bluuebunny/crossref_metadata_2025_split huggingface dataset:
A first‐principles DFT study of UN bulk and (001) surface: Comparative LCAO and PW calculations
Authors: Evarestov R. A. , Bandura A. V. , Losev M. V. , Kotomin E. A. , Zhukovskii Yu. F. , Bocharov D. 
Published: May 2008

AbstractLCAO and PW DFT calculations of the lattice constant, bulk modulus, cohesive energy, charge distribution, band structure, and DOS for UN single crystal are analyzed. It is demonstrated that a choice of the uranium atom relativistic effective core potentials considerably affects the band structure and magnetic structure at low temperatures. All calculations indicate mixed metallic‐covalent chemical bonding in UN crystal with U5f states near the Fermi level. On the basis of the experience accumulated in UN bulk simulations, we compare the atomic and electronic structure as well as the formation energy for UN(001) surface calculated on slabs of different thickness using both DFT approaches. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Utilizing cool posing narrative and technique as leadership strategies among underrepresented individuals
Authors: Cross, III George M. 
Published: May 2008

Abstract“Cool posing” narrative and technique—or story and style—has implications for changes in how schools and organizations think about leadership. Cool posing is showing restrained emotion to gain advantages through the use of counterpoint to puzzle and baffle rivals. The intention to be paradoxical and confusing aids the narration of appropriate techniques that offset unfavorable situations and images. Cool posing is as much a part of some underrepresented groups' performance as their sense of self, and as valuable. This strategy is frequently exhibited orally through metaphor, which transforms facts into novel accounts of reality. It is as though the ability to comprehend their experience through cool posing provides many with “the only ways to perceive and experience much of the world” (Lakoff & Johnson, 1980, p. 239). Leaders in schools and organizations could benefit by implementing the strategies suggested here that seek stability and flexibility for those underrepresented individuals traditionally studying, working, and living in less than adequate conditions. Findings suggest the consideration of additional intellectual dimensions aside from the traditional logical and mathematical ones as indicators of valid and reliable aptitude. These further dimensions include the interrelated elements of cool posing, which arespirituality(a vitalistic approach to life),verve(high levels of stimulation),movement(the interweaving of rhythm and dance),harmony(one's fate interrelates with others'),emotion(an emphasis on feelings),orality(a preference for both speaking and listening performances),expressive individualism(the cultivation of spontaneous expression),personal time(the belief that time is passing through a social space), andcommunalism(a commitment to social connectedness) (Boykins, as cited in Majors, 1987/2003a). Leaders need to broaden their ideas of standard leadership and become transformational and transformed to respond to less heard voices that scream as loudly as those that benefit through full representation. Innovative leaders can emerge from underrepresented groups and thrive in industries that become skilled at converting deficit orientations to resource orientations through “patience, a certain flexibility in world view, and a generous tolerance” (Lakoff & Johnson, p. 231). Knowledge from this study may equip teachers and leaders in multiethnic schools and organizations to respond empathetically across racial and ethnic boundaries of difference.
Leadership preferences of a generation Y cohort: A mixed‐methods investigation
Authors: Dulin Linda 
Published: May 2008

AbstractPresently there are four generational cohorts in the workplace. Born from 1977 to 1997, the youngest cohort group, Generation Y, has 81 million members, of whom over 29 million are already in the workplace. The importance of leader‐subordinate relationships in the workplace has been confirmed. In recognizing this, leaders must identify and adapt to the era‐shaped needs of employees, who cannot fully participate in organizational life if their most urgent needs are not being met. The goal of this study was to determine leadership preferences of a Gen Y cohort as a means to enhance workplace relationships in the 21st‐century organization. A sequential, mixed‐methods study was employed to explore leadership preferences of a Gen Y cohort. Initially, focus‐group interviews were used to generate leadership themes. Based on these themes, an instrument was designed, and Gen Y business students from three higher education institutions were surveyed. Confirmatory factor analysis (CFA) was used to test the themes. Five leadership themes emerged in the focus groups and were confirmed through CFA.
Ossification sequence of the avian order anseriformes, with comparison to other precocial birds
Authors: Maxwell Erin E. 
Published: May 2008

AbstractOssification sequences are poorly known for most amniotes, and yet they represent an important source of morphogenetic, phylogenetic, and life history information. Here, the author describes the ossification sequences of three ducks, the Common Eider Somateria mollissima dresseri, the Pekin Duck Anas platyrhynchos, and the Muscovy Duck Cairina moschata. Sequence differences exist both within and among these species, but are generally minor. The Common Eider has the most ossified skeleton prior to hatching, contrary to what is expected in a subarctic migrant species. This may be attributed to a tradeoff between growth rate and locomotory performance. Growth rate is higher in hatchlings with more cartilaginous skeletons, but this may compromise locomotion. No major ossification sequence differences were observed in the craniofacial skeleton when compared with Galliformes, which suggests that the influence of adult morphology on ossification sequence might be relatively minor in many taxa. Galliformes and Anseriformes, while both highly ossified at hatching, differ in the location of their late‐stage ossification centers. In Anseriformes, these are most often located in the appendicular skeleton, whereas in Galliformes they are in the thoracic region and form the ventilatory apparatus. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
Thermodynamics of T‐cell receptor–peptide/MHC interactions: progress and opportunities
Authors: Armstrong Kathryn M. , Insaidoo Francis K. , Baker Brian M. 
Published: May 2008

Abstractαβ T‐cell receptors (TCRs) recognize peptide antigens presented by class I or class II major histocompatibility complex molecules (pMHC). Here we review the use of thermodynamic measurements in the study of TCR–pMHC interactions, with attention to the diversity in binding thermodynamics and how this is related to the variation in TCR–pMHC interfaces. We show that there is no enthalpic or entropic signature for TCR binding; rather, enthalpy and entropy changes vary in a compensatory manner that reflects a narrow free energy window for the interactions that have been characterized. Binding enthalpy and entropy changes do not correlate with structural features such as buried surface area or the number of hydrogen bonds within TCR–pMHC interfaces, possibly reflecting the myriad of contributors to binding thermodynamics, but likely also reflecting a reliance on van't Hoff over calorimetric measurements and the unaccounted influence of equilibria linked to binding. TCR–pMHC binding heat capacity changes likewise vary considerably. In some cases, the heat capacity changes are consistent with conformational differences between bound and free receptors, but there is little data indicating these conformational differences represent the need to organize disordered CDR loops. In this regard, we discuss how thermodynamics may provide additional insight into conformational changes occurring upon TCR binding. Finally, we highlight opportunities for the further use of thermodynamic measurements in the study of TCR–pMHC interactions, not only for understanding TCR binding in general, but also for understanding specifics of individual interactions and the engineering of TCRs with desired molecular recognition properties. Copyright © 2008 John Wiley & Sons, Ltd.
Chemical composition and insecticidal properties of Origanum glandulosum (Desf.) essential oil from Algeria
Authors: Khalfi Ouassila , Sahraoui Naima , Bentahar Fatiha , Boutekedjiret Chahrazed 
Published: May 2008

AbstractBACKGROUND: To find natural compounds with insecticidal properties which could be an alternative to synthetic insecticides, oregano essential oil was tested against the insect Rhizopertha dominica devastating stored cereals.RESULTS: Oregano oils were isolated by steam distillation, analysed by gas chromatography and gas chromatography–mass spectrometry and investigated for their insecticidal activities against Rhizopertha dominica. Contact and fumigant toxicities of global oil and three of its fractions recovered respectively after 2 h and after 0–2.5, 2.5–5 and 5–10 min of extraction were tested using the filter paper method. Eighteen components, representing 92.6% of the oil, were identified. The major components were thymol (38.8%), carvacrol (32.9%), p‐cymene (7.9%) and γ‐terpinene (5.1%). Toxicity tests showed that insect mortality increases with the concentration used (0.39%, 0.78%, 1.56%, 3.12% and 6.24%V). For all concentrations, the contact effect of global oil and fraction F2 was better than the fumigant effect. Whereas fractions F1 and F3 were more toxic by fumigation for concentrations lower or equal to 1.56%, their contact effect was more significant for concentrations higher than 1.56%.CONCLUSION: These results suggest that oregano oil has important insecticidal properties and may be useful as a natural grain protectant against Rhizopertha dominica to replace synthetic insecticides. Copyright © 2008 Society of Chemical Industry
Characterizing diversity in composition and pasting properties of tuber flour in yam germplasm (Dioscorea spp.) from Southern Ethiopia
Authors: Tamiru Muluneh , Maass Brigitte L , Pawelzik Elke 
Published: May 2008

AbstractBACKGROUND: Studies on composition and functional properties in germplasm collections are important in determining their diversity and suitability for food and non‐food applications. The diversity in 65 yam accessions collected from Southern Ethiopia and belonging largely to a yet unknown species and to Dioscorea bulbifera L. (aerial yam) was analyzed based on protein, starch and amylose contents, and pasting properties of tuber flour, applying descriptive and multivariate statistics.RESULT: Starch content varied from 65.2% to 76.6% dry matter, while the protein content range was 6.4–13.4% dry matter. Amylose represented between 7.1% and 30.6% of the starch fraction, and was negatively correlated (P < 0.01) with starch content. UPGMA clustering and principal component analysis clearly distinguished aerial yam from those accessions with underground tubers. The first four principal components accounted for 78% of the total variability, and were highly correlated with pasting parameters.CONCLUSION: The extent of diversity detected among accessions studied showed scope for improving the crop through selection of landraces with desirable characteristics. Similar investigations on tubers grown under different environmental conditions and additional data on physicochemical properties of isolated starch will be useful in evaluating the potential of yam for food and non‐food applications. Copyright © 2008 Society of Chemical Industry
Time‐ and Temperature‐Dependent Fracture Mechanics of Polymers: General Aspects at Monotonic Quasi‐Static and Impact Loading Conditions
Authors: Lach Ralf , Grellmann Wolfgang 
Published: May 2008

AbstractWell‐defined correlations exist between the maxima in mechanical loss factor and the local maxima in temperature‐ or loading‐speed‐dependent fracture toughness. The non‐linear viscoelastic fracture processes and small‐strain deformations are characterised by the same Arrhenius‐type activation enthalpies. The local increase in toughness is linearly correlated with the relaxation strength of molecular relaxation processes. Stable crack propagation can be understood as a three‐phase process resulting in steady‐state stable crack growth. The normalised steady‐state crack‐tip‐opening displacement is independent of matrix material, temperature and loading speed.magnified image
A Defect‐Free Ring Polymer: Size‐Controlled Cyclic Poly(tetrahydrofuran) Consisting Exclusively of the Monomer Unit
Authors: Tezuka Yasuyuki , Ohtsuka Tatsuroh , Adachi Kaoru , Komiya Ryota , Ohno Noriyoshi , Okui Norimasa 
Published: May 2008

AbstractA series of size‐controlled, cyclic poly(tetrahydrofuran)s ($\overline M _{{\rm n,NMR}}$ of 4 400–8 600) that consist exclusively of the monomer, i.e., oxytetramethylene, unit (I) have been prepared in high yield through the metathesis polymer cyclization of a telechelic precursor having allyl groups, 1, in the presence of a Grubbs catalyst, and the subsequent hydrogenation of the linking, i.e., 2‐butenoxy, unit in the presence of an Adams' catalyst (PtO2). A remarkable topology effect has subsequently been observed upon the isothermal crystallization of these two model polymers, showing distinctive spherulite growth rates and spherulite morphologies in comparison with the relevant linear poly(tetrahydrofuran) counterpart that has ethoxy end groups (II).magnified image
A pilot study to determine the short‐term effects of a low glycemic load diet on hormonal markers of acne: A nonrandomized, parallel, controlled feeding trial
Authors: Smith Robyn , Mann Neil , Mäkeläinen Henna , Roper Jessica , Braue Anna , Varigos George 
Published: May 2008

AbstractObservational evidence suggests that dietary glycemic load may be one environmental factor contributing to the variation in acne prevalence worldwide. To investigate the effect of a low glycemic load (LGL) diet on endocrine aspects of acne vulgaris, 12 male acne sufferers (17.0 ± 0.4 years) completed a parallel, controlled feeding trial involving a 7‐day admission to a housing facility. Subjects consumed either an LGL diet (n = 7; 25% energy from protein and 45% from carbohydrates) or a high glycemic load (HGL) diet (n = 5; 15% energy from protein, 55% energy from carbohydrate). Study outcomes included changes in the homeostasis model assessment of insulin resistance (HOMA‐IR), sex hormone binding globulin (SHBG), free androgen index (FAI), insulin‐like growth factor‐I (IGF‐I), and its binding proteins (IGFBP‐I and IGFBP‐3). Changes in HOMA‐IR were significantly different between groups at day 7 (–0.57 for LGL vs. 0.14 for HGL, p = 0.03). SHBG levels decreased significantly from baseline in the HGL group (p = 0.03), while IGFBP‐I and IGFBP‐3 significantly increased (p = 0.03 and 0.03, respectively) in the LGL group. These results suggest that increases in dietary glycemic load may augment the biological activity of sex hormones and IGF‐I, suggesting that these diets may aggravate potential factors involved in acne development.
Apple polyphenols inhibit plasma CETP activity and reduce the ratio of non‐HDL to HDL cholesterol
Authors: Lam Cheuk Kai , Zhang Zesheng , Yu Hongjian , Tsang Suk‐Ying , Huang Yu , Chen Zhen Yu 
Published: May 2008

AbstractPrevious reports demonstrated that hypocholesterolemic activity of apple was associated with its pectin and fiber. This report was to investigate the effect of apple polyphenols (AP) on blood cholesterol level and gene expression of cholesterol‐regulating enzymes in Golden Syrian hamsters maintained on a 0.1% cholesterol diet. It was found that dietary supplementation of 0.3 or 0.6% of AP did not affect plasma total cholesterol (TC), but it increased HDL cholesterol (HDL‐C) and decreased non‐HDL‐C, thus leading to a lower ratio of non‐HDL‐C to HDL‐C. Plasma total triacylglycerol (TG) level was also significantly reduced when hamsters were fed a diet supplemented with 0.6% AP. Western blot analysis did not find any effect of AP on sterol regulatory element‐binding protein 2 (SREBP‐2), LDL receptor (LDLR), 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase (HMGR), and cholesterol‐7α‐hydroxylase (CYP7A). Most interesting was that supplementation of AP had no effect on protein abundance of plasma cholesteryl ester transport protein (CETP), but it suppressed plasma CETP activity. A series ofin vitroassays confirmed that AP inhibited CETP in a dose dependent manner. It was concluded that AP favorably improved distribution of cholesterol in lipoproteins, most likely, by its inhibition on CETP activity.
Wogonin, a bioactive flavonoid in herbal tea, inhibits inflammatory cyclooxygenase‐2 gene expression in human lung epithelial cancer cells
Authors: Chen Lih‐Geeng , Hung Liang‐Yi , Tsai Kun‐Wei , Pan Ying‐Shia , Tsai Yi‐Da , Li Yi‐Zhen , Liu Yi‐Wen 
Published: May 2008

AbstractWogonin, a naturally occurring plant flavonoid, is isolated from Chinese herbal plantsScutellaria baicalensisGeorgi andS. barbataD. Don. The extract ofS. baicalensisGeorgi has been added to an assortment of health drinks or food supplements. Wogonin has been reported to exhibit anticancer and anti‐inflammatory properties. Cyclooxygenase‐2 (COX‐2) is a key enzyme in the production of prostaglandins in inflammatory conditions. In this study, the effect of wogonin on phorbol 12‐myristate 13‐acetate (PMA)‐induced COX‐2 expression was investigated. It showed that wogonin inhibited PMA‐induced COX‐2 protein and mRNA levels in human lung epithelial cancer cells, and the mechanism of this inhibition was at the transcriptional level by using COX‐2 gene promoter assay. Among various signal inhibitors, the mitogen‐activated protein kinase kinase 1/2 (MEK1/2) inhibitor U0126 also inhibited PMA‐induced COX‐2 expression and COX‐2 promoter activation. The activity of AP‐1‐driven promoter, but not nuclear factor‐kappa B (NF‐κB), was inhibited by U0126. The data indicated that MEK1/2‐AP‐1 is very important for PMA‐induced COX‐2 expression. Wogonin also inhibited PMA‐induced AP‐1 activation and the expression of c‐Jun, a key component of AP‐1. Taken together, it is suggested that wogonin inhibits PMA‐induced COX‐2 gene expression by inhibiting c‐Jun expression and AP‐1 activation in A549 cells.
Analysis of Saccharomyces cerevisiae null allele strains identifies a larger role for DNA damage versus oxidative stress pathways in growth inhibition by selenium
Authors: Seitomer Eden , Balar Bharvi , He Dongming , Copeland Paul R. , Kinzy Terri Goss 
Published: May 2008

AbstractSelenium toxicity is a growing environmental concern due to widespread availability of high‐dose selenium supplements and the development of high‐selenium agricultural drainage basins. To begin to analyze the effects of selenium toxicity at the genetic level, we have systematically determined which genes are involved in responding to high environmental selenium using a collection of viable haploid null allele strains of Saccharomyces cerevisiae representing three major stress pathways: the RAD9‐dependent DNA repair pathway, the RAD6/RAD18 DNA damage tolerance pathway, and the oxidative stress pathway. A total of 53 null allele strains were tested for growth defects in the presence of a range of sodium selenite and selenomethionine (SeMet) concentrations. Our results show that ∼︁64–72% of the strains lacking RAD9‐dependent DNA repair or RAD6/RAD18 DNA damage tolerance pathway genes show reduced growth in sodium selenite versus ∼︁28–36% in SeMet. Interestingly both compounds reduced growth in ∼︁21–25% of the strains lacking oxidative stress genes. These data suggest that both selenite and SeMet are likely inducing DNA damage by generating reactive species. The anticipated effects of loss of components of the oxidative stress pathway were not observed, likely due to apparent redundancies in these gene products that may keep the damaging effects in check.
The Role of Allylanisole in Metallocene‐Catalyzed Propylene Polymerization and Synthesis of End‐Capped Oligomers
Authors: Atiqullah Muhammad , Akhtar Muhammad N. , Tinkl Michael , Ahmed Neaz 
Published: May 2008

AbstractPropylene was copolymerized with allylanisole (AA) using Me2Si(Ind)2ZrCl2 and Et(Ind)2ZrCl2, and the methylaluminoxane MAO cocatalyst at 70 °C and a cocatalyst to catalyst (Al:Zr) molar ratio of 1 000. It was fed at 8.5 bar(g). The weight‐average molecular weight, $\overline M _{\rm w}$, for both metallocenes decreased as the AA feed concentration increased. Therefore, allylanisole acted as an in situ chain transfer agent. The chain transfer constants, ktr/kp, of AA for Et(Ind)2ZrCl2 and Me2Si(Ind)2ZrCl2 turned out to be 0.33 and 0.40, respectively. The characterization of the resulting products by 1H NMR demonstrated that AA end‐capped the isotactic poly(propylene) chains which showed to be low molecular weight oligomers; 4.96 × 103 ≤ $\overline M _{\rm w}$ ≤ 9.80 × 103. An appropriate chain transfer mechanism for AA has been proposed.magnified image
Excellent anti‐bacterial activity and surface properties of polyamide‐6 films modified with argon‐plasma and methyl diallyl ammonium salt‐graft
Authors: Yao Wei‐Hua , Chen Jui‐Chin , Chen Cheng‐Chi 
Published: May 2008

AbstractIn this study, the effect of argon‐plasma treatment on the grafting of methyl diallyl ammonium salt (MDAA) onto polyamide‐6 film and the anti‐bacterial and surface properties of the plasma‐ and graft‐treated film were investigated. The grafting amounts of MDAA caused by argon‐plasma treatment increased with the increase in the plasma exposure time and plasma power. The analyses of Fourier transform infrared (FT‐IR) spectroscopy and electron spectroscopy for chemical analysis (ESCA) spectra revealed that the epoxy and vinyl groups of MDAA could be grafted on the argon‐plasma treated polyamide‐6 film. The survey spectra of ESCA, the patterns of atomic force microscopy (AFM), and the spectra from scanning electron microscopy (SEM) were employed to certify the surface modification of argon‐plasma treated and the argon‐plasma treated/MDAA grafted polyamide‐6 films. Argon‐plasma treatment could generate the functional group and increase the roughness on the surface of polyamide‐6 film. This phenomenon could enhance the grafting effect of MDAA. The anti‐bacterial property of argon‐plasma treated/MDAA grafted polyamide‐6 film was excellent. This argon‐plasma treated/MDAA grafted polyamide‐6 film was expected to be applied on the field of packing. Copyright © 2008 John Wiley & Sons, Ltd.
Fabrication and properties of mineralized collagen‐chitosan/hydroxyapatite scaffolds
Authors: Zhao Haiguang , Ma Lie , Gao Changyou , Shen Jiacong 
Published: May 2008

AbstractA hydroxyapatite (HAp)/biopolymer composite scaffold was fabricated by mineralizing a crosslinked collagen/chitosan, which was pre‐mineralized with Ca2+ and phosphate salts, in simulated body fluid (SBF) for only 24 hr. A self‐organized structure similar to bone is expected. Microstructures of the crosslinked collagen/chitosan scaffold, the pre‐mineralized collagen–chitosan scaffold (CCS), and the mineralized collagen‐chitosan/HAp scaffolds (MCCHS) were characterized by scanning electron microscopy (SEM), revealing non‐alteration of the porous structure and formation of the HAp particles. X‐ray diffractometer (XRD) confirmed the crystalline structure of the HAp. Thermal gravimetric analysis found that more HAp particles were formed when the CCSs were pre‐mineralized in a higher concentration of Ca2+. Water‐uptake ratio of the crosslinked CCS was ∼160, decreased to ∼120 after incubating in Ca2+ solution, and further decreased to ∼20 after mineralization. Mechanical strength of the CCS was improved significantly after the in situ mineralization too. The method introduced here may be potentially applied to obtain other biopolymer/HAp composite in a short period. Copyright © 2008 John Wiley & Sons, Ltd.