bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural investigations of polypropylene glycol (PPG) and isophorone diisocyanate (IPDI)‐based polyurethane prepolymer by 1D and 2D NMR spectroscopy
Authors: Prabhakar A. , Chattopadhyay D. K. , Jagadeesh B. , Raju K. V. S. N. 
Published: February 2005

AbstractPolyurethane prepolymers are widely used in reactive hot melt adhesives and moisture cured coatings. NCO‐terminated polyurethane of polypropylene glycol (PPG)‐1000 and isophoron diisocyanate (IPDI) with an NCO/OH ratio of 1.2:1 were prepared without any catalyst or solvent. 1D and 2D NMR spectroscopy was used for the structural investigation of the synthesized prepolymer. 1H NMR spectra and dibutylamine back‐titration were used to monitor the reaction of isocyanate groups with the hydroxyl function of PPG and to allow a good description of the evaluation of the urethane groups. The data on percentage conversion were crosschecked with 13C NMR spectroscopy in the urethane zone for the methanol endcapped prepolymer. The observations show a higher reactivity of the secondary NCO group than of the primary group. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1196–1209, 2005
An SL(2,ℝ)‐covariant, first order, κ‐supersymmetric action for the D5‐brane
Authors: Fré P. , Modesto L. 
Published: February 2005

AbstractThe new first order, rheonomic, κ–supersymmetric formalism recently introduced by us for the world‐volume action of the D3 brane is extended to the case of D5 branes. This extension requires the dual formulation of the Free Differential Algebra of type IIB supergravity in terms of 6–form gauge potentials which was so far missing and is given here. Furthermore relying on our new approach we are able to write the D5 world volume action in a manifestly SL(2,ℝ) covariant form. This is important in order to solve the outstanding problem of finding the appropriate boundary actions of D3–branes on smooth ALE manifolds with twisted fields. The application of our results to this problem is however postponed to a subsequent publication.
Compactifications on half‐flat manifolds
Authors: Gurrieri S. 
Published: February 2005

AbstractWe review various aspects of compactifications of heterotic and type II supergravities on six dimensional manifolds. In the general framework of non‐Kähler compactifications, emphasis is made on a particular class of manifolds withSU(3)‐structure named half‐flat. We recall how these manifolds appeared in the context of mirror symmetry of type II theories, providing mirror configurations to Calabi‐Yau compactifications with NS‐NS electric fluxes. In the heterotic sector, they generate a potential for all moduli, and are expected to break theE8×E8gauge group down toSO(10) ×E8in 4 dimensions.
Canadian bag‐in‐box wine under distribution channel abuse: material fatigue, flexing simulation and total closure/spout leakage investigation
Authors: Doyon Gilles , Clément Alain , Ribéreau Sabine , Morin Gérald 
Published: February 2005

AbstractBag‐in‐box (BIB) is a convenient means of wine transportation. One of the materials commonly used, metallized polyester (Met.Pet), has good oxygen barrier properties. However, little is known of the effect of handling and transportation of the BIB on O2 permeation of the flexible material and the tap under a Canadian distribution system. Our objectives were to characterize the damages to the BIB after actual transportation and distribution, correlate with a standard method for mechanical damage (Gelbo flex cracking) and validate a new capture cell design for the measurement of O2 leakage from the tap (valve and neck). Damage to Met.Pet occurred mainly near the edges and around the tap. Oxygen transmission rate ranged from 2.45 to 4.99 cm3/m2·d·atm for routes of 414–809 km, with storage times of 3–8.1 months. Storage time (r2 = 0.83; p < 0.01) was a much better predictor of damage than distance covered (r2 = 0.33; NS at α = 0.05), with respect to O2 permeation. Wear simulation using the Gelbo flex test was significantly related to O2 transmission rate (p < 0.01) and was a suitable film pre‐selection method. Converting permeation values back to an equivalent number of cycles (DMZE) shows that minimum damage measured on BIB represents about 43 flexing cycles. Up to 60% of total O2 ingress in BIB is caused by the tap, an element overlooked by actual standards. 10–16% of tap permeation was due to the neck and valve–neck interface, and the snugness of the fit was particularly sensitive to temperature under our experimental conditions. Copyright © 2005 John Wiley & Sons, Ltd.
Improving science inquiry with elementary students of diverse backgrounds
Authors: Cuevas Peggy , Lee Okhee , Hart Juliet , Deaktor Rachael 
Published: February 2005

AbstractThis study examined the impact of an inquiry‐based instructional intervention on (a) children's ability to conduct science inquiry overall and to use specific skills in inquiry, and (b) narrowing the gaps in children's ability among demographic subgroups of students. The intervention consisted of instructional units, teacher workshops, and classroom practices. The study involved 25 third‐ and fourth‐grade students from six elementary schools representing diverse linguistic and cultural groups. Quantitative results demonstrated that the intervention enhanced the inquiry ability of all students regardless of grade, achievement, gender, ethnicity, socioeconomic status (SES), home language, and English proficiency. Particularly, low‐achieving, low‐SES, and English for Speakers of Other Languages (ESOL) exited students made impressive gains. The study adds to the existing literature on designing learning environments that foster science inquiry of all elementary students. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 42: 337–357, 2005
α- and β-adrenergic control of thermogenin mRNA expression in brown adipose tissue
Authors: Jacobsson Anders , Nedergaard Jan , Cannon Barbara 
Published: February 2005

By the use of an earlier characterised cDNA clone, CIN-1, corresponding to a sequence of the mRNA coding for the brown-fat specific “uncoupling” protein, thermogenin, the amount of thermogenin mRNA found in the brown adipose tissue of mice was quantitatively investigated under different physiological and pharmacological conditions.
It was found that a 4 hr cold stress led to a 7-fold increase in the amount of thermogenin mRNA; injection of norepinephrine had a significant but smaller effect. Most notably, isoprenaline (β-agonist) and phenylephrine (α-agonist) had in themselves no effect, but when injected together were able to increase the mRNA level synergistically. In 4 hr cold-stressed mice, norepinephrine, isoprenaline and cholera toxin could all further potentiate the effect of the cold stress itself on the mRNA level. Insulin and the glucocorticoid dexamethasone both had weak stimulatory effects on the mRNA level.
It is concluded that an increase in intracellular cAMP levels is a necessary and perhaps sufficient stimulus for the increase in thermogenin gene expression. However, at least under in vivo conditions, this increase requires stimulation of both α- and β-adrenergic pathways.
Photoreaction of tyrosin-iodinated bacteriorhodopsin at low temperature
Authors: Iwasa Tatsuo , Takeda Kazuo , Tokunaga Fumio , Scherrer Peter S. , Packer Lester 
Published: February 2005

To elucidate the role of tyrosine residues in the shift of λmax and the light-driven proton pump of bacteriorhodopsin, the photochemical reaction of tyrosine-iodinated bacteriorhodopsin (tyr-mod-bR) was investigated by low-temperature spectrophotometry. After 4–5 of 11 tyrosine residues of bacteriorhodopsin were iodinated, the meta-intermediate of tyr-mod-bR in 75% glycerol solution became so stable that its decay could be observed even at room temperature and it was stable in the dark for several hours at −65°C.
Four batho-intermediates were formed by irradiation with green light (500 nm) at −170°C. Like native bacteriorhodopsin, these batho-intermediates were photoreversible at −170°C. Four corresponding meta-intermediates were also formed by irradiation at −60°C. Using the difference spectra between meta-intermediates and tyr-mod-bR, the absorption spectra of four kinds of tyr-mod-bRs, batho-intermediates, and meta-intermediates were estimated. Each was at shorter wavelengths than that of its corresponding type in native bacteriorhodopsin. The results indicate that two or more tyrosine residues have some role in determining color in native bacteriorhodopsin.
The measurement of membrane potential using optical indicators
Authors: Bashford C. Lindsay 
Published: February 2005

Conclusions
Optical methods have become established as a major experimental protocol for following membrane potential. They can provide a rapid, continuous record of the potential and have a very wide applicability. However, when used to make quantitative assertions about membrane potential, optical methods have a number of weaknesses. Even the most reliable calibration procedures depend on accurate evaluation of a small number, namely the internal ion concentration, in a large background, that is total ion levels. However, a consensus seems to be emerging that the plasma membrane potential of non-excitable cells nevertheless has considerable magnitude: typical values are −60 mV for lymphocytes (Rink et al., 1980), −20 to −100 mV, depending on metabolic load, for Ehrlich ascites tumour cells (Philo & Eddy, 1978; but see also Smith & Robinson, 1980), and −66 to −86 mV for neutrophils (Tatham et al., 1980). In our own experiments using monolayer cultures of cells grown to confluence (Bashford et al., 1981) the potential across the plasma membrane is of the order of −100 mV (see Fig. 2). Membrane potentials of similar magnitude have been found using ion-distribution methods and microelectrodes in neuroblastoma cells and lymphocytes (Deutsch et al., 1979a,b). In the latter studies ions of different charge were used to provide upper and lower estimates of the potential, the presumed effects of binding being very different for anions and cations. A similar approach, in this case the use of optical indicators of different charge, has been taken by Rink et al. (1980), and this would seem to be one way in which to diminish the uncertainties involved in dye calibration. Unfortunately many anions, particularly oxonols, form complexes with valinomycin (Lavie & Sonenberg, 1980; Rink et al., 1980), although we have found no evidence for such a complex with bis isoxazolone oxonols (J.C. Smith and C.L. Bashford, unpublished observations). It is apparent that calibration procedures not dependent on valinomycin should be sought in order to establish optical methods as a quantitative approach to the study of membrane potential.
Smoking‐gene Interaction and Disease Development: Relevance to Pancreatic Cancer and Atherosclerosis
Authors: Wang Xing Li , Wang Jian 
Published: February 2005

AbstractThere is little doubt that cigarette smoking remains a major environmental health risk that humans are facing in the twenty‐first century. Cigarette smokers are more likely to develop many forms of diseases than nonsmokers, including cancers and vascular diseases. With the availability of the human genome sequence, we become more aware of the genetic contributions to these common diseases, especially the interactive relations between environmental factors (e.g., smoking) and genes on disease susceptibility, development, and prognosis. Although smoking is responsible for up to 30% of pancreatic cancers and about 10% of cases are ascribed to genetic reasons, some genetic variants do not predispose carriers to disease development unless they are exposed to a specific adverse environment such as smoking. This smoke‐gene interaction could potentially be responsible for most of the cases. Certain polymorphisms in genes such as CYP1A1 have been shown particularly sensitive to smoking‐induced pathogenesis, including pancreatic cancer and atherosclerosis. We found that individuals with CYP1A1 CC genotype had a more than three fold increase in risk for severe coronary atherosclerosis when they smoked. Patients with endothelial nitric oxide synthase (eNOS) intron 4 27 repeat homozygotes were more likely to develop severe coronary stenosis when they smoked. On the other hand, DNA variants at the eNOS gene also dictate how smoking affects the expression of eNOS. We showed that GSTM1 deficiency was not involved in smoking‐induced vascular diseases, but p53 polymorphisms tended to modify the disease severity in smokers. We are still at an early stage of defining the pairs and mechanisms of smoke‐gene interaction, and this etiologic mechanism may hold great potential for risk assessment, treatment strategy, and prognostic predictions.
Elevated plasma levels of lipoprotein(a) in psychiatric patients: a possible contribution to increased vascular risk
Authors: Emanuele Enzo , Carlin Maria V. , D’Angelo Angela , Peros Emmanouil , Barale Francesco , Geroldi Diego , Politi Pierluigi 
Published: February 2005

AbstractAn increased incidence of adverse cardiovascular events has been reported in psychiatric patients, but the exact mechanisms underlying this association are still uncertain. Elevated plasma level of lipoprotein(a) [Lp(a)] is an independent risk factor for atherothrombotic disease in the general population. To study the implications of Lp(a) in psychiatric patients, we measured the plasma levels of Lp(a) in 74 patients with psychiatric disorders (39 schizophrenia, 10 major depression, 13 bipolar disorder and 12 personality disorder) and 74 healthy controls. The Lp(a) levels of the patient groups with schizophrenia, major depression and bipolar disorder were significantly higher than that of the control group. The median Lp(a) value of these diagnostic groups was comparable with those reported in patients with prior atherothrombotic events. On the other hand, no differences were found among personality disorder and controls. Our findings suggest that the elevation of plasma Lp(a) may contribute to increased cardiovascular risk in several patients with psychiatric disorders.
An ecosystem element added to the assessment of Norwegian spring-spawning herring: implementing predation by minke whales
Authors: Tjelmeland Sigurd , Lindstrøm Ulf 
Published: February 2005

AbstractPredation by minke whales is incorporated in the assessment model of the Norwegian spring-spawning herring stock (SeaStar) used by the ICES Working Group. Three assessment scenarios are performed and evaluated: (1) Default historic assessment where the natural mortality (M) is fixed, (2) assessment where natural mortality is estimated both for adult and juvenile herring, (3) assessment where consumption by minke whales is modelled and the predation and residual natural mortalities are estimated. The annual consumption of juvenile herring in the Barents Sea is estimated exogenously using diet data and a bioenergetic model. The estimated consumption is included in the objective function and the parameters determining the modelled consumption are estimated together with other free parameters of the model in a single operation. The estimated total natural mortality of juvenile herring is lower than the value assumed by the working group (M = 0.9) when either minke whales are included in the model (M = 0.49) or the parameter is estimated directly (M = 0.48). Assessment 3 generates 19% and 34% lower adult and juvenile stock sizes, respectively, than assessment 1, whereas assessments 2 and 3 generate relatively similar stock size estimates. The predation mortality constituted 45% and 10% of the total natural mortality of adult (M = 0.15) and juvenile herring (M = 0.49), respectively.
Availability of short amino acid sequences in proteins
Authors: Otaki Joji M. , Ienaka Shunsuke , Gotoh Tomonori , Yamamoto Haruhiko 
Published: February 2005

AbstractMuch attention is being paid to protein databases as an important information source for proteome research. Although used extensively for similarity searches, protein databases themselves have not fully been characterized. In a systematic attempt to reveal protein‐database characters that could contribute to revealing how protein chains are constructed, frequency distributions of all possible combinatorial sets of three, four, and five amino acids (“triplets,” “quartets,” and “pentats”; collectively called constituent sequences) have been examined in the nonredundant (nr) protein database, demonstrating the existence of nonrandom bias in their “availability” at the population level. Nonexistent short sequences of pentats were found that showed low availability in biological proteins against their expected probabilities of occurrence. Among them, six representative ones were successfully synthesized as peptides with reasonably high yields in a conventional Fmoc method, excluding the possibility that a putative physicochemical energy barrier in forming them could be a direct cause for the low availability. They were also expressed as soluble fusion proteins in a conventional Escherichia coli BL21Star(DE3) system with reasonably high yield, again excluding a possible difficulty in their biological synthesis. Together, these results suggest that information on three‐dimensional structures and functions of proteins exists in the context of connections of short constituent sequences, and that proteins are composed of evolutionarily selected constituent sequences, which are reflected in their availability differences in the database. These results may have biological implications for protein structural studies.
Crystallization of bacteriorhodopsin from bicelle formulations at room temperature
Authors: Faham Salem , Boulting Gabriella L. , Massey Elizabeth A. , Yohannan Sarah , Yang Dawn , Bowie James U. 
Published: February 2005

AbstractWe showed previously that high‐quality crystals of bacteriorhodopsin (bR) from Halobacterium salinarum can be obtained from bicelle‐forming DMPC/CHAPSO mixtures at 37°C. As many membrane proteins are not sufficiently stable for crystallization at this high temperature, we tested whether the bicelle method could be applied at a lower temperature. Here we show that bR can be crystallized at room temperature using two different bicelle‐forming compositions: DMPC/CHAPSO and DTPC/CHAPSO. The DTPC/CHAPSO crystals grown at room temperature are essentially identical to the previous, twinned crystals: space group P21 with unit cell dimensions of a = 44.7 Å, b = 108.7 Å, c = 55.8 Å, β = 113.6°. The room‐temperature DMPC/CHAPSO crystals are untwinned, however, and belong to space group C2221 with the following unit cell dimensions: a = 44.7 Å, b = 102.5 Å, c = 128.2 Å. The bR protein packs into almost identical layers in the two crystal forms, but the layers stack differently. The new untwinned crystal form yielded clear density for a previously unresolved CHAPSO molecule inserted between protein subunits within the layers. The ability to grow crystals at room temperature significantly expands the applicability of bicelle crystallization.
Seismic stratigraphy, buried beach ridges and contourite drifts: the Late Quaternary history of the closed Lago Cardiel basin, Argentina (49°S)
Authors: Gilli Adrian , Anselmetti Flavio S. , Ariztegui Daniel , Beres Milan , McKenzie Judith A. , Markgraf Vera 
Published: February 2005

AbstractThe results of a seismic stratigraphic analysis of a closed lake basin, Lago Cardiel, in southernmost South America are reported. Very few high‐resolution, continental records spanning the Late Quaternary have been obtained from this region. Seismic sequence stratigraphic analysis allows a reconstruction of lake level variations. Two major hiatuses of unknown age occurred during the early evolution of the basin with the deposition of an alluvial fan in a restricted area in the intervening time period. Following the development of a relatively shallow lake during the late Pleistocene and a short desiccation pulse around 11 220 14C yr BP, a transgression of over 135 m occurred at the beginning of the Holocene. The transgression was associated with the formation of beach ridges preserved in the lake stratigraphy on the floor of the modern Lago Cardiel at four different elevations. The preservation of largely unreworked beach ridges indicates a stepwise rise in the lake level. There is no seismic evidence of a major lowering of the lake below modern level during the entire Holocene. Deposition since the mid‐Holocene is marked by strong lateral differences in sediment accumulation with a depocentre slightly to the north of the basin midpoint and a pronounced mounded distribution. Seismic reflection geometries, as well as sedimentological characteristics indicate a lacustrine contourite drift covering an area of 80–100 km2. As Lago Cardiel is under the influence of westerly winds, these most likely drove lake circulation. The identification of drowned beach ridges and of contourite drifts illustrates that high‐resolution seismic stratigraphy is not only a powerful tool in reconstructing past lake level elevations for closed lake basins, but it can also provide information about the rate of lake level changes and the presence and strength of lake currents.
Morphology and facies architecture of a falling sea level strandplain, Umiujaq, Hudson Bay, Canada
Authors: FRASER CHRISTIAN , HILL PHILIP R. , ALLARD MICHEL 
Published: February 2005

AbstractCoastal strandplain deposits near Umiujaq, eastern Hudson Bay, Canada, were formed under falling relative sea level conditions resulting from postglacial isostatic uplift. Ground‐probing radar profiles across the strandplain reveal a lower progradational unit (LPU) discordantly overlain by an upper progradational unit (UPU), which were correlated with stratigraphic sections exposed in incised valley walls. The discordance is a wave erosion surface (WES) that separates fine shoreface sands of the LPU from coarse‐sand and gravel of the UPU. Major basal downlap surfaces can be traced updip into marine terraces and define downstepping wedges. The downstepping is interpreted as representing ‘autocyclic’ morphological reconfiguration rather than a response to changes in the rate of sea level fall. The internal architecture is strongly dependent on the accommodation and thus on antecedent topography. A conceptual model for strandplain deposition under falling sea level incorporates a bipartite shallowing‐upward sandy succession when sufficient accommodation is available. Where accommodation space is limited, a sharp‐based bar‐and‐beach sandbody directly overlies muddy deeper water deposits and the WES resembles a regressive surface of erosion.