bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective expression ofKrasG12Din granulosa cells of the mouse ovary causes defects in follicle development and ovulation
Authors: Fan Heng-Yu , Shimada Masayuki , Liu Zhilin , Cahill Nicola , Noma Noritaka , Wu Yun , Gossen Jan , Richards JoAnne S.
Published: May 2008

Activation of the RAS family of small G-proteins is essential for follicle stimulating hormone-induced signaling events and the regulation of target genes in cultured granulosa cells. To analyze the functions of RAS protein in granulosa cells during ovarian follicular development in vivo, we generated conditional knock-in mouse models in which the granulosa cells express a constitutively active KrasG12D. The KrasG12D mutant mice were subfertile and exhibited signs of premature ovarian failure. The mutant ovaries contained numerous abnormal follicle-like structures that were devoid of mitotic and apoptotic cells and cells expressing granulosa cell-specific marker genes. Follicles that proceeded to the antral stage failed to ovulate and expressed reduced levels of ovulation-related genes. The human chorionic gonadotropin-stimulated phosphorylation of ERK1/2 was markedly reduced in mutant cells. Reduced ERK1/2 phosphorylation was due, in part, to increased expression of MKP3, an ERK1/2-specific phosphatase. By contrast, elevated levels of phospho-AKT were evident in granulosa cells of immature KrasG12D mice, even in the absence of hormone treatments, and were associated with the progressive decline of FOXO1 in the abnormal follicle-like structures. Thus, inappropriate activation of KRAS in granulosa cells blocks the granulosa cell differentiation pathway, leading to the persistence of abnormal non-mitotic,non-apoptotic cells rather than tumorigenic cells. Moreover, those follicles that reach the antral stage exhibit impaired responses to hormones, leading to ovulation failure. Transient but not sustained activation of RAS in granulosa cells is therefore crucial for directing normal follicle development and initiating the ovulation process.
Plectin 1 links intermediate filaments to costameric sarcolemma through β-synemin, α-dystrobrevin and actin
Authors: Hijikata Takao , Nakamura Akio , Isokawa Keitaro , Imamura Michihiro , Yuasa Katsutoshi , Ishikawa Ryoki , Kohama Kazuhiro , Takeda Shinichi , Yorifuji Hiroshi
Published: May 2008

In skeletal muscles, the sarcolemma is possibly stabilized and protected against contraction-imposed stress by intermediate filaments (IFs) tethered to costameric sarcolemma. Although there is emerging evidence that plectin links IFs to costameres through dystrophin-glycoprotein complexes (DGC), the molecular organization from plectin to costameres still remains unclear. Here, we show that plectin 1, a plectin isoform expressed in skeletal muscle, can interact with β-synemin, actin and a DGC component, α-dystrobrevin, in vitro. Ultrastructurally, β-synemin molecules appear to be incorporated into costameric dense plaques, where they seem to serve as actin-associated proteins rather than IF proteins. In fact, they can bind actin and α-dystrobrevin in vitro. Moreover, in vivo immunoprecipitation analyses demonstrated that β-synemin- and plectin-immune complexes from lysates of muscle light microsomes contained α-dystrobrevin, dystrophin, nonmuscle actin, metavinculin, plectin and β-synemin. These findings suggest a model in which plectin 1 interacts with DGC and integrin complexes directly, or indirectly through nonmuscle actin and β-synemin within costameres. The DGC and integrin complexes would cooperate to stabilize and fortify the sarcolemma by linking the basement membrane to IFs through plectin 1, β-synemin and actin. Besides, the two complexes, together with plectin and IFs, might have their own functions as platforms for distinct signal transduction.
Involvement of the nectin-afadin complex in PDGF-induced cell survival
Authors: Kanzaki Noriyuki , Ogita Hisakazu , Komura Hitomi , Ozaki Misa , Sakamoto Yasuhisa , Majima Takashi , Ijuin Takeshi , Takenawa Tadaomi , Takai Yoshimi
Published: May 2008

The nectin-afadin complex is involved in the formation of cell-cell junctions, such as adherens junctions (AJs) and tight junctions (TJs). Nectins are Ca2+-independent immunoglobulin-like cell-cell adhesion molecules, whereas afadin is an intracellular nectin-binding protein that connects nectins to the cadherin-catenin system at AJs and to the claudin–zona-occludens (ZO) protein system at TJs. Afadin–/– mice show embryonic lethality, resulting from impaired migration and improper differentiation of cells due to disorganization of cell-cell junctions during gastrulation. However, it remains to be elucidated whether disruption of afadin affects apoptosis. In the present study, we first found that embryoid bodies derived from afadin-knockout embryonic stem (ES) cells contained many more apoptotic cells than those derived from wild-type ES cells. We also revealed that apoptosis induced by serum starvation or Fas-ligand stimulation was increased in cultured NIH3T3 cells when afadin or nectin-3 was knocked down. The nectin-afadin complex was involved in the platelet-derived growth factor (PDGF)-induced activation of phosphatidylinositol 3-kinase (PI3K)-Akt signaling for cell survival. This complex was associated with PDGF receptor on the plasma membrane at cell-cell adhesion sites. Thus, the nectin-afadin complex is involved in PDGF-induced cell survival, at least through the PI3K-Akt signaling pathway.
p190B RhoGAP regulates endothelial-cell-associated proteolysis through MT1-MMP and MMP2
Authors: Guegan Fabien , Tatin Florence , Leste-Lasserre Thierry , Drutel Guillaume , Genot Elisabeth , Moreau Violaine
Published: May 2008

The two isoforms of p190 RhoGAP (p190A and p190B) are important regulators of RhoGTPase activity in mammalian cells. Both proteins are ubiquitously expressed, are involved in the same signalling pathways and interact with the same identified binding partners. In search of isoform functional specificity, we knocked down the expression of each p190 protein using siRNA and examined the resulting phenotypic changes in human umbilical vein endothelial cells (HUVECs). We provide evidence that p190B plays a crucial role in the regulation of MT1-MMP expression and cell-surface presentation, as well as subsequent MMP2 activation. p190B is involved in both local extracellular matrix degradation at podosomes and endothelial cell assembly into tube-like structures in Matrigel. In addition, whereas p190B knockdown does not affect podosome formation, p190A knockdown increases the number of cells showing podosome structures in HUVECs. We conclude that the two p190 RhoGAP isoforms play distinct roles in endothelial cells. In addition, our data reveal an unsuspected role for p190B in the expression of the two collaborative proteases MT1-MMP and MMP2, thereby affecting matrix remodelling and angiogenesis.
Nuclear pore complex proteins mark the implantation window in human endometrium
Authors: Guffanti Elisa , Kittur Nupur , Brodt Z. Nilly , Polotsky Alex J. , Kuokkanen Satu M. , Heller Debra S. , Young Steven L. , Santoro Nanette , Meier U. Thomas
Published: May 2008

Nucleolar channel systems (NCSs) are membranous organelles appearing transiently in the epithelial cell nuclei of postovulatory human endometrium. Their characterization and use as markers for a healthy receptive endometrium have been limited because they are only identifiable by electron microscopy. Here we describe the light microscopic detection of NCSs using immunofluorescence. Specifically, the monoclonal nuclear pore complex antibody 414 shows that NCSs are present in about half of all human endometrial epithelial cells but not in any other cell type, tissue or species. Most nuclei contain only a single NCS of uniform 1 μm diameter indicating a tightly controlled organelle. The composition of NCSs is as unique as their structure; they contain only a subset each of the proteins of nuclear pore complexes, inner nuclear membrane, nuclear lamina and endoplasmic reticulum. Validation of our robust NCS detection method on 95 endometrial biopsies defines a 6-day window, days 19-24 (±1) of an idealized 28 day cycle, wherein NCSs occur. Therefore, NCSs precede and overlap with the implantation window and serve as potential markers of uterine receptivity. The immunodetection assay, combined with the hitherto underappreciated prevalence of NCSs, now enables simple screening and further molecular and functional dissection.
Herpes simplex virus induces extensive modification and dynamic relocalisation of the nuclear mitotic apparatus (NuMA) protein in interphase cells
Authors: Yamauchi Yohei , Kiriyama Kazuya , Kimura Hiroshi , Nishiyama Yukihiro
Published: May 2008

The nuclear mitotic apparatus (NuMA) protein is a component of the nuclear matrix in interphase cells and an essential protein for the formation of mitotic spindle poles. We used herpes simplex virus (HSV), an enveloped DNA virus that replicates in the nucleus, to study the intra-nuclear dynamics of NuMA in infected cells. This study shows that NuMA is extensively modified following HSV infection, including phosphorylation of an unidentified site(s), and that it depends to an extent on viral DNA synthesis. Although NuMA is insoluble in uninfected interphase cells, HSV infection induced solubilisation and dynamic relocalisation of NuMA, whereupon the protein became excluded from viral replication compartments – sites of virus transcription and replication. Live cell, confocal imaging showed that NuMA localisation dramatically changed from the early stages (diffusely nuclear, excluding nucleoli) to late stages of infection (central diminuition, but remaining near the inner nuclear peripheries). In addition, NuMA knockdown using siRNA suggested that NuMA is important for efficient viral growth. In summary, we suggest that NuMA is required for efficient HSV infection, and identify further areas of research that address how the virus challenges host cell barriers.
Implicit particle wall boundary condition in molecular dynamics
Authors: Spijker P , ten Eikelder H M M , Markvoort A J , Nedea S V , Hilbers P A J
Published: May 2008

Thin film and nano-tube manufacturing, micro-channel cooling, and many other similar interesting techniques demand the prediction of heat transfer characteristics at the nanometre scale. In this respect, the transport properties at gas—solid and liquid—solid interfaces are very important. The processes at these interfaces can be studied in detail with molecular dynamics (MD) simulations. However, the computational cost involved in simulating the solid wall currently restrains the size of channels, which can be simulated. Therefore, the solid wall is sometimes replaced by boundary conditions, which often compromise on macroscopic quantities, such as density, temperature, pressure, and heat flux. In the current paper, a new particle wall boundary condition is presented, which is in good agreement with existing boundary conditions, but allows for the pressure calculation. This new boundary condition is based on averaging the contributions of an explicit solid wall and is derived using knowledge on common practices in MD algorithms, such as truncation and shifting. Moreover, it allows for different crystal lattices to be included in the new potential. The applicability of the new method is demonstrated by MD simulations of a gas between two parallel plates at different temperatures and densities. Furthermore, these simulations are compared with explicit wall simulations and existing boundary conditions.
A kinetic model for fluid—wall interaction
Authors: Frezzotti A , Gibelli L
Published: May 2008

A kinetic model of fluid—wall interaction is proposed, on the basis of a simple extension of Enskog theory of dense fluids. The model leads to a linear integro-differential equation which can be solved by the same statistical particle methods used to solve kinetic equations for dilute or dense fluids. The proposed model is applied to study the heat transport through a low density gas confined between two parallel walls kept at different temperatures. The results are compared with molecular dynamics simulations.
Towards multi-scale modelling of complex liquids using hybrid particle—continuum schemes
Authors: Delgado-Buscalioni R , Coveney P V , De Fabritiis G
Published: May 2008

Owing to the interplay between molecular and mesoscopic processes, the modelling and simulation of complex liquids at nano- and micron-scales require a multi-scale approach. A hybrid technique is proposed to handle multi-scale phenomena, which retains the full molecular nature of the system where it is of interest while coarse-graining it elsewhere. The method couples molecular dynamics (MD) and fluctuating hydrodynamics (FH) based on the Landau theory. Mean flows involving transport of transversal (shear) and longitudinal momentum (sound) are coupled across the interface of both MD and FH domains. Hydrodynamic fluctuations of mass and momentum are transferred, preserving consistency with hydrodynamics and thermodynamics. Here the hybrid method is illustrated by studying the reflection of water sound waves against a lipid (dimyristoylphosphatidylcholine) monolayer.
An inverse methodology for the rheology of a power-law non-Newtonian fluid
Authors: Bandulasena H C H , Zimmerman W B , Rees J M
Published: May 2008

The current paper presents a novel methodology for calculating the rheological para-meters for dilute aqueous solutions of a power-law non-Newtonian fluid, xanthan gum (XG). Previous studies have verified the fidelity of finite-element modelling of the Navier—Stokes equations for reproducing the velocity fields of XG solutions in a microfluidic T-junction with experimental observations obtained using micron resolution particle image velocimetry (μ-PIV). As the pressure-driven fluid is forced to turn the corner of the T-junction, a range of shear rates, and therefore viscosities, are produced within the flow system. Thus, a setup that potentially establishes the rheological profile of XG from a single experiment is selected. An inverse method based on finding the mapping between the statistical moments of the velocity field and the constitutive parameters of the viscosity profile demonstrated that such a system could potentially be used for the design of an efficient microfluidic rheometer. However, μ-PIV technology is expensive and the equipment is bulky. The current paper investigates whether different flow features could be used to establish the rheological profile.
Optically driven pumps and flow sensors for microfluidic systems
Authors: Mushfique H , Leach J , Di Leonardo R , Padgett M J , Cooper J M
Published: May 2008

This paper describes techniques for generating and measuring fluid flow in microfluidic devices. The first technique is for the multi-point measurement of fluid flow in microscopic geometries. The flow sensing method uses an array of optically trapped microprobe sensors to map out the fluid flow. The optical traps are alternately turned on and off such that the probe particles are displaced by the flow of the surrounding fluid and then retrapped. The particles' displacements are monitored by digital video microscopy and directly converted into velocity field values. The second is a method for generating flow within a microfluidic channel using an optically driven pump. The optically driven pump consists of two counter-rotating birefringent vaterite particles trapped within a microfluidic channel and driven using optical tweezers. The transfer of spin angular momentum from a circularly polarized laser beam causes the particles to rotate at up to 10 Hz. The pump is shown to be able to displace fluid in microchannels, with flow rates of up to 200 m−3 s−1 (200 fL s−1). In addition a flow sensing method, based upon the technique mentioned above, is incorporated into the system in order to map the magnitude and direction of fluid flow within the channel.
Hydrodynamics of Taylor flow in small channels: A Review
Authors: Angeli P , Gavriilidis A
Published: May 2008

The improved mass transfer characteristics of Taylor flow, make it an attractive flow pattern for carrying out gas—liquid operations in microchannels. Mass transfer characteristics are affected by the hydrodynamic properties of the flow such as thickness of the liquid film that surrounds the bubbles, bubble velocity, bubble and slug lengths, mixing, and flow circulation in the liquid slugs, and pressure drop. Experimental, theoretical, and modelling attempts to predict these properties are reviewed and relevant correlations are given. Most of these refer to capillaries but there are number of studies on square channels. In general, flow properties are well understood and predicted for fully formed Taylor bubbles in a developed flow and in clean systems, particularly in circular channels. However, the presence of impurities and their effect on interfacial tension cannot be fully accounted for. In addition, there is still uncertainty on the size of bubbles and slugs that form under certain operating and inlet conditions, while there is little information for channels with non-circular cross-sections.
Electro-osmotic flow in microchannels
Authors: Arnold A K , Nithiarasu P , Eng P F
Published: May 2008

In the current study, the modified Navier—Stokes equations together with the Poisson—Boltzmann and Laplace equations have been used to numerically model electro-osmotic flow (EOF) in straight microchannels. Flow experiments have been carried out using microchannels etched into silicon wafer surfaces. The numerical results from the present study have been compared against experimental data and an analytical solution. The results indicate that the numerical simulations are an accurate representation of EOF and that this model could be used as a tool in the design and analysis of complex EOF driven systems.
The Medical Ethics Committee of the British Medical Association – principles and pragmatism
Authors: Sheather Julian
Published: May 2008

This article gives an overview of the development, remit, structure and working of the British Medical Association's Medical Ethics Committee. It situates it within a brief history of the Association and gives examples of current work.
Parental authority, research interests and children's right to decide in medical research – an uneasy tension?
Authors: Swartling Ulrica , Helgesson Gert , Hansson Mats G , Ludvigsson Johnny
Published: May 2008

There is an increased focus on, and evidence of, children's capability to both understand and make decisions about issues relating to participation in medical research. At the same time there are divergent ideas of when, how and to what extent children should be allowed to decide for themselves. Furthermore, little is known about parents' views on these matters, an important issue since they often provide the formal consent.

In this questionnaire study of 2500 families in south-east Sweden (with and without research experience) we explored parents' views on issues relating to information, consent and research data. We found that parents are generally positive about supplying their child with individual information (93.3%; median age 7) and assuring the child's consent/assent to participation (74.3%; median age 12).

However, parents' views vary regarding the extent to which children should influence research data: as many as 47–61% of our sample were opposed to children's rights to decide about the use and storage of biological samples and natural history data.

Parents who are opposed to child consent and a wider influence on their research participation argue that parental authority and research quality are two important factors opposing enhanced child influence. Drawing on this, we underline the need to discuss how to balance children's rights against parental autonomy and research interests before implementing any standardized protocols granting children the right to consent and revoke data in long-term research.
Ethics and research governance: the views of researchers, health-care professionals and other stakeholders
Authors: Hallowell Nina , Cooke Sarah , Crawford Gill , Parker Michael , Lucassen Anneke
Published: May 2008

The objective of this study is to describe researchers', health-care providers' and other stakeholders' views of ethical review and research governance procedures. The study design involved qualitative semi-structured interviews. Participants included 60 individuals who either undertook research in the subspecialty of cancer genetics ( n = 40) or were involved in biomedical research in other capacities ( n = 20), e.g. research governance and oversight, patient support groups or research funding. While all interviewees observed that oversight is necessary to protect research participants, ethical review and research governance (ERG) arrangements were described negatively throughout these interviews. Interviewees identified a number of problems with ERG, including: over-bureaucratization, over-standardization of information requirements for different types of research, a lack of standardization in the types of information required by different committees for the same research and a lack of consistency in different committees' responses. A number of solutions were proposed including streamlining application procedures and harmonizing committees' responses and information requirements. Recent reports suggest that ethical review procedures and research governance arrangements threaten the possibility of undertaking clinical research in the UK, hence the introduction of the Integrated Research Application System (IRAS) is long overdue. However, while IRAS may solve some of the problems identified by interviewees, it remains to be seen to what extent it will impact upon the very negative perceptions of ethics and research governance procedures reported here.
Immunohistochemical Method Identifies Lymphovascular Invasion in a Majority of Oral Squamous Cell Carcinomas and Discriminates between Blood and Lymphatic Vessel Invasion
Authors: O'Donnell Rebekah K. , Feldman Michael , Mick Rosemarie , Muschel Ruth J.
Published: May 2008

Tumor invasion into blood and/or lymphatic channels is an important component of cancer staging and prognosis. Standard pathological methods do not provide sufficient contrast to discriminate between invasion into each type of vessel and are complicated by tissue retraction artifacts. We evaluated the ability of a triple-stain immunohistochemical method, combining cytokeratin, CD34, and podoplanin stains in a single section, to distinguish blood from lymphatic vascular invasion in oral squamous cell carcinoma and confirmed its results using multispectral analysis. The triple-stain method was significantly more sensitive in detecting invasive events than the standard hematoxylin and eosin staining method and easily discriminated between blood and lymphatic vessel invasion. Invasive events were present in blood and/or lymphatic vessels in the majority of patients with and without presentation of lymph node metastasis, indicating that vessel invasion in this cancer model is common and is not a rate-limiting step for lymph node metastasis.
Expression of Integrin-linked Kinase Is Increased in Differentiated Cells
Authors: Haase Michael , Gmach Christine C. , Eke Iris , Hehlgans Stephanie , Baretton Gustavo B. , Cordes Nils
Published: May 2008

Integrin-linked kinase (ILK), a mediator of β integrin signals, has emerged as a therapeutic target in malignant tumors. Because malignant transformation is accompanied by dedifferentiation, ILK expression was evaluated in diverse normal and tumor tissue samples with regard to tissue differentiation. In single sections and in a tissue microarray (323 tumor tissues, 181 normal tissues), immunohistochemistry was performed [ILK, Akt, phospho-Akt-S473, loricrin, transforming growth factor β2 (TGFβ2)], and staining intensities were semiquantitatively scored. Increased ILK expression was clearly associated with increased differentiation in normal gastrointestinal, neural, bone marrow, renal tissue, and in more differentiated areas of malignant tumors. ILK colocalized with its putative downstream target Akt and with loricrin or TGFβ2. Our findings clearly show that elevated levels of ILK are associated with cellular differentiation in high turnover tissues but not generally with a malignant phenotype. Our study indicates that ILK is not a general molecular target for cancer therapy but rather an indicator of differentiation. This manuscript contains online supplemental material at http://www.jhc.org . Please visit this article online to view these materials.
Hematopoietic Contribution to Skeletal Muscle Regeneration in Acid α-Glucosidase Knockout Mice
Authors: Mori Jun , Ishihara Yasunori , Matsuo Kensuke , Nakajima Hisakazu , Terada Naoto , Kosaka Kitaro , Kizaki Zenro , Sugimoto Tohru
Published: May 2008

Recent studies have shown that cells from bone marrow (BM) can give rise to differentiated skeletal muscle fibers. However, the mechanisms and identities of the cell types involved remain unknown. We performed BM transplantation in acid α-glucosidase (GAA) knockout mice, a model of glycogen storage disease type II, and our observations suggested that the BM cells contribute to skeletal muscle fiber formation. Furthermore, we showed that most CD45+:Sca1+ cells have a donor character in regenerating muscle of recipient mice. Based on these findings, CD45+:Sca1+ cells were sorted from regenerating muscles. The cell number was increased with granulocyte colony-stimulating factor after cardiotoxin injury, and the cells were transplanted directly into the tibialis anterior (TA) muscles of GAA knockout mice. Sections of the TA muscles stained with anti-laminin-α2 antibody showed that the number of CD45+:Sca1+ cells contributing to muscle fiber formation and glycogen levels were decreased in transplanted muscles. Our results indicated that hematopoietic stem cells, such as CD45+:Sca1+ cells, are involved in skeletal muscle regeneration.
Effect of Collection Tube Type and Preanalytical Handling on Myeloperoxidase Concentrations
Authors: Shih Jessie , Datwyler Saul A , Hsu Stephen C , Matias Matthew S , Pacenti David P , Lueders Christian , Mueller Christian , Danne Oliver , Möckel Martin
Published: May 2008

Background: Myeloperoxidase (MPO) has shown potential as a marker for cardiovascular disease. Limited studies have been published with a variety of sample types, resulting in a wide range of MPO values. Little is known or understood about the impact of collection tube type and preanalytical handling of specimens for MPO determination.

Method: MPO concentration was determined by use of the ARCHITECT® MPO research use assay, which is currently under development. Samples were collected into multiple anticoagulant collection tubes from donors and patients presenting to the emergency department with symptoms of acute coronary syndromes. Whole blood was stored on ice or at room temperature for predetermined time periods. We also evaluated serum and plasma after centrifugation followed by storage at room temperature, 2–8 °C, and below −10 °C.

Results: Baseline sample concentrations were dependent on collection tube type as well as handling conditions. MPO concentrations were consistently higher in samples collected in serum and heparin plasma tubes than in samples in EDTA or citrate tubes. Spike recovery was acceptable in all sera and plasma tested, indicating that the increased MPO concentrations were not due directly to an anticoagulant interference.

Conclusions: The collection tube type and preanalytical handling are critical for accurate and consistent MPO measurement. The preferred anticoagulant and tubes are the EDTA or EDTA plasma preparation tube. MPO concentrations in samples collected in these tubes are stable before centrifugation as whole blood as well as plasma after processing.
Rapid Determination of Monozygous Twinning with a Microfabricated Capillary Array Electrophoresis Genetic-Analysis Device1
Authors: Yeung Stephanie H I , Medintz Igor L , Greenspoon Susan A , Mathies Richard A
Published: May 2008

Background: Microfabricated genetic-analysis devices have great potential for delivering complex clinical diagnostic technology to the point of care. As a demonstration of the potential of these devices, we used a microfabricated capillary array electrophoresis (μCAE) instrument to rapidly characterize the familial and genotypic relationship of twins who had been assigned fraternal (dizygous) status at birth.

Methods: We extracted the genomic DNA from buccal samples collected from the twin sons, the parents, another sibling, and an unrelated control individual. We then carried out multiplex PCR amplification of sequences at 16 short tandem repeat loci commonly used in forensic identity testing. We simultaneously separated the amplicons from all of the individuals on a μCAE device and fluorescently detected the amplicons with single-base resolution in <30 min.

Results: The genotypic analysis confirmed the identical status of the twins and revealed, in conjunction with the medical data, that their twin status arose from the rarer dichorionic, diamniotic process.

Conclusions: The ability to rapidly analyze complex genetic samples with μCAE devices demonstrates that this approach can help meet the growing need for rapid genetics-based diagnostics.
Composition of callus resin of Norway spruce, Scots pine, European larch and Douglas fir
Authors: Holmbom Thomas , Reunanen Markku , Fardim Pedro
Published: May 2008

On damage of conifer trees, oleoresin is exuded onto the tree stem. The oleoresin is typically composed of monoterpenes and resin acids. It serves to protect the tree from dehydration and microbial attack. Callus resin, in the traditional German term “Überwallungsharz”, is a resin exuded from the callus tissue formed as the wound is closed by annual growth. These resins can usually be found as nodules or lumps on the rim of the closing wound. Both types of resin, collected from Picea abies, Pinus sylvestris, Larix decidua and Pseudotsuga menziesii, were analyzed separately by GC/GC-MS. Expectedly, the oleoresin samples were composed of resin acids. However, the callus resins were of a completely different composition as they are composed primarily of lignans and hydroxycinnamic acid derivatives. In addition, the L. decidua sample contained significant amounts of abietol and abietadiene. The P. abies and L. decidua callus resins were found to be essentially resin acid-free. The components identified in the callus resin samples have previously been identified as minor components in oleoresin and bark samples. The potential for the inadvertent inclusion of callus resin in previously analyzed samples of oleoresin, bark and ingrown (dead) knots is highlighted.
Compressive stress-strain properties of natural materials treated with aqueous NaOH
Authors: Ishikura Yukiko , Nakano Takato
Published: May 2008

Physical and cushioning properties of wood samples treated with various concentrations of NaOH aqueous solutions have been investigated based on compressive stress-strain curves. The shapes of curves changed essentially at NaOH concentrations above 10% as a threshold concentration. The stress-strain curves were analyzed based on the assumption that a rule of mixtures is applicable in the case of a very small range of displacement. The form factor n was also calculated. The values of n of the wood samples treated with NaOH whose concentration was higher than 10% were different from those of the wood samples treated with NaOH whose concentration was less than 10%. The shape changes, longitudinal contraction and twisting of the wood samples are related to NaOH concentration. The energy-absorption efficiency parameter E and ideality parameter I were calculated based on stress-strain curves according to the literature. Also, these parameters change above the threshold concentration of 10%. It was concluded that the cushioning properties of wood treated with alkali concentrations higher than 10% are improved. Due to the shape change of wood samples, the efficiency of energy-absorption properties is higher.
Identification of selected log characteristics from computed tomography images of sugar maple logs using maximum likelihood classifier and textural analysis
Authors: Wei Qiang , Leblon Brigitte , Chui Ying Hei , Zhang Shu Yin
Published: May 2008

In recent years, computed tomography (CT) was investigated to acquire internal log information non-destructively. This paper studied the feasibility of identifying internal log characteristics in CT images by means of maximum likelihood classifier. The log characteristics to be identified include heartwood, sapwood, inner bark, and knots in sugar maple. A total of 100 CT images were sampled from one log to develop the classifier and 20 images were selected from another log for validation. Besides spectral and distance features, textural features were also assessed. In total, nine of them were selected as the input features for the classifier based on the class separability analysis. The classifier developed in this study produced overall accuracies of 79.8% and 72.2% for the training images and the validation images, respectively. This study indicates that the developed maximum likelihood classifier relying on a combination of spectral, textural, and distance features may be applicable to identify the internal log characteristics in the CT images of sugar maple.
The reduction in the fibre saturation point of wood due to chemical modification using anhydride reagents: A reappraisal
Authors: Hill Callum A.S.
Published: May 2008

The data from a previous study of the moisture adsorption of Corsican pine modified with linear chain carboxylic acid anhydrides (acetic, propionic, butyric, valeric, hexanoic) has been reanalysed so that moisture content is reported as a percentage of cell wall mass only. As part of this work, the change in fibre saturation point (FSP, determined from fits of the Hailwood-Horrobin model) of the modified wood has been determined as a function of weight percentage gain (WPG). The change in FSP is not determined by the extent of hydroxyl substitution of the cell wall, but is related to WPG only (as reported previously). This is also true for the relationship between monolayer water, polylayer water, molecular weight per sorption site at saturation and WPG. However, there is no simple linear relationship between calculated FSP and WPG. When the FSP was determined by solute exclusion methods, the reduction thereof could be simply explained as due to bulking of the cell wall by the bonded acyl substituents. This is not the case when the FSP is determined from adsorption isotherms. This result is interpreted as an ambiguity of determination of FSP from projections of sorption isotherms. Differences in FSP determined by the two methods (sorption versus solute exclusion) are considered to be due to incomplete wetting of the lignocellulosic material when absorbing moisture from the initial dry state.
A comprehensive analysis of the relation of cellulose microfibril orientation and lignin content in the S2 layer of different tissue types of spruce wood (Picea abies (L.) Karst.)
Authors: Jungnikl Karin , Koch Gerald , Burgert Ingo
Published: May 2008

A possible relation between cellulose microfibril angle and lignin content in the S2 layer was investigated by X-ray diffraction and cellular UV microspectrophotometry on spruce tissues [Picea abies] with different structural features and chemical composition. A strong correlation was not found, neither for the individual tissue types nor for the compiled data of all tissues. As the data did not confirm the findings in former studies, further examinations are necessary concerning a possible general interrelation between microfibril angle and lignin content.
Micromorphological characteristics and lignin distribution in bamboo (Phyllostachys pubescens) degraded by the white rot fungus Lentinus edodes
Authors: Kim Jong Sik , Lee Kwang Ho , Cho Chang Hyun , Koch Gerald , Kim Yoon Soo
Published: May 2008

Little is known about the decay pattern of bamboo by wood decay fungi, and the information available on fungal degradation of wood from other plant taxa cannot form the basis for understanding wood decay in bamboo because of differences in lignin composition and distribution. The present work was undertaken to elucidate the degradation pattern of bamboo by a lignin-degrading white rot fungus Lentinus edodes using various microscopic techniques, with a particular focus on the relation of bamboo lignin composition to the decay patterns produced by this fungus. Small blocks of bamboo, Phyllostachys pubescens, were examined after 16 weeks of incubation with the white rot fungus L. edodes. The compound middle lamellae (CML), including the cell corner regions, were preferentially degraded at an early stage of decay, whereas the fiber secondary walls remained largely intact at this point. Bamboo fiber walls were also eroded from the cell lumen side but the extent of degradation was limited. The FT-IR bands assigned to lignin exhibited a significant decrease. Cellular ultraviolet microspectrophotometric investigation showed that CML and vessel walls were composed of not only guaiacyl and syringyl unit (GS lignin) but also grass lignin. In contrast, the secondary wall of fibers consisted mainly of the GS lignin. Even though the CML and vessel walls exhibited higher lignin concentration, these cell walls were nevertheless degraded. The preferential degradation of the CML over the fiber secondary walls strongly suggested the involvement of not only enzyme systems of the white rot fungus but also a relationship to physicochemical properties of bamboo cell walls, particularly the influence of lignin composition and distribution.
Standards for Preservation via Digital Recording to Microforms
Authors: Breslawski Robert
Published: May 2008

Modern film writers feature a variety of recording techniques, some based on traditional technology like CRT and Laser based Computer Output Microfilm (COM) and some with newer Light Emitting Diode (LED) technology. There are three key questions that seem to come up frequently from the user community. These can be summarized as follows:
Introduction: Accomplishing identity in bilingual interaction
Authors: Cashman Holly R. , Williams Ashley M.
Published: May 2008

In this brief introduction, the authors aim to describe the conversation analytic approach to bilingual conversation and the sociocultural linguistic approach to the study of identity in interaction that unite the contributions to this special issue.
Brought-along identities and the dynamics of ideology: Accomplishing bivalent stances in a multilingual interaction
Authors: Williams Ashley M.
Published: May 2008

This paper examines how the interconnected aspects of the stance triangle (Du Bois 2007) allow speakers to tap into multiple ideological layers as they take a stance and reveal intra-ethnic group tensions. Using a detailed interaction analysis of a Chinese American family's multilingual interaction, the paper explores how such ideological dynamics are associated with stance, and considers their relationship to emergent (Bucholtz and Hall 2004a; 2004b; 2005) and brought-along identities. Specifically, the paper analyzes how seemingly conflicting bivalent stances towards an increasingly dominant language (Mandarin) and its speakers discursively frame that group and their language as both similar to and different from the interaction's speakers and their own language (Cantonese). Through this downplaying and highlighting of similarities and differences, the participants' interaction captures not only the dynamics of an individual's identity but also the larger ideological dynamics of an ethnic community as its structure, and what it means to be a member, change over time.
Once a broker, always a broker: Non-professional interpreting as identity accomplishment in multigenerational Italian–English bilingual family interaction
Authors: Del Torto Lisa M.
Published: May 2008

This paper explores interpreting in three-generational Italian–English bilingual families as a complex language brokering activity. Recent studies approach non-professional interpreting as language brokering in which bilinguals (often children) interpret for non-bilinguals (adults) in institutional settings (Hall 2004; Valdés 2003). These studies focus on brokering between minority group ‘insiders’ and majority group ‘outsiders’. My research extends these approaches, focusing on brokering in Italian–English bilingual family meal-time conversations. Second-generation family members have served as interpreters for their parents in institutional contexts since migrating as children over fifty years ago. They extend this practice to the family context, brokering between first- and third-generation family members in two ways. Triggered interpreting occurs when speakers verbally request clarification or when second-generation family members perceive conversational sequence problems. Non-triggered interpreting is neither requested nor sequentially triggered. Second-generation family members report playing an intermediary role unifying flanking generations. They act to bridge perceived linguistic and cultural gaps between their Italian-dominant immigrant parents and their English-dominant Canadian/US-born children. Interpretation in multi-generational conversations is one way through which these bridging roles and identities are accomplished locally in mundane interaction. The analysis includes an examination of spontaneous conversational data and participants' metacommentary and retrospective accounts of language brokering.
Accomplishing difference in bilingual interaction: Translation as backwards-oriented medium repair
Authors: Greer Tim
Published: May 2008

Speakers often perform impromptu translations during bilingual interaction. Such translations can hold a wide variety of socio-pragmatic functions including reiteration, emphasis, recasting, and repair. When translations occur in multi-party talk where the interactants are of mixed linguistic proficiencies, they may also serve to include interlocutors who have been excluded from prior talk that was delivered in their weaker language. In this respect, translations re-partition interactants in an inclusive way. Making use of both conversation analysis (CA) and membership categorization analysis (MCA), this paper examines a collection of such post-exclusionary translations video-recorded among Japanese–English bilingual teenagers at an international school. A detailed sequential analysis of this bilingual practice reveals that the act of translation makes relevant various elements of the speakers' and recipients' identities. When a bilingual speaker offers a translation to someone, he or she casts the recipient in the category of novice (or ‘non-native’), often even despite real-time claims to comprehension from that person. Indeed, the study found that when non-natives offered a receipt token after a turn delivered in a medium that was not assumed to belong to them, it often prompted the speaker to repeat the prior turn in the recipient's preferred medium.
Finding identity: Theory and data
Authors: Bucholtz Mary , Hall Kira
Published: May 2008

This commentary responds to the papers in the special issue ‘Accomplishing identity in bilingual interaction’ and particularly to the use of Bucholtz and Hall's (2004a, 2004b, 2005) framework for the linguistic analysis of identities in interaction. The commentary focuses on the relationship between theory and empirical work, with attention to the role of ethnographic context in the analysis of both microlevel interaction and macrolevel sociopolitical and sociohistorical processes, the place of language ideologies in the interactional construction of bilingual identities, and the necessity to ground theoretical claims in rigorous empirical analysis.
Eigennamenerkennung zwischen morphologischer Analyse und Part-of-Speech Tagging: ein automatentheoriebasierter Ansatz
Authors: Didakowski Jörg , Geyken Alexander , Hanneforth Thomas
Published: May 2008

Previous rule-based approaches for Named Entity Recognition (NER) in German base NER on Part-of-Speech tagged texts. We present a new approach where NER is situated between morphological analysis and Part-of-Speech Tagging and model the NER-grammar entirely with weighted finite state transducers (WFST). We show that NER strategies like the resolution of proper noun/common noun or company-name/family-name ambiguities can be formulated as a best path function of a WFST. The frequently used second pass resolution of coreferential Named Entities can be formulated as a re-assignment of appropriate weights. A prototypical NE recognition system built on the basis of WSFT and large lexical resources was tested on a manually annotated corpus of 65,000 tokens. The results show that our system compares in recall and precision to existing rule-based approaches.
Robuste Auszeichnung Grammatischer Funktionen
Authors: Klenner Manfred
Published: May 2008

We introduce a robust and shallow approach for grammatical role labeling (dependency labeling) where data-driven and theory-driven aspects are combined in a principled way. A classifier provides empirically justified weights, linguistic theory contributes well-motivated global restrictions, both are combined under the regiment of optimization. The empirical results of our approach are promising. However, we have made idealized assumptions (small inventory of dependency relations and treebank-derived chunks) that clearly must be replaced by a realistic setting.
Annotation for and Robust Parsing of Discourse Structure on Unrestricted Texts
Authors: Baldridge Jason , Asher Nicholas , Hunter Julie
Published: May 2008

Predicting discourse structure on naturally occurring texts and dialogs is challenging and computationally intensive. Attempts to construct hand-built systems have run into problems both in how to specify the required knowledge and how to perform the necessary computations in an efficient manner. Data-driven approaches have recently been shown to be successful for handling challenging aspects of discourse without using lots of fine-grained semantic detail, but they require annotated material for training. We describe our effort to annotate Segmented Discourse Representation Structures on Wall Street Journal texts, arguing that graph-based representations are necessary for adequately capturing the dependencies found in the data. We then explore two data-driven parsing strategies for recovering discourse structures. We show that the generative PCFG model of Baldridge & Lascarides (2005b) is inherently limited by its inability to incorporate new features when learning from small data sets, and we show how recent developments in dependency parsing and discriminative learning can be utilized to get around this problem and thereby improve parsing accuracy. Results from exploratory experiments on Verbmobil dialogs and our annotated news wire texts are given; these results suggest that these methods do indeed enhance performance and have the potential for significant further improvements by developing richer feature sets.