bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure of the catalytic domain of the human mitochondrial Lon protease: Proposed relation of oligomer formation and activity
Authors: García‐Nafría Javier , Ondrovičová Gabriela , Blagova Elena , Levdikov Vladimir M. , Bauer Jacob A. , Suzuki Carolyn K. , Kutejová Eva , Wilkinson Anthony J. , Wilson Keith S.
Published: March 2010

ATP‐dependent proteases are crucial for cellular homeostasis. By degrading short‐lived regulatory proteins, they play an important role in the control of many cellular pathways and, through the degradation of abnormally misfolded proteins, protect the cell from a buildup of aggregates. Disruption or disregulation of mammalian mitochondrial Lon protease leads to severe changes in the cell, linked with carcinogenesis, apoptosis, and necrosis. Here we present the structure of the proteolytic domain of human mitochondrial Lon at 2 Å resolution. The fold resembles those of the three previously determined Lon proteolytic domains from Escherichia coli, Methanococcus jannaschii, and Archaeoglobus fulgidus. There are six protomers in the asymmetric unit, four arranged as two dimers. The intersubunit interactions within the two dimers are similar to those between adjacent subunits of the hexameric ring of E. coli Lon, suggesting that the human Lon proteolytic domain also forms hexamers. The active site contains a 310 helix attached to the N‐terminal end of α‐helix 2, which leads to the insertion of Asp852 into the active site, as seen in M. jannaschii. Structural considerations make it likely that this conformation is proteolytically inactive. When comparing the intersubunit interactions of human with those of E. coli Lon taken with biochemical data leads us to propose a mechanism relating the formation of Lon oligomers with a conformational shift in the active site region coupled to a movement of a loop in the oligomer interface, converting the proteolytically inactive form seen here to the active one in the E. coli hexamer.
Specific interactions of sticholysin I with model membranes: An NMR study
Authors: Castrillo Inés , Araujo Nelson A. , Alegre‐Cebollada Jorge , Gavilanes José G. , Martínez‐del‐Pozo Álvaro , Bruix Marta
Published: March 2010

Sticholysin I (StnI) is an actinoporin produced by the sea anemone Stichodactyla helianthus that binds biological and model membranes forming oligomeric pores. Both a surface cluster of aromatic rings and the N‐terminal region are involved in pore formation. To characterize the membrane binding by StnI, we have studied by 1H‐NMR the environment of these regions in water and in the presence of membrane‐mimicking micelles. Unlike other peptides from homologous actinoporins, the synthetic peptide corresponding to residues 1–30 tends to form helix in water and is more helical in either trifluoroethanol or dodecylphosphocholine (DPC) micelles. In these environments, it forms a helix‐turn‐helix motif with the last α‐helical segment matching the native helix‐α1 (residues 14–24) present in the complete protein. The first helix (residues 4–9) is less populated and is not present in the water‐soluble protein structure. The characterization of wild‐type StnI structure in micelles shows that the helix‐α1 is maintained in its native structure and that this micellar environment does not provoke its detachment from the protein core. Finally, the study of the aromatic resonances has shown that the motional flexibility of specific rings is perturbed in the presence of micelles. On these bases, the implication of the aromatic rings of Trp‐111, Tyr‐112, Trp‐115, Tyr‐132, Tyr‐136, and Tyr‐137, in the interaction between StnI and the micelle is discussed. Based on all the findings, a revised model for StnI interaction with membranes is proposed, which accounts for differences in its behavior as compared with other highly homologous sticholysins. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Targeting Cydia pomonella (L.) (Lepidoptera: Tortricidae) adults with low‐volume applications of insecticides alone and in combination with sex pheromone
Authors: Knight Alan L
Published: March 2010

BACKGROUND: Studies surveyed the toxicity of several insecticides against adult codling moth, Cydia pomonella (L.), and examined the field effectiveness of applying low‐volume (12 L ha−1) sprays alone or in combination with a microencapsulated (MEC) sex pheromone formulation.

RESULTS: Neonicotinyls, organophosphates and synthetic pyrethroids significantly reduced fecundity at concentrations nearly 100‐fold lower than their maximum labeled field rate. Field studies in 2005 demonstrated that six applications of esfenvalerate resulted in > 90% reduction in fruit injury versus the untreated check. The addition of the MEC pheromone formulation did not further improve control. Five sprays of esfenvalerate, phosmet and acetamiprid all significantly reduced levels of fruit injury compared with the untreated control in 2006. Esfenvalerate and acetamiprid mixed with the MEC pheromone significantly reduced fruit injury compared with the MEC‐only treatment. Significant increases in pest and decreases in predator mite densities occurred in plots treated with esfenvalerate in both years. Low‐volume sprays of phosmet and acetamiprid did not disrupt mites.

CONCLUSION: Low‐volume insecticide sprays can effectively manage codling moth and are less disruptive of integrated mite management. Developing an effective ‘attract and kill’ technology with this approach will require optimization of the attractant(s) to maximize moth exposure to insecticide residues. Published 2010 by John Wiley & Sons, Ltd.
Aesculus pavia foliar saponins: defensive role against the leafminer Cameraria ohridella
Authors: Ferracini Chiara , Curir Paolo , Dolci Marcello , Lanzotti Virginia , Alma Alberto
Published: March 2010

BACKGROUND: Recently, the leafminer Cameraria ohridella Deschka & Dimic has caused heavy damage to the white‐flowering horse chestnut in Europe. Among the Aesculus genus, A. pavia L. HBT genotype, characterised by red flowers, showed an atypical resistance towards this pest. Its leaves, shaken in water, originated a dense foam, indicating the presence of saponins, unlike the common horse chestnut tree. The aim was to isolate and identify these leaf saponins and test their possible defensive role against C. ohridella.

RESULTS: Spectroscopic analyses showed that A. pavia HBT genotype leaves contained a mixture of saponins, four of which were based on the same structure as commercial escin saponins, the typical saponin mixture produced by A. hippocastanum and accumulated only within bark and fruit tissues. The mixture showed a repellent effect on C. ohridella moth. The number of mines detected on the leaves of A. hippocastanum plants treated with A. pavia HBT saponins through watering and stem brushing was significantly lower than the control, and in many cases no mines were ever observed.

CONCLUSION: The results showed that the exogenous saponins were translocated from roots/stem to the leaf tissues, and their accumulation seemed to ensure an appreciable degree of protection against the leafminer. Copyright © 2010 Society of Chemical Industry
Amorphous silicon: Vehicle and test bed for large‐area electronics
Authors: Wagner Sigurd
Published: March 2010

This paper is an informal transcript of the Mott Lecture given at ICANS 23 in Utrecht. While the writer was fortunate to still have seen and heard Sir Nevill Mott at conferences, he came to know him mostly through stories and comments that told of his enthusiasm, his wide‐ranging interests, and the pleasure of interacting with him. Nevill Mott was the guide in preparing this brief account of the success story that amorphous silicon has become, and of what still may come of it. What would he have liked to learn about it today? The Lecture and the present account also reflect the writer's research interest in electronic materials. He wants to convey his opinion that hydrogenated forms of thin‐film silicon, having become the foundation of a large industry, still hold tremendous promise for research and for application.

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LP MOCVD growth of InAlN/GaN HEMT heterostructure: comparison of sapphire, bulk SiC and composite SiCopSiC substrates for HEMT device applications
Authors: di Forte Poisson M.‐A. , Sarazin N. , Magis M. , Tordjman M. , Di Persio J. , Langer R. , Iliopoulos E. , Georgakilas A. , Kominou P. , Guziewicz M. , Kaminska E. , Piotrowska A. , Gaquière C. , Oualli M. , Chartier E. , Morvan E. , Delage S.
Published: March 2010

In this paper we report on low‐pressure metalorganic vapour deposition of InAlN/GaN heterostructures grown on different substrates (Sapphire, bulk SiC, composite SiCopSiC) for HEMT applications, and on first device performances obtained with these heterostructures. Optimisation of the crystal growth on each kind of substrate has led to InAlN/GaN HEMT heterostructures grown on bulk SiC and on composite SiCopSiC substrates which are successfully compared, in terms of material quality, to the standard GaAlN/GaN HEMT heterostructures grown on bulk SiC substrates. First devices based on InAlN/GaN heterostructures grown on bulk SiC exhibit very good microwave performances, with output power of 10.3 W/mm at 10 GHz, similar to those obtained with GaAlN/GaN heterostructures, confirming the promising potential of InAlN material. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface photovoltage spectroscopy ‐ method and applications
Authors: Cavalcoli Daniela , Cavallini Anna
Published: March 2010

Surface photovoltage spectroscopy (SPS) allows for obtaining a detailed picture of the electronic structure of semiconductors. In SPS, changes in band bending at the free semiconductor surface are monitored as a function of external illumination. Surface photovoltage spectroscopy can provide detailed, quantitative information on bulk properties (e.g. bandgap and conductivity type, defect states energy, and lifetime) and can be used for complete construction of surface and interface band diagrams, including the measurement of energy levels in quantum structures. Measurements using SPS are contactless and non‐destructive. In addition, they can be performed both in situ and ex situ, at any reasonable temperature, on many semiconducting materials, at any ambient and at any lateral resolution down to the atomic scale. In this review an overview of SPS‐related theory is presented, the SPS experimental set‐up is described and applications for the characterization of a wide variety of materials and structures are presented (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
How to design single‐column model experiments for comparison with observed nocturnal low‐level jets
Authors: Baas P. , Bosveld F.C. , Lenderink G. , van Meijgaard E. , Holtslag A. A. M.
Published: March 2010

Single‐column models (SCMs) are widely employed to evaluate boundary‐layer parametrizations under well‐controlled conditions. To compare SCM results to observations, these models must be driven by realistic forcings of the three‐dimensional (3D) atmospheric state. However, these forcings are inherently uncertain. The central research question is therefore: can observations be used to distinguish between different parametrization schemes in SCM simulations or is the spread due to uncertainties in the forcings too large? This study investigates this question for the nocturnal low‐level jet (LLJ) at Cabauw. First, we analyse a single LLJ case that has been used for the third GEWEX Atmospheric Boundary Layer Studies (GABLS3) intercomparison study. To estimate the forcings, for this case a blend of local observations and 3D model output has been used. A sensitivity study to both the forcings and the turbulence formulation is performed by using the SCM version of the ECMWF model. The sensitivity to the turbulence parametrization is largest in the bulk of the stable boundary layer (SBL). The influence of the forcings manifests itself mainly in the upper part of the SBL and above. Second, an ensemble of eight comparable LLJ cases is considered. Using forcings derived from 3D model integrations, SCM results of the separate cases show significant deviations from the observations. However, the mean of the SCM simulations agrees well with the mean of the observations. Based on the eight selected LLJ cases, a composite SCM case is defined from the mean forcings of the 3D model. This improves the signal‐to‐noise ratio, which enables a better judgement of the quality of boundary‐layer parametrizations in a comparison with the observations. Copyright © 2010 Royal Meteorological Society
The role of exact‐exchange in the theoretical description of organic‐metal interfaces
Authors: Sala Fabio Della , Fabiano Eduardo , Laricchia Savio , D'Agostino Stefania , Piacenza Manuel
Published: March 2010

We investigate the ability of different density functional methods to describe the electronic properties of isolated gold clusters, self‐assembled monolayers (SAM) of oligophenylthiols (including the depolarization effect), and the biphenylthiol/gold interface. To elucidate the role of the exchange interaction, we consider a hierarchy of functionals including conventional (e.g., within the gradient corrected approximation), hybrid, and effective exact‐exchange functionals, namely the Localized Hartree–Fock (LHF) method, which is free from the self‐interaction‐error (SIE).

We find that conventional exchange‐correlation functionals cannot well describe the energy‐level alignment at the metal/organic interface and predict a negligible metal‐molecule charge‐transfer. In addition, an overestimation of dipole moments and polarization effects are obtained in oligophenylthiols, leading to a wrong description of the SAM depolarization effect. Both limitations are mostly overcome if exact‐exchange contributions are taken into account either using an hybrid functional or the LHF method. In particular, an accurate description of the metal/organic interface is only achieved using SIE free methods. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Bias‐exchange metadynamics applied to the study of chemical reactivity
Authors: Bulo Rosa E. , Van Schoot Hans , Rohr Daniel , Michel Carine
Published: March 2010

We show how the combination of Bias Exchange metadynamics (BE) with Car‐Parrinello molecular dynamics (CPMD) can lead to vast improvements in the study of chemical reactions. Bias Exchange metadynamics is a recently introduced methodology that combines replica exchange techniques with the metadynamics approach. It allows fast parallel reconstruction of the free energy of a system in a virtually unlimited number of variables. The value of the method was previously demonstrated for the folding of a Triptophane cage miniprotein on the classical potential energy surface. As a test case for the DFT implementation, we investigated the competitive SN2 reaction of CH3Cl with Cl− and Br−. The results illustrate three important advantages of the method. (1) Fast and complete sampling of configuration space occurs in each replica. (2) A significant speed‐up can be observed in the convergence of the free energy profiles, compared with regular metadynamics. (3) The best conformational distributions are successfully transferred from one replica to the others. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Elongation cutoff technique at Kohn–Sham level of theory
Authors: Korchowiec Jacek , de Silva Piotr , Makowski Marcin , Gu Feng Long , Aoki Yuriko
Published: March 2010

The elongation cutoff technique ELG/C belongs to fragmentation methods. It uses the concept of locality and takes into account the sparsity of Kohn–Sham (KS) matrix in regionally localized molecular orbital basis set. In this article, a linear‐scaling implementation of ELG/C method at Kohn–Sham (KS) level of theory is presented. Its efficiency and accuracy is discussed for model system. The ELG/C KS scheme is based on local exchange‐correlation space approximation. Such approximation improves efficiency of the method and does not introduce a significant error. The current analysis includes the overall CPU (central processing unit) time and its most time consuming steps. The obtained results indicate that the ELG/C is a very efficient and accurate computational scheme. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Scale‐free graphs of increasing degree
Authors: Cooper Colin , Prałat Paweł
Published: March 2010

We study a scale‐free random graph process in which the number of edges added at each step increases. This differs from the standard model in which a fixed number,m, of edges are added at each step.

Letf(t) be the number of edges added at stept. In the standard scale‐free model,f(t) =mconstant, whereas in this paper we considerf(t) = [tc],c> 0. Such a graph process, in which the number of edges grows non‐linearly with the number of vertices is said to have accelerating growth.

We analyze both an undirected and a directed process. The power law of the degree sequence of these processes exhibits widely differing behavior.

For the undirected process, the terminal vertex of each edge is chosen by preferential attachment based on vertex degree. Whenf(t) =mconstant, this is the standard scale‐free model, and the power law of the degree sequence is 3. Whenf(t) = [tc],c< 1, the degree sequence of the process exhibits a power law with parameterx= (3 −c)/(1 −c). Asc→ 0,x→ 3, which gives a value ofx= 3, as in standard scale‐free model. Thus no more slowly growing monotone functionf(t) alters the power law of this model away fromx= 3. Whenc= 1, so thatf(t) =t, the expected degree of all vertices ist, the vertex degree is concentrated, and the degree sequence does not have a power law.

For the directed process, the terminal vertex is chosen proportional to in‐degree plus an additive constant, to allow the selection of vertices of in‐degree zero. For this process whenf(t) =mis constant, the power law of the degree sequence isx= 2 + 1/m. Whenf(t) = [tc],c> 0, the power law becomesx= 1 + 1/(1 +c), which naturally extends the power law to [1,2]. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 38, 396–421, 2011
Sheet AA2024‐T3: a new investigation of microstructure and composition
Authors: Hughes A. E. , MacRae C. , Wilson N. , Torpy A. , Muster T. H. , Glenn A. M.
Published: March 2010

Sheet AA2024‐T3 is probably one of the most studied aluminium alloys in the corrosion field, because, with copper as an alloying addition, it is one of the most corrosion‐prone aluminium alloys. This paper reports new findings on the composition and distribution of intermetallic (IM) particles in AA2024‐T3 through the examination of over 80 000 compositional domains in nearly 18 000 IM particles. This work was achieved by using an electron microprobe to map out 2 × 2 mm2 at a step size of 400 nm. This study revealed that the composition of individual particles can vary considerably from ‘accepted’ compositions. Domains within particles were extensive across the surface. Because such a large area was mapped, it was possible to subdivide this area and to look at the variation of particle statistics from region to region, providing some information on the statistical variation for small electrodes. Copyright © 2010 John Wiley & Sons, Ltd.
The influence of pre‐treatments of aluminium alloys on bonding of PET coatings
Authors: De Wit F. M. , Özkanat Ö. , Mol J. M. C. , Terryn H. , De Wit J. H. W.
Published: March 2010

Application of organic coatings on aluminium alloys is commonplace for corrosion protection. The adhesion of coatings is of great importance to the final protection properties. It is therefore necessary to understand on a molecular level the mechanisms with which a coating is able to bond. In this paper, we explore the possibilities of combining model molecules for a poly(ethylene terephthalate) (PET) type coating, di‐methyl terephthalate (DMT), with differently pre‐treated samples of AA1050 and AA5182 alloys. Bonding is studied by means of Fourier‐transform infrared (FTIR) spectroscopy. Because the type of bonding gives a direction for adhesion of a coated system, we also test (macroscopically) the adhesion of PET coatings with a novel technique: asymmetrical double cantilever beam (ADCB). In this method, a thin knife is used as a wedge on the interface of the alloy and the polymer. The displacement of the crack front as measured from the knife's contact point with the coating is used as an input parameter to obtain the adhesion energy for various systems. We show that there is a relationship between the character of bonding of DMT molecules and adhesion energies of PET on both alloys after pre‐treatments in alkali and acid and boiling in water. Copyright © 2010 John Wiley & Sons, Ltd.
Phagocytosis of Apoptotic Cells Modulates Mesenchymal Stem Cells Osteogenic Differentiation to Enhance IL-17 and RANKL Expression on CD4+ T Cells
Authors: Tso Gloria Hoi Wan , Law Helen Ka Wai , Tu Wenwei , Chan Godfrey Chi Fung , Lau Yu Lung
Published: March 2010

Osteogenic differentiation of mesenchymal stem cells (MSC) is important to homeostatic bone remodeling. Infiltration of mesenchymal progenitor cells to inflamed joints has been reported in collagen-induced arthritis murine model and in patients with rheumatoid arthritis (RA). Therapeutic application of MSC in RA has been suggested and under investigation. However, the underlying mechanisms on what triggers the migration of MSC from bone marrow (BM) to inflamed joints and how MSC acts in the joints remains elusive. As hemopoietic stem cells and MSC act reciprocally and excessive apoptotic cells (AC) are observed in the BM of patients with RA, we hypothesize that AC may alter MSC osteogenic differentiation resulting in bone erosion in RA. In this study, we demonstrated for the first time that MSC were able to phagocytose AC and this phagocytosis enhanced MSC osteogenic differentiation. AC-treated MSC under osteogenic differentiation expressed CXC-chemokine receptor (CXCR)-4 and CXCR5, which might enable them to migrate toward the inflamed joints. In addition, AC-treated MSC secreted interleukin (IL)-8, monocyte chemoattractant protein-1, and RANTES, which might induce chemotaxis of CD4+ T cells to the inflamed joints. Interestingly, by coculturing AC-treated MSC under osteogenic differentiation with CD4+ T cells, T helper (Th) 17 cells development was significantly enhanced and these Th17 cells promoted osteoclasts formation and bone resorption. Furthermore, the induction of Th17 cells was dependent on increased IL-6 production from major histocompatibility complex class II-expressing AC-treated MSC under osteogenic differentiation. This data provide a novel insight on the role of AC in modulating MSC osteogenic differentiation and function in inflammatory bone diseases.
A testing strategy for abstract classes
Authors: Clarke Peter J. , Power James F. , Babich Djuradj , King Tariq M.
Published: March 2010

One of the characteristics of the increasingly widespread use of object‐oriented libraries and the resulting intensive use of inheritance is the proliferation of dependencies on abstract classes. Since abstract classes cannot be instantiated, they cannot be tested in isolation using standard execution‐based testing strategies. A standard approach to testing abstract classes is to instantiate a concrete descendant class and test the features that are inherited. This paper presents a structured approach that supports the testing of features in abstract classes, paying particular attention to ensuring that the features tested are those defined in the abstract class. Two empirical studies are performed on a suite of large Java programs and the results presented. The first study analyses the role of abstract classes from a testing perspective. The second study investigates the impact of the testing strategy on the programs in this suite to demonstrate its feasibility and to comment on the pragmatics of its use. Copyright © 2010 John Wiley & Sons, Ltd.
Research summary on long‐span connected tall building structure with viscous dampers
Authors: Chen Xue‐Wei , Han Xiao‐Lei
Published: March 2010

The HUBα‐Sightseeing Gate in Guangzhou, which is a connected tall building structure, is composed of two main frame–shear wall towers, which are 86·5 m high, and two steel galleries at top and bottom, respectively. The top gallery is a 120 m long‐span steel truss. Vicious dampers are set in the two main towers and the top gallery. It is an ultra‐limit structure with complicated structural shape and hybrid structure system. Design idea of performance‐based seismic design is presented in this paper. Seismic performance of the structure under different levels of ground motion is analysed and verified by different methods, such as elastic analysis under frequent earthquake, unyielding and elastic check of structure element under medium earthquake and inelastic dynamic time history analysis under rare earthquake. Taking the result of shaking table test as a reference, reasonable enhanced measures of seismic design are suggested. Meanwhile, wind‐induced vibration time history analysis under different directions based on wind tunnel test is applied in this paper, and comfortableness problem can be well resolved. The control effects of vicious dampers on internal force, deformation, acceleration and energy dissipation of the structure are also studied. By means of the analysis methods mentioned above, and other analyses such as whole structure stability, temperature effect, floor vibration and so on, relevant measures of ultra‐limit structure design are suggested, and the performance objective of the structure can be well realized. Copyright © 2010 John Wiley & Sons, Ltd.
Modeling impacts and adaptation in global IAMs
Authors: Füssel Hans‐Martin
Published: March 2010

Integrated assessment models (IAMs) of climate change combine dynamic descriptions of the energy‐economy system, the climate system, and climate impacts to support the formulation of global, and possibly regional, climate policy. Originally they have been designed to inform mitigation policy but some of them are now applied in the context of adaptation policy as well. This article reviews the modeling of climate impacts and adaptation in global IAMs, including both models with an economic focus and models with a science focus. Key advances in the representation of climate impacts in IAMs during the last decade include improved consideration of differences in impacts across regions, the development of nonmonetary reduced‐form climate impact models, and coupling of global IAMs with regional and sectoral impact models to assess climate change together with other sustainability issues. Further advances include a stronger focus on probabilistic analysis and attempt at considering large‐scale climate instabilities. Adaptation has received only limited attention in global IAMs so far, mostly due to the mismatch in spatial scales at which mitigation and adaptation decisions are generally made. Some recent IAMs attempt to identify optimal levels of adaptation in climate‐sensitive sectors or do include adaptation to climate change explicitly as a decision variable. The main reason for the consideration of adaptation in global welfare‐maximizing IAMs is to assess the sensitivity of mitigation targets to different assumptions about the magnitude and effectiveness of adaptation. IAMs with geographically explicit impact models may also provide information that is useful for adaptation planning. Copyright © 2010 John Wiley & Sons, Ltd.

This article is categorized under:

Integrated Assessment of Climate Change > Integrated Assessment Modeling
Mitotic catastrophe induced by overexpression of budding yeast Rad2p
Authors: Kang Mi‐Sun , Yu Sung‐Lim , Lim Hyun‐Sook , Choi Bohwa , Park Chang‐Shin , Kang Ju‐Hee , Lee Sung‐Keun
Published: March 2010

Mitotic catastrophe provokes endopolyploidy, giant cell formation and, eventually, delayed cell death. Mitotic catastrophe is induced by defective cell cycle checkpoints and by some anticancer drugs, ionizing radiation and microtubule‐destabilizing agents. RAD2 is a yeast homologue of XPG, which is a human endonuclease involved in nucleotide excision repair. Here we show that Rad2p overexpression alone, in the absence of extrinsic DNA damage, causes cell growth arrest and mitotic catastrophe. Interestingly, Rad2p‐induced cell growth arrest is not caused by the catalytic activity of Rad2p but rather by its C‐terminal region. Cells growth‐arrested by Rad2p induction do not show apoptotic phenotypes and deletion of YCA1, a yeast caspase homologue, does not affect cell growth arrest by Rad2p induction. However, Rad2p‐induced cell growth arrest is released by rad9 deletion but is not affected by downstream DNA damage checkpoint genes. These observations suggest that RAD2 has a function in coordinating cell cycle regulation and damaged DNA repair. Copyright © 2010 John Wiley & Sons, Ltd.
Superpredation patterns in four large European raptors
Authors: Lourenço Rui , Santos Sara Maria , Rabaça João Eduardo , Penteriani Vincenzo
Published: March 2010

Predatory interactions among top predators, like superpredation or intraguild predation (IGP), can influence community structure. Diurnal raptors occupy high trophic levels in terrestrial food webs, and thus can regulate the presence of mesopredators. We studied superpredation (the killing and eating of another predator) in four large European raptors. We gathered 121 dietary studies, totalling 161,456 prey for the Goshawk Accipiter gentilis L., Golden Eagle Aquila chrysaetos L., Bonelli's Eagle Aquila fasciata Vieillot, and Eagle Owl Bubo bubo L. Results showed that superpredation: (1) is a widespread interaction in large raptors, but it can vary according to the top predator species; (2) is not an important energetic resource for large raptors, but rather seems mostly related to diet diversification when the main prey decreases; (3) is spatially clustered reflecting habitat heterogeneity, but shows no temporal or large‐scale spatial trends; and (4) it is associated with lower breeding success of the top predator species. These findings support the food stress hypothesis as the main driving force behind increases in superpredation and IGP in raptors, with the decrease in breeding performance as a side effect. Superpredation by large raptors deserves future research to understand its effects on mesopredators, because on one hand it might contribute to promote biodiversity, while on the other hand, it can sometimes represent an additional risk for small populations of endangered mesopredators.
α‐Synuclein induced membrane depolarization and loss of phosphorylation capacity of isolated rat brain mitochondria: Implications in Parkinson's disease
Authors: Banerjee Kalpita , Sinha Maitrayee , Pham Chi Le Lan , Jana Sirsendu , Chanda Dalia , Cappai Roberto , Chakrabarti Sasanka
Published: March 2010

This study demonstrates that in vitro incubation of isolated rat brain mitochondria with recombinant human α‐synuclein leads to dose‐dependent loss of mitochondrial transmembrane potential and phosphorylation capacity. However, α‐synuclein does not seem to have any significant effect on the activities of respiratory chain complexes under similar conditions of incubation suggesting that the former may impair mitochondrial bioenergetics by direct effect on mitochondrial membranes. Moreover, the recombinant wild type α‐synuclein and different mutant forms (A30P, A53T and E46K) have essentially similar effects on rat brain isolated mitochondria. The results are significant in view of the fact that α‐synucleinopathy is involved in the pathogenesis of Parkinson's disease.
Middle HoloceneBisondiet and mobility in the eastern Great Plains (USA) based onδ13C,δ18O, and87Sr/86Sr analyses of tooth enamel carbonate
Authors: Widga Chris , Walker J. Douglas , Stockli Lisa D.
Published: March 2010

During the Holocene, bison (Bison bison)were key components of the Great Plains landscape. This study utilizes serial stable isotope analyses (tooth enamel carbonate) of 29 individuals from five middle Holocene (∽ 7–8.5·ka) archaeological sites to address seasonal variability in movement patterns and grazing behavior of bison populations in the eastern Great Plains. Stable carbon isotopes (δ13C) indicate a bison diet that is similar to the C3/C4 composition of modern tallgrass prairies, while87Sr/86Sr values generally indicate very little seasonal movement (b50 km) and relatively limited inter-annual movement (b500 km) over the course of 4–5 yr. Analyses of variability in serial stable oxygen isotope samples (δ18O) further substantiate a model of localized bison herds that adhered to upland areas of the eastern Plains and prairie–forest border.
Treatment of a cochlear implant biofilm infection: a potential role for alternative antimicrobial agents
Authors: Brady A J , Farnan T B , Toner J G , Gilpin D F , Tunney M M
Published: March 2010

Objective:

This study aimed to investigate antimicrobial treatment of an infected cochlear implant, undertaken in an attempt to salvage the infected device.

Methods:

We used the broth microdilution method to assess the susceptibility of meticillin-sensitive Staphylococcus aureus isolate, cultured from an infected cochlear implant, to common antimicrobial agents as well as to novel agents such as tea tree oil. To better simulate in vivo conditions, where bacteria grow as microcolonies encased in glycocalyx, the bactericidal activity of selected antimicrobial agents against the isolate growing in biofilm were also compared.

Results:

When grown planktonically, the S aureus isolate was susceptible to 17 of the 18 antimicrobials tested. However, when grown in biofilm, it was resistant to all conventional antimicrobials. In contrast, 5 per cent tea tree oil completely eradicated the biofilm following exposure for 1 hour.

Conclusion:

Treatment of infected cochlear implants with novel agents such as tea tree oil could significantly improve salvage outcome.
Melioidosis and the vacuum-assisted closure device: a rare cause of a discharging neck wound, and a new approach to management
Authors: Garas G , Ifeacho S , Millard R , Tolley N
Published: March 2010

Objective:

We report a case of melioidosis presenting as a discharging neck abscess, and we describe the use of a vacuum-assisted closure device in its management.

Method:

We report the case of a 44-year-old, Afro-Caribbean woman with melioidosis. We also present the results of a literature search using the search terms ‘melioidosis’, ‘Burkholderia pseudomallei’ and ‘vacuum-assisted closure device’.

Results:

Microbiological analysis identified the causative organism as being the bacteriumBurkholderia pseudomallei, and its antimicrobial sensitivities to imipenem and ciprofloxacin. A vacuum-assisted closure device was used to manage the patient's melioidosis of the neck; we believe this is the first report of such treatment.

Conclusions:

Melioidosis is rare in the UK and western world; however, exposure can occur during travel to endemic areas. We therefore draw attention to this infection as part of the differential diagnosis of a neck abscess. We propose the use of vacuum-assisted closure devices as useful adjuncts to the management of discharging neck wounds.
On the drag force on non-spherical dust grain
Authors: KRASHENINNIKOV S. I. , MENDIS D. A.
Published: March 2010

It is shown that the direction of the drag force imposed on non-spherical grain by plasma flow is not necessarily aligned with the flow velocity. The implications of this fact for a grain dynamics are discussed.
Neural correlates of visuospatial working memory in the ‘at-risk mental state’
Authors: Broome M. R. , Fusar-Poli P. , Matthiasson P. , Woolley J. B. , Valmaggia L. , Johns L. C. , Tabraham P. , Bramon E. , Williams S. C. R. , Brammer M. J. , Chitnis X. , Zelaya F. , McGuire P. K.
Published: March 2010

Background

Impaired spatial working memory (SWM) is a robust feature of schizophrenia and has been linked to the risk of developing psychosis in people with an at-risk mental state (ARMS). We used functional magnetic resonance imaging (fMRI) to examine the neural substrate of SWM in the ARMS and in patients who had just developed schizophrenia.

Method

fMRI was used to study 17 patients with an ARMS, 10 patients with a first episode of psychosis and 15 age-matched healthy comparison subjects. The blood oxygen level-dependent (BOLD) response was measured while subjects performed an object–location paired-associate memory task, with experimental manipulation of mnemonic load.

Results

In all groups, increasing mnemonic load was associated with activation in the medial frontal and medial posterior parietal cortex. Significant between-group differences in activation were evident in a cluster spanning the medial frontal cortex and right precuneus, with the ARMS groups showing less activation than controls but greater activation than first-episode psychosis (FEP) patients. These group differences were more evident at the most demanding levels of the task than at the easy level. In all groups, task performance improved with repetition of the conditions. However, there was a significant group difference in the response of the right precuneus across repeated trials, with an attenuation of activation in controls but increased activation in FEP and little change in the ARMS.

Conclusions

Abnormal neural activity in the medial frontal cortex and posterior parietal cortex during an SWM task may be a neural correlate of increased vulnerability to psychosis.
Language combinations, subtypes, and severity in the study of bilingual children with specific language impairment
Authors: Leonard Laurence B.
Published: March 2010

I commend Johanne Paradis not only for her interesting Keynote Article but also for the careful research that she has conducted along with her collaborators in the area of bilingual language development and disorders. Her contributions have been significant and are sure to shape our theoretical as well as clinical understanding of specific language impairment (SLI). In this Commentary, I focus on three issues. The first stems quite directly from ideas raised in the Keynote Article; the second and third deal with factors that we need to consider when conducting research involving comparison groups of bilingual and monolingual children with SLI.
Accounting for carbon in avoided degradation and reforestation programmes in Mediterranean forests
Authors: CAPARRÓS ALEJANDRO , OVANDO PAOLA , OVIEDO JOSÉ L. , CAMPOS PABLO
Published: March 2010

After reviewing the Kyoto Protocol rules for carbon sequestration accounting and the different carbon accounting methods proposed in the literature for forest management, for reforestation and, more recently, for avoided deforestation or degradation, we discuss possible carbon accounting rules for a post-Kyoto world. We then apply the results of this discussion to micro-applications in an Annex I country (Spain) and in a non-Annex I country (Tunisia), comparing avoided degradation with reforestation alternatives. In both areas we focus on Mediterranean forest, one of the world's hotspots of biodiversity. We calculate CO2break-even prices, including in the analysis not only commercial values, but also, where these are relevant, existing subsidies. We also investigate social preferences for avoided degradation and reforestation using stated preference methods. Our results support the convenience of a change in focus for European Union subsidies from reforestation to avoided degradation.
An equivalent viscoelastic model for rock mass with parallel joints
Authors: Li Jianchun , Ma Guowei , Zhao Jian
Published: March 2010

An equivalent viscoelastic medium model is proposed for rock mass with parallel joints. A concept of “virtual wave source (VWS)” is proposed to take into account the wave reflections between the joints. The equivalent model can be effectively applied to analyze longitudinal wave propagation through discontinuous media with parallel joints. Parameters in the equivalent viscoelastic model are derived analytically based on longitudinal wave propagation across a single rock joint. The proposed model is then verified by applying identical incident waves to the discontinuous and equivalent viscoelastic media at one end to compare the output waves at the other end. When the wavelength of the incident wave is sufficiently long compared to the joint spacing, the effect of the VWS on wave propagation in rock mass is prominent. The results from the equivalent viscoelastic medium model are very similar to those determined from the displacement discontinuity method. Frequency dependence and joint spacing effect on the equivalent viscoelastic model and the VWS method are discussed.
Major episodes in the geologic history of western Promethei Terra, Mars
Authors: Ivanov M. A. , Korteniemi J. , Kostama V‐P. , Raitala J. , Törmänen T. , Neukum G.
Published: March 2010

Geologic evolution of the western portion of Promethei Terra (40–50°S, 90–105°E) consists of two major episodes. The first was the formation of a late Noachian–early Hesperian volcanic province. During this episode a kilometer‐thick suite (≈0.3 × 106km3) of lavas accumulated to the south of Reull and Harmakhis Valles within a regional depression that probably was formed earlier in a massive erosion. A topographic barrier of the cratered terrains separates the volcanic western Promethei plateau from Hesperia Planum. Thus, the lavas could not originate from Hesperia Planum. The topographic position of western Promethei Terra excludes a possible lava feeding from Hadriaca Patera. Dikes from Tyrrhena Patera potentially could be the lava source. The massive erosion before formation of the lava plateau in western Promethei Terra is poorly consistent, however, with the hypothesis that the distal dikes served as the source and favors emplacement of sills or a local source for the lavas. The second episode after the lava plateau emplacement was surface modification by glacial, fluvial, and aeolian processes. The time of the episode is poorly known, and it could continue from the late Hesperian and through the entire Amazonian epoch. Mesas, channels, and esker‐like ridges suggest that at the earlier stages of this episode (late Hesperian–early Amazonian) a glacier or ice dust deposits covered the western Promethei Terra area studied. The 50–60 × 103km3formation could contain 15–18 to 40–50 × 103km3of ice. This is comparable with the ice involved into of lobate apron formation (5–13 × 103km3) at the later Amazonian stages of western Promethei Terra. Because of the uncertainties in the ice volume estimates, the total amount of water in the earlier glacier and later aprons was approximately the same.
A data brief on magnesium isotope compositions of marine calcareous sediments and ferromanganese nodules
Authors: Rose‐Koga Estelle F. , Albarède Francis
Published: March 2010

The magnesium isotope compositions of 26 ferromanganese nodules from various oceans and 22 calcareous sediment samples from Ocean Drilling Program (ODP) leg sites from the Atlantic (ODP704, leg 114) and the Pacific (ODP846, leg 138) have been analyzed by Multicollector–Inductively Coupled Plasma–Mass Spectrometer. Most nodules from the Pacific and Atlantic oceans have δ26Mg (between −1.89 ± 0.24 and −0.54 ± 0.01‰, 2σ) scatter around the average ocean water value of −0.86 ± 0.12‰. Indian Ocean nodules display a large variation in δ26Mg ranging from −2.94 ± 0.46 to +0.69 ± 0.18‰. As for calcareous sediments, δ26Mg variations range between −2.94 ± 0.50 and −0.71 ± 0.45‰ and between −4.00 ± 0.31 and −1.63 ± 0.09‰ for the Atlantic and the Pacific legs, respectively. This study allows the construction of a thread of global δ26Mg mapping in Fe‐Mn nodules and suggests that what controls the δ26Mg variations of marine calcareous sediments is complex and probably linked both to a mixture of different tests of micro‐organisms and to diagenesis.
Measurements and predictions of subsidence induced by soil consolidation using persistent scatterer InSAR and a hyperbolic model
Authors: Kim Sang‐Wan , Wdowinski Shimon , Dixon Timothy H. , Amelung Falk , Kim Jeong Woo , Won Joong‐Sun
Published: March 2010

A space‐borne SAR interferometric technique is presented for measuring and predicting ground subsidence associated with soil consolidation. Instead of a conventional constant velocity model, a hyperbolic model is introduced for persistent scatterer SAR interferometry (PSI) processing. Twenty three JERS‐1 SAR acquired between 1992 and 1998 were used to measure land subsidence in Mokpo city, Korea which had been primarily built on land reclaimed from the sea. Two subsidence field maps were derived and compared: a constant velocity model and a hyperbolic model. Non‐linear components depending on the stage of soil consolidation are well represented by the hyperbolic model. The maximum subsidence velocity reaches over 6 cm/yr, while the maximum acceleration is about −0.3 to −0.4 cm/year2. The predicted subsidence rate with the new model was validated by using later ENVISAT SAR data for 2004–2005. Prediction accuracy with the non‐linear model is improved significantly, indicating the importance of a physically‐based deformation model.
Observations of the velocity profile of a fast and deep oceanic density current constrained in a gully
Authors: Sherwin Toby J.
Published: March 2010

The southwestern side of the Wyville Thomson Ridge transports cold Faroe‐Shetland Channel Bottom Water in a narrow cascade from a depth of 500 m down to 1700 m. An upward looking acoustic Doppler current profiler located at a depth of 1200 m measured its currents to a height of 500 m for 6 months. The westward flowing deep density current (mean thickness 343 m) extended well above the bottom Ekman layer (of order 20 m) and had a profile with a bullet nose shape that had a peak velocity at a height that was about of its thickness. The mean maximum speed was about 60 cm s−1, although there was significant variability in velocity with 90% of the variance explained by mode 1 that had a similar bullet nose shape. From the downstream momentum balance it is estimated that the vertical eddy viscosity in the overflow was of order 0.5 m2 s−1 through most of its depth but somewhat larger near the interface. A full description of the velocity profile requires an opposing surface slope and current, with zero net pressure gradient within the overflow. The transverse circulation (mean speed ∼3 cm s−1) had southward flows at the interface and seabed and a return flow at middepth. This circulation is driven by imbalances between Coriolis forcing from the downstream current and the transverse pressure gradient. Its overturning scales suggest a bulk eddy viscosity of order 2 m2 s−1 and may indicate a feedback between the downstream and transverse currents.