Different Modes (different + mode)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Contract Law and the Governance of Inter-Firm Technology Partnerships , An Analysis of Different Modes of Partnering and Their Contractual Implications*

JOURNAL OF MANAGEMENT STUDIES, Issue 3 2007
John Hagedoorn
abstract This paper studies some major legal implications of inter-firm technology partnering through equity joint ventures, non-equity partnerships, and licensing contracts. These different partnerships are placed within the classical and relational contracting perspectives, while also considering intellectual property rights issues. Samples of contracts of partnerships in bioscience, fine chemicals, biotechnology and biopharmaceuticals are analysed, in detail, with reference to the distribution of property rights, major contractual clauses, and measures for conflict resolution. Equity joint ventures and non-equity partnerships are found to largely follow a relational contracting perspective, while licensing contracts are governed by a classical contracting perspective. [source]


A Novel Azulene Synthesis from the Ramirez Ylide Involving Two Different Modes of Its Reaction with Activated Alkynes.

CHEMINFORM, Issue 29 2004
Lee J. Higham
Abstract For Abstract see ChemInform Abstract in Full Text. [source]


Cover Picture: Electrophoresis 7'2010

ELECTROPHORESIS, Issue 7 2010
Article first published online: 26 MAR 2010
Issue no. 7 is a special issue on CE-MS consisting of "19 manuscripts subdivided into three major categories: one devoted to instrumental and methodical advances, two providing an insight into up-to-date applications from the fields of technical and natural products, food and environmental analysis on the one hand and biomedical and pharmaceutical analysis on the other hand. Diverse approaches how CE-MS can be employed for the solution of various analytical problems can be found in these papers. Different modes of electroseparation techniques in the capillary format such as CZE, CEC or MEEKC are coupled to various MS instruments ranging from simple quadrupole MS instruments to state of the art QTOF's, using a range of interfaces such as ESI, ICP or APPI. So this special issue will again try to present an overview of current trends and developments in the fields of CE-MS" [source]


A Density Functional Study of Ethylene Insertion into the M-methyl (M = Ti, Zr) Bond for Different Catalysts, with a QM/MM Model for the Counterion, B(C6F5)3CH3,

ISRAEL JOURNAL OF CHEMISTRY, Issue 4 2002
Kumar Vanka
Single site homogeneous catalysts have been studied extensively in recent years as alternatives to traditional heterogeneous catalysts. The current theoretical study uses density functional theory to study the insertion process of the ethylene monomer into the titanium-carbon chain for contact ion-pair systems of the type [L1L2TiCH3 -,-CH3 -B(C6F5)3], where L1, L2, are Cp, NPH3, and other ligands. Different modes of approach cis and trans to the ,-CH3 bridge were considered. The counterion, B(C6F5)3CH3,, was modeled by QM/MM methods. The value of ,Htot,the total barrier to insertion,was found to be positive (in the range of 4,15 kcal/mol). The ability of the ancillary ligands, L1 and L2, to stabilize the ion-pair was found to be an important factor in determining the value of ,Htot. On replacing the titanium metal center with zirconium, the ,Htot values were found to be lowered (in the range of 2,9 kcal/mol), indicating that they would be better catalysts than their titanium analogues. The size of the ligands L1 and L2 was increased by replacing hydrogens in the ligands with tertiary butyl groups. The value of ,Htot was found to increase (in the range of 10,28 kcal/mol) in contrast to the simple systems, for both the cis and trans cases of approach, with the cis mode of approach giving lower values of ,Htot. Solvent effects were incorporated with cyclohexane (, = 2.023) as the solvent, and were found to have a minor influence, ±(0.5,1.5) kcal/mol) on the insertion barrier for all the cases studied. [source]


Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina-forming alloy.

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 5 2004
Part I: Isothermal oxidation tests
Abstract Different modes of introduction of yttrium have been tested with regard to the influence on the high temperature oxidation behavior of a FeCral alloy. Y2O3 sol-gel coatings, Y2O3 metal-organic chemical vapor deposition (MOCVD) coatings, implanted yttrium ions and yttrium as alloying element (0.1 wt.%) in the same Fe-20Cr-5Al alloy were oxidized at 1100°C in air under atmospheric pressure. Whatever the mode of introduction of the reactive element, the oxidation rates were not decreased compared to the oxidation rate of the blank specimen. The observation of the oxidized surface indicated that the alumina scale largely spalled from the blank alloy. Spallation was reduced for the Y2O3 sol-gel coated, the Y2O3 MOCVD coated alloys and the yttrium ion implanted steels. The Y-containing alloy did not exhibit any detachment of the oxide scale, indicating the best high temperature oxidation behavior, at least from the viewpoint of scale adherence. [source]


Fracture and fatigue study of unidirectional glass/epoxy laminate under different mode of loading

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 5 2010
M. KENANE
ABSTRACT Interlaminar fracture is the dominant failure mechanism in most advanced composite materials. The delaminating behaviour of materials is quantified in terms of the strain energy release rate,G. In this paper, the experimental measurements of the fatigue delaminating growth for some combinations of energy release rate mode ratio have been carried out on unidirectional glass/epoxy laminates. On this base the constants in the Paris equation have been determined for each GII/GT considered modal ratio. The fatigue threshold strain energy release rate ,,GTth, below which delaminating doesn't occur, were measured. Three type specimens were tested, namely: double cantilever beam (DCB), end-loaded split (ELS) and mixed-mode bending (MMB) under mode I, mode II and mixed-mode (I + II) loading, respectively. Scanning electron microscopy techniques were used to identify the fatigue delamination growth mechanisms and to define the differences between the various modes of fracture. [source]


Inhibition of pneumococcal choline-binding proteins and cell growth by esters of bicyclic amines

FEBS JOURNAL, Issue 2 2007
Beatriz Maestro
Streptococcus pneumoniae is one of the major pathogens worldwide. The use of currently available antibiotics to treat pneumococcal diseases is hampered by increasing resistance levels; also, capsular polysaccharide-based vaccination is of limited efficacy. Therefore, it is desirable to find targets for the development of new antimicrobial drugs specifically designed to fight pneumococcal infections. Choline-binding proteins are a family of polypeptides, found in all S. pneumoniae strains, that take part in important physiologic processes of this bacterium. Among them are several murein hydrolases whose enzymatic activity is usually inhibited by an excess of choline. Using a simple chromatographic procedure, we have identified several choline analogs able to strongly interact with the choline-binding module (C-LytA) of the major autolysin of S. pneumoniae. Two of these compounds (atropine and ipratropium) display a higher binding affinity to C-LytA than choline, and also increase the stability of the protein. CD and fluorescence spectroscopy analyses revealed that the conformational changes of C-LytA upon binding of these alkaloids are different to those induced by choline, suggesting a different mode of binding. In vitro inhibition assays of three pneumococcal, choline-dependent cell wall lytic enzymes also demonstrated a greater inhibitory efficiency of those molecules. Moreover, atropine and ipratropium strongly inhibited in vitro pneumococcal growth, altering cell morphology and reducing cell viability, a very different response than that observed upon addition of an excess of choline. These results may open up the possibility of the development of bicyclic amines as new antimicrobials for use against pneumococcal pathologies. [source]


Different hepatitis C virus nonstructural protein 3 (Ns3)-DNA,expressing vaccines induce in HLA-A2.1 transgenic mice stable cytotoxic T lymphocytes that target one major epitope

HEPATOLOGY, Issue 6 2001
Carine Brinster
The immunogenicity of the Hepatitis C virus (HCV) nonstructural protein 3 (NS3) was investigated using different DNA-based strategies and a preclinical mouse model transgenic for the HLA-A2.1 molecule. Plasmids expressing NS3 either as a wild-type protein, as a fusion with murine lysosome-associated-membrane protein-1 specific sequences, or under the control of the Semliki Forest virus replicase were evaluated in vitro and in vivo. All plasmids were shown to express the expected size protein. These 3 NS3-expressing vaccines induced overall comparable levels of CTLs when measured at different times postvaccination although mice injected with the NS3-LAMP expressing plasmid showed a particularly homogeneous and overall vigorous response (specific lysis ranged from 60% to 90 % for an E:T ratio of 33.3:1 with a mean CTL precursor frequency of 1:2.105 cells). Out of the four HLA-A2.1-restricted NS3 epitopes previously described in HCV infected patients (aa 1073-1081, aa 1406-1415; aa 1169-1177 and aa 1287-1296), the NS3-DNA generated CTLs were predominantly targeted at the aa 1073-1081 epitope. Peptide-based immunization showed that the mouse repertoire was intact for all epitopes tested except one (aa 1287-1296). In conclusion, the 3 NS3-DNA vaccines although based on different mode of action, shared a comparable efficacy at inducing CTL. Surprisingly, the breadth of such response was restricted to a single, major epitope. [source]


On Nursing Theories and Evidence

JOURNAL OF NURSING SCHOLARSHIP, Issue 2 2001
Jacqueline Fawcett
Purpose: To expand the understanding of what constitutes evidence for theory-guided, evidence-based nursing practice from a narrow focus on empirics to a more comprehensive focus on diverse patterns of knowing. Organizing construct: Carper's four fundamental patterns of knowing in nursing,empirical, ethical, personal, and aesthetic,are required for nursing practice. A different mode of inquiry is required to develop knowledge about and evidence for each pattern. Conclusions: Theory, inquiry, and evidence are inextricably linked. Each pattern of knowing can be considered a type of theory, and the modes of inquiry appropriate to the generation and testing of each type of theory provide diverse sources of data for evidence-based nursing practice. Different kinds of nursing theories provide different lenses for critiquing and interpreting the different kinds of evidence essential for theory-guided, evidence-based holistic nursing practice. [source]


Gold compounds as anticancer agents: chemistry, cellular pharmacology, and preclinical studies

MEDICINAL RESEARCH REVIEWS, Issue 3 2010
Stefania Nobili
Abstract Gold compounds are a class of metallodrugs with great potential for cancer treatment. During the last two decades, a large variety of gold(I) and gold(III) compounds are reported to possess relevant antiproliferative properties in vitro against selected human tumor cell lines, qualifying themselves as excellent candidates for further pharmacological evaluation. The unique chemical properties of the gold center confer very interesting and innovative pharmacological profiles to gold-based metallodrugs. The primary goal of this review is to define the state of the art of preclinical studies on anticancer gold compounds, carried out either in vitro or in vivo. The available investigations of anticancer gold compounds are analyzed in detail, and particular attention is devoted to underlying molecular mechanisms. Notably, a few biophysical studies reveal that the interactions of cytotoxic gold compounds with DNA are generally far weaker than those of platinum drugs, implying the occurrence of a substantially different mode of action. A variety of alternative mechanisms were thus proposed, of which those involving either direct mitochondrial damage or proteasome inhibition or modulation of specific kinases are now highly credited. The overall perspectives on the development of gold compounds as effective anticancer drugs with an innovative mechanism of action are critically discussed on the basis of the available experimental evidence. © 2009 Wiley Periodicals, Inc. Med Res Rev, 30, No. 3, 550,580, 2010 [source]


Primary productivity can affect mammalian body size frequency distributions

OIKOS, Issue 2 2001
Birgitta Aava
Frequency distributions of mammal body sizes in large-scale assemblages have often been found to show a positive skew. In an attempt to explain this pattern, a model has been put forward which incorporates energetic constraints on fitness and thereby predicts optimal body sizes corresponding to the mode of the distribution. A key assumption of the model is that energy is unlimited. However, if energy is limited, the input of energy into a herbivorous mammal community should influence the shape of the frequency distribution. Thus, I propose that increases in primary productivity will decrease the variation of body size and increase the mean body size in a distribution. So, in low-productivity environments we should see a predominance of small-sized species, but with a great variation of body sizes due to limitations of resources (energy). I tested this hypothesis using the herbivorous mammal fauna (rodents, bats and marsupials) in seven biomes of Australia. Because herbivorous marsupials generally are fairly large-bodied while rodents and bats are small-sized and because marsupials also have a different mode of reproduction from placental mammals, the hypothesis was also tested on placental mammals and marsupials separately. There was no clear mode for the entire assemblage in any biome, but as primary productivity increased, the variation of body masses decreased and the mean body mass of the distribution increased. Body mass distributions of both placental mammals and marsupials displayed clear modes. Placental mammals also showed an increase in mean body mass. The variation in body mass of marsupials was highest for the intermediately productive biomes. Primary productivity does seem to have some effect on mammalian body mass in this case, but the results here need to be complemented with studies of other assemblages before any general conclusions can be drawn. It is also important to distinguish which taxa are affected in a heterogeneous assemblage like the Australian herbivorous mammal fauna. [source]


Comparative analysis of neonicotinoid binding to insect membranes: I. A structure,activity study of the mode of [3H]imidacloprid displacement in Myzus persicae and Aphis craccivora

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2004
Dr Hartmut Kayser
Abstract Neonicotinoids bind selectively to insect nicotinic acetylcholine receptors with nanomolar affinity to act as potent insecticides. While the members of the neonicotinoid class have many structural features in common, it is not known whether they also share the same mode of binding to the target receptor. Previous competition studies with [3H]imidacloprid, the first commercialised neonicotinoid, indicated that thiamethoxam, representing a novel structural sub-class, may bind in a different way from that of other neonicotinoids. In the present work we analysed the mode of [3H]imidacloprid displacement by established neonicotinoids and newly synthesized analogues in the aphids Myzus persicae Sulzer and Aphis craccivora Koch. We found two classes of neonicotinoids with distinct modes of interference with [3H]imidacloprid, described as direct competitive inhibition and non-competitive inhibition, respectively. Competitive neonicotinoids were acetamiprid, nitenpyram, thiacloprid, clothianidin and nithiazine, whereas thiamethoxam and the N -methyl analogues of imidacloprid and clothianidin showed non-competitive inhibition. The chloropyridine or chlorothiazole heterocycles, the polar pharmacophore parts, such as nitroimino, cyanoimino and nitromethylene, and the cyclic or acyclic structure of the pharmacophore were not relevant for the mode of inhibition. Consensus structural features of the neonicotinoids were defined for the two mechanisms of interaction with [3H]imidacloprid binding. Furthermore, two sub-classes of non-competitive inhibitors can be discriminated on the basis of their Hill coefficients for imidacloprid displacement. We conclude from the present data that the direct competitors share the binding site with imidacloprid, whereas non-competitive compounds, like thiamethoxam, bind to a different site or in a different mode. Copyright © 2004 Society of Chemical Industry [source]


Pseudomonas putida KT2440 responds specifically to chlorophenoxy herbicides and their initial metabolites

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 11 2006
Dirk Benndorf Dr.
Abstract Pseudomonas putida,KT2440 is often used as a model to investigate toxicity mechanisms and adaptation to hazardous chemicals in bacteria. The objective of this paper was to test the impact of the chlorophenoxy herbicides 2,4-dichlorophenoxyacetic acid,(2,4-D) and 2-(2,4-dichlorophenoxy)propanoic acid,(DCPP) and their metabolites 2,4-dichlorophenol,(DCP) and 3,5-dichlorocatechol,(DCC), on protein expression patterns and physiological parameters. Both approaches showed that DCC has a different mode of action and induces different responses than DCPP, 2,4-D and DCP. DCC was the most toxic compound and was active as an uncoupler of oxidative phosphorylation. It repressed the synthesis of ferric uptake regulator (Fur)-dependent proteins, e.g. fumarase,C and L -ornithine N5-oxygenase, which are involved in oxidative stress response and iron uptake. DCPP, 2,4-D and DCP were less toxic than DCC. They disturbed oxidative phosphorylation to a lesser extent by a yet unknown mechanism. Furthermore, they repressed enzymes of energy-consuming biosynthetic pathways and induced membrane transporters for organic substrates. A TolC homologue component of multidrug resistance transporters was found to be induced, which is probably involved in the removal of lipophilic compounds from membranes. [source]


N,N,N,,N,-Tetra­methyl­ethyl­ene­diammonium,succinate,succinic acid (1/1/1)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2004
Giuseppe Bruno
In the title compound, C6H18N22+·C4H4O42,·C4H6O4, the components lie on centres of symmetry in space group , such that the asymmetric unit contains three half-mol­ecules. Despite the different mode (with respect to other di­carboxylic acids) adopted by the intermolecular self-interaction of succinic acid derivatives, the overall structure of the title compound consists of anionic layers that are typical of the packing structures exhibited by other di­carboxylic acid analogues. [source]


The structure of Staphylococcus aureus phosphopantetheine adenylyltransferase in complex with 3,-phosphoadenosine 5,-phosphosulfate reveals a new ligand-binding mode

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 10 2009
Hyung Ho Lee
Bacterial phosphopantetheine adenylyltransferase (PPAT) catalyzes the penultimate step in the coenzyme A (CoA) biosynthetic pathway. It catalyzes the reversible transfer of an adenylyl group from ATP to 4,-phosphopantetheine (Ppant) to form dephospho-CoA (dPCoA) and pyrophosphate. Previous structural studies have revealed how several ligands are recognized by bacterial PPATs. ATP, ADP, Ppant and dPCoA bind to the same binding site in a highly similar manner, while CoA binds to a partially overlapping site in a different mode. To provide further structural insights into ligand binding, the crystal structure of Staphylococcus aureus PPAT was solved in a binary complex with 3,-phosphoadenosine 5,-phosphosulfate (PAPS). This study unexpectedly revealed a new mode of ligand binding to PPAT, thus providing potentially useful information for structure-based discovery of inhibitors of bacterial PPATs. [source]


Interaction of an echinomycin,DNA complex with manganese ions

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2009
Roland Pfoh
The crystal structure of an echinomycin,d(ACGTACGT) duplex interacting with manganese(II) was solved by Mn-SAD using in-house data and refined to 1.1,Å resolution against synchrotron data. This complex crystallizes in a different space group compared with related complexes and shows a different mode of base pairing next to the bis-intercalation site, suggesting that the energy difference between Hoogsteen and Watson,Crick pairing is rather small. The binding of manganese to N7 of guanine is only possible because of DNA unwinding induced by the echinomycin, which might help to explain the mode of action of the drug. [source]


Inhibition of Cyclooxygenases by Dipyrone

BRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2007
S C Pierre
Background and Purpose: Dipyrone is a potent analgesic drug that has been demonstrated to inhibit cyclooxygenase (COX). In contrast to classical COX-inhibitors, such as aspirin-like drugs, dipyrone has no anti-inflammatory effect and a low gastrointestinal toxicity, indicating a different mode of action. Here, we aimed to investigate the effects of dipyrone on COX. Experimental approach: The four major metabolites of dipyrone, including the two pharmacologically active metabolites, 4-methyl-amino-antipyrine (MAA) and amino-antipyrine (AA), were used to characterise their binding to COX and haem as well as their effects on the biochemical properties of COX. Mass spectrometry, UV and visible photometry were used to study binding and prostaglandin production. Levels of anti-oxidant enzymes were assessed by Western blotting. Key results: The pharmacologically active metabolites of dipyrone, MAA and AA, did not inhibit COX activity in vitro like classical COX inhibitors, but instead redirected the prostaglandin synthesis, ruling out inhibition of COX through binding to its active site. We found that MAA and AA formed stable complexes with haem and reacted with hydrogen peroxide in presence of haem, ferrous ions (Fe2+) or COX. Moreover, MAA reduced Fe3+ to Fe2+ and accordingly increased lipid peroxidation and the expression of anti-oxidant enzymes in cultured cells and in vivo. Conclusions and implications: Our data suggest that the pharmacologically active metabolites of dipyrone inhibit COX activity by sequestering radicals which initiate the catalytic activity of this enzyme or through the reduction of the oxidative states of the COX protein. British Journal of Pharmacology (2007) 151, 494,503; doi:10.1038/sj.bjp.0707239 [source]


Caspofungin,a new therapeutic option for oropharyngeal candidiasis

CLINICAL MICROBIOLOGY AND INFECTION, Issue 3 2004
J. Garbino
Abstract Patients with AIDS are often severely immunocompromised. These patients commonly develop opportunistic infections such as oropharyngeal candidiasis whose treatment may prove to be difficult. Caspofungin belongs to a new class of antifungal agents that have a different mode of action to azoles and polyenes. This new agent is the first inhibitor of fungal glucan synthesis to receive approval for the treatment of mucosal and invasive candidiasis and invasive aspergillosis. Caspofungin is well-tolerated and represents a substantial improvement over existing therapeutic options for patients prone to azole-resistant candida infection or who cannot tolerate amphotericin B. [source]


Distributed computing with Triana on the Grid

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 9 2005
Ian Taylor
Abstract In this paper, we describe Triana, a distributed problem-solving environment that makes use of the Grid to enable a user to compose applications from a set of components, select resources on which the composed application can be distributed and then execute the application on those resources. We describe Triana's current pluggable architecture that can support many different modes of operation by the use of flexible writers for many popular Web service choreography languages. We further show, that the Triana architecture is middleware-independent through the use of the Grid Application Toolkit (GAT) API and demonstrate this through the use of a GAT binding to JXTA. We describe how other bindings being developed to Grid infrastructures, such as OGSA, can seamlessly be integrated within the current prototype by using the switching capability of the GAT. Finally, we outline an experiment we conducted using this prototype and discuss its current status. Copyright © 2005 John Wiley & Sons, Ltd. [source]


BEHAVIOR GENETICS AND ANOMIE/STRAIN THEORY

CRIMINOLOGY, Issue 4 2000
ANTHONY WALSH
Criminology is in need of conceptual revival, and behavior genetics can provide the concepts and research design to accomplish this. Behavior genetics is a biologically-friendly environmental discipline that often tells us more about environmental effects on individual traits than about genetic effects. Anomie/strain theory is used to illustrate the usefulness of behavior genetics to criminological theories. Behavior genetics examines the individual differences that sort people into different modes of adaptation and that lead them to cope constructively or destructively with strain. Behavior genetics and other biosocial perspectives have the potential to help illuminate Agnew's (1997) extension of General Strain Theory (GST) into the developmental realm. [source]


Caveolin-1 polarization in migrating endothelial cells is directed by substrate topology not chemoattractant gradient

CYTOSKELETON, Issue 11 2006
Virginie Santilman
Abstract Polarization is a hallmark of migrating cells, and an asymmetric distribution of proteins is essential to the migration process. Caveolin-1 is highly polarized in migrating endothelial cells (EC). Several studies have shown caveolin-1 accumulation in the front of migrating EC while others report its accumulation in the EC rear. In this paper we address these conflicting results on polarized localization of caveolin-1. We find evidence for the hypothesis that different modes of locomotion lead to differences in protein polarization. In particular, we show that caveolin-1 is primarily localized in the rear of cells migrating on a planar substrate, but in the front of cells traversing a three-dimensional pore. We also show that a chemoattractant, present either as a gradient or ubiquitously in the medium, does not alter caveolin-1 localization in cells in either mode of locomotion. Thus we conclude that substrate topology, and not the presence of a chemoattractant, directs the polarization of caveolin-1 in motile ECs. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc. [source]


How does the brain learn language?

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 2 2000
Insights from the study of children with, without language impairment
Neurobiological studies have generated new ways of thinking about development of brain structure and function. Development involves more than just growth from simple to complex structures. The initial over-abundance of neurons and synaptic connections is subsequently pruned of those that are non-functional. In addition, as behavioural and cognitive functions emerge and become automatized, the underlying brain representations are reorganized. In this paper, I shall argue that these different modes of neurodevelopmental change provide a useful metaphor for examining language acquisition. It will be argued that language acquisition can involve learning to ignore and inhibit irrelevant information, as well as forming new ways of representing complex information economically. Modular organization is not present from the outset, but develops gradually. This analysis suggests a new way of assessing specific language impairment (SLI). There has been much debate as to whether children with SLI lack specific modular components of a language processing system. I propose instead that these children persist in using inefficient ways of representing language. Finally, I consider what we know about the neurobiological basis of such a deficit. There is mounting evidence that children with SLI have subtle structural anomalies affecting the language areas of the brain, which are largely genetically determined. We should not, however, conclude that the language difficulties are immutable. [source]


Cover Picture: Electrophoresis 19'2008

ELECTROPHORESIS, Issue 19 2008
Article first published online: 28 OCT 200
This issue has a dual emphasis: "APCE 2007" and "Fundamentals and Methodologies" with the aim of providing the readers of the Journal with the latest developments in the field. APCE 2007, which was held in Singapore, December 17 , 19, 2007, is the premier forum in the Asia-Pacific countries for communicating advances in capillary- and chip-based electroseparation techniques and their applications to genomics, proteomics, and chemical and biochemical analysis. The emphasis part on APCE 2007 is a "mini proceeding" that groups 7 representative research articles, which deal with microchip electrophoresis, restriction fragment length polymorphism analysis by CE, gradient MEKC, stacking and sweeping in CE, in-line pre-concentration in CE, and food and drug analysis by CE. In addition, issue 19 has a "Fast Track" article on the principles for different modes of multiple-injection CZE and provides equations that facilitate the transfer from single-injection CZE to one or more suitable modes of multiple injection CZE. [source]


Cover Picture: Electrophoresis 10/2008

ELECTROPHORESIS, Issue 10 2008
Article first published online: 21 MAY 200
Regular issues provide a wide range of research and review articles covering all aspects of electrophoresis. Here you will find cutting-edge articles on methods and theory, instrumentation, nucleic acids, CE and CEC, miniaturization and microfluidics, proteomics and two-dimensional electrophoresis. "The present issue includes 29 manuscripts subdivided into three major parts: one part is devoted to instrumental and methodological advances, and two parts are providing an insight into up-to-date applications from the fields of natural products and food analysis on the one hand and biomedical and pharmaceutical analysis on the other hand. The approaches used comprise different modes of electroseparation methods such as CZE, packed column, monolithic column and open-tubular CEC, MEKC, CIEF, CITP, different modes of ionization such as MALDI, ICP, and ESI, as well as a range of mass analyzers from simple single quadrupole MS to top of the range Q-TOF instruments, providing MS-MS and accurate mass features." [source]


Etoposide and merbarone are clastogenic and aneugenic in the mouse bone marrow micronucleus test complemented by fluorescence in situ hybridization with the mouse minor satellite DNA probe

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2003
S.M. Attia
Abstract The topoisomerase II (topo II) inhibitors etoposide (VP-16) and merbarone (MER) were investigated with the in vivo micronucleus test (MN test) combined with fluorescence in situ hybridization (FISH) using the mouse minor satellite DNA probe to discriminate MN of clastogenic and aneugenic origin. All experiments were performed with male (102/ElxC3H/El) F1 mice bred in the mouse colony of the GSF Research Center. The sample size per experimental group was five animals and 2,000 polychromatic erythrocytes (PCE) were scored per animal from coded slides in the conventional MN test. A separate set of coded slides was used for the FISH analysis. All treatments consisted of single intraperitoneal injections. Colchicine (COL, 3 mg/kg) and mitomycin (MMC, 1 mg/kg) were used as a positive control aneugen and clastogen, respectively, and these compounds produced the expected responses. A dose of 1 mg/kg VP-16 induced 3.44% MNPCE (compared to the concurrent solvent control of 0.37%, P < 0.001) and of these 39.9% (1.4% MNPCE) showed one or more fluorescent signals. MER (7.5,60 mg/kg) increased the MNPCE frequencies in a dose-dependent manner, with 15 mg/kg being the lowest positive dose. At the highest dose of 60 mg/kg of MER, a total of 4.26% MNPCE were found (compared to 0.31% in the concurrent solvent control, P < 0.001) and of these 46.2% (2.0% MNPCE) contained one or more fluorescent signals. The data demonstrate that VP-16 and MER induced both clastogenic and aneugenic events despite their different modes of topo II inhibition. Environ. Mol. Mutagen. 41:99,103, 2003. © 2003 Wiley-Liss, Inc. [source]


Cytotoxicity assessment of gliotoxin and penicillic acid in Tetrahymena pyriformis

ENVIRONMENTAL TOXICOLOGY, Issue 2 2006
C. Gräbsch
Abstract Various studies have documented the associations between mold exposure and effects on health. Mycotoxins, which occur in spores and mold fragments, can be involved in processes that have pathological effects, such as adynamia of the immune system, recurrent infections of the respiratory tract, or asthma. Using Tetrahymena pyriformis, a single-cell organism well established as a suitable model for human respiratory epithelium-cell functionalities, we investigated dose,response relationships of the mycotoxins gliotoxin and penicillic acid. Our study focused on the viability (cell count, MTT assay), energy levels (adenosine-5,-triphosphate content), energy-providing processes (MTT reduction per cell), and cell respiration (oxygen consumption). Both mycotoxins acted as cytotoxins in a dose-dependent manner. Gliotoxin had a stronger inhibitory effect (EC50 0.38 ,M) than did penicillic acid (EC50 343.19 ,M). The energy-providing processes were not inhibited or were only weakly inhibited under the influence of gliotoxin, whereas penicillic acid caused stimulation of the physiological parameters. Summarizing the results, it is clear that the two investigated mycotoxins must have different modes of action. They are not only different in the strength of their toxic effects but also in a variety of physiological aspects. In addition, T. pyriformis showed differences in its ability to overcome the negative effects of particular mycotoxin exposures. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 111,117, 2006. [source]


Altered gene expression in the brain and ovaries of zebrafish (Danio Rerio) exposed to the aromatase inhibitor fadrozole: Microarray analysis and hypothesis generation,,

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2009
Daniel L. Villeneuve
Abstract As part of a research effort examining system-wide responses of the hypothalamic-pituitary-gonadal (HPG) axis in fish to endocrine-active chemicals (EACs) with different modes of action, zebrafish (Danio rerio) were exposed to 25 or 100 ,g/L of the aromatase inhibitor fadrozole for 24, 48, or 96 h. Global transcriptional response in brain and ovarian tissue of fish exposed to 25 ,g/L of fadrozole was compared to that in control fish using a commercially available, 22,000-gene oligonucleotide microarray. Transcripts altered in brain were functionally linked to differentiation, development, DNA replication, and cell cycle. Additionally, multiple genes associated with the one-carbon pool by folate pathway (KEGG 00670) were significantly up-regulated. Transcripts altered in ovary were functionally linked to cell-cell adhesion, extracellular matrix, vasculogenesis, and development. Promoter motif analysis identified GATA-binding factor 2, Ikaros 2, alcohol dehydrogenase gene regulator 1, myoblast-determining factor, and several heat shock factors as being associated with coexpressed gene clusters that were differentially expressed following exposure to fadrozole. Based on the transcriptional changes observed, it was hypothesized that fadrozole elicits neurodegenerative stress in brain tissue and that fish cope with this stress through proliferation of radial glial cells. Additionally, it was hypothesized that changes of gene expression in the ovary of fadrozole-exposed zebrafish reflect disruption of oocyte maturation and ovulation because of impaired vitellogenesis. These hypotheses and others derived from the microarray results provide a foundation for future studies aimed at understanding responses of the HPG axis to EACs and other chemical stressors. [source]


Examining the single and interactive effects of three insecticides on amphibian metamorphosis,

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2008
Michelle D. Boone
Abstract Although aquatic communities frequently are exposed to a number of pesticides, the effects of chemical mixtures are not well understood. In two separate studies, I examined how insecticide mixtures influenced the likelihood of unpredictable, nonadditive effects on American toad (Bufo americanus) and green frog (Rana clamitans) tadpoles reared in outdoor aquatic communities. I exposed tadpoles to single or multiple insecticides at approximately half the reported median lethal concentrations using insecticides that were either acetylcholinesterase inhibitors (carbaryl or malathion) or a sodium-channel disruptor (permethrin). I found that combinations of insecticides with the same mode of action were more likely to have nonadditive effects on amphibian metamorphosis compared with those having different modes of action. Additionally, in one study, a commercial formulation of permethrin led to near-complete elimination of American toads, suggesting that this formulation could have adverse effects on aquatic communities. Many community studies exploring the ecological effects of expected environmental concentrations of pesticides have suggested that indirect effects in the food web, rather than direct effects on individual physiology, have the largest effect on amphibians. The present study indicates that direct effects of pesticides may become particularly important when insecticides with the same mode of action are present in the environment. [source]


Fluorocycloalkylated Fullerenes in the Systems C60/70,C2F4I2

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 30 2007
Anna S. Pimenova
Abstract An addition reaction of biradicals thermally generated from C2F4I2 was applied to functionalize fullerenes. This resulted in the formation of a number of C60(C2F4)n and C70(C2F4)m compounds. HPLC separation allowed the determination of the molecular structures of C60(C4F8)2 (two isomers), C60(C4F8)6, and C70(C2F4)2 and revealed that these compounds are formed by different modes of [4,+,2], [4,+,3], and [2,+,2] addition, respectively. A new synthetic approach for the preparation of a series of fluorocycloalkylated derivatives of fullerenes should be further exploited. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


METAMODELS AND PHYLOGENETIC REPLICATION: A SYSTEMATIC APPROACH TO THE EVOLUTION OF DEVELOPMENTAL PATHWAYS

EVOLUTION, Issue 11 2009
Artyom Kopp
Molecular genetic analysis of phenotypic variation has revealed many examples of evolutionary change in the developmental pathways that control plant and animal morphology. A major challenge is to integrate the information from diverse organisms and traits to understand the general patterns of developmental evolution. This integration can be facilitated by evolutionary metamodels,traits that have undergone multiple independent changes in different species and whose development is controlled by well-studied regulatory pathways. The metamodel approach provides the comparative equivalent of experimental replication, allowing us to test whether the evolution of each developmental pathway follows a consistent pattern, and whether different pathways are predisposed to different modes of evolution by their intrinsic organization. A review of several metamodels suggests that the structure of developmental pathways may bias the genetic basis of phenotypic evolution, and highlights phylogenetic replication as a value-added approach that produces deeper insights into the mechanisms of evolution than single-species analyses. [source]