bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implementing a corporate environmental strategy: establishing coordination and control within multinational companies
Authors: Epstein Marc J. , Roy Marie‐Josée 
Published: July 2006

AbstractThis article presents the results of an empirical study that investigated coordination and control within multinational companies over six key aspects of their environmental strategy. Specifically, it first examines the level of centralization of these key issues. Second, it investigates whether there is a positive relation between three variables associated with organizational complexity and the level of centralization of the environmental issues. Statistical analyses of the data obtained from a sample of 98 North American multinationals were conducted. The study's results revealed that most companies have adopted a global environmental standard to govern their worldwide business activities that is supported by strong central controls over both environmental performance evaluation of facilities and decisions regarding the development of environmental programs. Results also revealed that there are limited links between organizational complexity and most aspects of the environmental strategy. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Theoretical Study of the Full Reaction Mechanism of Human Soluble Epoxide Hydrolase
Authors: Hopmann Kathrin H. , Himo Fahmi 
Published: July 2006

AbstractThe complete reaction mechanism of soluble epoxide hydrolase (sEH) has been investigated by using the B3LYP density functional theory method. Epoxide hydrolases catalyze the conversion of epoxides to their corresponding vicinal diols. In our theoretical study, the sEH active site is represented by quantum‐chemical models that are based on the X‐ray crystal structure of human soluble epoxide hydrolase. The trans‐substituted epoxide (1S,2S)‐β‐methylstyrene oxide has been used as a substrate in the theoretical investigation of the sEH reaction mechanism. Both the alkylation and the hydrolytic half‐reactions have been studied in detail. We present the energetics of the reaction mechanism as well as the optimized intermediates and transition‐state structures. Full potential energy curves for the reactions involving nucleophilic attack at either the benzylic or the homo‐benzylic carbon atom of (1S,2S)‐β‐methylstyrene oxide have been computed. The regioselectivity of epoxide opening has been addressed for the two substrates (1S,2S)‐β‐methylstyrene oxide and (S)‐styrene oxide.
Synthesis of fuel additives on vegetable oil basis at laboratory scale
Authors: Hancsók Jenő , Bubálik Márk , Törő Mária , Baladincz Jenő 
Published: July 2006

AbstractThe aim of this work was to produce multifunctional additives on vegetable oil basis that provide not only a detergent‐dispersant effect in fuel but also other advantageous properties. Besides, the goal was to use raw materials of partly renewable origin in order to meet the biodegradability requirements. Intermediates were produced from polyisobutylene (PIB) maleic anhydride and rapeseed oil methyl ester by a radical‐initiated method. These intermediates were used to acylate polyethylene polyamines. The analytical and efficiency tests of the final products showed similar or even better DD properties compared to traditional PIB‐succinimides. The new additives also showed additional functional effects (e.g. corrosion‐inhibiting and lubricity‐improving effects).
Semiparametric variance‐component models for linkage and association analyses of censored trait data
Authors: Diao G. , Lin D.Y. 
Published: July 2006

AbstractVariance‐component (VC) models are widely used for linkage and association mapping of quantitative trait loci in general human pedigrees. Traditional VC methods assume that the trait values within a family follow a multivariate normal distribution and are fully observed. These assumptions are violated if the trait data contain censored observations. When the trait pertains to age at onset of disease, censoring is inevitable because of loss to follow‐up and limited study duration. Censoring also arises when the trait assay cannot detect values below (or above) certain thresholds. The latent trait values tend to have a complex distribution. Applying traditional VC methods to censored trait data would inflate type I error and reduce power. We present valid and powerful methods for the linkage and association analyses of censored trait data. Our methods are based on a novel class of semiparametric VC models, which allows an arbitrary distribution for the latent trait values. We construct appropriate likelihood for the observed data, which may contain left or right censored observations. The maximum likelihood estimators are approximately unbiased, normally distributed, and statistically efficient. We develop stable and efficient numerical algorithms to implement the corresponding inference procedures. Extensive simulation studies demonstrate that the proposed methods outperform the existing ones in practical situations. We provide an application to the age at onset of alcohol dependence data from the Collaborative Study on the Genetics of Alcoholism. A computer program is freely available.Genet. Epidemiol. 2006. © 2006 Wiley‐Liss, Inc.
Hypermethylation of the APC promoter but lack of APC mutations in myxoid/round‐cell liposarcoma
Authors: Sievers Sonja , Fritzsch Carla , Lehnhardt Marcus , Zahn Susanne , Kutzner Nadine , Kuhnen Cornelius , Müller Oliver 
Published: July 2006

AbstractThe adenomatous polyposis coli (APC) protein is a key component of the WNT signalling pathway wherein it acts as a scaffolding protein in controlling the level of the proto‐oncoprotein β‐catenin. Although APC has been shown to be genetically or epigenetically inactivated in a variety of carcinomas, little is known about its role in sarcoma. Liposarcomas (LPSs) are the second most common soft tissue sarcoma in adults. Despite different histology and malignancy, the myxoid and round‐cell LPSs belong to one tumour entity characterized by a specific chromosomal translocation. We assessed the extent of genetic and epigenetic inactivation of the APC gene in myxoid/round‐cell LPS. Sequencing of the mutation cluster region, the protein truncation test and a loss of heterozygosity (LOH) analysis did not reveal any genetic alterations of the APC gene in all of the liposarcoma samples. Methylation of the APC promoter was detected by methylation‐specific PCR in 9 of 20 (45%) tumours. Analysis of APC expression by semiquantitative RT‐PCR in a subset of the samples demonstrated that tumours with a methylated APC promoter showed a downregulation of the APC transcript. However, APC downregulation was not correlated with a stabilisation of the β‐catenin protein. Thus, the epigenetic regulation of the APC gene might play an important role in the pathogenesis of myxoid/round‐cell LPS. However, the impact of APC methylation on liposarcoma development is quite likely not mediated through WNT signalling. © 2006 Wiley‐Liss, Inc.
Spirulina attenuates cyclosporine‐induced nephrotoxicity in rats
Authors: Khan Mahmood , Shobha Jagdish Chandra , Mohan Iyyapu Krishna , Rao Naidu Madireddy Umamaheswara , Prayag Aruna , Kutala Vijay Kumar 
Published: July 2006

AbstractCyclosporine (CsA) causes a dose‐related decrease in renal function in experimental animals and humans. The generation of reactive oxygen species (ROS) has been implicated in CsA‐induced nephrotoxicity. It was previously shown that Spirulina, a blue‐green algae, with antioxidant properties effectively attenuated the doxorubicin‐induced cardiotoxicity in mice and cisplatin‐induced nephrotoxicity in rat. The present study investigated the nephroprotective role of Spirulina against CsA‐induced nephrotoxicity in rats. Spirulina (500 mg kg−1 b.w.) was administered orally for 3 days before and 14 days concurrently with CsA (50 mg kg‐1 b.w.). Rats treated with CsA showed nephrotoxicity as evidenced from a significant elevation in plasma urea, creatinine, urinary N‐acetyl‐β‐D‐glucosaminidase (β‐NAG) and a decrease in creatinine and lithium clearance. Pretreatment with Spirulina protected the rats from CsA‐induced nephrotoxicity. The CsA‐induced rise in plasma urea and creatinine and the decrease in creatinine and lithium clearance were attenuated by Spirulina. There was a significant increase in plasma and kidney tissue MDA with CsA. Spirulina prevented the rise in plasma and kidney tissue MDA. Histopathology of the kidney from CsA‐treated rats showed severe isometric vacuolization and widening of the interstitium. However, pretreatment with Spirulina prevented such changes, and the kidney morphology was comparable to that of the control. Spirulina treatment did not alter the blood CsA levels. These results suggest that Spirulina has a protective effect against nephrotoxicity induced by CsA. This study further supports the crucial role of the antioxidant nature of Spirulina in protecting against CsA‐induced oxidative stress. Copyright © 2006 John Wiley & Sons, Ltd.
Isotope‐ratio detection for gas chromatography
Authors: Sessions Alex L. 
Published: July 2006

AbstractInstrumentation and methods exist for highly precise analyses of the stable‐isotopic composition of organic compounds separated by GC. The general approach combines a conventional GC, a chemical reaction interface, and a specialized isotope‐ratio mass spectrometer (IRMS). Most existing GC hardware and methods are amenable to isotope‐ratio detection. The interface continuously and quantitatively converts all organic matter, including column bleed, to a common molecular form for isotopic measurement. C and N are analyzed as CO2 and N2, respectively, derived from combustion of analytes. H and O are analyzed as H2 and CO produced by pyrolysis/reduction. IRMS instruments are optimized to provide intense, highly stable ion beams, with extremely high precision realized via a system of differential measurements in which ion currents for all major isotopologs are simultaneously monitored. Calibration to an internationally recognized scale is achieved through comparison of closely spaced sample and standard peaks. Such systems are capable of measuring 13C/12C ratios with a precision approaching 0.1‰ (for values reported in the standard delta notation), four orders of magnitude better than that typically achieved by conventional “organic” mass spectrometers. Detection limits to achieve this level of precision are typically <1 nmol C (roughly 10 ng of a typical hydrocarbon) injected on‐column. Achievable precision and detection limits are correspondingly higher for N, O, and H, in that order.
Elevated temperature and temperature programming in conventional liquid chromatography – fundamentals and applications
Authors: Vanhoenacker Gerd , Sandra Pat 
Published: July 2006

AbstractTemperature, as a powerful variable in conventional LC is discussed from a fundamental point of view and illustrated with applications from the author's laboratory. Emphasis is given to the influence of temperature on speed, selectivity, efficiency, detectability, and mobile phase composition (green chromatography). The problems accompanying the use of elevated temperature and temperature programming in LC are reviewed and solutions are described. The available stationary phases for high temperature operation are summarized and a brief overview of recent applications reported in the literature is given.
Lewis acid induced additions to unsaturated fatty compounds IV: Synthesis of cyclopentenones from Friedel‐ Crafts acylation products of unsaturated fatty compounds with α,β‐unsaturated acyl chlorides
Authors: Metzger Jürgen O. , Biermann Ursula 
Published: July 2006

AbstractThe ethylaluminium dichloride induced Friedel‐ Crafts acylation of unsaturated fatty compounds such as oleic acid (1a), methyl oleate (1b) and 10‐undecenoic acid (9b) and furthermore of 1‐octene (9a) with α,β‐unsaturated acyl chlorides e.g. crotonic acid chloride (2a) and acrylic acid chloride (2b) gave the corresponding allyl vinyl ketones. Nazarov cyclizations of the acylation products 3a/4a, 3b/4b, 10a and 10b afforded the alkyl substituted 2‐cyclopentenones 5a/6a, 5b/6b, 11a/12a and 11b/12b. Catalytic hydrogenation of 5b/6b and 11b/12b gave the respective saturated cyclic products 7b/8b and 13b/14b as diastereomeric mixtures.
Developmental changes in cell proliferation in the auditory midbrain of the bullfrog, Rana catesbeiana
Authors: Simmons Andrea Megela , Chapman Judith A. , Brown Rebecca A. 
Published: July 2006

AbstractWe examined patterns of cell proliferation in the auditory midbrain (torus semicircularis) of the bullfrog, Rana catesbeiana, over larval and early postmetamorphic development, by visualizing incorporation of 5‐bromo‐2′‐deoxyuridine (BrdU) in cycling cells. At all developmental stages, BrdU‐labeled cells were concentrated around the optic ventricle. BrdU‐labeled cells also appeared within the torus semicircularis itself, in a stage‐specific manner. The mitotic index, quantified as the percent of BrdU‐positive cells outside the ventricular zone per total cells available for label, varied over larval development. Mitotic index was low in hatchling, early larval, and late larval stages, and increased significantly in deaf period, metamorphic climax, and froglet stages. Cell proliferation was higher in metamorphic climax than at other stages, suggesting increased cell proliferation in preparation for the transition from an aquatic to an amphibious existence. The change in mitotic index over development did not parallel the change in the total numbers of cells available for label. BrdU incorporation was additionally quantified by dot‐blot assay, showing that BrdU is available for label up to 72 h postinjection. The pattern of change in cell proliferation in the torus semicircularis differs from that in the auditory medulla (dorsal medullary nucleus and superior olivary nucleus), suggesting that cell proliferation in these distinct auditory nuclei is mediated by different underlying mechanisms. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 1212–1224, 2006
Attitudes towards sex selection in the Western world
Authors: Van Balen Frank 
Published: July 2006

AbstractIt appears that in most Western countries, son preference is somewhat stronger than daughter preference. However, when one considers the preference of women it looks as though the opposite pattern is emerging. There is a considerable social acceptance of ‘light’ methods of sex selection (such as diets), even though these methods are not proven to be effective. The inclination to use sperm separation methods appears to be greater in the United States than in some European countries. There are indications that a preference for boys or for girls is associated with attitudes towards technology, child‐rearing style and the stereotyping of boys or girls. Copyright © 2006 John Wiley & Sons, Ltd.
Noninvasive detection of fetal sex: the laboratory diagnostician's view
Authors: Guetta Esther 
Published: July 2006

AbstractToward the end of the twentieth century it was discovered that cell‐free fetal DNA sequences could be detected in maternal blood plasma. Initially, Y‐chromosome sequences originating from male fetuses were targeted in cell‐free DNA extracted from maternal plasma in order to demonstrate proof of this concept towards the development of noninvasive prenatal diagnosis methods. Clinical application of this approach is now possible. Fetal sex can be detected through a procedure that is noninvasive with respect to the fetus. Specifically, the presence of Y‐chromosome sequences in maternal blood plasma indicates that the fetus is male, whereas lack of a signal will indicate that the fetus is female. Fetal sex can be detected very early, from at least the 7th week of pregnancy (and even earlier, according to several studies), about two months before this information is available through ultrasound scanning.Although the controversial issue of fetal sexing is not new, it is expected that with the availability of an accurate noninvasive test, public interest will rise. It is therefore imperative that an authorized committee of experts in each country generates an official policy regarding application of the test. Copyright © 2006 John Wiley & Sons, Ltd.
Predicting transmembrane β‐barrels and interstrand residue interactions from sequence
Authors: Waldispühl J. , Berger Bonnie , Clote Peter , Steyaert Jean‐Marc 
Published: July 2006

AbstractTransmembrane β‐barrel (TMB) proteins are embedded in the outer membrane of Gram‐negative bacteria, mitochondria, and chloroplasts. The cellular location and functional diversity of β‐barrel outer membrane proteins (omps) makes them an important protein class. At the present time, very few nonhomologous TMB structures have been determined by X‐ray diffraction because of the experimental difficulty encountered in crystallizing transmembrane proteins. A novel method using pairwise interstrand residue statistical potentials derived from globular (nonouter membrane) proteins is introduced to predict the supersecondary structure of transmembrane β‐barrel proteins. The algorithm transFold employs a generalized hidden Markov model (i.e., multitape S‐attribute grammar) to describe potential β‐barrel supersecondary structures and then computes by dynamic programming the minimum free energy β‐barrel structure. Hence, the approach can be viewed as a “wrapping” component that may capture folding processes with an initiation stage followed by progressive interaction of the sequence with the already‐formed motifs. This approach differs significantly from others, which use traditional machine learning to solve this problem, because it does not require a training phase on known TMB structures and is the first to explicitly capture and predict long‐range interactions. TransFold outperforms previous programs for predicting TMBs on smaller (≤200 residues) proteins and matches their performance for straightforward recognition of longer proteins. An exception is for multimeric porins where the algorithm does perform well when an important functional motif in loops is initially identified. We verify our simulations of the folding process by comparing them with experimental data on the functional folding of TMBs. A Web server running transFold is available and outputs contact predictions and locations for sequences predicted to form TMBs. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Oceanic Evidence for the Mechanism of Rapid Northern Hemisphere Glaciation
Authors: Ruddiman W. F. , McIntyre A. , Niebler-Hunt V. , Durazzi J. T. 
Published: July 2006

AbstractThe oxygen isotopic stage 5/4 boundary in deep-sea sediments marks a prominent interval of northern hemisphere ice-sheet growth that lasted about 10,000 yr. During much of this rapid ice growth, the North Atlantic Ocean from at least 40°N to 60°N maintained warm sea-surface temperatures, within 1° to 2°C of today's subpolar ocean. This oceanic warmth provided a local source of moisture for ice-sheet accretion on the adjacent continents. The unusually strong thermal gradient off the east coast of North America (an “interglacial” ocean alongside a “glacial” land mass) also should have directed low-pressure storms from warm southern latitudes north-ward toward the Laurentide Ice Sheet. In addition, minimal calving of ice into the North Atlantic occurred during most of the stage 5/4 transition, indicative of ice retention within the continents. Diminished summer and autumn insolation, a warm subpolar ocean, and minimal calving of ice are conducive to rapid and extensive episodes of northern hemisphere ice-sheet growth.
Eigenvector Analysis of Reconstructed Holocene July Temperature Departures over Northern Canada
Authors: Andrews John T. , Diaz Henry F. 
Published: July 2006

AbstractJuly temperatures for the past 6000 yr at 11 sites in northern Canada have been predicted by transfer-function equations. Normalized departures from the mean of each time series at 250-yr intervals are analyzed by principal component (eigenvector) analysis. An initial analysis included 9 sites and the first three principal components accounted for 85.7% of the variance. Maps of the loadings on the principal components show broad spatial coherence on all three components. Temporal coefficients (principal component scores) illustrate major regional and local midsummer temperature variations. An additional 2 sites were then included but the spatial pattern of the loadings remained essentially unchanged. A further test of this approach, with a view toward predicting paleoclimates of northern regions, was to use the spatial coefficients (loadings) to estimate the July temperature departures at an “unknown” site (Long Lake, Keewatin). This reconstruction compares favorably with an independent transfer-function reconstruction (Kay, 1979). Power spectrum analysis of the significant principal component scores (temperature departures) over the 6000 yr showed that the temporal fluctuations associated with the first three principal components follow a “red noise” spectrum, indicative of strong persistence in the reconstructed climatic records. The scores on the fourth principal component approximate a “white noise” spectrum. A peak in power between 2000 and 3000 yr occurs in the variance spectrum of the second principal component (significance 10%). We conclude that eigenvector analysis of Holocene paleoclimatic data has considerable power and may be useful for identifying regional and local climatic variations.
Paleoclimatic Significance of Lake-Level Fluctuations in the Lahontan Basin
Authors: Benson L.V. 
Published: July 2006

AbstractAn energy flux balance model has been developed which treats evaporation as a function of air temperature, surface water temperature, precipitable water aloft, the amount, height, and type of sky cover, and the optical air mass. The model has been used to estimate the mean historical evaporation rate for Pyramid Lake, Nevada, using as input climatic data from the Reno area averaged over the period 1950–1975. Estimated and measured values of the mean annual evaporation rate were found to be in good agreement. The model was used to simulate changes in the level, the surface area, and the volume of paleo Lake Lahontan. In particular, possible climatic states responsible for past high stands (1270 and 1330 m) were investigated. A conservative range of discharge values was used in the calculations. Results of the simulations indicate the fundamental importance of sky cover in the creation and destruction of large lake systems.
Interstadial Proboscidean from South-Central Alaska: Implications for Biogeography, Geology, and Archeology
Authors: Thorson Robert M. , Dixon E. James , Smith George S. , Batten Alan R. 
Published: July 2006

AbstractIn 1980 a large proboscidean femur, probably Mammuthus sp., was found in situ in a bluff exposure at the mouth of the Tyone River in the northwestern part of the Copper River Basin, Alaska. The regional setting, stratigraphy, radiocarbon chronology, flora, and implications of the fossil locality, which represents the first documented occurrence of Pleistocene terrestrial mammalian fauna in southern Alaska, are described. Radiocarbon dates and stratigraphic relations at the site indicate that the sediments containing the fossil accumulated during the transition from interstadial to glacial conditions during terminal middle Wisconsin time. During this interval the immediate vicinity was unforested and large areas of south-central Alaska may have been available for faunal and possibly human habitation. This documented find, dated at 29,450 ± 610 14C yr B.P., extends the known range for Pleistocene mammals and possibly steppe-tundra conditions south-ward at least 150 km, and suggests that mountain passes through the Alaska Range to the north were ice free during the last part of the middle Wisconsin interstadial.