Integrated support structure

This Major Qualifying Project is part of the Advanced Space Design Program at WPI. The goal is to design a support structure for a NASA GetAway Special experimental canister. The payload integration, weight, volume, and structural integrity of the canister as specified by NASA guidelines were studied. The end result is a complete set of design drawings with interface drawings and data to specify the design and leave a base on which the next group can concentrate

Heart enhancers with deeply conserved regulatory activity are established early in zebrafish development.

During the phylotypic period, embryos from different genera show similar gene expression patterns, implying common regulatory mechanisms. Here we set out to identify enhancers involved in the initial events of cardiogenesis, which occurs during the phylotypic period. We isolate early cardiac progenitor cells from zebrafish embryos and characterize 3838 open chromatin regions specific to this cell population. Of these regions, 162 overlap with conserved non-coding elements (CNEs) that also map to open chromatin regions in human. Most of the zebrafish conserved open chromatin elements tested drive gene expression in the developing heart. Despite modest sequence identity, human orthologous open chromatin regions recapitulate the spatial temporal expression patterns of the zebrafish sequence, potentially providing a basis for phylotypic gene expression patterns. Genome-wide, we discover 5598 zebrafish-human conserved open chromatin regions, suggesting that a diverse repertoire of ancient enhancers is established prior to organogenesis and the phylotypic period

Non-equilibrium states of a photon cavity pumped by an atomic beam

We consider a beam of two-level randomly excited atoms that pass one-by-one through a one-mode cavity. We show that in the case of an ideal cavity, i.e. no leaking of photons from the cavity, the pumping by the beam leads to an unlimited increase in the photon number in the cavity. We derive an expression for the mean photon number for all times. Taking into account leaking of the cavity, we prove that the mean photon number in the cavity stabilizes in time. The limiting state of the cavity in this case exists and it is independent of the initial state. We calculate the characteristic functional of this non-quasi-free non-equilibrium state. We also calculate the energy flux in both the ideal and open cavity and the entropy production for the ideal cavity.Comment: Corrected energy production calculations and made some changes to ease the readin

Analyses of femtosecond laser ablation of Ti, Zr, Hf

Femtosecond laser ablation of Ti, Zr and Hf has been investigated by means of in-situ plasma diagnostics. Fast plasma imaging with the aid of an intensified charged coupled device (ICCD) camera was used to characterise the plasma plume expansion on a nanosecond time scale. Time- and spaceresolved optical emission spectroscopy was employed to perform time-of-flight measurements of ions and neutral atoms. It is shown that two plasma components with different expansion velocities are generated by the ultra-short laser ablation process. The expansion behaviour of these two components has been analysed as a function of laser fluence and target material. The results are discussed in terms of mechanisms responsible for ultra-short laser ablation

Us and them: Intergroup failures of empathy

People are often motivated to increase others' positive experiences and to alleviate others' suffering. These tendencies to care about and help one another form the foundation of human society. When the target is an outgroup member, however, people may have powerful motivations not to care about or help that “other.” In such cases, empathic responses are rare and fragile; it is easy to disrupt the chain from perception of suffering to motivation to alleviate the suffering to actual helping. We highlight recent interdisciplinary research demonstrating that outgroup members' suffering elicits dampened empathic responses as compared to ingroup members' suffering. We consider an alternative to empathy in the context of intergroup competition: schadenfreude—pleasure at others' pain. Finally, we review recent investigations of intergroup-conflict interventions that attempt to increase empathy for outgroups. We propose that researchers across the range of psychological sciences stand to gain a better understanding of the foundations of empathy by studying its limitations.Princeton University (Charlotte Elizabeth Procter Fellowship)Alliance of Civilizations (Media Fund)United States. Air Force Office of Scientific Research (grant #N000140910845

Nouveau concept de séchage et de fumage artisanal des aliments : application en milieu de pêche artisanale au Gabon

L’objet de cette étude est de présenter la conception détaillée et la fabrication d’un fumoir à poissons dont les spécificités permettent de répondre aux besoins de PED (pays en développement) côtiers tropicaux liés au traitement de poissons fraîchement péchés. Cette technique de séchage et fumage correspond à un mode de conservation traditionnel en Afrique subsaharienne et permet l’exportation des produits finis. Le dispositif de fumage proposé ici est autonome en ce sens qu’il fonctionne sans électricité et ne nécessite que l’utilisation de bois de combustion et de bois de pyrolyse ; il est de plus modulaire et réalisable avec les matériaux et les outils standards de la maçonnerie et de la chaudronnerie. Il permet de séparer en deux phases distinctes, les opérations de séchage et de fumage. Le séchage des poissons se fait par convection, conduction et rayonnement à partir des conduites de fumées. De ce fait, nous avons une chaleur uniforme au sein de l'enceinte. Le système de fumage permet d'obtenir une teneur des benzo (a) pyrène recommandé par les organismes internationaux.Mots-clés : bois, conception, fumage, PED, poissons, séchage.New concept of drying and smoking of artisanal foods : application in middle of artisanal fishing in GabonThe purpose of this study is to present the detailed design and construction of a fish smokehouse whose characteristics can meet the needs of tropical coastal developing countries related to the treatment of freshly caught fish. This technique of drying and smoking is a traditional way of conservation in subSaharan Africa and allows the export of finished products. The smoking device proposed here is autonomous in the sense that it works without electricity and requires only the wooden use of combustion and wood of pyrolysis; it is of more modular and built with materials and standard tools of the masonry and the boilermaking. He allows to separate in two different phases, the operations of drying and smoking. The drying of fishes is made by convection, conduction and radiation with smoke ducts. Therefore, we have a uniform heat within the smokehouse. The system of smoking allows to obtain a content of benzo ( a ) pyrène recommended by the international bodies.Keywords : wood, design, smoking, PED, fish, drying

Transcriptomic characterization of bud dormancy in apple.

Resumo

Scattering Theory Approach to Random Schroedinger Operators in One Dimension

Methods from scattering theory are introduced to analyze random Schroedinger operators in one dimension by applying a volume cutoff to the potential. The key ingredient is the Lifshitz-Krein spectral shift function, which is related to the scattering phase by the theorem of Birman and Krein. The spectral shift density is defined as the "thermodynamic limit" of the spectral shift function per unit length of the interaction region. This density is shown to be equal to the difference of the densities of states for the free and the interacting Hamiltonians. Based on this construction, we give a new proof of the Thouless formula. We provide a prescription how to obtain the Lyapunov exponent from the scattering matrix, which suggest a way how to extend this notion to the higher dimensional case. This prescription also allows a characterization of those energies which have vanishing Lyapunov exponent.Comment: 1 figur