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Various Positions (various + position)
Selected AbstractsThe cranial morphology of Kayentachelys, an Early Jurassic cryptodire, and the early history of turtlesACTA ZOOLOGICA, Issue 3 2010Eugene S. Gaffney Abstract Gaffney, E.S. and Jenkins, F.A., Jr. 2010. The cranial morphology of Kayentachelys, an Early Jurassic cryptodire, and the early history of turtles. , Acta Zoologica (Stockholm) 91: 335,368 The skull morphology of Kayentachelys aprixGaffney et al., 1987, a turtle from the Early Jurassic Kayenta Fm of northern Arizona, demonstrates the presence of cryptodiran synapomorphies in agreement with Gaffney et al. (1987, 1991, 2007), and contrary to the conclusions of Sterli and Joyce (2007), Joyce (2007), Sterli (2008), and Anquetin et al. (2008). Specific characters found in Kayentachelys and diagnostic of cryptodires include the processus trochlearis oticum, the curved processus pterygoideus externus with a vertical plate, and the prefrontal,vomer contact, which are confirmed as absent in the outgroups, specifically the Late Triassic Proganochelys. The Joyce (2007) analysis suffers from the reduction of the signal from skull characters, with a consequently greater reliance on shell characters, resulting in pleurodires being resolved at various positions within the cryptodires. Kayentachelys reveals what a primitive cryptodire would be expected to look like: a combination of primitive and derived characters, with the fewer derived characters providing the best test of its relationships to other turtles. Although incompletely known, the Mid-Late Jurassic Condorchelys, Heckeremys, and Eileanchelys may be early cryptodires close to Kayentachelys. We confirm the Late Triassic Proterochersis as a pleurodire, dating the pleurodire,cryptodire split as Late Triassic or earlier. [source] Fluorescence and coloration of grey hairINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 5 2009S. Daly Synopsis Grey hair samples were collected from 11 individuals and separated into un-pigmented and pigmented fibres (International Hair Importers). Fluorescence measurements were obtained by using a double-grating fluorescence spectrophotometer and a bifurcated fibre optics accessory to measure the spectra directly from the surface of hair at various distances from the fibre root. Colour measurements were carried out by using a Hunter colorimeter. The fluorescence spectra of un-pigmented hair obtained by the excitation at 290 nm show a peak at 356 nm [tryptophan (Trp)], and multi-peak emissions in the range from 395 to 500 nm. A significant variation in the Trp emission intensity at 356 nm vs. the intensity of emission in the 395,500 nm range was observed for hair collected from various individuals with yellow coloured hair producing stronger relative emission in 395,500 nm range. Quantitative measurements of coloration and the calculation of the Yellowness Index (YI) showed linear correlation between YI and the ratio of fluorescence intensities I440/I356 The spectra obtained by excitation at 320 nm showed the emission peaks at 395 nm (unidentified), 420 nm (N -formylkynurenine), 460 nm (kynurenine), and 495 nm (3-hydroxykynurenine), which are the products of oxidative or metabolic conversion of tryptophan. Un-pigmented, yellow hair showed a build-up of the fluorescence band corresponding to 3-hydroxykynurenine at 495 nm. The data also showed the fluorescence quenching effect of melanin resulting in the lowering of the fluorescence intensity of pigmented hair. The spectra obtained at various positions along the fibres demonstrated gradual photo-decomposition of hair chromophores during their lifetimes. This was indicated by a decrease of Trp fluorescence intensity, which was relatively fast (8·10,4,1.5·10,3 [day,1] as calculated for hair obtained from various individuals) for un-pigmented hair and slower for pigmented hair. A decrease in Trp emission was accompanied by an increase in the yellow coloration toward the ends of un-pigmented fibres. Resume Des échantillons de cheveux gris ont été collectés chez onze personnes et triés entre fibres non pigmentés et fibres pigmentés (International Hair Importers). Les mesures de fluorescence ont été réalisées à l'aide d'un spectrophotomètre de fluorescence double grille et d'un accessoire constitué d'une fibre optique bifurquée. Ce dispositif permet la mesure du spectre directement depuis la surface d'un cheveu à diverses distances de sa racine. Les mesures de couleur ont été réalisées à l'aide d'un colorimètre HUNTER. Le spectre de fluorescence d'un cheveu non pigmenté obtenu par excitation à 290 nm montre un pic à 356 nm (tryptophane : Trp) et des émissions multi pics dans l'intervalle 395 à 500 nm. On observe une variation significative de l'intensité du Trp à 356 nm par rapport à l'intensité d'émission dans l'intervalle 395,500 nm sur les cheveux prélevés sur diverses personnes, les cheveux colorés en jaune produisant une émission relative plus forte dans l'intervalle 395,500 nm. Les mesures quantitatives de la couleur et le calcul de l'indice de jaunissement (YI) montrent une corrélation linéaire entre YI et le rapport des intensités de fluorescence I 440/I356. Le spectre obtenu par excitation à 320 nm montre des pics d'émission à 395 nm (non identifiés), 420 nm (N-formylkynurenine), 460 nm (kynurenine), 495 nm (3-hydroxy kinurenine) propres aux produits d'oxydation ou de conversion métabolique du Tryptophane. Les cheveux jaunes non pigmentés présentent une saturation de la bande de fluorescence correspondant à la 3-hydroxykynurenine à 495 nm. Ces données montrent également l'effet de quenching de la mélanine entraînant un affaiblissement de l'intensité de la fluorescence des cheveux pigmentés. Le spectre obtenu en divers endroits le long des fibres indique une photodécomposition graduelle des chromophores des cheveux durant leur temps de vie. Ceci se traduit par une diminution de l'intensité de fluorescence du Trp qui est relativement rapide pour les cheveux non pigmentés (8,10,4,1,5,10,3 [jour , 1], conformément aux calculs effectués sur des cheveux prélevés sur différents individus) et par une diminution plus lente pour les cheveux pigmentés. Une diminution de l'émission du Trp s'accompagne d'une augmentation de la coloration jaune de l'extrémité des cheveux, détectable sur des cheveux non pigmentés. [source] Tellurium-Based Polymeric Surfactants as a Novel Seleno-Enzyme Model with High ActivityMACROMOLECULAR RAPID COMMUNICATIONS, Issue 24 2006Xin Huang Abstract Summary: A tellurium-based polymeric sufactant as a seleno-enzyme model has been constructed by employing 11-acryloyloxyundecyltriethylammonium bromide (AUTEAB, 4) and a tellurium-containing compound (1). It demonstrates strong substrate binding ability for thiols and high glutathione peroxidase (GPx) activity about 6 orders of magnitude more efficient than the well-known GPx mimic PhSeSePh in an ArSH assay system. More importantly, a series of tellurium-based polymeric micelle catalysts with the catalytic tellurium center located at various positions in the micelle have been constructed, and the dramatic difference in activity indicates that the exact match of the catalytic center and binding site plays a key role in enzyme catalytic efficiency. Schematic representation of the proposed mode of the telluro-micelle catalysts. [source] An Interview with Diego GambettaOXONOMICS, Issue 2 2009Article first published online: 18 DEC 200 Diego Gambetta is Professor of Sociology and official fellow at Nuffield College, University of Oxford. Born in Turin, Italy, he received his PhD in Social and Political Sciences from the University of Cambridge, U.K. in 1983. Since 1992 he has been in Oxford in various positions. He has been visiting professor at the University of Chicago, Columbia University, Science Po and the College de France in Paris. His main scholarly interests are trust, signalling theory and its applications, organised crime, and violent extremists. In 2000 he was made a Fellow of the British Academy. He is the author of numerous books including The Sicilian Mafia (Gambetta, 1993), Making Sense of Suicide Missions (Gambetta, 2005) and, most recently, The Codes of the Underworld (Gambetta, 2009). [source] Variation in fruit- and seed set among and within inflorescences of Melampyrum roseum var. japonicum (Scrophulariaceae)PLANT SPECIES BIOLOGY, Issue 1 2002Kayako Hiei Abstract Variations in fruit set and seed set among and within inflorescences of the annual herb, Melampyrum roseum var. japonicum, were studied. Under natural conditions, although the mean fruit set was slightly different among inflorescences, the mean seedset was not significantly different among inflorescences within the plants. In constrast, within the inflorescences, the flowers located at a lower position of the inflorescence and which opened earlier showed higher fruit set than those at a higher position and which opened later. However, the seed set of matured capsules were not significantly different from each other, regardless of the position of flowers within the inflorescences. Patterns of the fruit- and seed set under open pollination indicated that variation in seed reproduction of M. roseum is due to variation in fruit production. The results of clipping experiments of flowers revealed that there was no functional limitation in seed production among flowers located at various positions within the inflorescence. It seemed that the variation in the fruit set within the inflorescences of M. roseum was not attributable to ,architectural effects'. Reduction of the number of flowers within the inflorescences resulted in an increase of fruit set and seed weight, indicating that the flowers in an inflorescence compete for resources. This phenomenon supports the ,resource competition hypothesis', and variation in fruit set within the inflorescence is attributable to competition among flowers within the inflorescence for limited resources. Consequently, it was concluded that, under natural conditions, the early blooming flowers located at lower positions of the inflorescences obtain more resources and produce more fruits than the late blooming flowers located at higher positions in M. roseum. [source] Model peptide-based system used for the investigation of metal ions binding to histidine-containing polypeptidesBIOPOLYMERS, Issue 6 2010Manuela Murariu Abstract The reaction of histidine-containing polypeptides with toxic and essential metals and the molecular mechanism of complexation has yet to be determined, particularly with respect to the conformational changes of the interacting macromolecules. Therefore, a system of oligopeptides containing histidine residues in various positions of Ala or Gly sequences has been designed and used in heavy metal comparatively binding experiments. The role of spacing residues (Gly and Ala repeats) in selecting the various conformations was investigated. The newly synthesized peptides and metal ion adducts have been characterized by Fourier transform infrared spectroscopy (FTIR) as well as electrospray ion trap mass spectrometry (ESI,MS) and circular dichroism (CD). The analysis of CD-spectra of the four peptides in water revealed that the secondary structure depends much on the position of each amino acid in the peptide backbone. Our peptides system reveals various binding mechanisms of metal ions to peptides depending on the position of histidine residue and the corresponding conformations of Ala or Gly sequences. Biological and medical consequences of conformational changes of metal-bound peptides are further discussed. Thus, the binding of heavy metals to four peptides may serve as a model system with respect to the conformational consequences of the metal addition on the amino acid repeats situated in prion protein. © 2010 Wiley Periodicals, Inc. Biopolymers 93:497,508, 2010. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Commercial Hospital Discharge Packs for Breastfeeding WomenBIRTH, Issue 1 2001J. K. Gupta A substantive amendment to this systematic review was last made on 23 March 1999. Cochrane reviews are regularly checked and updated if necessary. ABSTRACT Background: For centuries, there has been controversy around whether being upright (sitting, birthing stools, chairs, squatting) or lying down has advantages for women delivering their babies. Objectives: The objective of this review was to assess the benefits and risks of the use of different positions during the second stage of labour (i.e., from full dilatation of the cervix). Search strategy: Relevant trials are identified from the register of trials maintained by the Cochrane Pregnancy and Childbirth Group, and from the Cochrane Controlled Trials Register. Selection criteria: Trials were included which compared various positions assumed by pregnant women during the second stage of labour. Randomised and quasi-randomised trials with appropriate follow-up were included. Data collection and analysis: Trials were independently assessed for inclusion, and data extracted by the two authors. Disagreements would have been resolved by consensus with an editor. Meta-analysis of data is performed using the RevMan software. Main results: Results should be interpreted with caution as the methodological quality of the 18 trials was variable. Use of any upright or lateral position, compared with supine or lithotomy positions, was associated with: 1Reduced duration of second stage of labour (12 trials,mean 5.4 minutes, 95% confidence interval (CI) 3.9,6.9 minutes). This was largely due to a considerable reduction in women allocated to use of the birth cushion. 2A small reduction in assisted deliveries (17 trials,odds ratio (OR) 0.82, 95% CI 0.69,0.98). 3A reduction in episiotomies (11 trials,OR 0.73, 95% CI 0.64,0.84). 4A smaller increase in second degree perineal tears (10 trials,OR 1.30, 95% CI 1.09,1.54). 5Increased estimated risk of blood loss > 500ml (10 trials,OR 1.76, 95% CI 1.34,3.32). 6Reduced reporting of severe pain during second stage of labour (1 trial,OR 0.59, 95% CI 0.41,0.83). 7Fewer abnormal fetal heart rate patterns (1 trial,OR 0.31, 95% CI 0.11,0.91). Reviewers' conclusions: The tentative findings of this review suggest several possible benefits for upright posture, with the possibility of increased risk of blood loss > 500 mL. Women should be encouraged to give birth in the position they find most comfortable. Until such time the benefits and risks of various delivery positions are estimated with greater certainty when methodologically stringent trials data are available, then women should be allowed to make informed choices about the birth positions in which they might wish to assume for delivery of their babies. Citation: Gupta JK, Nikodem VC. Women's position during second stage of labour (Cochrane Review). In: The Cochrane Library, Issue 4, 2000. Oxford: Update Software. [source] 40Ar/39Ar Dating of Xuebaoding Granite in the Songpan-Garzê Orogenic Belt, Southwest China, and its Geological SignificanceACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2010Yan LIU Abstract: Thus far, our understanding of the emplacement of Xuebaoding granite and the occurrence and evolution of the Songpan-Garzê Orogenic Belt has been complicated by differing age spectra results. Therefore, in this study, the 40Ar/39Ar and sensitive high resolution ion micro-probe (SHRIMP) U-Pb dating methods were both used and the results compared, particularly with respect to dating data for Pankou and Pukouling granites from Xuebaoding, to establish ages that are close to the real emplacements. The results of SHRIMP U-Pb dating for zircon showed a high amount of U, but a very low value for Th/U. The high U amount, coupled with characteristics of inclusions in zircons, indicates that Xuebaoding granites are not suitable for U-Pb dating. Therefore, muscovite in the same granite samples was selected for 40Ar/39Ar dating. The 40Ar/39Ar age spectrum obtained on bulk muscovite from Pukouling granite in the Xuebaoding, gave a plateau age of 200.1±1.2 Ma and an inverse isochron age of 200.6±1.2 Ma. The 40Ar/39Ar age spectrum obtained on bulk muscovite from Pankou granite in the Xuebaoding gave another plateau age of 193.4± 1.1 Ma and an inverse isochron age of 193.7±1.1 Ma. The 40Ar/39Ar intercept of 277.0±23.4 (2,) was very close to the air ratio, indicating that no apparent excess argon contamination was present These age dating spectra indicate that both granites were emplaced at 200.6±1.3 Ma and 193.7±1.1 Ma, respectively. Through comparison of both dating methods and their results, we can conclude that it is feasible that the muscovite in the granite bearing high U could be used for 40Ar/39Ar dating without extra Ar. Based on this evidence, as well as the geological characteristics of the Xuebaoding W-Sn-Be deposit and petrology of granites, it can be concluded that the material origin of the Xuebaoding W-Sn-Be deposit might partially originate from the Xuebaoding granite group emplacement at about 200 Ma. Moreover, compared with other granites and deposits distributed in various positions in the Songpan-Garzê Orogenic Belt, the Xuebaoding emplacement ages further show that the main rare metal deposits and granites in peripheral regions occurred earlier than those in the inner Songpan-Garzê. Therefore, 40Ar/39Ar dating of Xuebaoding granite will lay a solid foundation for studying the occurrence and evolution of granite and rare earth element deposits in the Songpan-Garzê Orogenic Belt. [source] ChemInform Abstract: One-Pot Synthesis of Novel Poly-Substituted Phenanthrenes.CHEMINFORM, Issue 32 2010Rodrigue Yougnia Abstract A one-pot Suzuki,Miyaura cross-coupling/Dieckmann,Thorpe ring closure protocol under microwave irradiation allows the introduction of diversity on various positions of the phenanthrene ring system. [source] | ||||||||||||||||