bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of substrate size on the locomotion and gait patterns of the kinkajou (Potos flavus)
Authors: Lemelin Pierre , Cartmill Matt 
Published: January 2010

AbstractDiagonal‐sequence (DS) gaits, which are very rare among mammals, are common and well documented in primates and some arboreal marsupials. DS walking gaits have been reported in the kinkajou (Potos flavus), which shows ecological similarities with primates and arboreal opossums but lacks prehensile specializations of the hindfoot. Nevertheless, the actual frequency of DS gaits and the functional context in which these gaits occur in this highly arboreal mammal remain unknown. We examined the effect of substrate size on the locomotion and gait patterns of kinkajous by recording gaits in two individuals walking and running on poles of two different diameters and on a runway. Diagonality and limb duty factors were calculated for 534 gait cycles. Kinkajous relied mostly on DS gaits and trots during walking, and increased the diagonality of their gait patterns on thinner substrates. The proposed functional link between locomotion on thin branches and the presence of a grasping, primate‐like hindfoot is not supported by these data. However, further analysis of kinkajou gait cycles showed that DS gaits may have advantages overlooked earlier. DS gaits, during walking, minimize the distance between two ipsilateral feet during short periods of unilateral bipedality, and per corollary maximize the distance between two contralateral feet during the much longer periods of diagonal bipedality. Such foot positioning during the gait cycle could be beneficial in walking on a relatively thin substrate and could explain why kinkajous adopt DS walking gaits, especially on thinner poles, despite lacking prehensile specializations of the hindfoot. J. Exp. Zool. 313A:157–168, 2010. © 2010 Wiley‐Liss, Inc.
Identifying the germline in an equally cleaving mollusc: Vasa and Nanos expression during embryonic and larval development of the vetigastropod Haliotis asinina
Authors: Kranz Alexandrea M. , Tollenaere Alina , Norris Belinda J. , Degnan Bernard M. , Degnan Sandie M. 
Published: January 2010

AbstractMembers of the Vasa and Nanos gene families are important for the specification and development of the germline in diverse animals. Here, we determine spatial and temporal expression of Vasa and Nanos to investigate germline development in the vetigastropod Haliotis asinina. This is the first time these genes have been examined in an equally cleaving lophotrochozoan species. We find that HasVasa and HasNanos have largely overlapping, but not identical, expression patterns during embryonic and larval development, with both being maternally expressed and localized to the micromere cell lineages during cleavage. As embryonic development continues, HasVasa and HasNanos become progressively more enriched in the dorsal quadrant of the embryo. By the trochophore stage, both HasVasa and HasNanos are expressed in the putative mesodermal bands of the larva. This differs from the unequally cleaving gastropod Illyanasa obsoleta, in which IoVasa and IoNanos expression is detectable only in the early embryo and not during gastrulation and larval development. Our results suggest that the H. asinina germline arises from the 4d cell lineage and that primordial germ cells (PGCs) are not specified exclusively by maternally inherited determinants (preformation). As such, we infer that inductive signals (epigenesis) play an important role in specifying PGCs in H. asinina. We hypothesize that HasVasa is expressed in a population of undifferentiated multipotent cells, from which the PGCs are segregated later during development. J. Exp. Zool. (Mol. Dev. Evol.) 314B:267–279, 2010. © 2010 Wiley‐Liss, Inc.
Allometries and the morphogenesis of the molluscan shell: a quantitative and theoretical model
Authors: Urdy Séverine , Goudemand Nicolas , Bucher Hugo , Chirat Régis 
Published: January 2010

AbstractThis article explores the close relationships between growth rate and allometries of molluscan shells. After reviewing the previous theoretical approaches devoted to the understanding of shell form and its morphogenesis, we present a free‐form vector model which can simulate apertural shape changes and nonlinear allometries. Shell morphology is generated by iteratively adding a growth increment onto the last computed aperture. The first growth increment defines so‐called growth vectors which are assumed to be constant in direction (relative to the last computed aperture position) during a simulation of a shell (ontogeny). These growth vectors are uniformly scaled at each time step according to various growth rate curves that are used to simulate the mantle growth over time. From the model, we derive morphometric variables that illustrate the ontogenetic trajectories in time–size–shape space. We investigate the effects of changing the growth curves types, growth rate parameters and growth vector maps on the direction, speed and patterns of ontogenetic allometries. Because this model focuses the issue on time, it highlights a plausible effect of growth rate on shell shape and illustrates some fundamental geometrical properties of the logarithmic spiral, in particular the close relationship between the size and the geometry of growth increments. This model could be used to develop a mathematically data‐driven approach where experimentally obtained growth curves could be used as inputs in the model. More generally, our study recalls the role of growth rates in the generation of allometries.J. Exp. Zool. (Mol. Dev. Evol.) 314B:280–302, 2010. © 2010 Wiley‐Liss, Inc.
The evolutionary origins of gene regulation
Authors: Proulx Stephen R. , Smiley Michael W. 
Published: January 2010

AbstractOne way that organisms cope with constantly changing physical and biological conditions is by regulating the expression of genes and thereby altering protein production. Clearly, altering the protein production to match the environmental demands can be adaptive, but there may be evolutionary barriers to the transition from constitutive expression to regulated expression. In particular, down‐regulating a gene when it is not needed means that there will necessarily be a delay in protein production when the protein is up‐regulated in the future. We develop a model of simple gene regulation in response to randomly changing environmental conditions. We calculate the long‐term behavior of gene expression and determine the fitness consequences of changes in the gene regulation. We then embed this model into a population genetic framework in order to determine the conditions that allow populations to evolve environment‐specific transcription rates. The population genetic model follows the evolutionary transition from constitutive expression to regulated expression. There are three distinct possible evolutionary outcomes. The gene may be stuck in the always on position, the gene may first evolve to an intermediate constitutive expression level and then evolve regulation, or regulation can evolve directly from the ancestral state in a smooth fashion. Regulation is most likely to evolve when the costs of mis‐expression are low and the transcript decay rate is high. This suggests that genes that have less severe reductions in fitness when mis‐expressed are more likely to initially evolve regulation. J. Exp. Zool. (Mol. Dev. Ecol.) 314B:327–340, 2010. © 2010 Wiley‐Liss, Inc.
A within‐individual study of interpersonal conflict as a work stressor: Dispositional and situational moderators
Authors: Ilies Remus , Johnson Michael D. , Judge Timothy A. , Keeney Jessica 
Published: January 2010

AbstractFocusing on interpersonal conflict as a work stressor, the authors used a within‐subjects research design to examine the effect of conflict episodes on employees' negative affect on the job. The roles of agreeableness and social support in moderating the negative effects of conflict episodes were also examined. A two‐week experience‐sampling study revealed that interpersonal conflict influenced employees' intraindividual fluctuations in negative affect. As predicted, agreeableness and social support influenced individuals' patterns of affective responses to conflict, such that conflict was more strongly associated with negative affect for agreeable employees, and for those with lower levels of social support at work. Overall, the results suggest that both personality (agreeableness) and context (social support) significantly moderate the affective implications of interpersonal conflict at work. Copyright © 2010 John Wiley & Sons, Ltd.
Multiple‐column RP‐HPLC retention modelling based on solvatochromic or theoretical solute descriptors
Authors: D'Archivio Angelo Antonio , Maggi Maria Anna , Ruggieri Fabrizio 
Published: January 2010

AbstractRecently, we have proposed an approach to multi‐column RP‐HPLC retention modelling under isocratic conditions based on a combination of five molecular descriptors, the volume fraction of organic modifier in the mobile phase and a column descriptor, simultaneously considered as dependent variables of artificial neural network (ANN) regression. The column descriptor, in particular, was identified with the observed average retention of the solutes used in calibration extrapolated to pure water as the mobile phase. The ANN‐based model was seen to accurately describe retention on a pool of octadecylsiloxane‐bonded (C18) columns in a wide range of mobile phase composition. Reliability of this approach is further examined here by analysing the retention data of Reta et al. (Anal. Chem. 1999, 71, 3484–3496) referring to 17 aromatic compounds collected in water–methanol mobile phases at the compositions 45, 50, 55 and 60% v/v of methanol with eight different columns based on various hydrocarbon, fluorocarbon and aromatic bonded stationary phases. Further, in this study we compare the explanatory capability of two different kinds of molecular descriptors: the well‐known solvatochromic descriptors and theoretical descriptors extracted by genetic algorithm variable selection from the large set provided by the popular software Dragon.
Effect of high pressure on molecular interaction between oleic acid and base oils at elasthydrodynamic lubrication contact
Authors: Takiwatari Koji , Nanao Hidetaka , Mori Shigeyuki 
Published: January 2010

AbstractThe molecular interaction of oleic acid in different base oils at Elastohydrodynamic lubrication (EHL) contact was investigated by means of in‐situ observation with micro‐Fourier Transform Infrared Spectrometer (FTIR). Moreover, the effect of hydrostatic pressure was confirmed using a diamond‐anvil cell (DAC). Poly‐α‐olefin (PAO) with non‐polar, and Polypropylene glycol and Polybutylene glycol (PPG and PBG) which have ether group were used as base oil. When PAO was used, oleic acid interacts with itself to form a dimer. On the other hand, oleic acid interacts with PPG and PBG and exists mainly as a monomeric moelcule.The IR peak of C = O stretching mode of oleic acid dimmer was shifted to lower wavenumber at EHL contact region. The peak shift was not obvious in the case of the monomer. This result means that the hydrogen bonding of the dimer was stabilized under high pressure, but the hydrogen bonding of monomer was not. Copyright © 2010 John Wiley & Sons, Ltd.
Iron‐Containing Poly(propylene imine) Dendromesogens with Photoactive Properties
Authors: Domracheva Natalia E. , Morozov Vladimir I. , Gruzdev Matvey S. , Manapov Rafil A. , Pyataev Andrew V. , Lattermann Guenter 
Published: January 2010

AbstractHere, we report the first results of investigation the local structure and photoactive properties of iron‐containing dendromesogens based on decyloxybenzoate substituted poly(propylene imine) dendrimers of the first to fifth generations. Iron ions existing in a high‐spin state are coordinated in dendrimer ligands by two kinds of iron‐complexing sites with an octahedral and a tetrahedral symmetry. Octahedral (high‐symmetry) centers are located at the border of the dendrimeric core, while the tetrahedral centers with strong rhombic distortion of iron environment are distributed throughout all branching of the dendrimeric core. It has been found that all iron‐containing dendromesogens exhibit light‐harvesting and fluorescence properties.magnified image
Excitability properties of mouse motor axons in the mutant SOD1G93A model of amyotrophic lateral sclerosis
Authors: Boërio Delphine , Kalmar Bernadett , Greensmith Linda , Bostock Hugh 
Published: January 2010

AbstractNon‐invasive excitability studies of motor axons in patients with amyotrophic lateral sclerosis (ALS) have revealed a changing pattern of abnormal membrane properties with disease progression, but the heterogeneity of the changes has made it difficult to relate them to pathophysiology. The SOD1G93A mouse model of ALS displays more synchronous motoneuron pathology. Multiple excitability measures of caudal and sciatic nerves in mutant and wild‐type mice were compared before onset of signs and during disease progression (4–19 weeks), and they were related to changes in muscle fiber histochemistry. Excitability differences indicated a modest membrane depolarization in SOD1G93A axons at about the time of symptom onset (8 weeks), possibly due to deficient energy supply. Previously described excitability changes in ALS patients, suggesting altered sodium and potassium conductances, were not seen in the mice. This suggests that those changes relate to features of the human disease that are not well represented in the animal model. Muscle Nerve, 2010
Release of inflammatory mediators by adipose tissue during acute pancreatitis
Authors: Franco‐Pons Neus , Gea‐Sorlí Sabrina , Closa Daniel 
Published: January 2010

AbstractObesity and lipid metabolism are associated with the severity of acute pancreatitis. Fat necrosis appears in the severe acute pancreatitis as a consequence of the release of lipolytic enzymes, but its potential role on the progression of the disease is unclear. In this study, we have examined the role of white adipose tissue as a source of inflammatory mediators that can promote systemic inflammation during experimental taurocholate‐induced acute pancreatitis in rats. The inflammatory status and the expression of TNFα, iNOS, adiponectin and IL‐10 were determined in necrotic and non‐necrotic areas of adipose tissue. Samples of adipose tissue were also used to induce the activation of macrophages in vitro. Finally, the release of TNFα to mesenterial vessels surrounded by necrotic or non‐necrotic fat was evaluated in ex vivo perfused mesenterium. A strong inflammatory infiltrate was observed in the border between necrotic and non‐necrotic areas of adipose tissue. In these areas, high expression of TNFα and iNOS and a reduced expression of IL‐10 were observed, while adiponectin showed only a moderate increase. Necrotic fat strongly activates peritoneal macrophages in vitro. Mesenterial areas with fat necrosis release to the vascular vessels significantly increased amounts of TNFα when compared to vessels without necrosis. Altogether, these results indicate that adipose tissue inflammation is a process secondary to acute pancreatitis but also contributes to the generation of mediators potentially involved in the induction of the systemic inflammatory response. In particular, the areas of fat necrosis are important sources of inflammatory mediators. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Anaplastic plasmacytomas: relationships to normal memory B cells and plasma cell neoplasms of immunodeficient and autoimmune mice
Authors: Qi Chen‐Feng , Shin Dong‐Mi , Li Zhaoyang , Wang Hongsheng , Feng Jianxum , Hartley Janet W , Fredrickson Torgny N , Kovalchuk Alexander L , Morse Herbert C 
Published: January 2010

AbstractAnaplastic plasmacytomas (APCTs) from NFS.V+ congenic mice and pristane‐induced plasmacytic PCTs from BALB/c mice were previously shown to be histologically and molecularly distinct subsets of plasma cell neoplasms (PCNs). Here we extended these comparisons, contrasting primary APCTs and PCTs by gene expression profiling in relation to the expression profiles of normal naïve, germinal centre, and memory B cells and plasma cells. We also sequenced immunoglobulin genes from APCT and APCT‐derived cell lines and defined surface phenotypes and chromosomal features of the cell lines by flow cytometry and by spectral karyotyping and fluorescence in situ hybridization. The results indicate that APCTs share many features with normal memory cells and the plasma cell‐related neoplasms (PLs) of FASL‐deficient mice, suggesting that APCTs and PLs are related and that both derive from memory B cells. Published in 2010 by John Wiley & Sons, Ltd.
Microwave absorption property of polyaniline nanocomposites containing TiO2 and Fe3O4 nanoparticles after FeCl36H2O treatment
Authors: Phang Sook Wai , Kuramoto Noriyuki 
Published: January 2010

AbstractIt is important to manipulate the synthesis parameters or additives used in order to produce conducting polymer such as polyaniline (PAni) with moderate conductivity, magnetic and dielectric properties that could enhance its microwave absorbing and shielding properties. In this communication, novel PAni/HA/TiO2/Fe3O4 nanomaterials with different Fe3O4 contents were prepared by template‐free method by using TiO2 and Fe3O4 nanoparticles as dielectric filler and magnetic filler, respectively. Before addition of ammonium peroxydisulfate (APS) for polymerization, Fe3O4 aqueous solution was treated with FeCl36H2O in order to disperse well the Fe3O4 in the mixture. The result shows that better dispersion of Fe3O4 in the mixture by FeCl36H2O treatment could significantly improve the conductivity of the nanocomposites and also activate the formation of nanorods/tubes. Moreover, PAni/HA/TiO2/Fe3O4 nanocomposites treated with FeCl36H2O show better microwave absorption (99.950–99.999% absorption) compared with PAni/HA/TiO2/Fe3O4 micro/nanocomposites (67.0− 99.4% absorption) without treatment in frequency range of 10–13 GHz. Among the prepared PAni/HA/TiO2/Fe3O4 micro/nanocomposites and nanocomposites, PAni/HA/TiO2/Fe3O4 nanocomposite (treated with FeCl36H2O) with 40% Fe3O4 exhibit the best microwave absorption (99.999% absorption at 10 GHz) because of its high conductivity, high heterogeneity and moderate magnetization. POLYM. COMPOS., 2010. © 2010 Society of Plastics Engineers
Critical biophysical properties in the Pseudomonas aeruginosa efflux gene regulator MexR are targeted by mutations conferring multidrug resistance
Authors: Andrésen Cecilia , Jalal Shah , Aili Daniel , Wang Yi , Islam Sohidul , Jarl Anngelica , Liedberg Bo , Wretlind Bengt , Mårtensson Lars‐Göran , Sunnerhagen Maria 
Published: January 2010

AbstractThe self‐assembling MexA‐MexB‐OprM efflux pump system, encoded by the mexO operon, contributes to facile resistance of Pseudomonas aeruginosa by actively extruding multiple antimicrobials. MexR negatively regulates the mexO operon, comprising two adjacent MexR binding sites, and is as such highly targeted by mutations that confer multidrug resistance (MDR). To understand how MDR mutations impair MexR function, we studied MexR‐wt as well as a selected set of MDR single mutants distant from the proposed DNA‐binding helix. Although DNA affinity and MexA‐MexB‐OprM repression were both drastically impaired in the selected MexR‐MDR mutants, MexR‐wt bound its two binding sites in the mexO with high affinity as a dimer. In the MexR‐MDR mutants, secondary structure content and oligomerization properties were very similar to MexR‐wt despite their lack of DNA binding. Despite this, the MexR‐MDR mutants showed highly varying stabilities compared with MexR‐wt, suggesting disturbed critical interdomain contacts, because mutations in the DNA‐binding domains affected the stability of the dimer region and vice versa. Furthermore, significant ANS binding to MexR‐wt in both free and DNA‐bound states, together with increased ANS binding in all studied mutants, suggest that a hydrophobic cavity in the dimer region already shown to be involved in regulatory binding is enlarged by MDR mutations. Taken together, we propose that the biophysical MexR properties that are targeted by MDR mutations—stability, domain interactions, and internal hydrophobic surfaces—are also critical for the regulation of MexR DNA binding.
Drug binding and resistance mechanism of KIT tyrosine kinase revealed by hydrogen/deuterium exchange FTICR mass spectrometry
Authors: Zhang Hui‐Min , Yu Xiu , Greig Michael J. , Gajiwala Ketan S. , Wu Joe C. , Diehl Wade , Lunney Elizabeth A. , Emmett Mark R. , Marshall Alan G. 
Published: January 2010

AbstractMutations of the receptor tyrosine kinase KIT are linked to certain cancers such as gastrointestinal stromal tumors (GISTs). Biophysical, biochemical, and structural studies have provided insight into the molecular basis of resistance to the KIT inhibitors, imatinib and sunitinib. Here, solution‐phase hydrogen/deuterium exchange (HDX) and direct binding mass spectrometry experiments provide a link between static structure models and the dynamic equilibrium of the multiple states of KIT, supporting that sunitinib targets the autoinhibited conformation of WT‐KIT. The D816H mutation shifts the KIT conformational equilibrium toward the activated state. The V560D mutant exhibits two low energy conformations: one is more flexible and resembles the D816H mutant shifted toward the activated conformation, and the other is less flexible and resembles the wild‐type KIT in the autoinhibited conformation. This result correlates with the V560D mutant exhibiting a sensitivity to sunitinib that is less than for WT KIT but greater than for KIT D816H. These findings support the elucidation of the resistance mechanism for the KIT mutants.
Computational study on the carboligation reaction of acetohidroxyacid synthase: New approach on the role of the HEThDP− intermediate
Authors: Jaña Gonzalo , Jiménez Verónica , Villà‐Freixa Jordi , Prat‐Resina Xavier , Delgado Eduardo , Alderete Joel 
Published: January 2010

AbstractAcetohydroxyacid synthase (AHAS) is a thiamin diphosphate dependent enzyme that catalyses the decarboxylation of pyruvate to yield the hydroxyethyl‐thiamin diphosphate (ThDP) anion/enamine intermediate (HEThDP–). This intermediate reacts with a second ketoacid to form acetolactate or acetohydroxybutyrate as products. Whereas the mechanism involved in the formation of HEThDP– from pyruvate is well understood, the role of the enzyme in controlling the carboligation reaction of HEThDP– has not been determined yet. In this work, molecular dynamics (MD) simulations were employed to identify the aminoacids involved in the carboligation stage. These MD studies were carried out over the catalytic subunit of yeast AHAS containing the reaction intermediate (HEThDP–) and a second pyruvate molecule. Our results suggest that additional acid–base ionizable groups are not required to promote the catalytic cycle, in contrast with earlier proposals. This finding leads us to postulate that the formation of acetolactate relies on the acid–base properties of the HEThDP– intermediate itself. PM3 semiempirical calculations were employed to obtain the energy profile of the proposed mechanism on a reduced model of the active site. These calculations confirm the role of HEThDP– intermediate as the ionizable group that promotes the carboligation and product formation steps of the catalytic cycle. Proteins 2010. © 2010 Wiley‐Liss, Inc.