bluuebunny/crossref_metadata_2025 huggingface dataset:
Superantigen- and TLR-Dependent Activation of Tonsillar B Cells after Receptor-Mediated Endocytosis
Authors: Jendholm Johan , Mörgelin Matthias , Perez Vidakovics Maria Laura A. , Carlsson Michael , Leffler Hakon , Cardell Lars-Olaf , Riesbeck Kristian
Published: April 2009

Classical B lymphocyte activation is dependent on BCR cross-linking in combination with physical interaction with Th cells. Other B cell molecules that contribute to the activation are complement, cytokine, and TLRs recognizing specific pathogen-associated molecular patterns. Moraxella (Branhamella) catarrhalis is a common Gram-negative respiratory pathogen that induces proliferation in human IgD-expressing B cells independently of T cell help. The activation is initiated by the B cell superantigen Moraxella IgD-binding protein (MID) through a nonimmune cross-linking of IgD. However, IgD cross-linking alone is not sufficient to induce proliferation. In this study, we characterized the significance of TLRs in superantigen-dependent B cell activation using whole bacteria or rMID in the presence or absence of TLR ligands. IgD cross-linking by MID sensitized B cells obtained from children with tonsillar hyperplasia for mainly TLR9, whereas TLRs 1, 2, 6, and 7 were less important. The Moraxella-induced activation was inhibited when a dominant-negative TLR9 ligand was added. Interestingly, BCR-mediated endocytosis of whole Moraxella and degradation of live bacteria in naive B cells were observed with fluorescence, confocal, and transmission electron microscopy. This unique observation proved the strong intracellular TLR9 response as well as highlighted the Ag-presenting function of B cells. In conclusion, our findings suggest an important role of TLRs in the adaptive immune response and reveal novel insights into the T cell-independent B cell activation induced by bacteria.
The Pattern Recognition Receptor CD36 Is a Chondrocyte Hypertrophy Marker Associated with Suppression of Catabolic Responses and Promotion of Repair Responses to Inflammatory Stimuli
Authors: Cecil Denise L. , Appleton C. Thomas G. , Polewski Monika D. , Mort John S. , Schmidt Ann Marie , Bendele Alison , Beier Frank , Terkeltaub Robert
Published: April 2009

Multiple inflammatory mediators in osteoarthritis (OA) cartilage, including S100/calgranulin ligands of receptor for advanced glycation end products (RAGE), promote chondrocyte hypertrophy, a differentiation state associated with matrix catabolism. In this study, we observed that RAGE knockout was not chondroprotective in instability-induced knee OA in 8-wk-old mice. Hence, we tested the hypothesis that expression of the alternative S100/calgranulin and patterning receptor CD36, identified here as a marker of growth plate chondrocyte hypertrophy, mediates chondrocyte inflammatory and differentiation responses that promote OA. In rat knee joint destabilization-induced OA, RAGE expression was initially sparse throughout cartilage but increased diffusely by 4 wk after surgery. In contrast, CD36 expression focally increased at sites of cartilage injury and colocalized with developing chondrocyte hypertrophy and aggrecan cleavage NITEGE neoepitope formation. However, CD36 transfection in normal human knee-immortalized chondrocytes (CH-8 cells) was associated with decreased capacity of S100A11 and TNF-α to induce chondrocyte hypertrophy and ADAMTS-4 and matrix metalloproteinase 13 expression. S100A11 lost the capacity to inhibit proteoglycans synthesis and gained the capacity to induce proteoglycan synthesis in CD36-transfected CH-8 cells. Moreover, S100A11 required the p38 MAPK pathway kinase MKK3 to induce NITEGE development in mouse articular cartilage explants. However, CH-8 cells transfected with CD36 demonstrated decreased S100A11-induced MKK3 and p38 phosphorylation. Therefore, RAGE and CD36 patterning receptor expression were linked with opposing effects on inflammatory, procatabolic responses to S100A11 and TNF-α in chondrocytes.
Induction of Tumor Cell Apoptosis or Necrosis by Conditional Expression of Cell Death Proteins: Analysis of Cell Death Pathways and In Vitro Immune Stimulatory Potential
Authors: Lohmann Christine , Muschaweckh Andreas , Kirschnek Susanne , Jennen Luise , Wagner Hermann , Häcker Georg
Published: April 2009

For the efficient stimulation of T cells by tumor Ag, tumor-derived material has to be presented by dendritic cells (DC). This very likely involves the uptake of dead tumor cells by DC. Cell death in tumors often occurs through apoptosis, but necrotic cell death may also be prevalent. This distinction is relevant because numerous studies have proposed that apoptotic cells have immunosuppressive effects while necrosis may be stimulatory. However, a system has been lacking that would allow the induction of apoptosis or necrosis without side effects by the death stimuli used experimentally. In this study, we present such a system and test its effects on immune cells in vitro. B16 mouse melanoma cells were generated and underwent cell death through the doxycycline-inducible induction of death proteins. In one cell line, the induction of BimS induced rapid apoptosis, in the other line the induction of the FADD death domain induced nonapoptotic/necrotic cell death. BimS-induced apoptosis was associated with the typical morphological and biochemical changes. FADD death domain induced necrosis occurred through a distinct pathway involving RIP1 and the loss of membrane integrity in the absence of apoptotic changes. Apoptotic and necrotic cells were taken up with comparable efficiency by DC. OVA expressed in cells dying by either apoptosis or necrosis was cross-presented to OT-1 T cells and induced their proliferation. These results argue that it is not the form of cell death but its circumstances that decide the question whether cell death leads to a productive T cell response.
Synthesis and Biological Activities of Novel Thiophosphoryl Oximates Containing Thiazole and 1,2,3‐Triazole Rings
Authors: ZHU Xiaofei , SHI Deqing
Published: April 2009

In order to find novel high activity and low toxicity agrochemicals, a series of novel thiophosphoryl oximates containing thiazole and 1,2,3‐triazole rings 4 were synthesized by the reactions of 1‐{1‐[(2‐chlorothiazol‐5‐ yl)methyl]‐5‐methyl‐1H‐1,2,3‐triazol‐4‐yl}ethanone oxime with various asymmetric thiophosphoryl chlorides. Their structures were confirmed by IR, 1H NMR, 31P NMR, EI‐MS and elemental analyses. The target compounds existed as E‐configuration, which was deduced by NMR analysis and by comparison with their pyridyl analog determined by X‐ray diffraction. The results of preliminary bioassay indicate that some of title compounds possess moderate insecticidal and fungicidal activities.
Ultrastructure and distribution of superficial neuromasts of blind cavefish, Phreatichthys andruzzii, juveniles
Authors: Dezfuli Bahram S. , Magosso Sara , Simoni Edi , Hills Kathleen , Berti Roberto
Published: April 2009

Transmission and scanning electron microscopy (TEM, SEM) were used to study the ultrastructure of superficial neuromasts in 15 six‐month old blind cavefish juveniles, Phreatichthys andruzzii (Cyprinidae). In five specimens examined with SEM, the number of superficial neuromasts over the fish body (480–538) was recorded. They were localized mainly on the head (362–410), including the dorsal surface, the mentomandibular region, and laterally from the mouth to the posterior edge of the operculum. Neuromasts were also present laterally on the trunk and near the caudal fin (116–140). A significantly higher number of neuromasts were present on the head compared to the trunk (t‐test, P < 0.05). Superficial neuromasts of the head and those along the trunk were similar in ultrastructure. Each neuromast comprised sensory hair cells surrounded by nonsensory support cells (mantle cells and supporting basal cells) with the whole covered by a cupula. Each hair cell was pear‐shaped, 15–21 μm high and 4–6 μm in diameter, with a single long kinocilium and several short stereocilia. Most support cells were elongated, with nuclei occupying a large portion of the cytoplasm. In the margin of the neuromast, mantle cells were particularly narrow. Both types of support cells had well‐developed Golgi apparatus and rough endoplasmic reticulum. The number of hair cells and nonsensory support cells of the anterior lateral line (head) did not differ significantly from those of the posterior lateral line (trunk) (t‐test, P > 0.05). Microsc. Res. Tech. 2009. © 2009 Wiley‐Liss, Inc.
Electron‐impact induced fragmentation of thiirene and thiophene dioxides
Authors: Vouros Paul
Published: April 2009

The electron impact mass spectra of several substituted thiirene and thiophene oxides and dioxides have been investigated using both low and high resolution mass spectrometry. The predominant fragmentation process in the spectra of the thiirene compounds is the elimination of the hetero (SO or SO2) function and formation of a substituted acetylene ion. The 5‐membered ring thiophene dioxides exhibit mainly elimination of SO rather than SO2. Plausible mechanisms leading to the formation of the principal ions are proposed on the basis of metastable transitions.
The chemistry of N‐cyanodithioimidocarbonic acid. III. An intermediate in heterocyclic synthesis
Authors: Wittenbrook Lawrence S.
Published: April 2009

The synthesis of substituted benzimidazole, benzothiazole, oxadiazole and triazine systems from dipotassium N‐cyanodithioimidocarbonate are described.
A general synthesis of s‐triazolo[1,5‐x] diazines
Authors: Tamura Yasumitsu , Kim Joong‐Hyup , Ikeda Masazumi
Published: April 2009

Treatment of 2‐aminopyrimidime, a 4‐aminopyrimidine, aminopyrazine, and 3‐aminopyridazines with O‐mesilylenesulfonylhydroxylamine gave the corresponding N‐aminodiazinium salts in high yields. These salts could be transformed into s‐triazolo[1, 5‐a] pyrimidines, s‐triazolo[1, 5‐a]‐pyrazines, s‐triazolo[1, 5‐c]pyrimidines, and s‐triazolo[1, 5‐b]pyridazines hy treatment with acylating agents.
An INDO study of the isomerization of aziridinone
Authors: Talaty Erach R. , Zandler Melvin E.
Published: April 2009

The only pathway postulated in the literature for the isomerization of aziridinone (Ia) to iminooxirane (IIIa) involves a planar, open‐chain, dipolar intermediate (IIa); however, INDO calculations suggest a possible alternative pathway in which an in‐plane bending of the oxygen atom towards the alkyl carbon atom occurs rather than a stretching of the alkyl‐nitrogen bond. INDO calculations also suggest that the unknown compound IIIa has the same degree of stability as Ia.
Synthèse de composés comportant deux hétérocycles oxygénés accoles au noyau benzénique, éthers du résorcinol
Authors: Graffe B. , Sacquet M.‐C. , Maitte P.
Published: April 2009

Nous reportons ici la préparation de nouveaux composés bishétérocycliques dérivés du résorcinol. Nous nous sommes efforcés, au cours de ce travail d'utiliser des méthodes qui conduisent à une cyclisation sélective n'amenant que l'enchaǐnement tricyclique linéaire; le précurseur est soil le résorcinol soit son éther monométhylique.

Par réaction avec le chloracétronitrile, l'acrylonitrile ou le chlorobutanoate d'éthyle, les composés intermédiairement obtenus sont cyclisés par l'acétate de sodium ou l'acide polyphosphorique; une réduction soit catalytique soit par le zinc en présence d'acide chlorhydrique conduit aux hétérocycles de base. Une seconde condensation suivie de cyclisation puis de réduction conduit au bishétérocycle attendu.
Synthese, thermolyse et photolyse de quelques cyano‐4‐amino‐5‐triazolines
Authors: Texier Fernand , Bourgois Jacques
Published: April 2009

L'addition du phénylazide à différents β aminométhacrylonitriles permet d'obtenir des triazolines stables, dont la thermolyse met en évidence la réversibilité de la cycloaddition dipolaire‐1,3. Par contre, la photolyse de ces triazolines conduit à des aminoaziridines activées, ylures d'azométhine potentiels, facilement hydrolysables. L'addition du tosylazide à ces memes dipolarophiles conduit à des produits différents, des amidines et le cyano‐1 diazoéthane.
Thienopyrimidines. VII. Reactions of the 4‐hydrazinothieno[2,3‐d]pyrimidines
Authors: Robba M. , de Sevricourt M. Cugnon , Lecomte J. M.
Published: April 2009

The cyclization reactions of the 4‐hydrazinothieno[2,3‐d]pyrimidines give s‐triazolo[1,2‐c]‐thieno[3,2‐e]pyrimidines and tetrazolo[1,5‐c]thieno[3,2‐e]pyrimidines.
Utilisation des déplacements chimiques induits par les lanthanides a la détermination de la structure de benzothiénopyridines
Authors: Gacel G. , Fournié‐Zaluski M. C. , Roques B. P.
Published: April 2009

Les déplacements chimiques induits par les lanthanides ont permis d'attribuer les spectres de RMN 1H de benzothiénopyridines et de déterminer leur site de substitution préférentiel. D'autre part, on a pu mettre en évidence l'influence de l'encombrement stérique au niveau du site de complexation, sur la position spatiale de l'ion lanthanide.
1,8‐Naphthyridines. Part I. Synthesis of some trifluoromethyl‐1,8‐naphthyridine derivatives
Authors: Eichler Eva , Rooney Clarence Stanley , Williams Haydn Windsor Richard
Published: April 2009

The synthesis of some 2‐amino‐1,8‐naphthyridine derivatives substituted in the 5‐ and/or 7‐positions with trifluoromethyl is described along with their conversions to the corresponding 1,8‐naphthyridin‐2(1H)ones. A modified procedure for oxidizing electron‐deficient heterocyclic compounds to theirN‐oxides is presented.
The reactions of 3‐Butyl‐1,2‐diphenylphosphindole with dimethyl acetylenedicarboxylate
Authors: Hughes Alan N. , Amornraksa Kitti , Phisithkul Siriporn , Reutrakul Vichai
Published: April 2009

Unlike 1,2,5‐triphenylphosphole, 3‐butyl‐1,2‐diphenylphosphindole reacts smoothly with two molecules of dimethyl acetylenedicarboxylate to give the phosphindole oxide, a yellow adduct and a colourless adduct. The case of the reaction is taken to indicate less lone pair interaction with the π‐system in phosphindoles than in phospholes. The yellow adduct is shown to be a phosphindolium cyclopentadienylide, i.e. an adduct of the phosphindole and two molecules of the ester less one oxygen atom. The colourless adduct is shown to be a 1:2:1 adduct of the phosphindole, the ester and water and has a benzodihydrophosphonin structure. Mechanisms for the formation of both adducts are proposed. Adducts of this general type were previously unknown in organophosphorus chemistry.
Pyrrolopyrimidine nucleosides. XIII. Synthesis and chemical reactivity of certain selenopyrrolo[2,3‐d]pyrimidine nucleosides
Authors: Milne George. H. , Townsend Leroy B.
Published: April 2009

5‐Cyano‐7‐(β‐D‐ribofuranosyl)pyrrolo[2,3‐d]pyrimidin‐4‐selone (1) has been prepared via a reaction of the appropriate 4‐chloro compound with sodium hydrogen selenide. Alkylation of 2 under basic conditions has provided certain 4‐substitutedseleno‐5‐cyano‐7‐(β‐D‐ribofuranosyl)‐pyrrolo[2,3‐d]pyrimidines. 5‐Cyano‐4‐methylseleno‐7‐(β‐D‐ribofuranosyl)pyrrolo[2,3‐d]pyrimidine was allowed to react with hydroxylamine and hydrazine. The products obtained and reaction course were compared to those obtained from identical reactions using the corresponding sulfur analog.
About the structure of two isomeric pyrazoloquinolines
Authors: Prime J. , Stanovnik B. , Tišler M.
Published: April 2009

Several structures are possible for the pyrazoloquinolines, formed in the Skraup synthesis from 5‐ or 6‐aminoindazole. By nmr spectroscopic examination in the presence of shift reagents it was possible to assign the correct structures for both products, i.e., the angular 1H‐pyrazolo‐[3,4‐f]quinoline (4) and 3H‐pyrazolo[4,3‐f]quinoline (2).
A cinnoline 2‐oxide from 2‐nitrosobenzophenone
Authors: Walser Armin , Zenchoff Gladys
Published: April 2009

Base catalyzed cyclization of the 2‐methylazoxybenzophenone (4B) obtained by condensation of the 2‐nitrosobenzophenone (2a) with methylhydroxylamine led to the cinnoline 2‐oxide (7) which is the major product of the peracid oxidation of the corresponding cinnoline (5).
Role of monocyte chemoattractant protein‐1 (MCP‐1/CCL2) in migration of neural progenitor cells toward glial tumors
Authors: Magge Suresh N. , Malik Saafan Z. , Royo Nicolas C. , Chen H. Isaac , Yu LiYa , Snyder Evan Y. , O'Rourke Donald M. , Watson Deborah J.
Published: April 2009

Neural progenitor cells (NPCs) have been investigated as potential vehicles for brain tumor therapy because they have been shown to migrate toward central nervous system gliomas and can be genetically engineered to deliver cytotoxic agents to tumors. The mechanisms that regulate migration of NPCs to tumors are not fully understood. By means of microarray analysis, polymerase chain reaction, enzyme‐linked immunosorbent assay, and immunohistochemistry, we found that monocyte chemoattractant protein‐1 (MCP‐1/CCL‐2) was expressed in experimental brain tumor cells in vivo and in vitro. CCR2, the receptor for MCP‐1, was expressed on C17.2 NPCs. We used a modified Boyden chamber assay and found increased migration of NPCs in vitro in response to MCP‐1. By means of an in vivo model for NPC migration, we found evidence of NPC migration toward areas of MCP‐1 infusion in rat brains. An understanding of NPC migration mechanisms may be used to enhance delivery of cytotoxic agents to brain tumor cells. © 2009 Wiley‐Liss, Inc.
Higher immunoglobulin production in conjugated linoleic acid-supplemented rats during gestation and suckling
Authors: Ramírez-Santana Carolina , Pérez-Cano Francisco J. , Castellote Cristina , Castell Margarida , Rivero Montserrat , Rodríguez-Palmero María , Franch Àngels
Published: April 2009

Conjugated linoleic acid (CLA) has been reported to exert beneficial physiological effects on body composition and the immune system. However, little information is available on the influence of CLA on immune function during early life periods. The present study evaluates the effect of feeding an 80:20 mixture of cis-9, trans-11- and trans-10, cis-12-CLA isomers during gestation and suckling on the systemic immune response of weaned Wistar rats. Pups received dietary CLA from dams through the placental barrier and during suckling by breast milk (group A) or by oral administration (group B). Pups from group C only received CLA during suckling by oral administration. Group D constituted the reference group. Milk from dams fed the CLA diet had a high content of CLA and higher IgA and IgG concentrations than rats fed the standard diet. The plasma of pups from groups A, B and C showed six, twelve and nine times higher content of the cis-9, trans-11-CLA isomer than that of the group D pups. Rats from group A exhibited higher serum IgG concentrations than rats from the rest of the groups (22·14 (sem 2·14) v. about 5 mg/ml; P < 0·05), whereas rats from groups A and B showed approximately 2-fold higher splenocyte IgM production than rats from groups C and D. However, CLA supplementation did not influence significantly the splenocyte proliferative response or cytokine secretion. Supplementation during gestation and suckling with an 80:20 cis-9, trans-11–trans-10, cis-12 CLA mix enhances the production of the main in vivo and in vitro Ig isotypes in Wistar rats.
Unraveling the Financial Crisis of 2008
Authors: Comiskey Michael , Madhogarhia Pawan
Published: April 2009

In the fall of 2008, the world economy experienced a
“once-in-a-century credit tsunami” (Greenspan 2008, 1). Centered in the market for homes
and mortgages, the mechanisms that unleashed this financial tidal
wave are many and complex. Indeed, an inadequate grasp of modern
finance on the part of “the most sophisticated investors” and
regulators “in the world” was itself a contributing factor
(Greenspan 2008, 3).
Geomagnetic signatures of auroral substorms preceded by pseudobreakups
Authors: Kullen A. , Ohtani S. , Karlsson T.
Published: April 2009

The evolution of ten growth‐phase pseudobreakups and subsequent substorms, identified in Northern Hemisphere Polar UV images during winter 1998–1999, are compared to the AE index, the unified PC indices, and GOES B field data. Comparing substorm onset (auroral breakup) with GOES data and AE and PC indices, it is found that an exact onset determination from these parameters is in most cases not possible. The three weakest substorms leave no clear signatures in the auxiliary parameters. For the other events, the AE increase appears with a time delay of 5–15 min after onset. The PC indices increase, as expected, before the AE index. The time span between PC increase and onset varies widely (−26 to 5 min). A tail dipolarization is seen in GOES data with a time delay of 2–31 min after onset. The dipolarization delay at geosynchronous orbit appears because of the GOES displacement from the tail onset region. Using the mapped GOES distance from the auroral breakup region as an estimate of GOES displacement from the breakup source region, we find that the tail dipolarization region expands in average with an azimuthal speed of 0.22 MLT min−1 and an equatorward speed of 0.09° min−1. Pseudobreakups leave hardly any signature in AE or PC index data except in the four strongest substorm cases. In these cases, a bump appears in the PC indices during the pseudobreakup. A bump in geosynchronous B field data is found only in those two cases where GOES is located very close to the pseudobreakup tail source region.
Predicting Climate Change: Lessons From Reductionism, Emergence, and the Past
Authors: Harrison Stephan , Stainforth Dave
Published: April 2009

Climate and Earth system models are the only tools used to make predictions of future climate change. Such predictions are subject to considerable uncertainties, and understanding these uncertainties has clear and important policy implications. This Forum highlights the concepts of reductionism and emergence, and past climate variability, to illuminate some of the uncertainties faced by those wishing to model the future evolution of global climate.

General circulation models (GCMs) of the atmosphere‐ocean system are scientists' principal tools for providing information about future climate. GCMs consequently have considerable influence on climate change–related policy questions. Over the past decade, there have been significant attempts, mainly by statisticians and mathematicians, to explore the uncertainties in model simulations of possible futures, accompanied by growing debate about the interpretation of these simulations as aids in societal decisions. In this Forum, we discuss atmosphere‐ocean GCMs in the context of reductionist and emergent approaches to scientific study.
Dielectric, piezoelectric, and electromechanical phenomena in (K0.5Na0.5)NbO3–LiNbO3–BiFeO3–SrTiO3 ceramics
Authors: Li Enzhu , Suzuki Ryo , Hoshina Takuya , Takeda Hiroaki , Tsurumi Takaaki
Published: April 2009

The effect of the substitutions of BiFeO3 (BF) and SrTiO3 (ST) to (Na0.5K0.5)NbO3–LiNbO3 (KNN-LN) ceramics was studied as a candidate of lead-free piezoceramics. The piezoelectric property is enhanced near the phase transition composition caused by the distortion of crystal lattice by Li+ and also the strong ferroelectric nature of BF. The ST was found to be effective in improving the temperature dependence of the KNN ceramics. Small amount of ST also promoted the incorporation of LN and BF into the crystal lattice, and enhanced the piezoelectric performance furthermore. The 94.5(Na0.5K0.5)NbO3-4.5LiNbO3-0.5SrTiO3-0.5BiFeO3 ceramics showed excellent piezoelectric properties of d15=231 pC/N, d33=155 pC/N, and d31=70 pC/N.
Methods for improving simulations of biological systems: systemic computation and fractal proteins
Authors: Bentley Peter J.
Published: April 2009

Modelling and simulation are becoming essential for new fields such as synthetic biology. Perhaps the most important aspect of modelling is to follow a clear design methodology that will help to highlight unwanted deficiencies. The use of tools designed to aid the modelling process can be of benefit in many situations. In this paper, the modelling approach called systemic computation (SC) is introduced. SC is an interaction-based language, which enables individual-based expression and modelling of biological systems, and the interactions between them. SC permits a precise description of a hypothetical mechanism to be written using an intuitive graph-based or a calculus-based notation. The same description can then be directly run as a simulation, merging the hypothetical mechanism and the simulation into the same entity. However, even when using well-designed modelling tools to produce good models, the best model is not always the most accurate one. Frequently, computational constraints or lack of data make it infeasible to model an aspect of biology. Simplification may provide one way forward, but with inevitable consequences of decreased accuracy. Instead of attempting to replace an element with a simpler approximation, it is sometimes possible to substitute the element with a different but functionally similar component. In the second part of this paper, this modelling approach is described and its advantages are summarized using an exemplar: the fractal protein model. Finally, the paper ends with a discussion of good biological modelling practice by presenting lessons learned from the use of SC and the fractal protein model.
Habitat-dependent and -independent plastic responses to social environment in the nine-spined stickleback (Pungitius pungitius) brain
Authors: Gonda Abigél , Herczeg Gábor , Merilä Juha
Published: April 2009

The influence of environmental complexity on brain development has been demonstrated in a number of taxa, but the potential influence of social environment on neural architecture remains largely unexplored. We investigated experimentally the influence of social environment on the development of different brain parts in geographically and genetically isolated and ecologically divergent populations of nine-spined sticklebacks (Pungitius pungitius). Fish from two marine and two pond populations were reared in the laboratory from eggs to adulthood either individually or in groups. Group-reared pond fish developed relatively smaller brains than those reared individually, but no such difference was found in marine fish. Group-reared fish from both pond and marine populations developed larger tecta optica and smaller bulbi olfactorii than individually reared fish. The fact that the social environment effect on brain size differed between marine and pond origin fish is in agreement with the previous research, showing that pond fish pay a high developmental cost from grouping while marine fish do not. Our results demonstrate that social environment has strong effects on the development of the stickleback brain, and on the brain's sensory neural centres in particular. The potential adaptive significance of the observed brain-size plasticity is discussed.
Two fungal symbioses collide: endophytic fungi are not welcome in leaf-cutting ant gardens
Authors: Van Bael Sunshine A. , Fernández-Marín Hermógenes , Valencia Mariana C. , Rojas Enith I. , Wcislo William T. , Herre Edward A.
Published: April 2009

Interactions among the component members of different symbioses are not well studied. For example, leaf-cutting ants maintain an obligate symbiosis with their fungal garden, while the leaf material they provide to their garden is usually filled with endophytic fungi. The ants and their cultivar may interact with hundreds of endophytic fungal species, yet little is known about these interactions. Experimental manipulations showed that (i) ants spend more time cutting leaves from a tropical vine,
Merremia umbellata
, with high versus low endophyte densities, (ii) ants reduce the amount of endophytic fungi in leaves before planting them in their gardens, (iii) the ants' fungal cultivar inhibits the growth of most endophytes tested. Moreover, the inhibition by the ants' cultivar was relatively greater for more rapidly growing endophyte strains that could potentially out-compete or overtake the garden. Our results suggest that endophytes are not welcome in the garden, and that the ants and their cultivar combine ant hygiene behaviour with fungal inhibition to reduce endophyte activity in the nest.
RELATIONSHIP BETWEEN WATER ACTIVITY, DEFORMATION SPEED, AND CRISPNESS CHARACTERIZATION
Authors: CASTRO‐PRADA EVA M. , PRIMO‐MARTÍN CRISTINA , MEINDERS MARCEL B.J. , HAMER ROB J. , VAN VLIET TON
Published: April 2009

Very little is known on the rate dependency of the fracture behavior of crispy products as a function of water activity (Aw). Therefore, the effect of deformation speed on instrumental and sensory crispness was studied as a function of Aw. Deformation speed clearly affects the transition Aw range from crispy to non‐crispy. At low deformation speed, the critical Aw was 0.40 ± 0.02 and at high deformation speed between 0.5 and 0.6. The transition was completed at an Aw = 0.56 ± 0.10 and 0.74 ± 0.00 for the low and high speed, respectively. The transition of sensory crispness at regular biting speed started at Aw = 0.48 and was completed at Aw = 0.75. The deformation speed effect is assumed to be caused by the viscoelastic nature of the material in the transition region causing it to behave locally relatively more viscous at low deformation speed and relatively more elastic at high deformation speed. This behavior depends on the plasticizer content, thus, Aw. For the product used in this study, the instrumental deformation speed that best correlate to sensory data is 10 to 40 mm/s. Sensory tests show that crispy attributes are perceived more intense when biting at higher speed.

PRACTICAL APPLICATIONS

A good characterization of the water activity (Aw) range over which crispness of a food product is lost is of great practical importance. The present study describes the effect of deformation speed and Aw on crispness characteristics as determined by instrumental and sensory measurements. Crispness characteristics were found to depend not only on Aw but also on deformation speed. The Aw at which the crispy material started to lose it crispness started at lower values of Aw for the low deformation speed. Instrumental data should follow a similar trend as sensory crispness as function of Aw. At high deformation speed, instrumental sound data were more closely related to loss of crispness than force data, mainly caused by problems in the force registration. To get a good correlation of sensory and instrumental data, a correct deformation speed should be selected for this purpose. Sensory tests at different biting/chewing speed were done. Crispness attributes were scored lower when Aw was higher, as well as when decreasing the biting/chewing speed.
Anther wall formation, microsporogenesis and male gametogenesis of four closely related species in Astereae (Asteraceae): description, comparison and systematic implications
Authors: Ao Chengqi , Wang Lihua , Liang Li , Wang Xiaofeng
Published: April 2009

The embryological features of microsporangiate wall formation, microsporogenesis and male gametogenesis in Aster subulatus, Kalimeris indica, Heteropappus arenarius and Erigeron annuus are described for the first time. Although external morphology might suggest that these four species differ from each another, we found no distinctly different embryological features. They all share similar characteristics, such as a tetrasporangiate anther, coexisting amoeboid and glandular tapeta, simultaneous cytokinesis (except for 12% occurrence of successive cytokinesis in E. annuus), 3‐celled mature pollen grains and endothecium of anther wall that does not develop fibrous thickenings. Based on the embryological data, we suggest that Kalimeris and Heteropappus may be included within Aster, and that Erigeron is closely related to Aster sensu lato.
Incorporation of DNA networks into microelectrode structures
Authors: Erler Christiane , Mertig Michael
Published: April 2009

Massively parallel, bottom-up controlled incorporation of DNA molecules into microfabricated interdigital gold contact arrays is reported. The specific attachment of the ends of the DNA molecules to the metal contacts is provided via thiol functional groups obtained by conjugation of the sticky ends of the DNA duplexes with thiol modified nucleotides. Directed flow in an open flow cell has been used to accomplish stretching of single-tethered, coiled duplexes into a linear “wirelike” conformation. Simultaneously, the free molecule end is forced to move towards the adjacent contact and can anchor there resulting into DNA-based interconnects between neighboring contact fingers. The used experimental setup allows the application of hydrodynamic flow in user-defined areas of the integrated electrode structure with a maximum degree of flexibility concerning both flow profile and direction. The developed method for the formation of interconnects is robust, shows a high yield, and is highly specific.
Photoluminescence variation in dot-in-a-well structures with different InAs quantum dot densities
Authors: Torchynska T. V. , Velazquez Lozada E. , Casas Espinola J. L.
Published: April 2009

Photoluminescence (PL) and its temperature dependence have been investigated in InAs quantum dots (QDs) embedded in In0.15Ga0.85As∕GaAs quantum wells (QWs). The QD density varied from 1.1×1011 down to 1.3×1010cm−2 with an increase in QD growth temperature. Three stages have been revealed in the thermal decay of the PL intensity in InAs QDs. A variety of activation energies of PL thermal decay are discussed. Numerical simulations of experimental PL thermal decay curves give possibility to analyze the area of localization of nonradiative defects in InGaAs∕GaAs QW structures with different InAs QD densities.
Field-electron emission from flexible carbon nanotube array cathodes
Authors: Hong Nguyen Tuan , Yong Kim Sang , Koh Ken Ha , Lee Soonil , Tam Ngo Thi Thanh , Minh Phan Ngoc , Khoi Phan Hong
Published: April 2009

The authors report two approaches to fabricate flexible cold cathodes having vertically aligned carbon nanotubes (VACNTs) as active electron-emitting material. In the first approach, VACNT arrays were removed from substrates, transferred to flexible metal foils or plastic films, and secured by conductive epoxy. In the other approach, polydimethylsiloxane (PDMS) was used as a supporting matrix to fabricate more sturdy freestanding flexible cathodes. Controlled infiltration of PDMS to keep the top surfaces of VACNT columns from being buried underneath PDMS was the key of this approach. Both of these methods allowed fabrication of flexible cold cathode, and preliminary test results of fabricated flexible cold cathodes showed good field-emission characteristics.
Dry etching of GaAs in high pressure, capacitively coupled BCl3∕N2 plasmas
Authors: Lee J. W. , Kim J. K. , Lee J. H. , Joo Y. W. , Park Y. H. , Noh H. S. , Pearton S. J.
Published: April 2009

The authors found high etch rates (∼0.4μmmin−1) for GaAs in a capacitively coupled plasma (CCP) system using BCl3∕N2 discharges even at an operating pressure of 150mTorr, which allows the use of simple mechanical pumps. There was a catalytic effect of the N2 gas in BCl3∕N2 plasmas during the CCP etching. Optical emission spectroscopy data show an increased neutral atomic chlorine, and positive ion density is the cause of the increased GaAs etch rate with N2 addition to the BCl3.
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high-electron mobility transistor with In0.1Ga0.9As∕In0.22Ga0.78As∕In0.1Ga0.9As channel grown by metal-organic chemical vapor deposition
Authors: Lin Yu-Shyan , Chen Bo-Yuan
Published: April 2009

A composite-channel high-electron mobility transistor (HEMT) on GaAs substrate is designed and fabricated, using the following methodology to improve device performance: (1) an AlGaAs buffer layer, (2) an AlGaAs∕GaAs superlattice layer, and (3) an In0.1Ga0.9As∕In0.22Ga0.78As∕In0.1Ga0.9As composite channel. For comparison, a control HEMT without the composite channel is fabricated in parallel (whose channel comprises only a 125-Å-thick In0.22Ga0.78As layer). These two devices are grown by metal-organic chemical vapor deposition. The peak extrinsic transconductance (gm,ext) of the control HEMT with a gate length of 1μm is 160mS∕mm, while the peak gm,ext of the composite-channel HEMT of the identical gate length is measured to be 186mS∕mm. The on-state breakdown voltage of the composite-channel HEMT is as great as 9.7V, which represents an improvement of 1.4V over the control HEMT. The control HEMT exhibits a current gain cutoff frequency (fT) of 12.5GHz and a maximum frequency of oscillation (fmax) of 31.5GHz, while the composite-channel HEMT exhibits an fT of 16.9GHz and an fmax of 37.4GHz. Experimental data reveal that the composite-channel structure provides improved gate-to-source voltage swing, improved saturation current density, enhanced fT, enhanced fmax, and enhanced breakdown voltage without compromising electron mobility. The composite-channel HEMT is thus far superior to the control HEMT and is highly promising for use in high-frequency applications.
Indium oxides by reactive ion beam assisted evaporation: From material study to device application
Authors: Wang Kai , Vygranenko Yuriy , Chaji Reza , Nathan Arokia
Published: April 2009

Indium oxides were deposited by reactive ion beam assisted e-beam evaporation at room temperature. A material study was conducted through a variety of material characterization including crystal structure, electrical properties, optical properties, and chemical composition, along with an investigation of material properties as a function of primary deposition parameters such as ion flux and deposition rate. Implementing the developed semiconducting indium oxide as a channel material, the authors further demonstrated high-performance indium oxide thin-film transistors (TFTs) with conventional silicon dioxide gate dielectric derived by plasma-enhanced chemical vapor deposition (PECVD). The n-channel TFT has a threshold voltage of ∼2.0 V, a field-effect mobility of 33 cm2/V s at a gate bias of 20 V, an ON/OFF current ratio of 108, and a subthreshold slope of 2.0 V/decade. The stability study displays a small threshold voltage shift of ∼0.6 V under a 60 h constant current stress condition. The TFT reported here has one of the best performance characteristics in terms of field-effect mobility, ON/OFF current ratio, OFF current and device stability, using conventional and large-area foundry-compatible PECVD gate dielectrics. The device performance coupled with PECVD dielectrics makes ion beam assisted e-beam evaporation derived indium oxide TFT a promising candidate for active matrix flat-panel displays.
Improvement of scanning probe microscopy local oxidation nanolithography
Authors: Nishimura Shinya , Toyofuku Takashi , Miyashita Kazuya , Takemura Yasushi , Shirakashi Jun-ichi
Published: April 2009

In order to investigate the factors that control the growth of Si local oxide, the authors have a comparative study between tapping and contact mode scanning probe microscopy (SPM) local oxidation experiments using the same SPM tip. The authors fabricated Si oxide wires with an average full width at half maximum (FWHM) of 11.0 nm in tapping mode and 54.8 nm in contact mode under the same oxidation conditions. The standard deviations of the FWHM were 2.1 and 12.2 nm in tapping and contact mode experiments, respectively. Furthermore, the authors quantitatively explained the size of the oxide controlled with tapping mode local oxidation using a model based on the oxidation ratio and the rate constant of the oxidation reaction. The oxidation ratio was estimated to be approximately 10% in tapping mode oxidation, which contributes to the 10 nm scale resolution of the oxide. Moreover, the rate constants in the tapping mode local oxidation reaction were larger than those of the contact mode oxidation. This indicates that local oxidation reaction controlled with tapping mode operation is enhanced and results in the stable oxidation, since space charges accumulated in the oxide are easily neutralized by the modulation of the electric field strength. The results imply the use of tapping mode operation for performing controllable local oxidation nanolithography.
Simple fabrication of a gated field-electron emitter with a vertical thin film formed by ion-beam irradiation
Authors: Yoshida T. , Nagao M. , Baba A. , Asano T. , Kanemaru S.
Published: April 2009

The ion-induced-bending (IIB) phenomenon was applied for fabricating a field-emitter array (FEA). The IIB method can form a vertical-thin-film (VTF) structure with micron-order height and a high aspect ratio from a thin film. Accordingly, it only needs small quantities of material and uses no specialized equipment. As a result of the optimization of the IIB phenomenon, the apex radius of the VTF was decreased by decreasing the film thickness. The material dependence of the IIB method was investigated, and the authors found that the molybdenum film gives the largest bending angle of the three refractory metals tested. An emission current of 10μA from the Mo-VTF emitter with 1000 tips was obtained at relatively low extraction voltage. Then thus conclude that IIB is a very promising method for fabricating a FEA.
Deposition of tungsten oxynitride nanowires through simple evaporation and subsequent annealing
Authors: Jeon Seongho , Kim Hyeyoung , Yong Kijung
Published: April 2009

A high density of tungsten oxynitride nanowires was synthesized by ammonia annealing of WO3 nanowires, which were grown on a tungsten substrate by thermal evaporation of WO3 powder. The morphology of WO3 nanowires was not changed upon ammonia annealing at 650°C, although the color of the sample changed drastically. X-ray diffraction and transmission electron microscopy analyses showed that the structure of the ammonia annealed nanowires matched well, with a cubic oxynitride, with the structure of W0.62(N0.62O0.38). The x-ray photoelectron spectroscopy and x-ray spectroscopy also confirmed the formation of the tungsten oxynitride nanowires. Field emission measurements showed a low turn-on field of 4.45V∕μm for the WNxOy nanowires, indicating that they can be used as potential field emitters.
Reduction effect of line edge roughness on time-dependent dielectric breakdown lifetime of Cu/low-k interconnects by using CF3I etching
Authors: Soda Eiichi , Oda Noriaki , Ito Sanae , Kondo Seiichi , Saito Shuichi , Samukawa Seiji
Published: April 2009

The authors investigated the etching of grooves in low-k in Cu technology. Correlation between the line edge roughness (LER) and the time-dependent dielectric breakdown (TDDB) reliability for 100nm pitch Cu interconnects was investigated. They controlled LER by using various gases to etch multilayer photoresist. CF3I gas was found to reduce LER better than conventional gases such as CF4 and CHF3 because CF3I has higher etching selectivity of photoresist against spin-on glass film. The LER did not affect measures of electrical performance such as wiring resistance, capacitance, and leakage current, but did affect TDDB lifetime because, according to their simulation, the electric field was strongly enhanced at curvatures in the interconnects. The maximum electric field (Emax) was also determined to evaluate the effect of LER on TDDB lifetime. All their results show that CF3I etching is promising for creating reliable Cu interconnects with smaller pitches.
Effectiveness of pain relief in labour: survey of 1000 mothers
Authors: Morgan Barbara , Bulpitt C J , Clifton P , Lewis P J
Published: April 2009

The amount of pain that had been experienced by 1000 women during vaginal delivery of a live child was determined by interview within 48 hours of delivery. Patients had been offered a choice of analgesia, and 536 had received epidural analgesia: pain relief was greatest in this group, just over half having had a painless labour. The duration of pain was also reduced by a third in this group even though patients who had received an epidural block had tended to have longer labour and an incidence of assisted delivery of 51% compared with 6% in the remainder. Seventy-two per cent of the patients receiving an epidural had had as much pain as they had expected. A similar proportion (70%) was reported with simpler analgesic methods, suggesting that women may expect a certain amount of pain in labour and request further analgesic treatment when this is exceeded.
Antenatal Sonographic Diagnosis of Pharyngeal Teratoma: Our Experience of a Rare Case with Review of the Literature
Authors: Varras M. , Akrivis Ch. , Plis Ch. , Tsoukalos G.
Published: April 2009

Background. Teratomas are the most common tumors. They are usually localized in the sacrococcygeal area, while the pharyngeal localization is very rare. The number of cases of stomatopharyngeal teratomas detected prenatally via sonography is very small.Case Report. We present the case of a 24-year-old primipara at 18 weeks' gestation, that at the routine ultrasound scan, the fetus was found with an echogenic mass, filling the stomatopharyngeal cavity and protruding from the mouth. Other abnormalities were not found. Termination of pregnancy was achieved using misoprostol. A female stillborn fetus with a weight of 250 g and length of 25.5 cm was delivered. The postmortem and pathologic examination confirmed the diagnosis.Conclusion. Pharyngeal teratomas can be diagnosed with the use of ultrasounds in utero facilitating parents' counseling in early time.
Stroke-Associated Infection Is an Independent Risk Factor for Poor Outcome after Acute Ischemic Stroke: Data from the Netherlands Stroke Survey
Authors: Vermeij Frederique H. , Scholte op Reimer Wilma J.M. , de Man Peter , van Oostenbrugge Robert J. , Franke Cees L. , de Jong Gosse , de Kort Paul L.M. , Dippel Diederik W.J.
Published: April 2009

Background: Infections are a common and serious threat to patients with acute ischemic stroke. The aim of this study was to assess the effect of infection on mortality and functional outcome at discharge and at 1 year. Methods: From a consecutive cohort study in 11 centers, the Netherlands Stroke Survey, we selected 521 patients with ischemic stroke admitted to hospital within 48 h of onset. Stroke-associated infection was defined as infection occurring within 7 days after admission. Poor outcome (modified Rankin score >2) was recorded at discharge and at 1 year. Results: Stroke-associated infection occurred in 78 patients (15%); 39 of these (7.5%) had pneumonia and 23 (4.4%) had urinary tract infection. Overall, 276 patients (53%) had a poor outcome at 1 year. Poor outcome was recorded in 69 patients with stroke-associated infection (88%), and 37 of the 78 patients with stroke-associated infection (47%) had died at 1 year. After adjustment for confounders, stroke-associated infection was associated with poor outcome at discharge [odds ratio (OR) 2.6, 95% confidence interval (CI) 1.0–6.7] and at 1 year (OR 3.8, 95% CI 1.8–8.9). Pneumonia had a stronger association with poor outcome at 1 year (OR 10, 95% CI 2.2–46). Conclusions: This study suggests that stroke-associated infection, in particular pneumonia, is independently associated with poor functional outcome after ischemic stroke.
Endoplasmic Reticulum Stress in the Kidney as a Novel Mediator of Kidney Injury
Authors: Inagi Reiko
Published: April 2009

The endoplasmic reticulum (ER) plays an important role in the maintenance of protein homeostasis through its control of the concentration, conformation, folding, and trafficking of client proteins. Disturbances such as hypoxia, glucose depletion, and oxidative stress may lead to ER dysfunction, which can induce ER stress and the subsequent unfolded protein response (UPR). The UPR initially serves as an adaptive response, but will also induce apoptosis in cells under severe or prolonged ER stress. Oxidative stress and inflammation are compounded by ER stress via the UPR, suggesting the potential pathophysiological significance of this response across a wide range of diseases. Accumulating evidence indicates that ER stress contributes to glomerular and tubular damage in patients with acute and chronic kidney disease. In glomeruli, podocyte or mesangial dysfunction tends to induce the adaptive UPR, which involves ER chaperone expression and the attenuation of protein translation, to maintain ER homeostasis and ensure cell survival. In tubules, apoptosis resulting from epithelial cell damage is caused, at least in part, by the proapoptotic UPR. These findings emphasize the possibility of the development of novel renoprotective drugs which target ER stress.