bluuebunny/crossref_metadata_2025_split huggingface dataset:
“In‐Group Love” and “Out‐Group Hate” in Repeated Interaction Between Groups
Authors: Halevy Nir , Weisel Ori , Bornstein Gary 
Published: January 2011

ABSTRACTCostly individual participation in intergroup conflict can be motivated by “in‐group love”—a cooperative motivation to help the in‐group, by “out‐group hate”—an aggressive or competitive motivation to hurt the out‐group, or both. This study employed a recently developed game paradigm (Halevy, Bornstein, & Sagiv, 2008) designed specifically to distinguish between these two motives. The game was played repeatedly between two groups with three players in each group. In addition, we manipulated the payoff structure of the interaction that preceded the game such that half of the groups experienced peaceful coexistence and the other half experienced heightened conflict prior to the game. Enabling group members to express in‐group love independently of out‐group hate significantly reduced intergroup conflict. Group members strongly preferred to cooperate within their group, rather than to compete against the out‐group for relative standing, even in the condition in which the repeated game was preceded by conflict. Although both “in‐group love” and “out‐group hate” somewhat diminished as the game continued (as players became more selfish), choices indicative of the former motivation were significantly more frequent than choices indicative of the latter throughout the interaction. We discuss the implications of these findings for conflict resolution. Copyright © 2011 John Wiley & Sons, Ltd.
In Search of the Underlying Mechanism of the Disposition Effect
Authors: Lehenkari Mirjam 
Published: January 2011

ABSTRACTUsing comprehensive data from the Finnish stock market, we assess the explanatory value of the three most commonly cited explanations for the disposition effect: prospect theory, belief in mean reversion, and escalation of commitment. In general, the results provide evidence for the presence of the disposition effect. More importantly, the effect appears to be significantly more pronounced when investors are personally responsible for the initial investment decision. This finding suggests that investor behavior is influenced above all by self‐justificatory concerns, an interpretation that is consistent with the escalation of commitment‐based explanation of the disposition effect. Copyright © 2011 John Wiley & Sons, Ltd.
Negative appendicectomy and perforation rates in patients undergoing laparoscopic surgery for suspected appendicitis
Authors: Güller U , Rosella L , McCall J , Brügger L E , Candinas D 
Published: January 2011

AbstractBackgroundDespite widespread use of imaging technologies including ultrasonography and computed tomography, rates of negative appendicectomy and perforated appendicitis remain high. This trend analysis examined whether rates of negative appendicectomy and perforated appendicitis have decreased over time, and sought to evaluate clinical predictors associated with negative appendicectomy and perforated appendicitis.MethodsThis analysis was based on the prospective database of the Swiss Association of Laparoscopic and Thoracoscopic Surgery (SALTS). All patients aged 12 years and over undergoing emergency laparoscopic appendicectomy between 1995 and 2006 were included. Unadjusted and risk-adjusted logistic regression analyses were performed.ResultsA total of 7964 patients underwent laparoscopic appendicectomy, of whom 7452 (93·6 per cent) had acute appendicitis and 512 (6·4 per cent) had a macroscopically normal appendix. Perforation occurred in 1230 (16·5 per cent) of those with appendicitis. In multivariable analysis, younger age (12–18 years), female sex, absence of local or generalized peritonitis and an early point during the study period were significant predictors of negative appendicectomy. For perforated appendicitis, significant predictors included age over 36 years, presence of localized or generalized peritonitis, and high American Society of Anesthesiologists grade. The rate of negative appendicectomy decreased from 12·7 per cent in 1995 to 2·8 per cent in 2006, there being a significant reduction in both unadjusted and risk-adjusted analyses (P &lt; 0·001 for trend). In adjusted analyses, the rate of perforated appendicitis did not increase significantly over time.ConclusionThe rate of negative appendicectomy decreased over time, without an accompanying increase in perforated appendicitis. The risk of having a negative appendicectomy was highest in girls aged 12–18 years without local or generalized peritonitis during the early study period, whereas perforation was associated with age over 36 years, presence of localized or generalized peritonitis, and greater co-morbidity.
Polypeptide Conjugate Binders that Discriminate between Two Isoforms of Human Carbonic Anhydrase in Human Blood
Authors: Tegler Lotta T. , Fromell Karin , Jonsson Bengt‐Harald , Viljanen Johan , Winander Cecilia , Carlsson Jonas , Baltzer Lars 
Published: January 2011

AbstractTwo binder candidates 4‐C37L34‐B and 3‐C15L8‐B from a 16‐membered set of 42‐residue polypeptide conjugates designed to bind human carbonic anhydrase II (HCAII), were shown to bind HCAII with high affinity in a fluorescence‐based screening assay. Two carbonic anhydrase isoforms with 60 % homology exist in human blood with HCAI being present in five‐ to sevenfold excess over HCAII. The ability of the binders to discriminate between HCAI and HCAII was evaluated with regard to what selectivity could be achieved by the conjugation of polypeptides from a 16‐membered set to a small organic molecule that binds both isoforms with similar affinities. The polypeptide conjugate 4‐C37L34‐B bound HCAII with a KD of 17 nM and HCAI with a KD of 470 nM, that is, with a 30‐fold difference in affinity. The corresponding dissociation constants for the complexes formed from 3‐C15L8‐B and the two carbonic anhydrases were 60 and 390 nM, respectively. This demonstration of selectivity between two very similar proteins is striking in view of the fact that the molecular weight of each one of the conjugate molecules is little more than 5000, the fold is unordered, and the polypeptide sequences were designed de novo and have no prior relationship to carbonic anhydrases. The results suggest that synthetic polypeptide conjugates can be prepared from organic molecules that are considered to be weak binders with low selectivity, yielding conjugates with properties that make them attractive alternatives to biologically generated binders in biotechnology and biomedicine.
Minimal Substrate Features for Erm Methyltransferases Defined by Using a Combinatorial Oligonucleotide Library
Authors: Hansen Lykke H. , Lobedanz Sune , Douthwaite Stephen , Arar Khalil , Wengel Jesper , Kirpekar Finn , Vester Birte 
Published: January 2011

AbstractErm methyltransferases are prevalent in pathogenic bacteria and confer resistance to macrolide, lincosamide, and streptogramin B antibiotics by specifically methylating the 23S ribosomal RNA at nucleotide A2058. We have identified motifs within the rRNA substrate that are required for methylation by Erm. Substrate molecules were constructed in a combinatorial manner from two separate sets (top and bottom strands) of short RNA sequences. Modifications, including LNA monomers with locked sugar residues, were incorporated into the substrates to stabilize their structures. In functional substrates, the A2058 methylation target (on the 13‐ to 19‐nucleotide top strand) was displayed in an unpaired sequence immediately following a conserved irregular helix, and these are the specific structural features recognized by Erm. Erm methylation was enhanced by stabilizing the top‐strand conformation with an LNA residue at G2056. The bottom strand (nine to 19 nucleotides in length) was required for methylation and was still functional after extensive modification, including substitution with a DNA sequence. Although it remains possible that Erm makes some unspecific contact with the bottom strand, the main role played by the bottom strand appears to be in maintaining the conformation of the top strand. The addition of multiple LNA residues to the top strand impeded methylation; this indicates that the RNA substrate requires a certain amount of flexibility for accommodation into the active site of Erm. The combinatorial approach for identifying small but functional RNA substrates is a step towards making RNA–Erm complexes suitable for cocrystal determination, and for designing molecules that might block the substrate‐recognition site of the enzyme.
Characterization of the Biosynthesis Gene Cluster for Alkyl‐O‐Dihydrogeranyl‐Methoxyhydroquinones in Actinoplanes missouriensis
Authors: Awakawa Takayoshi , Fujita Nobuyuki , Hayakawa Masayuki , Ohnishi Yasuo , Horinouchi Sueharu 
Published: January 2011

AbstractA polyketide biosynthesis gene cluster (agq) was found on the genome of a rare actinomycete, Actinoplanes missouriensis. Streptomyces lividans expressing agqA encoding a type III polyketide synthase produced alkylresorcinols mainly from C16–17 fatty acids. Heterologous expression of the agq genes in S. lividans indicated the function of cognate polyketide modification enzymes; a monooxygenase AgqB hydroxylates the alkylresorcinols to yield 6‐alkyl‐2‐hydroxyhydroquinones, a methyltransferase AgqC catalyzes O‐methylation of the alkyl‐hydroxyhydroquinones to yield 6‐alkyl‐2‐methoxyhydroquinones, and a UbiA‐like prenyltransferase AgqD attaches a prenyl group to the C‐4 hydroxy group of the alkyl‐methoxyhydroquinones to yield 6‐alkyl‐4‐O‐geranyl‐2‐methoxyhydroquinones and 6‐alkyl‐4‐O‐dihydrofarnesyl‐2‐methoxyhydroquinones derived from C16–17 fatty acids. In contrast, A. missouriensis was found to produce 6‐alkyl‐4‐O‐dihydrogeranyl‐2‐methoxyhydroquinones derived from C16–18 fatty acids by the function of the agq gene cluster. All of these prenylated phenolic lipids were novel compounds.
Process Synthesis Principles in the Chromatographic Separation of Sugars from Biomass Hydrolysates
Authors: Saari P. , Hurme M. 
Published: January 2011

AbstractProcessing of biomass hydrolysates will increase in future as the sugar platform in biorefineries is employed to an increasing extent. Monosaccharides in the hydrolysates may be separated as a sugar group for fermentation or as individual sugars for use in the food and pharmaceutical industry. Chromatographic separation of sugars using ion exchange (IEX) resins is an interesting alternative for these purposes. The current status and use of IEX resins in the chromatographic separation of sugars is discussed. Based on industrial practice, process synthesis principles and heuristics are presented for the selection of a feasible IEX resin and separation sequence. Two case studies are presented and the viability of the synthesized sequences is verified experimentally.
Validation of Solids Suspension Viscosity Measurements Using Computational Fluid Dynamics
Authors: Dasari R. K. , Berson R. E. 
Published: January 2011

AbstractAccurately measuring the viscosity of a solids suspension requires uniform suspension of the solids in the viscometer cup. In a cup‐and‐impeller viscometer system, solids may settle when the impeller speed is too low, causing viscosity measurements to appear lower than that of a well‐suspended slurry. Pre‐mixing of a solids suspension is typically performed to achieve steady state prior to measurements. Data here shows that the measured viscosity values differ depending on the pre‐mixing speed, indicating that the solids are not properly suspended at all speeds. A commonly used cup‐and‐vane impeller system can be thought of as a mixing tank that should operate above the uniform‐suspension speed (USS), although determining the USS experimentally is rather subjective. Computational fluid dynamics (CFD) is employed here to determine the USS of a pretreated corn stover (PCS) solids suspension and to confirm the experimentally measured USS.
Flow Regime Identification in a Bubble Column via Nuclear Gauge Densitometry and Chaos Analysis
Authors: Nedeltchev S. , Shaikh A. , Al‐Dahhan M. 
Published: January 2011

AbstractThe bubble column performance can change significantly as a result of flow regime change. Since reactor volume productivity, mass and heat transfer as well as mixing are affected by the prevailing flow regime, it is very important to know how to identify it. In this work, flow regime identification was performed on the basis of the Kolmogorov entropy (KE) algorithm applied to nuclear gauge densitometry data. In addition, the average cycle time was used for validation of the results. Three transition velocities were identified that delineated the boundaries of the three main hydrodynamic regimes. The first two transition points were also confirmed by the information entropy concept. The increasing KE trend in the bubbly flow regime and the decreasing KE trend in the churn‐turbulent regime were predicted successfully by means of new semi‐theoretical models.
Deoxygenation of Methanol over ZSM‐5 in a High‐Pressure Catalytic Pyroprobe
Authors: Gunawardena D. A. , Fernando S. D. 
Published: January 2011

AbstractDeoxygenation is a critical step in making hydrocarbon‐rich biofuels from biomass constituents. Although the thermal effects of oxygenate aromatization have been widely reported, the effect of pressure on this critical reaction has not yet been closely investigated, one primary reason being the unavailability of a reactor that can pyrolyze oxygenates, especially those in solid form, under pressurized conditions. Here, the first of a series of studies on how oxygenates behave when catalytically pyrolyzed under elevated pressure and temperature conditions is reported. Methanol, the simplest alcohol, was selected as the candidate to study the chemical phenomena that occur under pressurized catalytic pyrolysis. The reactions were carried out over the shape‐selective catalyst ZSM‐5 (SiO2/Al2O3 = 30) under varying pressure (0 to 2.0684 MPa (300 psi) in 0.3447 MPa (50 psi) increments) and temperature (500 to 800 °C in 50 °C increments) conditions. Benzene, toluene, ethyl benzene, and xylenes (BTEX) were analyzed as the deoxygenated products of the reaction. The results indicate that the reactor pressure significantly affects deoxygenated product composition.
One‐Photon Photophysics and Two‐Photon Absorption of 4‐[9,9‐Di(2‐ethylhexyl)‐7‐diphenylaminofluoren‐2‐yl]‐2,2′:6′,2′′‐terpyridine and Their Platinum Chloride Complexes
Authors: Ji Zhiqiang , Li Yunjing , Pritchett Timothy M. , Makarov Nikolay S. , Haley Joy E. , Li Zhongjing , Drobizhev Mikhail , Rebane Aleksander , Sun Wenfang 
Published: January 2011

AbstractThe synthesis, one‐photon photophysics and two‐photon absorption (2PA) of three dipolar D‐π‐A 4‐[9,9‐di(2‐ethylhexyl)‐7‐diphenylaminofluoren‐2‐yl]‐2,2′:6′,2′′‐terpyridine and their platinum chloride complexes with different linkers between the donor and acceptor are reported. All ligands exhibit 1π,π* transition in the UV and 1π,π*/1ICT (intramolecular charge transfer) transition in the visible regions, while the complexes display a lower‐energy 1π,π*/1CT (charge transfer) transition in the visible region in addition to the high‐energy 1π,π* transitions. All ligands and the complexes are emissive at room temperature and 77 K, with the emitting excited state assigned as the mixed 1π,π* and 1CT states at RT. Transient absorption from the ligands and the complexes were observed. 2PA was investigated for all ligands and complexes. The two‐photon absorption cross‐sections (σ2) of the complexes (600–2000 GM) measured by Z‐scan experiment are much larger than those of their corresponding ligands measured by the two‐photon induced fluorescence method. The ligand and the complex with the ethynylene linker show much stronger 2PA than those with the vinylene linker.
Surface‐Enhanced Raman Scattering of Single‐ and Few‐Layer Graphene by the Deposition of Gold Nanoparticles
Authors: Lee Jisook , Shim Sangdeok , Kim Bongsoo , Shin Hyeon Suk 
Published: January 2011

AbstractSurface‐enhanced Raman scattering (SERS) of graphene on a SiO2(300 nm)/Si substrate was investigated by depositing Au nanoparticles using thermal evaporation. This provided a maximum enhancement of 120 times for single‐layer graphene at 633 nm excitation. SERS spectra and scan images of single‐layer and few‐layer graphene were acquired. Single‐layer graphene provides much larger SERS enhancement compared to few‐layer graphene, while in single‐layer graphene the enhancement of the G band was larger than that of the 2D band. Furthermore, the D bands were identified in the SERS spectra; these bands were not observed in a normal Raman spectrum without Au deposition. Appearance of the D band is ascribed to the considerable SERS enhancement and not to an Au deposition‐induced defect. Lastly, SERS enhancement of graphene on a transparent glass substrate was compared with that on the SiO2(300 nm)/Si substrate to exclude enhancement by multiple reflections between the Si substrate and deposited Au nanoparticles. The contribution of multiple reflections to total enhancement on the SiO2(300 nm)/Si substrate was 1.6 times out of average SERS enhancement factor, 71 times.
Magnetoresistance in La0.5Sr0.5MnO2.5
Authors: Cortés‐Gil Raquel , Ruiz‐González M. Luisa , Alonso José M. , García‐Hernández Mar , Hernando Antonio , Vallet‐Regí María , González‐Calbet José M. 
Published: January 2011

AbstractResistance measurements indicate the presence of magnetoresistance in the La0.5Sr0.5MnO2.5 brownmillerite related compound. An 80 % of magnetoresistance is found at 75 K. In spite of the partial break‐up occurring at the 3D network of octahedra sharing corners, characteristic of the full oxygen content perovskite phase, the oxygen deficient compound exhibits complex magnetic and electric properties. Such behavior can be explained on the basis of ferromagnetic and metallic clusters randomly distributed at the octahedral layers separated from each other by an insulating antiferromagnetic matrix. AC susceptibility measurements suggest spin glass behavior at low temperature as a consequence of the competition between different magnetic interactions.
Synthesis, Crystal Structures and Magnetic Properties of MIICuII Chains (M=Mn and Co) with Sterically Hindered Alkyl‐Substituted Phenyloxamate Bridging Ligands
Authors: Ferrando‐Soria Jesús , Pardo Emilio , Ruiz‐García Rafael , Cano Joan , Lloret Francisco , Julve Miguel , Journaux Yves , Pasán Jorge , Ruiz‐Pérez Catalina 
Published: January 2011

AbstractA series of neutral oxamato‐bridged heterobimetallic chains of general formula [MCu(Lx)2(S)2]⋅p S⋅q H2O [p=0–1, q=0–2.5; L1=N‐2,6‐dimethylphenyloxamate, S=DMF with M=Mn (1 a) and Co (1 b); L2=N‐2,6‐diethylphenyloxamate, S=DMF with M=Mn (2 a) and Co (2 b) or S=DMSO with M=Mn (2 c) and Co (2 d); L3=N‐2,6‐diisopropylphenyloxamate, S=DMF with M=Mn (3 a) and Co (3 b) or S=DMSO with M=Mn (3 c) and Co (3 d)] were prepared by treating the corresponding anionic oxamatocopper(II) complexes [Cu(Lx)2]2− (x=1–3) with M2+ cations (M=Mn and Co) in DMF or DMSO as the solvent. The single‐crystal X‐ray structures of 2 a and 3 a reveal the occurrence of well‐isolated, zigzag, oxamato‐bridged manganese(II)–copper(II) chains. The intrachain Cu⋅⋅⋅Mn distances across the oxamato bridge are 5.3761(7) and 5.4002(17) Å for 2 a and 3 a, respectively, whereas the shortest interchain Mn⋅⋅⋅Mn distances are 9.4475(16) and 8.1649(14) Å for 2 a and 3 a, respectively. All of these MIICuII chains (M=Mn and Co) exhibit 1D ferrimagnetic behaviour with moderately strong intrachain antiferromagnetic coupling between the square‐planar CuII and octahedral high‐spin MII ions across the oxamato bridge [−J=31.4–35.2 and 33.4–44.8 cm−1, respectively; H=∑i−JSM,i(SCu,i+SCu,i−1)]. Only the CoIICuII chains show slow magnetic relaxation effects characteristic of single‐chain magnets (SCMs). Analysis of the magnetic relaxation dynamics of 3 d shows a thermally activated mechanism (Arrhenius law dependence) with values of the pre‐exponential factor (τ0=2.6×10−9 s) and activation energy (Ea=7.7 cm−1) that are typical of SCMs. In contrast, two relaxation regimes are observed for 2 d in different temperature regions (τ0=3.2×10−10 s and Ea=24.7 cm−1 for T<4.5 K and τ0=3.2×10−14 s and Ea=37.5 cm−1 for T>4.5 K).
Highly Efficient Multiphoton‐Absorbing Quadrupolar Oligomers for Frequency Upconversion
Authors: Feng Xin Jiang , Wu Po Lam , Li King Fai , Wong Man Shing , Cheah Kok Wai 
Published: January 2011

AbstractTwo series of quadrupolar diphenylamino‐endcapped oligofluorenes, PhN‐OF(n)‐NPh (n=2–5) and PhN‐OF(n)‐TAZ‐OF(n)‐NPh (n=1–4), which have an electron‐withdrawing 1,2,4‐triazole (TAZ) moiety as central core, with D–π–A–π–D structural motif (D=donor, A=acceptor), have been synthesized by palladium‐catalyzed Suzuki cross‐coupling of 9,9‐dibutyl‐7‐(diphenylamino)‐2‐fluorenylboronic acid and the corresponding (1,2,4‐triazole‐based) aryl halide as key step. On pumping with infrared femtosecond lasers, these oligomers showed very strong multiphoton‐excited blue photoluminescence. These D–π–D and D–π–A–π–D quadrupolar oligofluorenes exhibit superior three‐photon absorption properties compared to the respective D–π–A counterparts with a highest three‐photon absorption cross‐section (σ3) of up to 2.72×10−77 cm6 s2. Despite the comparable linear and multiphoton absorption properties of the two types of quadrupolar oligomers PhN‐OF(n)‐NPh and PhN‐OF(n)‐TAZ‐OF(n)‐NPh, only the former exhibit remarkably intense and highly efficient multiphoton‐excited frequency‐upconverted deep blue lasing, which gives rise to record high lasing efficiency of 0.097 % and very narrow of full width at half‐maximum of the lasing spectra. Our findings suggest that quadrupolar‐type molecules/oligomers are superior for multiphoton excited frequency upconverted lasing to their dipolar counterparts and also provide important guidelines to design highly efficient three‐photon absorption molecules for photoluminescence and lasing applications.
Kinetic Studies Exploring the Role of Anion Templation in the Slippage Formation of Rotaxane‐Like Structures
Authors: McConnell Anna J. , Beer Paul D. 
Published: January 2011

AbstractThe first examples of the slippage formation of rotaxane‐like structures in the presence of an anion template are reported between a macrocycle, synthesised by exploiting Eglinton coupling, and stoppered pyridinium axle components. The role of the anion template in the slippage process has been explored by kinetic studies. 1H NMR spectroscopic investigations reveal the slippage species formed are not rotaxanes but pseudorotaxanes with some rotaxane character. The anion template significantly influences the amount of rotaxane character and the rate of slippage. Importantly, the fastest slippage rates, kon, are achieved with the non‐coordinating hexafluorophosphate anion, whereas the slowest slippage off rates, koff, are observed in the presence of coordinating anions, such as chloride. Since the koff rates are significantly smaller than the kon rates in the presence of coordinating anions, these anions act as templates favouring formation of the slippage species thermodynamically. Consequently, the resulting pseudorotaxanes with coordinating anions have greater rotaxane character. Two strategies for converting the slippage pseudorotaxanes into rotaxanes using hydrogenation or complexation with cobalt carbonyl are investigated.