Oscillating Neutrino Mass States and Double Beta Decay

Physics of Atomic Nuclei - Neutrino oscillation is an experimentally established phenomenon by which neutrinos undergo flavor transformations periodically as they propagate large enough distances....     

High-spin states in odd-odd 168Lu

High-spin states in the odd-odd ¹⁶⁸Lu nucleus, populated in the ¹⁵⁴Sm(¹⁹F,5n) reaction at a beam energy of 96 MeV, were investigated using in-beam γ-ray spectroscopy techniques. The BC neutron crossing in the yrast band, based on πg _7/2[404]7/2⁺⊗νi _13/2[642]5/2⁺ configuration, occurs at ħω= 0.31 MeV. The two side bands, based on πh _11/2[514]9/2⁻⊗νi _13/2[642]5/2⁺ and πh _9/2[541]1/2⁻⊗νi _13/2[642]5/2⁺ configurations, show anomalous signature-splitting and signature-inversion in the first one, to occur at ħω= 0.24 MeV. A moderately delayed BC-crossing is anticipated in the second one. Received: 15 June 1998 / Revised version: 11 January 1999     

On elimination of fast variables: Applications to nonequilibrium systems

A method developed earliier in the context of Brownian motion for elimination of fast variables is applied to certain proto-type models for nonequilibrium systems. This method is compared with that of Mori et al.     

Mutually unbiased bases

After a brief review of the notion of a full set of mutually unbiased bases in an N-dimensional Hilbert space, we summarize the work of Wootters and Fields (W K Wootters and B C Fields, Ann. Phys. 191, 363 (1989)) which gives an explicit construction for such bases for the case N=p ^r , where p is a prime. Further, we show how, by exploiting certain freedom in the Wootters-Fields construction, the task of explicitly writing down such bases can be simplified for the case when p is an odd prime. In particular, we express the results entirely in terms of the character vectors of the cyclic group G of order p. We also analyse the connection between mutually unbiased bases and the representations of G.     

Maximum-likelihood approach to strain imaging using ultrasound

A maximum-likelihood (ML) strategy for strain estimation is presented as a framework for designing and evaluating bioelasticity imaging systems. Concepts from continuum mechanics, signal analysis, and acoustic scattering are combined to develop a mathematical model of the ultrasonic waveforms used to form strain images. The model includes three-dimensional (3-D) object motion described by affine transformations, Rayleigh scattering from random media, and 3-D system response functions. The likelihood function for these waveforms is derived to express the Fisher information matrix and variance bounds for displacement and strain estimation. The ML estimator is a generalized cross correlator for pre- and post-compression echo waveforms that is realized by waveform warping and filtering prior to cross correlation and peak detection. Experiments involving soft tissuelike media show the ML estimator approaches the Cramer-Rao error bound for small scaling deformations: at 5 MHz and 1.2% compression, the predicted lower bound for displacement errors is 4.4 microns and the measured standard deviation is 5.7 microns.     

Chemoenzymatic glycan-selective remodeling of a therapeutic lysosomal enzyme with high-affinity M6P-glycan ligands. Enzyme substrate specificity is the name of the game

Functionalization of therapeutic lysosomal enzymes with mannose-6-phosphate (M6P) glycan ligands represents a major strategy for enhancing the cation-independent M6P receptor (CI-MPR)-mediated cellular uptake, thus improving the overall therapeutic efficacy of the enzymes. However, the minimal high-affinity M6P-containing N-glycan ligands remain to be identified and their efficient and site-selective conjugation to therapeutic lysosomal enzymes is a challenging task. We report here the chemical synthesis of truncated M6P-glycan oxazolines and their use for enzymatic glycan remodeling of recombinant human acid α-glucosidase (rhGAA), an enzyme used for treatment of Pompe disease which is a disorder caused by a deficiency of the glycogen-degrading lysosomal enzyme. Structure–activity relationship studies identified M6P tetrasaccharide oxazoline as the minimal substrate for enzymatic transglycosylation yielding high-affinity M6P glycan ligands for the CI-MPR. Taking advantage of the substrate specificity of endoglycosidases Endo-A and Endo-F3, we found that Endo-A and Endo-F3 could efficiently deglycosylate the respective high-mannose and complex type N-glycans in rhGAA and site-selectively transfer the synthetic M6P N-glycan to the deglycosylated rhGAA without product hydrolysis. This discovery enabled a highly efficient one-pot deglycosylation/transglycosylation strategy for site-selective M6P-glycan remodeling of rhGAA to obtain a more homogeneous product. The Endo-A and Endo-F3 remodeled rhGAAs maintained full enzyme activity and demonstrated 6- and 20-fold enhanced binding affinities for CI-MPR receptor, respectively. Using an in vitro cell model system for Pompe disease, we demonstrated that the M6P-glycan remodeled rhGAA greatly outperformed the commercial rhGAA (Lumizyme) and resulted in the reversal of cellular pathology. This study provides a general and efficient method for site-selective M6P-glycan remodeling of recombinant lysosomal enzymes to achieve enhanced M6P receptor binding and cellular uptake, which could lead to improved overall therapeutic efficacy of enzyme replacement therapy.

An efficient one-pot M6P glycan remodeling of a multiply glycosylated lysosomal enzyme (Lumizyme) affords a new glycoengineered protein that shows greatly improved receptor binding, cellular uptake, and degradation of lysosomal glycogen in an in vitro model of Pompe disease.     

An investigation of the biogeochemistry of the uranium radionuclide in the munitions testing contaminated soil of Kirkcudbright, New Galloway, SW Scotland

The understanding of the bio-geochemical behavior of the uranium radionuclides in the environmental matrices is crucial for the health safety point of view. The research was carried out in munitions testing sites New Golloway (SW) of Scotland at the Dunderann firing range which is contaminated with depleted uranium and site is particularly important because it provides a controlled environment for the investigation of post depositional association of Depleted Uranium (DU) in contaminated soils. This study used the modified BCR sequential extraction method to investigates the association of DU in at the different sampling location and in a control soil and were followed by elemental analysis using inductively coupled-optical Emission spectroscopy (ICP-OES).The Certified Reference Material (CRM) were used for the validation of the concentration. The concentrations of (Bureau of Reference) BCR-extracted Uranium (U) were in the range of 4–40 (±13.2) mg kg⁻¹ for the DU-contaminated sites whilst U was barely detectable in the soil from the control site (Rebury Gun) RGW. With the exception of RGH and RGW, the values for BCR-extracted U compared well with those obtained using Aqaua-regia. The obtained result showed that the maximum Uranium deposition is at RGE and it is 20 mg kg⁻¹ before hitting the target, the 6 mg kg⁻¹ at RGH and minimum is at RGG and RGW control site.     

Synthesis of 5,6-dihydrobenz[c]acridines: a comparative study

5,6-Dihydrobenz[c]acridines were synthesized by the reaction of 1-chloro-3,4-dihydro-2-naphthaldehyde with aromatic amines under three different conditions:

a.

Thermolysis of 1-chlorovinyl-(N-aryl)imines prepared from 1-chloro-3,4-dihydro-2-naphthaldehyde.

b.

Acid catalyzed cyclization of 1-(N-aryl)amino-3,4-dihydro-2-naphthaldehydes.

c.

Thermolysis of N-arylenaminoimine hydrochlorides derived from 1-chloro-3,4-dihydro-2-naphthaldehyde in DMF medium.

All the three approaches exclusively yielded only 5,6-dihydrobenz[c]acridines and not the isomeric 7,8-dihydrobenzo[k]phenanthridines.The structures of these products have been unambiguously established by detailed NMR spectral study and by independent synthesis as well as by single crystal XRD study.     

Schwinger representation for the symmetric group: Two explicit constructions for the carrier space

We give two explicit constructions for the carrier space for the Schwinger representation of the group Sn. While the first relies on a class of functions consisting of monomials in antisymmetric variables, the second is based on the Fock space associated with the Greenberg algebra.