bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic biaxial strain affects U937 macrophage‐like morphology and enzymatic activities
Authors: Matheson Loren A. , Maksym Geoffrey N. , Santerre J. Paul , Labow Rosalind S. 
Published: October 2005

AbstractAs monocytes migrate to the site of a foreign body and differentiate into mature monocyte‐derived macrophages (MDMs), the cells undergo a morphological transformation that involves mechanical stimulation via membrane stretch. Because the site of many cardiovascular implant devices includes substrates that are also undergoing mechanical change, it is of interest to assess the effect of such dynamic conditions on cellular–biomaterial responses. This study investigated the influence of cyclic (0.25 Hz) biaxial strain (maximum 10% amplitude) on human U937 macrophage‐like cells cultured on a flexible siloxane membrane. Cell attachment was unaffected by the strain but total protein levels were significantly higher in stimulated cells. Intracellular esterase and released acid phosphatase activities were elevated by dynamic loading in addition to a strain‐induced increase of monocyte‐specific esterase protein as demonstrated by immunoblotting analysis. The morphology of static cells changed with cyclic strain from a round cell shape to an irregular, spread phenotype with a progressive reorganization of filamentous actin. The focal adhesion protein vinculin showed distinct reorganization in structure going from a well‐defined arrangement in static cells to a diffuse staining pattern in mechano‐stimulated cells. This study has demonstrated that U937 cells respond to cyclic deformation with an augmentation of select enzymatic activities that have been identified as being important in polymer biodegradation processes, as well as morphological changes, which may be characteristic of mechanical stress‐induced cell activation. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
In vitro bioactivity of akermanite ceramics
Authors: Wu Chengtie , Chang Jiang , Ni Siyu , Wang Junying 
Published: October 2005

AbstractIn this study, the bone‐like apatite‐formation ability of akermanite ceramics (Ca2MgSi2O7) in simulated body fluid (SBF) and the effects of ionic products from akermanite dissolution on osteoblasts and mouse fibroblasts (cell line L929) were investigated. In addition, osteoblast morphology and proliferation on the ceramics were evaluated. The results showed that akermanite ceramics possessed bone‐like apatite‐formation ability comparable with bioactive wollastonite ceramics (CaSiO3) after 20 days of soaking in SBF and the mechanism of bone‐like apatite formation on akermanite ceramics is similar to that of wollastonite ceramics. The Ca, Si, and Mg ions from akermanite dissolution at certain ranges of concentration significantly stimulated osteoblast and L929 cell proliferation. Furthermore, osteoblasts spread well on the surface of akermanite ceramics, and proliferated with increasing the culture time. The results showed that akermanite ceramics possess bone‐like apatite‐formation ability and can release soluble ionic products to stimulate cell proliferation, which indicated good bioactivity. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Synthesis and self‐catalyzed phase transfer reaction of novel methacrylate polymers
Authors: Dizman Bekir , Mathias Lon J. 
Published: October 2005

AbstractEthyl α‐chloromethylacrylate was converted to an ester derivative using 5‐chlorovaleric acid in a single step. The homopolymerization of the new monomer (CEMA) and its copolymerization with methyl methacrylate were performed using photoinitiator Irgacure 651. The polymers were reacted with N,N‐dimethyldodecylamine to obtain polymers with pendant quaternary ammonium (QA) moieties. The polymers with pendant QA groups were used in self‐catalyzed phase transfer reactions with sodium phenoxide and 1‐dodecanethiol. The syntheses of the monomer and polymers were followed by FTIR, 1H NMR, and 13C NMR. The average polymer molecular weights and polydispersities were determined by size exclusion chromatography. Thermal analysis was carried out using thermogravimetric analysis and differential scanning calorimetry. The copolymer composition, degree of quaternization, and degree of conversion in phase transfer reaction were determined by 1H NMR. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5844–5854, 2005
Isothermal frontal polymerization: Confirmation of the mechanism and determination of factors affecting the front velocity, front shape, and propagation distance with comparison to mathematical modeling
Authors: Lewis Lydia L. , DeBisschop Cynthia S. , Pojman John A. , Volpert Vladimir A. 
Published: October 2005

AbstractIsothermal frontal polymerization (IFP) is a directional polymerization that uses the Trommsdorff, or gel, effect to produce gradient materials for optical applications. When a solution of methyl methacrylate and a thermal initiator contacts a polymer seed (a small piece of polymer), a viscous region is formed in which the polymerization rate is faster because of the Trommsdorff effect. Using the optical techniques of laser line deflection (Weiner's method) and shadowgraphy along with controls, we obtained definitive experimental evidence of IFP. Moreover, we were able to measure accurately and precisely the front position and front concentration profile as a function of time by monitoring IFP systems and controls of various initiator concentrations and cure temperatures. The experimental data were compared with theoretical predictions from a model using mass‐diffusion and radical polymerization kinetics. The model reproduced the decrease of the propagation time and showed an increase in the propagation velocity for an increase in the initiator concentration and/or cure temperature. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5774–5786, 2005
Metal‐cation‐induced chiroptical switching for poly(phenylacetylene) bearing a macromolecular ionophore as a graft chain
Authors: Otsuka Issei , Sakai Ryosuke , Satoh Toshifumi , Kakuchi Ryohei , Kaga Harumi , Kakuchi Toyoji 
Published: October 2005

AbstractA poly(phenylacetylene) bearing a polycarbohydrate ionophore as a graft chain (copolymer 4) was synthesized by the copolymerization of end‐functionalized (1→6)‐2,5‐anhydro‐3,4‐di‐O‐ethyl‐D‐glucitol with a 4‐ethynylbenzoyl group (macromonomer 2) with phenylacetylene. Copolymer 4 showed a split‐type circular dichroism (CD) in the long absorption region of the conjugated polymer backbone (280–500 nm), and the CD pattern varied in response to external stimuli, such as the solvents and temperature. This suggested that 4 had a predominantly one‐handed helical conformation in the polyacetylene backbone. The CD pattern of 4 was completely inverted by the formation of a complex between the macromolecular ionophore units and the selected metal cations, that is, Ba2+, Pb2+, Sr2+, Na+, and Li+. This suggested that copolymer 4 underwent a helix–helix transition through the host–guest complexation with achiral inorganic metal cations. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5855–5863, 2005
Sensitive detection of sequence similarity using combinatorial pattern discovery: A challenging study of two distantly related protein families
Authors: Darzentas Nikos , Rigoutsos Isidore , Ouzounis Christos A. 
Published: October 2005

AbstractWe investigate the performance of combinatorial pattern discovery to detect remote sequence similarities in terms of both biological accuracy and computational efficiency for a pair of distantly related families, as a case study. The two families represent the cupredoxins and multicopper oxidases, both containing blue copper‐binding domains. These families present a challenging case due to low sequence similarity, different local structure, and variable sequence conservation at their copper‐binding active sites. In this study, we investigate a new approach for automatically identifying weak sequence similarities that is based on combinatorial pattern discovery. We compare its performance with a traditional, HMM‐based scheme and obtain estimates for sensitivity and specificity of the two approaches. Our analysis suggests that pattern discovery methods can be substantially more sensitive in detecting remote protein relationships while at the same time guaranteeing high specificity. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Structural basis for SUMO‐E2 interaction revealed by a complex model using docking approach in combination with NMR data
Authors: Ding Husheng , Yang Yuedong , Zhang Jiahai , Wu Jihui , Liu Haiyan , Shi Yunyu 
Published: October 2005

AbstractThe interaction between small ubiquitin‐related modifier SUMO and its conjugating‐enzyme Ubc9 (E2) is an essential step in SUMO conjugation cascade. However, an experimental structure of such a transient complex is still unavailable. Here, a structural model of SUMO‐3‐Ubc9 complex was obtained with HADDOCK, combining NMR chemical shift mapping information. Docking calculations were performed using SUMO‐3 and Ubc9 structures as input. The resulting complex reveals that the complementary surface electrostatic potentials contribute dominantly to the specific interaction. At the interface, similar numbers of oppositely‐charged conserved residues are identified on the respective binding partners. Hydrogen bonds are formed in the vicinity of the interface to stabilize the complex. Comparison of the structure of SUMO‐3‐Ubc9 complex generated by HADDOCK and the experimental structures in free form indicates that SUMO‐3 and Ubc9 maintain their respective fold as a whole after docking. However, the N‐terminal helix α1 and its subsequent L1 loop of Ubc9 experience sizeable changes upon complex formation. They cooperatively move towards the hydrophilic side of the β‐sheet of SUMO‐3. Our observations are consistent with the data from previous Ubc9 mutational analysis and conformational flexibility studies. Together, we have proposed that the SUMO‐3‐Ubc9 interaction is strongly electrostatically driven and the N terminus of Ubc9 shifts to SUMO‐3 to facilitate the interaction. The NMR‐based structural model, which provides considerable insights into the molecular basis of the specific SUMO‐E2 recognition and interaction, implicates the general interaction mode between SUMO‐3 and Ubc9 homologues from yeast to humans. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Density functional theory investigation of the alkylating strength of organoaluminum co‐catalysts for Ziegler–Natta polymerization
Authors: Champagne Benoît , Cavillot Valérie , André Jean‐Marie , François Philippe , Momtaz Ardéchir 
Published: October 2005

AbstractThe ability of the Et2Al–R co‐catalyst series [with R = Et, Cl, O–Me, O‐iPr, NH–Me, S–Me, and S–iPr] to alkylate titanum chloride has been evaluated at the B3LYP/6‐31G* level of approximation. The impact of dimerization and complexation by Lewis bases on their alkylating strength has been tackled. It turns out that both the dimerization and the complexation reactions increase the exothermicity of the global alkylation process. Nevertheless, these reactions can also annihilate the alkylating strength of these co‐catalysts due to the formation of highly stable species. In particular, we have found that (i) the alkylating strength of Et2Al–R co‐catalysts with R = O–R′ and NH‐R′ is weak due to the formation of very stable dimers; (ii) the alkylating strength of Et2Al–S–R′ increases upon adding Lewis bases, whereas Lewis bases make Et3Al less alkylating; and (iii) Et2Al–Cl is less affected by the presence of Lewis bases. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Trends in age-at-recruitment and juvenile growth of cuttlefish, Sepia officinalis, from the English Channel
Authors: Challier Laurence , Dunn Matthew R. , Robin Jean-Paul 
Published: October 2005

Abstract
The cuttlefish Sepia officinalis is an important fishery resource in the English Channel, and one of the largest stocks of cephalopods in the Northeast Atlantic. Cuttlefish live for approximately 2 years and catches consequently depend largely on recruitment. Early life stages were analysed for differences in juvenile growth and age-at-recruitment to the commercial fisheries. Recruits were sampled monthly between October 2000 and June 2003, and pre-recruits from the coastal waters of the UK and France in the summers of 2000 and 2002. Age (days) was determined from statoliths. Although most cuttlefish were recruited during autumn, there was some recruitment throughout the year. Age-at-recruitment varied significantly between season and cohort, but was consistently in the range 3–4 months, so although there was some hatching throughout the year, most cuttlefish hatched during summer. Fitted growth models indicated that the growth rates of pre-recruits (7–59 mm mantle length) were significantly higher in 2002 than in 2000. Spatial differences in growth rate were apparent in 2000, suggesting that pre-recruit growth may depend on local environmental conditions. Pre-recruits and recruits combined (7–106 mm mantle length) also showed significant variation in growth between hatching months and years. Hypotheses explaining the observed patterns of growth and recruitment are presented.
Seasonal population dynamics of Octopus vulgaris in the eastern Mediterranean
Authors: Katsanevakis Stelios , Verriopoulos George 
Published: October 2005

Abstract
The population density of Octopus vulgaris was measured by visual census with scuba diving in coastal areas in Greece (eastern Mediterranean). A time-variant, stage-classified, matrix population model was developed to interpret the seasonal variation of octopus stage densities and to estimate several life cycle parameters. An annual and a semi-annual periodic cycle were found in the stage densities. A main peak of benthic settlement was observed during summer and a secondary, irregular one during late autumn. Two spawning peaks were estimated, a main one during late winter–spring and a secondary one during late summer–early autumn. More than 50% of the just-settled individuals will eventually die after 3 months. Mortality rate declines, as individuals grow larger, reaches a minimum approximately 6 months after settlement, and then grows again probably because of terminal spawning. The life expectancy of recently settled individuals (<50 g) during their summer peak is approximately 5 months. The lifespan of the common octopus is estimated to be between 12 and 15 months. The octopuses' mean specific growth rates (±s.d.) in their natural environment were 1.61 ± 0.30 d−1 for 50–200 g individuals and 1.19 ± 0.31 d−1 for 200–500 g individuals.
Spatial behaviour of the rock‐dwelling pika (Ochotona hyperborea)
Authors: Gliwicz Joanna , Witczuk Julia , Pagacz Stanisław 
Published: October 2005

AbstractThe territorial behaviour and the social–spatial activity of Ochotona hyperborea during the hay‐storage season are described and a comparative analysis of Asian and American rock‐dwelling species is presented. Seven pairs of O. hyperborea held territories of c. 900 m2, used the same shelter, spent most of their time in the same core area and stored food collectively. Males and females differed in mobility, and behaviour related to defence of territory. The intercontinental comparison of the behaviour and ecology of pikas, based on these data and on published information, revealed that despite different social organization, their mating systems, life‐history parameters and population characteristics are very similar.
Foraging ecology of jaguar (Panthera onca) and puma (Puma concolor) in hunted and non‐hunted sites within the Maya Biosphere Reserve, Guatemala
Authors: Novack Anthony J. , Main Martin B. , Sunquist Melvin E. , Labisky Ronald F. 
Published: October 2005

AbstractSubsistence hunting and commercial exploitation directly influence wildlife populations in many regions of Central and South America. Where prey populations are exploited, the foraging ecology of top‐level predators can be effected negatively. This study assessed the food habits and prey selection of jaguar Panthera onca and puma Puma concolor within hunted and non‐hunted segments of the Maya Biosphere Reserve (MBR), Guatemala. Food habits were determined from analysis of 76 jaguar and 145 puma scats collected within hunted and non‐hunted areas of the MBR from February 2000 to August 2001. Diets of jaguar and puma were compared (1) within species between areas with and without hunting to evaluate effects of subsistence hunting, and (2) between species to evaluate resource partitioning between these sympatric carnivores. Origin of predator scats was determined from mitochondrial DNA, diets were determined from prey remnants found within scats, and frequency of prey in scats was compared to expected values based on prey density estimates to test the hypothesis that diets of jaguar and puma were selective. Densities of major prey species were estimated using line‐transect sampling. White‐lipped peccary Tayassu pecari, collared peccary Tayassu tajacu and brocket deer Mazama sp. were less abundant, and coatis Nasua nasua more abundant, in the hunted area than in the non‐hunted area. Jaguar and puma in both hunted and non‐hunted sites obtained similar dietary contributions from large prey to their respective diets despite differences in the abundance of these prey species. Diets of jaguar and puma, as measured by percentage biomass occurrence of prey species, did not differ between hunted and non‐hunted areas. Jaguar diets were dominated by medium‐sized prey, particularly armadillos Dasypus novemcinctus and coatis, in both hunted and non‐hunted areas. Medium‐sized mammals also were prominent in puma diets, but large mammals constituted approximately 50% of prey biomass in both hunted and non‐hunted areas. Deer Odocoileus virginianus and Mazama sp. and large rodents Agouti paca and Dasyprocta punctata were the most important prey of puma. Dietary overlap between jaguar and puma in both hunted and non‐hunted areas was low.
Natural diet and prey‐choice behaviour of Aelurillus muganicus (Araneae: Salticidae), a myrmecophagic jumping spider from Azerbaijan
Authors: Huseynov Elchin F. , Cross Fiona R. , Jackson Robert R. 
Published: October 2005

AbstractThe distinctions between a predator's diet, its prey‐choice behaviour and its preferences are illustrated in a study of Aelurillus muganicus, a salticid spider from the Apsheron Peninsula in Azerbaijan. Laboratory experiments showed that A. muganicus has an innate predisposition to choose ants as prey. The natural diet of this species was determined by sampling individuals seen feeding in the field (n= 64). Ten arthropod orders were represented. Seven were from the class Insecta (Coleoptera, Collembola, Diptera, Heteroptera, Homoptera, Hymenoptera, Lepidoptera) and three from the class Arachnida (Acari, Araneae, Pseudoscorpiones). Collectively, four orders accounted for >70% of the prey records: Hymenoptera (20%), Lepidoptera (19%), Acari (19%) and Homoptera (14%). No other order accounted for >10% of the prey records. Of the 45 insects among the prey, 13 (29%) were Hymenoptera, with ants (family Formicidae) alone accounting for 24% of the prey records. Although ants were the preferred prey of A. muganicus, as revealed by laboratory testing, and also the most common single category of prey from the field prey records, records of A. muganicus feeding on prey other than ants were actually more common than records of it feeding on ants, suggesting that, besides prey choice, other factors have a strong influence on the diet of this species.
Diet and prey selection of cormorants (Phalacrocorax carbo) at Loch Leven, a major stocked trout fishery
Authors: Stewart D. C. , Middlemas S. J. , Gardiner W. R. , Mackay S. , Armstrong J. D. 
Published: October 2005

AbstractNumbers of great cormorants Phalacrocorax carbo feeding in inland waters during winter have increased throughout Europe resulting in concerns over their impacts on fisheries. Loch Leven is a world‐renowned sport fishery for trout and supports a nationally important population of wintering cormorants. The relationships between brown trout stocking, regional cormorant numbers and cormorants counted during winter on Loch Leven were examined. Stocked brown trout were fin‐clipped before release and gut contents from a sample of 96 cormorants shot under scientific licence were analysed. The data suggest that the number of cormorants at this site is influenced by both the stocking policy and the regional population level. Cormorant diet varied with the sex and age of birds. Overall, trout made up c. 85% of the total content by weight. Brown trout predominated in the diet, making up c. 70%, while rainbow trout occurred less frequently, making up c. 6%. Trout which could not be identified to species, made up the remainder (c. 9%). There was no significant difference in the ratios of wild and stocked brown trout sampled from the loch and from cormorant stomachs in winter. A model was constructed to investigate the likely loss of trout to cormorants roosting on the loch. It was estimated that over a 7‐month period cormorants consumed 80 803 (41 617–128 248) brown and 5213 (830–12 454) rainbow trout. These estimates compared to average annual fishery catches of 5828 brown and 12 815 rainbow trout (1996–2000). Comparison with published estimates of trout populations in Loch Leven indicated a high potential for competition between the birds and the fisheries for available fish. It is suggested that stocking has led to an increase in cormorant numbers and the subsequent increase in predation may have prevented any increase in the trout population or in fishery catches.
The Paleogene fossil record of birds in Europe
Authors: Mayr Gerald 
Published: October 2005

ABSTRACTThe Paleogene (Paleocene‐Oligocene) fossil record of birds in Europe is reviewed and recent and fossil taxa are placed into a phylogenetic framework, based on published cladistic analyses. The pre‐Oligocene European avifauna is characterized by the complete absence of passeriform birds, which today are the most diverse and abundant avian taxon. Representatives of small non‐passeriform perching birds thus probably had similar ecological niches before the Oligocene to those filled by modern passerines. The occurrence of passerines towards the Lower Oligocene appears to have had a major impact on these birds, and the surviving crown‐group members of many small arboreal Eocene taxa show highly specialized feeding strategies not found or rare in passeriform birds. It is detailed that no crown‐group members of modern‘families’ are known from pre‐Oligocene deposits of Europe, or anywhere else. The phylogenetic position of Paleogene birds thus indicates that diversification of the crown‐groups of modern avian‘families’ did not take place before the Oligocene, irrespective of their relative position within Neornithes (crown‐group birds). The Paleogene fossil record of birds does not even support crown‐group diversification of Galliformes, one of the most basal taxa of neognathous birds, before the Oligocene, and recent molecular studies that dated diversification of galliform crown‐group taxa into the Middle Cretaceous are shown to be based on an incorrect interpretation of the fossil taxa used for molecular clock calibrations. Several taxa that occur in the Paleogene of Europe have a very different distribution than their closest extant relatives. The modern survivors of these Paleogene lineages are not evenly distributed over the continents, and especially the great number of taxa that are today restricted to South and Central America is noteworthy. The occurrence of stem‐lineage representatives of many taxa that today have a restricted Southern Hemisphere distribution conflicts with recent hypotheses on a Cretaceous vicariant origin of these taxa, which were deduced from the geographical distribution of the basal crown‐group members.