Homochiral oligopeptides by chiral amplification: Interpretation of experimental data with a copolymerization model

We present a differential rate equation model of chiral polymerization based on a simple copolymerization scheme in which the enantiomers are added to, or removed from, the homochiral or heterochiral chains (reversible stepwise isodesmic growth or dissociation). The model is set up for closed systems and takes into account the corresponding thermodynamic constraints implied by the reversible monomer attachments, while obeying a constant mass constraint. In its simplest form, the model depends on a single variable rate constant, the maximum chain length N, and the initial concentrations. We have fit the model to the experimental data from the Rehovot group on lattice-controlled chiral amplification of oligopeptides. We find in all the chemical systems employed except for one, that the model fits the measured relative abundances of the oligopetides with higher degrees of correlation than from a purely random polymerization process.Comment: 18 pages, 12 figures, 9 table

Reorienting American Liberal Judaism for the Twentieth Century: Stephen S. Wise and the Early Years of the Jewish Institute of Religion

This study explores how Rabbi Stephen S. Wise and supporters from the Free Synagogue and elsewhere sought to reorient American liberal Judaism by establishing the Jewish Institute of Religion (JIR) in the early 1920s. They believed the leaders of the Reform movement at that time were reluctant to relinquish an outmoded approach that had lost relevance in light of a new demographic reality whereby over a million Eastern European Jews now living in New York were becoming the dominant presence in American Jewish life. The JIR founders attributed this to Reform\u27s having become insular, unresponsive to pressing social issues, overly concerned with respectability, and spiritually lifeless. Wise and his circle advanced a vision for liberal Judaism they considered to be more modern and American, more liberal and more deeply Jewish. While they attempted to advance their vision for liberal Judaism on many fronts, they believed that critical to the task was creating a New York-based scholarly center capable of training a new kind of rabbi. This work describes the key individuals in addition to Wise who created the Institute, the international scholars who formed the first faculty, and the debates that ensued and obstacles encountered as the institution took shape. From the outset, the founders determined that JIR would differ from existing schools in significant ways. For example, prioritizing the oneness of Israel, JIR would include faculty and students representing a broad spectrum of belief, from Orthodox to non-Orthodox, and Zionist to non-Zionist. All students would enter with a bachelor\u27s degree, and in addition to studying traditional fields like Bible, history and Talmud, they would study modern Hebrew, social service and contemporary trends in Jewish education. In addition, through fieldwork, students would utilize the metropolitan area as a laboratory for learning how to serve American Jewry as inspiring, socially-engaged rabbis. With these and other innovations, Wise and the founders believed JIR would point twentieth-century liberal Judaism in new directions. Though they did not succeed in all they set out to achieve, many aspects of the reorientation of American Jewish religious life they pursued remain with us today

Cosmopolitan Continuities: The Re-Framing of Historic Architecture and Urban Space in Contemporary Morocco (1990-Present)

What is the political and economic significance of old buildings, neighborhoods, and monuments in contemporary Moroccan cities? I address this question by studying historic preservation efforts of state and non-state actors in two Moroccan cities: Tetouan and Rabat. In this study, I argue that two separate elite coalitions of state officials, architects, artists, academics, and activists in the Moroccan cities of Tetouan and Rabat frame their historic architecture and urban spaces (from before Moroccan independence) as demonstrating the city and nation’s enduring cosmopolitanism. By framing their urban heritage, and subsequently their history as cosmopolitan, this elite coalition asserts that Morocco has always been multicultural, tolerant, and open to new ideas. This allows Moroccans to more effectively insert themselves into contemporary global capital and cultural flows while simultaneously promoting a sense of national and local identity. This identity is grounded in the idea of “Moroccan exceptionalism,” where locals define Morocco as a unique crossroads of cultures between the Middle East, Africa, and Europe. Ultimately, by using the historic cityscape as proof of Morocco\u27s authentic and enduring cosmopolitanism, these coalitions view present-day globalization as reinforcing Moroccan identity. This pushes back against the widely-held idea that globalization erodes national borders and identity

"Etched in Stone" / "Outlined in Shadows": The Twentieth-Century Lives of American Sephardic Cemeteries

This project investigates conceptualizations of American Jewishness through the twentieth century by tracing the dynamic ‘lives’ of Sephardic cemeteries in New York City and Newport, Rhode Island. It brings the fields of memory and cemetery studies into conversation with histories of Sephardic identity-making in America. I posit cemeteries as archives and methodological touchstones, arguing that they were loci of encounters between Iberian, Ottoman, and Ashkenazic Jews at key moments in the twentieth century. As I demonstrate, these sites embodied the dynamism of Sephardic self-conception in the United States in a way that makes them critical spaces for the study of untold histories today. I look to commemorations, tensions, and forms of neglect in these cemeteries to better understand how the sites were shaped by changing Jewish existences and how they, too, transformed the lives and memories of American Jews

Engineered Neuronal Circuits: A New Platform for Studying the Role of Modular Topology

Neuron–glia cultures serve as a valuable model system for exploring the bio-molecular activity of single cells. Since neurons in culture can be conveniently recorded with great fidelity from many sites simultaneously, it has long been suggested that uniform cultured neurons may also be used to investigate network-level mechanisms pertinent to information processing, activity propagation, memory, and learning. But how much of the functionality of neural circuits can be retained in vitro remains an open question. Recent studies utilizing patterned networks suggest that they provide a most useful platform to address fundamental questions in neuroscience. Here we review recent efforts in the realm of patterned networks’ activity investigations. We give a brief overview of the patterning methods and experimental approaches commonly employed in the field, and summarize the main results reported in the literature. The general picture that emerges from these reports indicates that patterned networks with uniform connectivity do not exhibit unique activity patterns. Rather, their activity is very similar to that of unpatterned uniform networks. However, by breaking the connectivity homogeneity, using a modular architecture, it is possible to introduce pronounced topology-related gating and delay effects. These findings suggest that patterned cultured networks may serve as a new platform for studying the role of modularity in neuronal circuits

De la censure à l'ouverture Les médias de la Réunion, Maurice et Madagascar

International audienceUne presse pluraliste et qui affirme son indépendance, des monopoles d'État battus en brèche par des radios et des télévisions privées, une profusion de chaînes satellitaires et des supports en ligne : les médias d'information des trois îles semblent libérés des tutelles d'antan. En les observant de plus près et sous un angle historique, on peut toutefois nuancer le constat. Depuis les premières feuilles religieuses, jusqu'à la libéralisation récente du secteur audiovisuel, en passant par les supports autonomistes ou nationalistes, la presse écrite et parlée de ces trois îles reflète bien une histoire commune. La Réunion, Maurice et Madagascar ont partagé les épisodes des colonisations française et (pour les deux premières) britannique. Elles ont aujourd'hui emprunté des chemins statutaires différents. Mais, concernant leurs médias, souvent contrôlés voire muselés au cours de leur histoire, on repère des processus identiques d'ouverture qui se produisent avec un décalage de quelques années. Dans ces territoires insulaires, presse et médias d'information sont liés aux contextes sociétaux. Nous nous limiterons, dans le cadre de cet article, à une simple évocation de quelques événements clés, constitutifs de l'émergence de ces espaces publics médiatiques de l'océan Indien

La presse quotidienne régionale, P.Q.R., acteur social local : analyse d'un discours de presse : le cas du "Quotidien de La Réunion", 1976-1997

Ce travail a cherché à mettre en évidence le rôle d'acteur social local que joue un quotidien local au sein d'une société particulière : l'île de La Réunion. Il s'agit de la monographie d'un média, Le "Quotidien de La Réunion", mis en contexte sur une période de 21 ans (1976-1997). Le cadre théorique général, retenu pour traiter cette étude de cas, s'intéresse aux problématiques de la construction de l'événement et du traitement des mouvements sociaux par les médias. Pour verifier l'hypothèse selon laquelle un journal local occupe bien une position d'acteur social se positionnant lors de mouvements sociaux, la méthodologie adoptée a été celle d'une analyse de discours et de mise en forme journalistiques, d'inspiration essentiellement sémiologique. Un corpus d'articles a été traité qui compare la relation par le quotidien de trois mouvements : l'élan de 1977 pour sauver le "jeune" Quotidien, le mouvement de soutien à "Télé FreeDom" (1991) et la mobilisation des fonctionnaires et des étudiants de 1997. L'analyse des procédés d'argumentation et de rhétorique propres à la stratégie éditoriale du journal a ainsi permis de dégager ses propres valeurs et ses positionnements sur la scène locale, tout en soulignat certaines contradictions entre "principes" rédactionnels et pratiques journalistiques. Ce travail de recherche a reçu le prix de la meilleure thèse 1999This work sought to highlight the role of local social actor whom a local daily within a particular company plays: the island of Réunion....

Reliable Sequential Activation of Neural Assemblies by Single Pyramidal Cells in a Three-Layered Cortex

Recent studies reveal the occasional impact of single neurons on surround firing statistics and even simple behaviors. Exploiting the advantages of a simple cortex, we examined the influence of single pyramidal neurons on surrounding cortical circuits. Brief activation of single neurons triggered reliable sequences of firing in tens of other excitatory and inhibitory cortical neurons, reflecting cascading activity through local networks, as indicated by delayed yet precisely timed polysynaptic subthreshold potentials. The evoked patterns were specific to the pyramidal cell of origin, extended over hundreds of micrometers from their source, and unfolded over up to 200 ms. Simultaneous activation of pyramidal cell pairs indicated balanced control of population activity, preventing paroxysmal amplification. Single cortical pyramidal neurons can thus trigger reliable postsynaptic activity that can propagate in a reliable fashion through cortex, generating rapidly evolving and non-random firing sequences reminiscent of those observed in mammalian hippocampus during "replay" and in avian song circuits

Grupo de viviendas en Nazareth

Nowadays Nazareth is a small religious town, with many churches and convents, but lacking altogether any quality that might rememorate its great traditions of the past. All that remains is its location: the adaptation of the buildings to the ground topography, and also perhaps the fact that the majority of its Arab dwellers give it a certain flavour, typical of the region. Not only at Jerusalem and Nazareth, but also at all sites of great historical or religious significance, it is a government requirement that local stone shall be employed for building, and so enhance the regional architectural tradition, for the benefit of the tourist. In consonance with the above two circumstances, the architects Sharon and Idelson have designed this housing project taking great care over the orientation, relationship to the sunrays, scenery and changes in the ground level. There are three different distribution patterns in this estate: each corresponds to a straightforward layout, and allows for cross ventilation of the various rooms. This is an important feature in the warm climate of this region.Nazareth es hoy una pequeña ciudad religiosa llena de iglesias y conventos, pero sin ningún sabor tradicional y muy poca ambientación en su propia historia. Lo único que queda es su situación, el acoplamiento de las edificaciones a la topografía del terreno y u n a mayoría árabe en el número de sus habitantes, que le dan cierto tipismo. Hoy día, t anto en Jerusalén como en Nazareth y en todos los lugares con tradición histórica y religiosa, el Gobierno obliga a utilizar la piedra, en la construcción con vistas a la ambientación para el turismo. Basándose en estos dos prefijos, Sharon e Idelson han proyectado esta urbanización cuidando la orientación, el soleamiento y adaptación de las casas a las curvas de nivel, con tres tipos de viviendas de plantas sencillas, de fácil distribución y con ventilación cruzada, lo cual es muy importante dado el clima cálido de la región