XSophe-Sophe-XeprView (R). A computer simulation software suite (v. 1.1.3) for the analysis of continuous wave EPR spectra

The XSophe-Sophe-XeprView((R)) computer simulation software suite enables scientists to easily determine spin Hamiltonian parameters from isotropic, randomly oriented and single crystal continuous wave electron paramagnetic resonance (CW EPR) spectra from radicals and isolated paramagnetic metal ion centers or clusters found in metalloproteins, chemical systems and materials science. XSophe provides an X-windows graphical user interface to the Sophe programme and allows: creation of multiple input files, local and remote execution of Sophe, the display of sophelog (output from Sophe) and input parameters/files. Sophe is a sophisticated computer simulation software programme employing a number of innovative technologies including; the Sydney OPera HousE (SOPHE) partition and interpolation schemes, a field segmentation algorithm, the mosaic misorientation linewidth model, parallelization and spectral optimisation. In conjunction with the SOPHE partition scheme and the field segmentation algorithm, the SOPHE interpolation scheme and the mosaic misorientation linewidth model greatly increase the speed of simulations for most spin systems. Employing brute force matrix diagonalization in the simulation of an EPR spectrum from a high spin Cr(III) complex with the spin Hamiltonian parameters g(e) = 2.00, D = 0.10 cm(-1), E/D = 0.25, A(x) = 120.0, A(y) = 120.0, A(z) = 240.0 x 10(-4) cm(-1) requires a SOPHE grid size of N = 400 (to produce a good signal to noise ratio) and takes 229.47 s. In contrast the use of either the SOPHE interpolation scheme or the mosaic misorientation linewidth model requires a SOPHE grid size of only N = 18 and takes 44.08 and 0.79 s, respectively. Results from Sophe are transferred via the Common Object Request Broker Architecture (CORBA) to XSophe and subsequently to XeprView((R)) where the simulated CW EPR spectra (1D and 2D) can be compared to the experimental spectra. Energy level diagrams, transition roadmaps and transition surfaces aid the interpretation of complicated randomly oriented CW EPR spectra and can be viewed with a web browser and an OpenInventor scene graph viewer.

Derivatives of 1,3,5-triamino-1,3,5-trideoxy-cis-inositas versatile pentadentate ligands for protein labeling with Re-186/188. Prelabeling, biodistribution, and X-ray structural studies

The pentadentate H(3)bhci [1,3,5-trideoxy-1,3-bis((2-hydroxybenzyl)amino)-cis-inistol] and its bifunctionalized analogue H(3)bhci-glu-H [1,3,5-trideoxy-1,3-bis((2-hydroxybenzyl)amino)-5-glutaramido-cis-inositol] were synthesized, and their coordination chemistry was investigated with inactive rhenium, with no carrier added Re-188 and with carrier added Re-186. The neutral Re(V) complexes [ReO-(bhci)] and [ReO(bhci-glu-H)] are formed in good yields starting from [ReOCl3(P(C6H5)(3))(2)] or in quantitative yield directly from [(ReO4)-Re-186/188](-) in aqueous solution by reduction with Sn(II) or Sn(0). The X-ray structures of [ReO(bhci)] and [ReO(bhci-glu-H)] were elucidated revealing pentadentate side on coordination of the ligands to the Re=O core. The basic cyclohexane frame adopts a chair form in the case of [ReO(bhci)] and a twisted boat form in the case of [ReO(bhci-glu-H)]. [ReO(bhci)] crystallizes in the monoclinic space group C2/c with a = 27.425(3), b = 14.185(1), c = 19.047(2) Angstrom, and beta = 103.64(2)degrees and [ReO(bhci-glu-H)] in the monoclinic space group P2(1)/c with a = 13.056(3), b = 10.180(1), c = 22.378(5) Angstrom and beta = 98.205(9)degrees Both Re-188 complexes are stable in human serum for at least 3 days without decomposition. After injection into mice, [ReO(bhci-glu)](-) is readily excreted through the intestines, while [ReO(bhci)] is excreted by intestines, liver, and the kidneys. TLC investigations of the urine showed exclusively the complexes [ReO(bhci-glu-H)] and [ReO(bhci)], respectively, and no decomposition products. For derivatization of antibodies, the carboxylic group of [ReO(bhci-glu-H)] was activated with N-hydroxysuccinimide, which required unusually vigorous reaction conditions (heating). The anti colon cancer antibody mAb-35 [IgG and F(ab')(2) fragment] was labeled with [(ReO)-Re-186/188(bhci-glu)] to a specific activity of up to 1.5 mCi/mg (55 MBq/mg) with full retention of immunoreactivity. Labeling yields followed pseudo-first-order kinetics in antibody concentration with the ratio of rates between aminolysis and hydrolysis being about 2. Biodistributions of Re-186-labeled intact mAb-35 as well as of its F(ab')(2) fragment in tumor-bearing nude mice revealed good uptake by the tumor with only low accumulation of radioactivity in normal tissue.

5-cycle systems of K-v-F with a hole

Recently the problem of the existence of a 5-cycle system of K-v with a hole of size u was completely solved. In this paper we prove necessary and sufficient conditions on v and u for the existence of a 5-cycle system of K-v - F, with a hole of size u.

Red Parkes quasars: Evidence for soft X-ray absorption

The Parkes Half-Jansky Flat-Spectrum Sample contains a large number of sources with unusually red optical-to-near-infrared (NIR) continua. If this is to be interpreted as extinction by dust in the line of sight, then associated material might also give rise to absorption in the soft X-ray regime. This hypothesis is tested using broadband (0.1-2.4 keV) data from the ROSAT All-Sky Survey. Significant (>3 sigma confidence level) correlations between the optical (and NIR)-to-soft X-ray continuum slope and optical extinction are found in the data, consistent with absorption by material with metallicity and a range in the gas-to-dust ratio as observed in the local ISM. Under this simple model, the soft X-rays are absorbed at a level consistent with the range of extinctions (0 < A(V) < 6 mag) implied by the observed optical reddening. Excess X-ray absorption by warm (ionized) gas, (i.e., a warm absorber) is not required by the data.

X-ray computed tomography to quantify tree rooting spatial distributions

Poor root development due to constraining soil conditions could be an important factor influencing health of urban trees. Therefore, there is a need for efficient techniques to analyze the spatial distribution of tree roots. An analytical procedure for describing tree rooting patterns from X-ray computed tomography (CT) data is described and illustrated. Large irregularly shaped specimens of undisturbed sandy soil were sampled from Various positions around the base of trees using field impregnation with epoxy resin, to stabilize the cohesionless soil. Cores approximately 200 mm in diameter by 500 mm in height were extracted from these specimens. These large core samples were scanned with a medical X-ray CT device, and contiguous images of soil slices (2 mm thick) were thus produced. X-ray CT images are regarded as regularly-spaced sections through the soil although they are not actual 2D sections but matrices of voxels similar to 0.5 mm x 0.5 mm x 2 mm. The images were used to generate the equivalent of horizontal root contact maps from which three-dimensional objects, assumed to be roots, were reconstructed. The resulting connected objects were used to derive indices of the spatial organization of roots, namely: root length distribution, root length density, root growth angle distribution, root spatial distribution, and branching intensity. The successive steps of the method, from sampling to generation of indices of tree root organization, are illustrated through a case study examining rooting patterns of valuable urban trees. (C) 1999 Elsevier Science B.V. All rights reserved.

Maximum packings of K-v-K-u with triples

We construct, for all positive integers u, and v with u less than or equal to v, a decomposition of K-v - K-u (the complete graph on v vertices with a. hole of size u) into the maximum possible number of edge disjoint triangles.

Decentralized control design for nonlinear plants: a v-metric approach

In this paper, a new v-metric based approach is proposed to design decentralized controllers for multi-unit nonlinear plants that admit a set of plant decompositions in an operating space. Similar to the gap metric approach in literature, it is shown that the operating space can also be divided into several subregions based on a v-metric indicator, and each of the subregions admits the same controller structure. A comparative case study is presented to display the advantages of proposed approach over the gap metric approach. (C) 2000 Elsevier Science Ltd. All rights reserved.

The fine structure of (v, 3) directed triple systems: v equivalent to 2 (mod 3)

The fine structure of a directed triple system of index lambda is the vector (c(1), c(2),...,C-lambda), where c(i) is the number of directed triples appearing precisely i times in the system. We determine necessary and sufficient conditions for a vector to be the fine structure of a directed triple system of index 3 for upsilon = 2 (mod 3).

3D reconstruction and quantification of macropores using X-ray computed tomography and image analysis

Axial X-ray Computed tomography (CT) scanning provides a convenient means of recording the three-dimensional form of soil structure. The technique has been used for nearly two decades, but initial development has concentrated on qualitative description of images. More recently, increasing effort has been put into quantifying the geometry and topology of macropores likely to contribute to preferential now in soils. Here we describe a novel technique for tracing connected macropores in the CT scans. After object extraction, three-dimensional mathematical morphological filters are applied to quantify the reconstructed structure. These filters consist of sequences of so-called erosions and/or dilations of a 32-face structuring element to describe object distances and volumes of influence. The tracing and quantification methodologies were tested on a set of undisturbed soil cores collected in a Swiss pre-alpine meadow, where a new earthworm species (Aporrectodea nocturna) was accidentally introduced. Given the reduced number of samples analysed in this study, the results presented only illustrate the potential of the method to reconstruct and quantify macropores. Our results suggest that the introduction of the new species induced very limited chance to the soil structured for example, no difference in total macropore length or mean diameter was observed. However. in the zone colonised by, the new species. individual macropores tended to have a longer average length. be more vertical and be further apart at some depth. Overall, the approach proved well suited to the analysis of the three-dimensional architecture of macropores. It provides a framework for the analysis of complex structures, which are less satisfactorily observed and described using 2D imaging. (C) 2002 Elsevier Science B.V. All rights reserved.

Infantile spasms, dystonia, and other X-linked phenotypes caused by mutations in Aristaless related homeobox gene, ARX

Clinical data from 50 mentally retarded (MR) males in nine X-linked MR families, syndromic and non-specific, with mutations (duplication, expansion, missense, and deletion mutations) in the Aristaless related homeobox gene, ARX, were analysed. Seizures were observed with all mutations and occurred in 29 patients, including one family with a novel myoclonic epilepsy syndrome associated with the missense mutation. Seventeen patients had infantile spasms. Other phenotypes included mild to moderate MR alone, or with combinations of dystonia, ataxia or autism. These data suggest that mutations in the ARX gene are important causes of MR, often associated with diverse neurological manifestations. (C) 2002 Elsevier Science B.V. All rights reserved.

A low-temperature insulating phase at v=1.5 for 2D holes in high-mobility SiSi1-xGex heterostructures with Landau level degeneracy

Magneto-transport measurements of the 2D hole system (2DHS) in p-type Si-Si1-xGex heterostructures identify the integer quantum Hall effect (IQHE) at dominantly odd-integer filling factors v and two low-temperature insulating phases (IPs) at v = 1.5 and v less than or similar to 0.5, with re-entrance to the quantum Hall effect at v = 1. The temperature dependence, current-voltage characteristics, and tilted field and illumination responses of the IP at v = 1.5 indicate that the important physics is associated with an energy degeneracy of adjacent Landau levels of opposite spin, which provides a basis for consideration of an intrinsic, many-body origin.