bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melamine ‐ formaldehyde resins II.—Thermal degradation of model compounds and resins
Authors: Anderson I. H. , Cawley M. , Steedman W. 
Published: March 2007

AbstractThe thermal degradation of a series of cured melamine‐formaldehyde resins and of two relevant model compounds has been investigated using thermogravimetry accompanied by the analysis of volatile products. Low temperature degradation reactions which occur up to ∼350°C involve the loss of water and formaldehyde, the latter arising from reversible demethylolation reactions.It is proposed that ether linkages, which model compound studies indicate would yield formaldehyde in the low temperature region, are not present to any significant degree in cured resins. Deep‐seated rupture of the polycondensate system takes place at temperatures above ∼375°C when a number of independent reactions involving both side‐chain and ring degradation give rise to products among which ammonia, hydrogen cyanide, carbon monoxide and melamine have been examined.
Computational protocol for predicting the binding affinities of zinc containing metalloprotein–ligand complexes
Authors: Jain Tarun , Jayaram B. 
Published: March 2007

AbstractZinc is one of the most important metal ions found in proteins performing specific functions associated with life processes. Coordination geometry of the zinc ion in the active site of the metalloprotein–ligand complexes poses a challenge in determining ligand binding affinities accurately in structure‐based drug design. We report here an all atom force field based computational protocol for estimating rapidly the binding affinities of zinc containing metalloprotein–ligand complexes, considering electrostatics, van der Waals, hydrophobicity, and loss in conformational entropy of protein side chains upon ligand binding along with a nonbonded approach to model the interactions of the zinc ion with all the other atoms of the complex. We examined the sensitivity of the binding affinity predictions to the choice of Lennard‐Jones parameters, partial atomic charges, and dielectric treatments adopted for system preparation and scoring. The highest correlation obtained was R2 = 0.77 (r = 0.88) for the predicted binding affinity against the experiment on a heterogenous dataset of 90 zinc containing metalloprotein–ligand complexes consisting of five unique protein targets. Model validation and parameter analysis studies underscore the robustness and predictive ability of the scoring function. The high correlation obtained suggests the potential applicability of the methodology in designing novel ligands for zinc–metalloproteins. The scoring function has been web enabled for free access at www.scfbio‐iitd.res.in/software/drugdesign/bapplz.jsp as BAPPL‐Z server (Binding Affinity Prediction of Protein–Ligand complexes containing Zinc metal ions). Proteins 2007. © 2007 Wiley‐Liss, Inc.
Anatomy of a structural pathway for activation of the catalytic domain of Src kinase Hck
Authors: Banavali Nilesh K. , Roux Benoît 
Published: March 2007

AbstractSrc kinase activity is implicated in the regulation of downstream signal transduction pathways involved in cell growth processes. Crystallographic studies indicate that activation of Hematopoietic cell kinase (Hck), a member of the Src kinase family, is accompanied structurally by a large conformational change in two specific parts of its catalytic domain: the α‐C helix and the activation loop. In the present study, molecular dynamics (MD) simulations are used to characterize the transformation pathway from the inactive to the active state. Four different conditions are considered: the presence or absence of Tyr416 phosphorylation in the activation loop, and the presence or absence of substrate ATP‐2Mg+2 in the active site. Effective free energy landscapes for local residues are determined using a combination of restrained MD simulations with a Root Mean Square Distance (RMSD) biasing potential to enforce the change followed by free MD simulations to allow relaxation from artificially enforced intermediates. A conceptual subdivision of the kinase catalytic domain into four moving parts: the flexible activation loop segment, the buried activation loop segment, the α‐C helix, and the N‐terminal end linker, leads to a concise hypothesis in which each of the moving parts are only required to be coupled to their nearest neighbor to ensure bidirectional allostery in the regulation of protein tyrosine kinases. Both Tyr416 phosphorylation and ATP‐2Mg+2 affect the local backbone torsional free energy landscapes accompanying the structural transition. When these two factors are present together, a metastable coordinated state of ATP‐2Mg+2 and the phosphorylated Tyr416 is observed that offers a possible explanation for the inhibition of protein kinase activity due to increase in Mg+2 ion concentration. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Observing‐system impact assessment using a data assimilation ensemble technique: application to the ADM–Aeolus wind profiling mission
Authors: Tan David G. H. , Andersson Erik , Fisher Michael , Isaksen Lars 
Published: March 2007

AbstractEnsembles of parallel 4D‐Var data assimilation cycles have been used to assess the impact of two observing systems: the existing network of radiosonde and wind profilers, and the future spaceborne ADM–Aeolus wind‐profiling LIDAR. We demonstrate that this new technique for impact assessment provides a practical alternative to the traditional observing system simulation experiments (OSSEs), with the particular advantage that real existing observations are assimilated exactly as in operational practice, and do not need to be simulated artificially. It is only the future observing system under test (ADM–Aeolus in our case) that is generated through simulation. Furthermore, in contrast with OSSEs, there is no need to generate an artificial reference atmosphere (‘proxy truth’ or ‘nature run’), and the problems normally associated with identical‐twin experiments are thus avoided. Our results, based on detailed simulation of the ADM–Aeolus wind‐measuring capabilities and expected data quality, show that ADM–Aeolus will provide benefits comparable to the radiosonde and wind‐profiler network, with analysis impact particularly over ocean and in the tropics. The impact is retained up to the medium range of forecast (around day 5). Our results for radiosonde and wind‐profiler impact agree qualitatively with those obtained with the well‐established observing system experiment (OSE) technique; this agreement gives some confidence in the usefulness of the ensemble‐based technique for impact assessment. Copyright © 2007 Royal Meteorological Society
Case study of ex situ remediation and conversion to a combined in situ/ex situ bioremediation approach at an oxygenated gasoline release site
Authors: Juneau Armand A. , Moyer Ellen , O'Connell Joseph E. 
Published: March 2007

AbstractIn response to an oxygenated gasoline release at a gas station site in New Hampshire, a temporary treatment system consisting of a single bedrock extraction well, a product recovery pump, an air stripper, and carbon polishing units was installed. However, this system was ineffective at removing tertiary butyl alcohol from groundwater. The subsequent remedial system design featured multiple bedrock extraction wells and an ex situ treatment system that included an air stripper, a fluidized bed bioreactor, and carbon polishing units. Treated effluent was initially discharged to surface water. Periodic evaluation of the remediation system performance led to system modifications, which included installing an additional extraction well to draw contaminated groundwater away from an on‐site water supply well, adding an iron and manganese pretreatment system, and discharge of treated effluent to an on‐site drywell. Later, the air stripper and carbon units were eliminated, and an infiltration gallery was installed to receive treated, oxygenated effluent in order to promote flushing of the smear zone and in situ bioremediation in the source area. This article discusses the design, operation, performance, and modifications to the remediation system over time, and provides recommendations for similar sites. © 2007 Wiley Periodicals, Inc.
Monitored natural attenuation forum: The case for abiotic MNA
Authors: Brown Richard A. , Wilson John T. , Ferrey Mark 
Published: March 2007

AbstractThe environmental fate and transport of chlorinated volatile organic compounds (VOCs) is controlled by the physical and chemical properties of the compound and the nature of the subsurface media through which the compound is migrating. Several processes (advection, dispersion, diffusion, biodegradation, and abiotic degradation, to name a few) result in a reduction in concentration and/or mass of contaminants in groundwater. Of these processes, biodegradation is often considered the dominant destructive attenuation mechanism for chlorinated VOCs. However, chlorinated VOCs can also degrade through abiotic processes and, in some cases, may be the primary or only destructive process occurring. © 2007 Wiley Periodicals, Inc.
An alternative efficient representation of demand‐based competitive asymmetry
Authors: DeSarbo Wayne S. , Grewal Rajdeep 
Published: March 2007

AbstractCompetitive asymmetry is defined in terms of the directional level of competition among brands/firms (i.e., unit of analysis), where the degree to which brand/firm A may compete with brand/firm B does not equal the degree to which brand/firm B competes with brand/firm A. Such a market structure phenomenon is quite commonplace in virtually every market, e.g., where there exists distinct market leaders and followers. DeSarbo, Grewal, and Wind recently (2006) proposed a new spatial methodology in SMJ to assess these competitive asymmetries based on information on consumer choice sets (i.e., a demand‐based approach). However, the approach espoused by DeSarbo et al. results in as many competitive maps as there are brands/firms in a dataset. In this research, the authors devise a distance‐based unfolding multidimensional scaling procedure for deriving joint spaces of brands/firms both as givers and takers of consumer consideration with the objective to have a more efficient representation of competitive asymmetries (i.e., one map irrespective of the number of brands/firms under study). An application is provided for an actual commercial study undertaken by a major U.S. automobile manufacturer examining the mid‐size car marketplace. The strategic implications of the results are detailed. Copyright © 2007 John Wiley & Sons, Ltd.
What is strategic management, really? Inductive derivation of a consensus definition of the field
Authors: Nag Rajiv , Hambrick Donald C. , Chen Ming‐Jer 
Published: March 2007

AbstractIt is commonly asserted that the field of strategic management is fragmented and lacks a coherent identity. This skepticism, however, is paradoxically at odds with the great success that strategic management has enjoyed. How might one explain this paradox? We seek answers to this question by relying first on a large‐scale survey of strategic management scholars from which we derive an implicit consensual definition of the field—as tacitly held by its members. We then supplement this implicit definition with an examination of the espoused definitions of the field obtained from a group of boundary‐spanning scholars. Our findings suggest that strategic management's success as a field emerges from an underlying consensus that enables it to attract multiple perspectives, while still maintaining its coherent distinctiveness. Copyright © 2007 John Wiley & Sons, Ltd.
Regulatory aspects of mycotoxins in soybean and soybean products
Authors: Nesheim Stanley , Wood Garnett E. 
Published: March 2007

AbstractMore than 50 countries have enacted or proposed regulations for the control of aflatoxins in foods and/or feeds, and at least 15 of these countries also have regulations for permitted levels of contamination by other mycotoxins. Since 1965, the U.S. Food and Drug Administration has used action levels to control aflatoxins in its compliance programs. Cooperative programs with the U.S. Department of Agriculture, state agencies, and industry also have been used to keep exposure to aflatoxins as low as practical. Soybeans support the growth of many mold species, which can produce toxins such as aflatoxins, trichothecenes (such as T‐2), and cytochalasins. The natural occurrence of these toxins in soybeans has not been a problem. Limited surveys of soybeans and soy‐based infant formulas have not revealed significant contamination. The sequence of events that leads to consideration of a mycotoxin for control programs and other regulatory activity includes determination of a toxic response, isolation and identification of the toxin, development of a sampling plan and method of analysis, and determination of incidence and levels of contamination of the susceptible commodity. The quality of soybeans can vary widely, depending on environmental, agronomic, and storage conditions. products susceptible to contamination from improper storage are subject to regulatory action on a case‐by‐case basis. The government‐industry cooperative programs have been successful in limiting human exposure to aflatoxins.
Effect of lipids on soy protein isolate solubility
Authors: Boatright W. L. , Hettiarachchy N. S. 
Published: March 2007

AbstractReduced‐lipid soy protein isolate (SPI), prepared from soy flour treated so that most of the polar lipids have been removed, exhibited an increase in protein solubility of 50% over that of the control SPI prepared from hexane‐defatted flour. Adding lipids from a commercial SPI during processing of reduced‐lipid SPI decreased SPI solubility by 46%. The 19% decreased solubility caused by the lipids (primarily phospholipids) was largely recovered by treating the protein with a reducing agent (2‐mercaptoethanol). The balance of protein insolubility, caused by the lipids, was attributed to a smaller lipid fraction (approximately 5% of the total lipids). Adding lipids during SPI processing contributed to both the formation of oxidized protein sulfhydryls, incapable of being reduced by 2‐mercaptoethanol, and to oxidative deterioration of protein as determined by protein carbonyl contents.
Lipid components that reduce protein solubility of soy protein isolates
Authors: Boatright W. L. , Hettiarachchy N. S. 
Published: March 2007

AbstractA lipid fraction from a commercial soy protein isolate (SPI), previously found to be detrimental to SPI solubility, was analyzed by size‐exclusion liquid chromatography, by high‐performance liquid chromatography (HPLC), and for chemical composition. The molecular weight of most of this material was greater than 1,100 daltons. This lipid fraction was water‐soluble yet required a strong nonpolar solvent mixture to elute it from a C18 HPLC column. The lipid material was alkaline (pH 8.7) and composed of 3.0% nitrogen, 1.6% phosphorus, 17.5% nonvolatile crude fatty acids primarily hydroxylated), 10.4% long‐chain bases, 9.9% hexuronic acid, 3.2% hexosamine, and 6.6% total sugar. The molecular weight, chemical composition, and physical characteristics (solubility characteristics, surfactant characteristics, and appearance) of this material were all similar to those reported for phytoglycolipid.
Properties of fibers produced from soy protein isolate by extrusion and wet‐spinning
Authors: Huang H. C. , Hammond E. G. , Reitmeier C. A. , Myers D. J. 
Published: March 2007

AbstractFibers were produced from soy protein isolate by both wet‐spinning and extrusion. In the wet‐spinning process, aged, alkaline protein solution was forced through a spinnerette into an acid coagulating bath. In the extrusion process, a twinscrew extruder forced a protein isolate‐water mixture through a die. The physical properties of the fibers were measured at various water activities. The fibers produced by both methods were brittle and lacked tensile strength (tenacity). The addition of glycerol reduced brittleness in extruded fibers. Zinc and calcium ions decreased the brittleness of wet‐spun fibers. The tenacity of soy fibers was significantly improved by post‐spinning treatments, including acetic anhydride, acetaldehyde, glyoxal, glutaraldehyde, a combination of glutaraldehyde and acetic anhydride, and stretching. The best extruded fibers were produced with a mixture of 45% soy protein, 15% glycerol, and 40% water, finished with a combination of glutaraldehyde and acetic anhydride and then stretched to 150% their original lengths. The best wet‐spun fibers were produced with a 19.61% soy protein suspension at pH 12.1; coagulated in a 4% hydrochloric acid solution that contained 3.3% sodium chloride, 3.3% zinc chloride, and 3.3% calcium chloride; and followed by treatment with 25% glutaraldehyde and stretching to 170% their original lengths.
Routine high‐performance liquid chromatographic determination of free 7‐ketocholesterol in some foods by two different analytical methods
Authors: Penzzi G. , Caboni M. F. , Zunin P. , Evangelisti F. , Tiscornia E. , Toschi T. Gallina , Lercker G. 
Published: March 2007

AbstractTwo methods for routine analysis of free 7‐ketocholesterol (7‐k) in foods by high‐performance liquid chromatography (HPLC) were compared. The analyzed samples were egg noodles, biscuits prepared with eggs, sweet snacks, grated Parmesan cheeses, and some ingredients utilized in the food industry (whole‐milk and whole‐egg powder). The enrichment of cholesterol oxides was carried out by solid‐phase separation of the total lipids with florisil and silica cartridges for methods A and B, respectively. The 7‐k analyses were run in normal‐phase HPLC for method A, and a reverse‐phase process was used in method B. Identification of the 7‐k peak was confirmed by gas chromatography/mass spectrometry analysis and peak purity checkvia spectral analysis with a diode array detector. The quantitation of 7‐k was carried out with an internal standard for method A and with a calibration curve for method B. The limit of quantitation (LQ) was 3 × 10−9 g/injection; the limit of detection was ten times lower than the LQ for both methods. The two methods showed good recovery (99%) and good repeatability (coefficient of variation of 3.9 and 3.7% for methods A and B, respectively). These methods allow a fast, sensitive, and reliable determination of one cholesterol oxidation product, which is present at a high concentration level in the first stages of the oxidation process.
Thermal analysis of failed‐batch palm oil by differential scanning calorimetry
Authors: Man Y. B. Che , Swe P. Z. 
Published: March 2007

AbstractThermal behavior of palm oil samples drawn from the batch crystallizers that failed during crystallization and of a control oil that was drawn from a batch that produced good crystallization were analyzed by differential scanning calorimetry under constant heating and cooling conditions. Four polymorphs—β’2, α, β’1, and β1—were observed, and their temperatures were tabulated. A rapid and sudden surge of heat demand was observed for samples from failed crystallizers. Less supercooling values were obtained from the control oil compared to the higher values for samples from failed crystallizers. In crystallization thermograms, a sharp high‐temperature exotherm (high‐T peak) and a broad low‐temperature exotherm (low‐T peak) were observed. Low‐T peaks were found almost invariably stationary at −5.1 to −5.6°C, and high‐T peaks varied depending on the saturation level of the oil. A new peak, sandwiched between the high‐T and low‐T peaks, was observed for the control oil.
Cholesterol and total fat content in farm‐raised channel catfish cultured in North Carolina
Authors: Seo Chung W. , Kowtha Bramaramba J. , Williamson Sarah 
Published: March 2007

AbstractSix batches of channel catfish, obtained from six different farms in North Carolina, were analyzed for lipid and cholesterol content. A total of 70 catfish were studied by high‐performance liquid chromatography for cholesterol estimation. The mean cholesterol value was 33.00 mg/100 g of edible fish portion. The mean fat content was 4.93 g/100 g of sample. Cholesterol content increased with fat, and fat increased with weight, whereas moisture decreased with increasing fat.
Fatty acid turnover rates in the adipose tissues of the growing chicken (Gallus domesticus)
Authors: Foglia T. A. , Cartwright A. L. , Gyurik R. J. , Philips J. G. 
Published: March 2007

AbstractThe purpose of this study was to investigate the mobility of fatty acids in adipose tissue of the chicken and to determine whether adipose tissue dynamics are altered by dietary repartitioning agents. To this end, the turnover rates of fatty acids and triglycerides were estimated in adipose tissue of growing chicks by using isopentadecanoic acid (IPDA) and elaidic acid (EA) as marker dietary fatty acids. The half‐life of IPDA in abdominal and sartorial adipose tissues of birds over 6 to 10 wk of age were 20±4 and 23±6 d, respectively. The half‐life for the remaining total carcass lipids was 23±3 d. The corresponding half‐life for EA in abdominal fat tissue of birds over 2 to 7 wk of age was 18±3 d, a half‐life not significantly different from the IPDA half‐lives. On the other hand, a thyromimetic repartitioning agent (L‐94901) fed to birds at the 2 ppm level from 2 to 7 wk of age significantly decreased the half‐life of EA in abdominal fat tissue to 6±2 d. The data suggest that fatty acids were released from a more labile adipose site and subsequently reincorporated into abdominal and sartorial tissues and that fat mobilization occurred at the same time as did adipose tissue deposition in the growing chicken.
Production of docosahexaenoic acid by marine bacteria isolated from deep sea fish
Authors: Yano Yutaka , Nakayama Akihiko , Saito Hiroaki , Ishihara Kenji 
Published: March 2007

AbstractFive bacterial strains isolated from the intestine of deep sea fish were shown to produce docosahexaenoic acid (22∶6n−3; DHA) at a level of 6.4 to 11.6% of total fatty acids when incubated in DHA‐free medium. In all of the strains examined, other polyunsaturated fatty acids were barely detectable, except for eicosapentaenoic acid (20∶5n−3). A typical strain, such as T3615, produced DHA at a concentration of about 0.8 mg/L within six days of aerobic incubation at 5°C and under atmospheric pressure. The T3615 strain, belonging to the genusVibrio, is rod‐shaped, Gram‐negative, motile and facultatively anaerobic.
Preparation and properties of cottonseed protein dispersions
Authors: Arthur Jett C. , Karon Melvin K. 
Published: March 2007

Summary

A method has been described for preparing nongelling, tacky dispersions of cottonseed protein in which trichloroacetate ion has been used to prevent gelation.

It has been shown that the properties of isolated cottonseed protein depend on (1) the method of isolating the protein (2) the concentration of protein in the dispersion, (3) the concentration of sodium hydroxide used to disperse it, and (4) the addition of trichloroacetate ion to prevent gelation.
Maternal serum corticotropin‐releasing hormone and ACTH levels as predictive markers of premature labor
Authors: Makrigiannakis A. , Semmler M. , Briese V. , Eckerle H. , Minas V. , Mylonas I. , Friese K. , Jeschke U. 
Published: March 2007

AbstractObjective: To investigate whether corticotropin‐releasing hormone (CRH) and corticotropin (ACTH) plasma concentrations in women diagnosed with preterm labor are of potential clinical value in the assessment of the risk of preterm birth. Method: Plasma samples of 79 women diagnosed with preterm labor were used in this study. Samples were divided into three groups based on the week of gestation (24th–28th, 29th–32nd, 33rd–37th). CRH and ACTH values were determined by ELISA. Result: Mean maternal peripheral plasma values of CRH and ACTH were significantly higher (p < 0.001) in women who were initially diagnosed with preterm labor and finally delivered a preterm birth, compared to women with the same diagnosis but with term birth. Conclusion: CRH and ACTH serum levels in women diagnosed with preterm labor could be used as predictors for the timing of parturition.