bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene delivery to airway epithelial cells in vivo: a direct comparison of apical and basolateral transduction strategies using pseudotyped lentivirus vectors
Authors: Kremer Karlea L. , Dunning Kylie R. , Parsons David W. , Anson Donald S.
Published: March 2007

Lentivirus vectors are being investigated as gene delivery vehicles for cystic fibrosis airway gene therapy. Vesicular stomatitis virus G glycoprotein (VSV‐G)‐pseudotyped vectors transduce airway epithelia via receptors that are located predominantly on the basolateral surface of the airway epithelium. Effective transduction with VSV‐G‐pseudotyped vectors requires the use of a pre‐treatment that disrupts epithelial tight junctions, allowing access to these basolateral receptors. In contrast, it has been reported that apically targeted lentiviral vectors allow efficient gene transfer in the absence of any pre‐treatment. In a direct comparison of transduction by a VSV‐G‐pseudotyped vector, in combination with a pre‐treatment with lysophosphatidylcholine (LPC), and the same vector pseudotyped with the apically targeted baculovirus GP64 envelope (without any pre‐treatment), the GP64 vector was found to be significantly less efficient. However, when a pre‐treatment with LPC was used the level of transduction with the GP64‐pseudotyped lentiviral vector was not significantly different to that resulting from the VSV‐G‐pseudotyped vector. The cell types transduced with each vector were essentially the same, with the majority of cells transduced being respiratory (ciliated cells). However, unlike the VSV‐G‐pseudotyped vector, which results in persisting gene expression, transduction with the GP64‐pseudotyped vector resulted in gene expression that declined to undetectable levels over six months, whether or not an LPC pre‐treatment was used. Copyright © 2007 John Wiley & Sons, Ltd.
Diffusion and perfusion magnetic resonance imaging of the evolution of hypoxic ischemic encephalopathy in the neonatal rabbit
Authors: D'Arceuil Helen E. , de Crespigny Alex J. , Röther Joachim , Seri Shigemi , Moseley Michael E. , Stevenson David K. , Rhine William
Published: March 2007

Hypoxic‐ischemic encephalopathy (HIE) can result from neonatal asphyxia, the pathophysiology of which is poorly understood. We studied the acute evolution of this disease, using magnetic resonance imaging in an established animal model. HIE was induced in neonatal rabbits by a combination of common carotid artery (CCA) ligation and hypoxia. Serial diffusion and perfusion‐weighted magnetic resonance images were acquired before, during, and after the hypoxic interval. Focal areas of decreased apparent diffusion coefficient (ADC) were detected initially in the cortex ipsilateral to CCA ligation within 62 ± 48 min from the onset of hypoxia. Subsequently, these areas of decreased ADC spread to the subcortical white matter, basal ganglia (ipsilateral side), and then to the contralateral side. Corresponding perfusion‐weighted images showed relative cerebral blood volume deficits which closely matched those regions of ADC change. Our results show that MRI diffusion and perfusion‐weighted imaging can detect acute cell swelling post‐hypoxia in this HIE model.
1H MRS in acute traumatic brain injury
Authors: Ross Brian D. , Ernst Thomas , Kreis Roland , Haseler Luke J. , Bayer Stefan , Danielsen Else , Blüml Stefan , Shonk Truda , Mandigo Jennifer C. , Caton William , Clark Christopher , Jensen Steen W. , Lehman Norman L. , Arcinue Edgardo , Pudenz Robert , Shelden C. Hunter
Published: March 2007

The objective of this study was to demonstrate 1H MR spectroscopy (MRS) changes in cerebral metabolites after acute head trauma. Twenty‐five patients (12 children, 13 adults) were examined with quantitative 1H MRS after closed head injury. Clinical grade (Glasgow Coma Scale [GCS]) and outcome (Rancho Los Amigos Medical Center Outcome Score [ROS]) were correlated with quantitative neurochemical findings. N‐acetylas‐partate (NAA), a neuronal and axonal marker, was reduced (P < .03−.001). In children, a reduced NAA/creatine plus phosphocreatine (Cr) level and the presence of detectable lipid/lactate predicted bad outcome (sensitivity, 89%; specificity, 89%). The first MRS examination of all patients correlated with ROS versus NAA (r = .65, P < .0001). Although most patients showed MRS abnormalities, striking heterogeneity of 1H MRS characterized the individual patients. 1H MRS identifies multiple patterns of diffuse brain injury after blunt head trauma. There was a strong correlation between MRS and outcome. Future prospective studies will be needed to determine the clinical usefulness of MRS in predicting outcome from closed head injury.
Neural network for the estimation of UV erythemal irradiance using solar broadband irradiance
Authors: Alados I. , Gomera M. A. , Foyo‐Moreno I. , Alados‐Arboledas L.
Published: March 2007

In recent years there has been a substantial increase in attempts to model radiative flux of ultraviolet radiation, UV. In this paper we present the development of an artificial neural network (ANN) model that can be used to estimate solar UV erythemal irradiance, UVER, based on optical air mass, ozone columnar content and broadband solar irradiance. The study was developed at seven stations in the Iberian Peninsula using data recorded at A Coruña, Málaga, Murcia and Santander, during 2000–2003; at Madrid in the period 2000–2002; at Valencia in 2000, 2001 and 2003; and at Zaragoza, from 2001 to 2003. The UVER observations are recorded as half‐hour average values. The measurements were performed in the framework of the Spanish UV‐B radiometric network operated and maintained by the Spanish Meteorological Institute. In order to train and validate the Multi‐layer Perceptron neural networks, independent subsets of data were extracted from the complete database at each station. The networks developed at each place when applied to an independent data set recorded at the same location provide estimates with mean bias deviation less than 1% and root mean square deviation below 17% for all the sites. The generalization network developed using data registered at A Coruña, Madrid, Murcia and Zaragoza provides estimates at all the locations with RMSD below 19%. According to these results, the use of solar broadband irradiances for the estimation of ultraviolet erythemal irradiance provides a tool that can solve the difficulties associated to the retrieval of appropriate information on the cloud field by human observers. In this sense, the proposed method seems appropriate to use the widespread networks of solar broadband irradiance to obtain ultraviolet erythemal irradiance data sets in places where this radiative flux is not measured or to extend back in time the existing data sets. Copyright © 2007 Royal Meteorological Society
Assembly of Polyelectrolytes on CNTs by Van der Waals Interactions and Fabrication of LBL Polyelectrolyte/CNT Composites
Authors: Moya Sergio E. , Ilie Adelina , Bendall James S. , Hernandez‐Lopez Jose L. , Ruiz‐García Jaime , Huck Wilhelm T. S.
Published: March 2007

We have successfully coated CNTs with either positively or negatively charged polyelectrolytes employing Van der Waals interactions between nanotubes and polyelectrolyte molecules, without any previous chemical modification of the nanotubes walls. Polymer adsorption of polyelectrolytes was performed in an ethanolic solution, followed by redispersion in water. The surface coating was verified with ζ‐potential measurements and SEM. A sequential assembly of polyelectrolyte layers on top of the polyelectrolyte modified nanotubes has been achieved from a water solution following the layer‐by‐layer technique. The assembly of polyelectrolytes from water on CNTs deposited on a surface has also been shown with QCM‐D. Then, polyelectrolyte coated CNTs have been used as positive and negative blocks in the templating of layer‐by‐layer films.

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Description of an advanced practice nursing consultative model to reduce restrictive siderail use in nursing homes
Authors: Wagner Laura M. , Capezuti Elizabeth , Brush Barbara , Boltz Marie , Renz Susan , Talerico Karen A.
Published: March 2007

Researchers have demonstrated that the use of physical restraints in nursing homes can be reduced, particularly where advanced practice nurses (APNs) are utilized. We examined the link between APN practice, siderail reduction, and the costs of siderail alternatives in 273 residents in four Philadelphia nursing homes. The majority of participants were cognitively and physically impaired with multiple co‐morbidities. APNs recommended a total of 1,275 siderail‐alternative interventions aimed at reducing fall risk. The median cost of siderail alternatives to prevent falls per resident was $135. Residents with a fall history experienced a significantly higher cost of recommendation compared to non‐fallers. Findings suggest that an APN consultation model can effectively be implemented through comprehensive, individualized assessment without incurring substantial costs to the nursing home. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30: 131–140, 2007
Structural causes of the dyeing variations of nylon yarns subjected to steam heat
Authors: Warwicker J. O.
Published: March 2007

Nylon 6 and nylon 6.6 yarns were subjected to wet heat in a relaxed state and the subsequent rate of dyeing of these yarns with Durazol Blue 2R was then studied. The rate of dyeing progressively increased as the temperature of steaming increased. For nylon 6 this increase in rate of dyeing was almost eightfold in heating up to 140°C compared with that of unheated samples; for nylon 6.6 the increase was threefold after heating in steam at 150°C. It was confirmed that Fick's law is still valid for describing the dyeing process with nylon 6.6 but not with nylon 6. Measurements of density, birefringence, X‐ray orientation and degree of lateral order by an X‐ray method show that these are all increased by the steam treatments. There is little change in the moisture regain and amine end‐group content. An explanation of these observations is advanced in terms of a morphology that allows an increase in the size, shape or quantity of voids on heating the polyamides in steam.
Application of the modified avrami equations to polymer crystallisation kinetics
Authors: Hay J. N.
Published: March 2007

Explanations of the deviations of polymer crystallisation isotherms from Avrami equations are considered in the light of the assumptions inherent in the derivation of the equations and analysis of the crystallisation isotherms; these explanations are rejected. Modified equations which allow for the presence of several crystallisation mechanisms and recrystallisation are considered to be a more satisfactory physical model of spherulitic crystallisation from the melt. While they describe the crystallisation isotherms more accurately than a single Avrami process, non‐random deviations which cannot be satisfactorily explained still exist. Further modifications to include changing nucleation characteristics, induction periods, etc., do not improve the fit of these modified equations.
Melamine ‐ formaldehyde resins II.—Thermal degradation of model compounds and resins
Authors: Anderson I. H. , Cawley M. , Steedman W.
Published: March 2007

The 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

Zinc 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

Src 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

Ensembles 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

In 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

The 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

Competitive 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

It 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

More 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

Reduced‐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

A 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

Fibers 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

Two 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

Thermal 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

Six 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

The 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

Five 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

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

Objective: 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.
Effects of pore‐size controlled solubility on reactive transport in heterogeneous rock
Authors: Emmanuel Simon , Berkowitz Brian
Published: March 2007

Pore‐size controlled solubility (PCS) is incorporated into continuum equations for fluid transport and porosity evolution. The physical properties of a porous domain, in particular pore‐size, can modify the effective solubility of minerals, allowing highly supersaturated fluids to exist within submicron‐scale pores of rocks; when fluid flows from small pores into larger ones, or vice versa, precipitation or dissolution may occur. Using numerical simulations, we demonstrate that the PCS mechanism can account for the filling of large pore spaces during transport though a heterogeneous rock matrix. Furthermore, depending on flow and initial conditions, the steady state porosity patterns that develop may be heterogeneous. The mechanism is expected to be of significance during diagenesis and fracture mineralization.
Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice‐albedo feedback
Authors: Austin Jay A. , Colman Steven M.
Published: March 2007

Lake Superior summer (July–September) surface water temperatures have increased approximately 2.5°C over the interval 1979–2006, equivalent to a rate of (11 ± 6) × 10−2°C yr−1, significantly in excess of regional atmospheric warming. This discrepancy is caused by declining winter ice cover, which is causing the onset of the positively stratified season to occur earlier at a rate of roughly a half day per year. An earlier start of the stratified season significantly increases the period over which the lake warms during the summer months, leading to a stronger trend in mean summer temperatures than would be expected from changes in summer air temperature alone.
Heat flow on hot spot swells: Evidence for fluid flow
Authors: Harris Robert N. , McNutt Marcia K.
Published: March 2007

We examine variability observed in heat flow determinations collected on hot spot swells. We find substantial scatter in heat flow at wavelengths of a few hundred kilometers and less at both Hawaii and Reunion, where closely spaced data exist, and large variability in the regional heat flow surveys at Cape Verde, Bermuda, and Crozet. Our preferred interpretation is that the observed variability is due to fluid flow. The presence of fluid flow admits the possibility that some heat is lost through advection such that the mean observed heat flow is less than the actual mantle flux. If so, the full magnitude of sublithospheric thermal variations may not be observed. This interpretation has important implications for understanding heat flow determinations made on hot spot swells and resulting geodynamic inferences. We suggest fluid flow may be masking variations in sublithospheric heat flux making available surface heat flow values a poor discriminator between geodynamic models for hot spot swells. Future field programs, methods of data analysis, and models should be designed to help extract a low‐frequency mantle flux disguised by a high‐noise surface filter.
Cost‐effective water quality assessment through the integration of monitoring data and modeling results
Authors: LoBuglio Joseph N. , Characklis Gregory W. , Serre Marc L.
Published: March 2007

Sparse monitoring data and error inherent in water quality models make the identification of waters not meeting regulatory standards uncertain. Additional monitoring can be implemented to reduce this uncertainty, but it is often expensive. These costs are currently a major concern, since developing total maximum daily loads, as mandated by the Clean Water Act, will require assessing tens of thousands of water bodies across the United States. This work uses the Bayesian maximum entropy (BME) method of modern geostatistics to integrate water quality monitoring data together with model predictions to provide improved estimates of water quality in a cost‐effective manner. This information includes estimates of uncertainty and can be used to aid probabilistic‐based decisions concerning the status of a water (i.e., impaired or not impaired) and the level of monitoring needed to characterize the water for regulatory purposes. This approach is applied to the Catawba River reservoir system in western North Carolina as a means of estimating seasonal chlorophyll a concentration. Mean concentration and confidence intervals for chlorophyll a are estimated for 66 reservoir segments over an 11‐year period (726 values) based on 219 measured seasonal averages and 54 model predictions. Although the model predictions had a high degree of uncertainty, integration of modeling results via BME methods reduced the uncertainty associated with chlorophyll estimates compared with estimates made solely with information from monitoring efforts. Probabilistic predictions of future chlorophyll levels on one reservoir are used to illustrate the cost savings that can be achieved by less extensive and rigorous monitoring methods within the BME framework. While BME methods have been applied in several environmental contexts, employing these methods as a means of integrating monitoring and modeling results, as well as application of this approach to the assessment of surface water monitoring networks, represent unexplored areas of research.
A comparison of alternative multiobjective calibration strategies for hydrological modeling
Authors: Fenicia Fabrizio , Savenije Hubert H. G. , Matgen Patrick , Pfister Laurent
Published: March 2007

A conceptual hydrological model structure contains several parameters that have to be estimated through matching observed and modeled watershed behavior in a calibration process. The requirement that a model simulation matches different aspects of system response at the same time has led the calibration problem toward a multiobjective approach. In this work we compare two multiobjective calibration approaches, each of which represents a different calibration philosophy. The first calibration approach is based on the concept of Pareto optimality and consists of calibrating all parameters with respect to a common set of objectives in one calibration stage. This approach results in a set of Pareto‐optimal solutions representing the trade‐offs between the selected calibration objectives. The second is a stepped calibration approach (SCA), which implies a stepwise calibration of sets of parameters that are associated with specific aspects of the system response. This approach replicates the steps followed by a hydrologist in manual calibration and develops a single solution. The comparison is performed considering the same set of objectives for the two approaches and two model structures of a different level of complexity. The difference in the two approaches, their reciprocal utility, and the practical implications involved in their application are analyzed and discussed using the Hesperange catchment case, an experimental basin in the Alzette River basin in Luxembourg. We show that the two approaches are not necessarily conflicting but can be complementary. The first approach provides useful information about the deficiencies of a model structure and therefore helps the model development, while the second attempts at determining a solution that is consistent with the data available. We also show that with increasing model complexity it becomes possible to reproduce the observations more accurately. As a result, the solutions for the different calibration objectives become less distinguishable from each other, indicating that calibration results become less dependent on the objective functions used when the model is a better representation of reality and has a higher potential to reproduce the observations.
Ordered phases of diblock copolymers in selective solvent
Authors: Grason Gregory M.
Published: March 2007

The authors propose a mean-field model to explore the equilibrium coupling between micelle aggregation and lattice choice in neutral copolymer and selective solvent mixtures. They find both thermotropic and lyotropic transitions from face-centered cubic to body-centered cubic ordered phases of spherical micelles, in agreement with experimental observations of these systems over a broad range of conditions. The stability of the nonclosed packed phase can be attributed to two physical mechanisms: the large entropy of lattice phonons near crystal melting and the preference of the intermicelle repulsions for the body-centered cubic structure when the lattice becomes sufficiently dense at higher solution concentrations. Both mechanisms are controlled by the decrease of micelle aggregation and subsequent increase of lattice density as solvent selectivity is reduced. These results shed new light on the relationship between micelle structure—“crewcut” or “hairy”—and long-range order in micelle solutions.
D atom loss in the photodissociation of the DNCN radical: Implications for prompt NO formation
Authors: Szpunar David E. , Faulhaber Ann Elise , Kautzman Kathryn E. , Crider Paul E. , Neumark Daniel M.
Published: March 2007

The photodissociation of DNCN following excitation of the C̃A″2←X̃A″2 electronic transition was studied using fast beam photofragment translational spectroscopy. Analysis of the time-of-flight distributions reveals a photodissociation channel leading to D+NCN competitive with the previously observed CD+N2 product channel. The translational energy distributions describing the D+NCN channel are peaked at low energy, consistent with internal conversion to the ground state followed by statistical decay and the absence of an exit barrier. The results suggest a relatively facile pathway for the reaction CH+N2→H+NCN that proceeds through the HNCN intermediate and support a recently proposed mechanism for prompt NO production in flames.
Drought-adaptive attributes in the Seri/Babax hexaploid wheat population
Authors: Olivares-Villegas Juan Jose , Reynolds Matthew P. , McDonald Glenn K.
Published: March 2007

Agronomic and physiological traits associated with drought adaptation were assessed within the Seri/Babax recombinant inbred line population, which was derived from parents similar in height and maturity but divergent in their sensitivity to drought. Field trials under different water regimes were conducted over 3 years in Mexico and under rainfed conditions in Australia. Under drought, canopy temperature (CT) was the single-most drought-adaptive trait contributing to a higher performance (r2 = 0.74, P < 0.0001), highly heritable (h2 = 0.65, P < 0.0001) and consistently associated with yield phenotypically (r = –0.75, P < 0.0001) and genetically [R (g) = −0.95, P < 0.0001]. CT epitomises a mechanism of dehydration avoidance expressed throughout the cycle and across latitudes, which can be utilised as a selection criteria to identify high-yielding wheat genotypes or as an important predictor of yield performance under drought. Early response under drought, suggested by a high association of CT with estimates of biomass at booting (r = −0.44, P < 0.0001), leaf chlorophyll (r = −0.22 P < 0.0001) and plant height (r = −0.64, P < 0.0001), contrast with the small relationships with anthesis and maturity (averaged, r = −0.10, P < 0.0001), and with osmotic potential (r = −0.20, P < 0.0001). Results suggest that the ability to extract water from the soil under increasing soil water deficit is a major attribute of drought adaptation. The genetic variation and transgressive segregation suggest further genomic and transcriptomic studies for unravelling the complex relationship between drought adaptation and performance under drought.
Photosynthetic responses of three C4 grasses of different metabolic subtypes to water deficit
Authors: Carmo-Silva Ana E. , Soares Ana S. , Marques da Silva Jorge , Bernardes da Silva Anabela , Keys Alfred J. , Arrabaça Maria Celeste
Published: March 2007

C4 plants are considered to be less sensitive to drought than C3 plants because of their CO2 concentrating mechanism. The C4 grasses, Paspalum dilatatum Poiret (NADP-ME), Cynodon dactylon (L.) Pers (NAD-ME) and Zoysia japonica Steudel (PEPCK) were compared in their response to water deficit imposed by the addition of polyethylene glycol to the nutrient solution in which they were grown. The effects of drought on leaf relative water content (RWC), net photosynthesis, stomatal conductance, carboxylating enzyme activities and chlorophyll a fluorescence were investigated. In C. dactylon the RWC was more sensitive, but the photosynthetic activity was less sensitive, to water deficit than in P. dilatatum and Z. japonica. The decrease of photosynthesis in P. dilatatum under water deficit was not closely related to the activities of the carboxylating enzymes or to chlorophyll a fluorescence. However, decreased activities of ribulose 1,5-bisphosphate carboxylase/oxygenase and phosphoenolpyruvate carboxylase, in addition to decreased stomatal conductance, may have contributed to the decrease of photosynthesis with drought in C. dactylon and Z. japonica. The different responses to water deficit are discussed in relation to the natural habitats of C4 grasses.