bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the N Gene Hypersensitive Response Induced by a Fluorescently Tagged Tobacco Mosaic Virus
Authors: Wright Kathryn M. , Duncan George H. , Pradel Katja S. , Carr Fiona , Wood Susannah , Oparka Karl J. , Cruz Simon Santa
Published: July 2002

The hypersensitive response (HR) triggered on Nicotiana edwardsonii by tobacco mosaic virus was studied using a modified viral genome that directed expression of the green fluorescent protein. Inoculated plants were initially incubated at 32°C to inhibit the N gene-mediated HR. Transfer to 20°C initiated the HR, and fluorescent infection foci were monitored for early HR-associated events. Membrane damage, which preceded visible cell collapse by more than 3 h, was accompanied by a transient restriction of the xylem within infection sites. Following cell collapse and the rapid desiccation of tissue undergoing the HR, isolated, infected cells were detected at the margin of necrotic lesions. These virus-infected cells were able to reinitiate infection on transfer to 32°C, however, if maintained at 20°C they eventually died. The results indicate that the tobacco mosaic virus-induced HR is a two-phase process with an early stage culminating in rapid cell collapse and tissue desiccation followed by a more extended period during which the remaining infected cells are eliminated.
Apparent Absence of a Redox Requirement for Blue Light Activation of Pump Current in Broad Bean Guard Cells
Authors: Taylor Alison R. , Assmann Sarah M.
Published: July 2002

In guard cells, membrane hyperpolarization in response to a blue light (BL) stimulus is achieved by the activation of a plasma membrane H+-ATPase. Using the patch clamp technique on broad bean (Vicia faba) guard cells we demonstrate that both steady-state- and BL-induced pump currents require ATP and are blocked by vanadate perfused into the guard cell during patch clamp recording. Background-pump current and BL-activated currents are voltage independent over a wide range of membrane potentials. During BL-activated responses significant hyperpolarization is achieved that is sufficient to promote K+ uptake. BL activation of pump current becomes desensitized by three or four pulses of 30 s × 100 μmol m−2 s−1 BL. This desensitization is not a result of pump inhibition as maximal responses to fusicoccin are observed after full BL desensitization. BL treatments prior to whole cell recording show that BL desensitization is not due to washout of a secondary messenger by whole cell perfusion, but appears to be an important feature of the BL-stimulated pump response. We found no evidence for an electrogenic BL-stimulated redox chain in the plasma membrane of guard cells as no steady-state- or BL-activated currents are detected with NADH or NADPH added to the cytosol in the absence of ATP. Steady-state- nor BL-activated currents are affected by the inclusion along with ATP of 1 mm NADH in the pipette under saturating red light or by including NADPH in the pipette under darkness or saturating red light. These data suggest that reduced products of photosynthesis do not significantly modulate plasma membrane pump currents and are unlikely to be critical regulators in BL-stimulation of the plasma membrane H+-ATPase in guard cells.
The Light Sensitivity of ATP Synthase Mutants ofChlamydomonas reinhardtii
Authors: Majeran Wojciech , Olive Jacqueline , Drapier Dominique , Vallon Olivier , Wollman Francis-André
Published: July 2002

Chlamydomonas reinhardtii mutants defective in the chloroplast ATP synthase are highly sensitive to light. The ac46 mutant is affected in the MDH1 gene, required for production or stability of the monocistronic atpH mRNA encoding CFO-III. In this and other ATP synthase mutants, we show that short-term exposure to moderate light intensities—a few minutes—induces an inhibition of electron transfer after the primary quinone acceptor of photosystem II (PSII), whereas longer exposure—several hours—leads to a progressive loss of PSII cores. An extensive swelling of thylakoids accompanies the initial inhibition of electron flow. Thylakoids deflate as PSII cores are lost. The slow process of PSII degradation involves the participation of ClpP, a chloroplast-encoded peptidase that is part of a major stromal protease Clp. In the light of the above findings, we discuss the photosensitivity of ATP synthase mutants with respect to the regular photoinhibition process that affects photosynthetic competent strains at much higher light intensities.
The Enhancement of Phototropin-Induced Phototropic Curvature in Arabidopsis Occurs via a Photoreversible Phytochrome A-Dependent Modulation of Auxin Responsiveness
Authors: Stowe-Evans Emily L. , Luesse Darron R. , Liscum Emmanuel
Published: July 2002

The induction of phototropism in etiolated (dark-grown) seedlings exposed to an unidirectional pulse or extended irradiation with low fluence rate blue light (BL) requires the action of the phototropin (nph1) BL receptor. Although cryptochromes and phytochromes are not required for phototropic induction, these photoreceptors do modulate the magnitude of curvature resulting from phototropin activation. Modulatory increases in the magnitude of phototropic curvature have been termed “enhancement.” Here, we show that phototropic enhancement is primarily a phytochrome A (phyA)-dependent red/far-red-reversible low fluence response. This phyA-dependent response is genetically separable from the basal phototropin-dependent response, as demonstrated by its retention under extended irradiation conditions in the nph4 mutant background, which normally lacks the basal BL-induced response. It is interesting that thenph4 mutants fail to exhibit the basal phototropin-dependent and phyA-dependent enhancement responses under limiting light conditions. Given that NPH4 encodes a transcriptional activator, auxin response factor 7 (ARF7), we hypothesize that the ultimate target(s) of phyA action during the phototropic enhancement response is a rate-limiting ARF-containing transcriptional complex in which the constituent ARFs can vary in identity or activity depending upon the irradiation condition.
Cell Cycle Regulation of Cyclin-Dependent Kinases in Tobacco Cultivar Bright Yellow-2 Cells
Authors: Sorrell David A. , Menges Margit , Healy J.M. Sandra , Deveaux Yves , Amano Chinatsu , Su Ya , Nakagami Hirofumi , Shinmyo Atsuhiko , Doonan John H. , Sekine Masami , Murray James A.H.
Published: July 2002

Plants possess two major classes of cyclin-dependent kinases (CDK) with cyclin-binding motifs PSTAIRE (CDK-a) and PPTA/TLRE (CDK-b). Tobacco (Nicotiana tabacum L. cv Bright Yellow-2) cells are the most highly synchronizable plant culture, but no detailed analysis of CDK activities has been reported in this system. Here we describe isolation of new PPTALRE CDKs (Nicta;CdkB1) from Bright Yellow-2 cells and present detailed analysis of the mRNA, protein and kinase activity levels of CdkB1, and the PSTAIRE CDKA during the growth and cell cycles. CdkA andCdkB1 transcripts are more abundant in exponential than in stationary phase cells, but the two genes show strikingly different regulation during the cell cycle. CdkA mRNA and protein accumulate during G1 in cells re-entering the cell cycle, and immunoprecipitated histone H1 kinase activity increases at the G1/S boundary. Aphidicolin synchronized cells show the highest CDKA-associated histone H1 kinase activity during S-G2 phases, althoughCdkA mRNA and protein levels are not significantly regulated. In contrast, CdkB1 transcripts are present at very low levels until S phase and CDKB1 protein and kinase activity is almost undetectable in G1. CdkB1 mRNA accumulates through S until M phase and its associated kinase activity peaks at the G2/M boundary, confirming that transcription of PPTALRE CDKs is cell cycle regulated. We suggest that CDKA kinase activity likely plays roles at the G1/S phase boundary, during S phase, and at the G2/M phase transition, and that CDKB1 kinase activity is present only at G2/M.
Cytokinin Overproducing ove Mutants ofPhyscomitrella patens Show Increased Riboside to Base Conversion
Authors: Schulz Peter A. , Hofmann Angelika H. , Russo Vincenzo E.A. , Hartmann Elmar , Laloue Michel , von Schwartzenberg Klaus
Published: July 2002

Ove mutants in the moss Physcomitrella patens can arise from different recessive mutations. These mutants display a much larger number of buds than the wild type (wt) due to a dramatic overproduction of cytokinins (Cks), which are released into the culture medium (T.L. Wang, R. Horgan, D.J. Cove [1981] Plant Physiol 68: 735–738). The amounts of isopentenyladenine (iP) and isopentenyladenosine ([9R]iP) produced by chloronema of different ove mutants were measured. Levels of the major Ck iP in the culture medium of the mutantsoveA78, oveA201, oveC200, and oveB300 (cultured at 21°C) were 4-fold (oveA78) to 22-fold (oveB300) higher than for the wt. A new temperature-sensitive ove strainoveST25, which exhibits a strong ovephenotype at 25°C, was also studied. It produced about 260 times more iP than the thiamine auxotrophic wt from which it was derived. To contribute to the physiological understanding of Ck overproduction, in vivo labeling experiments with 3H-[9R]iP were performed. In all ove mutants analyzed, the rate of3H-[9R]iP conversion to 3H-iP was higher as compared with the wt. In oveST25, the 3-fold increased riboside to base conversion was temperature inducible and correlated with the iP production. Analysis of Ck catabolism revealed no major differences between ove mutants and wt, thus indicating that ove mutants are unlikely to be degradation mutants. The data suggest that in ove mutants the increased riboside to base conversion is part of a generally up-regulated Ck biosynthetic pathway and may play an important role for the enhanced release of iP into the medium.
Galvanic corrosion interactions of zinc and SS.304 in the tropical marine atmosphere of Mandapam
Authors: Subramanian G. , Palraj S. , Balasubramanian T.M.
Published: July 2002

The galvanic corrosion interactions of zinc and SS.304 have been studied in a tropical marine environment over a period of 427 days, under different area ratios. The galvanic interaction of zinc and SS.304 are highlighted in terms of the corrosion rate of zinc or SS.304 resulting from galvanic coupling, and the susceptibility of zinc to pitting due to galvanic corrosion. The galvanic potential and galvanic current of the system are monitored. The corrosion products at the interface of the bimetallic contacts are analysed with XRD technique and the pitting/grooving on zinc resulting from galvanic corrosion is measured using a high resolution microscope. The weathering parameters and environmental pollutants are monitored to give an insight into the possible means of favouring the galvanic interactions. The results of the study are discussed in the light of the above factors towards predicting a mechanism for the galvanic interactions of zinc and SS.304.
Moving away from a typical Mediterranean diet: the case of Spain
Authors: Gracia Azucena , Miguel Albisu Luis
Published: July 2002

In the 1960s, the Spanish diet was a typical example of the Mediterranean diet. However, in the 1990s, Spanish consumers have moved away from that pattern. This has been the result of many different changes over that period of time. It is important to know how a Mediterranean country moves from a considered healthy diet to another which is not so and the reasons behind that change. There might be a number of policy implications to reinforce food consumption habits which are not properly taken into consideration when a country goes through economic development. Nowadays, public institutions in Spain are concerned about changing diets. They provide information and encourage the appropriate education to achieve those aims. Among other things, they try to promote typical regional products of high quality as well as to avoid unhealthy food habits, by providing nutritional educational programmes at schools, jointly with other policies.
Organisational learning in small learning organisations: an empirical overview
Authors: Matlay Harry
Published: July 2002

Much has been written, in recent years, on the subject of learning organisations and knowledge‐based businesses. Most research in this area, however, focuses upon large businesses. In this type of firm, it appears the concepts of “organisational learning” and “learning organisation” can be, and often are, used interchangeably to describe learning‐based individual and collective development. Until recently, issues relating to organisational learning in small businesses were mostly ignored or marginalised. This paper sets out to redress the balance. It reports a study of organisational learning in the small business sector of the UK economy. Research data, collected over the 1996‐1998 period, through telephone surveys, in‐depth interviews and case studies, were analysed through quantitative and qualitative methods. The results indicate that although learning can occur in the majority of small businesses in the sample, only a minority of these manage new knowledge strategically to sustain and advance their competitive advantage.
Delivering the promise: developing new graduates
Authors: Graham Colin , McKenzie Alasdair
Published: July 2002

The second of two articles, reports the findings of a qualitative
research project investigating good practice in recruiting, training and
retaining new graduates. The research took place in 15 UK public‐ and
private‐sector organizations including the NHS in Scotland, KPMG Peat
Marwick, GKN, Sema and Girobank. Examines how to get the most from the
opportunity for intensive development. Develops ideas on how employers
can successfully and quickly develop new graduates into effective
business people, adding value to the organization and its customers.
Focuses on the important role of the direct manager in coaching and
bringing the new graduate up to speed. Also highlights how the group of
new graduates can be used to build a supportive peer group and a network
of contacts across the organization to help get things done.
Building a business school in China: the case of the China Europe International Business School (CEIBS)
Authors: Southworth David B.
Published: July 2002

Under the Chinese planned economy, there was no need for trained managers. Consequently, a huge skills shortage has arisen, focused in areas such as financial management, marketing and HRM. China’s Education Vice Minister estimates a need for 2.7m trained managers to meet the competitive challenges facing the country. In China’s universities, however, the requisite skills and experience are largely absent. Yet, imported training lacks the unique cultural context and suffers translation difficulties while the students lack the appropriate conceptual frameworks to interpret their new knowledge. Additionally, foreign programmes are forced to deliver within the context of a local university system which is usually inappropriate. The China Europe International Business School (CEIBS) was set up to overcome these constraints and to establish a model for management education in China. This paper describes the issues and challenges in the establishment of the school, the implications for China and the achievements after the first five years of the school.
Pouring the coffee at interviews?
Authors: Lupton Ben
Published: July 2002

Examines the role of the personnel function in the selection of doctors. Reveals a “clerk of works” role, marginal to the decision‐making process. Considers the implications of such a role for effective and fair selection practice. Develops a model of “weak” personnel management which illustrates the factors limiting the power and influence of personnel specialists, both in recruitment and in other areas. Considers the impact of an interface with professional staff on the nature of personnel roles.
Strategic HRM: evidence from the Irish food industry
Authors: Bin Othman Rozhan
Published: July 2002

One of the main features of human resource management (HRM) is the emphasis on aligning the organization’s employee management practice with its strategy. It is argued that the strategy pursued by an organization needs to be supported by a compatible form of HRM practices. Each strategy has to be supported by a specific form of HRM practice. The attainment of a strategy‐HRM fit is crucial in ensuring the effective utilization of the organization’s human resources engendered by this fit which are supposed to lead to improved performance. In spite of the relative popularity of the HRM concept and the strategy‐HRM fit thesis, there is little empirical evidence to show its presence in organizational practice. Seeks to examine this relationship in the Irish food industry. Finds that there was no evidence to support the proposition that strategy is the imperative in shaping HRM practice. The examination of the data showed that when other contingencies were taken into consideration the initial findings, showing an association between HRM practice and a competitive strategy, no longer holds. Instead, contingencies such as the presence of a HRM department and employment size are more important predictors of HRM practice.
Multi‐axis force and torque sensing
Authors: Perry Dwayne M.
Published: July 2002

Discusses the measurement of complex force and torque loads with strain‐gauge based sensors for both industrial and research environments. Cites applications that will find this type of load sensing invaluable. Focuses on silicon strain‐gauge based sensors that can withstand high overloads without damage.
Oxford Sensor Technology ‐ a story of perseverance
Authors: Braggins Don
Published: July 2002

Outlines the development over a period of 27 years of a novel sensor that uses the off‐axis rotation of a lens to provide a circular scan of distance data. Applications include weld line tracking, waterjet cutting and many others requiring the measurement of curved and angled surfaces.
A value‐creating model for effective policy services
Authors: Behm Allan , Bennington Lynne , Cummane James
Published: July 2002

Policy services have generally escaped performance evaluation techniques. Traditionally, the evaluation of the quality of policy services has been internally driven, and has tended to rely on definitions and process practices determined by the service provider rather than customer definitions of value. In this study, customers of policy services (ministers, ex‐ministers, department secretaries and key advisers) were asked what the ideal characteristics of policy services were and what would create value. On the basis of customer values, an integrated four level model of policy service provision was developed. This model potentially provides guidance for the development and evaluation of policy services and should lead to greater customer satisfaction.
Professional facilities management in public sector organisations
Authors: Clark Liz , Rees David
Published: July 2002

The authors refer to their research into the role of facilities management (FM) within the National Health Service and local government in England and Wales. They compare the levels of FM awareness within these public bodies, the ability of FM managers to influence the decision‐making process, the relationship between these factors and the delivery of effective facilities management services and the relative importance given to FM in recent Government guidelines on best value in these two public services. Based on the findings of five research projects the authors have conducted in both sectors it illustrates how FM is not just a business opportunity but a rapidly expanding function that is gaining status as an important profession that warrants a high status in the strategic make‐up of both NHS Trusts and local government authorities.
Facilities management development in Hong Kong
Authors: Lomas D.W.
Published: July 2002

The area of facilities management (FM) has grown significantly in recent years. The principles of FM were initially developed in the United States and then exported world‐wide. The UK and parts of Europe are beginning to reap rewards in terms of better industrial practices and efficiency. These have been made possible by the use of benchmarking and the identification of best practices; both within a particular industry and also outside them. FM has only recently been adopted in Asia. This paper will analyse the development of practice, research and education, particularly in Hong Kong. Comparisons will also be drawn between the Asian examples and the UK.
ISO 9000: is the real estate sector any different?
Authors: Buttle Francis A. , Ross Jayne Michael
Published: July 2002

This paper utilises the findings from the largest‐ever national, omni‐sectoral survey into the impacts of ISO 9000 on UK business and specifically examines the real estate sector, contrasting the findings with those found for the larger universe. Analysis across all sectors shows that while companies’ expectations of ISO 9000 are not met in full, they are generally satisfied with the contribution made to their organisation. While the real estate sector differs in points of detail from the larger universe, statistical analysis indicates that there are no significant differences.
The reconstruction of boundary contours and surfaces in arbitrary unstructured triangular and tetrahedral grids
Authors: Weatherill N.P.
Published: July 2002

In an arbitrary assembly of triangles or tetrahedra there is often a requirement to recover or construct edges or triangles which are formed by the connections between nodes. Such is the case in computational methods where grids of triangles or tetrahedra must conform to prespecified boundaries. Discusses general techniques which can be applied to recover edges and triangles within unstructured assemblies of triangles and tetrahedra. The methods described involve the intersection of the required edges and triangles with other nodes, edges, triangles and tetrahedra and then locally performing transformations of the element connectivities. The method is applied to the recovery of fixed boundary triangles for finite element meshes and to the construction of multidomains within unstructured grids. Several applications of the method are given to real practical problems.
“Survivor syndrome” – a management myth?
Authors: Baruch Yehuda , Hind Patricia
Published: July 2002

Research has indicated that employees who remain within an organization after significant downsizing or delayering will experience adverse effects as profoundly as those who have left. This phenomenon has been labelled the “survivor syndrome”. This article first of all examines data from an employee opinion survey in a large UK financial institution following sequential and significant restructuring. The empirical findings contradict some propositions suggested in former studies in that evidence of “survivor syndrome” was not apparent. Second, the article explores possible reasons for the non‐existence of the syndrome. The findings are discussed in the light of the process of the redundancy programme.
A unique electroplating tin chemistry
Authors: Zhang Yun , Abys Joseph A.
Published: July 2002

A novel tin electrodeposition chemistry and process has been developed at Bell Laboratories, Lucent Technologies, New Jersey, USA. This process produces smooth, satin bright tin deposits which have stable, large grain structures. The deposits contain very low organic content and, as a consequence, exhibit excellent ductility, solderability and reflowability. The chemistry is capable of operating at elevated temperatures over a wide range of current densities, and is, thus, applicable to rack, barrel and reel‐to‐reel operations. All chemical components, including breakdown products are fully analyzable with conventional analytical methods. Extensive bath life studies show that the deposit appearance and material properties, including grain structures, are stable in relation to the age of the electroplating chemistry. In addition, the grain refiners used are highly stable, and have few breakdown products as the chemistry ages. All these features imply a robust process which has been confirmed in various manufacturing environments. This tin electroplating process has been utilized in plating coatings for connectors, solder bumps, PWBs and components for semiconductor applications.
Transference of skills between sports and business
Authors: Liu Jonathan , Srivastava Ashok , Seng Woo Hong
Published: July 2002

This paper presents the findings of a literature review and survey conducted on sport sponsorship in the UK. The paper seeks to establish relevant material published that addresses the issue of the transferability of techniques and skills from sports to business. The findings of the literature review highlighted the close relationship between the two mediums. The results of the sponsorship questionnaire showed evidence of the transference of mutually beneficial skills between the organisations offering the assistance, and the sporting organisation receiving the funding. The survey indicated that a majority of sports sponsoring organisations offered more than just monetary assistance to their beneficiaries. Sponsors also assisted with the management of specific events, and operated the complicated software and computer equipment required for the smooth running of the sporting activity. These organisations supplied the sports with key personnel, and highly skilled staff who were experts in their respective fields in marketing, public relations, corporate hospitality, and management.
Non‐similar solutions for heat and mass transfer by hydro‐magnetic mixed convection flow over a plate in porous media with surface suction or injection
Authors: Chamkha Ali J.
Published: July 2002

The problem of steady, laminar, heat and mass transfer by mixed convection from a semi‐infinite, isothermal, vertical and permeable plate embedded in a uniform porous medium in the presence of temperature‐dependent heat source or sink and magnetic field effects is considered. A mixed convection parameter for the entire range of free‐forced‐mixed convection is employed and non‐similar equations are obtained. These equations are solved numerically by an efficient implicit, iterative, finite‐difference scheme. The obtained results are checked against previously published work on special cases of the problem and are found to be in good agreement. Useful correlations for the local Nusselt number are obtained for various physical parameters. A parametric study illustrating the influence of the magnetic field, porous medium inertia effects, heat generation or absorption, concentration to thermal buoyancy ratio, and the Lewis number on the fluid velocity, temperature and concentration as well as the Nusselt and the Sherwood numbers is conducted. The obtained results are shown graphically and the physical aspects of the problem are discussed.
Community vulnerability to volcanic hazard consequences
Authors: Miller Marian , Paton Douglas , Johnston David
Published: July 2002

This paper explores some psychological aspects of community vulnerability following the 1995 and 1996 eruptions at Ruapehu volcano, New Zealand. A model comprising three psychological factors (sense of community, coping style and self‐efficacy) is used to investigate this issue. The results suggest that self‐efficacy and problem‐focused coping reduce vulnerability and that this model has a role to play in identifying vulnerable communities. The differential implications of physical and economic hazard consequences for community vulnerability were also examined. Data is presented that reinforces the view that the salience of volcanic hazard consequences is a result of their implications for community functions and resources. The implications for mitigation, threat communication and the development of resilient communities are discussed.
Beyond service quality dimensions in higher education and towards a service contract
Authors: Rowley Jennifer
Published: July 2002

Suggests that an essential prerequisite to the design of instruments for measuring quality in higher education is an appreciation of the complexities associated with the nature of quality measurement and enhancement in higher education. The central role of perceptions and expectations and the complexity of the contributions of the different types of customer are crucial. Explores the following issues: what quality is, which quality is important, and the ownership of quality. Identifies aspects of the educational experience that differentiate education from other service experiences as including exclusivity of access; the role of the customer in the process and the longitudinal nature of the educational experience. Proposes the concept of a service contract, to be established in the first instance with students, as one approach to managing expectations and perceptions in order to generate more positive quality judgements.
Application of team‐based 360° feedback systems
Authors: Hurley Simon
Published: July 2002

An increasingly important performance measurement tool, especially in the area of teams, is 360° feedback. This paper discusses the theories behind the system, and provides an in‐depth review of the techniques of implementing 360° feedback in an organization. Steps for implementation include selection of raters, questionnaire construction, feedback, presentation, and follow‐up. Additional considerations such as rater responsibility, cost, organizational change and support, benefits, and dangers of abuse or mis‐usage of the system are addressed. Special considerations are discussed for using the system in team settings and how the system can be built‐in to a developing team system or adapted for use in an existing one. More research is currently needed in areas such as quality of samples, process information, training effectiveness, and sustaining the process.
Pros and cons of thermoplastic and thermoset polymer adhesives in microelectronic assembly applications
Authors: Gilleo Ken , Ongley Peter
Published: July 2002

Reviews the traditional use of thermoset (epoxy) adhesives for various bonding applications and highlights some limitations in today’s microelectronics arena. In particular, concerns for thermal and stress management associated with large area silicon bonded to a wide variety of substrate materials has led to an increasing interest in thermoplastic adhesive technology. Thermoplastics are not always the best solution for every application. This paper sets out to address the “pros and cons” of each polymer technology for different microelectronic applications taking into account some of the key physical properties such as Tg, TCE and modulus. In addition, practical issues such as handling, storage and processing are considered in detail.
Structural and thermodynamic analysis of the binding of solvent at internal sites in T4 lysozyme
Authors: Xu Jian , Baase Walter A. , Quillin Michael L. , Baldwin Enoch P. , Matthews Brian W.
Published: July 2002

To investigate the structural and thermodynamic basis of the binding of solvent at internal sites within proteins a number of mutations were constructed in T4 lysozyme. Some of these were designed to introduce new solvent‐binding sites. Others were intended to displace solvent from preexisting sites. In one case Val‐149 was replaced with alanine, serine, cysteine, threonine, isoleucine, and glycine. Crystallographic analysis shows that, with the exception of isoleucine, each of these substitutions results in the binding of solvent at a polar site that is sterically blocked in the wild‐type enzyme. Mutations designed to perturb or displace a solvent molecule present in the native enzyme included the replacement of Thr‐152 with alanine, serine, cysteine, valine, and isoleucine. Although the solvent molecule was moved in some cases by up to 1.7Å, in no case was it completely removed from the folded protein. The results suggest that hydrogen bonds from the protein to bound solvent are energy neutral. The binding of solvent to internal sites within proteins also appears to be energy neutral except insofar as the bound solvent may prevent a loss of energy due to potential hydrogen bonding groups that would otherwise be unsatisfied. The introduction of a solvent‐binding site appears to require not only a cavity to accommodate the water molecule but also the presence of polar groups to help satisfy its hydrogen‐bonding potential. It may be easier to design a site to accommodate two or more water molecules rather than one as the solvent molecules can then hydrogen‐bond to each other. For similar reasons it is often difficult to design a point mutation that will displace a single solvent molecule from the core of a protein.
Structural features of interferon‐γ aggregation revealed by hydrogen exchange
Authors: Tobler Scott A. , Fernandez Erik J.
Published: July 2002

Using hydrogen‐deuterium exchange (HX) and electrospray ionization mass spectrometry, we have investigated the stability and structural changes of recombinant human interferon‐γ (IFN‐γ) during aggregation induced by guanidine hydrochloride (GdnHCl) and potassium thiocyanate. First, HX labeling was initiated after the amorphous aggregates were formed to probe the tertiary structure of the aggregated state. Second, labeling was performed at low protein concentrations to assess stability under aggregation prone conditions. In 1 M GdnHCl, the stability of IFN‐γ was greatly reduced and much less protection from HX in solution was observed. Exchange under these conditions was slower in helix C than in the rest of the protein. Aggregates formed in 1 M GdnHCl showed a HX pattern consistent with a partially unfolded state with an intact helix C. Although aggregates formed in 0.3 M KSCN exhibited a HX pattern similar to those formed in GdnHCl, the solution phase HX pattern in 0.3 M KSCN was surprisingly comparable to that of the native state. Varying the aggregation time before performing HX revealed that KSCN first precipitated native protein and then facilitated partial unfolding of the precipitated protein. These results show that helix C, which forms the hydrophobic core of the IFN‐γ dimer, is highly protected from HX under native conditions, is more stable in GdnHCl than the rest of the protein and remains intact in both GdnHCl‐ and KSCN‐induced aggregates. This suggests that native‐state HX patterns may presage regions of the protein susceptible to unfolding during aggregation.
Permanent‐transitory Decomposition in Var Models With Cointegration and Common Cycles
Authors: Hecq Alain , Palm Franz C. , Urbain Jean‐Pierre
Published: July 2002

In this paper we derive permanent‐transitory decompositions of non‐stationary multiple times series generated by (r)nite order Gaussian VAR(p) models with both cointegration and serial correlation common features. We extend existing analyses to the two classes of reduced rank structures discussed in Hecq, Palm and Urbain (1998). Using the corresponding state space representation of cointegrated VAR models in vector error correction form we show how decomposition can be obtained even in the case where the number of common feature and cointegration vectors are not equal to the number of variables. As empirical analysis of US business fluctuations shows the practical relevance of the approach we propose.
Electroconvulsive Therapy and the Fear of Deviance
Authors: Giles James
Published: July 2002

After reaching the verge of obsolescence, electroconvulsive therapy (ECT) is once again on the increase. There remains, however, no sound theoretical basis for its use. By 1948 at least 50 different theories had been proposed to account for the workings of ECT. Today there are numerous more. Further, there is no good evidence for its therapeutic effectiveness. Although some studies show what are claimed to be positive results, others show significant amount of relapse, even with severe depression (the disorder against which ECT is supposed to be most effective), while even other studies show ECT to have little more effect than a placebo. Finally, there is much evidence for ECTs damaging effects, particularly to cognitive functioning like memory, general intelligence level, and perceptual abilities, and quite possibly to brain functioning. Some studies even suggest that the alleged therapeutic effects of ECT are essentially the effects of organic brain damage. The question, then, is why, despite these problems, does ECT continue to be used? ECTs salient features suggest an answer here. These are the features of dehumanization, power, control, punishment, and others, all of which can be traced back to the fear of deviant psychotic behavior.
Ultrastructural basis of synaptic transmission between endbulbs of Held and bushy cells in the rat cochlear nucleus
Authors: Nicol Madeleine J. , Walmsley Bruce
Published: July 2002

Auditory nerve fibres make large excitatory synaptic contacts, the endbulbs of Held, with bushy cells in the anteroventral cochlear nucleus (AVCN). We have used serial‐section electron microscopy to reconstruct seven endbulbs of Held in contact with three different AVCN bushy cells from a 25‐day‐old rat, as a basis for interpreting our previous physiological results at this connection. Four endbulbs of Held contacting the same bushy cell were completely reconstructed. The number of separate synaptic specializations within these endbulbs varied from 85 to 217, with a mean of 155. Detailed measurements were obtained from high magnification segments of four endbulbs contacting three different bushy cells. Large variability was found in the size of synaptic specializations within an individual endbulb. The size of postsynaptic densities (PSDs) varied between endbulbs (mean PSD area 0.03, 0.07, 0.07 and 0.18 μm2; n= 4 endbulbs). The number of morphologically docked vesicles at individual specializations within the same endbulb varied considerably (between 1 and 102). The mean number of morphologically docked vesicles per specialization differed between endbulbs (mean numbers of docked vesicles per specialization = 2.1, 3.7, 5.3, 14.8; n= 4 endbulbs). Despite these large differences, the density of docked vesicles per square micron of PSD was similar between endbulbs (54, 80, 81, 83 docked vesicles per μm2; n= 4 endbulbs). Within an endbulb, a linear relationship was found between the number of docked vesicles and PSD area, and between PSD area and the number of undocked vesicles within 150 nm of the active zone. The ratio of undocked vesicles (< 150 nm) to docked vesicles ranged from 2 to 5 in different endbulbs (n= 4 endbulbs). These structural observations are discussed in relation to the functional properties of synaptic transmission between endbulbs of Held and bushy cells in the AVCN.
Measurement of interstitial lactate during hypoxia‐induced dilatation in isolated pressurised porcine coronary arteries
Authors: Frøbert Ole , O. Mikkelsen Erich , Bagger Jens P. , Gravholt Claus H.
Published: July 2002

Lactate is formed in the coronary arterial wall and in the myocardium as a consequence of ischaemia and infarction. We combined direct measurement of coronary artery diameter and interstitial arterial wall lactate concentration ex vivo in order to ascertain the possible role of lactate in hypoxia‐induced vasodilatation. The wall of porcine coronary arteries, precontracted during an intraluminal pressure of 40 mmHg by addition of prostaglandin F2α, was cannulated using a microdialysis catheter, and exposed to hypoxia for 60 min, followed by 45 min of reoxygenation. The exchange fraction of [14C]lactate over the microdialysis membrane increased from 0.38 ± 0.04 to 0.52 ± 0.05 (P < 0.001) during the study period. Coronary artery diameter increased by 15.5 ± 2.0 % (n= 20) during hypoxia (P < 0.001, compared to normoxic controls) and interstitial lactate concentration rose from 1.07 ± 0.21 to 2.50 ± 0.40 mmol l−1 during hypoxia (P < 0.01) and was unchanged in controls. The increase in coronary artery diameter correlated with the increase in interstitial lactate concentration in the period between 30 and 60 min of hypoxia (r= 0.62; P= 0.02). Dichloroacetate (10−5m), an agent that reduces lactate generation by activating pyruvate dehydrogenase, abolished hypoxia‐induced lactate production, but caused a further increase in coronary arterial diameter (30.2 ± 4.4 %, n= 9; P < 0.001 vs. hypoxia and no dichloroacetate). Under control conditions, the addition of l‐lactate (10−3‐10−2m) increased dose‐dependently coronary arterial diameter by 22.0 ± 4.2 % (n= 5) and interstitial lactate concentration from 0.52 ± 0.04 to 5.70 ± 0.66 mmol l−1 (P < 0.001). There was a correlation between the increase in coronary artery diameter and interstitial lactate concentration (r= 0.60; P= 0.02). The present observations represent the first direct measurements of metabolites by microdialysis in a blood vessel wall. The lactate concentration may affect, but is not essential for, hypoxia‐induced vasodilatation in porcine coronary arteries.
CD59 blocks not only the insertion of C9 into MAC but inhibits ion channel formation by homologous C5b‐8 as well as C5b‐9
Authors: Farkas Imre , Baranyi Lajos , Ishikawa Yasushige , Okada Noriko , Bohata Csaba , Budai Denes , Fukuda Atsuo , Imai Masaki , Okada Hidechika
Published: July 2002

Activation of the complement system on the cell surface results in the insertion of pore forming membrane attack complexes (MAC, C5b‐9). In order to protect themselves from the complement attack, the cells express several regulatory molecules, including the terminal complex regulator CD59 that inhibits assembly of the large MACs by inhibiting the insertion of additional C9 molecules into the C5b‐9 complex. Using the whole cell patch clamp method, we were able to measure accumulation of homologous MACs in the membrane of CD59− human B‐cells, which formed non‐selective ion channels with a total conductance of 360 ± 24 pS as measured at the beginning of the steady‐state phase of the inward currents. C5b‐8 and small‐size MAC (MAC containing only a single C9) can also form ion channels. Nevertheless, in CD59+ human B‐cells in spite of small‐size MAC formation, an ion current could not be detected. In addition, restoring CD59 to the membrane of the CD59− cells inhibited the serum‐evoked inward current. The ion channels formed by the small‐size MAC were therefore sealed, indicating that CD59 directly interfered with the pore formation of C5b‐8 as well as that of small‐size C5b‐9. These results offer an explanation as to why CD59‐expressing cells are not leaky in spite of a buildup of homologous C5b‐8 and small‐size MAC. Our experiments also confirmed that ion channel inhibition by CD59 is subject to homologous restriction and that CD59 cannot block the conductivity of MAC when generated by xenogenic (rabbit) serum.
Compatible osmolytes modulate the response of porcine endothelial cells to hypertonicity and protect them from apoptosis
Authors: Alfieri Roberta R. , Cavazzoni Andrea , Petronini Pier Giorgio , Bonelli Mara A. , Caccamo Alessandro E. , Borghetti Angelo F. , Wheeler Kenneth P.
Published: July 2002

Porcine pulmonary arterial endothelial cells accumulated myo‐inositol and taurine, as well as betaine, during adaptation to hypertonic stress. The cells grew and maintained their normal morphology during culture in hypertonic (0.5 osmol (kg H2O)−1) medium that contained osmolytes such as betaine, myo‐inositol or taurine at concentrations close to reported physiological values. The cells did not grow well in hypertonic medium depleted of potential compatible osmolytes. After a few days, cell density decreased by about 50 % and many cells rounded up and detached from the plates, their nuclei showing clear apoptotic morphology. The caspase‐3 activity of the cells also increased dramatically under these conditions, but remained negligibly low when betaine and myo‐inositol were added to the medium. Addition of betaine and myo‐inositol to hypertonic medium depleted of compatible osmolytes increased the number of colonies remaining after 12 days of culture; with each solute at 30–100 μmol l−1 the number increased about sixfold. In the absence of compatible osmolytes, increased mRNA levels and corresponding activities of betaine/γ‐aminobutyric acid transporter (BGT1) and sodium/myo‐inositol transporter (SMIT) induced by hypertonicity remained high after 72 h incubation, whereas they were down regulated in the presence of betaine and myo‐inositol. Similarly, the down regulation of the amino acid System A transporter (ATA2) was markedly slowed in the absence of compatible osmolytes. We conclude that these compatible osmolytes at concentrations close to physiological values enable the endothelial cells to adapt to hypertonic stress, protecting them from apoptosis, and also modulate the adaptation process.
Warpage Measurement on Dielectric Rough Surfaces of Microelectronics Devices by Far Infrared Fizeau Interferometry1
Authors: Verma K. , Han B.
Published: July 2002

Far infrared Fizeau interferometry is developed and it is proposed as a tool for warpage measurement of microelectronics devices. The method provides a whole-field map of surface topography with a basic measurement sensitivity of 5.31 μm per fringe contour. The method is implemented by a compact apparatus using a computer controlled environmental chamber for real-time measurement. The method retains the simplicity of classical interferometry while providing wide applicability to dielectric rough surfaces. Roughness tolerance is achieved by utilizing a far infrared light (λ=10.6 μm). The detailed optical and mechanical configuration is described and selected applications are presented to demonstrate the applicability. The unique advantages of the method are discussed. [S1043-7398(00)01303-7]
Validation of a New TVD Scheme Against Measured Pressure Waves in the Inlet and Exhaust System of a Single Cylinder Engine
Authors: Vandevoorde M. , Sierens R. , Dick E.
Published: July 2002

Recently a new TVD scheme was presented by the authors and a comparison was made with other algorithms for two engine related test cases (the shock tube and the tapered pipe). It was shown that the new scheme combines high accuracy with exact conservation of the mass flow, even in tapered pipes. In this paper the pressure waves in the inlet and exhaust system of a single cylinder engine are measured and compared to calculations with the new algorithm. The comparison is made under motoring and firing conditions of the engine with two different external mixture formation systems (different fuels: gasoline and methane). Modifications on intake and exhaust pipe configuration clearly show their influence on the pressure wave development. The importance of the loss coefficients for the flow through the inlet and exhaust valves (mass flow coefficient) is demonstrated. A test rig has been built to obtain these coefficients under steady-state conditions as a function of valve lift and mass flow rate. It is shown that for this engine configuration the measured steady-state loss coefficients are not reliable at low valve lifts. This can be explained by the influence of the Reynolds number and the appearance of a transition zone. For all mentioned comparisons the agreement is excellent. The next phase will be to evaluate the code for multi-cylinder engines under atmospheric and turbo-charged conditions. [S0742-4795(00)00204-0]