bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self‐Sensitized Photooxygenation of a C60–Cycloheptatriene Dyad to Form Norcaradiene‐Derived Endoperoxides
Authors: Hanamura Masaaki , Kamada Jun , Amano Akiyo , Takeuchi Ken'ichi , Okazaki Takao , Hirai Katsuyuki , Kitagawa Toshikazu 
Published: May 2010

AbstractThe [60]fullerene–cycloheptatriene dyad 1 readily underwent [4+2] cycloaddition of molecular oxygen at the cycloheptatriene moiety to give endoperoxides 5‐exo and 5‐endo. The involvement of singlet oxygen was verified by the complete inhibition of oxygenation on addition of 1,4‐diazabicyclo[2.2.2]octane (DABCO), which is an efficient singlet‐oxygen quencher. The observed facile oxygenation was attributed to both the strong photosensitizing ability of the fullerene cage and to the valence isomerization of 1 to the norcaradiene form, which was facilitated by the bulky tert‐butyl groups. Competitive oxygenation of 1 and a related cycloheptatriene lacking the fullerenyl group (2) resulted in the formation of endoperoxides of the two molecules in comparable yields. This result demonstrates that the cycloaddition is not an in‐cage reaction but occurs after the singlet oxygen has diffused from the solvent cage.
Concise Synthesis of the Unnatural Sphingosine and Psychosine Enantiomer
Authors: Parameswar Archana R. , Hawkins Jacqueline A. , Mydock Laurel K. , Sands Mark S. , Demchenko Alexei V. 
Published: May 2010

AbstractThe accumulation of psychosine (galactosyl sphingosine) has been associated with the pathogenesis of Krabbe disease; however, the exact mechanism of its cytotoxicity remains unclear. Herein, we describe the synthesis of the unnatural enantiomer of erythro‐sphingosine, psychosine, and related derivatives thereof that would allow for the mechanistic elucidation of the toxicity of psychosine.
Towards Selective Recognition of Sialic Acid Through Simultaneous Binding to Its cis‐Diol and Carboxylate Functions
Authors: Regueiro‐Figueroa Martín , Djanashvili Kristina , Esteban‐Gómez David , de Blas Andrés , Platas‐Iglesias Carlos , Rodríguez‐Blas Teresa 
Published: May 2010

AbstractA series of receptors containing phenylboronic acid and urea or thiourea units have been designed for simultaneous recognition of the cis‐diol and carboxylate functions of sialic acids, which are known to be overexpressed on the surfaces of tumor cells. The interaction of the receptors with 5‐acetylneuraminic acid (Neu5Ac) and 2‐α‐O‐methyl Neu5Ac (MeNeu5Ac) in DMSO solution has been investigated bymeans of spectrophotometric titrations and 1H, 13C, and 11B NMR spectroscopy. Additionally, we have also investigated the binding of these receptors with competing monosaccharides such as D‐(+)‐glucose, D‐fructose, methyl α‐D‐galactoside, and methyl α‐D‐mannoside. Our results show that 2‐{[3‐(4‐nitrophenyl)thioureido]methyl}phenylboronic acid (3a) recognizes both Neu5Ac and MeNeu5Ac with good selectivity with regard to the remaining monosaccharides investigated. DFT calculations performed at the B3LYP/6‐31G(d) level show that this selectivity is due to a cooperative two‐site binding of Neu5Ac through 1) ester formation by interaction at the phenylboronic acid function of the receptor and 2) hydrogen‐bond interaction between the thiourea moiety and the carboxylate group of Neu5Ac. Compound 3a can therefore be considered a promising synthon for the design of contrast agents for magnetic resonance imaging of tumors. In contrast, the analogue of 3a containing a urea moiety – compound 3b – displays strong binding to all monosaccharides investigated, due to two‐site binding through interaction on the phenylboronic acid function of the receptor and a hydrogen‐bond interaction between the urea moiety and the sugar hydroxy groups.
Investigation and modeling of cesium(I) adsorption by Turkish clays: Bentonite, zeolite, sepiolite, and kaolinite
Authors: Bayülken Seval , Başçetin Elvan , Güçlü Kubilay , Apak Reşat 
Published: May 2010

AbstractThe cesium ion adsorption by Turkish clays, i.e., bentonite, zeolite, sepiolite, and kaolinite, was investigated as a function of Cs+ concentration, pH, time, and temperature using the Cs‐137 radiotracer method. The analysis of some major and minor components of clays was performed with ED‐XRF. Bentonite was shown to exhibit the highest capacity and sorption affinity toward Cs. The best fits for adsorption isotherms were with Freundlich and D‐R models. The second order rate constant of cesium sorption was highest for kaolinite among the clays. Cesium adsorption proceeded essentially by ion exchange and partly by specific adsorption mechanisms. The results showed that especially bentonite and zeolite can be used as effective barrier materials for sorptive hindrance of an expanding Cs radioisotope plume. © 2010 American Institute of Chemical Engineers Environ Prog, 2011
Psychological distress and risk for eating disorders in subgroups of dieters
Authors: Rasmus Isomaa , Anna‐Lisa Isomaa , Mauri Marttunen , Riittakerttu Kaltiala‐Heino , Kaj Björkqvist 
Published: May 2010

AbstractObjectiveThe aim of the present study was to predict the risk of developing an eating disorder in subgroups of dieters, based on the adolescents own accounts of the reason for starting to diet.MethodEighty‐one dieters from a cohort of 595 adolescents (318 boys and 288 girls) aged 15 participated in the present prospective study. Personal interviews at both base‐line and follow‐up were combined with questionnaire data on depression, social phobia and self‐esteem.ResultsFour mutually exclusive groups of dieters were identified: vanity dieters, overweight dieters, depressed dieters and feeling fat dieters. Depressed and feeling‐fat dieters had a 15‐fold risk of having a lifetime eating disorder at age 18 compared to vanity and overweight dieters.ConclusionTypical teenage vanity dieting and dieting among overweight adolescents appears to be a benign practice, but adolescents dieting because of psychological distress have high‐risk of developing an eating disorder. Copyright © 2010 John Wiley & Sons, Ltd and Eating Disorders Association.
A physiologically based toxicokinetic model for methylmercury in female American kestrels
Authors: Nichols John W. , Bennett Richard S. , Rossmann Ronald , French John B. , Sappington Keith G. 
Published: May 2010

Abstract
A physiologically based toxicokinetic (PBTK) model was developed to describe the uptake, distribution, and elimination of methylmercury (CH3Hg) in female American kestrels. The model consists of six tissue compartments corresponding to the brain, liver, kidney, gut, red blood cells, and remaining carcass. Additional compartments describe the elimination of CH3Hg to eggs and growing feathers. Dietary uptake of CH3Hg was modeled as a diffusion-limited process, and the distribution of CH3Hg among compartments was assumed to be mediated by the flow of blood plasma. To the extent possible, model parameters were developed using information from American kestrels. Additional parameters were based on measured values for closely related species and allometric relationships for birds. The model was calibrated using data from dietary dosing studies with American kestrels. Good agreement between model simulations and measured CH3Hg concentrations in blood and tissues during the loading phase of these studies was obtained by fitting model parameters that control dietary uptake of CH3Hg and possible hepatic demethylation. Modeled results tended to underestimate the observed effect of egg production on circulating levels of CH3Hg. In general, however, simulations were consistent with observed patterns of CH3Hg uptake and elimination in birds, including the dominant role of feather molt. This model could be used to extrapolate CH3Hg kinetics from American kestrels to other bird species by appropriate reassignment of parameter values. Alternatively, when combined with a bioenergetics-based description, the model could be used to simulate CH3Hg kinetics in a long-term environmental exposure. Environ. Toxicol. Chem. 2010; 29:1854–1867. © 2010 SETAC
Cadmium toxicity on the freshwater microalga Chlamydomonas moewusii Gerloff: Biosynthesis of thiol compounds
Authors: Suárez Cristina , Torres Enrique , Pérez-Rama Mónica , Herrero Concepción , Abalde Julio 
Published: May 2010

Abstract
Cadmium (Cd) toxicity and production of different thiols (phytochelatins, glutathione, γ-Glu-Cys and cysteine) were studied in the microalga Chlamydomonas moewusii exposed to different concentrations of this metal (1, 2, 4, 6, 8, and 10 mg/L) for 96 h. The inhibitory effect of Cd on growth was demonstrated. The value of EC50 (metal concentration which reduces the population growth to 50% of the control) obtained for this microalga was estimated at 4.1 ± 0.8 mg/L of Cd after 96 h of exposure. The amount of thiol compounds synthesized by C. moewusii changed with Cd concentration. Cysteine concentrations were significantly higher compared to those of γ-Glu-Cys and glutathione in all the Cd concentrations assayed. The amino acid cysteine reached its higher levels in those cultures in which a decrease in the concentration of phytochelatins (PCs) was observed. Both cysteine and glutathione concentrations showed significant differences along the Cd concentrations assayed, while the amount of γ-Glu-Cys detected remained stable. The PCs detected were of two, three, and four subunits. The level of PC2 was higher than that of PC3 and PC4. PC4 was detected only in the cultures exposed to the Cd concentrations of 1 and 2 mg/L, in which the synthesis of phytochelatins was higher. A rapid increase in the production of PC2 and PC3 was observed up to a Cd concentration of 2 mg/L, after which their levels began to decrease. Phytochelatins were not detected in cultures without Cd (controls) and in those exposed to the maximum Cd concentration (10 mg/L), in which cell growth was completely inhibited. Environ. Toxicol. Chem. 2010;29:2009–2015. © 2010 SETAC
Efficient quadrature and node positioning for exotic option valuation
Authors: Chung San‐Lin , Ko Kunyi , Shackleton Mark B. , Yeh Chung‐Ying 
Published: May 2010

AbstractWe combine the best features of two highly successful quadrature option pricing streams, improving the linked issues of numerical precision and abscissa positioning. Coupling the recombining abscissa (node) approach used in Andricopoulos, A., Widdicks, M., Duck, P., and Newton, D.P. (2003) (AWDN as well as AWND, 2007) with the Gauss‐Legendre Quadrature (GQ) method of Sullivan, M.A. (2000) yields highly accurate and efficient option prices for a range of standard and exotic specifications including barrier options and in particular for NGARCH, CEV, and jump‐diffusion processes. The improvements are due to manner in which GQ positions nodes and the use of these values without interpolation. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark
The performance of VIX option pricing models: Empirical evidence beyond simulation
Authors: Wang Zhiguang , Daigler Robert T. 
Published: May 2010

AbstractWe examine the pricing performance of VIX option models. Such models possess a wide‐range of underlying characteristics regarding the behavior of both the S&P500 index and the underlying VIX. Our tests employ three representative models for VIX options: Whaley (1993), Grunbichler and Longstaff (1996), Carr and Lee (2007), Lin and Chang (2009), who test four stochastic volatility models, as well as to previous simulation results of VIX option models. We find that no model has small pricing errors over the entire range of strike prices and times to expiration. In particular, out‐of‐the‐money VIX options are difficult to price, with Grunbichler and Longstaff's mean‐reverting model producing the smallest dollar errors in this category. Whaley's Black‐like option model produces the best results for in‐the‐money VIX options. However, the Whaley model does under/overprice out‐of‐the‐money call/put VIX options, which is opposite the behavior of stock index option pricing models. VIX options exhibit a volatility skew opposite the skew of index options. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark31:251–281, 2011
∼1.6 Ga ultrahigh‐temperature granulite metamorphism in the Central Indian Tectonic Zone: insights from metamorphic reaction history, geothermobarometry and monazite chemical ages
Authors: Bhandari Anubha , Chandra Pant Naresh , Bhowmik Santanu Kumar , Goswami Sriparna 
Published: May 2010

AbstractIn this study, we present precise pressure–temperature (P–T) and age constraints of ultrahigh‐temperature (UHT) metamorphism of the Bhandara–Balaghat granulite (BBG) domain at the southern margin of the Central Indian Tectonic Zone (CITZ). Supracrustal and metaigneous granulites of this domain, which lie as detached pods and lenses of various sizes within felsic gneiss–migmatite association record protracted high‐Tcrustal anatexis events, broadly synchronous with and/or punctuated with felsic and mafic plutonism. Magnesian metagreywacke protolith of the supracrustal suite records extensive biotite melting and subsequent melt extractions at deep crustal, UHT metamorphic conditions (T ≥ ∼900°C atP∼8 kbar), producing restitic mineral assemblages of garnet + rutile, garnet + cordierite and garnet + aluminous orthopyroxene. The diversity of the mineral assemblages is related to the domainal‐scale variation of the bulk rock composition.In situchemical age dating of five monazite grains, which occur in the different textural settings of the garnet + cordierite + orthopyroxene + rutile‐bearing granulite reveals two age domains: (1) Pervasive ∼1.6 Ga domain, which is recorded in monazites occurring as inclusions in garnet and in the leucosome matrix is correlated with the timing of the UHT metamorphism. (2) ∼1.47 Ga domain reflects a fluid‐mediated recrystallization event leading to dissolution and re‐precipitation of older monazite. The ∼1.6 Ga monazite chemical ages provide robust constraints on the timing of the earliest stage of tectonothermal processes in the CITZ (defined here as the ‘Central Indian Orogeny’). The significance of the ∼1.6 Ga hot orogenesis in interorogen correlation is discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Impact of Geese on the Limnology of Lakes and Ponds from Bylot Island (Nunavut, Canada)
Authors: Côté Ghislain , Pienitz Reinhard , Velle Gaute , Wang Xiaowa 
Published: May 2010

AbstractArctic freshwater ecosystems are important habitats for northern wildlife. Arctic climate impact studies suggest that global change could result in major modifications and perturbations of lakes, ponds and wildlife. Most studies focus either on freshwater ecosystems or on animal populations, but few have investigated the links that exist between them. Animal populations have the potential to alter the nutrient inputs in lakes and ponds via faeces. The present study is the first to reveal the impact of an expanding Greater Snow Goose (Chen caerulescens atlantica) population on the limnology of arctic lakes and ponds. A survey of 27 freshwater ecosystems was performed on Bylot Island (Nunavut, Canada) in order to identify patterns in limnological conditions. Using a multivariate statistical approach, our study shows that the presence of birds in the catchment of lakes and ponds has an impact on their nutrient status. Concentrations of major ions that were related to the distance from the sea were the main environmental variable explaining the limnological differences observed among lakes and ponds. Nutrient variables that were mostly related to the presence of Snow Geese played a secondary but significant role. N and P concentrations were different among impacted and non‐impacted sites, underlining the impact of animal populations on northern freshwater ecosystems. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Impact of Water Chemistry on Zooplankton Occurrence in Two Types (Field versus Forest) of Small Water Bodies
Authors: Kuczyńska‐Kippen Natalia , Joniak Tomasz 
Published: May 2010

AbstractWe examined the influence of water chemistry on zooplankton community structure in the unvegetated zone (open water) and among different types of macrophytes (helophytes and elodeids) in 12 ponds located in two types of catchment area (mid‐forest and mid‐field).An equal occurrence of rotifers and crustaceans was found in mid‐field ponds, while rotifers prevailed over crustaceans in mid‐forest ponds which may have been due to phytoflagellate prevalence, contributing to diminishing the diversity index.We found variation in physical‐chemical features between both types of ponds with higher trophic status, confirmed by eutrophy indicators (K. quadrata or B. longirwostris) frequent occurrence, in the case of mid‐field ponds. The type of water body (forest vs. field) was the best predictor of zooplankton species distribution using DCA analysis. Two groups of zooplankton species were distinguished: (1) related to the mid‐forest ponds (representatives of genera: Cephalodella, Lepadella, Lecane, Trichocerca), where zooplankton densities positively correlated with chlorophyll a and CDOC and (2) related to the mid‐field ponds (representatives of genera: Keratella, Bosmina or Ceriodaphnia).Spatial differentiation of zooplankton community structure was also recorded with lower species diversity attributed to the open water zone compared to vegetated areas. Crustacean densities rose along the heterogeneity gradient of a habitat (from the open water to the zone of elodeids), which indicates the best refuge conditions in the most complex habitat during the daylight‐hours in the ponds with fish presence. Rotifers (especially those equipped with morphological adaptations againt predators) remained in the open water despite the presence of fish. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spatial Distribution and Diversity of Macroinvertebrates on the Stony Shore of a Subarctic Lake
Authors: Klemetsen Anders , Elliott J. Malcolm 
Published: May 2010

AbstractQuantitative samples taken with a new colonisation sampler over three years demonstrated a macroinvertebrate community of 25 taxa in the stony littoral of Takvatn, North Norway. The spatial variance was density‐dependent and the ‘index of aggregation’ varied in the range 1.01–1.73 for 13 common taxa. The distribution was significantly aggregated for 10 taxa and close to random for three taxa. The taxon richness and diversity was lower than in southern oligotrophic Fennoscandian lakes but higher than in northern Swedish lakes. Takvatn had more Plecoptera and fewer Trichoptera than most other lakes. All Plecoptera and Ephemeroptera in the lake occur in northern Norwegian rivers and typically lotic species were prominent in the lake‐shore community. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temporal Dynamics of River Biofilm in Constant Flows: A Case Study in a Riverside Laboratory Flume
Authors: Boulêtreau Stéphanie , Sellali Mehdi , Elosegi Arturo , Nicaise Yvan , Bercovitz Yvan , Moulin Frédéric , Eiff Olivier , Sauvage Sabine , Sánchez‐Pérez José‐Miguel , Garabétian Frédéric 
Published: May 2010

AbstractA 15‐week experiment was performed in a riverside laboratory flume (with diverted river water) to check variations of river biofilm structure (biomass, algal and bacterial compositions) and function (community gross primary production GPP and respiration) under constant flow while water quality went through natural temporal variations. One major suspended matter pulse coinciding with one river flood was recorded after 10 weeks of experiment. Epilithic biofilm first exhibited a 10‐week typical pattern of biomass accrual reaching 33 g ash‐free dry matter (AFDM) m–2 and 487 mg chlorophyll‐a m–2 and then, experienced a shift to dominance of loss processes (loss of 60% AFDM and 80% chlorophyll‐a) coinciding with the main suspended matter pulse. Algal diversity remained low and constant during the experiment: Fragilaria capucina and Encyonema minutum always contribute over 80% of cell counts. DGGE banding patterns discriminated between two groups that corresponded to samples before and after biomass loss, indicating major changes in the bacterial community composition. GPP/R remained high during the experiment, suggesting that photoautotrophic metabolism prevailed and detachment was not autogenic (i.e., due to algal senescence or driven by heterotrophic processes within the biofilm). Observational results suggested that silt deposition into the biofilm matrix could have triggered biomass loss. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Developing a Benthic Index of Biological Integrity and Some Relationships to Environmental Factors in the Subtropical Xiangxi River, China
Authors: Li Fengqing , Cai Qinghua , Ye1 Lin 
Published: May 2010

AbstractThe aim of this study is to develop a benthic index of biotic integrity (B‐IBI) to help understand how the increasing anthropogenic pressure may impact the subtropical Xiangxi River in China. Benthic macroinvertebrate and environmental surveys were conducted at 77 sites in early summer 2004. Each collection site was categorized as reference or impaired based on physical, chemical, biological, and land‐use information. Six non‐redundant metrics from 35 metrics were used to differentiate between reference and impaired sites. We selected six metrics for the final IBI. The scoring criteria of each metric were normalized based on the quadrisection and 0–10 scaling systems. Both scaling methods were used to assess the aquatic health of each site in the Xiangxi River watershed. The results showed that most sites were in fairly poor condition. Furthermore, we identified the relationship between B‐IBI metrics, water‐quality, and land‐use variables with a principal component analysis. A composite of nutrients and land‐use intensity explained most variances. These results suggest that the B‐IBI may be a suitable method for assessing river conditions within the subtropical Xiangxi River in central China (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Calnuc: Emerging roles in calcium signaling and human diseases
Authors: Aradhyam Gopala Krishna , Balivada Lavanya Madhuri , Kanuru Madhavi , Vadivel Prabahar , Vidhya Balasubramanian Shanthi 
Published: May 2010

AbstractCalnuc is a recently discovered multidomain protein with EF‐hand calcium binding sites. Several studies have reported various interacting partners for calnuc and, therefore, also different sites of localization in the cell. It interacts with important molecules such as DNA, G protein, COX, and amyloid precursor protein among others in addition to being involved in stress response and trafficking. The immense possibilities (of various functions this protein might be involved in) implicate great future in medicine and physiology. Preliminary studies also implicate the possibility of calnuc being involved in some of the human diseases. These initial observations imply the functions that this protein might be involved in. This review emphasizes the importance of further research on this protein. © 2010 IUBMB IUBMB Life, 62(6): 440–450, 2010