bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of ethnicity and sex on the growth of the axial and appendicular skeleton of children living in a developing country
Authors: Nyati Lukhanyo H. , Norris Shane A. , Cameron Noel , Pettifor John M. 
Published: December 2005

AbstractBones in the axial and appendicular skeletons exhibit heterogeneous growth patterns between different ethnic and sex groups. However, the influence of this differential growth on the expression of bone mineral content is not yet established. The aims of the present study were to investigate: 1) whether there are ethnic and sex differences in axial and appendicular dimensions of South African children; and 2) whether regional segment length is a better predictor of bone mass than stature. Anthropometric measurements of stature, weight, sitting height, and limb lengths were taken on 368 black and white, male and female 9‐year‐old children. DXA (dual‐energy x‐ray absorptiometry) scans of the distal ulna, distal radius, and hip and lumbar spine were also obtained. Analyses of covariance were performed to assess differences in limb lengths, adjusted for differences in stature. Multiple regression analyses were used to assess significant predictors of site‐specific bone mass. Stature‐adjusted means of limb lengths show that black boys have longer legs and humeri but shorter trunks than white boys. In addition, black children have longer forearms than white children, and girls have longer thighs than boys. The regression analysis demonstrated that site‐specific bone mass was more strongly associated with regional segment length than stature, but this had little effect on the overall pattern of ethnic and sex differences. In conclusion, there is a differential effect of ethnicity and sex on the growth of the axial and appendicular skeletons, and regional segment length is a better predictor of site‐specific bone mass than stature. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Cranial ontogeny of Papio baboons (Papio hamadryas)
Authors: Leigh Steven R. 
Published: December 2005

AbstractCranial form in subspecies of Papio baboons (Papio hamadryas) varies in relation to size, geography, and sex. However, knowledge about this variation is based mainly on adults, precluding direct assessments of the evolutionary factors that are ultimately responsible for adult shape variation. Consequently, this study tests hypotheses about the development of size and shape differences among subspecies of Papio baboons, anticipating limited evolutionary divergences in the ontogenetic pathways leading to adult endpoints. Geometric morphometric and bivariate allometric analyses are used to explore developmental size and shape variation. Allometric scaling in adult Papio baboons occurs because both sexes and all subspecies follow similar developmental pathways to a variety of adult forms. However, complex allometry contributes to form differences, producing potentially important shape differences that emerge during development. Modest shape differences that are statistically independent of size distinguish chacma baboons (P. h. ursinus) from other forms. A small‐headed subspecies, the Kinda baboon (P. h. kindae), also presents a distinctive ontogeny, and may provide insights into the evolution of size change in this species. Variation among subspecies that is statistically independent of size involves the rostrum, zygomatic breadths, and cranial flexion. These features may be related to diet, but the precise biomechanical correlates of baboon form variation remain unclear. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Phylogenetic analyses of dimorphism in primates: Evidence for stronger selection on canine size than on body size
Authors: Thorén Sandra , Lindenfors Patrik , Kappeler Peter M. 
Published: December 2005

AbstractPhylogenetic comparative methods were used to analyze the consequences of sexual selection on canine size and canine size dimorphism in primates. Our analyses of previously published body mass and canine size data revealed that the degree of sexual selection is correlated with canine size dimorphism, as well as with canine size in both sexes, in haplorhine but not in strepsirrhine primates. Consistent with these results, male and female canine size was found to be highly correlated in all primates. Since canine dimorphism and canine size in both sexes in haplorhines were found to be not only related to mating system but also to body size and body size dimorphism (characters which are also subject to or the result of sexual selection), it was not apparent whether the degree of canine dimorphism is the result of sexual selection on canine size itself, or whether canine dimorphism is instead a consequence of selection on body size, or vice versa. To distinguish among these possibilities, we conducted matched‐pairs analyses on canine size after correcting for the effects of body size. These tests revealed significant effects of sexual selection on relative canine size, indicating that canine size is more important in haplorhine male‐male competition than body size. Further analyses showed, however, that it was not possible to detect any evolutionary lag between canine size and body size, or between canine size dimorphism and body size dimorphism. Additional support for the notion of special selection on canine size consisted of allometric relationships in haplorhines between canine size and canine size dimorphism in males, as well as between canine size dimorphism and body size dimorphism. In conclusion, these analyses revealed that the effects of sexual selection on canine size are stronger than those on body size, perhaps indicating that canines are more important than body size in haplorhine male‐male competition. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Synthesis and photophysical properties of novel amphiphilic ruthenium (II) complexes containing 4,4′‐dialkylaminomethyl‐2,2′‐bipyridyl ligands
Authors: Kirilov Plamen , Matondo Hubert , Vicendo Patricia , Garrigues Jean‐Christophe , Baboulène Michel , Nguyen Hoang‐Phuong , Rico‐Lattes Isabelle 
Published: December 2005

AbstractThe synthesis of a number of new 2,2′‐bipyridine ligands functionalized with bulky amino side groups is reported. Three homoleptic polypyridyl ruthenium (II) complexes, [Ru(L)3]2+ 2(PF6−), where L is 4,4′‐dioctylaminomethyl‐2,2′‐bipyridine (Ru4a), 4,4′‐didodecylaminomethyl‐2,2′‐bipyridine (Ru4b) and 4,4′‐dioctadodecylaminomethyl‐2,2′‐bipyridine (Ru4c), have been synthesized. These compounds were characterized and their photophysical properties examined. The electronic spectra of three complexes show pyridyl π → π* transitions in the UV region and metal‐to‐ligand charge transfer bands in the visible region. Copyright © 2005 John Wiley & Sons, Ltd.
Ethylene and propylene polymerization by the new substituted bridged (cyclopentadienyl)(fluorenyl) zirconocenes
Authors: Yang Xiaoxia , Zhang Yong , Huang Jiling 
Published: December 2005

AbstractEight Cs‐symmetric complexes, R1R2C(Cp)(Flu)MCl2 [R1 = R2 = CH3CH2CH2, M = Zr (1), Hf (2); R1 = R2 = pCH3OC6H4, M = Zr (3), Hf (4); R1 = ptBuC6H4, R2 = Ph, M = Zr (5), Hf (6); R1 = R2 = ptBuC6H4, M = Zr (7); R1 = R2 = PhCH2, M = Zr (8)] have been synthesized and characterized. Zirconocenes all showed the same high catalytic activities in ethylene polymerization as complex Ph2C(Cp)(Flu)ZrCl2 (9). However, in the propylene polymerization, the catalytic activities decreased in the order 5 ≈ 9 > 7 > 8. Introduction of tBu decreased the activities, probably due to the bulk steric hindrance. The polypropylene produced by 5 and 7 with tBu substituent showed a higher molecular weight (Mη) than that produced by 9. The 13C NMR spectrum revealed the polymers from 7 and 8 to have shorter average syndiotactic block length than polymer produced by 9. It was noted that [mm] stereodefect of polypropylene by 8 could not be observed from 13C NMR, which showed that the benzyl on bridge carbon 8 prevented chain epimerization and enatiofacial misinsertion in polymerization. Copyright © 2005 John Wiley & Sons, Ltd.
Preparation, spectral characterization, electrochemistry, EXAFS, antibacterial and catalytic activity of new ruthenium (III) complexes containing ONS donor ligands with triphenylphosphine/arsine
Authors: Prabhakaran R. , Krishnan V. , Pasumpon K. , Sukanya D. , Wendel E. , Jayabalakrishnan C. , Bertagnolli H. , Natarajan K. 
Published: December 2005

AbstractNew hexa‐coordinated ruthenium (III) complexes of the type [RuX(EPh3)2(L)] (X = Cl or Br; L = dibasic tridentate Schiff base ligand; E = P or As) have been synthesized by the reactions of [RuCl3(PPh3)3], [RuCl3(AsPh3)3] or [RuBr3(AsPh3)3] with the appropriate Schiff base ligands derived by the condensation of salicylaldehyde and 2‐hydroxy‐1‐naphthaldehyde with N(4) substituted thiosemicarbazones. All the new complexes were characterized using various physico‐chemical methods such as elemental analyses, infrared, electron paramagnetic resonance (EPR) spectroscopy, magnetic moment and cyclic voltammetry. Based on the extended X‐ray absorption fine structure (EXAFS) analysis, an octahedral structure has been confirmed for the complexes. The new complexes have been subjected to the catalytic activity and antibacterial studies. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis, structure and ethylene polymerization of group 4 complexes with phosphinoamide ligands
Authors: Qi Changhe , Zhang Suobo , Sun Jinghun 
Published: December 2005

AbstractGroup 4 complexes containing diphosphinoamide ligands [Ph2PNR]2MCl2 (3: R = tBu, M = Ti; 4: R = tBu, M = Zr; 5: R = Ph, M = Ti; 6: R = Ph, M = Zr) were prepared by the reaction of MCl4 (M = Ti; Zr) with the corresponding lithium phosphinoamides in ether or THF. The structure of [Ph2PNtBu]2TiCl2 (3) was determined by X‐ray crystallography. The phosphinoamides functioned as η2‐coordination ligands in the solid state and the TiN bond length suggests it is a simple single bond. In the presence of modified methylaluminoxane or i‐Bu3Al/Ph3BC(C6F5)4, catalytic activity of up to 59.5 kg PE/mol cat h bar was observed. Copyright © 2005 John Wiley & Sons, Ltd.
Morphology and DNA degeneration during autoschizic cell death in bladder carcinoma T24 cells induced by ascorbate and menadione treatment
Authors: Gilloteaux Jacques , Jamison James M. , Arnold David , Neal Deborah R. , Summers Jack L. 
Published: December 2005

AbstractFeulgen and actin‐phalloidin staining as well as gel electrophoresis have been employed in conjunction with cell ultrastructure to describe the effects of 1‐, 2‐, and 4‐hr ascorbate (VC), menadione (VK3), and ascorbate:menadione (VC:VK3) treatments on the T24 human bladder carcinoma cell line. T24 cells exposed to VC alone display blebs and other superficial membrane defects related to membrane alterations and to superficial cytoskeleton changes. VK3 treatment damages the cell nucleus and organelles, leads to the redistribution of the organelles in the perikaryon as a consequence of cytoskeletal damage, and results in cytoplasmic self‐excisions. After VC:VK3 treatment, the cells show exaggerated alterations characteristic of each vitamin treatment alone, including damaged mitochondria, self‐excision of organelle‐free pieces of cytoplasm, and extrusion of the perikaryon containing a nucleus surrounded by the damaged organelles. The nuclear envelope appears intact and contains chromatin that decondenses and dissipates. During the cellular demise that concludes with apparent karyolysis, the cells significantly decrease their size and alter their shape. However, the cisterns of rough endoplasmic reticulum are undamaged, but may become dilated. Since the cellular phenomena leading to cell death differ morphologically from apoptosis and necrosis, but entail self‐cutting without nuclear bodies, this new form of cell death was called autoschizis. In addition, gel electrophoresis and Feulgen staining demonstrate that autoschizis is accompanied by random DNA degeneration. © 2005 Wiley‐Liss, Inc.
L and T brown dwarfs in the Ursa Major moving group
Authors: Bannister N. P. , Jameson R. F. 
Published: December 2005

AbstractWe have applied the “moving cluster” method to an archive of L and T brown dwarf stars to identify those stars which are members of the Ursa Major moving group.We show that five stars have proper motion directions which agree with the direction of motion expected for a cluster member, and which have proper motion distances in agreement with distances determined by trigonometrical parallax observations. We then use 2MASS data to produce an M K versus J ‐ K S colour magnitude diagram. The group members define an empirical 400 Myr isochrone, which is compared to theoretical models. This is the first cluster/group to have a known T dwarf member. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Widely separated binary systems of very low‐mass stars
Authors: Phan‐Bao N. , Martín E. L. , Reylé C. , Forveille T. , Lim J. 
Published: December 2005

AbstractIn this paper we review some recent detections of wide binary brown dwarf systems and discuss them in the context of the multiplicity properties of very low‐mass stars and brown dwarfs. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Calibrating models of ultralow‐mass stars
Authors: Reiners A. 
Published: December 2005

AbstractEvolutionary and atmospheric models have become available for young ultralow‐mass objects. These models are being used to determine fundamental parameters from observational properties. TiO bands are used to determine effective temperatures in ultralow‐mass objects, and together with Na‐ and K‐lines to derive gravities at the substellar boundary. Unfortunately, model calibrations in (young) ultralow‐mass objects are rare. As a first step towards a calibration of synthetic spectral features, I show molecular bands of TiO, which is a main opacity source in late M‐dwarfs. The TiO ε ‐band at 8450 Å is systematically too weak. This implies that temperatures determined from that band are underestimated, and I discuss implications for determining fundamental parameters from high resolution spectra. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low mass companions to white dwarfs
Authors: Farihi J. , Zuckerman B. , Becklin E. E. 
Published: December 2005

AbstractThis paper summarizes the results of over 17 years of work searching for low mass stellar and substellar companions to more than 370 nearby white dwarfs. Roughly 60 low mass, unevolved companions were found and studied all together, with over 20 discovered in the last few years, including the first unambiguous brown dwarf companion to a white dwarf, GD 1400B. The resulting spectral type distributions for companions to white dwarfs and nearby cool field dwarfs are compared, and the implications for binary star formation are discussed. A brief analysis of GD 1400B, including new data, is also presented. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interactions between hot Jupiters and their host stars
Authors: Gu Pin‐Gao , Shkolnik E. , Li Shu‐Lin , Liu Xiao‐Wei 
Published: December 2005

AbstractA young hot Jupiter might have been tidally inflated beyond its Roche radius when its orbit was being circularized. This scenario has the potential to explain a couple of solid or tentative observations such as a pile‐up of hot Jupiters around 0.04‐0.05 AU, the mass‐period correlation of transiting planets, as well as the existence of hot Neptunes. Other scenarios such as tidal dissipation in a planet‐host star as well as the magnetic interaction will be also discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
VISIR/VLT observations of brown dwarfs in Upper Scorpius
Authors: Huélamo N. , Bouy H. , Sterzik M. , Pantin E. , MartÍn E.L. 
Published: December 2005

AbstractWe present mid‐IR observations of a sample of very low‐mass stars and brown dwarfs in the Upper Scorpius association. The main goal of these observations is to derive the disk frequency and the disk properties of the sample in order to shed light on brown dwarf formation theories. The observations have been performed with VISIR at the Very Large Telescope (VLT, Paranal). A total of ten targets were observed and six were detected. In this paper we show preliminary results for two of them: DENIS‐PJ160334 and DENIS‐PJ161939. While the former shows mid‐IR fluxes consistent with pure photospheric emission, the latter displays strong mid‐IR excesses which are probably related with a circumstellar disk. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AB Doradus C: age, spectral type, orbit, and comparison to evolutionary models
Authors: Nielsen E. L. , Close L. M. , Guirado J. C. , Biller B. A. , Lenzen R. , Brandner W. , Hartung M. , Lidman C. 
Published: December 2005

AbstractWe expand upon the results of Close et al. (2005) regarding the young, low‐mass object AB Dor C and its role as a calibration point for theoretical tracks. We present an improved spectral reduction and a new orbital solution with two additional epochs. Our improved analysis confirms our spectral type of M8 (±1) and mass of 0.090 ± 0.003 M⊙ for AB Dor C. Comparing the results for AB Dor C with other young, low‐mass objects with dynamical masses we find a general trend where current evolutionary models tend to over‐predict the temperature (or under‐predict the mass) for low‐mass stars and brown dwarfs. Given our precision, there is a ∼99% chance that the mass of AB Dor C is underestimated by the DUSTY tracks in the HR diagram. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variability in the Lambda Orionis cluster substellar domain
Authors: Barrado Y Navascués D. , Huélamo N. , Morales Calderón M. 
Published: December 2005

AbstractWe present the first results on variability of very low mass stars and brown dwarfs belonging to the ∼5 Myr Lambda Orionis cluster (Collinder 69). We have monitored almost continuously in the J filter a small area of the cluster which includes 12 possible members of the cluster during one night. Some members have turned to be short‐term variables. One of them, LOri167, has a mass close to the planetary mass limit and its variability might be due to instabilities produced by the deuterium burning, although other mechanism cannot be ruled out. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A coronagraphic search for brown dwarfs and planets around nearby stars
Authors: Nakajima T. , Morino J.‐I. , Tsuji T. , Suto H. , Ishii M. , Tamura M. , Fukagawa M. , Murakawa K. , Miyama S. , Takami H. , Takato N. , Oya S. , Hayashi S. , Kudo T. , Itoh Y. , Oasa Y. , Oppenheimer B. R. 
Published: December 2005

AbstractWe have started a corongraphic search for brown dwarfs and planets around young nearby stars within 20 pc of the Sun, using the adaptive optics coronagraph, CIAO, on Subaru. The dynamic range we have achieved is ΔK = 13 at 2.5″ from the central star. For a typical target with K = 7 at 10 pc, the limiting absolute magnitude is MK = 20. We apply two kinematical age criteria to select M and K dwarfs statistically younger than 350Myr. The first criterion is a small velocity deviation from the velocity of LSR. The second is a (U, V,W ) velocity vector similar to a particular young moving group. The combination of the age and magnitude limits implies that the mass limit for giant planet detection is about 2 MJ. We show a sample image of a target field at 3 pc of the Sun with faint companion candidates, to be followed up for the common proper motion test. We give a brief description of our procedures for data acquisition, reduction, and analysis. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The formation of brown dwarfs
Authors: Whitworth A. P. , Goodwin S.P. 
Published: December 2005

AbstractWe review four mechanisms for forming brown dwarfs: (i) turbulent fragmentation (producing very low‐mass prestellar cores); (ii) gravitational instabilities in discs; (iii) dynamical ejection of stellar embryos from their placental cores; and (iv) photo‐erosion of pre‐existing cores in HII regions. We argue (a) that these are simply the mechanisms of low‐mass star formation , and (b) that they are not mutually exclusive. If, as seems possible, all four mechanisms operate in nature, their relative importance may eventually be constrained by their ability to reproduce the binary statistics of brown dwarfs, but this will require fully 3‐D radiative magneto‐hydrodynamic simulations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Using near‐IR spectroscopy to classify substellar candidates in the Trapezium Cluster
Authors: Meeus G. , McCaughrean M. J. 
Published: December 2005

AbstractWe discuss the use of near‐IR spectroscopy to confirm young substellar candidates that were selected by photometry. We first review near‐IR spectroscopic methods used to classify young brown dwarf candidates. In a subsequent part, we present ISAAC/VLT photometric and spectroscopic data of substellar candidates in the Trapezium Cluster. These data will be used to derive the effective temperature and reddening of the objects. We create a grid of synthetic spectra from Allard et al. (2000) with different degrees of reddening and compare those with our spectra, assuming a gravity of log g = [3.5, 4.0], which is typical for young objects. The best fitting reddened synthetic spectrum gives us the most likely effective temperature and extinction for our sources. Next, we compare the temperature derived from dereddening the objects towards a 1 Myr isochrone in a colour‐magnitude diagram with the one obtained by fitting synthetic atmosphere models to the spectra, and show what extend the differences have when deriving the masses of the objects (under the assumption of an age of 1 Myr). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Convective radiation fluid‐dynamics: formation and early evolution of ultra low‐mass objects
Authors: Wuchterl G. 
Published: December 2005

AbstractThe formation process of ultra low‐mass objects is some kind of extension of the star formation process. The physical changes towards lower mass are discussed by investigating the collapse of cloud cores that are modelled as Bonnor‐Ebert spheres. Their collapse is followed by solving the equations of fluid dynamics with radiation and a model of time‐dependent convection that has been calibrated to the Sun. For a sequence of cloud‐cores with 1 to 0.01 solar masses, evolutionary tracks and isochrones are shown in the mass‐radius diagram, the Hertzsprung‐Russel diagram and the effective temperaturesurface gravity or Kiel diagram. The collapse and the early hydrostatic evolution to ages of few Ma are briefly discussed and compared to observations of objects in Upper Scorpius and the low‐mass components of GG Tau. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Accretion in brown dwarfs down to nearly planetary masses
Authors: Mohanty S. , Basri G. , Jayawardhana R. 
Published: December 2005

AbstractWe show that in accreting ultra low‐mass stars and brown dwarfs, the CaII λ 8662 emission line flux correlates remarkably well with the mass accretion rate ($ \dot M $), just as it does in higher mass classical T Tauri stars (CTTs). A straightforward measurement of the CaII flux thus provides an easier $ \dot M $ determination technique than detailed modeling of the Hα emission line profile (except at the very lowest accretion rates, where CaII does not appear to be in emission for ultra low‐mass objects, and Hα modeling is required). Using optical high‐resolution spectra, we infer $ \dot M $ from CaII emission for young ultra low‐mass objects down to nearly the deuterium‐burning (planetary‐mass) limit. Our results, in combination with previous determinations of $ \dot M $ in CTTs, illustrate that the accretion rate declines steeply with mass, roughly as $ \dot M $ ∝ M*2 (albeit with considerable scatter). A similar relationship has been suggested by previous studies; we extend it down to nearly the planetary regime. The physical reason for this phenomenon is not yet clear; we discuss various possible mechanisms. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)