bluuebunny/crossref_metadata_2025 huggingface dataset:
Positron Emission Tomography Combined With Computed Tomography as an Integral Component in Evaluation of Primary Cardiac Lymphoma
Authors: Lee Joseph C. , Platts David G. , Huang Yi‐Tung T. , Slaughter Richard E.
Published: May 2010

We present a case of primary cardiac lymphoma (PCL) that was initially manifest through syncopal episodes. In the diagnostic evaluation, positron emission tomography combined with computed tomography (PET‐CT) made a significant contribution—beyond that which would have been possible if only conventional imaging modalities such as magnetic resonance imaging (MRI) and transthoracic echocardiography (TTE) were utilized—and played a major role in follow‐up. Copyright © 2010 Wiley Periodicals, Inc.
Cardiac Epithelioid Leiomyosarcoma and the Role of Cardiac Imaging in the Differentiation of Intracardiac Masses
Authors: Jellis Christine , Doyle Joseph , Sutherland Tom , Gutman Jack , MacIsaac Andrew
Published: May 2010

Primary malignant cardiac neoplasms are extremely rare and can be difficult to differentiate from other intracardiac masses. We present a case of left atrial epithelioid leiomyosarcoma and review the imaging modalities available to diagnose and characterize intracardiac masses. We demonstrate how multimodal imaging aided diagnosis and proved crucial to establishing the tumor's location, degree of invasion, and involvement of surrounding structures prior to surgical resection. Copyright © 2010 Wiley Periodicals, Inc.
Asymptomatic Giant Left Atrium
Authors: Funk Michael , Perez Margarita , Santana Orlando
Published: May 2010

Giant left atria (GLA) is a condition where the left atrial diameter exceeds 65 mm.1 It is closely related to rheumatic mitral valve regurgitation or mixed mitral disease with predominant regurgitation and tends not to occur in patients with mitral regurgitation due to other causes.2 The majority of patients are symptomatic with the most common symptoms being that of shortness of breath, dysphagia, palpitations, chest pain, and thromboembolic events.3 Massive asymptomatic enlargement of the left atrium is a rare entity. We present such a case. Copyright © 2010 Wiley Periodicals, Inc.
Effects of Stem Cell Therapy on Left Ventricular Remodeling After Acute Myocardial Infarction: A Meta‐Analysis
Authors: Sun Lan , Zhang Tiantai , Lan Xi , Du Guanhua
Published: May 2010

Objectives

The objective was to perform a meta‐analysis of clinical trials that investigated the effects of stem cell therapy on left ventricular remodeling in patients after acute myocardial infarction (AMI).

Background

Intracoronary injection of stem cells in the acute phase of myocardial infarction has been proposed to replace the cardiomyocytes lost and to prevent deleterious pathological remodeling after myocardial infarction. Previously published trials have investigated the effects of cell therapy on left ventricular (LV) remodeling in AMI patients. However, the sample size of these studies is small and the conclusions are inconsistent.

Methods

Trials were identified in the Cochrane Library, EMBASE, and PubMed databases, reviews, and reference lists of relevant articles. The weighted mean difference (WMD) was calculated for net changes in LV end‐diastolic and end‐systolic volumes (LVEDV and LVESV) by using fixed‐effect models.

Results

A total of 11 trials (13 comparisons) with 832 participants evaluated the association between stem cell therapy and changes in LVEDV. Compared with the control group, stem cell therapy did not influence the LVEDV changes from baseline to follow‐up (WMD: − 1.76 mL, 95% confidence interval [CI]: − 4.61 to 1.08 mL, P = 0.233). A total of 9 trials (11 comparisons) with 797 participants evaluated the association between stem cell therapy and changes in LVESV. Compared with the control group, patients in the cell therapy group had a significantly greater reduction in LVESV from baseline to follow‐up (WMD: − 5.08 mL, 95% CI: − 7.80 to − 2.37 mL, P < 0.001).

Conclusion

This meta‐analysis suggests that cell therapy improves left ventricular contractility, but has no effect on LV remodeling. Copyright © 2010 Wiley Periodicals, Inc.
The Role of Fluorine Substitution in Biphenyl Methylene Imidazole‐Type CYP17 Inhibitors for the Treatment of Prostate Carcinoma
Authors: Hu Qingzhong , Negri Matthias , Olgen Sureyya , Hartmann Rolf W.
Published: May 2010

It has been established that the growth of most prostate carcinomas depends on androgen stimulation. The inhibition of cytochrome P450‐17 (CYP17) to block androgen biosynthesis is therefore regarded as a promising approach to therapy. Based on our previously identified lead compound Ref 1, a series of fluorine‐substituted biphenyl methylene imidazoles were designed, synthesized, and evaluated as CYP17 inhibitors to elucidate the influence of fluorine on in vitro and in vivo activity. It was found that meta‐fluoro substitution at the C ring improved activity, whereas ortho substitution decreased potency. Docking studies performed with our human CYP17 homology model suggest the presence of multipolar interactions between fluorine and Arg109, Lys231, His235, and Glu305. As expected, introduction of fluorine also prolonged the half‐life in plasma. The SARs obtained confirm the reliability of the protein model; compound 9 (IC50=131 nM) was identified as a strong CYP17 inhibitor, showing potent activity in rat, high bioavailability, and a long plasma half‐life: 12.8 h.
Energy efficient and QoS aware medium access control for wireless sensor networks
Authors: Yahya B. , Ben‐Othman J.
Published: May 2010

Enabling quality of service (QoS) applications over battery‐constrained wireless sensor networks (WSNs) poses significant challenges, because of the special characteristics of such networks. Developing real‐time applications for WSNs necessitates the development of new communication protocols capable of achieving application‐specific QoS and at the same time save energy. In this paper, we continue our previous work on developing and improving our EQ‐MAC protocol, which is designed specifically for WSNs to reduce energy consumption and provides QoS guarantees through the use of the service differentiation concept. The proposed protocol consists of two subprotocols: Classifier MAC (C‐MAC) and Channel Access MAC (CA‐MAC). C‐MAC is responsible of classifying gathered data at sensor nodes based on its importance. The CA‐MAC is an energy conserving medium access mechanism which uses a hybrid scheduling technique. CA‐MAC saves energy by differentiating between control and data messages. Data messages are assigned scheduled slots with no contention (here we have to emphasize that slots are assigned only to those nodes that have data to send, this allows an efficient energy use of the Time Division Multiple Access (TDMA) slots), whereas short periodic control messages are assigned random access slots. To study the performance of the EQ‐MAC protocol, we have conducted several simulation experiments on Network Simulator (NS‐2) to evaluate and compare the performance of our protocol against S‐MAC and Q‐MAC protocols. Simulation results demonstrate that EQ‐MAC outperforms the other two protocols and achieves a significant improvement in terms of the energy expenditure and delivery ratio. Under prioritized traffic, EQ‐MAC is comparable to Q‐MAC in average latency, while achieving less energy consumption. Copyright © 2010 John Wiley & Sons, Ltd.
A Mean Value Analysis approach to transaction performance evaluation of multi‐server systems
Authors: Cavendish D. , Koide H. , Oie Y. , Gerla M.
Published: May 2010

In this paper, we introduce a Mean Value Analysis (MVA)‐based methodology for the performance evaluation of transactions executed in a multi‐server distributed system. We first present probabilistic arguments to investigate under which conditions MVA models provide worst‐case response times, without large overshoots. Then, we show how to characterize the distributed server system so as to construct a model to predict response times as well as to estimate system capacity. Finally, we exemplify the methodology usage via transactions implemented in two distributed Linux systems. Copyright © 2010 John Wiley & Sons, Ltd.
Photocatalytic Oxidation of Phenolic Compounds by Using a Carbon Nanotube‐Titanium Dioxide Composite Catalyst
Authors: Silva Cláudia Gomes , Faria Joaquim Luís
Published: May 2010

A nanostructured multiwalled carbon nanotube (CNT) and titanium dioxide composite catalyst is prepared by a modified acid‐catalyzed sol–gel method. Pure anatase TiO2 and the CNT‐TiO2 composite are tested in the photocatalytic degradation of four para‐substituted phenols: 4‐chlorophenol, 4‐aminophenol, 4‐hydroxybenzoic acid and 4‐nitrophenol. The effect of several operational parameters on the photoefficiency of the composite catalyst is studied by using 4‐chlorophenol as model compound, namely catalyst loading, pH of the medium, hydrogen peroxide concentration, substrate concentration. A relationship between the Hammett constant of each para‐substituted phenolic compound and its degradability by the photocatalysts is found. The effect of the carbon phase in the catalyst is ascribed to its photosensitizer action. A clear beneficial effect is observed for the degradation of 4‐aminophenol and 4‐chlorophenol. For the molecules with stronger electron‐withdrawing (deactivating) groups, such as 4‐hydroxybenzoic acid and 4‐nitrophenol, no synergy effect is observed.
One‐Step Catalytic Transformation of Carbohydrates and Cellulosic Biomass to 2,5‐Dimethyltetrahydrofuran for Liquid Fuels
Authors: Yang Weiran , Sen Ayusman
Published: May 2010

Existing technologies to produce liquid fuels from biomass are typically energy‐intensive, multistep processes. Many of these processes use edible biomass as starting material. Carbohydrates, such as mono‐ and polysaccharides and cellulose, typically constitute 50–80 % of plant biomass. Herein, we report that hexose from a wide range of biomass‐derived carbohydrates, cellulose, and even raw lignocellulose (e.g., corn stover) can be converted into 2,5‐dimethyltetrahydrofuran (DMTHF) in one step, in good yields and under mild conditions in water. Under the same conditions, 2‐methyltetrahydrofuran is formed from pentose. The reaction employs a soluble rhodium catalyst, dihydrogen, and HI/HCl+NaI. The catalytic system is robust and can be recycled repeatedly without loss of activity. DMTHF is superior to ethanol and has many of the desirable properties currently found in typical petroleum‐derived transportation fuels.
Self‐Assembly of Palladium Nanoparticles on Periodic Mesoporous Organosilica Using an In Situ Reduction Approach: Catalysts for Ullmann Reactions in Water
Authors: Zhang Fang , Yin Jiewei , Chai Wei , Li HeXing
Published: May 2010

A SiH functionalized phenyl‐bridged periodic mesoporous organosilica [H‐PMO(Ph)] is synthesized via a surfactant‐directed assembly approach. Pd nanoparticles are then immobilized onto the PMO catalyst [Pd/H‐PMO(Ph)] by a SiH in situ reduction method. The Ullmann reaction, in water as medium, is used to investigate the catalytic performance of Pd/H‐PMO(Ph). The results show that the Pd/H‐PMO(Ph) catalyst has excellent catalytic activity and selectivity, which can be attributed to synergetic effects derived from the highly dispersed catalytic species and the hydrophobic microenvironments. Furthermore, the catalyst could be conveniently recovered and recycled five times without significant loss of activity and selectivity.
Good cell, bad cell: Flow cytometry reveals T‐cell subsets important in HIV disease
Authors: Chattopadhyay Pratip K. , Roederer Mario
Published: May 2010

Flow cytometry is a key technology in the study of HIV disease. In this article, we review various cellular markers that can be measured in the setting of pathogenesis or vaccination studies, including markers of activation, differentiation, senescence, immune suppression, and function. In addition, we discuss important considerations for making these measurements. Finally, we examine how flow cytometry studies have taught researchers about the disease process, and the potential for flow cytometry technology to guide treatment decisions and evaluate vaccine candidates in the future. Published 2010 Wiley‐Liss, Inc.
Localization of CD44 and CD90 positive cells to the invasive front of breast tumors
Authors: Donnenberg Vera S. , Donnenberg Albert D. , Zimmerlin Ludovic , Landreneau Rodney J. , Bhargava Rohit , Wetzel Ryan A. , Basse Per , Brufsky Adam M.
Published: May 2010

Background:

A variety of markers have been proposed to identify breast cancer stem cells. Here, we used immunohistostaining and flow cytometry to analyze their interrelationships and to sort cells for tumorigenicity studies.

Methods:

Cytokeratin, CD44, and CD90 were localized to primary breast cancer and normal breast (NB) tissue by immunohistostaining and related to CD117 and CD133 expression by flow cytometry. Immunodeficient NOD.CB17‐Prkdcscid/J and NOD.Cg‐Prkdcscid Il2rgtm1Wjl/SzJ mice were used to test tumorigenicity of sorted CD90+ low‐light scatter, CD90+ high‐light scatter, and CD90neg tumor cells.

Results:

NB basal cells coexpressed CD44 and CD90. As cells transited luminally, CD44 was retained and downmodulated, and CD90 was lost and cytokeratin increased. In breast tumors, basal‐like CD44+/CD90+ cells were localized to the tumor periphery, adjacent to CD90+ stroma. Like normal luminal cells, interior tumor cells were CD44+/CD90−. Immunophenotyping (CD44/CD90/CD117/CD133) of cytokeratin+ cells revealed no significant difference in expression between tumors and tumor‐free breast. In both, CD133 was distributed approximately equally among CD44/CD90 subsets, whereas CD117 expression was highest in the basal‐associated CD44+/CD90+ subset. Sorted CD90+ pleural effusion cells with lymphoid light scatter, 49% of which were CD44+, were uniquely tumorigenic in immunodeficient mice (100 cells/injection).

Conclusions:

Our data demonstrate that all tumors contain a small population of CD44+/CD90+ cells, mimicking the phenotype of ductal‐basal cells. These are localized to the tumor periphery, adjacent to CD90+ stroma. Among the nonhematopoietic, nonmesothelial cells found in metastatic pleural effusions, low‐light scatter CD90+ cells are most potently tumorigenic, compared to high‐scatter CD90+ cells and CD90− cells. © 2010 International Clinical Cytometry Society
Structural and Magnetic Studies of New NiII–LnIII Complexes
Authors: Costes Jean‐Pierre , Vendier Laure
Published: May 2010

The synthesis, structure determination and magnetic studies of dinuclear NiII–LnIII complexes (Ln = Y, La, Pr, Gd) involving ortho‐vanillin as the main ligand are described. Structural studies demonstrate that two types of complexes can be obtained with hexacoordinate Ni ions in slightly deformed octahedral environments and nine‐ or ten‐coordinate lanthanide ions. The Ni and Gd ions are linked by two phenoxo bridges in one complex and two phenoxo bridges and one nitrato bridge in the other. A ferromagnetic interaction operates in the Ni–Gd complex, with a D zero field splitting term for the nickel ion, as in the Ni–La and Ni–Y complexes where these D terms are the only active magnetic terms. Among the factors responsible for the different structures are ionic radii of the Ln ions, solvent and configuration change of the starting nickel complex; the role of solvent seems to be preponderant. The weak value of the ferromagnetic Ni–Gd interaction can be explained by the flexibility and the departure from planarity of the two independent ortho‐vanillin ligands.
Synthesis and Reactivity of an Unusual Ferrocenophane Bis(carbene complex)
Authors: Helten Holger , Beckmann Manuela , Schnakenburg Gregor , Streubel Rainer
Published: May 2010

Selective macrocyclization of 1,1′‐ferrocenediylbis(aminocarbene complex) 1 was achieved by its reaction with chloro(methylene)phosphane 2 and triethylamine at ambient temperature, thus yielding the novel diaminophosphane‐bridged [5]ferrocenophane bis(carbene complex) 3. This trimetallic species, which combines the structural features of both ferrocenophane and Fischer carbene complex functional groups, is prone to undergo facile ring opening under mild conditions with formation of bis(2H‐azaphosphirene complexes) 6a,b and 2,3‐dihydro‐1,2,3‐azadiphosphete complex 7. The single‐crystal X‐ray structures of 3 and 7 as well as the reaction courses are discussed.
Light Switches the Ligand! Photochromic Azobenzene–Phosphanes (Eur. J. Inorg. Chem. 14/2010)
Authors: Segarra‐Maset Maria Dolores , van Leeuwen Piet W. N. M. , Freixa Zoraida
Published: May 2010

The cover picture shows the light‐induced isomerization of (E,E,E)‐tris(azobenzene)?phosphane to the (Z,E,E), (Z,Z,E) and (Z,Z,Z) conformers. This photo‐triggered skeletal change has been illustrated by the natural umbrella‐like shape and movements of jellyfish. Details of the synthesis and switchability of this type of ligands and their platinum complexes are discussed in the Short Communication by Z. Freixa et al. on p. 2075 ff.
Diastereoselective Aza‐Baylis–Hillman Reactions: Synthesis of Chiral α‐Allenylamines and 2‐Azetines from Allenic Esters
Authors: Santos Bruna S. , Cardoso Ana L. , Matos Beja Ana , Ramos Silva Manuela , Paixão José A. , Palacios Francisco , Pinho e Melo Teresa M. V. D.
Published: May 2010

The reactivity of allenic esters towards activated N‐sulfonylimines in the presence of DABCO was explored. A formal [2+2] cycloaddition of benzyl buta‐2,3‐dienoate and N‐arylidenebenzenesulfonamides yielded mainly 2‐methyleneazetidines. Interestingly, a DABCO‐catalysed reaction of 2,3‐allenoates, bearing a chiral auxiliary on the ester moiety, with N‐arylidenebenzenesulfonamides led to optically active aza‐Baylis–Hillman products and 2‐azetine derivatives.
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

The [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

The 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

A 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

The 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

Objective

The 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.

Method

Eighty‐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.

Results

Four 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.

Conclusion

Typical 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

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

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

We 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

We 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

In 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

Arctic 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

We 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

Quantitative 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

A 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

The 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

Calnuc 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
Differential ablation of sensory receptors underlies ototoxin‐induced shifts in auditory thresholds of the goldfish (Carassius auratus)
Authors: Ramcharitar John , Selckmann Gordon Michael
Published: May 2010

In recent years, fish models have become popular for investigations of ototoxic agents. However, the vast majority of such studies have focused on anatomical changes in lateral line hair cells after drug adminitration. Using the goldfish (Carassius auratus), we confirm that the acquisition of auditory evoked potentials offers a rapid and non‐invasive method for quantifying ototoxin‐induced changes in hearing sensitivity. Gentamicin (100 mg ml−1) was the drug of choice as it is a well‐studied human ototoxin. Auditory threshold elevation was observed between 300 and 600 Hz and was accompanied by significant reductions in hair cell ciliary bundle densities in specific regions of the utricle and saccule. The correlations between structure and function suggest that differential susceptibility of sensory hair cells to acute gentamicin treatment underlies the frequency‐specific elevation of auditory thresholds. We propose that fish auditory systems should be used alongside the lateral line, for the assessment of ototoxicity in new‐developed drugs. Copyright © 2010 John Wiley & Sons, Ltd.
Oxidative stress biomarkers in Cyprinus carpio exposed to commercial herbicide bispyribac‐sodium
Authors: Toni Cândida , de Menezes Charlene Cavalheiro , Loro Vania Lucia , Clasen Bárbara Estevão , Cattaneo Roberta , Santi Adriana , Pretto Alexandra , Zanella Renato , Leitemperger Jossiele
Published: May 2010

Cyprinus carpio were exposed under field conditions to 20.87 µg l−1 of commercial herbicide bispyribac‐sodium (Nominee®, SC), during 7, 21 and 72 days. Enzymatic parameters such as catalase (CAT), glutathione S‐transferase (GST) and acetylcholinesterase (AChE) activities, as well as thiobarbituric acid‐reactive substances (TBARS) and protein carbonyl contents were studied in different tissues. After 7 days of exposure, GST activity decreased. At the same period, brain AChE activity increased, but a reduction of activity was observed in muscle tissue. Brain TBARS levels increased at 7 days. After 21 days of exposure liver CAT levels and muscle AChE activities decreased. In the same period, liver protein carbonyl and muscle TBARS increased. After 72 days of exposure in the field, AChE activity was reduced in both brain and muscle. Protein carbonyl contents in liver and brain TBARS levels increased. Muscle AChE activity, TBARS and protein carbonyl can be used as biomarkers of exposure to the herbicide bispyribac‐sodium. This study demonstrates effects of exposure to bispyribac‐sodium under rice field conditions on oxidative stress parameters in tissues of Cyprinus carpio. Copyright © 2010 John Wiley & Sons, Ltd.
Femtosecond lentotomy: generating gliding planes inside the crystalline lens to regain accommodation ability
Authors: Lubatschowski Holger , Schumacher Silvia , Fromm Michael , Wegener Alfred , Hoffmann Heike , Oberheide Uwe , Gerten Georg
Published: May 2010

Based on Helmholtz Theory for accommodation the increasing sclerosis of lens nucleus and cortex is the main cause for the developments of presbyopia. Existing therapies, however, do not reverse the stiffness of the crystalline lens and thus do not regain real accommodation ability. A new approach to restore the flexibility of the lens could be realized by photodisruption using ultrafast laser pulses. This process, known as fs‐lentotomy, was used to create micro‐incisions which act as gliding planes inside the crystalline lens without opening the eye globe. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two step resonant Mie scattering correction of infrared micro‐spectral data: human lymph node tissue
Authors: Bird Benjamin , Miljković Miloš , Diem Max
Published: May 2010

In this manuscript, we report the application of EMSC to correct infrared micro‐spectral data recorded from tissue that describe resonant Mie scattering contributions. Small breast micro‐metastases previously undetectable using the raw measured spectra were provided clear contrast from the surrounding tissue after signal correction. The technique also proved transferrable, successfully correcting imaging data sets recorded from multiple patients. It is envisaged more robust methods of supervised analysis can now be constructed to automatically classify and diagnose tissue spectra. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular changes during pollen germination can be monitored by Raman microspectroscopy
Authors: Schulte Franziska , Panne Ulrich , Kneipp Janina
Published: May 2010

The processes associated with pollen germination were studied in vitro for two tree species, Salix caprea and Fraxinus excelsior under different nutrient conditions. The results provide evidence of changes in chemical composition of the pollen grains during germination. From the comparison of spectra of the pollen grain body and the growing pollen tube, it can be concluded that there are major chemical differences between these two morphological units. Comparison of germinated and ungerminated pollen grains reveals alterations in the metabolism. Composition of the germinating pollen grain and its morphological units depends on the plant species, but also on the nutrient conditions. The results suggest species‐specific utilization of metabolite storage, and potential alterations of the pollen outer coat. Furthermore, discharge of molecules into the nutrient medium may depend on the nutrient conditions in the germination experiments. This has implications for further experiments on dynamic processes in pollen and related plant materials. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Super‐resolution imaging and statistical analysis of CdSe/CdS Core/Shell semiconductor nanocrystals
Authors: Kouskousis Betty P. , van Embden Joel , Morrish Dru , Russell Sarah M. , Gu Min
Published: May 2010

Here we present a multifunctional algorithm. Firstly a super‐resolution method is presented for optically imaging the spatial distribution of semiconductor nanocrystals with nanometre localisation. Secondly highly resolved multiple photoluminescence trajectories of hundreds of single semiconductor nanocrystals are obtained simultaneously. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)