Kidney cell electrophoresis in space flight: Rationale, methods, results and flow cytometry applications

Cultures of human embryonic kidney cells consistently contain an electrophoretically separable subpopulation of cells that produce high levels of urokinase and have an electrophoretic mobility about 85 percent as high as that of the most mobile human embryonic kidney cells. This subpopulation is rich in large epithelioid cells that have relatively little internal structure. When resolution and throughput are adequate, free fluid electrophoresis can be used to isolate a broad band of low mobility cells which also produces high levels of plasminogen activators (PAs). In the course of performing this, it was discovered that all electrophoretic subpopulations of cultured human embryonic kidney cells produce some PAs and that separate subpopulations produce high quantities of different types of PA's. This information and the development of sensitive assays for this project have provided new insights into cell secretion mechanisms related to fibrinolysis. These advances would probably not have been made without the NASA program to explore fundamental questions of free fluid electrophoresis in space

Neuroinflammation by cytotoxic T-lymphocytes impairs retrograde axonal transport in an oligodendrocyte mutant mouse

Mice overexpressing proteolipid protein (PLP) develop a leukodystrophy-like disease involving cytotoxic, CD8+ T-lymphocytes. Here we show that these cytotoxic T-lymphocytes perturb retrograde axonal transport. Using fluorogold stereotactically injected into the colliculus superior, we found that PLP overexpression in oligodendrocytes led to significantly reduced retrograde axonal transport in retina ganglion cell axons. We also observed an accumulation of mitochondria in the juxtaparanodal axonal swellings, indicative for a disturbed axonal transport. PLP overexpression in the absence of T-lymphocytes rescued retrograde axonal transport defects and abolished axonal swellings. Bone marrow transfer from wildtype mice, but not from perforin- or granzyme B-deficient mutants, into lymphocyte-deficient PLP mutant mice led again to impaired axonal transport and the formation of axonal swellings, which are predominantly located at the juxtaparanodal region. This demonstrates that the adaptive immune system, including cytotoxic T-lymphocytes which release perforin and granzyme B, are necessary to perturb axonal integrity in the PLP-transgenic disease model. Based on our observations, so far not attended molecular and cellular players belonging to the immune system should be considered to understand pathogenesis in inherited myelin disorders with progressive axonal damage

Axially Compressed Cylindrical Shell Containing Axisymmetric Random Imperfections:

ABSTRACT This paper presents the comparison of reliability technique that employ Fourier series representations of random asymmetric imperfections in axially compressed cylindrical shell with evaluations prescribed by ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 and 2. The ultimate goal of the reliability type technique is to predict the buckling load associated with the axially compressed cylindrical shell. Initial geometric imperfections have significant effect on the load carrying capacity of asymmetrical cylindrical shells. Fourier decomposition is used to interpret imperfections as structural features can be easily related to the different components of imperfections. The initial functional description of the imperfections consists of an axisymmetric portion and a deviant portion appearing as a double Fourier series. The representation of initial geometrical imperfections in the cylindrical shell requires the determination of appropriate Fourier coefficients. The mean vector and the variance-covariance matrix of Fourier coefficients are calculated from the simulated shell profiles. Multi-mode analysis are expanded to evaluate a large number of potential buckling modes for both predefined geometries and associated asymmetric imperfections as a function of position within a given cylindrical shell. Large number of shells thus created can be used to calculate buckling stress for each shell. The probability of the ultimate buckling stress exceeding a predefined threshold stress can also be calculated. Keywords: Buckling; Asymmetric Imperfections; Fourier Series; Cylindrical Shell. NOMENCLATURE λ = Non-dimensional buckling load μ = Poisson"s ratio ξ i = Magnitude of imperfection as a fractional value of shell thickness θ = Non-dimensional number associated with the circumferential coordinates ξ = Non-dimensional number associated with the axial coordinates σ A (ξ) = Elements of Variance-covariance matrix C w0 (ξ 1 ,θ 1 ,ξ 2 ,θ 2 ) = Auto-covariance function k = Number of half waves in axial direction l = Number of full waves in circumferential direction P cl = Classical buckling load of a perfect shell P cr = Critical buckling load of a shell with imperfections Proceedings of IMECE2008 2008 ASME International Mechanical Engineering Congress and Exposition October 31-November 6, 2008, Boston, Massachusetts, USA Copyright©2008 by ASME 2 R = Radius of the shell E = Young"s Modulus L = Length of the shell t = Wall thickness of the shell D 0 = Outside diameter of the shell W n (ξ,θ) = Initial imperfection function IMECE2008-6879

Magnetic irreversibility and Verwey transition in nano-crystalline bacterial magnetite

The magnetic properties of biologically-produced magnetite nanocrystals biomineralized by four different magnetotactic bacteria were compared to those of synthetic magnetite nanocrystals and large, high quality single crystals. The magnetic feature at the Verwey temperature, $T_{V}$, was clearly seen in all nanocrystals, although its sharpness depended on the shape of individual nanoparticles and whether or not the particles were arranged in magnetosome chains. The transition was broader in the individual superparamagnetic nanoparticles for which $T_{B}<T_{V}$, where $T_{B}$ is the superparamagnetic blocking temperature. For the nanocrystals organized in chains, the effective blocking temperature $T_{B}>T_{V}$ and the Verwey transition is sharply defined. No correlation between the particle size and $T_{V}$ was found. Furthermore, measurements of $M(H,T,time)$ suggest that magnetosome chains behave as long magnetic dipoles where the local magnetic field is directed along the chain and this result confirms that time-logarithmic magnetic relaxation is due to the collective (dipolar) nature of the barrier for magnetic moment reorientation

Well Logging Results from the Newark Rift Basin Coring Project

Wireline logs were acquired at seven sites in the Newark Rift basin using dipmeter, gamma ray, resistivity, velocity, porosity, density, magnetic susceptibility, temperature, and acoustic televiewer tools. The logs indicate that the formations are clay rich and dip on average 9°N-NW. Densities are relatively constant (2.60-2.80 glee) and compressional velocities vary from 4.2-5.5 km/s. Thin uranium-rich layers and basalt flows are clearly delineated. The boreholes are mostly in-gauge, but deviated, and borehole temperature gradients vary between 15 to 26°C/km. These data are potentially useful as indicators of fluid flow and regional stress, lithologic cycles, and for core orientation in the Newark Rift basin

GCIP water and energy budget synthesis (WEBS)

As part of the World Climate Research Program\u27s (WCRPs) Global Energy and Water-Cycle Experiment (GEWEX) Continental-scale International Project (GCIP), a preliminary water and energy budget synthesis (WEBS) was developed for the period 1996–1999 from the “best available” observations and models. Besides this summary paper, a companion CD-ROM with more extensive discussion, figures, tables, and raw data is available to the interested researcher from the GEWEX project office, the GAPP project office, or the first author. An updated online version of the CD-ROM is also available at http://ecpc.ucsd.edu/gcip/webs.htm/. Observations cannot adequately characterize or “close” budgets since too many fundamental processes are missing. Models that properly represent the many complicated atmospheric and near-surface interactions are also required. This preliminary synthesis therefore included a representative global general circulation model, regional climate model, and a macroscale hydrologic model as well as a global reanalysis and a regional analysis. By the qualitative agreement among the models and available observations, it did appear that we now qualitatively understand water and energy budgets of the Mississippi River Basin. However, there is still much quantitative uncertainty. In that regard, there did appear to be a clear advantage to using a regional analysis over a global analysis or a regional simulation over a global simulation to describe the Mississippi River Basin water and energy budgets. There also appeared to be some advantage to using a macroscale hydrologic model for at least the surface water budgets

An aerosol challenge model of tuberculosis in Mauritian cynomolgus macaques

Background New interventions for tuberculosis are urgently needed. Non-human primate (NHP) models provide the most relevant pre-clinical models of human disease and play a critical role in vaccine development. Models utilising Asian cynomolgus macaque populations are well established but the restricted genetic diversity of the Mauritian cynomolgus macaques may be of added value. Methods Mauritian cynomolgus macaques were exposed to a range of doses of M. tuberculosis delivered by aerosol, and the outcome was assessed using clinical, imaging and pathology-based measures. Results All macaques developed characteristic clinical signs and disease features of tuberculosis (TB). Disease burden and the ability to control disease were dependent on exposure dose. Mauritian cynomolgus macaques showed less variation in pulmonary disease burden and total gross pathology scores within exposure dose groups than either Indian rhesus macaques or Chinese cynomolgus macaques Conclusions The genetic homogeneity of Mauritian cynomolgus macaques makes them a potentially useful model of human tuberculosis

‘I can die today, I can die tomorrow’: lay perceptions of sickle cell disease in Kumasi, Ghana at a point of transition

Objective. To describe the lay meanings of sickle cell disease (SCD) in the Ashanti region of Ghana