bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brain vesicular acetylcholine transporter in human users of drugs of abuse
Authors: Siegal Deborah , Erickson Jeffrey , Varoqui H́el̀ene , Ang Lee , Kalasinsky Kathryn S. , Peretti Frank J. , Aiken Sally S. , Wickham Dennis J. , Kish Stephen J. 
Published: April 2004

AbstractLimited animal data suggest that the dopaminergic neurotoxin methamphetamine is not toxic to brain (striatal) cholinergic neurons. However, we previously reported that activity of choline acetyltransferase (ChAT), the cholinergic marker synthetic enzyme, can be very low in brain of some human high‐dose methamphetamine users. We measured, by quantitative immunoblotting, concentrations of a second cholinergic marker, the vesicular acetylcholine transporter (VAChT), considered to be a “stable” marker of cholinergic neurons, in autopsied brain (caudate, hippocampus) of chronic users of methamphetamine and, for comparison, in brain of users of cocaine, heroin, and matched controls. Western blot analyses showed normal levels of VAChT immunoreactivity in hippocampus of all drug user groups, whereas in the dopamine‐rich caudate VAChT levels were selectively elevated (+48%) in the methamphetamine group, including the three high‐dose methamphetamine users who had severely reduced ChAT activity. To the extent that cholinergic neuron integrity can be inferred from VAChT concentration, our data suggest that methamphetamine does not cause loss of striatal cholinergic neurons, but might damage/downregulate brain ChAT in some high‐dose users. However, the finding of increased VAChT levels suggests that brain VAChT concentration might be subject to up‐ and downregulation as part of a compensatory process to maintain homeostasis of neuronal cholinergic activity. This possibility should be taken into account when utilizing VAChT as a neuroimaging outcome marker for cholinergic neuron number in human studies. Synapse 52:223–232, 2004. Published 2004 Wiley‐Liss, Inc.
Management options for the Blackwater herring, a local spring-spawning stock in the Thames Estuary
Authors: Roel Beatriz A. , O'Brien Carl M. , Basson Marinelle 
Published: April 2004

Abstract
Herring caught in the Thames Estuary sustain a small local commercial fishery (peak catch of 606 t during the 1972–1973 fishing season). Loss of local consumers' interest in the herring product has resulted in a gradual decline in catches and fishing effort for the stock. The stock is assessed using an age-structured model that relies on the information provided by a scientific trawl survey, and management advice is provided before the fishing season starts in October. Given its current low economic value, managers have requested evaluation of options for multi-annual Total Allowable Catches (TACs) in an attempt to reduce the frequency (and costs) of assessment and associated management advice. A tentative relationship between sea surface temperature and recruitment is used to predict the impact of increasing sea temperatures on future recruitment in the context of global warming. Hypotheses of auto-correlation and of an environmental effect on recruitment, together with trends in weight-at-age and the overestimation of spawning-stock biomass, form the basis for sensitivity tests of the management options considered. Implementation of a 3-year fixed TAC with 40% constraint in TAC variability and a slight reduction in target F would seem appropriate for the stock, given that it is within safe biological limits and compares well in terms of yield and risk with the current approach of annual TAC revision.
THE FIFTY YEARS' RIFT: INTELLECTUAL HISTORY AND INTERNATIONAL RELATIONS
Authors: ARMITAGE DAVID 
Published: April 2004

Georg Cavallar, The Rights of Strangers: Theories of International Hospitality, the Global Community, and Political Justice since Vitoria (Aldershot: Ashgate, 2002)Jonathan Haslam, No Virtue Like Necessity: Realist Thought in International Relations since Machiavelli (New Haven, CT: Yale University Press, 2002)Edward Keene, Beyond the Anarchical Society: Grotius, Colonialism and Order in World Politics (Cambridge: Cambridge University Press, 2002)
THE DIALECTIC OF LIBERTY: LAW AND RELIGION IN ANGLO-AMERICAN CULTURE
Authors: FERGUSON ROBERT A. 
Published: April 2004

The separation of church and state disguised the coordination of two very different conceptions of liberty at work in Revolutionary America, one with a religious basis in radical Protestant thought and the other with a legal basis in the secular Enlightenment. The essay combines the disciplines of law, literature, and intellectual history to investigate these contrasting formulations and their changing relationship. Cross-cultural analysis of the language of protest in both England and America gives the investigation a crucial focus. It also explains a larger movement from direct influence to refraction in Anglo-American relations.The interdisciplinary approach is critical to understanding how the same language came to mean different things. Exegesis of the common law tradition in England and close rhetorical analysis of pulpit oratory and legal pamphleteering in Revolutionary America reveal a striking shift in the meaning of liberty as legal explanation trumped religious protest in the process of national formations. Properly understood, the paradoxical role of the American lawyer was to cap revolutionary impulses through the manipulation of the language of a bible culture. Legal positivism replaced natural law as a ruling impulse in the definition of rights, and a republic based on the right of revolution became a nation state where the test of membership would be loyalty. The long-term result has been that the citizen faces a permanent and often puzzling dichotomy best understood in dialectical terms. National identity, while secular, responds to providential invocation in the American republic of laws, and protest finds its most potent voice in religious expression.
UpGene: Application of a Web‐Based DNA Codon Optimization Algorithm
Authors: Gao Wentao , Rzewski Alexis , Sun Huijie , Robbins Paul D. , Gambotto Andrea 
Published: April 2004

AbstractAlthough DNA codon optimization is a standard molecular biology strategy to overcome poor gene expression, to date no public software exists to facilitate this process. Among the uses of codon optimization, human immunodeficiency virus (HIV) vaccine development represents one of the most difficult challenges. A key obstacle to an effective DNA‐based vaccine is the low‐level expression of HIV genes in mammalian cells, which is due primarily to the instability of HIV mRNAs resulting from AU‐rich elements and rare codon usage. In this report we describe the development of a DNA optimization algorithm integrated with a PCR primer design program to redesign specific coding sequences for maximal gene expression. Using this algorithm combination, together with PCR‐based gene assembly, we have successfully optimized gene sequences for simian immunodeficiency virus (SIV) strain mac239 structural antigenic proteins gag and env, resulting in high‐level gene expression in eukaryotic cells. Our findings demonstrate that our user‐friendly algorithm is a valuable tool for DNA‐based HIV vaccine development. Moreover, it can be used to optimize any other genes of interest and is freely available online at http://www.vectorcore.pitt.edu/upgene.html.
On‐Line Sterilization of Cheese Whey Using Ultraviolet Radiation
Authors: Mahmoud N. S. , Ghaly A. E. 
Published: April 2004

AbstractThe effectiveness of ultraviolet radiation for on‐line sterilization of cheese whey was investigated. The effects of flow rate and residence time on the performance of three UV reactors having different gap sizes (18, 13, and 6 mm) were studied. Six flow rates and six residence times were tested with the three UV reactors. The cheese whey used in this study had a very high turbidity (4317 NTU), very poor transmittance in the UV radiation germicidal range (∼0%), and high percentage of large solid particles (∼20% > 100 μm). Although the cheese whey physical characteristics showed low probability of sterilization using UV radiation, the study showed that UV radiation can be used on‐line to sterilize cheese whey if the proper reactor gap size and the appropriate residence time are used. There were combined effects of the flow rate and gap size. The cell removal efficiency increased with increases in residence time and decreases in the UV reactor gap size. Removal efficiency of 100% was not achieved in this study with the first UV reactor (18‐mm gap size), whereas 100% removal efficiency was achieved with the second (13‐mm gap size) and third (6‐mm gap size) UV reactors at residence times of 2.0 and 0.5 h, respectively. The microbial decay rates achieved in this study were 4.94, 7.62, and 20.9 h−1 using the first, second, and third UV reactor, respectively. Residence times of 3.3, 2.1, and 0.8 h would be required to completely destruct a microbial population of 5.95 × 106 cells/mL using the first, second, and third UV reactors, respectively. Although cheese whey sterilization using UV radiation seems to be a good alternative to pasteurization, increases in cheese whey temperature resulted in lamp fouling. If online sterilization is to be used, the fouling problem should be investigated and a maintenance scheme for the UV reactor should be developed.
Hollow‐Fiber Enzyme Reactor Operating under Nonisothermal Conditions
Authors: Diano Nadia , Grano Valentina , Rossi Sergio , Bencivenga Umberto , Portaccio Marianna , Amato Umberto , Carfora Francesca , Lepore Maria , Gaeta Francesco Saverio , Mita Damiano Gustavo 
Published: April 2004

AbstractA hollow‐fiber enzyme reactor, operating under isothermal and nonisothermal conditions, was built employing a polypropylene hollow fiber onto which β‐galactosidase was immobilized. Hexamethylenediamine and glutaraldehyde were used as spacer and coupling agent, respectively. Glucose production was studied as a function of temperature, substrate concentration, and size of the transmembrane temperature gradient. The actual average temperature differences across the polypropylene fiber, to which reference was done to evaluate the effect of the nonisothermal conditions, were calculated by means of a mathematical approach, which made it possible to know, using computer simulation, the radial and axial temperature profiles inside the bioreactor and across the membrane. Percent activity increases, proportional to the size of the temperature gradients, were found when the enzyme activities under nonisothermal conditions were compared to those measured under comparable isothermal conditions. Percent reductions of the production times, proportional to the applied temperature gradients, were also calculated. The advantage of employing nonisothermal bioreactors in biotechnological industrial process was discussed.
Recovery of Lactoferrin and Lactoperoxidase from Sweet Whey Using Colloidal Gas Aphrons (CGAs) Generated from an Anionic Surfactant, AOT
Authors: Fuda Elisabeth , Jauregi Paula , Pyle D. L. 
Published: April 2004

AbstractThe recovery of lactoferrin and lactoperoxidase from sweet whey was studied using colloidal gas aphrons (CGAs), which are surfactant‐stabilized microbubbles (10–100 μm). CGAs are generated by intense stirring (8000 rpm for 10 min) of the anionic surfactant AOT (sodium bis‐2‐ethylhexyl sulfosuccinate). A volume of CGAs (10–30 mL) is mixed with a given volume of whey (1–10 mL), and the mixture is allowed to separate into two phases: the aphron (top) phase and the liquid (bottom) phase. Each of the phases is analyzed by SDS‐PAGE and surfactant colorimetric assay. A statistical experimental design has been developed to assess the effect of different process parameters including pH, ionic strength, the concentration of surfactant in the CGAs generating solution, the volume of CGAs and the volume of whey on separation efficiency. As expected pH, ionic strength and the volume of whey (i.e. the amount of total protein in the starting material) are the main factors influencing the partitioning of the Lf·Lp fraction into the aphron phase. Moreover, it has been demonstrated that best separation performance was achieved at pH = 4 and ionic strength = 0.1 mol/L i.e., with conditions favoring electrostatic interactions between target proteins and CGAs (recovery was 90% and the concentration of lactoferrin and lactoperoxidase in the aphron phase was 25 times higher than that in the liquid phase), whereas conditions favoring hydrophobic interactions (pH close to pI and high ionic strength) led to lower performance. However, under these conditions, as confirmed by zeta potential measurements, the adsorption of both target proteins and contaminant proteins is favored. Thus, low selectivity is achieved at all of the studied conditions. These results confirm the initial hypothesis that CGAs act as ion exchangers and that the selectivity of the process can be manipulated by changing main operating parameters such as type of surfactant, pH and ionic strength.
Assessment of the Two Helicobacter pylori α‐1,3‐Fucosyltransferase Ortholog Genes for the Large‐Scale Synthesis of LewisX Human Milk Oligosaccharides by Metabolically Engineered Escherichia coli
Authors: Dumon Claire , Samain Eric , Priem Bernard 
Published: April 2004

AbstractWe previously described a bacterial fermentation process for the in vivo conversion of lactose into fucosylated derivatives of lacto‐ N‐neotetraose Gal(β1–4)GlcNAc(β1–3)Gal(β1–4)Glc (LNnT). The major product obtained was lacto‐ N‐neofucopentaose‐V Gal(β1–4)GlcNAc(β1–3)Gal(β1–4)[Fuc(α1–3)]Glc, carrying fucose on the glucosyl residue of LNnT. Only a small amount of oligosaccharides fucosylated on N‐acetylglucosaminyl residues and thus carrying the LewisX group (LeX) was also produced. We report here a fermentation process for the large‐scale production of LeX oligosaccharides. The two fucosyltransferase genes futA and futB of Helicobacter pylori (strain 26695) were compared in order to optimize fucosylation in vivo. futA was found to provide the best activity on the LNnT acceptor, whereas futB expressed a better LeX activity in vitro. Both genes were expressed to produce oligosaccharides in engineered Escherichia coli ( E. coli) cells. The fucosylation pattern of the recombinant oligosaccharides was closely correlated with the specificity observed in vitro, FutB favoring the formation of LeX carrying oligosaccharides. Lacto‐ N‐neodifucohexaose‐II Gal(β1–4)[Fuc(α1–3)]GlcNAc(β1–3)Gal(β1–4)[Fuc(α1–3)]Glc represented 70% of the total oligosaccharide amount of futA‐on‐driven fermentation and was produced at a concentration of 1.7 g/L. Fermentation driven by futBled to equal amounts of both lacto‐ N‐neofucopentaose‐V and lacto‐ N‐neofucopentaose‐II Gal(β1–4)[Fuc(α1–3)]GlcNAc(β1–3)Gal(β1–4)Glc, produced at 280 and 260 mg/L, respectively. Unexpectedly, a noticeable proportion (0.5 g/L) of the human milk oligosaccharide 3‐fucosyllactose Gal(β1–4)[Fuc(α1–3)]Glc was produced in futA‐on‐driven fermentation, underlining the activity of fucosyltransferase FutA in E. coli and leading to a reassessment of its activity on lactose. All oligosaccharides produced by the products of both fut genes were natural compounds of human milk.
Hyperosmotic Stress in Murine Hybridoma Cells: Effects on Antibody Transcription, Translation, Posttranslational Processing, and the Cell Cycle
Authors: Sun Zhe , Zhou Rui , Liang Shuyan , McNeeley Kathleen M. , Sharfstein Susan T. 
Published: April 2004

AbstractMechanisms for increased antibody production in batch cultures of murine hybridoma cells in response to hyperosmotic stress were investigated. The rates of immunoglobulin transcription and protein translation and posttranslational processing were determined in control and hyperosmotic cultures. Changes in immunoglobulin transcription played a minor role in the increase in antibody production in response to hyperosmotic stress. In contrast, protein translation increased substantially in response to osmotic stress. However, the antibody translation rate remained relatively constant after correcting for the overall increase in protein translation. Cell size and intracellular antibody pool also increased in response to hyperosmolarity. The intracellular antibody pool increased proportionately with the increase in cell size, indicating that hyperosmotic cultures do not selectively increase their intracellular antibody population. Changes in cell cycle distribution in response to osmotic stress and the relationship between the cell cycle and antibody production were also evaluated. Hyperosmotic stress altered the cell cycle distribution, increasing the fraction of the cells in S‐phase. However, this change was uncorrelated with the increase in antibody production rate. Immunoglobulin degradation was relatively low (∼15%) and remained largely unchanged in response to hyperosmotic stress. There was no apparent increase in immunoglobulin stability as a result of osmotic stress. Antibody secretion rates increased approximately 50% in response to osmotic stress, with a commensurate increase in the antibody assembly rate. The rate of transit through the entire posttranslational processing apparatus increased, particularly for immunoglobulin light chains. The levels of endoplasmic reticulum chaperones did not increase as a fraction of the total cellular protein but were increased on a per cell basis as the result of an increase in total cellular protein. A difference in the interactions between the immunoglobulin heavy chains and BiP/GRP78 was observed in response to hyperosmotic conditions. This change in interaction may be correlated with the decrease in transit time through the posttranslational pathways. The increase in the posttranslational processing rate appears to be commensurate with the increase in antibody production in response to hyperosmotic stress.
Protein Partitioning in Aqueous Two‐Phase Systems Composed of a pH‐Responsive Copolymer and Poly(ethylene glycol)
Authors: Waziri Saidu M. , Abu‐Sharkh Basel F. , Ali Sk Asrof 
Published: April 2004

AbstractThe effect of pH and salt concentration on the partitioning behavior of bovine serum albumin (BSA) and cytochrome c in an aqueous two‐phase polymer system containing a novel pH‐responsive copolymer that mimics the structure of proteins and poly(ethylene glycol) (PEG) was investigated. The two‐phase system has low viscosity. Depending on pH and salt concentration, the cytochrome c was found to preferentially partition into the pH‐responsive copolymer‐rich (bottom) phase under all conditions of pH and salt concentrations considered in the study. This was caused by the attraction between the positively charged protein and negatively charged copolymer. BSA partitioning showed a more complex behavior and partitioned either to the PEG phase or copolymer phase depending on the pH and ionic strength. Extremely high partitioning levels (partition coefficient of 0.004) and very high separation ratios of the two proteins (up to 48) were recorded in the new systems. This was attributed to strong electrostatic interactions between the proteins and the charged copolymer.
Modeling the Kinetics of the Pectin Methylesterase Catalyzed De‐esterfication of Pectin in Frozen Systems
Authors: Terefe Netsanet Shiferaw , Nhan Minh Tri , Vallejo David , Van Loey Ann , Hendrickx Marc 
Published: April 2004

AbstractThe applicability of the William, Landel, and Ferry (WLF) equation with a modification to take into account the effect of melt‐dilution and an empirical log‐logistic equation were evaluated to model the kinetics of diffusion‐controlled reactions in frozen systems. Kinetic data for the pectin methylesterase catalyzed hydrolysis of pectin in four model systems with different glass transition temperatures: sucrose, maltodextrin (DE = 16.5–19.5), carboxymethylcellulose (CMC) and fructose in a temperature range of –24 to 0 °C were used. The modified WLF equation was evaluated with a concentration‐dependent glass transition temperature ( Tg) as well as the glass transition temperature of the maximally freeze‐concentrated matrix ( Tg′) as reference temperatures. The equation with temperature‐dependent Tg described the reaction kinetics reasonably well in all the model systems studied. However the kinetics was better described by a linear relationship between log( V0/ V0ref) and ( T – Tref) in all cases except CMC. The log‐logistic equation also described the kinetics reasonably well. The effect of melt‐dilution on reactant concentration was found to be minimal in all cases.
Real‐Time Intracellular Transport of Gene Nanocarriers Studied by Multiple Particle Tracking
Authors: Suh Junghae , Wirtz Denis , Hanes Justin 
Published: April 2004

AbstractWe used real‐time multiple particle tracking to quantitatively characterize the type and rates of transport of gene nanocarriers within live cells. The heterogeneous cytoplasmic transport of polyethylenimine (PEI)/DNA gene carriers was quantified by tracking their mean‐square displacements over time and classified into active and nonactive transport populations on the basis of their effective diffusivities versus time. Nonactive gene carriers frequently displayed hop‐diffusion trajectories, suggesting a porous cytoplasmic network of flexible biopolymers or sequential attachment and detachment events. Microtubule‐dependent active transport of gene carriers resulted in an effective diffusivity 30‐fold greater than that of nonactive carriers (at a time scale of 3 s). Compared to nonactive carriers in control cells with intact microtubules, microtubule depolymerization enhanced short‐range motion of gene carriers but resulted in similar long‐range transport. Multiple particle tracking characterizes gene carrier transport in complex biological environments and, therefore, may be a useful tool in quantifying rate‐limiting steps in gene delivery within cells and other biological media.
Separation of Protein Charge Variants by Ultrafiltration
Authors: Ebersold Mareia Frost , Zydney Andrew L. 
Published: April 2004

AbstractThe removal of product variants that form during downstream processing remains a challenge in the purification of recombinant therapeutic proteins. We examined the feasibility of separating variants with slightly different net charge using high‐performance membrane ultrafiltration. A myoglobin variant was formed by reaction of the lysine ϵ‐amino group with succinic anhydride. Sieving data were obtained over a range of solution conditions using commercial polyethersulfone ultrafiltration membranes. Maximum selectivity of about 7‐fold was obtained at very low conductivity due to the strong electrostatic repulsion of the more negatively charged variant. Protein separations were performed by diafiltration. A two‐stage process generated solutions of the normal myoglobin (in the permeate) and the charge variant (in the retentate), both at greater than 9‐fold purification and 90% yield. These results provide the first demonstration that membrane systems can be used to separate proteins that differ by only a single charged amino acid residue.