytosol around the mouth of open Ca2+ channels are the basic `building blocks' from which cellular Ca2+ signals are constructed. Moreover, the kinetics of local [Ca2+] closely reflect channel gating, so their measurement holds promise as an alternative to electrophysiological patch-clamp recording as a means to study single channel behavior. We have thus explored the development of optical techniques capable of imaging single-channel Ca2+ signals with good spatial and temporal resolution, and describe results obtained using total internal reflection fluorescence microscopy to monitor Ca2+ influx through single N-type channels expressed in Xenopus oocytes

O encontro intelectual entre três escritores simpáticos, em algum nível, ao trabalho de Lacan foi reunido no livro Contingência, Hegemonia, Universalidade (Butler, Laclau e Zizek, 2000a). Esses três autores são bem conhecidos em um conjunto difuso de campos que vão dos "estudos culturais" (cultural studies) à teoria literária e à teoria política. Como o subtítulo do livro indica - "Diálogos Contemporâneos da Esquerda" - eles também possuem alguma afinidade com o marxismo, "pós-marxismo" e política feminista. Uma questão que este debate entre três pensadores da teoria social lacaniana freqüentemente recoloca diz respeito à possibilidade de articular a teoria lacaniana com a política radical. No presente artigo discute-se se há implicações clínicas para esta leitura proposta pela esquerda Lacaniana, na qual os três autores estão engajados. Tomando como ponto de confluência o livro acima, o objetivo trabalho é mostrar como a prática política e a prática clínica encontram certos pontos de congruência em torno de temas como a negatividade, a sexualidade e a subversão do sujeito.An intellectual encounter between three writers sympathetic to some degree with Lacan's work has been recorded in the book Contingency, Hegemony, Universality (Butler, Laclau and ·i·ek, 2000a). These three writers are well known in the overlapping collection of fuzzy sets "cultural studies", "literary theory" and "political theory", and, as the subtitle of the book "Contemporary Dialogues on the Left" indicates, they also have some sympathy with Marxist, "post-marxist" or feminist politics. One question that the debate between the three often returns to is whether it is possible to articulate Lacanian theory with radical politics. However, another question that is embedded in the encounter but which is only obliquely addressed is whether there are clinical implications for the kind of leftist readings of Lacan that these three writers engage in. I focus on that question in this paper.

Manchester’s ‘northern quarter’, an area targeted for regeneration – cheap hostels, clubs, old textile businesses and new cafe bars – was, on the Tuesday evening, rapidly shutting up shop. There had been rumours from late afternoon that Salford about a mile away had seen trouble, and restaurant owners round here were taking no chances. We took refuge in a Lebanese place off Oldham Street while the kids set off on their bikes to see what was happening a block or two south and reported back from time to time on events in Piccadilly gardens. An occasional flash of blue light, people sprinting from one alleyway to the other, stories of stones thrown, and all this in a growing atmosphere of tense, expectant, unusual silence. The trams and bus system closed down by mid-evening, music venues were told by the authorities to stop early, so by now there was a different mix; city centre workers and customers were moving out, anxious about how to get home, some locals were working their way down to the centre to see what was what, and small huddles of youth hung around the corners with nowhere to go. Everyone looked suspicious, looking suspiciously at each other, made objects of suspicion, and already separation was at work, division of each from the other, and no place in this for solidarity, just disorganisation and uncertainty about what would happen next.

El “barrio norte” de Manchester, una zona objetivo de rehabilitación –hoteles baratos, clubs, viejos negocios textiles y modernos cafés– se convirtió aquel martes por la tarde en una tienda que cerraba sus puertas apresuradamente. A última hora de la tarde circulaban rumores de que en Salford, a escasa distancia de allí, se había armado. Los dueños de los restaurantes no estaban para correr ningún riesgo. Nos refugiamos en un libanés de una bocacalle de Oldham Street mientras los niños marchaban en bici a echar un vistazo un par de edificios hacia el sur; venían de tanto en cuando a dar el parte sobre los acontecimientos, del parque de Piccadilly. Podíamos ver algún que otro destello azul, personas que pasaban corriendo de un callejón a otro, relatos de piedras lanzadas; todo transcurría en medio de un silencio cada vez más tenso, expectante, inusual. Los tranvías y autobuses habían dejado de funcionar a media tarde, las autoridades pidieron que los locales de conciertos cerraran pronto, de modo que a esas horas el ambiente era distinto a otros días. Los trabajadores y clientes del centro de la ciudad empezaban a marcharse, inquietos por cómo volver a sus casas, algunos bajaban al centro para ver qué pasaba, y pequeños grupos de jóvenes permanecían en las esquinas sin lugar al que ir. Todos parecían sospechosos, todos se miraban, todos se habían convertido en objeto de sospecha; se iniciaba el proceso de separación, de división entre unos y otros, que no dejaba espacio a la solidaridad; un escenario de desorganización e incertidumbre sobre lo estaba por venirManchester’s ‘northern quarter’, an area targeted for regeneration – cheap hostels, clubs, old textile businesses and new cafe bars – was, on the Tuesday evening, rapidly shutting up shop. There had been rumours from late afternoon that Salford about a mile away had seen trouble, and restaurant owners round here were taking no chances. We took refuge in a Lebanese place off Oldham Street while the kids set off on their bikes to see what was happening a block or two south and reported back from time to time on events in Piccadilly gardens. An occasional flash of blue light, people sprinting from one alleyway to the other, stories of stones thrown, and all this in a growing atmosphere of tense, expectant, unusual silence. The trams and bus system closed down by mid-evening, music venues were told by the authorities to stop early, so by now there was a different mix; city centre workers and customers were moving out, anxious about how to get home, some locals were working their way down to the centre to see what was what, and small huddles of youth hung around the corners with nowhere to go. Everyone looked suspicious, looking suspiciously at each other, made objects of suspicion, and already separation was at work, division of each from the other, and no place in this for solidarity, just disorganisation and uncertainty about what would happen next.

Mutations in presenilin-1 (PS1), the leading cause of early-onset, autosomal-dominant familial Alzheimer's disease (FAD), enhance calcium signaling mediated by inositol 1,4,5-trisphosphate (IP3). To elucidate the subcellular mechanisms underlying this enhancement, we used high resolution line-scanning confocal microscopy to image elementary calcium release events (“puffs”) in Xenopus oocytes expressing wild-type or mutant PS1. Here we report that mutant PS1-rendered puffs more sensitive to IP3 and increased both the magnitude and the rate of calcium release during each event. These effects were not attributable to quantitative changes in the levels of IP3 receptors or their distribution on the ER, but were instead associated with an abnormal elevation of ER calcium stores. Together, our results suggest that the effects of mutant PS1 on calcium signaling are manifested predominantly at the level of the regulation of calcium stores rather than via perturbations in the numbers or activity of IP3-activated calcium release channels.

Influenza-induced lung edema and inflammation are exacerbated by a positive feedback loop of cytokine and chemokine production termed a 'cytokine storm', a hallmark of increased influenza-related morbidity and mortality. Upon infection, an immune response is rapidly initiated in the lungs and draining lymph node, leading to expansion of virus-specific effector cells. Using two-photon microscopy, we imaged the dynamics of dendritic cells (DC) and virus-specific eGFP(+)CD8(+) T cells in the lungs and draining mediastinal lymph nodes during the first two weeks following influenza infection. Three distinct phases of T cell and CD11c(+) DC behavior were revealed: 1) Priming, facilitated by the arrival of lung DCs in the lymph node and characterized by antigen recognition and expansion of antigen-specific CD8(+) T cells; asymmetric T cell division in contact with DCs was frequently observed. 2) Clearance, during which DCs re-populate the lung and T cells leave the draining lymph node and re-enter the lung tissue where enlarged, motile T cells come into contact with DCs and form long-lived interactions. 3) Maintenance, characterized by T-cell scanning of the lung tissue and dissociation from local antigen presenting cells; the T cells spend less time in association with DCs and migrate rapidly on collagen. A single dose of a sphingosine-1-phosphate receptor agonist, AAL-R, sufficient to suppress influenza-induced cytokine-storm, altered T cell and DC behavior during influenza clearance, delaying T cell division, cellular infiltration in the lung, and suppressing T-DC interactions in the lung. Our results provide a detailed description of T cell and DC choreography and dynamics in the lymph node and the lung during influenza infection. In addition, we suggest that phase lags in T cell and DC dynamics induced by targeting S1P receptors in vivo may attenuate the intensity of the immune response and can be manipulated for therapeutic benefit.

Dendritic cells (DCs) play a key role in initiating adaptive immune response by presenting antigen to T cells in lymphoid organs. Here, we investigate the potential of quantum dots (QDs) as fluorescent nanoparticles for in vitro and in vivo imaging of DCs, and as a particle-based antigen-delivery system to enhance DC-mediated immune responses. We used confocal, two-photon, and electron microscopies to visualize QD uptake into DCs and compared CD69 expression, T cell proliferation, and IFN-gamma production by DO11.10 and OT-II T cells in vivo in response to free antigen or antigen-conjugated to QDs. CD11c(+) DCs avidly and preferentially endocytosed QDs, initially into small vesicles near the plasma membrane by an actin-dependent mechanism. Within 10 min DCs contained vesicles of varying size, motion, and brightness distributed throughout the cytoplasm. At later times, endocytosed QDs were compartmentalized inside lysosomes. LPS-induced maturation of DCs reduced the rate of endocytosis and the proportion of cells taking up QDs. Following subcutaneous injection of QDs in an adjuvant depot, DCs that had endocytosed QDs were visualized up to 400 microm deep within draining lymph nodes. When antigen-conjugated QDs were used, T cells formed stable clusters in contact with DCs. Antigen-conjugated QDs induced CD69 expression, T cell proliferation, and IFN-gamma production in vivo with greater efficiency than equivalent amounts of free antigen. These results establish QDs as a versatile platform for immunoimaging of dendritic cells and as an efficient nanoparticle-based antigen delivery system for priming an immune response.

Interactions between B and T cells are essential for most antibody responses, but the dynamics of these interactions are poorly understood. By two-photon microscopy of intact lymph nodes, we show that upon exposure to antigen, B cells migrate with directional preference toward the B-zone-T-zone boundary in a CCR7-dependent manner, through a region that exhibits a CCR7-ligand gradient. Initially the B cells show reduced motility, but after 1 d, motility is increased to approximately 9 microm/min. Antigen-engaged B cells pair with antigen-specific helper T cells for 10 to more than 60 min, whereas non-antigen-specific interactions last less than 10 min. B cell-T cell conjugates are highly dynamic and migrate extensively, being led by B cells. B cells occasionally contact more than one T cell, whereas T cells are strictly monogamous in their interactions. These findings provide evidence of lymphocyte chemotaxis in vivo, and they begin to define the spatiotemporal cellular dynamics associated with T cell-dependent antibody responses.

In this paper, we revisit a long-running conversation about situated learning and the design of environments for disciplinary engagement. Throughout the 1970s and 1980s, scholars advanced an anthropological critique of the then-dominant acquisitionist paradigm of formal schooling with a situated view focused on membership in communities and participation in practices. The critique led to a practice turn in education and a consensus model for reform-oriented school classrooms as orchestrated practice fields where students engage in disciplinary practices within a structured environment. Questions remain, however, about the nature of the practices and communities that this model engenders. We join this conversation through an anthropological investigation of a self-organized group of teachers who gather outside of school hours to engage in collaborative mathematical activity. Participants have the flexibility to conduct their mathematical activity however they want; yet as we show, they tend to reproduce a practice field resembling a reform-oriented school mathematics classroom. This may seem unremarkable, even desirable for many reformers. However, assuming that teachers can or should only replicate practice fields when doing mathematics may be selling them short. Our findings suggest a durability and invisibility to practice fields that may be limiting the possibilities for the production of novel learning communities within schools.

Educators need collaborative opportunities to renew their love of learning, not just to review data and rework lessons. Researcher Ian Parker Renga and coauthors examine the power of Math Teachers' Circles--a group of educators that get together to play math games and solve problems just for the joy of it.

Many classroom units and lessons are now organized around engaging students in developing claims and evidence. An aspect of teachers' work that is understudied is how teachers manage the complexity inherent in navigating between claims and empirical data. In other words, what do teachers do when students do not see what they are "supposed to" see or when they make sense of observations in unexpected ways? We contend that such complexity is inherent to the scientific endeavor, and that engaging with it is central to doing science. Therefore, the moves that science teachers make in this context have important consequences for students' conceptual and epistemic understandings. We apply an "epistemic levels" coding scheme to three classroom episodes in order to better understand the complexity of classroom evidence construction and to develop a description of strategies that teachers might enact to manage this complexity. We then discuss the implications of these strategies for how students are positioned to engage in scientific knowledge construction.

Much of the public discourse on education arguably reinforces the assumption that most stakeholders share the same desires for teaching and learning--desires reflecting a liberal paradigm that stresses individualism, control, and efficiency. But there are other desires, and additional empirical research informed by a Vygotskian sociocultural theory of learning could enrich this discourse. In my view, such research could benefit from a framework of desire compatible with the theory's central assumptions of learning as socially situated in cultural practices, teleological, and transformational. To this purpose, I offer a liturgical framing of desire put forth by James K. A. Smith, which treats humans as essentially desiring beings and defines desire as a potent force formed through participation in communal practices that orient practitioners' hearts ("eros") toward particular futures ("telos"). I show how this framing satisfies key features of sociocultural theory and highlight two examples of how desire has been qualitatively examined and where the framing might enrich further examinations of education settings.

Formative assessment has been recognized as an essential element of effective classroom practice; as a result, teachers are increasingly required to create formative assessments for their classrooms. This study examines data drawn from a long-term, site-based professional development program that supported a department of biology teachers in the iterative design and enactment of common formative assessment tools. We analyze teacher conversations to understand how teachers collaborated to design formative assessments. Results indicate that when teachers attended to problems of practice related to teaching evolution, increased transparency in their talk helped build consensus about the design of formative assessment tools. These results highlight the importance of encouraging transparency in teacher dialog when they are engaged in collaborative design of formative assessments.