Isolation of adipophilin and butyrophilin from bovine milk and characterization of a cDNA encoding adipophilin

The milk fat globule membrane-associated proteins adipophilin (alias adipocyte differentiation-related protein) and butyrophilin were purified from bovine milk by reverse-phase chromatography. The nucleotide sequence of bovine adipophilin was obtained via peptide mapping and sequencing of a mammary gland cDNA clone, which comprises 1841 nucleotides and has an open reading frame of 450 amino acids. By peptide mapping, 19% of the amino acid sequence was confirmed. The obtained amino acid sequence has 87 and 80% identical residues with human and mouse adipophilin, respectively. Alignment with the proteins perilipin and TIP47 revealed two highly conserved segments, which may assemble into amphipathic alpha-helices.     

Deep-level Transient Spectroscopy of GaAs/AlGaAs Multi-Quantum Wells Grown on (100) and (311)B GaAs Substrates

Si-doped GaAs/AlGaAs multi-quantum wells structures grown by molecular beam epitaxy on (100) and (311)B GaAs substrates have been studied by using conventional deep-level transient spectroscopy (DLTS) and high-resolution Laplace DLTS techniques. One dominant electron-emitting level is observed in the quantum wells structure grown on (100) plane whose activation energy varies from 0.47 to 1.3 eV as junction electric field varies from zero field (edge of the depletion region) to 4.7 × 10⁶ V/m. Two defect states with activation energies of 0.24 and 0.80 eV are detected in the structures grown on (311)B plane. The E_c-0.24 eV trap shows that its capture cross-section is strongly temperature dependent, whilst the other two traps show no such dependence. The value of the capture barrier energy of the trap at E_c-0.24 eV is 0.39 eV.     

MIMO Systems in Random Uncorrelated,Correlated and Deterministic Radio Channels

The paper discusses the BER and spectral efficiency of different MIMO systems in random uncorrelated, correlated and deterministic environments, and more specifically uncorrelated and correlated Rayleigh and Ricean fading channels. It is known that the so-called MIMO eigenmode transmission assumes channel knowledge at the transmitter for pre-coding, whereas V-BLAST and STC do not assume the channel knowledge at the transmitter, instead they use it at the receiver for recovering the transmitted information. It is shown that for the same spectral efficiency, the BER performance of the MIMO eigenmode transmission outperforms MIMO systems like V-BLAST and STBC. In fully correlated random environment, transmitting through the largest eigenmode exploits the full transmitter-receiver array gain and diversity order, giving the maximal possible performance in terms of reducing the BER. In any of the scenarios, transmitting through the largest eigenmode gives better performance in terms of reducing the BER compared with STBC systems. Spatial multiplexing through the so-called eigensets (sets which consist of transmission modes with significant channel gain) outperforms systems like V-BLAST. In this context, adaptive modulation has been used to minimize the overall BER for a given spectral efficiency.     

Study of taste-active compounds in the water-soluble extract of mature Cheddar cheese

The chemical composition of the water-soluble extracts of mature Cheddar cheese were identified, with the emphasis on understanding the interplay of compounds contributing to the savoury taste in Cheddar. The ultra-filtered water-soluble extracts of two mature Cheddar cheeses were fractionated by gel permeation chromatography (GPC). By sensory evaluation, two taste-active GPC fractions were identified from each cheese. On the basis of chemical profiling of these fractions, aqueous model tastant mixtures were prepared and sensory omission tests carried out. Glutamic acid, organic acids and mineral salts were the main tastants, whereas the other amino acids had a limited impact on taste. The characteristic umami taste was explained by a synergistic effect of glutamic acid and salts. Matching umami taste intensities were obtained from different concentrations of glutamic acid and salts. Unmasking of a bitter or sweet taste from mixtures of sub-threshold concentrations of amino acids without glutamic acids was also observed.     

The Effect of Alkali Ions on the Incorporation of Aluminum in the Calcium Silicate Hydrate (C–S–H) Phase Resulting from Portland Cement Hydration Studied by 29Si MAS NMR

The incorporation of aluminum in the calcium–silicate–hydrate (C–S–H) phases formed by hydration of three different white Portland cements has been investigated by ²⁹Si MAS NMR. The principal difference between the three cements is their bulk Al₂O₃ contents and quantities of alkali (Na⁺ and K⁺) ions. ²⁹Si MAS NMR allows indirect detection of tetrahedral Al incorporated in the silicate chains of the C–S–H structure by the resonance from Q²(1Al) sites. Analysis of the relative ²⁹Si NMR intensities for this site, following the hydration for the three cements from 0.5 d to 30 weeks, clearly reveals that the alkali ions promote the incorporation of Al in the bridging sites of the dreierketten structure of SiO₄ tetrahedra in the C–S–H phase. The increased incorporation of Al in the C–S–H phase with increasing alkali content in the anhydrous cement is in accord with a proposed substitution mechanism where the charge deficit, obtained by the replacement of Si⁴⁺ by Al³⁺ ions in the bridging sites, is balanced by adsorption/binding of alkali ions in the interlayer region most likely in the near vicinity of the AlO₄ tetrahedra. This result is further supported by similar ²⁹Si MAS NMR experiments performed for the white Portland cements hydrated in 0.30M NaOH and NaAlO₂ solutions.     

Social identity,safety climate and self-reported accidents among construction workers

The construction industry has one of the highest frequencies of work-related accidents. We examined whether construction workers predominantly identify themselves in terms of their workgroup or in terms of the construction site. In addition, we examined the associations between social identity and safety climate, and how these constructs are associated with work-related accidents. The analyses were based on questionnaire responses from 478 construction workers from two large construction sites, and the methods involved structural equation modeling. Results showed that the workers identified themselves primarily with their workgroup, and to a lesser degree with the construction site. Social identity and safety climate were related both at the workgroup and construction site levels, meaning that social identity may be an antecedent for safety climate. The association between social identity and safety climate was stronger at the workgroup level than at the construction site level. Finally, safety climate at both levels was inversely associated with self-reported accidents, with the strongest association at the workgroup level. A focus on improving safety climate, particularly by integrating initiatives at both the workgroup and management level, may have the potential to improve safety performance and thus decrease the risk of accidents and injuries on construction sites.     

Derivation of a Monte Carlo method for modeling heterodyne detection in optical coherence tomography systems

A Monte Carlo (MC) method for modeling optical coherence tomography (OCT) measurements of a diffusely reflecting discontinuity embedded in a scattering medium is presented. For the first time to the authors' knowledge it is shown analytically that the applicability of an MC approach to this optical geometry is firmly justified, because, as we show, in the conjugate image plane the field reflected from the sample is delta-correlated from which it follows that the heterodyne signal is calculated from the intensity distribution only. This is not a trivial result because, in general, the light from the sample will have a finite spatial coherence that cannot be accounted for by MC simulation. To estimate this intensity distribution adequately we have developed a novel method for modeling a focused Gaussian beam in MC simulation. This approach is valid for a softly as well as for a strongly focused beam, and it is shown that in free space the full three-dimensional intensity distribution of a Gaussian beam is obtained. The OCT signal and the intensity distribution in a scattering medium have been obtained for several geometries with the suggested MC method; when this model and a recently published analytical model based on the extended Huygens-Fresnel principle are compared, excellent agreement is found.     

Competing risks as a multi-state model

This paper deals with the competing risks model as a special case of a multi-state model. The properties of the model are reviewed and contrasted to the so-called latent failure time approach. The relation between the competing risks model and right-censoring is discussed and regression analysis of the cumulative incidence function briefly reviewed. Two real data examples are presented and a guide to the practitioner is given.     

Increase in spinal stability obtained at levels of intra-abdominal pressure and back muscle activity realistic to work situations

In this study, sudden load was applied to the trunk and situations with alternating low levels of intra-abdominal pressure (IAP) realistic to work situations were compared. The aim was to see if IAP and the small increases in co-contraction of back muscles that follow are capable of increasing the stiffness of the lumbar spine. Nine subjects participated in ten sudden load situations during which they were asked to hold a box and conduct a percentage of maximal IAP. The hip was fixed and the load was applied horizontally on the trunk. EMG, IAP, and movement of the trunk were measured. It was found that IAP of a size likely to appear in work situations, and the concomitant increase in muscle co-activation increased the spine stiffness. This increase in stiffness decreased the movement caused by the sudden load. These results show that both abdominal- and back muscles may have an important role in stabilising the spine, and in decreasing movements caused by sudden loads likely to appear in numerous work