bluuebunny/crossref_metadata_2025 huggingface dataset:
From atomic and molecular orbitals to chemical orbitals
Authors: Clementi Enrico , Corongiu Giorgina
Published: February 2008

In this work, we analyze the molecular orbitals (MO) one‐electron functions of the Hartree‐Fock (HF) model and the atomic orbitals (AO) of the Heitler‐London (HL) and valence bond (VB) models. The complementarity of MO with AO orbitals has been evidenced with the recent Hartree‐Fock‐Heitler‐London model. We propose a new and general one‐electron function, the chemical orbital (CO) and the corresponding determinantal wave function, the chemical orbital wave function, ΨCO. We show that the ΨCO can be decomposed into a specific HF‐HL function with ionic components, designated “adjoined HF‐HL function” and that the HF‐HL, HF, and VB wave functions can be derived from the ΨCO wave function. A single “adjoined HF‐HL function” can realistically represent molecular systems from the united atom, to equilibrium distances, to dissociation; short linear expansions of “adjoined HF‐HL functions” yield accurate nonrelativistic energies. Preliminary test computations with “adjoined HF‐HL functions” are presented for the ground state of the H2 and LiH molecules © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Cooperative use of unmanned sea surface and micro aerial vehicles at Hurricane Wilma
Authors: Murphy Robin R. , Steimle Eric , Griffin Chandler , Cullins Charlie , Hall Mike , Pratt Kevin
Published: February 2008

On Oct. 24, 2005, Hurricane Wilma, a category 5 storm, made landfall at Cape Romano, Florida. Three days later, the Center for Robot‐Assisted Search and Rescue at the University of South Florida deployed an iSENYS helicopter and a prototype unmanned water surface vehicle, AEOS‐1, to survey damage in parts of Marco Island, 14 km from landfall. The effort was the first known use of unmanned sea surface vehicles (USVs) for emergency response and established their suitability for the recovery phase of disaster management by detecting damage to seawalls and piers, locating submerged debris (moorings and handrails), and determining safe lanes for sea navigation. It provides a preliminary domain theory of postdisaster port and littoral inspection with unmanned vehicles for use by the human–robot interaction community. It was also the first known demonstration of the strongly heterogeneous USV–micro aerial vehicle (MAV) team for any domain. The effort identified cooperative UAV–USV strategies and open issues for autonomous operations near structures. The effort showed that the MAV provided a much‐needed external view for situation awareness and provided spotting for areas to be inspected. Concepts of operations for USV damage inspection and USV–MAV cooperation emerged, including a formula for computing the human–robot ratio: Nh = (2 × Nv) + 1, where Nh is the number of humans and Nv is the number of vehicles. The outstanding research issues span three areas: challenges for USVs operating near littoral structures, general issues for USV–MAV cooperation, and new applications. It is expected that the lessons learned will be transferrable to defense and homeland safety and security applications, such as port security, and other phases of emergency response, including rescue. © 2008 Wiley Periodicals, Inc.
Glutathione adsorption from UHV to the liquid phase at various pH on gold and subsequent modification of protein interaction
Authors: Vallée Anne , Humblot Vincent , Méthivier Christophe , Pradier Claire‐Marie
Published: January 2008

This study is part of a project aiming at a better understanding of polypeptide and protein interactions with a metal surface. A tripeptide (the glutathione, or GSH) was deposited, under ultra high vacuum, on Au (111). From reflection–absorption infrared spectra (RAIRS), GSH was adsorbed in its zwiterrionic form which corresponds to the solid state one. GSH was also adsorbed on Au (111) surfaces from solutions at different pH values. These GSH so‐formed monolayers were then tested to anchor a well‐known protein, the bovine serum albumin (BSA); an effect of the structure and charge of the GSH layers on the protein adsorptions was made clear.

The combination of XPS and polarisation‐modulation (PM)‐RAIRS results showed that the adsorbed GSH is in an identical form as that in solution (ionic state and conformation). When BSA is adsorbed from PBS solutions on the various layers of GSH the anionic or cationic nature of the GSH layer does not influence the adsorption of protein. On the other hand, adsorption of BSA in pure water is strongly favoured on cationic layers. Copyright © 2008 John Wiley & Sons, Ltd.
A novel ATR‐FTIR method for functionalised surface characterisation
Authors: Andersson Per Ola , Lind Per , Mattsson Andreas , Österlund Lars
Published: January 2008

We demonstrate a novel method to analyse ex situ prepared chips by attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR), which circumvents tedious functionalisation steps of internal reflection elements (IREs), and simultaneously allows for complementary measurements by other analytical techniques. This concept is proved by utilising immobilised metal affinity capture (IMAC) chips containing about 10 µm thick films of copolymers coated with nitrilotriacetic acid (NTA) groups. With this so‐called ‘upside‐down’ ATR‐FTIR technique, each chemical modification step can be followed and optimised with respect to concentration, buffer, pH, ionic strength, and so on, and there are no limitations in variations or numbers of functionalised surfaces that can be generated. We have demonstrated the feasibility of this approach to determine the molecular structure of ligand bonded to immobilised polypeptide, directly observed in the raw ATR‐FTIR spectrum. Peptide adsorption in a thick NTA–copolymer matrix yields a high peptide concentration as determined by the analysis of the Langmuir adsorption isotherm. Combined with the ‘upside‐down’ ATR‐FTIR approach which samples the outermost region of the exposed NTA–copolymer film, this generates well‐resolved amide I and II absorption bands that reduce the necessity of using D2O based buffers, which otherwise is common in mid‐IR spectroscopy of proteins. We believe that this new optical surface characterisation method has a great potential as a stand‐alone or complementary analytical tool. We emphasise further that with this approach no chemical treatment of IREs is needed; the chips can be regenerated and reused, and analysed by complementary analytical techniques such as mass spectrometry. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of different primary ion species on the secondary ion emission from PNA/DNA biosensor surfaces
Authors: Hellweg Sebastian , Heile Andreas , Grehl Thomas , Arlinghaus Heinrich F.
Published: January 2008

In recent publications, the use of time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) for a detailed examination of the immobilization process of peptide nucleic acid (PNA) and its hybridization capability to label‐free complementary DNA fragments has been described. Unlabeled single‐stranded DNA was hybridized to biosensor surfaces containing both complementary and noncomplementary PNA sequences. The hybridization of complementary DNA could readily be identified by detecting phosphate‐related molecules from the DNA backbone such as PO3−.

Extending previous measurements on hybridized DNA surfaces using different primary ions and energies, additional ion species have been applied for a more detailed evaluation of the secondary ion emission behavior under static SIMS conditions. The large number of available primary ion species allowed for a comparison between results achieved with ‘classic’ monoatomic and polyatomic ions (such as Ar+, Ga+, Xe+ and SF5+) and bismuth primary ions up to cluster sizes of seven constituents. It was found that the use of polyatomic primary ions in general resulted in a significant increase of secondary ion yields and secondary ion formation efficiencies of DNA‐specific fragments, while the highest values could be achieved with large bismuth cluster ions. It can also be shown that nonlinear effects in projectile‐surface‐excitation are partly responsible for the observed enhancements of yield and efficiency under polyatomic bombardment.

It can be concluded that large bismuth cluster ions are the best choice for detecting hybridized DNA on PNA biosensor chips. Their application optimizes analysis conditions under which TOF‐SIMS provides a useful method for label‐free DNA diagnostics. Copyright © 2008 John Wiley & Sons, Ltd.
Graft photopolymerization of polyethylene glycol monoacrylate (PEGA) on poly(methyl methacrylate) (PMMA) films to prevent BSA adsorption
Authors: Iguerb O. , Bertrand P.
Published: January 2008

This work aims at developing antifouling surfaces. For that purpose, poly(methyl methacrylate) (PMMA) films are surface‐modified by grafting a solution spin‐coated macromonomer, polyethylene glycol monoacrylate (PEGA) under UV irradiation in ambient air. Benzophenone is used as photosensitizer to generate polymer radicals at the surface of the PMMA film. This graft polymerization is carried out onto PMMA substrates pretreated by wet oxidation, with different PEGA formulations. The photografting of PEGA solution is evidenced by Time‐of Flight (ToF)‐SIMS and XPS. Both techniques clearly proved that PEGA is grafted onto preoxidized PMMA substrates. The effect of macromonomer concentration on extent of grafting is investigated. It was found that the amount of grafted PEGA increases by increasing PEGA concentration. Inhibition of protein adhesion by the modified PMMA surfaces is evaluated by XPS and ToF‐SIMS, using, bovine serum albumin (BSA) as model protein. The photografted PMMAox surfaces exhibit excellent protein repellence for high PEGA concentration. Copyright © 2008 John Wiley & Sons, Ltd.
Cytotoxic effects induced by hexachlorobenzene in Squilla mantis (L.) (Crustacea, Stomatopoda)
Authors: Dell'Anno Antonio , Raffaelli Francesca , Danovaro Roberto , Nanetti Laura , Vignini Arianna , Moroni Cinzia , Mazzanti Laura
Published: January 2008

Contamination of marine environments by hexachlorobenzene (HCB) represents a serious concern for potential consequences on ecosystem and human health. Despite this, information on cytotoxic effects on marine organisms is still largely lacking. In this study, we investigated cytotoxic effects induced by HCB on gonads and muscular tissue of Squilla mantis by analysing Na+/K+‐ATPase activity and plasma membrane fluidity. This crustacean species was selected as a model for its habitat, trophic level, feeding behavior, and commercial exploitation for human consumption. Time course experiments revealed that low concentrations of HCB (i.e. 50 nM) determine an exponentially decrease of Na+/K+‐ATPase activity and a significant modification of cellular membrane fluidity. Significant negative relationships between Na+/K+‐ATPase activity and membrane fluidity were observed, suggesting that changes in the structure and packing of cellular membranes induced by HCB may be the primary factor affecting the activity of essential bilayer‐associated enzymes. Overall these findings suggest that even small concentrations of HCB may determine important changes on cell metabolism with potential cascade effects on recruitment of this commercial species. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Protective effect of green tea polyphenols on tributyltin‐induced oxidative damage detected by in vivo and in vitro models
Authors: Liu Huigang , Guo Zonglou , Xu Lihong , Hsu Stephen
Published: January 2008

The current study investigated the protective effects of green tea polyphenols (GTPP) on TBT‐induced oxidative damage. The results showed that reactive oxygen species (ROS) production and malondialdehyde content of the liver in mice exposed to TBT were reduced in the GTPP‐treated group compared to the untreated group. The intracellular ROS level was elevated in TBT‐treated human FL cells in a time‐dependent manner. Comet assay data demonstrated that the number of cells with damaged DNA in untreated mice was found to be significantly higher compared to GTPP‐treated mice. Damage to the nuclei and mitochondria observed in TBT‐treated mice were alleviated in mice treated with both TBT and GTPP. The results represent the first observation that GTPP were effective in reducing TBT‐induced oxidative damage both in vivo and in vitro. The possible protective mechanism may be due to the powerful ability of GTPP to scavenge ROS and prevent DNA breaks. We conclude that GTPP could be an effective agent or food supplement to reduce the cytotoxicity of TBT. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Physiological responses of Matricaria chamomilla to cadmium and copper excess
Authors: Kováčik Jozef , Bačkor Martin , Kaduková Jana
Published: January 2008

Physiological responses of Matricaria chamomilla plants exposed to cadmium (Cd) and copper (Cu) excess (3, 60, and 120 μM for 7 days) with special emphasis on phenolic metabolism were studied. Cu at 120 μM reduced chamomile growth, especially in the roots where it was more abundant than Cd. Notwithstanding the low leaf Cu amount (37.5 μg g−1 DW) in comparison with Cd (237.8 μg g−1 DW) at 120 μM, it caused reduction of biomass accumulation, Fv/Fm ratio and soluble proteins. In combination with high accumulation of phenolics, strong reduction of proteins and high GPX activity in the roots, this supports severe redox Cu properties. In terms of leaf phenylalanine ammonia‐lyase (PAL) activity, it seems that Cd had a stimulatory effect during the course of the experiment, whereas Cu was found to stimulate it after 7‐day exposure. The opposite trend was visible in the roots, where Cd had a stimulatory effect at high doses but Cu mainly at the highest dose. This supports the assumption of different PAL time dynamics under Cd and Cu excess. A dose of 60 and 120 μM Cu led to 2‐ and 3‐times higher root lignin accumulation while the same Cd doses increased it by 33 and 68%, respectively. A Cu dose of 120 μM can be considered as limiting for chamomile growth under conditions of present research, while resistance to high Cd doses was confirmed. However, PAL and phenolics seemed to play an important role in detoxification of Cd‐ and Cu‐induced oxidative stress. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Acute effects of microcystins on the transcription of antioxidant enzyme genes in crucian carp Carassius auratus
Authors: Sun Yuhua , Tang Rong , Li Dapeng , Zhang Xuzhen , Fu Juan , Xie Ping
Published: January 2008

Recent evidences suggested that oxidative stress may play a significant role in the pathogenesis of MCs toxicity. In the present study, the acute effects of microcystins on the transcription of antioxidant enzyme genes were investigated in liver of crucian carp i.p.‐injected with 50 μg MC‐LReq per kg body weight (BW). We reported the cDNA sequences for four kinds of antioxidant enzyme (GSH‐PX, CAT, Cu/Zn SOD, and GR) genes, and evaluated the oxidant stress induced by MCs through analyzing the transcription abundance of antioxidant enzyme genes using real‐time PCR method. The time‐dependent change of relative transcription abundance and expression of the antioxidant enzyme genes were determined at 1, 3, 12, 24, and 48 h. The transcription abundance varied among antioxidant enzymes, with GSH‐PX and GR down‐regulation, and CAT and SOD significantly upregulation. Based on these data, we tentatively concluded that the oxidant stress was induced by MCs, and caused the different response of the antioxidant enzyme genes. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Organochlorine residues in the blubber and liver of bottlenose dolphins (Tursiops truncatus) stranded in the Canary Islands, North Atlantic Ocean
Authors: Carballo Matilde , Arbelo Manuel , Esperón Fernado , Mendez Mariña , de la Torre Ana , Muñoz Maria Jesus
Published: January 2008

Polychlorinated biphenyls (PCBs) and chlorinated pesticides: dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordanes (CHLs), dieldrin, and hexaclorobenzene (HCB) were detected in the blubber and liver of 11 bottlenose dolphins (Tursiops truncatus) from the Canary Islands (North Atlantic Ocean). Samples were obtained from stranded dolphins over the period 1997–2005. Among the organochlorines analyzed, PCBs and DDTs were predominant in the two tissues, followed in decreasing order by chlordane, trans‐nonachlor > cis‐nonachlor > dieldrin and HCB. The sum 11 PCBs in the blubber ranged between 301 and 33,212 ng g−1 ww (990 and 136,679 ng g−1 lw). Highly chlorinated PCBs such us CB153, CB180, and CB138 were the prominent congeners, accounting for 51% of the total PCBs. The sum DDT concentration in the blubber ranged between 147 and 21,050 ng g−1 ww. (490–105,250 ng g−1 lw) The main DDT metabolite was p,p′‐DDE, representing 83% of DDTs in the blubber. In general, the levels of PCBs and DDTs detected were similar to those found in bottlenose dolphins in the North of Europe. The 2,3,7,8‐TCDD toxic equivalent (TEQ) in blubber and liver was calculated for the toxicity assessment of mono‐ortho substituted PCBs congeners (CB105, CB118, CB156). It is important to mention that TEQ values and p,p′‐DDE concentration in adult male specimens are approaching the levels associated with adverse effects found in marine mammals. The information provided represents the first tissue loads of organochlorine compounds in small cetaceans from this area. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Dechlorination with sodium thiosulfate affects the toxicity of wastewater contaminated with copper, cadmium, nickel, or zinc
Authors: Oh So‐Rin , Kim Jung‐Kon , Lee Min‐Jung , Choi Kyungho
Published: January 2008

Sodium thiosulfate is recommended by U.S. Environmental Protection Agency for dechlorination of the effluent samples containing residual chlorines before the toxicity testing. For samples contaminated with residual chlorine and metals, e.g., Cd(II), Cu(II) and Ni(II); however, metal toxicity as measured with Daphnia magna was reduced even at approximately half the recommended amount of sodium thiosulfate. Formation of metal‐thiosulfate complexes that are less bioavailable may explain the apparent reduction of metal toxicity. In contrast, for samples spiked with Zn(II), dechlorination with sodium thiosulfate increased toxicity. The use of sodium thiosulfate for dechlorination should be cautioned when the sample under the bioassay is potentially contaminated with metals. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Effects of the insecticides malathion and diazinon on the early oogenesis in mice in vitro
Authors: Bonilla Edmundo , Hernández Fidel , Cortés Leticia , Mendoza Miriam , Mejía Joel , Carrillo Edgar , Casas Eduardo , Betancourt Miguel
Published: January 2008

Malathion and diazinon are two of the most commonly used organophosphorous (OP) agrochemicals. Several studies show that these pesticides exert several effects on mammalian spermatogenesis. Nevertheless, there are no studies concerning their effects on oogenesis. The objective of this study was to evaluate the effects of these insecticides on the viability of in vitro cultured mouse oocytes during the early oogenesis and to get a further understanding of the molecular mechanisms by which OP insecticides act and affect germinal cells. Oocytes were cultured from fetal ovaries for 10 days, when most oocytes had reached the diplotene stage (germinal vesicle stage). Cultures were exposed to different concentrations of malathion or diazinon for 24 h, and the effect on oocyte viability was assessed. Gene expression in oocytes exposed to the insecticides was analyzed by generating cDNA libraries and performing differential screenings. Results show a significant decrease in oocytes survival after 24‐h exposure to 250 μM malathion or 900 nM diazinon, and the effect of these insecticides on the regulation of genes encoding proteins involved in transcription (BP75), translation (ribosomal protein S5), and mitochondrial function (cytochrome oxidase subunits I and III), providing evidence for OP insecticides as toxicants for mammals oocytes during the early oogenesis. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
cDNA cloning and expression of a xenobiotic metabolizing cytochrome P4501A (CYP1A) from the yellow catfish, Pelteobagrus fulvidraco (Siluriformes)
Authors: Kim Jin‐Hyoung , Hwang Dae‐Sik , Son Kyu‐Hee , Raisuddin Sheikh , Ki Jang‐Seu , Lee Jae‐Seong , Han Kyung‐Nam
Published: January 2008

We cloned the full‐length cDNA sequence of xenobiotic metabolizing cytochrome P4501A (CYP1A) gene from the yellow catfish (Pelteobagrus fulvidraco, Siluriformes, Bagridae). P. fulvidraco is a commercially important fish generally distributed in Southeast Asian countries and Korea. This is the first report of any xenobiotic metabolizing gene from this fish species. Tissue distribution of CYP1A was studied by real‐time PCR. Induction pattern of CYP1A was studied by exposing fish to β‐naphthoflavone (BNF). Liver showed the highest level of expression in control as well as BNF‐treated fish. However, high levels of expression were also recorded in brain, intestine, and kidney and the least in the muscles. Information on CYP genes in fish from order Siluriformes is limited as compared with other fish orders. This study provides an insight into the xenobiotic metabolizing system of P. fulvidraco and offers baseline information for further research related to biomarker use of CYP1A and detoxification strategies of this commercially important fish species. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Risk assessment of herbicide mixtures in a large European lake
Authors: Chèvre Nathalie , Edder Patrick , Ortelli Didier , Tatti Elisa , Erkman Suren , Rapin François
Published: January 2008

Lake Geneva is one of the largest European lakes with a surface area of 580 km2. Its catchment area covers 7400 km2, of which ∼20% is arable land. Monitoring campaigns have been carried out in 2004 and 2005 to determine the contamination of the lake by pesticides. The results highlight the widespread presence of herbicides in water, the measured concentrations for most substances remaining constant in 2004 and 2005. However, for some individual herbicides the concentrations increased drastically (e.g., the herbicide foramsulfuron). We assessed the environmental risk of the herbicides detected in the lake using water quality criteria recently determined for the Swiss environmental protection agency. Furthermore, we assessed the risk of herbicide mixtures, grouped based upon their mode of action. Generally, the risk estimated for all single substances is low, except for some sulfonylurea compounds. For these substances, the measured concentrations are higher than the predicted no‐effect concentration. Impact on the flora of the lake can therefore not be excluded. When mixtures of pesticides with similar mode of action are taken into account, the risk remains lower than the mixture water quality criteria for all groups, but can reach as high as one third of this quality criteria. A further step would therefore be to assess the risk of the total pesticide mixture, including similar and dissimilar modes of action. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Disruption effects of monophthalate exposures on inter‐Sertoli tight junction in a two‐compartment culture model
Authors: Zhang Yun‐Hui , Lin Ling , Liu Zhi‐Wei , Jiang Xue‐Zhi , Chen Bing‐Heng
Published: January 2008

Phthalates are suspect environmental endocrine disruptors that may affect male reproduction and development by disturbing androgen synthesis and cell–cell interactions in the seminiferous epithelium. The in vivo metabolites, monophthalates, are thought to be the active agents, and toxicant effects including testicular damage and decreased sperm motility have been described previously. In this study, the aim was to investigate the effect of monophthalates on Sertoli cells using a two‐compartment cell culture model, asking whether tight junction protein structures are affected, compromising the blood‐testis barrier and contributing to male‐mediated toxicity. Sertoli cells were isolated from Sprague Dawley rat testes and seeded onto the filters of two‐compartment wells. A Sertoli cell monolayer was allowed to form, whereupon the cultures were treated with 0, 10, 30, 150, and 600 μmol/L monobutyl phthalate (MBP) or mono‐2‐ethylhexyl phthalate (MEHP) for 24 h. Effects on the tight junctions between adjacent Sertoli cells were studied by light and transmission electron microscopy, the transepithelial electrical resistance (TEER) assay, and immunofluorescence localization. Results showed that exposures to monophthalates destroyed tight junctional structure in Sertoli cell monolayers in a dose‐depended manner, as evidenced by a loss of single‐cell layer organization in the cultures, decline of TEER value, and decreased expression of proteins associated with tight junctions such as zonula occludens‐1 (ZO‐1), F‐actin, and Occludin. The changes were observed at doses of 150 and 600 μmol/L, which is 10–100 times higher relative to estimated human exposures from the environment. These results are consistent with monophthalate‐induced damage to tight junctions between adjacent Sertoli cells, suggesting that damage to Sertoli cell tight junctions induced by monophthalates may be an underlying mechanism of their male‐mediated reproductive toxicity. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Chronic nickel‐induced DNA damage and cell death: The protection role of ascorbic acid
Authors: Jia Jie , Chen Jie
Published: January 2008

High consumption of nickel‐containing products leads to more exposure of humans to nickel and its by‐products. Except the lethal effect of acute nickel poison, chronic nickel exposure is also harmful to humans, but the mechanism of chronic nickel‐induced cytotoxicity remains unclear. Here, we found that long‐term exposure of Ni2+ led to significant DNA fragmentation, cell death, and reactive oxygen species (ROS) generation in human leukemia HL‐60 cells. Induction of Ni2+ on DNA fragmentation and cell death could be prevented by the antioxidants ascorbic acid (ASA) or N‐acetyl‐cysteine (NAC), or enhanced by H2O2, indicating the involvement of ROS generation in the chronic nickel cytotoxicity in cells. Long‐term exposure of mice to low Ni2+ also led to a significant increase in both the ROS generation in the serum and the DNA fragmentation in the peripheral blood mononuclear cells (PBMC), while coadministration of ASA with Ni2+ together significantly decreased both the DNA fragmentation and the ROS generation. Collectively, these results proved that ROS generation is at least one mechanism of the cytotoxicity of chronic nickel exposure, while ASA is probably useful for people to prevent the chronic nickel cytotoxicity, especially for those who work or live near a mining area or a factory related with nickel. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Elucidating the factors influencing the biodegradation of cylindrospermopsin in drinking water sources
Authors: Smith Maree J. , Shaw Glen R. , Eaglesham Geoff K. , Ho Lionel , Brookes Justin D.
Published: January 2008

The cyanotoxin cylindrospermopsin (CYN) is produced by several species of cyanobacteria and can be persistent in drinking waters supplies, which is of major concern to water authorities because of its potential to severely compromise human health. Consequently, there is a need to fully understand the persistence of CYN in water supplies, in particular, to determine whether this toxin is readily degraded by endemic aquatic organisms. This study provides insights into the environmental factors that can influence the biodegradation of this toxin in Australian drinking water supplies. Biodegradation of CYN was only evident in water supplies that had a history of toxic Cylindrospermopsis raciborskii blooms. In addition, lag periods were evident prior to the onset of biodegradation; however, repeated exposure of the endemic organisms to CYN resulted in substantial decreases in the lag periods. Furthermore, the concentration of CYN was shown to influence biodegradation with a near linear relationship (R2 of 0.9549) existing between the biodegradation rate and the initial CYN concentration. Temperature was also shown to affect the biodegradation of CYN, which is important since CYN is now being detected in more temperate climates. The presence of copper‐based algicides inhibited CYN degradation, which has significant implications since copper‐based algicides are commonly used to control cyanobacterial growth in water bodies. The results from this study indicate that the biodegradation of CYN in natural water bodies is a complex process that can be influenced by many environmental factors, some of which include CYN concentration, temperature, and the presence of copper‐based algicides. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Brine shrimp bioassay: Importance of correct taxonomic identification of Artemia (Anostraca) species
Authors: Ruebhart David R. , Cock Ian E. , Shaw Glen R.
Published: January 2008

Despite the common use of the brine shrimp bioassay in toxicology, there is confusion in the literature regarding citation of the correct taxonomic identity of the Artemia species used. The genus Artemia, once thought to be represented by a single species Artemia salina, is now known to be composed of several bisexual species as well as parthenogenetic populations. Artemia franciscana is the best studied of the Artemia species and is considered to represent the vast majority of studies in which Artemia is used as an experimental test organism. We found that in studies referring to the use of A. salina, the zoogeography of the cyst harvest site indicated that the species used was actually A. franciscana. Those performing bioassays with Artemia need to exercise diligence in assigning correct species identification, as the identity of the test organism is an important parameter in assuring the validity of the results of the assay. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Effects of cypermethrin, propetamphos, and combination involving cypermethrin and propetamphos on lipid peroxidation in mice
Authors: Kanbur Murat , Liman Bilal Cem , Eraslan Gokhan , Altinordulu Sule
Published: January 2008

Insecticides are the chemicals widely used in agriculture, environmental health, human‐and animal‐health fields. Exposure to insecticides has been associated with many hazardous effects, including antioxidative metabolism. In the current study, the effect of cypermethrin (CYP), propetamphos (PRO) and their mixtures on oxidative stress in mice to understand the possible health effects to animals and human beings was investigated. In the present study, 245 male Albino mice weighing 35–40 g were used. The mice were divided into seven groups. The first group served as the control group. The second and third groups were administered CYP at doses of 5 mg/kg/bw and 10 mg/kg/bw, respectively, and the fourth and fifth groups were given PRO at doses of 2.5 mg/kg/bw and 5.0 mg/kg/bw, respectively. The sixth and seventh groups received combination regimens containing 5 mg/kg/bw CYP plus 2.5 mg/kg/bw PRO and 10 mg/kg/bw CYP plus 5 mg/kg/bw PRO, respectively, in feed for 60 days. Blood samples were collected by cardiac puncture on the 15th, 45th and 60th days. Serum nitric oxide (NO) and plasma malondialdehyde (MDA) levels and erythrocyte superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH‐Px) activities were measured. In conclusion, the alterations observed in the MDA and NO levels and SOD, CAT, and GSH‐Px activities of the trial groups, demonstrate the administration of certain doses of CYP and PRO, either alone or combined, to mice for a period of 60 days to produce oxidative stress. The degree of oxidative stress was found to be related to the dose administered, the duration of exposure and the administration of the indicated compounds either alone or as a combination. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Clinical Outcome of Pylorus‐preserving Gastrectomy in Gastric Cancer in Comparison with Conventional Distal Gastrectomy with Billroth I Anastomosis
Authors: Park Do Joong , Lee Hyuk‐Joon , Jung Hyun Chae , Kim Woo Ho , Lee Kuhn Uk , Yang Han‐Kwang
Published: February 2008

Background

Pylorus‐preserving gastrectomy (PPG) was originally a treatment option in gastric ulcer surgery and is now being performed as a limited surgery in some early gastric cancer cases. This study was designed to evaluate the postoperative functional characteristics of PPG versus conventional distal gastrectomy with Billroth I anastomosis (BI).

Methods

Patients who underwent PPG (study group) between November 1999 and April 2003 were enrolled and BI patients (control group) were matched for number, gender, age, weight, height, stage, and follow‐up period. We evaluated postprandial symptoms and nutritional status. Gastric emptying studies with a 99mTc gamma camera, follow‐up endoscopies with random biopsies of remnant gastric mucosa to evaluate bile reflux gastritis, and ultrasonography to detect gallbladder stones were performed. Recurrence and survival also were investigated.

Results

Twenty‐two PPG patients (study group) and 17 BI patients (control group) were enrolled. Overall modified Visick scores of postprandial symptoms were lower in PPG patients than in BI patients (0.9 ± 0.7 vs. 2.3 ± 1.4; p = 0.018). Gastric emptying was delayed in PPG patients versus BI patients for solids (p < 0.05). Moderate gastritis, bile reflux, and gallbladder stone were observed only in BI patients. Remnant stomach pathologic findings corresponding to bile reflux gastritis in the two groups were similar, except for Helicobacter pylori colonization. No recurrence occurred in either group (mean follow‐up period = 41 ± 9.5 months).

Conclusions

PPG patients had fewer subjective postprandial symptoms than BI patients. The present study also suggests that PPG has advantages over BI in terms of the avoidance of bile reflux and gallbladder stones.
From Racecourse to People’s Park and People’s Square: The historical changes and the symbolic meaning
Authors: Yuezhi XIONG
Published: February 2008

Shanghai Racecourse was established at 1850, it was finally transformed into People’s Park and People’s Square in 1951. The Racecourse was originally just a simple recreational center. However, with the change of its own function and the trend of thought, it changed into a casino of cheating and murder, a place of discrimination against Chinese, a stage for the imperialists to show off their power and violence and a symbol of all evil things. The appeal to change the Racecourse echoed to the demand of opposing imperialism, taking back the concession, desire for civilization and democracy. From 1930s to 1950s, even though great change took place in the ruling party and the political power, there was an obvious continuity in the domain of thought and ideology.
Motor-skill learning in older adults—a review of studies on age-related differences
Authors: Voelcker-Rehage Claudia
Published: January 2008

This paper reviews research on motor-skill learning across the life span with particular emphasis on older age. For this purpose, studies that focus on age-related differences in fine and gross motor skills and studies that analyze the further refinement of known skills as well as learning of unknown motor skills are summarized. The reviewed studies suggest that although motor performance tends to decline in old age, learning capabilities remain intact, and older adults are able to achieve considerable performance gains. The extent to which the learning capability varies with age, however, has to be considered very carefully. While most studies revealed that performance gains in fine motor tasks are diminished in older adults, results for gross-motor-skill learning are more contradictory. Additionally, there is considerable agreement on the finding that age-related learning differences are statistically more robust in complex tasks, whereas in low-complexity tasks, the learning of younger and older adults is very similar. This applies to fine and gross motor skills. Relative age differences seem to become enlarged when effortful resources are required for motor performance. Thus, the decline in motor learning that accompanies aging is task specific and not absolute.
Genetic Regulation of Embryological Limb Development with Relation to Congenital Limb Deformity in Humans
Authors: Barham Guy , Clarke Nicholas M. P.
Published: February 2008

Over the last 15 years, great improvements in genetic engineering and genetic manipulation strategies have led to significant advances in the understanding of the genetics governing embryological limb development. This field of science continues to develop, and the complex genetic interactions and signalling pathways are still not fully understood. In this review we will discuss the roles of the principle genes involved in the three-dimensional patterning of the developing limb and will discuss how errors in these signalling cascades correlate to congenital limb deformity in humans. This review is aimed at orthopaedic surgeons wishing to understand the principles of congenital limb deformity related to genetic signalling errors. It is by no means a comprehensive study of the molecular genetics governing the complex interactions involved in each step of limb development. There are however many syndromes involving limb deformity for which the molecular causes are unknown.
The dosage of chromatin proteins affects transcriptional silencing and DNA repair in Saccharomyces cerevisiae
Authors: Benbow Sarah Z. , DuBois Michelle L.
Published: January 2008

Alterations in protein composition or dosage within chromatin may trigger changes in processes such as gene expression and DNA repair. Through transposon mutagenesis and targeted gene deletions in haploids and diploids of Saccharomyces cerevisiae, we identified mutations that affect telomeric silencing in genes encoding telomere‐associated Sir4p and Yku80p and chromatin remodeling ATPases Ies2p and Rsc1p. We found that sir4/SIR4 heterozygous diploids efficiently silence the mating type locus HMR but not telomeres, and diploids heterozygous for yku80 and ies2 mutations are inefficient at DNA repair. In contrast, strains heterozygous for most chromatin remodeling ATPase mutations retain wild‐type silencing and DNA repair levels. Thus, in diploids, chromatin structures required for DNA repair and telomeric silencing are sensitive to dosage changes.
The effects of local selection versus dispersal on insecticide resistance patterns: longitudinal evidence from diamondback moth (Plutella xylostella(Lepidoptera: Plutellidae)) in Australia evolving resistance to pyrethroids
Authors: Endersby N.M. , Ridland P.M. , Hoffmann A.A.
Published: January 2008

When strong directional selection acts on a trait, the spatial distribution of phenotypes may reflect effects of selection, as well as the spread of favoured genotypes by gene flow. Here we investigate the relative impact of these factors by assessing resistance to synthetic pyrethroids in a 12-year study of diamondback moth,Plutella xylostella, from southern Australia. We estimated resistance levels in populations from brassicaceous weeds, canola, forage crops and vegetables. Differences in resistance among local populations sampled repeatedly were stable over several years. Levels were lowest in samples from weeds and highest in vegetables. Resistance in canola samples increased over time as insecticide use increased. There was no evidence that selection in one area influenced resistance in adjacent areas. Microsatellite variation from 13 populations showed a low level of genetic variation among populations, with an AMOVA indicating that population only accounted for 0.25% of the molecular variation. This compared to an estimate of 13.8% of variation accounted for by the resistance trait. Results suggest that local selection rather than gene flow of resistance alleles dictated variation in resistance across populations. Therefore, regional resistance management strategies may not limit resistance evolution.
Geotectonic evolution of the Bransfield Basin, Antarctic Peninsula: insights from analogue models
Authors: Solari M.A. , Hervé F. , Martinod J. , Le Roux J.P. , Ramírez L.E. , Palacios C.
Published: January 2008

The Bransfield Strait, located between the South Shetland Islands and the north-western end of the Antarctic Peninsula, is a back-arc basin transitional between rifting and spreading. We compiled a geomorphological structural map of the Bransfield Basin combining published data and the interpretation of bathymetric images. Several analogue experiments reproducing the interaction between the Scotia, Antarctic, and Phoenix plates were carried out. The fault configuration observed in the geomorphological structural map was well reproduced by one of these analogue models. The results suggest the establishment of a transpressional regime to the west of the southern segment of the Shackleton Fracture Zone and a transtensional regime to the south-west of the South Scotia Ridge by at least c. 7 Ma. A probable mechanism for the opening of the Bransfield Basin requires two processes: 1) Significant transtensional effects in the Bransfield Basin caused by the configuration and drift vector of the Scotia Plate after the activity of the West Scotia Ridge ceased at c. 7 Ma. 2) Roll-back of the Phoenix Plate under the South Shetland Islands after cessation of spreading activity of the Phoenix Ridge at 3.3 ± 0.2 Ma, causing the north-westward migration of the South Shetland Trench.
Defining the social phenotype in Williams syndrome: A model for linking gene, the brain, and behavior
Authors: Järvinen-Pasley Anna , Bellugi Ursula , Reilly Judy , MILLS Debra L. , Galaburda Albert , Reiss Allan L. , Korenberg Julie R.
Published: January 2008

Research into phenotype–genotype correlations in neurodevelopmental disorders has greatly elucidated the contribution of genetic and neurobiological factors to variations in typical and atypical development. Etiologically relatively homogeneous disorders, such as Williams syndrome (WS), provide unique opportunities for elucidating gene–brain–behavior relationships. WS is a neurogenetic disorder caused by a hemizygous deletion of approximately 25 genes on chromosome 7q11.23. This results in a cascade of physical, cognitive–behavioral, affective, and neurobiological aberrations. WS is associated with a markedly uneven neurocognitive profile, and the mature state cognitive profile of WS is relatively well developed. Although anecdotally, individuals with WS have been frequently described as unusually friendly and sociable, personality remains a considerably less well studied area. This paper investigates genetic influences, cognitive–behavioral characteristics, aberrations in brain structure and function, and environmental and biological variables that influence the social outcomes of individuals with WS. We bring together a series of findings across multiple levels of scientific enquiry to examine the social phenotype in WS, reflecting the journey from gene to the brain to behavior. Understanding the complex multilevel scientific perspective in WS has implications for understanding typical social development by identifying important developmental events and markers, as well as helping to define the boundaries of psychopathology.
Trajectories of maternal depression over 7 years: Relations with child psychophysiology and behavior and role of contextual risks
Authors: Ashman Sharon B. , Dawson Geraldine , Panagiotides Heracles
Published: January 2008

This study examines the relation between the longitudinal course of maternal depression during the child's early life and children's psychophysiology and behavior at age 6.5 years. One hundred fifty-nine children of depressed and nondepressed mothers were followed from infancy through age 6.5 years. Growth mixture modeling was used to identify classes of depressed mothers based on the longitudinal course of the mother's depression. School-aged children of chronically depressed mothers were found to have elevated externalizing behavior problems, decreased social competence, reduced frontal brain activation (EEG power), and higher respiratory sinus arrhythmia reactivity. Children of mothers with decreasing and stable mild depression were found to have increased hyperactivity and attention problems compared to children of nondepressed mothers. Contextual risk factors were found to mediate the relation between maternal depression and child behavioral outcomes.
Young children's representations of conflict and distress: A longitudinal study of boys and girls with disruptive behavior problems
Authors: Zahn-Waxler Carolyn , Park Jong-Hyo , Usher Barbara , Belouad Francesca , Cole Pamela , Gruber Reut
Published: January 2008

We investigated narratives, symbolic play, and emotions in children who varied in severity of disruptive behavior problems. Children's representations of hypothetical situations of conflict and distress were assessed at 4–5 and 7 years. Behavior problems also were assessed then and again at 9 years. Children's aggressive and caring themes differentiated nonproblem children, children whose problems remained or worsened with age, and those whose problems improved over time. Differences in boys and girls whose problems continued sometimes reflected exaggerations of prototypic gender differences seen across the groups. Boys with problems showed more hostile themes (physical aggression and anger), whereas girls with problems showed more caring (prosocial) themes relative to the other groups. Modulated (verbal) aggression, more common in girls than boys, showed developmentally appropriate increases with age. However, this was true only for children without problems and those whose problems improved. We consider how these findings contribute to an understanding the inner worlds of boys and girls who differ in their early developmental trajectories for behavior problems.
Defining risk heterogeneity for internalizing symptoms among children of alcoholic parents
Authors: Hussong Andrea M. , Flora David B. , Curran Patrick J. , Chassin Laurie A. , Zucker Robert A.
Published: January 2008

Adopting a developmental epidemiology perspective, the current study examines sources of risk heterogeneity for internalizing symptomatology among children of alcoholic parents (COAs). Parent-based factors, including comorbid diagnoses and the number of alcoholic parents in the family, as well as child-based factors, namely child gender, formed the indicators of heterogeneity. Following a novel approach to cross-study methods, we present a three-stage analysis involving measurement development using item response theory, examination of study effects on latent trajectories over time using latent curve modeling, and prediction of these latent trajectories testing our theoretically derived hypotheses in two longitudinal investigations across both mother- and self-reported symptomatology. Specifically, we replicated previous findings that parent alcoholism has a unique effect on child internalizing symptoms, above and beyond those of both parent depression and antisocial personality disorder. However, we also found important subgroup differences, explaining heterogeneity within COAs' risk profile in terms of the number of alcoholic parents in the family, comorbid diagnoses for the alcoholic parent and, for self-reported symptoms, child gender. Such factors serve to refine the definition of risk among COAs, suggesting a more severely impaired target group for preventive interventions, identifying the significance of familial alcoholism in individual differences underlying internalizing symptoms over time, and further specifying the distal risk matrix for an internalizing pathway to alcohol involvement.