Theoretical Study of Radiant Heat Exchange for Non-gray Non-diffuse Surfaces in a Space Environment Semiannual Status Report No. 2, Aug. 1965 - Feb. 1966

Bi-directional reflectance models for describing distribution of reflected energy from rough metallic spacecraft surface

Theoretical study of radiant heat exchange for non-gray non-diffuse surfaces in a space environment Semiannual status report no. 3, Feb. - Jul. 1966

Radiant heat exchange for nongray nondiffuse surfaces in space environmen

Radiant heat exchange in a space environment Scientific technical report, 1 Feb. - 31 Jul. 1970

Spectral and directional surface property effects on radiant heat transfer in space environmen

Radiant heat exchange in a space environment Scientific technical report, 1 Aug. 1969 - 31 Jan. 1970

Spectral surface property effects on radiant heat transfer in aerospace environmen

Radiant heat exchange in a space environment Scientific technical report, 1 Feb. - 31 Jul. 1969

Analytical methods development for predicting radiant heat transfer and temperature of engineering surfaces in space environmen

Mitochondrial cristae remodelling is associated with disrupted OPA1 oligomerisation in the Huntington's disease R6/2 fragment model

There is evidence of an imbalance of mitochondrial fission and fusion in patients with Huntington's disease (HD) and HD animal models. Fission and fusion are important for mitochondrial homeostasis including mitochondrial DNA (mtDNA) maintenance and may be relevant for the selective striatal mtDNA depletion that we observed in the R6/2 fragment HD mouse model. We aimed to investigate the fission/fusion balance and the integrity of the mitochondrial membrane system in cortex and striatum of end-stage R6/2 mice and wild-type animals. Mitochondrial morphology was determined using electron microscopy, and transcript and protein levels of factors that play a key role in fission and fusion, including DRP1, mitofusin 1 and 2, mitofilin and OPA1, and cytochrome c and caspase 3 were assessed by RT-qPCR and immunoblotting. OPA1 oligomerisation was evaluated using blue native gels. In striatum and cortex of R6/2 mice, mitochondrial cristae morphology was abnormal. Mitofilin and the overall levels of the fission and fusion factors were unaffected; however, OPA1 oligomerisation was abnormal in striatum and cortex of R6/2 mice. Mitochondrial and cytoplasmic cytochrome c levels were similar in R6/2 and wild-type mice with no significant increase of activated caspase 3. Our results indicate that the integrity of the mitochondrial cristae is compromised in striatum and cortex of the R6/2 mice and that this is most likely caused by impaired OPA1 oligomerisation

Structural, mechanistic and functional insight into gliotoxin bis-thiomethylation in Aspergillus fumigatus.

Gliotoxin is an epipolythiodioxopiperazine (ETP) class toxin, contains a disulfide bridge that mediates its toxic effects via redox cycling and is produced by the opportunistic fungal pathogen Aspergillus fumigatus Self-resistance against gliotoxin is effected by the gliotoxin oxidase GliT, and attenuation of gliotoxin biosynthesis is catalysed by gliotoxin S-methyltransferase GtmA. Here we describe the X-ray crystal structures of GtmA-apo (1.66 Å), GtmA complexed to S-adenosylhomocysteine (1.33 Å) and GtmA complexed to S-adenosylmethionine (2.28 Å), providing mechanistic insights into this important biotransformation. We further reveal that simultaneous elimination of the ability of A. fumigatus to dissipate highly reactive dithiol gliotoxin, via deletion of GliT and GtmA, results in the most significant hypersensitivity to exogenous gliotoxin observed to date. Indeed, quantitative proteomic analysis of ΔgliT::ΔgtmA reveals an uncontrolled over-activation of the gli-cluster upon gliotoxin exposure. The data presented herein reveal, for the first time, the extreme risk associated with intracellular dithiol gliotoxin biosynthesis-in the absence of an efficient dismutation capacity. Significantly, a previously concealed protective role for GtmA and functionality of ETP bis-thiomethylation as an ancestral protection strategy against dithiol compounds is now evident

Signature of Electronic Correlations in the Optical Conductivity of the Doped Semiconductor Si:P

Electronic transport in highly doped but still insulating silicon at low temperatures is dominated by hopping between localized states; it serves as a model system of a disordered solid for which the electronic interaction can be investigated. We have studied the frequency-dependent conductivity of phosphorus-doped silicon in the THz frequency range (30 GHz to 3 THz) at low temperatures $T\geq 1.8$ K. The crossover in the optical conductivity from a linear to a quadratic frequency dependence as predicted by Efros and Shklovskii is observed qualitatively; however, the simple model does not lead to a quantitative agreement. Covering a large range of donor concentration, our temperature- and frequency-dependent investigations reveal that electronic correlation effects between the localized states play an important and complex role at low temperatures. In particular we find a super-linear frequency dependence of the conductivity that highlights the influence of the density of states, i.e. the Coulomb gap, on the optical conductivity. When approaching the metal-to-insulator transition by increasing doping concentration, the dielectric constant and the localization length exhibit critical behavior.Comment: 9 pages, 8 figures, 1 tabl

Vascular white matter lesions negatively correlate with brain metastases in malignant melanoma - results from a retrospective comparative analysis

Brain metastasis (BM) is a major complication of different cancers. There is increasing evidence for influence of vascular factors on BM in patients with non-small cell lung cancer (NSCLC). It is not known if the same is true for other tumors that might rely on different forms of vasculogenesis. The objective of this retrospective study was to evaluate a possible negative association of vascular white matter lesions and vascular risk factors (vasRF) with brain metastases in patients with melanoma

Laminar natural convection over a slender vertical frustum of a cone

The problem of laminar, natural convection flow over a slender frustum of a cone is treated in this paper. The governing differential equations are solved by a combination of quasi-linearization and finite-difference methods. Numerical solutions are obtained for Pr=0.7 and for a range of values of the transverse curvature parameter. It is shown that the effect of transverse curvature is of great significance in such flows. In diesem Bericht ist das Problem der laminaren natürlichen Konvektionsströmung an einem dünnen Kegelstumpf behandelt. Die maßgebliche Differentialgleichung ist durch eine Verbindung von Quasilinearisation und Differenzenverfahren gelöst. Eine numerische Lösung für Pr=0.7 wird für verschiedene Werte eines Krümmungsparameters angegeben. Es ist gezeigt, daß in solchen Strömungen dieser Krümmungsparameter eine große Bedeutung besitzt.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46649/1/231_2005_Article_BF01002323.pd