Quantum quenches in a spinor condensate

We discuss the ordering of a spin-1 condensate when quenched from its paramagnetic phase to its ferromagnetic phase by reducing magnetic field. We first elucidate the nature of the equilibrium quantum phase transition. Quenching rapidly through this transition reveals XY ordering either at a specific wavevector, or the `light-cone' correlations familiar from relativistic theories, depending on the endpoint of the quench. For a quench proceeding at a finite rate the ordering scale is governed by the Kibble-Zurek mechanism. The creation of vortices through growth of the magnetization fluctuations is also discussed. The long time dynamics again depends on the endpoint, conserving the order parameter in zero field, but not at finite field, with differing exponents for the coarsening of magnetic order. The results are discussed in the light of a recent experiment by Sadler \emph{et al.}Comment: Published versio

Survivorship and Growth of Seedlings and Saplings in Urban Forests

Research in 1993, 2003, and 2013 showed high rates of tree mortality and low rates of recruitment (new trees) in Portland, Oregon’s Forest Park. To determine if the lack of young trees was an urban phenomenon, we added three control sites in the Mount Hood National Forest in 2013. Last summer, seedlings and saplings were measured at all sites in Forest Park, the Ancient Forest Preserve, and at the control sites. Seedlings are trees less than 2 meters tall, and saplings are trees greater than 2 meters tall but having a dbh of less than 10cm. The 2018 data was compared to that collected in 2013. We measured dbh (diameter at breast height) of saplings and the basal area for seedlings, as well as the tree height and the height of the lowest living branch. In 2018, the control sites had significantly more live trees, more coniferous trees, more shade tolerant trees, and more seedlings and saplings. We also found that the seedlings and saplings in 2018 had a greater diameter at the control sites than the urban sites. We found significantly more dead trees in 2018 than 2013 in Forest Park

Understanding the Effects of Moisture on Hot Mix Asphalt (HMA)

Moisture damage in hot mix asphalt (HMA) can lead to deterioration of asphalt pavements (cracking, potholes, and rutting) that effect the ease and safety of travel along roads. One objective of the study was to evaluate the change in functional groups, specifically carbonyl and sulfoxide, of asphalt binder as a result of moisture damage. Changes in functional groups after moisture damage were found, but no direct correlation between asphalt performance and change in functional groups could be identified. The other objective was to design a fiber reinforced mix with resistance against moisture damage. An ideal fiber content of 0.25% fiber by total mass was found and was proven to increase tensile strength of asphalt by more than 20%, both before and after being exposed to moisture damage

Informal and Alternative Economies on the Periphery Of New Orleans during the Early-Nineteenth Century: An Archaeological Inquiry of 16OR180

In summer of 2012 archaeological excavations were conducted at the Iberville Housing Projects in New Orleans, Louisiana. The excavations were conducted in order to gather archaeological data pertaining to the site’s history as part of New Orleans’ notorious vice district, Storyville. During excavation a cache of 765 turquoise glass seed beads was uncovered along the east wall of Test Unit #1. The cache, found at a depth of around 83 cm below the ground surface, suggests, in conjunction with other artifacts found at this level, that the beads were deposited at the site between 1810 and 1830. This cache of seed beads is unique at the site both in its context and in the quantity of beads that were found. The presence of the bead cache suggests that there may have been an active trading economy at the site, as beads similar to those found at the Iberville site are important elements in informal economies of the eighteenth century. This paper discusses the possibility that an alternative or informal reciprocal, non-cash based economy was in operation on the periphery of New Orleans in the early nineteenth century

Functional characterization of synthetic leukotriene B and its stereochemical isomers.

Leukotriene B (LTB), a potent lipid chemotactic factor for neutrophils, is 5S,12R-dihydroxy-6,14-cis,8,10-trans-eicosatetraenoic acid (Fig 1), based upon direct comparison of natural LTB with synthetic 5S,12R-dihydroxy-6,8,10,14-eicosatetraenoic acid (5,12-di-HETE) stereoisomers in three biological assays. Of the six synthetic stereoisomers evaluated, only the 5S,12R,6,14-cis,8,10-trans compound had chemotactic potency for human neutrophils in vitro that was comparable to that of natural LTB, with a concentration of 3 X 10(9-9) M eliciting a one-half maximum response. In contrast, the racemic mixture of 5R,12R- and 5S,12S-6,10-trans,8,14-cis, the racemic mixture of 5S,12R- and 5R,12S-6,10-trans,8,14-cis, the 5S,12R-6,8-trans,10,14-cis, the 5S,12R-6,8,10-trans,14-cis, and the 5S,12S-6,8,10-trans,14-cis stereoisomers required concentrations of 3 X 10(-7) to 1 X 10(-6) M to elicit comparable responses. Only natural LTB and its synthetic counterpart elicited a local neutrophil infiltration when injected into the skin of the rhesus monkey at 10 ng and 100 ng per site. Natural and synthetic LTB at a concentration of 3 X 10(-8) M each provoked an EC25 contractile response of guinea pig pulmonary parenchymal strips in vitro, whereas the other four tested stereoisomers of 5,12-di-HETE were inactive at this concentration. Structure-function analyses suggest that the neutrophil chemotactic activity depends critically upon the C-1 to C-12 domain, including the stereochemistry of the 6-,8-,and 10-olefinic bonds and the presence of both hydroxyl groups

Long wavelength spin dynamics of ferromagnetic condensates

We obtain the equations of motion for a ferromagnetic Bose condensate of arbitrary spin in the long wavelength limit. We find that the magnetization of the condensate is described by a non-trivial modification of the Landau-Lifshitz equation, in which the magnetization is advected by the superfluid velocity. This hydrodynamic description, valid when the condensate wavefunction varies on scales much longer than either the density or spin healing lengths, is physically more transparent than the corresponding time-dependent Gross-Pitaevskii equation. We discuss the conservation laws of the theory and its application to the analysis of the stability of magnetic helices and Larmor precession. Precessional instabilities in particular provide a novel physical signature of dipolar forces. Finally, we discuss the anisotropic spin wave instability observed in the recent experiment of Vengalattore et. al. (Phys. Rev. Lett. 100, 170403, (2008)).Comment: arXiv version contains additional Section V relevant to the experiment of Vengalattore et. al. (Phys. Rev. Lett. 100, 170403, (2008)

The visual standards for the selection and retention of astronauts

Literature search with abstracts on visual performance standards for selection and retention of astronaut

Leukotrienes provide an NFAT-dependent signal that synergizes with IL-33 to activate ILC2s.

Group 2 innate lymphoid cells (ILC2s) and type 2 helper T cells (Th2 cells) are the primary source of interleukin 5 (IL-5) and IL-13 during type 2 (allergic) inflammation in the lung. In Th2 cells, T cell receptor (TCR) signaling activates the transcription factors nuclear factor of activated T cells (NFAT), nuclear factor κB (NF-κB), and activator protein 1 (AP-1) to induce type 2 cytokines. ILC2s lack a TCR and respond instead to locally produced cytokines such as IL-33. Although IL-33 induces AP-1 and NF-κB, NFAT signaling has not been described in ILC2s. In this study, we report a nonredundant NFAT-dependent role for lipid-derived leukotrienes (LTs) in the activation of lung ILC2s. Using cytokine reporter and LT-deficient mice, we find that complete disruption of LT signaling markedly diminishes ILC2 activation and downstream responses during type 2 inflammation. Type 2 responses are equivalently attenuated in IL-33- and LT-deficient mice, and optimal ILC2 activation reflects potent synergy between these pathways. These findings expand our understanding of ILC2 regulation and may have important implications for the treatment of airways disease

A Mansion Of Dreams

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