bluuebunny/crossref_metadata_2025_split huggingface dataset:
Xenopus laevis insulin receptor substrate IRS‐1 is important for eye development
Authors: Bugner Verena , Aurhammer Thomas , Kühl Michael 
Published: May 2011

AbstractExtracellular signal transduction into cells through ligand‐activated receptor tyrosine kinases, such as insulin‐like growth factor‐1 (IGF‐1) receptor (IGF‐1R) and insulin receptor (IR) is required for normal embryonic growth and development. The major mediators of IR and IGF‐1R are adaptor proteins of the insulin receptor substrate family, the best characterized member of which is IRS‐1. Insulin receptor substrate IRS‐1 has been shown to influence cell and body size and to interfere with differentiation. We have isolated IRS‐1 from Xenopus laevis embryos and analyzed for the first time its spatial and temporal expression pattern during embryogenesis. We found that Xenopus IRS‐1 is expressed maternally and constantly during embryogenesis. It is predominantly found in neural tissue at different stages. Furthermore, knock down of IRS‐1 in neural tissue by specific antisense morpholino oligonucleotides (MO) resulted in abnormal eye formation accompanied by reduction of the eye‐specific marker genes Rx1 and Pax6 and a decreased cell proliferation. Developmental Dynamics 240:1705–1715, 2011. © 2011 Wiley‐Liss, Inc.
Mucocutaneous candidiasis and autoimmunity against cytokines in APECED and thymoma patients: Clinical and pathogenetic implications
Authors: Kisand Kai , Lilic Desa , Casanova Jean‐Laurent , Peterson Pärt , Meager Anthony , Willcox Nick 
Published: May 2011

AbstractMuch has been learnt about the mechanisms of thymic self‐tolerance induction from work on both the rare autosomal recessive disease autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) and the autoimmune regulator (AIRE) protein mutated in this disease. Normally, AIRE drives low‐level expression of huge numbers of peripheral tissue‐specific antigens (TSAgs) in medullary thymic epithelial cells (mTECs), leading to the deletion of TSAg‐reactive thymocytes maturing nearby. The very recently discovered neutralizing autoantibodies (autoAbs) against Th17‐related cells and cytokines in two autoimmunity‐related syndromes associated with AIRE‐mutant thymi or AIRE‐deficient thymomas help to explain the chronic mucocutaneous candidiasis (CMC) seen in both syndromes. The surprising parallels between these syndromes also demand new hypotheses and research into the consequences of AIRE deficiency and the ensuing autoimmunizing pathways, and suggest more appropriate treatment regimens as discussed in this review.
Electron and Spin Density Topology of the H‐Cluster and Its Biomimetic Complexes
Authors: Giles Logan J. , Grigoropoulos Alexios , Szilagyi Robert K. 
Published: May 2011

AbstractThe catalytically active cluster of [FeFe]‐hydrogenase (H‐cluster) is unique due to its chemical composition and electronic and geometric structures. Protein crystallography revealed the presence of biologically unique diatomic ligands coordinating to the Fe centers and three light atoms bridging the sulfur atoms of its [2Fe]‐subcluster. The identity of the light atoms remains uncertain, even at close to atomic resolution (1.39 Å), as well as due to the lack of understanding at the molecular level of the cluster's biosynthetic pathway. By using all of the proposed ligand compositions, we carried out a comprehensive electronic structure analysis by evaluating the topology of the electron density and, particularly, the atomic spin density distribution derived from various population analysis methods for the free dithiolate ligands, the biomimetic [2Fe] complexes, and the entire H‐cluster embedded in its approximately 3.5 Å protein environment. In the biomimetic model complexes we found substantial spin density delocalization at the bridgehead of the dithiolate ligands. We attributed the presence of spin density to the through‐space spin polarization interaction between the paramagnetic iron centers and the bridgehead group, as represented by the ring critical points for the [Fe–(S–R–S)–Fe] metallacycles. However, this spin polarization of the bridgehead group vanishes for some of the biomimetic models, as well as for the 208‐atom computational model of the H‐cluster, due to a network of weak interactions. When the bridgehead group becomes part of a conduit for transmitting the spin polarization towards the terminal ends of each interaction network, such as the distal water or H‐bonded residues, the spin density vanishes. The variations of the Fe atomic spin densities were compared and contrasted for the proximal and distal iron sites in the crystallographic and the rotated conformations, respectively.
Dynamic viscosity of olive oil as a function of composition and temperature: A first approach
Authors: Bonnet Jean‐Philippe , Devesvre Laurie , Artaud Jacques , Moulin Philippe 
Published: May 2011

AbstractKnowledge of the viscosity of virgin olive oils (VOOs) is of great importance for the design of pilot plants, to determine the time required for the settling of particles at the end of the production chain and from a sensory view point. The dynamic viscosities of French VOOs from four different cultivars (‘Aglandau’, ‘Bouteillan’, ‘Salonenque’ and ‘Tanche’) were studied as a function of their fatty acid and TAG compositions and of the temperature [10–50°C]. These four VOOs had different TAG and fatty acid compositions representative of the range of compositional variations in the main French oils. Their viscosities were similar, although small but measurable differences that depended on their compositions were apparent. All the VOO samples exhibited the same dynamic viscosity pattern over temperature. For a given temperature, the viscosity difference was the greatest between Aglandau and Salonenque oils, Aglandau being the oil with the highest viscosity. The correlation between temperature and viscosity was highlighted by an Arrhenius model for this Newtonian fluid. The Arrhenius activation energy was correlated (R2 = 0.993) with the percentage of triolein, the main TAG in olive oil.
Strategies Based on Aryllithium and N‐Acyliminium Ion Cyclizations for the Stereocontrolled Synthesis of Alkaloids and Related Systems
Authors: Martínez‐Estibalez Unai , Gómez‐SanJuan Asier , García‐Calvo Oihane , Aranzamendi Eider , Lete Esther , Sotomayor Nuria 
Published: May 2011

AbstractThe intramolecular α‐amidoalkylation reactions of aromatic and heteroaromatic ring systems constitute a versatile approach for the synthesis of nitrogen heterocyles in a diastereoselective or enantioselective fashion. On the other hand, the intramolecular reactions of aryllithium compounds have also been extensively used in the synthesis of carbocycles and heterocycles. The use of imides as internal electrophiles is particularly attractive because of the potential to introduce diverse functionality into the cyclized products by subjecting the resulting α‐hydroxylactams to intermolecular reactions with nucleophiles through intermediate N‐acyliminium cations. This metalation/cyclization/α‐amidoalkylation sequence can be diastereocomplementary with intramolecular α‐amidoalkylation reactions via N‐acyliminium ions derived from the corresponding imides. This review focuses on recent developments of synthetic methods for heterocyclic systems (alkaloids and related systems) based on aryllithium compouns and N‐acyliminium ion cyclizations, with special attention to the stereocontrolled formation of carbon–carbon bonds.
C–H Bond Functionalization of Arylpyrimidines Catalyzed by an in situ Generated Ruthenium(II) Carboxylate System and the Construction of Tris(heteroaryl)‐Substituted Benzenes
Authors: Štefane Bogdan , Fabris Jan , Požgan Franc 
Published: May 2011

AbstractA ruthenium(II) carboxylate catalyst, generated in situ from [RuCl2(p‐cymene)]2 and 1‐phenyl‐1‐cyclopentanecarboxylic acid (PCCA) in the presence of K2CO3, allowed activation of the C–H bond in phenyl‐substituted pyrimidines and their direct functionalization with both electron‐deficient and electron‐rich aryl halides. The scope of this process can be extended to the use of heteroaryl bromides and less reactive aryl chlorides. This RuII‐PCCA complex constitutes a better catalytic system in comparison to other carboxylates.
Effects of near‐fault ground motions on the nonlinear dynamic response of base‐isolated r.c. framed buildings
Authors: Mazza Fabio , Vulcano Alfonso 
Published: May 2011

SUMMARYNear‐fault ground motions are characterized by long‐period horizontal pulses and high values of the ratio between the peak value of the vertical acceleration, PGAV, and the analogous value of the horizontal acceleration, PGAH, which can become critical for base‐isolated (BI) structures. The objective of the present work is to check the effectiveness of the base isolation of framed buildings when using High‐Damping‐Rubber Bearings (HDRBs), taking into consideration the combined effects of the horizontal and vertical components of near‐fault ground motions. To this end, a numerical investigation is carried out with reference to BI reinforced concrete buildings designed according to the European seismic code (Eurocode 8). The design of the test structures is carried out in a high‐risk region considering (besides the gravity loads) the horizontal seismic loads acting alone or in combination with the vertical ones and assuming different values of the ratio between the vertical and horizontal stiffnesses of the HDRBs. The nonlinear seismic analysis is performed using a step‐by‐step procedure based on a two‐parameter implicit integration scheme and an initial‐stress‐like iterative procedure. At each step of the analysis, plastic conditions are checked at the potential critical sections of the girders (i.e. end sections of the sub‐elements in which a girder is discretized) and columns (i.e. end sections), where a bilinear moment–curvature law is adopted; the effect of the axial load on the ultimate bending moment (M‐N interaction) of the columns is also taken into account. The response of an HDRB is simulated by a model with variable stiffness properties in the horizontal and vertical directions, depending on the axial force and lateral deformation, and linear viscous damping. Copyright © 2011 John Wiley & Sons, Ltd.
Short‐term versus medium‐term monitoring for detecting gully‐erosion variability in a Mediterranean environment
Authors: Marzolff Irene , Ries Johannes B. , Poesen Jean 
Published: May 2011

ABSTRACTThis study investigates how medium‐term gully‐development data differ from short‐term data, and which factors influence their spatial and temporal variability at nine selected actively retreating bank gullies situated in four Spanish basin landscapes. Small‐format aerial photographs using unmanned, remote‐controlled platforms were taken at the gully sites in short‐term intervals of one to two years over medium‐term periods of seven to 13 years and gully change during each period was determined using stereophotogrammetry and a geographic information system. Results show a high variability of annual gully retreat rates both between gullies and between observation periods. The mean linear headcut retreat rates range between 0·02 and 0·26 m a–1. Gully area loss was between 0·8 and 22 m² a–1 and gully volume loss between 0·5 to 100 m³ a–1, of which sidewall erosion may play a considerable part. A non‐linear relationship between catchment area and medium‐term gully headcut volume change was found for these gullies. The short‐term changes observed at the individual gullies show very high variability: on average, the maximum headcut volume change observed in 7–13 years was 14·3 times larger than the minimum change. Dependency on precipitation varies but is clearly higher for headcuts than sidewalls, especially in smaller and less disturbed catchments. The varying influences of land use and human activities with their positive or negative effects on runoff production and connectivity play a dominant role in these study areas, both for short‐term variability and medium‐term difference in gully development. The study proves the value of capturing spatially continuous, high‐resolution three‐dimensional data using small‐format aerial photography for detailed gully monitoring. Results confirm that short‐term data are not representative of longer‐term gully development and demonstrate the necessity for medium‐ to long‐term monitoring. However, short‐term data are still required to understand the processes – particularly human activity at varying time scales – causing fluctuations in gully erosion rates. Copyright © 2011 John Wiley & Sons, Ltd.
Carbon fluxes from eroding peatlands – the carbon benefit of revegetation following wildfire
Authors: Worrall F. , Rowson J. G. , Evans M. G. , Pawson R. , Daniels S. , Bonn A. 
Published: May 2011

ABSTRACTPeatlands are among the largest long‐term soil carbon stores, but their degradation can lead to significant carbon losses. This study considers the carbon budget of peat‐covered sites after restoration, following degradation by past wildfires. The study measured the carbon budget of eight sites: four restored‐revegetated sites, two unrestored bare soil control sites, and two intact vegetated controls over two years (2006–2008). The study considered the following flux pathways: dissolved organic carbon (DOC); particulate organic carbon (POC); dissolved carbon dioxide (CO2); primary productivity; net ecosystem respiration, and methane (CH4). The study shows that unrestored, bare peat sites can have significant carbon losses as high as 522 ± 3 tonnes C/km2/yr. Most sites showed improved carbon budgets (decreased source and/or increased sink of carbon) after restoration; this improvement was mainly in the form of a reduction in the size of the net carbon source, but for one restored site the measured carbon budget after four years of restoration was greater than observed for vegetated controls. The carbon sequestration benefit of peatland restoration would range between 122 and 833 tonnes C/km2/yr. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of ion‐slip current on the thermal instability of mixed connection in a boundary layer flow
Authors: Lin Ming‐Han 
Published: May 2011

SUMMARYEffect of ion‐slip current on the thermal instability in a boundary layer is studied. The criterion on the position marking the onset of longitudinal vortices is defined in the present paper. The results show that the onset position characterized by the Grashof number depends on the Prandtl number, the Reynolds number, the wave number, the Hall parameter, the ion‐slip parameter, and the Hartmann number. The flow becomes more stable as the magnetic field increases. However, the destabilizing effects are found on the flow when the Hall and ion‐slip currents are presented. The results of the present numerical prediction show reasonable agreement with the experimental data in the case of zero Hartmann number, ion‐slip parameter, and Hall parameter in the open literature. Copyright © 2011 John Wiley & Sons, Ltd.
How tight an embrace? Choosing the optimal degree of partner interaction in alliances based on risk, technology characteristics, and agreement provisions
Authors: Contractor Farok J. , Woodley James A. , Piepenbrink Anke 
Published: May 2011

AbstractThis study examines a key question one asks when negotiating an alliance: ‘how tight or loose a relationship do we wish to have with our partner?’ Interaction with one's partner is necessary in order to coordinate operations, effectively transfer tacit knowledge, monitor for opportunism, maximize joint synergistic value, and make sure that an appropriate share of the net benefit created by the alliance is appropriated by the technology provider. However, too tight an ‘embrace’ or too high a degree of interaction between the allies can increase coordination costs and increase the chance of unintended technology leakage. The sample, comprising 95 international alliances involving technology transfers, is grouped into four clusters with rising levels of interaction between allies. The optimal degree of interaction between the partners is explained by variables drawn from (1) technology characteristics and future technology policy, (2) coordination costs and risks, (3) agreement provisions, and (4) firm and sector characteristics that existed during the negotiation of the alliance. Using a proportional odds model, variables in the ‘coordination costs and risks’ and ‘agreement provisions’ categories found the most support in the results.
Form follows function? Interorganizational networks as a strategic imperative for global strategies
Authors: Parkhe Arvind 
Published: May 2011

AbstractP&G's global networks are the platform for the activities that, together, constitute the connect‐and‐develop strategy. (Huston and Sakkab,2006: 62).The main goal of any global strategy must be to manage the large differences that arise at borders, whether those borders are defined geographically or otherwise . . . Not all integration that is required to add value across borders needs to occur within a single organization. IBM and other firms illustrate that some externalization is a key part of most ambitious global strategies. (Ghemawat,2007: 67).
The strategic assembly of global firms: A microstructural analysis of local learning and global adaptation
Authors: Koza Mitchell P. , Tallman Stephen , Ataay Aylin 
Published: May 2011

AbstractStrategic assembly—the comprehensive and coordinated use of internal development, mergers, acquisitions, joint ventures, and alliances—is a novel approach to the construction and management of global firms. This article describes the role and characteristics of strategic assembly in the construction and management of the global multibusiness firm, an emerging form of global organization. We present a study of Group Renault and its relationship with two key players in the lucrative and emerging market for autos in Turkey, emphasizing the coevolutionary processes through which local players enter and dominate a local market and the global parent, utilizing local learning and organization, adapts to the global environment. We conclude with a call to action for research on the relationship between the strategic logic of global assemblers and the strategies of the firms at multiple levels of analysis.
The relationship between international diversification and firm performance: Why it remains a puzzle
Authors: Wiersema Margarethe F. , Bowen Harry P. 
Published: May 2011

AbstractDespite a wealth of empirical research, whether and how international diversification impacts firm performance remains one of the major unresolved research questions in the fields of strategy and international business. We propose that the lack of consensus about the nature of the international diversification–firm performance relationship results from a failure to fully grasp this complex phenomenon. Using data on trade flows of U.S. companies and their foreign subsidiaries, we provide a more focused and comprehensive perspective on the activities that define the geographic scope of U.S. companies that we hope will motivate a conceptualization of international diversification that encompasses the full range of activities that determine the geographic scope of a firm.
A theoretical assessment of the empirical literature on the impact of multinationality on performance
Authors: Hennart Jean‐François 
Published: May 2011

AbstractI assess the theoretical basis for the existence of a relationship between the size of a firm's foreign footprint (its multinationality) and its performance. I argue that multinationality results from a firm's choice between coordinating internally the stages of its value chain and letting them be organized on the market and hence that there are no reasons to expect net gains from an increase or a decrease in multinationality, the only profitability impact coming from a firm having made the wrong choice and being over‐ or under‐integrated compared to the optimum. I then show that the way the literature has operationalized multinationality does not match the theoretical arguments it has advanced. I conclude that a reassessment of the literature is overdue and point to some new directions.
Confocal laser endomicroscopy in gastrointestinal diseases
Authors: Goetz Martin , Watson Alastair , Kiesslich Ralf 
Published: May 2011

AbstractConfocal laser endomicroscopy (CLE) is a novel endoscopic technique permitting in vivo microscopy (optical biopsies) of the gastrointestinal mucosa. CLE has been studied in a multitude of diseases of the upper and lower gastrointestinal tract, including Barrett's esophagus, gastric inflammation and cancer, celiac disease, colorectal adenoma and carcinoma, and inflammatory bowel diseases. CLE has recently evolved and been studied for bile duct and liver imaging. CLE has shown overall high accuracy and enabled smart, targeted biopsies rather than untargeted sampling. Furthermore, the availability of real time microscopic information during endoscopy has immediate impact on therapeutic decisions and guides endoscopic interventions. CLE is also a unique tool for observation of (patho‐)physiologic events in their natural environment (functional imaging) and has been linked to molecular imaging of gastrointestinal neoplasia in vivo, thereby broadening our understanding of mucosal pathology in clinical and basic science. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Therapeutic leukapheresis in patients with leukostasis secondary to acute myelogenous leukemia
Authors: De Santis Gil Cunha , de Oliveira Luciana Correa Oliveira , Romano Lucas Gabriel Maltoni , Almeida Prado Benedito de Pina , Simoes Belinda Pinto , Rego Eduardo Magalhaes , Covas Dimas Tadeu , Falcao Roberto Passetto 
Published: May 2011

AbstractLeukostasis is a relatively uncommon but potentially catastrophic complication of acute myelogenous leukemia (AML). Prompt leukoreduction is considered imperative to reduce the high mortality rate in this condition. Leukapheresis, usually associated with chemotherapy, is an established approach to diminish blast cell counts. We report a single center experience in managing leukostasis with leukapheresis. Fifteen patients with leukostasis of 187 patients with AML (8.02%) followed at our institution were treated with leukapheresis associated with chemotherapy. The procedures were scheduled to be performed on a daily basis until clinical improvement was achieved and WBC counts were significantly reduced. Overall and early mortalities, defined as that occurred in the first 7 days from diagnosis, were reported. A high proportion of our patients with leukostasis (46.66%) had a monocytic subtype AML (M4/M5, according to French‐American‐British classification). The median overall survival was 10 days, despite a significant WBC reduction after the first apheresis procedure (from 200.7 × 109/L to 150.3 × 109/L). Almost half of patients (7/15) had an early death. Therapeutic leukapheresis, associated or not to chemotherapy, is an effective approach to reduce WBC counts in patients with AML and leukostasis; however, this therapeutic procedure does not appear to change significantly the sombre prognosis observed in the majority of patients with this complication. Other forms of treatment must be found to reduce the high mortality rate related to leukostasis. J. Clin. Apheresis, 2011. © 2011 Wiley‐Liss, Inc.
(Bromodimethylsulfonium) bromide–catalyzed one‐pot three‐component synthesis of imidazo[1,2‐a]pyridines
Authors: Venkatesham R. , Manjula A. , Rao B. Vittal 
Published: May 2011

Abstract(Bromodimethylsulfonium) bromide–catalyzed one‐pot multicomponent reaction of 2‐aminopyridine with aromatic aldehyde(s) and TMSCN yielding N‐benzylidene‐2‐phenylimidazo[1,2‐a]pyridines exclusively has been described. The reaction is solvent free, versatile, and takes significantly short time. J. Heterocyclic Chem., (2011).