Increased rate of D1 repair in coral symbionts during bleaching is insufficient to counter accelerated photo-inactivation

We dissect the primary photo-inactivation and the counteracting metabolic repair rates in fragments of the scleractinian coral, Pocillopora damicornis, subjected to a combined stress of a shift to elevated temperature (from 26°C to 32°C) and increased light (from 200 μmol photons m-2 s-1 to 400 μmol photons m-2 s-1) to induce bleaching. During the bleaching treatment the dinoflagellate symbionts showed a 5.5-fold acceleration in their photosystem II (PSII) repair rate constant, demonstrating that they maintain strong metabolic capacity to clear and replace photo-damaged D1 protein at the elevated temperature and light conditions. Nevertheless, the symbionts concurrently suffered a seven-fold increase in the rate constant for PSII photo-inactivation. This rapid photo-inactivation exceeded the PSII repair capacity, therefore tipping the symbionts, and by implication the symbiosis, into net photo-inhibition. Increased photo-inactivation in hospite, rather than an inhibition of PSII repair, is the principle trigger for net photo-inhibition under bleaching conditions. © 2011, by the American Society of Limnology and Oceanography, Inc

Correction to “Interchange instability in the inner magnetosphere associated with geosynchronous particle flux decreases”

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94678/1/grl17909.pd

Magnetic Effects at the Edge of the Solar System: MHD Instabilities, the de Laval nozzle Effect and an Extended Jet

To model the interaction between the solar wind and the interstellar wind, magnetic fields must be included. Recently Opher et al. 2003 found that, by including the solar magnetic field in a 3D high resolution simulation using the University of Michigan BATS-R-US code, a jet-sheet structure forms beyond the solar wind Termination Shock. Here we present an even higher resolution three-dimensional case where the jet extends for $150AU$ beyond the Termination Shock. We discuss the formation of the jet due to a de Laval nozzle effect and it's su bsequent large period oscillation due to magnetohydrodynamic instabilities. To verify the source of the instability, we also perform a simplified two dimensional-geometry magnetohydrodynamic calculation of a plane fluid jet embedded in a neutral sheet with the profiles taken from our 3D simulation. We find remarkable agreement with the full three-dimensional evolution. We compare both simulations and the temporal evolution of the jet showing that the sinuous mode is the dominant mode that develops into a velocity-shear-instability with a growth rate of $5 \times 10^{-9} sec^{-1}=0.027 years^{-1}$. As a result, the outer edge of the heliosphere presents remarkable dynamics, such as turbulent flows caused by the motion of the jet. Further study, e.g., including neutrals and the tilt of the solar rotation from the magnetic axis, is required before we can definitively address how this outer boundary behaves. Already, however, we can say that the magnetic field effects are a major player in this region changing our previous notion of how the solar system ends.Comment: 24 pages, 13 figures, accepted for publication in Astrophysical Journal (2004

Новые методы получения и биологически активные свойства Пиоцианина

Пиоцианин обладает противомикробной, противогрибковой и противоопухолевой активностью. Для изучения этих свойств и поиска дальнейшего применения пиоцианина, был увеличен выход пиоцианина с помощью оптимизации условий культивирования и оптимизации питательной среды.Pyocyanin has antimicrobial, antifungal and antitumor activity. To study these properties and search for further use of pyocyanin, the yield of pyocyanin was increased by optimizing cultivation conditions and optimizing the nutrient medium

A New MHD Code with Adaptive Mesh Refinement and Parallelization for Astrophysics

A new code, named MAP, is written in Fortran language for magnetohydrodynamics (MHD) calculation with the adaptive mesh refinement (AMR) and Message Passing Interface (MPI) parallelization. There are several optional numerical schemes for computing the MHD part, namely, modified Mac Cormack Scheme (MMC), Lax-Friedrichs scheme (LF) and weighted essentially non-oscillatory (WENO) scheme. All of them are second order, two-step, component-wise schemes for hyperbolic conservative equations. The total variation diminishing (TVD) limiters and approximate Riemann solvers are also equipped. A high resolution can be achieved by the hierarchical block-structured AMR mesh. We use the extended generalized Lagrange multiplier (EGLM) MHD equations to reduce the non-divergence free error produced by the scheme in the magnetic induction equation. The numerical algorithms for the non-ideal terms, e.g., the resistivity and the thermal conduction, are also equipped in the MAP code. The details of the AMR and MPI algorithms are described in the paper.Comment: 44 pages, 16 figure

Three-dimensional adaptive evolution of gravitational waves in numerical relativity

Adaptive techniques are crucial for successful numerical modeling of gravitational waves from astrophysical sources such as coalescing compact binaries, since the radiation typically has wavelengths much larger than the scale of the sources. We have carried out an important step toward this goal, the evolution of weak gravitational waves using adaptive mesh refinement in the Einstein equations. The 2-level adaptive simulation is compared with unigrid runs at coarse and fine resolution, and is shown to track closely the features of the fine grid run.Comment: REVTeX, 7 pages, including three figures; submitted to Physical Review

Разработка технологии и проектирование участка сборки-сварки траверсы задней механизированной крепи МКЮ4У.56

Актуальность работы: в данной выпускной квалификационной работе производится проектирование участка сборки-сварки траверсы задней крепи механизированной МКЮ 4У.56. Объектом исследования является процесс изготовления траверсы. В результате данной работы следует получить производство с наибольшей степенью механизации и автоматизации повышающей производительность труда.Relevance of the work: in the final qualifying work is done tooling design and site assembly welding traverses back lining mechanized MKY 4U.56 As a result of this work should be obtained from producing the greatest degree of mechanization and automation increases productivity

Comparison of the open‐closed separatrix in a global magnetospheric simulation with observations: The role of the ring current

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95344/1/jgra20421.pd

Dust–Gas Interrelations In Comets: Observations And Theory

The development of the expanding atmospherefrom the evaporating cometary nucleus has traditionallyfocused on observing and modeling the separatedevelopment of two distinct components, gas and dust,which are coupled dynamically with one another atdistances out to a few tens of cometary radii. In the lastdecade or so, however, direct evidence from observationsand suggestions from theory suggest that the dusty-gascoma is a tightly coupled system where material is transferredbetween the solid and gaseous phase as an importantintegral part of the basic development of the coma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43256/1/11038_2004_Article_239224.pd

MHD Simulation of Comets: The Plasma Environment of Comet Hale–Bopp

MHD simulation results of the interaction of the expanding atmosphere of comet Hale-Bopp with the magnetized solar wind are presented. At the upstream boundary a supersonic and superalfvénic solar wind enters into the simulation box 25 million km upstream of the nucleus.The solar wind is continuously mass loaded with cometaryions originating from the nucleus. The effects of photoionization, recombination andion-neutral frictional drag are taken into account in the model.The governing equations are solved on an adaptively refined unstructured Cartesian grid using our MUSCL-type upwind numerical technique, MAUS-MHD(Multiscale Adaptive Upwind Scheme for MHD). The combination of the adaptive refinement with the MUSCL-scheme allows the entire cometary atmosphere to be modeled, while still resolving both the shock and the diamagnetic cavity of the comet.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43255/1/11038_2004_Article_239216.pd