bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinicopathologic and prognostic values ofapolipoprotein Dalterations in hepatocellular carcinoma
Authors: Utsunomiya Tohru , Ogawa Kazuhiko , Yoshinaga Keiji , Ohta Mitsuhiko , Yamashita Keishi , Mimori Koshi , Inoue Hiroshi , Ezaki Takahiro , Yoshikawa Yasuji , Mori Masaki
Published: March 2005

We previously identifiedapolipoprotein D(Apo D) as a novel tumor suppressor gene based on the pharmacological unmasking of epigenetic silencing. We analyzedApo Dexpression using real‐time reverse transcription‐PCR and evaluated its expression status based on the clinicopathological parameters of 70 patients with hepatocellular carcinoma (HCC). Immunohistochemical staining was also performed. We determined the methylation status ofApo Dgene promoter by methylation‐specific PCR (MSP). TheApo Dgene‐expression in tumor tissue was significantly lower than that in nontumor tissue (p= 0.011). A lowApo Dexpression significantly correlated with less‐differentiated HCC (p= 0.019). Immunohistochemical studies confirmed a decreased Apo D expression in poorly differentiated tumors. The prognosis of patients with a lowerApo Dgene‐expression was significantly worse than that in those with a higher expression (p= 0.028). TheApo Dgene‐expression was an independent prognostic factor (relative risk: 2.36,p= 0.018). An MSP assay showed a low‐level of methylation in well differentiated HCC and a high‐level of methylation in less differentiated tumors.Apo Dmay be a novel tumor suppressor gene of HCC, and its expression status may be a useful biomarker for predicting the patient outcome. © 2005 Wiley‐Liss, Inc.
Coffee consumption and the risk of primary liver cancer: Pooled analysis of two prospective studies in Japan
Authors: Shimazu Taichi , Tsubono Yoshitaka , Kuriyama Shinichi , Ohmori Kaori , Koizumi Yayoi , Nishino Yoshikazu , Shibuya Daisuke , Tsuji Ichiro
Published: March 2005

Although case‐control studies suggested that coffee consumption is associated with a decreased risk of liver cancer, no prospective cohort study has been carried out. To examine the association between coffee consumption and the risk of liver cancer, we conducted a pooled analysis of data available from 2 cohort studies in Japan. A self‐administered questionnaire about the frequency of coffee consumption and other health habits was distributed to 22,404 subjects (10,588 men and 11,816 women) in Cohort 1 and 38,703 subjects (18,869 men and 19,834 women) in Cohort 2, aged 40 years or more, with no previous history of cancer. We identified 70 and 47 cases of liver cancer among the subjects in Cohort 1 (9 years of follow‐up with 170,640 person‐years) and Cohort 2 (7 years of follow‐up with 284,948 person‐years), respectively. We used Cox proportional hazards regression analysis to estimate the relative risk (RR) and 95% confidence interval (CI) of liver cancer incidence. After adjustment for potential confounders, the pooled RR (95% CI) of drinking coffee never, occasionally and 1 or more cups/day were 1.00 (Reference), 0.71 (0.46–1.09) and 0.58 (0.36–0.96), respectively (p for trend = 0.024). In the subgroup of subjects with a history of liver disease, we found a significant inverse association between coffee consumption and the risk of liver cancer. Our findings support the hypothesis that coffee consumption decreases the risk of liver cancer. Further studies to investigate the role of coffee in prevention of liver cancer among the high‐risk population are needed. © 2005 Wiley‐Liss, Inc.
Erratum: Spectroscopic constants of H2 using Monte Carlo methods, S.A. Alexander and R.L. Coldwell, International Journal of Quantum Chemistry(2004) 100(6) 851–857
Authors: Alexander S. A. , Coldwell R. L.
Published: March 2005

The original article to which this Erratum refers was published in International Journal of Quantum Chemistry (2004) 100(6)851–857
Recognition ability and cytotoxicity of some oligosaccharidylsubstituted β‐cyclodextrins
Authors: Attioui Fatima , Al‐Omar Anouar , Leray Eric , Parrot‐Lopez Hélène , Finance Chantal , Bonaly Roger
Published: March 2005

Summary— This paper reports a chemico‐enzymatic synthesis of β‐CD derivatives. The recognition properties of these derivativeswere tested using flocculating yeast and isolated lectins. It was observed that the substitution of β‐cyclodextrins with galactose end arms induces the better recognition by a cell‐linked galactose‐specific lectin. The physicochemical effects of the β‐CD derivatives on membranes were estimated using red blood cells and the effects on the viability of yeast and human rectal tumor cells were appreciated by measuring the mitochondrial deshydrogenase activity. The substitutions of the β‐CD ring by sugar antennae decrease the negative physicochemical effects of the β‐CD, ie their, hemolytic properties. However, these substitutions induce significant modifications of the biological properties of the molecules, particularly the cytotoxicity and the growth of eukaryotic cells.
Differentiation of kidney cortex peroxisomes in fetal and newborn rats
Authors: Stefanini Stefania , Serafini Barbara , Cimini Annamaria , Sartori C.
Published: March 2005

Summary— Peroxisomal enzyme assays as well as cytochemical detection of catalase were carried out on fetal and newborn rat kidney cortex throughout the last 3 days of prenatal life and the first month of postnatal development. Concerning the patterns of peroxisomal enzymes, catalase activity, hardly detectable in the fetus, shows the strongest increment after the second week of postnatal life; β‐oxidation system and D‐amino acid oxidase increase soon after birth; urate oxidase activity, detected in fetal life, rapidly decreases after birth; dihydroxyacetone phosphate‐acyltransferase activity doubles at birth, remaining constant thereafter. Since by cytochemistry no catalase particles were detected in fetal kidneys, morphometryryc parameters were studied only postnatally. The numerical density shows only minor variations, mainly at day 3; the mean diameter remains practically unchanged between birth and day 14 but strongly increases later. The volume density pattern correlates in the early phase with the numerical density and later with the profile mean diameter. The results suggest that enzymes are asynchronously incorporated into pre‐existing peroxisomes; that this import is faster in smaller organelles than in the larger, adult ones; that catalase increases after the H202 producing oxidases; and that the abrupt rise of β‐oxidation capacity and DH‐APAT is related to the increased renal work immediately after birth.
An International Jurisprudence? The Operation of “Precedent” Across International Tribunals
Authors: Miller Nathan
Published: March 2005

Amid the proliferation of international judicial and quasi-judicial bodies, worries about the possible fragmentation of international law are increasing. Such fears, however, may be misplaced. A close examination of the jurisprudence of nine international judicial bodies, looking specifically for instances of explicit reference to one another's decisions, shows the practice to be widespread, of variable frequency and covering both procedural and substantive issues. Taken in conjunction with other scholarship about the similar treatment of important doctrines across all (or most) bodies, this study suggests that unity, not fragmentation, may emerge from the proliferation of international courts and tribunals.
Admitting and Evaluating Evidence in the International Criminal Tribunal for the Former Yugoslavia Appeals Chamber Proceedings. A Few Remarks
Authors: Lundqvist Ulf S.
Published: March 2005

This article analyses the requirements when the ICTY Appeals Chamber may overturn factual findings made by a Trial Chamber and may admit fresh evidence. The conclusion is that the Appeals Chamber should overturn factual findings only when strong reasons so indicate, since trial transcripts cannot provide the same information as did live impressions from the proceedings when the Trial Chamber reached its findings. Fresh evidence should be admitted exceptionally; otherwise the control (corrective) function of the ICTY Appeals Chamber could be weakened, endangering the division of tasks in the court organisation, the effective administration of justice and a final hearing within a reasonable time.
Chitosan‐Poly(acrylic acid): Mechanism of Complex Formation and Potential Industrial Applications
Authors: Chavasit Visith , Torres J. Antonio
Published: March 2005

The food industry is interested in polyelectrolytic coagulants of natural origin for the clarification of food beverages and the recovery of colloidal and dispersed particles from processing waste streams. This paper discusses potential industrial applications of recent findings on polymer complex formation obtained with a chitosanpoly(acrylic acid) model system. Process recommendations could be made on the basis of the ionic strength, pH, and charged group concentration of the fluid to be treated. Ionic strength does not affect the complex formation process. The amount of chitosan in the complex formed is controlled by the solution pH. The mechanism of complex formation indicates that pH measurements could be used to monitor the coagulation process.
Structural and Functional Repetition in a Marine Mussel Adhesive Protein
Authors: Filpula David R. , Lee Shwu‐Maan , Link Rebecca P. , Strausberg Susan L. , Strausberg Robert L.
Published: March 2005

The DOPA‐rich polyphenolic protein secreted by the marine mussel Mytilus edulis establishes key chemical linkages in a water‐resistant adhesive. Molecular cloning of the gene for this remarkable protein reveals its primary structure as one of the most repetitive proteins identified in the animal kingdom. Expression and purification of polyphenolic proteins from recombinant yeast have provided sufficient material to demonstrate adhesivity of these polypeptides in the laboratory. Adhesive tests reveal a water‐resistant bonding capacity of the protein that is dependent on in vitro modification of tyrosine residues to DOPA and the subsequent oxidation to quinone.
New Strategies for the Design of Catalytic Antibodies
Authors: Janda Kim D.
Published: March 2005

A new approach is advanced which is aimed at expanding the scope of antibody catalysis. It entails the design and synthesis of haptens that will elicit antibodies to catalyze acyl transfer reactions by a methodology which we term “bait and switch” catalysis. What we have done involves the placement of a point charge on the hapten in close proximity to, or in direct substitution for, a chemical functional group we wish to transform in the respective substrate. The haptenic charge should induce a complementary charge (on an amino acid residue) at the binding site. The substrate will lack this charge but will retain a similar overall structure. The monoclonal antibodies that bind these substrates now have the potential to act as general acids/bases for substrates having hydrolyzable functional groups.
Sparged Animal Cell Bioreactors: Mechanism of Cell Damage and Pluronic F‐68 Protection
Authors: Murhammer David W. , Goochee Charles F.
Published: March 2005

Pluronic F‐68 is a widely used protective agent in sparged animal cell bioreactors. In this study, the attachment‐independent Spodoptera frugiperda Sf9 insect cell line was used to explore the mechanism of this protective effect and the nature of cell damage in sparged bioreactors. First, bubble incorporation via cavitation or vortexing was induced by increasing the agitation rate in a surface‐aerated bioreactor; insect cells were rapidly killed under these conditions of the absence of polyols. Supplementing the medium with 0.2% (w/v) Pluronic F‐68, however, fully protected the cells. Next, cell growth was compared in two airlift bioreactors with similar geometry but different sparger design; one of these bioreactors consisted of a thin membrane distributor, while the other consisted of a porous stainless steel distributor. The flow rates and bubble sizes were comparable in the two bioreactors. Supplementing the medium with 0.2% (w/v) Pluronic F‐68 provided full protection to cells growing in the bioreactor with the membrane distributor but provided essentially no protection in the bioreactor with the stainless steel distributor. These results strongly suggest that cell damage can occur in the vicinity of the gas distributor. In addition, these results demonstrate that bubble size and gas flow rate are not the only important considerations of cell damage in sparged bioreactors. A model of cell death in sparged bioreactors is presented.
Kinetics of the Ferrous Iron Oxidation by Resuspended Cells of Thiobacillus ferrooxidans
Authors: Nikolov L. N. , Karamanev D. G.
Published: March 2005

Ferrous sulfate solutions with concentrations of up to the limit of solubility (70 g/L Fe2+) were oxidized by free suspended cells of Thiobacillus ferrooxidans. The bacteria used were obtained from biofilm by resuspension. The oxidation rates were up to 2.2 g of ferrous iron per liter volume of liquid media per hour, which is more than 5 times higher than the maximal oxidation rates [0.4 g/(L·h)] reported in the literature. Kinetics of the process were studied in chemostat. A simple kinetic model based on the Monod equation assuming a competitive product inhibition and substrate inhibition mechanisms was used. The model described well the experimental data with input ferrous iron concentrations between 2 and 70 g of Fe2+/L. It was determined that temperatures between 18 and 37°C have almost no effect on the oxidation rate. The same effect was observed earlier for the oxidation of ferrous iron by biofilm of the same microorganisms. A suggestion is made that these bacteria change their activity owing to alterations during fixation in a biofilm. This change is irreversible.
Application of Continuous Substrate Feeding to the ABE Fermentation: Relief of Product Inhibition Using Extraction, Perstraction, Stripping, and Pervaporation
Authors: Qureshi Nasibuddin , Maddox Ian S. , Friedl Anton
Published: March 2005

The technique of continuous substrate feeding has been applied to the batch fermentation process using freely suspended cells, for ABE (acetone–butanol–ethanol) production. To avoid the product inhibition which normally restricts ABE production to less than 20 g/L and sugar utilization to 60 g/L, a product removal technique has been integrated into the fermentation process. The techniques investigated were liquid‐liquid extraction, perstraction, gas‐stripping, and pervaporation. By using a substrate of whey permeate, the reactor productivity has been improved over that observed in a traditional batch fermentation, while equivalent lactose utilization and ABE production values of 180 g and 69 g, respectively, have been achieved in a 1‐L culture volume.
Immobilization of β‐Galactosidase on Chitosan
Authors: Carrara Carlos R. , Rubiolo Amelia C.
Published: March 2005

The β‐galactosidase immobilization on chitosan was studied. Enzymatic activity and stability were determined for the different conditions used. The best results were obtained on chitosan beads of 2.2 mm diameter where the immobilization process was carried out at 37°C with a 1% glutaraldehyde concentration and the addition of galactose. The higher activity values of the immobilized enzyme compared with those of the free β‐galactosidase could be obtained over a larger pH range and were at higher pH's and temperatures, but the best activity is only 10.7% of the free enzyme values.
Ribosome‐Inactivating Protein Production from Trichosanthes kirilowii Plant Cell Cultures
Authors: Thorup John E. , Mcdonald Karen A. , Jackman Alan P. , Bhatia Nishant , Dandekar Abhaya M.
Published: March 2005

Two ribosome‐inactivating proteins (RIPs) found in Trichosanthes kirilowii root tuber, trichosanthin (27 kDa) and TAP‐29 (29 kDa), have been reported to exhibit antiviral (including HIV‐1) and antitumor activities. Using SDS‐PAGE and Western blotting analyses, we have studied the production of intracellular and extracellular proteins from T. kirilowii callus grown on semisolid medium, callus grown in suspension, and Agrobacterium rhizogenes A4 transformed callus grown in suspension. This transformation resulted in callus rather than hairy root growth, although the growth rate of the transformed callus on hormone‐free medium was similar to that obtained for the nontransformed callus on hormone medium. Trichosanthin, identified through SDS/ PAGE and Western blotting, was detected only in root tuber and cell extracts of the transformed cell line. A 29‐kDa protein was found in intracellular extracts and extracellular solutions from all of the above samples; however, the highest yield was obtained from the broth of the agrobacterium‐transformed callus. Following ion‐exchange purification of the shake flask broth on a strong cation‐exchange column (S‐Sepharose), elution fractions containing the 29‐kDa protein showed a high degree of RIP activity, as evidenced by total inhibition of protein synthesis using an in vitro protein translation assay. The yield of the 29‐kDa protein recovered from the broth was greater than 1.0 % (w/w) of the dry weight of the callus. For comparison, the yield of TAP‐29 obtained by extraction of dried root tuber is on the order of 0.01% (w/w) of the dry weight (Lee‐Huang et al., 1991); our estimate of the 29‐kDa protein from our fresh root tuber is between 0.4% and 1% (w/w) on a dry weight basis.
Effect of Glucose Concentration on the Biomass and Phytase Productions and the Reduction of the Phytic Acid Content in Canola Meal by Aspergillus carbonarius during a Solid‐State Fermentation Process
Authors: Al‐Asheh Sameer , Duvnjak Zdravko
Published: March 2005

It was found that an increase in the glucose amount up to and including 6 g per system in the initial solid‐state culture medium resulted in an increase in the rates of the biomass growth, enzyme concentration, and phytic acid content reduction in canola meal. Inhibition of the rates of the above processes was noticed in the systems with initial glucose amounts of 12 and 24 g. The canola meal systems with 12 and 24 g of glucose had longer growth phases than those tested with lower glucose amounts, and this resulted in their higher maximum enzyme activities. Logistic law was used to model the biomass production. Models that relate the enzyme production and the phytic acid content reduction with the time of the solid‐state fermentation process for each glucose concentration are given, and they fit the experimental data produced in this work reasonably well.
Biosynthesis of Poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) from Ethanol and Pentanol by Alcaligenes eutrophus
Authors: Park Chang‐Ho , Damodaran Vijay K.
Published: March 2005

An alcohol utilizing Alcaligenes eutrophus NCIMB 12080 produced a copolymer, poly‐(hydroxybutyrate–valerate) (PHBV), in a computer‐controlled 7‐L fed‐batch fermentor when the alcohol feed contained pentanol. Pentanol as a sole carbon source was not efficient either for cell growth or for PHBV production. To achieve better cell growth and polymer production, two kinds of alcohol switch experiments were performed. The first was initial cell growth on a mixture of 50% ethanol (0.25 g/L) plus 50% pentanol (0.25 g/L) and a subsequent switch to 100% pentanol (0.5 g/L). After the alcohol switch, PHBV with 99 mol % hydroxyvalerate was produced for 7–11 h. Afterward, the hydroxybutyrate (HB) composition increased and the hydroxyvalerate (HV) mol % decreased to 63.1 mol %. The total cell mass was 5.4 g/L. The second alcohol switch was from 100% ethanol (0.5 g/L) to a mixture of 80% ethanol (0.4 g/L) plus 20% pentanol (0.1 g/L). A large amount of copolymer (47 g/L) was produced with a high polymer yield (0.64 g of polymer/g of alcohol), but the HV mol % did not exceed 13.5%. Residual biomass was 8.0 g/L.
Optimal Control of Fed‐Batch Fermentation with Autoinduction of Metabolite Production
Authors: Tartakovsky B. , Ulitzur S. , Sheintuch M.
Published: March 2005

Induction of metabolite production is a common feature of many cultures obtained by recombinant DNA technology. Synthesis of a product in these cultures is triggered by a sharp change in environmental conditions or by autoinduction in which the cells, under conditions of growth limitation, produce a species that initiates the synthesis. If product synthesis is the objective of the fermentation, then the time of induction should be optimized so that enough biomass is produced prior to induction while ample nutrient is left in the broth to sustain product synthesis after induction. In this study, recombinant luminous Escherichia coli has been used to portray an autoinductive culture in batch and fed‐batch fermentations. A model describing the cell density and substrate and inducer concentrations has been constructed, and its parameters were estimated. An optimal control strategy with three stages of the culture state (growth, inducer synthesis, and growth+product synthesis) was determined and validated experimentally by optimization of the substrate flow rate in a fed‐batch fermentation.
Development of Metabolically Engineered Saccharomyces cerevisiae Cells for the Production of Lactic Acid
Authors: Porro Danilo , Brambilla Luca , Ranzi Bianca Maria , Martegani Enzo , Alberghina Lilia
Published: March 2005

Interesting challenges from metabolically engineered Saccharomyces cerevisiae cells arise from the opportunity to obtain yeast strains useful for the production of chemical(s). In this paper, we describe the accumulation of lactic acid in the culture medium of growing, engineered yeast cells expressing a mammalian lactate dehydrogenase gene (LDH‐A). High and reproducible productions (20 g/L) and productivities (up to 11 g/L/h) of lactic acid have been obtained by modulating the physiological growth conditions. Since yeast cells are acid tolerant and survive at very low pH values, the production of lactate can be avoided. In perspective, the approaches described could be useful for the production of lactic acid, outflanking the problems related to the synthesis from bacteria cells. In fact, during industrial productions, there is an inhibitory effect on the metabolic activities of the growing bacteria (i. e., Lactobacillus spp.) caused by the acid produced and by the low pH value. Thus, strategies to prevent the lowering of pH are conventional operations. These processes allow the production of lactate(s) and require the purification of the acid from its salt. The biotechnological implications of this study are also discussed.
Membrane Chromatography—An Integrative Concept in the Downstream Processing of Proteins
Authors: Thömmes J. , Kula M.‐R.
Published: March 2005

Membrane chromatography was introduced as an integrative technology for the purification of proteins several years ago. The main feature of chromatographic separations based on membranes is the absence of pore diffusion, which is the main transport resistance in conventional column chromatography using porous particles. This is achieved by attaching the active ligands to the inner surface of the through‐pores of microfiltration membranes, where mass transport takes place mainly by convective flow, thus reducing the transport limitations from pore to film diffusion. In combination with a low pressure drop across a membrane, very high volumetric flows are possible in a membrane‐based purification step; thus, the time requirement of a complete chromatographic cycle is reduced. The method is characterized by fast processing at preserved or even increased resolution compared to standard chromatography on particulate materials. Since its introduction, many successful applications of membrane chromatography have been described. Additionally, theoretical analysis has been performed, which has significantly helped to understand present and visualize future applications of this technology. In this review, the fundamental theoretical considerations from the actual literature are described, and then the applications of membrane‐based separation processes are presented. We have attempted to demonstrate the usefulness of this new technology in the purification of many interesting proteins.
Partial and Total Cell Retention in a Filtration‐Based Homogeneous Perfusion Reactor
Authors: Banik Gautam G. , Heath Carole A.
Published: March 2005

Suspended mammalian cells can be cultivated in a variety of operational modes (pure chemostat, total cell retention, or partial cell retention) in a homogeneous perfusion bioreactor by varying the cell bleed rate. Hybridomas were grown in the reactor at a perfusion rate of 2.0 day−1 for over 10 weeks at different specific growth rates and viable cell densities achieved by varying the extent of cell retention. Cell metabolism in the reactor was found to vary with the extent of cell retention, which determined both cell density and specific growth rate. With partial cell retention, the nutrient consumption and metabolite production rates decreased with both increasing growth rate and increasing cell density. The specific and volumetric antibody production rates, however, increased dramatically with cell density (and to a lesser extent with decreasing growth rate). The specific MAb production rate was lower with total cell retention than with partial retention at the same growth rate. Since the reactor can be operated over a range of perfusion rates and extents of cell retention, the system can be used to culture cell lines with widely different productivity patterns.
Multiangle Imaging Spectroradiometer (MISR) global aerosol optical depth validation based on 2 years of coincident Aerosol Robotic Network (AERONET) observations
Authors: Kahn Ralph A. , Gaitley Barbara J. , Martonchik John V. , Diner David J. , Crean Kathleen A. , Holben Brent
Published: March 2005

Performance of the Multiangle Imaging Spectroradiometer (MISR) early postlaunch aerosol optical thickness (AOT) retrieval algorithm is assessed quantitatively over land and ocean by comparison with a 2‐year measurement record of globally distributed AERONET Sun photometers. There are sufficient coincident observations to stratify the data set by season and expected aerosol type. In addition to reporting uncertainty envelopes, we identify trends and outliers, and investigate their likely causes, with the aim of refining algorithm performance. Overall, about 2/3 of the MISR‐retrieved AOT values fall within [0.05 or 20% × AOT] of Aerosol Robotic Network (AERONET). More than a third are within [0.03 or 10% × AOT]. Correlation coefficients are highest for maritime stations (∼0.9), and lowest for dusty sites (more than ∼0.7). Retrieved spectral slopes closely match Sun photometer values for Biomass burning and continental aerosol types. Detailed comparisons suggest that adding to the algorithm climatology more absorbing spherical particles, more realistic dust analogs, and a richer selection of multimodal aerosol mixtures would reduce the remaining discrepancies for MISR retrievals over land; in addition, refining instrument low‐light‐level calibration could reduce or eliminate a small but systematic offset in maritime AOT values. On the basis of cases for which current particle models are representative, a second‐generation MISR aerosol retrieval algorithm incorporating these improvements could provide AOT accuracy unprecedented for a spaceborne technique.
Mössbauer effect study of correlation between structure and exchange-bias effect in ferromagnetic Fe∕antiferromagnetic FeSn2 bilayers
Authors: Kuncser V. E. , Stromberg F. , Acet M. , Keune W.
Published: March 2005

Antiferromagnetic (AF) FeSn2(001) epitaxial and polycrystalline layers were grown in ultrahigh vacuum under various conditions on clean InSb(001) substrates and covered by polycrystalline ferromagnetic Fe layers, forming a new system with exchange bias. Isotopically enriched Fe57- and Fe57Sn2-tracer layers were placed on either side of the Fe∕FeSn2 interface for a microscopic investigation of the spin structure and atomic interdiffusion phenomena in near-interfacial regions by Fe57 conversion electron Mössbauer spectroscopy (CEMS) at room temperature and T=10K. Several spectral components, assigned to pure bcc Fe, Sn-containing bcc Fe, AF-ordered FeSn2, and paramagnetic FeSn2 were resolved in the CEM spectra. Evidence is provided for interdiffusion across the interface. The temperature dependence of the exchange-bias field HE was measured by magnetometry. The CEMS data provide evidence for a correlation between HE at low T and chemical disorder (defects) in the FeSn2 films via the intensity of the paramagnetic line. These results support the assumption that exchange bias is related to the presence of AF domains formed via magnetic defects in the antiferromagnet. The T dependence of HE suggests interfacial exchange-coupling energies higher than the AF wall energy.
Calculation of the electrode shape for suppression of the standing wave effect in large area rectangular capacitively coupled reactors
Authors: Sansonnens L.
Published: March 2005

The electromagnetic standing wave becomes one of the main sources of plasma nonuniformity in large area capacitively coupled rf reactors. In cylindrical reactors with a central rf connection or one-dimensional linear reactors with rf connections at both extremities, Gaussian shaped electrodes can be used to suppress this standing wave. In this work, we present a two-dimensional quasiplanar circuit model and a numerical method for calculation of the electrode shape that can suppress the standing wave effect in large area rectangular reactors. It is shown that the calculated shapes are not Gaussian, and are not only a function of the reactor dimensions and excitation frequency, but are also strongly influenced by the position and number of rf connections, as will also be the case for a cylindrical reactor with a noncentral rf connection. However, when a shape has been determined for a given reactor geometry and rf excitation frequency, then it is shown that it remains independent of the plasma provided that the electromagnetic skin depth in the plasma remains large enough such that skin effects remain negligible.
Nanoscale chemical etching of near-stoichiometric lithium tantalate
Authors: Liu Xiaoyan , Terabe Kazuya , Nakamura Masaru , Takekawa Shunji , Kitamura Kenji
Published: March 2005

The chemical etching properties of ferroelectric LiTaO3 crystal in near-stoichiometric compositions were quantitatively investigated with various ratios of HF and HNO3 acid mixtures by scanning force microscopy in the nanoscale range. Along with congruent LiTaO3 crystal, the −Z surfaces of near-stoichiometric LiTaO3 crystal were etched preferentially with pure HF acid and mixtures of HF and HNO3 acids. The etching rates on the −Z surface of near-stoichiometric LiTaO3 crystal were slower than that of congruent LiTaO3 crystal. The roughness (peak to peak) of etched surfaces were about 2nm after being etched in all ratios of HF and HNO3 acids to a 70-nm etch depth. The temperature dependence of the etch rate followed the Arrhenius law. By taking advantage of the chemical preferential etching properties, precision surface structures could be fabricated on near-stoichiometric LiTaO3 crystal.
The relationship between greasy fleece weight and clean fleece weight in the South Australian Merino
Authors: Ford GH
Published: March 2005

The correlation between clean fleece weight and greasy fleece weight in South Australian strain Merino hoggets of both sexes in three widely different seasons was found to be Rams, 0.841, 0.890, 0.701 and Ewes, 0.846, 0.850 and 0.839. A covariance analysis of clean and greasy fleece weights showed no significant differences between slopes of individual sires, but significant differences between sire group means, indicating genetic variability for these two traits. It is concluded that the correlations are high enough to make selection for clean fleece weight by partial culling on the basis of greasy fleece weight, followed by scouring of midside samples of the fleece from the top sheep for greasy fleece weight, as advocated by Beattie (1956), practicable. The use of the clean fleece weight, greasy fleece weight relationship will rarely be sufficient on its own to formulate a selection plan. The conditions for the use of other aids to estimate clean fleece weight, such as the Neale squeeze machine, are discussed.
Seedling fluorescence and strain certification in subterranean clover — a reassessment
Authors: Cuthbertson EG , Briton J
Published: March 2005

The validity of the fluorescence test was queried when large numbers of aberrant fluorescents were recorded in Mt. Barker subterranean clover lines submitted for certification. The value of this screened ultra-violet light test for subterranean clover seed certification is reviewed in the light of experimental results. It is concluded that the test lacks general application but may still provide useful confirmatory evidence in specific cases.
Disease-associated mutations cause premature oligomerization of myelin proteolipid protein in the endoplasmic reticulum
Authors: Swanton Eileithyia , Holland Andrew , High Stephen , Woodman Philip
Published: March 2005

Pelizaeus–Merzbacher disease (PMD) is a dysmyelinating disease caused by mutations, deletions, or duplications of the proteolipid protein (PLP) gene. Mutant forms of PLP are retained in the endoplasmic reticulum (ER), and the resulting accumulation of mutant protein is thought to be a direct cause of oligodendrocyte cell death, which is the primary clinical feature of PMD. The molecular mechanisms underlying the toxicity of mutant PLP are however currently unknown. We report here that PMD-linked mutations of PLP are associated with the accelerated assembly of the protein into stable homooligomers that resemble mature, native PLP. Thus although WT PLP forms stable oligomers after an extended maturation period, most likely at the cell surface, mutant forms of PLP rapidly assemble into such oligomers at the ER. Using PLP mutants associated with diseases of varying severity, we show that the formation of stable oligomers correlates with the development of PMD. Based on these findings, we propose that the premature oligomerization of PLP in the ER of oligodendrocytes contributes to the pathology of PMD.
Viscosity-dependent inertial spectra of the Burgers and Korteweg–deVries–Burgers equations
Authors: Chorin Alexandre J. , Hald Ole H.
Published: March 2005

We show that the inertial range spectrum of the Burgers equation has a viscosity-dependent correction at any wave number when the viscosity is small but not zero. We also calculate the spectrum of the Korteweg–deVries–Burgers equation and show that it can be partially mapped onto the inertial spectrum of a Burgers equation with a suitable effective diffusion coefficient. These results are significant for the understanding of turbulence.
AIDS as a crisis in social reproduction
Authors: Bujra Janet
Published: March 2005

Using the conceptual framework of social reproduction as a way of reassessing the AIDS crisis in Africa, this paper finds contradictory tendencies: a devastating impact on agricultural modes of livelihood which sustain the majority and which enable workers to present themselves as cheap labour, but also a crisis for the reproduction of capital as its supply of such labour is depleted. The impact on and response to the epidemic by the state is explored as well as its reflection of marked gender and class inequalities. Conversely the impetus to certain fractions of capital which benefit from AIDS and the confrontation of the state and pharmaceutical companies by an emergent populist movement demanding the right to treatment, exposes the extent to which transformation rather than simple reproduction is in evidence.
HIV/AIDS in Africa: Links, livelihoods & legacies
Authors: Love Roy
Published: March 2005

Of the significance of HIV/AIDS at household, village and community level throughout Africa there can be no doubt. By 2002, the cumulative number of deaths from the disease in Africa had been estimated to be of the order of 19 million (calculated from Barnet & Whiteside, table 1.1 and UNAIDSa), almost 30 million Africans were estimated to be HIV positive, and by 2010 some 6 million of the then total deaths will have been in South Africa alone (Lewis, 2004). Although it is impossible to be precise, such figures considerably exceed those of around 11 million often (conservatively) estimated to have been transported during the entire period of the Atlantic slave trade (Austin, 1987). As with slavery, HIV/AIDS also primarily claims adult victims where the impact on economic production is greatest - another recent estimate is that between 1985 and 2020 over 20% of adult farm workers in the nine hardest hit African countries will have lost their lives because of AIDS (UNFAO, 2004a). While the impact is likely to be similar in many respects, two obvious differences from slavery are that the perpetrator is less easy to identify and moral judgements more readily confused, producing many examples of politically loaded policy decisions and value-laden interventions. Moreover, debates about ‘being faithful’ to one partner, possibly in marriage, and postponing teenage sex are institutional camouflage over the fact that a primary means of transfer of this disease in Africa has been through a physical activity as natural as eating and drinking, and which often involves great emotional and affectionate intimacy between two people. It can also of course be a violently imposed act by men on women and girls. In either case, there is the heightened pathos of human tragedy to which we as commentators should not lose our sensitivity and potential for empathy as a result of excessive intellectualising.
A breeding ground for terrorists? Africa & Britain's ‘war on terrorism’
Authors: Abrahamsen Rita
Published: March 2005

Prime Minister Tony Blair has famously described Africa as a‘scar on the conscience of the world’, drawing attention to the UK's moral and humanitarian obligations towards the continent. This article argues that New Labour's increasing attention to Africa is best understood in the context of an ongoing‘securitisation’ of the continent, which received added impetus following the events of September 11, 2001. Through this securitisation, interactions and dealings with Africa are gradually shifting from the category of‘development/humanitarianism’ towards a category of‘risk/fear/threat’, so that today the continent is increasingly mentioned in the context of the‘war on terrorism’. While the main responses to Africa's problems are still drawn predominantly from traditional development policies, there are subtle, yet significant changes in New Labour's policies and practices that may have significant future implications for Africa and its peoples.
The high mobility group transcription factor Sox8 is a negative regulator of osteoblast differentiation
Authors: Schmidt Katy , Schinke Thorsten , Haberland Michael , Priemel Matthias , Schilling Arndt F. , Mueldner Cordula , Rueger Johannes M. , Sock Elisabeth , Wegner Michael , Amling Michael
Published: March 2005

Bone remodeling is an important physiologic process that is required to maintain a constant bone mass. This is achieved through a balanced activity of bone-resorbing osteoclasts and bone-forming osteoblasts. In this study, we identify the high mobility group transcription factor Sox8 as a physiologic regulator of bone formation. Sox8-deficient mice display a low bone mass phenotype that is caused by a precocious osteoblast differentiation. Accordingly, primary osteoblasts derived from these mice show an accelerated mineralization ex vivo and a premature expression of osteoblast differentiation markers. To confirm the function of Sox8 as a negative regulator of osteoblast differentiation we generated transgenic mice that express Sox8 under the control of an osteoblast-specific Col1a1 promoter fragment. These mice display a severely impaired bone formation that can be explained by a strongly reduced expression of runt-related transcription factor 2, a gene encoding a transcription factor required for osteoblast differentiation. Together, these data demonstrate a novel function of Sox8, whose tightly controlled expression is critical for bone formation.
Force enhancement and relaxation rates after stretch of activated muscle fibres
Authors: Rassier Dilson E , Herzog Walter
Published: March 2005

The residual force enhancement following muscle stretch might be associated with an increase in the proportion of attached cross-bridges, as supported by stiffness measurements. In this case, it could be caused by an increase in the attachment or a decrease in the detachment rate of cross-bridges, or a combination of the two. The purpose of this study was to investigate if the stretch-induced force enhancement is related to cross-bridge attachment/detachment kinetics. Single muscle fibres dissected from the lumbrical muscle of frog were placed at a length∼20% longer than the plateau of the force–length relationship; they were maximally activated, and after full isometric force was reached, ramp stretches were imposed with amplitudes of 5 and 10% fibre length, at a speed of 40% fibre length s−1. Experiments were performed in Ringer's solution, and with the addition of 2, 5 and 10 mM of 2,3-butanedione monoxime (BDM), a drug that places cross-bridges in a pre-power-stroke state, inhibiting force production. The total force following stretch was higher than the corresponding force measured after isometric contraction at the corresponding length. This residual force enhancement was accompanied by an increased relaxation time. BDM, which decreases force production during isometric contractions, considerably increased the relative levels of force enhancement. BDM also increased relaxation times after stretch, beyond the levels observed during reference contractions in Ringer's solution, and beyond isometric control tests at the corresponding BDM concentrations. Together, these results support the idea that force enhancement is caused, at least in part, by a decrease in cross-bridge detachment rates, as manifested by the increased relaxation times following fibre stretch.
Mitochondria as integrators of information in an early-evolving animal: insights from a triterpenoid metabolite
Authors: Blackstone Neil W , Kelly Molly M , Haridas Valsala , Gutterman Jordan U
Published: March 2005

Mitochondria have the capacity to integrate environmental signals and, in animals with active stem cell populations, trigger responses in terms of growth and growth form. Colonial hydroids, which consist of feeding polyps connected by tube-like stolons, were treated with avicins, triterpenoid electrophiles whose anti-cancer properties in human cells are mediated in part by mitochondria. In treated hydroids, both oxygen uptake and mitochondrial reactive oxygen species were diminished relative to controls, similar to that observed in human cells exposed to avicins. While untreated colonies exhibit more stolon branches and connections in the centre of the colony than at the periphery, treated colonies exhibit the opposite: fewer stolon branches in the centre of the colony than at the periphery. The resulting growth form suggests an inversion of the normal pattern of colony development mediated by mitochondrial and redox-related perturbations. An as-yet-uncharacterized gradient within the colony may determine the ultimate phenotypic effect of avicin perturbation.
Dependence of Intergranular Fracture Strength of a Compact of Pressed Granules on Their Deformation Characteristics
Authors: TAKAHASHI MINORU , SUZUKI SUGURU , KOSAKAI MAMORU
Published: March 2005

Rumpf's equation for the tensile strength of a powder bed was modified to indicate the intergranular fracture strength of a bed of pressed granules. The cohesive force between compacted granules was assumed to be proportional to the corresponding contact area. This assumption was investigated by directly measuring the cohesive force between two granules of alumina. The contact area was estimated from a relation for the deformation of a granule under a contact force; two parameters, b and m, are used. The modified equation (Stgα Dg2(m+y)‐b‐1(1–ɛ/ɛ)1‐m–γpm+γ) predicts how the tensile strength (Stg) of a compact is affected by the compaction pressure (P), intergranular porosity (ɛ), and granule size (Dg).
Corrosion and Crack Growth in 33% Na2O‐67% SiO2 and 33% Li2O‐67% SiO2 Glasses
Authors: WHITE G.S. , GREENSPAN D.C. , FREIMAN S.W.
Published: March 2005

Environmentally enhanced crack growth data for 33% Na2O‐67% SiO2 and 33% Li2O‐67% SiO2 (mol%) were obtained. Corrosion data for the same glasses as determined by infrared reflection spectroscopy and atomic absorption spectroscopy were also measured. It was determined that, of the tested environments, those and only those environments which caused surface corrosion also enhanced crack growth. Crack growth curves were more complicated for these materials than for fused silica. Water‐dominated regions occurred even in environments which are known to enhance crack growth.
93Nb Fourier Transform NMR Spectroscopy of Lithium Niobate Ceramic Samples
Authors: DOUGLASS D.C. , PETERSON G.E.
Published: March 2005

Lithium niobate is a very important material for integrated optical devices. The results of a Fourier transform NMR study of nonstoichiometric ceramic samples of this material are reported here. A random distribution in nuclear quadrupole coupling constant, with an approximately Lorentzian probability density function, accounts for changes observed in the NMR spectra.
Processing‐Related Fracture Origins: IV, Elimination of Voids Produced by Organic Inclusions
Authors: LANGE F. F. , DAVIS B. I. , WRIGHT E.
Published: March 2005

Organic inclusions (e.g. lint) produce irregularly shaped voids observed at fracture origins. These voids can be eliminated from a powder compact by an organic burnout followed by isopressing at room temperature prior to sintering. This procedure was demonstrated for the case of voids produced by polystyrene spheres 4 to 100 μm in diameter

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Measurement of Carbon/Metal Ratio in a Single Grain of Nonstoichiometric Titanium Carbide
Authors: Allison Craig , Williams Wendell S.
Published: March 2005

The carbon/metal ratio, x, was measured at several points in a single grain ofTiCx 1 μm in diameter in a nickel‐bonded composite, TiC /Ni‐Mo, by electron energy loss spectroscopy. Cross sections for inner‐shell ionization of Ti and C were taken from elemental film values. A value of x=0.81 ±0.02 was obtained at the center of the grain. This result is significant for interpreting mechanical properties of the material, as they should depend on x.
Analytical Electron Microscopy of Yttria Partitioning in the Yttria‐Partially‐Stabilized Zirconia Crystal
Authors: Yagi Takeshi , Saikk Atsushi , Ishzawa Noibco , Mizltani Nowyasi , Kato Masanori
Published: March 2005

Yttria‐partiaUy‐stabilized zirconia was grown frcm the melt by the arc‐image floating zone technique and annealed at 1700'C. The yttria concentration of the crystal was measured by analytical electron microscopy. The crystal, which contained 8.6 mol% YO1. 5, consists of tetragonal and cubic phases with yttria concentrations of 3.9 and 9.7 mol% YO1.5, respectively. There is a small difference between this result and the composition expected from the ZrO2‐Y2O3 phase diagram.
Dependence of Sodium Ion Mobility upon Melt Atmosphere in GeO2 Glasses
Authors: Magruder Robert H. , Kinser Donald L. , Weeks Robert A.
Published: March 2005

Sodium ion mobilities in high‐purity GeO2 glasses were examined for glasses melted under varying oxygen partial pressure. Increased oxygen partial pressure during melting increases the sodium ion mobility for glasses melted at the same temperature. This effect is attributed to the effect of oxygen partial pressure upon intrinsic defect concentrations within the glass.