bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence of Programmed Cell Death in Post-Phloem Transport Cells of the Maternal Pedicel Tissue in Developing Caryopsis of Maize
Authors: Kladnik Ales , Chamusco Karen , Dermastia Marina , Chourey Prem
Published: November 2004

We present cellular- and ultracellular-level studies here to show developmental programmed cell death (PCD) of placento-chalazal (P-C) cell layers in maternal pedicel tissue in developing caryopses of normal seed (Mn1) and in the invertase-deficient miniature (mn1) seed mutant in maize (Zea mays). PCD was evidenced by loss of nuclei and all subcellular membranous organizations in many P-C layers. The terminal deoxynucleotidyl transferase-mediated X-dUTP nick-end labeling (TUNEL) stain that is diagnostic of apoptotic-like PCD identified spatially and temporally two distinctive subdomains, which coincided with nucellar and integumental P-C layers based on their developmental origins. The early phase of PCD in the nucellar P-C was TUNEL negative and was specific to only the fertilized caryopses, indicating that the signaling for PCD in these maternal cells originated in the zygotic tissues. In fact, the initiation of PCD coincided with endosperm cellularization and was rapidly and coordinately completed prior to the beginning of the major storage phase in endosperm. Cell shape in these cell layers was also influenced by the genotype of filial endosperm. The later phase of PCD was restricted to the integumental P-C layers underneath the nucellar cells and was TUNEL positive in both genotypes. The two subdomains of the P-C layers were also distinguishable by unique cell wall-associated phenolic compounds. Based on collective evidence, we infer that the nucellar PCD may have osmolytic etiology and may lead to activation of the post-phloem transport function of the P-C layer, whereas the integumental PCD was senescent related, in particular, protecting the maturing seed against microbes that may be transported from the maternal tissue.
Arabidopsis HMA2, a Divalent Heavy Metal-Transporting PIB-Type ATPase, Is Involved in Cytoplasmic Zn2+ Homeostasis
Authors: Eren Elif , Argüello José M.
Published: November 2004

PIB-type ATPases transport heavy metal ions (Cu+, Cu2+, Zn2+, Cd2+, Co2+, etc.) across biological membranes. Several members of this subfamily are present in plants. Higher plants are the only eukaryotes where putative Zn2+-ATPases have been identified. We have cloned HMA2, a PIB-ATPase present in Arabidopsis (Arabidopsis thaliana), and functionally characterized this enzyme after heterologous expression in yeast (Saccharomyces cerevisiae). HMA2 is a Zn2+-dependent ATPase that is also activated by Cd2+ and, to a lesser extent, by other divalent heavy metals (Pb2+, Ni2+, Cu2+, and Co2+). The enzyme forms an acid-stable phosphorylated intermediate and is inhibited by vanadate. HMA2 interacts with Zn2+ and Cd2+ with high affinity (Zn2+K1/2 = 0.11 ± 0.03 μm and Cd2+K1/2 = 0.031 ± 0.007 μm). However, its activity is dependent on millimolar concentrations of Cys in the assay media. Zn2+ transport determinations indicate that the enzyme drives the outward transport of metals from the cell cytoplasm. Analysis of HMA2 mRNA suggests that the enzyme is present in all plant organs and transcript levels do not change in plants exposed to various metals. Removal of HMA2 full-length transcript results in Zn2+ accumulation in plant tissues. hma2 mutant plants also accumulate Cd2+ when exposed to this metal. These results suggest that HMA2 is responsible for Zn2+ efflux from the cells and therefore is required for maintaining low cytoplasmic Zn2+ levels and normal Zn2+ homeostasis.
Cesium Toxicity in Arabidopsis
Authors: Hampton Corrina R. , Bowen Helen C. , Broadley Martin R. , Hammond John P. , Mead Andrew , Payne Katharine A. , Pritchard Jeremy , White Philip J.
Published: November 2004

Cesium (Cs) is chemically similar to potassium (K). However, although K is an essential element, Cs is toxic to plants. Two contrasting hypotheses to explain Cs toxicity have been proposed: (1) extracellular Cs+ prevents K+ uptake and, thereby, induces K starvation; and (2) intracellular Cs+ interacts with vital K+-binding sites in proteins, either competitively or noncompetitively, impairing their activities. We tested these hypotheses with Arabidopsis (Arabidopsis thaliana). Increasing the Cs concentration in the agar ([Cs]agar) on which Arabidopsis were grown reduced shoot growth. Increasing the K concentration in the agar ([K]agar) increased the [Cs]agar at which Cs toxicity was observed. However, although increasing [Cs]agar reduced shoot K concentration ([K]shoot), the decrease in shoot growth appeared unrelated to [K]shoot per se. Furthermore, the changes in gene expression in Cs-intoxicated plants differed from those of K-starved plants, suggesting that Cs intoxication was not perceived genetically solely as K starvation. In addition to reducing [K]shoot, increasing [Cs]agar also increased shoot Cs concentration ([Cs]shoot), but shoot growth appeared unrelated to [Cs]shoot per se. The relationship between shoot growth and [Cs]shoot/[K]shoot suggested that, at a nontoxic [Cs]shoot, growth was determined by [K]shoot but that the growth of Cs-intoxicated plants was related to the [Cs]shoot/[K]shoot quotient. This is consistent with Cs intoxication resulting from competition between K+ and Cs+ for K+-binding sites on essential proteins.
Ca2+ Dynamics in a Pollen Grain and Papilla Cell during Pollination of Arabidopsis
Authors: Iwano Megumi , Shiba Hiroshi , Miwa Teruhiko , Che Fang-Sik , Takayama Seiji , Nagai Takeharu , Miyawaki Atsushi , Isogai Akira
Published: November 2004

Ca2+ dynamics in the growing pollen tube have been well documented in vitro using germination assays and Ca2+ imaging techniques. However, very few in vivo studies of Ca2+ in the pollen grain and papilla cell during pollination have been performed. We expressed yellow cameleon, a Ca2+ indicator based on green fluorescent protein, in the pollen grains and papilla cells of Arabidopsis (Arabidopsis thaliana) and monitored Ca2+ dynamics during pollination. In the pollen grain, [Ca2+]cyt increased at the potential germination site soon after hydration and remained augmented until germination. As in previous in vitro germination studies, [Ca2+]cyt oscillations were observed in the tip region of the growing pollen tube, but the oscillation frequency was faster and [Ca2+]cyt was higher than had been observed in vitro. In the pollinated papilla cell, remarkable increases in [Ca2+]cyt occurred three times in succession, just under the site of pollen-grain attachment. [Ca2+]cyt increased first soon after pollen hydration, with a second increase occurring after pollen protrusion. The third and most remarkable [Ca2+]cyt increase took place when the pollen tube penetrated into the papilla cell wall.
Molecular Physiological Analysis of the Two Plastidic ATP/ADP Transporters from Arabidopsis
Authors: Reiser Jens , Linka Nicole , Lemke Lilia , Jeblick Wolfgang , Neuhaus H. Ekkehard
Published: November 2004

Arabidopsis (Arabidopsis thaliana) possesses two isoforms of plastidic ATP/ADP transporters (AtNTT1 and AtNTT2) exhibiting similar biochemical properties. To analyze the function of both isoforms on the molecular level, we examined the expression pattern of both genes by northern-blot analysis and promoter-β-glucuronidase fusions. AtNTT1 represents a sugar-induced gene mainly expressed in stem and roots, whereas AtNTT2 is expressed in several Arabidopsis tissues with highest accumulation in developing roots and young cotyledons. Developing lipid-storing seeds hardly contained AtNTT1 or -2 transcripts. The absence of a functional AtNTT1 gene affected plant development only slightly, whereas AtNTT2∷T-DNA, AtNTT1-2∷T-DNA, and RNA interference (RNAi) plants showed retarded plant development, mainly characterized by a reduced ability to generate primary roots and a delayed chlorophyll accumulation in seedlings. Electron microscopic examination of chloroplast substructure also revealed an impaired formation of thylakoids in RNAi seedlings. Moreover, RNAi- and AtNTT1-2∷T-DNA plants showed reduced accumulation of the nuclear-encoded protein CP24 during deetiolation. Under short-day conditions reduced plastidic ATP import capacity correlates with a substantially reduced plant growth rate. This effect is absent under long-day conditions, strikingly indicating that nocturnal ATP import into chloroplasts is important. Plastidic ATP/ADP transport activity exerts significant control on lipid synthesis in developing Arabidopsis seeds. In total we made the surprising observation that plastidic ATP/ADP transport activity is not required to pass through the complete plant life cycle. However, plastidic ATP/ADP-transporter activity is required for both an undisturbed development of young tissues and a controlled cellular metabolism in mature leaves.
Unexpected Deposition Patterns of Recombinant Proteins in Post-Endoplasmic Reticulum Compartments of Wheat Endosperm
Authors: Arcalis Elsa , Marcel Sylvain , Altmann Friedrich , Kolarich Daniel , Drakakaki Georgia , Fischer Rainer , Christou Paul , Stoger Eva
Published: November 2004

Protein transport within cereal endosperm cells is complicated by the abundance of endoplasmic reticulum (ER)-derived and vacuolar protein bodies. For wheat storage proteins, two major transport routes run from the ER to the vacuole, one bypassing and one passing through the Golgi. Proteins traveling along each route converge at the vacuole and form aggregates. To determine the impact of this trafficking system on the fate of recombinant proteins expressed in wheat endosperm, we used confocal and electron microscopy to investigate the fate of three recombinant proteins containing different targeting information. KDEL-tagged recombinant human serum albumin, which is retrieved to the ER lumen in leaf cells, was deposited in prolamin aggregates within the vacuole of endosperm cells, most likely following the bulk of endogenous glutenins. Recombinant fungal phytase, a glycoprotein designed for secretion, was delivered to the same compartment, with no trace of the molecule in the apoplast. Glycan analysis revealed that this protein had passed through the Golgi. The localization of human serum albumin and phytase was compared to that of recombinant legumin, which contains structural targeting information directing it to the vacuole. Uniquely, legumin accumulated in the globulin inclusion bodies at the periphery of the prolamin bodies, suggesting a different mode of transport and/or aggregation. Our results demonstrate that recombinant proteins are deposited in an unexpected pattern within wheat endosperm cells, probably because of the unique storage properties of this tissue. Our data also confirm that recombinant proteins are invaluable tools for the analysis of protein trafficking in cereals.
The Arabidopsis Trehalose-6-P SynthaseAtTPS1Gene Is a Regulator of Glucose, Abscisic Acid, and Stress Signaling
Authors: Avonce Nelson , Leyman Barbara , Mascorro-Gallardo José O. , Van Dijck Patrick , Thevelein Johan M. , Iturriaga Gabriel
Published: November 2004

In Arabidopsis (Arabidopsis thaliana), trehalose is present at almost undetectable levels, excluding its role as an osmoprotectant. Here, we report that overexpression of AtTPS1 in Arabidopsis using the 35S promoter led to a small increase in trehalose and trehalose-6-P levels. In spite of this, transgenic plants displayed a dehydration tolerance phenotype without any visible morphological alterations, except for delayed flowering. Moreover, seedlings overexpressing AtTPS1 exhibited glucose (Glc)- and abscisic acid (ABA)-insensitive phenotypes. Transgenic seedlings germinated on Glc were visibly larger with green well-expanded cotyledonary leaves and fully developed roots, in contrast with wild-type seedlings showing growth retardation and absence of photosynthetic tissue. An ABA dose-response experiment revealed a higher germination rate for transgenic plants overexpressing AtTPS1 showing insensitive germination kinetics at 2.5 μm ABA. Interestingly, germination in the presence of Glc did not trigger an increase in ABA content in plants overexpressing AtTPS1. Expression analysis by quantitative reverse transcription-PCR in transgenic plants showed up-regulation of the ABI4 and CAB1 genes. In the presence of Glc, CAB1 expression remained high, whereas ABI4, HXK1, and ApL3 levels were down-regulated in the AtTPS1-overexpressing lines. Analysis of AtTPS1 expression in HXK1-antisense or HXK1-sense transgenic lines suggests the possible involvement of AtTPS1 in the hexokinase-dependent Glc-signaling pathway. These data strongly suggest that AtTPS1 has a pivotal role in the regulation of Glc and ABA signaling during vegetative development.
Mesoscopic residual stresses of plastic origin in zirconium: interpretation of X-ray diffraction results
Authors: Gloaguen D. , François M. , Guillen R.
Published: November 2004

Complementary methods have been used to analyse residual stresses in a heat-treated Zr702 sheet which had undergone uniaxial plastic deformation: X-ray diffraction and self-consistent models. The elastoplastic self-consistent model has been used to simulate the experiments and exhibits agreement with experimental data. X-ray diffraction analysis in the rolling direction shows opposite stress values for {10\bar{1}4} and {20\bar{2}2} planes, respectively. The measured strains were generated by an anisotropic plastic deformation. The comparison between ∊ϕψversussin2ψ and simulations confirms that prismatic slip is the main active deformation mode. Plastic incompatibility stress in X-ray measurements should be taken into account in order to make a correct interpretation of the experimental data.
The characterization of crystalline particle growth in TiNi thin films
Authors: Li Yonghua , Meng Fanling , Wang Jinkuan , Wang Yuming
Published: November 2004

Small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD) have been used to investigate sputter-deposited TiNi films annealed at 773 K for 3, 8, 13, 15, 25 and 60 min. The specific interfacial area of the crystalline–amorphous two-phase system increases at the beginning of annealing, achieves a maximum after about 13 min and decreases on further annealing, whereas the radius of gyration of the crystalline particle increases during the annealing process. The prominent increase of the specific interfacial area and the slight increase of the radius of gyration of the crystalline particle at the beginning of annealing are correlated with the nucleation of the crystalline particle. The subsequent decrease of the specific interfacial area is correlated with the growth of the crystalline particles.
High-resolution strain mapping in bulk samples using full-profile analysis of energy-dispersive synchrotron X-ray diffraction data
Authors: Steuwer A. , Santisteban J. R. , Turski M. , Withers P. J. , Buslaps T.
Published: November 2004

The feasibility of both high spatial and strain resolution is demonstrated using high-energy X-rays between 100 and 300 keV on beamline ID15A at the ESRF. The data analysis was performed using a multiple-peak Pawley-type refinement on the recorded spectra. An asymmetric peak profile was necessary in order to obtain a point-to-point uncertainty of 10−5. The measurements have been validated with complementary techniques or reference data.
A high-energy triple-axis X-ray diffractometer for the study of the structure of bulk crystals
Authors: Seitz C. , Weisser M. , Gomm M. , Hock R. , Magerl A.
Published: November 2004

A triple-axis diffractometer for high-energy X-ray diffraction is described. A 450 kV/4.5 kW stationary tungsten X-ray tube serves as the X-ray source. Normally, 220 reflections of thermally annealed Czochralski Si are employed for the monochromator and analyser. Their integrated reflectivity is about ten times higher than the ideal crystal value. With the same material as the sample, and working with the WKα line at 60 keV in symmetric Laue geometry for all axes, the full width at half-maximum (FWHM) values for the longitudinal and transversal resolution are 2.5 × 10−3and 1.1 × 10−4for ΔQ/Q, respectively, and the peak intensity for a non-dispersive setting is 3000 counts s−1. In particular, for a double-axis mode, an energy well above 100 keV from theBremsstrahlungspectrum can be used readily. High-energy X-rays are distinguished by a high penetration power and materials of several centimetre thickness can be analysed. The feasibility of performing experiments with massive sample environments is demonstrated.
Phase composition depth profiles using spatially resolved energy dispersive X-ray diffraction
Authors: Jupe Andrew C. , Stock Stuart R. , Lee Peter L. , Naik Nikhila N. , Kurtis Kimberly E. , Wilkinson Angus P.
Published: November 2004

Spatially resolved energy dispersive X-ray diffraction, using high-energy synchrotron radiation (∼35–80 keV), was used nondestructively to obtain phase composition profiles along the radii of cylindrical cement paste samples to characterize the progress of the chemical changes associated with sulfate attack on the cement. Phase distributions were acquired to depths of ∼4 mm below the specimen surface with sufficient spatial resolution to discern features less than 200 µm thick. The experimental and data analysis methods employed to obtain quantitative composition profiles are described. The spatial resolution that could be achieved is illustrated using data obtained from copper cylinders with a thin zinc coating. The measurements demonstrate that this approach is useful for nondestructively visualizing the sometimes complex transformations that take place during sulfate attack on cement-based materials. These transformations can be spatially related to microstructure as seen by computed microtomography.
Sodium High blood pressure and research needs
Authors: Brady Maeve
Published: November 2004

High blood pressure contributes to the risk of heart disease and stroke. Reducing sodium in the diet, as an adjunct to drug therapy, would benefit those with established hypertension. Whilst the medical debate about sodium and hypertension continues, researchers believe that eating more fruit and vegetables can help to lower blood pressure. The UK food and drink manufacturing industry supports a national consumer information programme that promotes healthy eating, and in particular an increased consumption of all types of fruit and vegetables. Additional research could improve understanding of the major effects of nutrient interactions on blood pressure.
Intrinsic optical fibre current sensors
Authors: Rogers Alan J.
Published: November 2004

Passive optical‐fibre current measurement devices offer technical and economic advantages for power‐system use. Methods which have been examined for implementing such devices are discussed together with sources of noise and noise minimisation procedures. The article includes new ideas for vibration immunity with experimental results.
New technology for subsea laser imaging and ranging system for inspection and mapping
Authors: Evans Paul M. , Klepsvik John O. , Bjarnar Morten L.
Published: November 2004

Laser imaging and ranging systems offer 3‐D imaging of video quality at distances four to five times greater than conventional video and photographic systems. The Spotmap system is based on the laser radar approach, using a pulsed green solid state laser as a transmitter and detecting the time‐of‐flight and peak intensity of the reflected pulses. Images and maps of underwater scenes are obtained by scanning the laser beam across the objects in a raster pattern using a two‐axis optical scanner. The system can be used both in linescan and 2D scan modes of operation such that images can be obtained either from the linear movement of the remotely operated vehicle or from a stationary position. The system has a 90∞ cross‐track FOV and is capable of processing 8,000 points per second, which gives an imaging resolution comparable to video at ROV speeds up to 2m/s.
A stereovision system for underwater, remotely operated vehicles
Authors: Maddalena D. , Zampato M. , Favaretto M.
Published: November 2004

In the paper, “TV‐trackmeter”, a stereoscopic measuring system developed by Tecnomare, is presented, some recent innovations and upgrading are described, and its reliable use in hostile environments proved. The latest release of the device implements highlighted featuring capabilities such as 3D measuring, automatic mapping, false colour depth‐maps, geometric modelling, multi‐point tracking, recording/retrieving of stereo pair images, and use of new and more powerful hardware. A theoretical introduction to the operating mode of a stereoscopic device, followed by an error propagation analysis is included. A brief description is also given of the accuracy of the device, i.e. pose detection (position and attitude estimation) of the scene objects. An evaluation of the tracking speed capability is provided. Some examples are shown of trials carried out within a nuclear power plant and underwater. Two further applications for this system are described.
Advancements in infra‐red array detectors
Authors: Monkman Gareth J.
Published: November 2004

Despite many advances during the last decade in both infra‐red sensor and solid state camera technology, until now little headway has been made in the production of cost‐effective semiconductor sensor arrays capable of operating far into the infra‐red. Old ideas, renewed by the capabilities offered by the latest micromachine technology, may change all this. Reviews the problems associated with building such sensor arrays before introducing some interesting new research results.
A strategy for accurate guidance of a manipulator using laser interferometry‐based sensing technique
Authors: Shirinzadeh Bijan , Loo Teoh Pek , Wei Foong Chee , Liu YongDong
Published: November 2004

Laser interferometry‐based sensing (LIS) technique has been proposed and established recently to track and perform dynamic measurements on a moving end‐effector of a robot manipulator. In this paper, a technique using LIS system to perform guidance of a manipulator is proposed. The LIS system is used as a sensor to guide the end‐effector of a robot manipulator. This is to be accomplished through the implementation of guidance error determination and compensation, and path generation in the control algorithm. This technique can be used to accurately guide the manipulator’s end‐effector to a specified location or along a specified path with a high level of accuracy. The structure and various components within the system and the control strategy are also presented.
The implementation of quality management initiatives in the context of organisational learning
Authors: Roche Evelyn
Published: November 2004

As a prerequisite to pursuing business excellence companies build learning organisations and companies that want to transform their organisations to a continuous improvement philosophy need to embrace the notion of organisational learning, whether they like it or not. Aims to analyse quality management initiatives in the context of organisational learning. At the start of this research Excellence Ireland and Advanced Management Technology secured the participation of four manufacturing organisations. These companies wanted to implement the Business Excellence Model. They were encouraged to form a network called “Best in class”. Presents a review of the organisational learning literature; the research agenda; sample design and the methodology. Presents a case history of a company which has implemented quality management initiatives. Discusses the findings and analysis, and draws a conclusion in the context of organisational learning. Focuses on presenting the organisational learning literature and not the quality management literature.
Changing employment relations, new organizational models and the capability to use idiosyncratic knowledge
Authors: Fuchs Manfred
Published: November 2004

Aims to solve the problem of why newer organizational models are losing their capability to elaborate and develop valuable firm‐specific sources of competitive advantages. Devotes special attention to the interdependent link between the rise of flexible employment relations and the diminishing capability of newer organizational models to sustain the sources of firm‐specific competitive advantages. Argues that an organization which relies heavily on flexible workforces will lose its ability to bind, retain as well as attract its skilled and most important idiosyncratic workers. First describes how the traditional organizational order, known as Fordism, is challenged and what newer organizational models claim to offer. Develops two different conceptional models that depict the hypothesized interdependent relation between the quality and degree of employment relations and the firms’ capability to use and elaborate the idiosyncratic knowledge of its workforce. Shows that the workforce has to be recognized as an increasingly non‐replicable, intangible, difficult to replicate firm‐specific source of sustainable advantage that cannot easily be imitated by competitors if retained and bound within organizational boundaries.
Institutionalizing organizational change through cascade training
Authors: Jacobs Ronald L.
Published: November 2004

Institutionalization of organizational change should be considered a part of the change process, regardless of the nature of the change. After initial success, many change efforts eventually fail. The article discusses a framework for institutionalizing change and introduces cascade training to ensure the employee competence to carry out the change. The article introduces four designs of cascade training based on the change target, change purpose, the training outcomes, organizational characteristics and characteristics of the intervention.
The influence of focus group feedback on the three organizational levels of an international retailer
Authors: Brooks Kit
Published: November 2004

Investigates the impact of three organizational levels – organizational, process and individual/job – on the current effectiveness of meeting goals regarding holiday sales and product display in an international retailer. Explores the need for change by means of a three‐part project using seven focus groups with 38 district managers and 84 department managers from each region of the continental USA except the West Coast. Identifies, from the results of the group feedback, changes that were felt to be needed in the three organizational levels. Concludes that a holistic approach is needed in order to enhance performance rather than approaching performance issues from a unilateral perspective.
Organisational learning: building the future of a school
Authors: Davies Brent , Ellison Linda
Published: November 2004

This article builds on an earlier one which we published in this journal, in which we proposed a new model for school planning. In proposing the new model, we recognised that it provided a framework for school planning but that it did not discuss the process of building a plan for the school’s future. Here we explain how the new model has developed and how we now propose to link it to important aspects of organisational learning such as the development of the school’s core purpose and values. This linkage, and the ongoing involvement of a range of stakeholders, should help to ensure that the school learns strategically so that plans are effective and there is no gap between strategy and implementation.
Corporate strategy R&D and technology transfer in the European pharmaceutical industry: research findings
Authors: Simango Chris C.B.
Published: November 2004

Discusses the extent to which American, European and Japanese pharmaceutical multinational enterprises (MNE) with subsidiaries in the Republic of Ireland have localised specific forms of R&D and contributed to technology transfer. Reports on a survey in which chief executive officers of Irish‐based MNE subsidiaries responded to mailed questionnaires. The reasons for corporate management to choose such operational strategic thrusts at business level have been highlighted with a view to focus on the degree to which Ireland is developing its pharmaceutical industrial base, as a result of attracting export‐led global pharmaceutical multinationals.
Cultural characteristics prevalent in the Chinese negotiation process
Authors: Seng Woo Hong , Prud’homme Celine
Published: November 2004

This paper examines the prevalent characteristics inherent in negotiating with individuals and organisations in China. A successful negotiation with Chinese needs to be conducted in a way that is acceptable to the Chinese. Supported by literature, six cases are used to determine and illustrate these characteristics on the challenges facing the European negotiator in China. These include ways to influence the Chinese side and awareness of the cultural dynamics that account for Chinese behaviour in negotiations. Research results show that any European negotiator needs to be aware of the prevalent negotiation characteristics of status, face, trust, friendship, Guanxi network, ambiguity, patience and Chinese protocols. Their knowledge is essential to avoid any misunderstanding or tension when dealing with the Chinese. Evidence from this paper suggests that any European negotiator should understand Chinese behaviour before entering into a business relationship and to keep it going smoothly.
Environmental determinants of export decision making: conceptual issues regarding the domestic market
Authors: Morgan Robert E.
Published: November 2004

The domestic market environment is host to complex phenomena that affect, and are affected by, the actions and activities of both exporting and non‐exporting firms. In this regard, a significant degree of research attention has been devoted to overseas competitive environments and the nature of market selection made by exporting firms. However, very limited research work has been dedicated to the domestic market environment confronted by the non‐exporting firm and its influence on export strategy development. It is argued there that domestic market environment can significantly affect the “fit” between the resources and capabilities of the firm and the overseas opportunities and threats that are perceived. Accordingly, this paper: reviews the literature associated with the domestic market environment, firm internationalization, the concept of “strategic fit” and the factors and influences present in the domestic market environment; and, presents a series of conceptual propositions concerning the respective relationships between competitive intensity, technological turbulence and product‐market turbulence, and export strategy development at the pre‐export level.
Optical fibre sensing for intelligent monitoring
Authors: Jones Gordon R.
Published: November 2004

Optical sensors already form important elements of optical fibre based transducers for measuring a wide range of parameters. This viewpoint emphasises the major potential provided for such sensors by incorporation as components of intelligent monitoring systems.
Absence of convection in a perfect gas
Authors: Ciattoni Alessandro , Di Porto Paolo , Crosignani Bruno
Published: November 2004

We investigate the conditions under which a perfect gas subject to a three-dimensional external conservative field is in mechanical equilibrium without being in thermal equilibrium, that is, with a nonvanishing temperature gradient. We find the class of potentials for which this behavior is possible. In particular, gravitational, Coulomb, and centrifugal fields are shown to belong to this class. We obtain the functional form of the temperature field that assures the absence of convection and obtain the stability condition for mechanical equilibrium.
Understanding the Fano resonance through toy models
Authors: Bandopadhyay Swarnali , Dutta-Roy Binayak , Mani H. S.
Published: November 2004

The Fano resonance involves the mixing between the continuum states of the elastic channel and a quasi-bound discrete state of the inelastic channel. The underlying ideas have recently attracted attention in connection with interference effects in quantum wires and mesoscopic transport phenomena. Simple toy models are discussed to illustrate the subtle aspects of the Fano resonance.
Global Identification of Human Transcribed Sequences with Genome Tiling Arrays
Authors: Bertone Paul , Stolc Viktor , Royce Thomas E. , Rozowsky Joel S. , Urban Alexander E. , Zhu Xiaowei , Rinn John L. , Tongprasit Waraporn , Samanta Manoj , Weissman Sherman , Gerstein Mark , Snyder Michael
Published: November 2004

Elucidating the transcribed regions of the genome constitutes a fundamental aspect of human biology, yet this remains an outstanding problem. To comprehensively identify coding sequences, we constructed a series of high-density oligonucleotide tiling arrays representing sense and antisense strands of the entire nonrepetitive sequence of the human genome. Transcribed sequences were located across the genome via hybridization to complementary DNA samples, reverse-transcribed from polyadenylated RNA obtained from human liver tissue. In addition to identifying many known and predicted genes, we found 10,595 transcribed sequences not detected by other methods. A large fraction of these are located in intergenic regions distal from previously annotated genes and exhibit significant homology to other mammalian proteins.
Observation of the Spin Hall Effect in Semiconductors
Authors: Kato Y. K. , Myers R. C. , Gossard A. C. , Awschalom D. D.
Published: November 2004

Electrically induced electron-spin polarization near the edges of a semiconductor channel was detected and imaged with the use of Kerr rotation microscopy. The polarization is out-of-plane and has opposite sign for the two edges, consistent with the predictions of the spin Hall effect. Measurements of unstrained gallium arsenide and strained indium gallium arsenide samples reveal that strain modifies spin accumulation at zero magnetic field. A weak dependence on crystal orientation for the strained samples suggests that the mechanism is the extrinsic spin Hall effect.
Resistance to Vesicular Stomatitis Virus Infection Requires a Functional Cross Talk between the Eukaryotic Translation Initiation Factor 2α Kinases PERK and PKR
Authors: Baltzis Dionissios , Qu Li-Ke , Papadopoulou Stavroula , Blais Jaime D. , Bell John C. , Sonenberg Nahum , Koromilas Antonis E.
Published: November 2004

Phosphorylation of the alpha (α) subunit of the eukaryotic translation initiation factor 2 (eIF2) leads to the inhibition of protein synthesis in response to diverse stress conditions, including viral infection. The eIF2α kinase PKR has been shown to play an essential role against vesicular stomatitis virus (VSV) infection. We demonstrate here that another eIF2α kinase, the endoplasmic reticulum-resident protein kinase PERK, contributes to cellular resistance to VSV infection. We demonstrate that mouse embryonic fibroblasts (MEFs) from PERK
−/−
mice are more susceptible to VSV-mediated apoptosis than PERK
+/+
MEFs. The higher replication capacity of VSV in PERK
−/−
MEFs results from their inability to attenuate viral protein synthesis due to an impaired eIF2α phosphorylation. We also show that VSV-infected PERK
−/−
MEFs are unable to fully activate PKR, suggesting a cross talk between the two eIF2α kinases in virus-infected cells. These findings further implicate PERK in virus infection, and provide evidence that the antiviral and antiapoptotic roles of PERK are mediated, at least in part, via the activation of PKR.
Identification of Cellular Cofactors for Human Immunodeficiency Virus Replication via a Ribozyme-Based Genomics Approach
Authors: Waninger Shani , Kuhen Kelli , Hu Xiuyuan , Chatterton Jon E. , Wong-Staal Flossie , Tang Hengli
Published: November 2004

Ribozymes are small, catalytic RNA molecules that can be engineered to down-regulate gene expression by cleaving specific mRNA. Here we report the selection of hairpin ribozymes that inhibit human immunodeficiency virus (HIV) replication from a combinatorial ribozyme library. We identified a total of 17 effective ribozymes, each capable of inhibiting HIV infection of human CD4
+
cells. These ribozymes target diverse steps of the viral replication cycle, ranging from entry to transcription. One ribozyme suppressed HIV integration and transcription by inhibiting the expression of the Ku80 subunit of the DNA-activated protein kinase. Another ribozyme specifically inhibited long terminal repeat transactivation, while two additional ones blocked a step that can be bypassed by vesicular stomatitis virus G-protein pseudotyping. The function of Ku80 in HIV replication and its mechanism of action were further confirmed using short interfering RNA. Identification of the gene targets of these and other selected ribozymes may reveal novel therapeutic targets for combating HIV infection.
Coexpression of Hepatitis C Virus E1 and E2 Chimeric Envelope Glycoproteins Displays Separable Ligand Sensitivity and Increases Pseudotype Infectious Titer
Authors: Meyer Keith , Beyene Aster , Bowlin Terry L. , Basu Arnab , Ray Ranjit
Published: November 2004

We have previously reported that a pseudotype virus generated by reconstitution of hepatitis C virus (HCV) chimeric envelope glycoprotein E1-G or E2-G on the surface of a temperature-sensitive mutant of vesicular stomatitis virus (VSVts045) interacts independently with mammalian cells to initiate infection. Here, we examined whether coexpression of both of the envelope glycoproteins on pseudotype particles would augment virus infectivity and/or alter the functional properties of the individual subunits. Stable transfectants of baby hamster kidney (BHK) epithelial cells expressing either one or both of the chimeric envelope glycoproteins of HCV on the cell surface were generated. The infectious titer of the VSV pseudotype, derived from a stable cell line incorporating both of the chimeric glycoproteins of HCV, was ∼4- to 5-fold higher than that of a pseudotype bearing E1-G alone or ∼25- to 30-fold higher than that of E2-G alone when assayed with a number of mammalian cell lines. Further studies suggested that that the E1-G/E2-G or E2-G pseudotype was more sensitive to the inhibitory effect of heparin than the E1-G pseudotype. Treatment of the E1-G/E2-G pseudotype with a negatively charged sulfated sialyl lipid (NMSO3) displayed a ∼4-fold-higher sensitivity to neutralization than pseudotypes with either of the two individual glycoproteins. In contrast, VSVts045, used as a backbone for the generation of pseudotypes, displayed at least 20-fold-higher sensitivity to NMSO3-mediated inhibition of virus plaque formation. The effect of low-density lipoprotein on the E1-G pseudotype was greater than that apparent for the E1-G/E2-G pseudotype. The treatment of cells with monoclonal antibodies to CD81 displayed an inhibitory effect upon the pseudotype with E1-G/E2-G or with E2-G alone. Taken together, our results indicate that the HCV E1 and E2 glycoproteins have separable functional properties and that the presence of these two envelope glycoproteins on VSV/HCV pseudotype particles increases infectious titer.
Improved Efficiency of a
Salmonella
-Based Vaccine against Human Papillomavirus Type 16 Virus-Like Particles Achieved by Using a Codon-Optimized Version of L1
Authors: Baud David , Ponci Françoise , Bobst Martine , De Grandi Pierre , Nardelli-Haefliger Denise
Published: November 2004

Cervical cancer results from cervical infection by human papillomaviruses (HPVs), especially HPV16. An effective vaccine against these HPVs is expected to have a dramatic impact on the incidence of this cancer and its precursor lesions. The leading candidate, a subunit prophylactic HPV virus-like particle (VLP) vaccine, can protect women from HPV infection. An alternative improved vaccine that avoids parenteral injection, that is efficient with a single dose, and that induces mucosal immunity might greatly facilitate vaccine implementation in different settings. In this study, we have constructed a new generation of recombinant
Salmonella
organisms that assemble HPV16 VLPs and induce high titers of neutralizing antibodies in mice after a single nasal or oral immunization with live bacteria. This was achieved through the expression of a HPV16 L1 capsid gene whose codon usage was optimized to fit with the most frequently used codons in
Salmonella
. Interestingly, the high immunogenicity of the new recombinant bacteria did not correlate with an increased expression of L1 VLPs but with a greater stability of the L1-expressing plasmid in vitro and in vivo in absence of antibiotic selection. Anti-HPV16 humoral and neutralizing responses were also observed with different
Salmonella enterica
serovar Typhimurium strains whose attenuating deletions have already been shown to be safe after oral vaccination of humans. Thus, our findings are a promising improvement toward a vaccine strain that could be tested in human volunteers.
Comparison of the Transcription Profile of Simian Parvovirus with That of the Human Erythrovirus B19 Reveals a Number of Unique Features
Authors: Liu Zhengwen , Qiu Jianming , Cheng Fang , Chu Yonglie , Yoto Yuko , O'Sullivan M. Gerard , Brown Kevin E. , Pintel David J.
Published: November 2004

Simian parvovirus (SPV) is a member of the genus
Erythrovirus
and is closely related to the human parvovirus B19. Natural and experimental infection of monkeys with SPV resembles B19 infection of human. We report a detailed characterization of the viral RNAs and proteins generated following transfection of cloned SPV into COS cells and SPV infection of the human erythroid progenitor line UT-7/Epo-S1. SPV and B19 are 50% identical at the nucleotide level, and although their basic transcription and protein expression profiles were generally similar, there were also significant differences. SPV pre-mRNAs contain three introns, compared to two found for B19: an additional intron was found within the capsid-coding region. RNAs in which this intron was spliced were abundant and encoded the SPV 14-kDa protein (analogous to the B19 11-kDa protein), which initiated at an AUG in the exon preceding the third intron. Unlike B19, SPV RNAs were also spliced between the donor of the first intron and the acceptor of the second intron. The third intron was additionally spliced from a portion of these molecules; these mRNAs encoded the 14-kDa protein. A portion was not spliced further and encoded VP2. Like B19, SPV has a polyadenylation signal [AAUAAA (pA)p] in the middle of the genome, which directed efficient polyadenylation of both spliced and unspliced mRNAs (encoding a putative 10-kDa protein, analogous to the B19 7.5-kDa protein, and SPV NS1, respectively). The 14-kDa protein was localized to both in the nucleus and cytoplasm.
Interferon Regulatory Factor 7 Is Associated with Epstein-Barr Virus-Transformed Central Nervous System Lymphoma and Has Oncogenic Properties
Authors: Zhang Luwen , Zhang Jun , Lambert Que , Der Channing J. , Del Valle Luis , Miklossy Judith , Khalili Kamel , Zhou You , Pagano Joseph S.
Published: November 2004

Interferon regulatory factor 7 (IRF-7) is implicated in the regulation of Epstein-Barr virus (EBV) latency. EBV transforms primary B cells, and the major EBV oncoprotein, latent membrane protein 1 (LMP-1), is required for the process. LMP-1 both induces the expression of IRF-7 and activates the IRF-7 protein by phosphorylation and nuclear translocation. Here we report that the expression of IRF-7 is increased in EBV-immortalized B lymphocytes compared with that in primary B cells. IRF-7 was phosphorylated and predominantly localized in the nucleus in the immortalized cells. The expression of IRF-7 was detected in 19 of 27 specimens of primary lymphomas of the human central nervous system by immunohistochemical analysis. The association between LMP-1 and IRF-7 was statistically highly significant for these specimens. An appreciable amount of the IRF-7 expressed in lymphoma cells was localized in the nucleus. Furthermore, IRF-7 promoted the anchorage-independent growth of NIH 3T3 cells. LMP-1 and IRF-7 showed additive effects on the growth transformation of NIH 3T3 cells. IRF-7-expressing NIH 3T3 cells formed tumors in athymic mice. Thus, IRF-7 has oncogenic properties and, along with LMP-1, may mediate or potentiate the EBV transformation process in the pathogenesis of EBV-associated lymphomas.
Inhibition of Human Immunodeficiency Virus Replication by a Dual CCR5/CXCR4 Antagonist
Authors: Princen Katrien , Hatse Sigrid , Vermeire Kurt , Aquaro Stefano , De Clercq Erik , Gerlach Lars-Ole , Rosenkilde Mette , Schwartz Thue W. , Skerlj Renato , Bridger Gary , Schols Dominique
Published: November 2004

Here we report that the
N
-pyridinylmethyl cyclam analog AMD3451 has antiviral activity against a wide variety of R5, R5/X4, and X4 strains of human immunodeficiency virus type 1 (HIV-1) and HIV-2 (50% inhibitory concentration [IC
50
] ranging from 1.2 to 26.5 μM) in various T-cell lines, CCR5- or CXCR4-transfected cells, peripheral blood mononuclear cells (PBMCs), and monocytes/macrophages. AMD3451 also inhibited R5, R5/X4, and X4 HIV-1 primary clinical isolates in PBMCs (IC
50
, 1.8 to 7.3 μM). A PCR-based viral entry assay revealed that AMD3451 blocks R5 and X4 HIV-1 infection at the virus entry stage. AMD3451 dose-dependently inhibited the intracellular Ca
2+
signaling induced by the CXCR4 ligand CXCL12 in T-lymphocytic cells and in CXCR4-transfected cells, as well as the Ca
2+
flux induced by the CCR5 ligands CCL5, CCL3, and CCL4 in CCR5-transfected cells. The compound did not interfere with chemokine-induced Ca
2+
signaling through CCR1, CCR2, CCR3, CCR4, CCR6, CCR9, or CXCR3 and did not induce intracellular Ca
2+
signaling by itself at concentrations up to 400 μM. In freshly isolated monocytes, AMD3451 inhibited the Ca
2+
flux induced by CXCL12 and CCL4 but not that induced by CCL2, CCL3, CCL5, and CCL7. The CXCL12- and CCL3-induced chemotaxis was also dose-dependently inhibited by AMD3451. Furthermore, AMD3451 inhibited CXCL12- and CCL3L1-induced endocytosis in CXCR4- and CCR5-transfected cells. AMD3451, in contrast to the specific CXCR4 antagonist AMD3100, did not inhibit but enhanced the binding of several anti-CXCR4 monoclonal antibodies (such as clone 12G5) at the cell surface, pointing to a different interaction with CXCR4. AMD3451 is the first low-molecular-weight anti-HIV agent with selective HIV coreceptor, CCR5 and CXCR4, interaction.
Induction of Epstein-Barr Virus Latent Membrane Protein 1 by a Lytic Transactivator Rta
Authors: Chang Yao , Lee Heng-Huan , Chang Shih-Shin , Hsu Tsuey-Ying , Wang Pei-Wen , Chang Yu-Sun , Takada Kenzo , Tsai Ching-Hwa
Published: November 2004

Latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) is a transforming protein that affects multiple cell signaling pathways and contributes to EBV-associated oncogenesis. LMP1 can be expressed in some states of EBV latency, and significant induction of full-length LMP1 is also observed frequently during virus reactivation into the lytic cycle. It is still unknown how LMP1 expression is regulated during the lytic stage and whether any EBV lytic protein is involved in the induction of LMP1. In this study, we first identified that LMP1 expression is associated with the spontaneous virus reactivation in EBV-infected 293 cells and that its expression is a downstream event of the lytic cycle. We further found that LMP1 can be induced by ectopic expression of Rta, an EBV immediate-early lytic protein. The Rta-mediated LMP1 induction is independent of another immediate-early protein, Zta. Northern blotting and reverse transcription-PCR analysis revealed that Rta upregulates LMP1 at the RNA level. Reporter gene assays further demonstrated that Rta activates both the proximal and distal promoters of the LMP1 gene in EBV-negative cells. Both the amino and carboxyl termini of the Rta protein are required for the induction of LMP1. In addition, Rta transactivates LMP1 not only in epithelial cells but also in B-lymphoid cells. This study reveals a new mechanism to upregulate LMP1 expression, expanding the knowledge of LMP1 regulation in the EBV life cycle. Considering an equivalent case of Kaposi's sarcoma-associated herpesvirus, induction of a transforming membrane protein by a key lytic transactivator during virus reactivation is likely to be a conserved event for gammaherpesviruses.