bluuebunny/crossref_metadata_2025 huggingface dataset:
Estrogen produced in cultured hippocampal neurons is a functional regulator of a GABAergic machinery
Authors: Ikeda Takamitsu , Matsuki Norio , Yamada Maki K.
Published: October 2006

Accumulating evidence suggests that estrogen is produced locally by the neurons in the brain. We observed that a 48‐hr treatment with the estrogen receptor antagonists ICI 182780 and tamoxifen decreased the level of glutamate decarboxylase (GAD)‐65, a rate‐limiting γ‐aminobutyric acid (GABA)‐synthesizing enzyme, in a dissociated hippocampal neuronal culture. Aromatase is an essential enzyme for estrogen biosynthesis. Treatment with an aromatase inhibitor decreased the GAD 65 level, indicating that estrogen biogenesis functions to maintain the level of this enzyme for GABAergic neurotransmission. Furthermore, insofar as the effect of ICI 182780 was observed equivalently in the presence of either brain‐derived neurotrophic factor (BDNF) or BDNF‐receptor inhibitor K252a, estrogen probably regulates GAD level independently of brain‐derived neurotrophic factor (BDNF). Thus, estrogen produced by neurons is considered to be an intrinsic regulatory factor for neuronal networks that maintain GABAergic neurotransmission. © 2006 Wiley‐Liss, Inc.
Net present value: blame the workman not the tool
Authors: Connor Tom
Published: October 2006

The suggestion that use of the net present value (NPV) rule in major investment decisions induces illusions of certainty and encourages over‐confidence on the part of users is contested. In the event that poor decisions are made when the NPV rule has been used, it is argued here that the causes will be behavioural and competence‐centred rather than technique‐based.

The argument is advanced that the NPV rule is an important rational evaluation technique that provides astute and numerate managers and directors with important economic information and satisfies the demands of the investing community for a wealth creation‐based criterion for strategic decisions.

Copyright © 2006 John Wiley & Sons, Ltd.
The anti‐allergenic properties of milk kefir and soymilk kefir and their beneficial effects on the intestinal microflora
Authors: Liu Je‐Ruei , Wang Sheng‐Yao , Chen Ming‐Ju , Yueh Pei‐Ying , Lin Chin‐Wen
Published: October 2006

Food allergy is now recognized as a worldwide problem, and like other atopic disorders its incidence appears to be increasing. Kefir is reported to possess the ability to reduce intestinal permeation of food antigens; however, no experimental study has clearly evaluated the relationships between kefir consumption, allergen‐specific IgE response, and intestinal microflora. The aim of this study was to evaluate the effect of oral consumption of milk kefir and soymilk kefir on in vivo IgE and IgG1 production induced by ovalbumin (OVA) in mice. The effects of kefir administration on the murine intestinal microflora were also examined. Oral administration of milk kefir and soymilk kefir for 28 days significantly increased the fecal populations of bifidobacteria and lactobacilli, while it significantly decreased those of Clostridium perfringens. Milk kefir and soymilk kefir also significantly decreased the serum OVA‐specific IgE and IgG1 levels for both groups, but not those of the IgG2a analogues. Consumption of milk kefir and soymilk kefir suppressed the IgE and IgG1 responses and altered the intestinal microflora in our supplemented group, suggesting that milk kefir and soymilk kefir may be considered among the more promising food components in terms of preventing food allergy and enhancement of mucosal resistance to gastrointestinal pathogen infection. Copyright © 2006 Society of Chemical Industry
Chemical, biological and sensory evaluation of pasta products supplemented with α‐galactoside‐free lupin flours
Authors: Torres Alexia , Frias Juana , Granito Marisela , Guerra Marisa , Vidal‐Valverde Concepción
Published: October 2006

α‐Galactoside‐free lupin flour has been used to supplement durum wheat semolina flour in order to increase the nutritive value of pasta products. Supplemented pasta products had a shorter cooking time, higher cooking water absorption, cooking loss and protein loss in water than control pasta prepared with only semolina. Sensory evaluation of cooked pastas showed that products supplemented with 80 g kg−1 of α‐galactoside‐free Lupinus angustifolius var. Emir flour or with 100 g kg−1 of α‐galactoside‐free Lupinus angustifolius var. Troll flour showed the same acceptability by panellists as the semolina pasta. These levels of supplementation were selected for further studies. The cooked α‐galactoside‐free lupin/semolina pastas showed higher amounts of protein, dietary fibre, calcium, phosphorus, magnesium, zinc and antioxidant capacity than control pasta and a reasonable level of vitamin B1, vitamin B2 and vitamin E. Biological assessment of cooked pastas indicated that the true protein digestibility did not change after the fortification of semolina but protein efficiency ratio increased sharply in the pasta supplemented with α‐galactoside‐free lupin flours (2.07 and 1.92 for Emir and Troll lupin varieties, respectively) in comparison with the control pasta (1.11). It is concluded that the α‐galactoside‐free lupin flours are an adequate ingredient to improve the nutritional quality of pasta products without adding flatulent oligosaccharides. Copyright © 2006 Society of Chemical Industry
The influence of total mesorectal excision on local recurrence and survival in rectal cancer patients: A population‐based study in greater Amsterdam
Authors: Visser O. , Bakx R. , Zoetmulder F.A.N. , Levering C.C. , Meijer S. , Slors J.F.M. , van Lanschot J.J.B.
Published: October 2006

Background and Objectives

To determine retrospectively in a population‐based setting, the influence of the introduction of total mesorectal excision (TME) on local recurrence and survival in patients with rectal carcinoma.

Methods

All rectal carcinomas diagnosed during 1988–1991 (979 patients, conventional surgery with blunt dissection of the rectum) and 1998–2000 (890 patients, TME resection) were selected from the Amsterdam Cancer Registry. For all patients who underwent a macroscopically radical resection in the absence of distant dissemination, information on the occurrence of local recurrent disease and distant metastasis was collected.

Results

The cumulative 5‐year recurrence rate decreased significantly from 20% for patients diagnosed in 1988–1991 to 11% in 1998–2000. Stage (T‐category, nodal status), period of diagnosis (conventional surgery vs. TME resection), radiotherapy, and chemotherapy were independent variables of local recurrence in multivariate analysis. There was a non‐significant trend for improved 5‐year relative survival for all rectal carcinoma cases from 52% (95% CI 48–55) for patients diagnosed in 1988–1991 to 59% (95% CI 55–63) in 1998–2000.

Conclusions

A significant decrease in local recurrence and a trend for improved relative survival were observed. The broad introduction of TME and the shift towards preoperative radiotherapy are the most plausible explanations for these observations. J. Surg. Oncol. 2007; 95: 447–454. © 2006 Wiley‐Liss, Inc.
Segmenting mainland Chinese residents based on experience, intention and desire to visit Hong Kong
Authors: Hsu Cathy , Crotts John C.
Published: October 2006

The general consensus among marketers is that the People's Republic of China will have an enormous impact on the world's economy. However, much of this discussion is centred on China's strength as a centre of manufacturing and exports. The increase in affluence in pockets of China's 1.3 billion residents has also been the focus of firms interested in this large and virtually untapped consumer market. However, relatively little attention has been given to this market as potential sources of tourists. The purpose of this study was to profile the important visitor segments from mainland China who had previously visited, had the intention to visit or desired to visit Hong Kong—a destination traditionally priced and positioned for Western markets. Based on a sample of 470 Chinese from three cities in the mainland, the distinctive characteristics of tourists who had previously visited Hong Kong and who had strong intentions or interest to visit in the future were identified. It is hoped that this information will help tourism marketing professionals not only gain insights as to the potential of China as a source of visitors, but also highlight a useful approach to the market segmentation process. Copyright © 2006 John Wiley & Sons, Ltd.
Swimming with dolphins: a phenomenological exploration of tourist recollections
Authors: Curtin Susanna
Published: October 2006

Opportunities to swim with dolphins both in captivity and in the wild have recently proliferated. In order to understand the nature of the swim‐with‐dolphin experience, 14 respondents were selected to take part in a phenomenological study based on their recollections of the activity. The results discuss the physical attributes of the experience, the attraction of dolphins, the importance of making a connection either through eye contact or touch, prior conceptions of what it would be like and, finally, ‘animal sensitivities’ towards the nature of the performance. Cognitive dissonance and a heavily anthropomorphic virtual capital are present in nearly all respondents. Copyright © 2006 John Wiley & Sons, Ltd.
The design of single particle laser mass spectrometers
Authors: Murphy Daniel M.
Published: October 2006

This review explores some of the design choices made with single particle mass spectrometers. Different instruments have used various configurations of inlets, particle sizing techniques, ionization lasers, mass spectrometers, and other components. Systematic bias against non‐spherical particles probably exceeds a factor of 2 for all instruments. An ionization laser tradeoff is the relatively poor beam quality and reliability of an excimer laser versus the longer wavelengths and slower response time of an Nd‐YAG laser. Single particle instruments can make special demands on the speed and dynamic range of the mass spectrometers. This review explains some of the choices made for instruments that were developed for different types of measurements in the atmosphere. Some practical design notes are also given from the author's experience with each section of the instrument. Published 2006 Wiley Periodicals, Inc., Mass Spec Rev 26:150–165, 2007
Wilson's disease tremor is associated with magnetic resonance imaging lesions in basal ganglia structures
Authors: Südmeyer Martin , Saleh Andreas , Wojtecki Lars , Cohnen Mathias , Gross Joachim , Ploner Markus , Hefter Harald , Timmermann Lars , Schnitzler Alfons
Published: October 2006

Wilson's disease (WD) is an inherited disorder of copper metabolism yielding marked motor deficits, including a severely disabling tremor. As a structural correlate of the disease, a variety of cerebral abnormalities has been revealed. However, the relationship between motor deficits and cerebral lesions has remained largely unknown. Here, we investigated correlation between WD tremor and cerebral magnetic resonance imaging (MRI) findings. Cerebral MRI abnormalities in 6 symptomatic WD patients were compared to findings in 6 asymptomatic WD patients and 10 healthy controls. All patients were treated with long‐term copper chelating therapy. Motor symptoms including tremor were determined by Unified Parkinson's Disease Rating Scale Part III (UPDRS‐III). MRI findings in symptomatic WD patients revealed significant symmetric T2*‐weighted hypointense signal alterations of globus pallidus, head of the caudate nucleus, and substantia nigra. In contrast, MRI of asymptomatic WD patients did not differ from healthy controls. Correlation analysis revealed a significant positive correlation between MRI basal ganglia lesions and UPDRS action tremor score. Our results demonstrate for the first time that Wilson's disease tremor is associated with lesions of the globus pallidus, the head of the caudate nucleus, and the substantia nigra. © 2006 Movement Disorder Society
Finite dimensional approximations for the electronic ground state solution of a molecular system
Authors: Zhou Aihui
Published: October 2006

In this paper, finite dimensional approximations for the electronic ground state solution of a molecular system are studied in the Thomas–Fermi–von Weizsäcker type setting. The convergence of the finite dimensional approximations obtained by a Galerkin discretization of the nonlinear eigenvalue equation is proved. In particular, several upper bounds of the approximation errors are established. Copyright © 2006 John Wiley & Sons, Ltd.
Role of sialic acid in bovine sperm–zona pellucida binding
Authors: Velásquez José Guillermo , Canovas Sebastián , Barajas Patricia , Marcos Julián , Jiménez‐Movilla María , Gallego Ricardo Gutiérrez , Ballesta José , Avilés Manuel , Coy Pilar
Published: October 2006

Sperm binding activity has been detected in zona pellucida (ZP) glycoproteins and it is generally accepted that this activity resides in the carbohydrate moieties. In the present study we aim to identify some of the specific carbohydrate molecules involved in the bovine sperm–ZP interaction. We performed sperm binding competition assays, in vitro fecundation (IVF) in combination with different lectins, antibodies and neuraminidase digestion, and chemical and cytochemical analysis of the bovine ZP. Both MAA lectin recognising α‐2,3‐linked sialic acid and neuraminidase from Salmonella typhimurium with catalytic activity for α‐2,3‐linked sialic acid, demonstrated a high inhibitory effect on the sperm–ZP binding and oocyte penetration. These results suggest that bovine sperm–ZP binding is mediated by α‐2,3‐linked sialic acid. Experiments with trisaccharides (sialyllactose, 3′‐sialyllactosamine and 6′‐sialyllactosamine) and glycoproteins (fetuin and asialofetuin) corroborated this and suggest that at least the sequence Neu5Ac(α2‐3)Gal(β1‐4)GlcNAc is involved in the sperm–ZP interaction. Moreover, these results indicate the presence of a sperm plasma membrane specific protein for the sialic acid. Chemical analysis revealed that bovine ZP glycoproteins contain mainly Neu5Ac (84.5%) and Neu5GC (15.5%). These two types of sialic acid residues are probably linked to Galβ1,4GlcNAc and GalNAc by α‐2,3‐ and α‐2,6‐linkages, respectively, as demonstrated by lectin cytochemical analysis. The use of a neuraminidase inhibitor resulted in an increased number of spermatozoa bound to the ZP and penetrating the oocyte. From this last result we hypothesize that a neuraminidase from cortical granules would probably participate in the block to polyspermy by removing sialic acid from the ZP. Mol. Reprod. Dev. 74: 617–628, 2007. © 2006 Wiley‐Liss, Inc.
A simplified mesh‐free method for shear bands with cohesive surfaces
Authors: Rabczuk T. , Areias P. M. A. , Belytschko T.
Published: October 2006

A simple methodology to model shear bands as strong displacement discontinuities in a mesh‐free particle method is presented. The shear band is represented as a set of sheared particles. A sheared particle is developed through enrichment by tangential displacement discontinuities. The representation of the shear band as set of cohesive segments provides a simple and versatile model of shear bands. The loss of material stability is used as the criterion for switching from a classical continuum description of the constitutive behaviour to a traction‐separation law acting on the discontinuity surface. The method is implemented for two and three dimensions. Examples of shear band progression in rate‐dependent and rate‐independent materials are presented, including the Kalthoff problem, where the transition from brittle fracture to shear banding is studied. Copyright © 2006 John Wiley & Sons, Ltd.
Probabilistic safety analysis of structures under hybrid uncertainty
Authors: Chakraborty Subrata , Sam Palash Chandra
Published: October 2006

The probabilistic and the possibilistic methods of safety evaluation of structure under uncertain parameters have been developed independently. When the structural system is defined with some of the input parameters as possibilistic and others are sufficient enough to model as probabilistic, available literatures normally start with either probabilistic or possibilistic description of all the variables. This may pose restriction on necessary flexibility to the designer at early stage of modelling of the structural system. The primary objective of the present work is to critically examine various emerging methods of transformation of the possibilistic variables to equivalent probabilistic variables so that probabilistic safety evaluation approach becomes compatible with the nature and quality of the input data. Relying on the fundamental concept of equivalent transformations, i.e. the entropy based transformation and the scaling of fuzzy membership function, the reliability analysis is proposed in the framework of second moment format. In doing so, the bounds on the reliability indices based on the evidence theory are also obtained encompassing the first‐order reliability analysis for consistent comparison among alternative transformations. Finally, the reliability computation under hybrid uncertainty is elucidated numerically with examples for comparative study on the suitability of the transformation alternatives. Copyright © 2006 John Wiley & Sons, Ltd.
A phonon heat bath approach for the atomistic and multiscale simulation of solids
Authors: Karpov E. G. , Park H. S. , Liu Wing Kam
Published: October 2006

We present a novel approach to numerical modelling of the crystalline solid as a heat bath. The approach allows bringing together a small and a large crystalline domain, and model accurately the resultant interface, using harmonic assumptions for the larger domain, which is excluded from the explicit model and viewed only as a hypothetic heat bath. Such an interface is non‐reflective for the elastic waves, as well as providing thermostatting conditions for the small domain. The small domain can be modelled with a standard molecular dynamics approach, and its interior may accommodate arbitrary non‐linearities. The formulation involves a normal decomposition for the random thermal motion term R(t) in the generalized Langevin equation for solid–solid interfaces. Heat bath temperature serves as a parameter for the distribution of the normal mode amplitudes found from the Gibbs canonical distribution for the phonon gas. Spectral properties of the normal modes (polarization vectors and normal frequencies) are derived from the interatomic potential. Approach results in a physically motivated random force term R(t) derived consistently to represent the correlated thermal motion of lattice atoms. We describe the method in detail, and demonstrate applications to one‐ and two‐dimensional lattice structures. Copyright © 2006 John Wiley & Sons, Ltd.
Optimal design of skeletal structures using ant colony optimization
Authors: Kaveh A. , Shojaee S.
Published: October 2006

In this article, the ant colony optimization (ACO) algorithm is employed for optimal design of skeletal structures. The advantage of using ACO lies in the fact that the discrete spaces can be optimized in a simple manner. The results of the present method are compared to those of the other optimization algorithms for some classic examples from the literature. Copyright © 2006 John Wiley & Sons, Ltd.
Proteomic knowledge of human aquaporins
Authors: Magni Fulvio , Sarto Cecilia , Ticozzi Davide , Soldi Monica , Bosso Niccolò , Mocarelli Paolo , Kienle Marzia Galli
Published: October 2006

Aquaporins (AQPs) are an ubiquitous family of proteins characterized by sequence similarity and the presence of two NPA (Asp‐Pro‐Ala) motifs. At present, 13 human AQPs are known and they are divided into two subgroups according to their ability to transport only water molecules (AQP0, AQP1, AQP2, AQP4, AQP5, AQP6, and AQP8), or also glycerol and other small solutes (AQP3, AQP7, AQP9, AQP10, AQP12). The genomic, structural, and functional aspects of this family are briefly described. In particular, proteomic approaches to identify and characterize the most studied AQPs, mainly through SDS‐PAGE followed by MS analysis, are discussed. Moreover, the clinical importance of the best studied aquaporin (AQP1) in human diseases is also provided.
Apoptosis induction and growth suppression by U19/Eaf2 is mediated through its ELL‐binding domain
Authors: Hahn Junghyun , Xiao Wuhan , Jiang Feng , Simone Federico , Thirman Michael J. , Wang Zhou
Published: October 2006

BACKGROUND

U19/Eaf2 is an androgen‐response gene and its downregulation is frequently observed in advanced human prostate cancer. U19/Eaf2 interacts with ELL, a fusion partner of MLL in the (11;19) (q23;p13.1) translocation in acute myeloid leukemia. U19/Eaf2 overexpression induces apoptosis and suppresses xenograft tumor growth.

METHODS

Transfection and colony formation were used to assay for apoptosis and growth suppression of various U19/Eaf2 mutants. Co‐immunoprecipitation was performed to test the interaction between the U19/Eaf2 constructs and ELL.

RESULTS

The region of U19/Eaf2 essential for apoptosis and growth suppression was mapped to amino acids 68–113. This region was necessary and sufficient for binding ELL. Co‐expression of U19/Eaf2 and ELL in 293 cells lead to significant increase in cell death and growth suppression.

CONCLUSIONS

These observations argue that the interaction with ELL is essential for the induction of apoptosis and growth suppression by U19/Eaf2. Prostate © 2006 Wiley‐Liss, Inc.
Angiotensin II type 1 receptor antagonist as an angiogenic inhibitor in prostate cancer
Authors: Kosaka Takeo , Miyajima Akira , Takayama Eiji , Kikuchi Eiji , Nakashima Jun , Ohigashi Takashi , Asano Tomohiko , Sakamoto Michiie , Okita Hajime , Murai Masaru , Hayakawa Masamichi
Published: October 2006

BACKGROUND

Angiotensin II (AII) type 1 receptor (AT1R) antagonists are used widely as antihypertensive agents, and long‐term AT1R blockade may have a protective effect against cancer. We previously demonstrated that specific AT1R blockade with candesartan, an AT1R antagonist, inhibited vascular endothelial growth factor (VEGF) production and dramatically decreased lung metastasis of renal cancer by inhibiting tumor angiogenesis. This study was then undertaken to investigate the effects of AT1R blockade using candesartan in prostate cancer (PCa).

METHODS

We first determined whether hormone‐independence is associated with tumor angiogenesis and AT1R expression. Accordingly, we postulated that AT1R blockade may affect angiogenesis in androgen‐independent PCa rather than in androgen‐dependent PCa, and investigated the effects of AII and candesartan on PCa cell lines and a tumor xenograft model.

RESULTS

A human hormone‐refractory PCa (HRPC) and C4‐2 androgen‐independent PCa cell line showed significantly higher expression of VEGF, MVD, and AT1R than did human androgen‐dependent PCa and an LNCaP androgen‐dependent PCa cell line. In vitro, AII and candesartan did not directly affect the proliferation of LNCaP and C4‐2 cells, but candesartan significantly suppressed VEGF production in C4‐2 cells. In vivo, candesartan significantly suppressed VEGF expression, serum PSA concentration and tumor growth (1.1 ± 0.2, 45.0 ± 17.6 ng/ml, 235.8 ± 37.4 mm3) in C4‐2 xenografts in castrated mice, compared with the controls (2.4 ± 0.6, 376.7 ± 74.2 ng/ml, 830.8 ± 147.6 mm3).

CONCLUSIONS

Candesartan exerted preventive effects on HRPC, rather than on androgen‐sensitive PCa, through the inhibition of tumor angiogenesis. Prostate 67:41–49, 2007. © 2006 Wiley‐Liss, Inc.
Elevated levels of the mismatch repair protein PMS2 are associated with prostate cancer
Authors: Norris Alixanna M. , Woodruff R.D. , D'Agostino Ralph B. , Clodfelter Jill E. , Scarpinato Karin Drotschmann
Published: October 2006

Background

Defects in mismatch repair (MMR) proteins have been identified in various types of cancer. However, an association with prostate cancer has been controversial. Defective MMR results in genome instability with detrimental consequences that significantly contribute to tumorigenesis. This study determined alterations in key MMR protein levels in prostate cancer with the goal to identify prognostic markers.

Methods

Prostatectomy samples were immunohistochemically stained and the relative presence or absence of key proteins MSH2, MLH1, and PMS2 determined. Cancer tissue of distinct grades was compared with the normal surrounding tissue. Microsatellite instability (MSI) in altered tissues was determined according to NCI guidelines.

Results

In contrast to reports that associate a lack of individual MMR proteins with tumorigenesis, a significant increase in PMS2 levels was identified in PIN lesions and prostate cancer tissue. This elevation in PMS2 was independent of changes in levels in its heterodimeric partner, MLH1. Prostate tumors with elevated levels of PMS2 were genetically unstable, which was corrected by MLH1 co‐elevation.

Conclusions

This is the first documentation of detrimental consequences associated with the increase in a MMR protein in human cancer. This study recognizes PMS2 elevation as a prognostic marker in pre‐neoplastic and prostate cancer lesions. This result has significant implications for future diagnostic and treatment measures. Prostate © 2006 Wiley‐Liss, Inc.
Insights into protein structure and function from disorder–complexity space
Authors: Weathers Edward A. , Paulaitis Michael E. , Woolf Thomas B. , Hoh Jan H.
Published: October 2006

Intrinsically disordered proteins have a wide variety of important functional roles. However, the relationship between sequence and function in these proteins is significantly different than that for well‐folded proteins. In a previous work, we showed that the propensity to be disordered can be recognized based on sequence composition alone. Here that analysis is furthered by examining the relationship of disorder propensity to sequence complexity, where the metrics for these two properties depend only on composition. The distributions of 40 amino acid peptides from both ordered and disordered proteins are graphed in this disorder–complexity space. An analysis of Swiss‐Prot shows that most peptides have high complexity and relatively low disorder. However, there are also an appreciable number of low complexity–high disorder peptides in the database. In contrast, there are no low complexity–low disorder peptides. A similar analysis for peptides in the PDB reveals a much narrower distribution, with few peptides of low complexity and high disorder. In this case, the bounds of the disorder–complexity distribution are well defined and might be used to evaluate the likelihood that a peptide can be crystallized with current methods. The disorder–complexity distributions of individual proteins and sets of proteins grouped by function are also examined. Among individual proteins, there is an enormous variety of distributions that in some cases can be rationalized with regard to function. Groups of functionally related proteins are found to have distributions that are similar within each group but show notable differences between groups. Finally, a pattern matching algorithm is used to search for proteins with particular disorder–complexity distributions. The results suggest that this approach might be used to identify relationships between otherwise dissimilar proteins. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Thermoluminescence response and apparent anomalous fading factor of Durango fluorapatite as a function of the heating rate
Authors: Kitis G. , Polymeris G. S. , Pagonis V. , Tsirliganis N. C.
Published: October 2006

The anomalous fading (AF) of the Thermoluminescence (TL) signal has been observed in Durango apatite, and is believed to be caused by electrons transferred to the recombination sites via a tunnelling effect. The AF factor is a property unique for each glow‐peak of a glow‐curve and shows a remarkable stability, even when extreme experimental conditions are applied to this material. In the present work the AF is studied as a function of the rate at which the material is heated in order to obtain its TL. In this experimental study it is found that the TL response of Durango apatite is drastically increased as the rate of heating increases, contrary to what is expected from standard kinetic models of TL. An important consequence of this result is that, since the AF rate is monitored through the TL signal, the variations of TL as a function of the heating rate will be passed on to the evaluation of the AF rate. The result is an apparent decrease of the AF with an increasing heating rate, although the actual AF effect has no relation with the TL readout process. A possible explanation is proposed for the increase of the TL response and for the apparent decrease of the AF rate with the rate of heating. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rapid online equilibration method to determine the D/H ratios of non‐exchangeable hydrogen in cellulose
Authors: Filot Marc S. , Leuenberger Markus , Pazdur Anna , Boettger Tatjana
Published: October 2006

An improved method for the determination of deuterium‐to‐hydrogen (D/H) ratios of non‐exchangeable hydrogen in cellulose is presented. The method is based on the equilibration reaction of the hydroxyl hydrogen of cellulose and water vapour of known isotopic composition. The equilibrated cellulose is pyrolysed and the total D/H ratio determined by subsequent online isotope ratio mass spectrometry (IRMS). With a mass balance system the D/H ratio of non‐exchangeable hydrogen is recalculated after an empirical calibration has been performed, yielding a mean exchangeability of 0.239 and an equilibrium fractionation factor of 1.082 between the hydroxyl hydrogen of cellulose and water hydrogen at 110°C. Equilibration takes 10 min per sample. Results obtained by this online equilibration method agree very well with values obtained by the nitration technique (R2 = 0.941). The uncertainty of the equilibration method is ±4‰ resulting from a single standard deviation of ±2.8‰ for the equilibration determined by standard cellulose and 2.8‰ from the variable exchangeability of the hydroxyl hydrogen in cellulose due to crystalline areas. The latter uncertainty may be lowered by minimising the crystallinity of the cellulose. Advantages of this new technique are (i) the considerably reduced sample amount required (as low as 0.2 mg, ideally 0.5 mg compared with 20 mg for the conventional nitration technique); (ii) an approximately 100‐fold reduced process time; and (iii) no need for the hazardous chemicals used in the nitration technique. Copyright © 2006 John Wiley & Sons, Ltd.
High‐precision isotopic analysis of palmitoylcarnitine by liquid chromatography/electrospray ionization ion‐trap tandem mass spectrometry
Authors: Guo ZengKui , Yarasheski Kevin , Jensen Michael D.
Published: October 2006

Single quadrupole gas chromatography/mass spectrometry (GC/MS) has been widely used for isotopic analysis in metabolic investigations using stable isotopes as tracers. However, its inherent shortcomings prohibit it from broader use, including low isotopic precision and the need for chemical derivatization of the analyte. In order to improve isotopic detection power, liquid chromatography/electrospray ionization ion‐trap tandem mass spectrometry (LC/ESI‐itMS2) has been evaluated for its isotopic precision and chemical sensitivity for the analysis of [13C]palmitoylcarnitine. Over the enrichment range of 0.4–10 MPE (molar % excess), the isotopic response of LC/ESI‐itMS2 to [13C]palmitoylcarnitine was linear (r = 1.00) and the average isotopic precision (standard deviation, SD) was 0.11 MPE with an average coefficient of variation (CV) of 5.6%. At the lower end of isotopic enrichments (0.4–0.9 MPE), the isotopic precision was 0.05 MPE (CV = 8%). Routine analysis of rat skeletal muscle [13C4]palmitoylcarnitine demonstrated an isotopic precision of 0.03 MPE for gastrocnemius (n = 16) and of 0.02 MPE for tibialis anterior (n = 16). The high precision enabled the detection of a small (0.08 MPE) but significant (P = 0.01) difference in [13C4]palmitoylcarnitine enrichments between the two muscles, 0.51 MPE (CV = 5.8%) and 0.43 MPE (CV = 4.6%), respectively. Therefore, the system demonstrated an isotopic lower detection limit (LDL) of ≤0.1 MPE (2 × SD) that has been impossible previously with other organic mass spectrometry instruments. LC/ESI‐itMS2 systems have the potential to advance metabolic investigations using stable isotopes to a new level by significantly increasing the isotopic solving power. Copyright © 2006 John Wiley & Sons, Ltd.
Prophage Mu induction as a tool to analyze mobile genetic element responses to external agents
Authors: Dubow Michael S. , Shinder Gayle
Published: October 2006

Mobile genetic elements have been found in the genomes of both procaryotic and eucaryotic organisms. Their unique capacity to move (or transpose) to new chromosomal locations has been critical to their persistence and their ability to affect gene structure and expression. It is conceivable that many physical and chemical agents may induce non‐specific DNA transpositions which can result in genomic rearrangements and mutations. We have derived a simple procedure to detect the induction of DNA transposition using bacteriophage Mu, a temperate coliphage whose 37 kilobase linear double‐stranded DNA genome behaves as a transposable element during lytic growth and lysogeny. Our assay measures the ability of a chemical to enhance or inhibit the induction of Mu DNA transposition and lytic growth. We have examined a wide variety of mutagens, carcinogens and common chemical compounds and found that most of these agents had little effect on prophage Mu induction and lytic growth at all doses tested. However, many DNA‐damaging agents showed a dose‐dependent decrease in both the number of plaque‐forming units and the number of colony‐forming units. We did find that the frequency of prophage Mu induction can be stimulated by certain amino acid analogues, notably azetidine 2‐carboxylic acid, but not by others. These results indicate that the response of mobile genetic elements to external agents is not a simple one, and may reflect the necessary presence of an element and cellular regulatory pathway to control these endogenous mutators.
“Basic” respiration rate as a tool for prediction of pesticide persistence in soil
Authors: Torstensson Lennart , Stenström John
Published: October 2006

A method for determination of the “basic” respiration rate of soils, as the rate of O2‐consumption, has been developed. It includes standardization of both the handling of samples before determination and of the temperature and the water content at which the determination is performed. The respiration rate determined in this way varies less than normally occurs when samples of a soil are taken over a period of time. Neither the handling at sampling nor the variation in time before determination influences the result. Comparisons between a soil's respiration rate and its ability to decompose a pesticide are more easily made if the decomposition data can be expressed in mathematical form and thereby linearized. This has been done for linuron and glyphosate by plotting the decomposition data according to the formulac=co–k√tt.Good correlation between the rate of respiration and the rate of decomposition (k‐value) was found for linuron and glyphosate in laboratory experiments and also for glyphosate in field experiments.
Toxicity analysis of leachates from hazardous wastes via microtox and daphnia magna
Authors: Calleja A. , Baldasano J. M. , Mulet A.
Published: October 2006

One of the most common ways of surface and ground water contamination from hazardous wastes is through its leachates. Toxicity is a meaningful parameter allowing an integrated evaluation of the potential danger of leachates. Two bioassays were considered for measuring toxicity: Microtox and Daphnia magna. The toxicity was measured on leachates obtained, using different leaching procedures, from wastes of a pesticide manufacturing industry and sludge from electroplating wastewater. Twenty‐two tests were carried out, measuring IC50 for D. magna and EC50 for Microtox. Both bioassays were compared using three toxicity criteria. The first criterium is classification on toxic/non‐toxic at 25 and 50% leachate concentration. The second criterium is classification on percent ranks, and the third on log ranks. Considering these criteria, the agreement between both bioassays is within a 75–85%. It is shown that both, Microtox and D. magna assays could be used as toxicity indicators for the wastes considered. The sensitivity of the bioassays is different depending on leachate composition. In all samples, the leachate concentration of chemicals was measured.
A simple microplate algal assay technique for aquatic toxicity assessment
Authors: Blaise C. , Legault R. , Bermingham N. , Van Coillie R. , Vasseur P.
Published: October 2006

A simple, miniaturized algal assay procedure using microplates has been developed to assess aquatic toxicity with the green alga, Selenastrum capricornutum. Cell count‐generated EC50 data comparisons with the classic assay using flasks have indicated good agreement between the two methods following toxic assessment of various wastewater samples and metal solutions. Parametric comparisons (ATP us cell counts) with the microplate method show equally good correlation. The technique is highly versatile in conducting basic algal bioassays for varying times (4‐hour, 4‐day, 8‐day EC50's) and with differing parameters, depending on set objectives. Other interesting features of the microplate technique include handling rapidity, economy, space‐saving convenience, and automation potential.
Environmental effects testing with quantitative microbial analysis: Chemical signatures correlated within situbiofilm analysis by FT/IR
Authors: White David C.
Published: October 2006

Chemical measures for the biomass, community structure, nutritional status, and metabolic activities of the microbiota have shown a remarkable responsiveness to changes in the bulk fluid physical and chemical properties, the chemistry, biodegradability, and microtopology of the surfaces, as well as biological factors such as predation. Chemical analysis of the microbiota (bacteria, algae, fungi, protozoa, and micrometazoa with their extracellular products <0.5mm in diameter) does not require quantitative release of the organisms from surfaces or that the organisms are able to form colonies in subcultures. The sensitivity of the microbiota to changes in their habitat suggests that these chemical measures could provide a quantitative method for environmental effects testing. Changes in the marine benthic microbiota exposure to xenobiotics at the ug/l level or oil and gas well‐drilling fluids demonstrate this sensitivity. These analyses do not destroy the vital interactions within microcolonies of mixed physiological types that characterize many environments. The chemical measures are destructive. Non‐destructive analysis of biofilms of areas in the size range of microcolonies by Fourier transforming infrared spectrometry may ultimately provide the most effective method for environmental effects testing.
The effect of selected biocides on sulfate‐reducing bacteria
Authors: L‐zanfaly H. T. E , Kassim E. A. , Hassan H. M.
Published: October 2006

Growth of 26 strains of sulfate‐reducing bacteria isolated from the environment was inhibited by two cationic surfactants, namely, Hyamine 2389 and Lutensit K‐LC at concentrations of 166 mg/1 or less. Hyamine 1622 (cationic) inhibited 21 strains at a concentration of 100 mg/1. Two strains were resistant to 100 mg/1 of Chloramine T, but 4 strains were resistant to 60 mg/1. Hydrogen peroxide at the concentration of 583 mg/1 was able to prevent the growth of 17 strains.

Time‐kill tests indicated that the majority of the strains were sensitive to all tested biocides during the first few minutes of exposure which extended to about one hour at lower concentrations.

Lowering the temperature during exposure of bacteria did not exert any substantial effect on the biocidal efficiency of the tested chemicals. Higher concentrations of the biocides may require the lowering or raising of the pH and in the presence of organic matter.
Evaluation of toxicity test procedure for screening treatability potential of waste in soil
Authors: Matthews J. E. , Hastings L.
Published: October 2006

A toxicity procedure has been developed and proposed for use in establishing acceptable initial loading rates and detoxification potentials for hazardous industrial waste when combined with soil. The procedure involves conducting toxicity screening and toxicity reduction experiments using selected waste‐soil combinations. These experiments employ a bacterial bioluminescence assay (MicrotoxTM) to determine acute toxicity of organic contaminants contained in the water soluble fraction (WSF) of waste‐soil mixtures. Toxicity screening test results are used to establish a range of loading rates acceptable for use in subsequent waste‐soil treatability studies. Toxicity reduction experimental results are used to determine soil detoxification potentials over time for soluble toxic organics contained in the waste‐soil loading combination selected. A major factor in determining acceptability of any test procedure is whether or not different investigators can achieve reproducible and comparable results. This paper describes the proposed procedure and reports results from toxicity experiments conducted concurrently by two laboratories using aliquots from the same soil and waste samples. Comparability of results was reported to be a function of the similarity of waste sample aliquots used in the toxicity experiments. Toxicity screening results for uniform technical grade creosote aliquots were highly comparable between the two laboratories, while results for highly variable creosote wood preserving waste (WPC) aliquots were much less comparable. Toxicity reduction experimental results for the WPC waste also indicated significant variation between laboratories for initial (Day 0) samples; however, the same patterns of detoxification over time were observed by each laboratory with toxicity results at the end of the experimental period (Day 42) being similar. Although the research described in this article has been funded wholly or in part by the U.S. Environmental Protection Agency, it has not been subjected to the agency's peer and administrative review and therefore may not necessarily reflect the views of the agency and no official endorsement should be inferred.
The action of pesticides on microorganisms. I. parathion
Authors: Rosas Susana B. , De Storani Maria M. Carranza
Published: October 2006

Previous experiments indicate that parathion, DDT, aldrin, and dieldrin induce changes in fatty acid and phospholipid composition in Escherichia coli. The effect of parathion on the growth and viability of E. coli, P. aeruginosa and R. meliloti was studied. When the pesticide was present at a concentration of 8.6 × 10−6M, the following effects were observed: P. aeruginosa growth was not affected, E. coli was slightly inhibited and R. meliloti was affected adversely in the incubation mixture. We also examined the effects on the cell membrane components such as phospholipids and proteins; both quantitative and qualitative changes were observed. The results varied according to the microorganism utilized. Our data revealed alterations in the phospholipids that may be an important adaptative response of microorganism to growth in the presence of the pesticides.
The development of whole cell biosensors for on‐line screening of herbicide pollution of surface waters
Authors: Rawson David M. , Willmer Allison J. , Cardosi Marco F.
Published: October 2006

The use of mediator assisted amperometric whole‐cell biosensors, monitoring microbial photosynthetic electron transfer, to screen for herbicides in intake protection by the water industry is described. Cells harvested from axenic cultures are loaded onto bacteriological filters and held against a working carbon electrode polarised against the silver chloride reference. Redox mediators are reduced by the microorganisms and then reoxidised at the working electrode resulting in a flow of current. For on‐line applications the sensors are controlled by a programmable electrochemical analyser (Artek) and housed in specially designed perspex flow cells which incorporate light emitting diodes (LEDs) for photosynthetic stimulation. A range of cyanobacteria and algae have been tested, but biosensors incorporating unicellular cyanobacteria have proven the most successful. Results obtained using the cyanobacterium Synechococcus show detection levels of less than 200 ppb with response times of less than ten minutes for selected herbicides. Sensor stability in the absence of pollutant poisoning has been found to be greatly influenced by the choice of mediator. Membrane penetrating mediators such as ‐benzoquinone reduce sensor life to about 24 hours, while a sensor life of up to six days has been achieved with ferricyanide.
Toxicity and accumulation of cadmium with respect to algae and cyanobacteria: A review
Authors: Vymazal Jan
Published: October 2006

Cadmium is always found in association with zinc. However, zinc is an essential micronutrient in living cells, whereas cadmium has no known useful biological function. In fact, cadmium is ranked among the most hazardous trace elements in the environment and is highly toxic to all components of aquatic communities. Cadmium in soils seems tightly held and is not readily removed by leaching, and consequently, cadmium in freshwaters is mostly connected with human activities. The concentration of Cd in natural waters is usually less than 1 μg. L−1 but the values vary greatly among localities; the highest concentrations of cadmium have been observed in areas with acid mine drainage. The important mechanism of toxic action of Cd on algae and cyanobacteria is thought to be the „poisoning”︁ of enzymes, but many other toxic actions are known. A variety of environmental factors are known to modify the toxicity of cadmium. It is very difficult to allow for all of these factors simultaneously to predict the effect that a given amount of a metal will have on a given algal population. Uptake of Cd and other heavy metals to produce an internal concentration than in the external environment appears widespread in algae and cyanobacteria.
Assessment of methods for evaluating the treatability of sewage and the effects of industrial discharges
Authors: Robinsons R. J.
Published: October 2006

Five tests, based on methods currently in use for measuring the inhibition of rates of respiration, nitrification, and growth of bacteria, are evaluated for use as screening tests for assessing the treatability of settled sewage and toxicity of industrial effluent. A treatability factor is derived for each test for a series of settled sewages and a toxicity factor for industrial effluents by comparison with control standards. The Microtox test gives greater sensitivity, repeatability, and precision, but possible problems in the interpretation of the results warrant further comparison with the remaining tests, all of which show reasonable promise.
Thymidine incorporation and bacterial mortality as ecotoxicological assessment in aquatic habitats
Authors: Martínez J. , Vives‐Rego J.
Published: October 2006

The impact of urban and industrial wastes on marine bacteria was assessed by thymidine incorporation and bacterial mortality. The results indicate that heavy metals are highly toxic to the marine bacteria, while alkyl benzene sulfonate exhibits a moderate biotoxicity. The lyophilized wastes are, however, only mildly toxic to the marine bacteria. In general, the bacterial mortality rate is increased with the industrial waste loading.