Coping with loss: cell adaptation to cytoskeleton disruption

Unravelling the role of cytoskeleton regulators may be complicated by adaptations to experimental manipulations. In this issue of Developmental Cell, Cerikan et al. (2016) reveal how acute effects of DOCK6 RhoGEF depletion on RAC1 and CDC42 activation are reversed over time by compensatory mechanisms that re-establish cellular homeostasis

Emissivity coatings for low-temperature space radiators Quarterly progress report no. 1, 1 Jul. - 30 Sep. 1965

Emissivity coatings for low temperature spacecraft radiator

Coarsening of Topological Defects in Oscillating Systems with Quenched Disorder

We use large scale simulations to study interacting particles in two dimensions in the presence of both an ac drive and quenched disorder. As a function of ac amplitude, there is a crossover from a low drive regime where the colloid positions are highly disordered to a higher ac drive regime where the system dynamically reorders. We examine the coarsening of topological defects formed when the system is quenched from a disordered low ac amplitude state to a high ac amplitude state. When the quench is performed close to the disorder-order crossover, the defect density decays with time as a power law with \alpha = 1/4 to 1/3. For deep quenches, in which the ac drive is increased to high values such that the dynamical shaking temperature is strongly reduced, we observe a logarithmic decay of the defect density into a grain boundary dominated state. We find a similar logarithmic decay of defect density in systems containing no pinning. We specifically demonstrate these effects for vortices in thin film superconductors, and discuss implications for dynamical reordering transition studies in these systems.Comment: 7 pages, 8 postscript figures; this extended version to appear in Phys. Rev.

The development of an advanced system to cool a man in a pressure suit

Conductive cooling system for cooling man in pressurized space sui

Vortex configurations and dynamics in elliptical pinning sites for high matching fields

Using numerical simulations we study the configurations, dynamics, and melting properties of vortex lattices interacting with elliptical pinning sites at integer matching fields with as many as 27 vortices per pin. Our pinning model is based on a recently produced experimental system [G. Karapetrov et al., Phys. Rev. Lett. 95, 167002 (2005)], and the vortex configurations we obtain match well with experimental vortex images from the same system. We find that the strong pinning sites capture more than one vortex each, and that the saturation number of vortices residing in a pin increases with applied field due to the pressure from the surrounding vortices. At high matching fields, the vortices in the intestitial regions form a disordered triangular lattice. We measure the depinning thresholds for both the x and y directions, and find distinctive dynamical responses along with highly anisotropic thresholds. For melting of the vortex configurations under zero applied current, we find multi-step melting transitions in which the interstitial vortices melt at a much lower temperature than the pinned vortices. We associate this with signatures in the specific heat.Comment: 11 pages, 13 postscript figure

A cell-permeable biscyclooctyne as a novel probe for the identification of protein sulfenic acids

Reactive oxygen species act as important second messengers in cell signaling and homeostasis through the oxidation of protein thiols. However, the dynamic nature of protein oxidation and the lack of sensitivity of existing molecular probes have hindered our understanding of such reactions; therefore, new tools are required to address these challenges. We designed a bifunctional variant of the strained bicyclo[6.1.0]nonyne (BCN-E-BCN) that enables the tagging of intracellular protein sulfenic acids for biorthogonal copper-free click chemistry. In validation studies, BCN-E-BCN binds the sulfenylated form of the actin-severing protein cofilin, while mutation of the cognate cysteine residues abrogates its binding. BCN-E-BCN is cell permeable and reacts rapidly with cysteine sulfenic acids in cultured cells. Using different azide-tagged conjugates, we demonstrate that BCN-E-BCN can be used in various applications for the detection of sulfenylated proteins. Remarkably, cycloaddition of an azide-tagged fluorophore to BCN-E-BCN labelled proteins produced in vivo can be visualized by fluorescence microscopy to reveal their subcellular localization. These findings demonstrate a novel and multifaceted approach to the detection and trapping of sulfenic acids

Troposphere-stratosphere (surface-55 km) monthly general circulation statistics for the Northern Hemisphere-four year averages

This report presents four year averages of monthly mean Northern Hemisphere general circulation statistics for the period from 1 December 1978 through 30 November 1982. Computations start with daily maps of temperature for 18 pressure levels between 1000 and 0.4 mb that were supplied by NOAA/NMC. Geopotential height and geostrophic wind are constructed using the hydrostatic and geostrophic formulae. Fields presented in this report are zonally averaged temperature, mean zonal wind, and amplitude and phase of the planetary waves in geopotential height with zonal wavenumbers 1-3. The northward fluxes of heat and eastward momentum by the standing and transient eddies along with their wavenumber decomposition and Eliassen-Palm flux propagation vectors and divergences by the standing and transient eddies along with their wavenumber decomposition are also given. Large annual and interannual variations are found in each quantity especially in the stratosphere in accordance with the changes in the planetary wave activity. The results are shown both in graphic and tabular form

Holiday Foods with a Honey Flavor

Substituting honey for some of the sugar normally used in baking keeps food moist longer, gives a unique flavor, and prevents crystallization

Superconducting Fluxon Pumps and Lenses

We study stochastic transport of fluxons in superconductors by alternating current (AC) rectification. Our simulated system provides a fluxon pump, "lens", or fluxon "rectifier" because the applied electrical AC is transformed into a net DC motion of fluxons. Thermal fluctuations and the asymmetry of the ratchet channel walls induce this "diode" effect, which can have important applications in devices, like SQUID magnetometers, and for fluxon optics, including convex and concave fluxon lenses. Certain features are unique to this novel two-dimensional (2D) geometric pump, and different from the previously studied 1D ratchets.Comment: Phys. Rev. Lett. 83, in press (1999); 4 pages, 5 .gif figures; figures also available at http://www-personal.engin.umich.edu/~nori/ratche