bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of human matriptase by eglin c variants
Authors: Désilets Antoine , Longpré Jean-Michel , Beaulieu Marie-Ève , Leduc Richard
Published: March 2006

Based on the enzyme specificity of matriptase, a type II transmembrane serine protease (TTSP) overexpressed in epithelial tumors, we screened a cDNA library expressing variants of the protease inhibitor eglin c in order to identify potent matriptase inhibitors. The most potent of these, R1K4′‐eglin, which had the wild‐type Pro45 (P1 position) and Tyr49 (P4′ position) residues replaced with Arg and Lys, respectively, led to the production of a selective, high affinity (K
i of 4 nM) and proteolytically stable inhibitor of matriptase. Screening for eglin c variants could yield specific, potent and stable inhibitors to matriptase and to other members of the TTSP family.
Hyperhomocysteinemia increases damage on brain slices exposed to in vitro model of oxygen and glucose deprivation: prevention by folic acid
Authors: Tagliari Bárbara , Zamin Lauren L. , Salbego Christianne G. , Netto Carlos Alexandre , Wyse Angela T.S.
Published: March 2006

In the present study we evaluate the effects of homocysteine on cellular damage using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation), an in vitro model of hypoxic–ischemic events. For chronic treatment, we induced elevated levels of homocysteine in blood (500 μM), comparable to those of human homocystinuria, and in brain (60 nmol/g wet tissue) of young rats by subcutaneous injections of homocysteine (0.3–0.6 μmol/g of body weight), twice a day with 8 h intervals, from the 6th to the 28th postpartum day and controls received saline. Rats were sacrificed 1, 3 or 12 h after the last injection. For acute treatment, 29‐day‐old rats received one single injection of homocysteine (0.6 μmol homocysteine/g body weight) or saline and were sacrificed 1 h later. In another set of experiments rats were pretreated with Vitamins E (40 mg/kg) and C (100 mg/kg) or folic acid (5 mg/kg) during 1 week; 12 h after the last administration they received a single injection of homocysteine or saline and were sacrificed 1 h later. Results showed that both chronic (1 h after homocysteine administration) and acute hyperhomocysteinemia increased the cellular damage measured by LDH released to de incubation medium, suggesting an increase of tissue damage caused by OGD. Pretreatment with folic acid completely prevented the damage caused by acute hyperhomocysteinemia, whereas Vitamin E just partially prevented such effect. These findings may be relevant to explain, at least in part, the higher susceptibility of hyperhomocysteinemic patients to be susceptible to ischemic events and point to a possible preventive treatment.
Examining the effects of contextual factors on TQM and performance through the lens of organizational theories: An empirical study
Authors: Sila Ismail
Published: March 2006

Although much has been written about TQM, little attention has been paid to the potential effects of contextual factors on TQM and TQM–performance relationships. The use of organizational theory to formulate propositions regarding the effects of such factors is especially scarce in the TQM literature. This study uses institutional theory and contingency theory as the basis to test a number of such propositions. First, a model of TQM and organizational performance is developed. Then using survey data, the effects of five contextual factors – three institutional factors and two contingency factors – on the implementation of TQM practices and on the impact of TQM on key organizational performance measures are analyzed within a TQM–performance relationships model framework. The three institutional factors include TQM implementation, ISO 9000 registration, and country of origin, and the two contingency factors include company size and scope of operations. The results show that the implementation of all TQM practices is similar across subgroups of companies within each contextual factor. In addition, the effects of TQM on four performance measures, as well as the relationships among these measures, are generally similar across subgroup companies. Thus, for the five contextual factors analyzed, the overall findings do not provide support for the argument that TQM and TQM–performance relationships are context‐dependent. The implications of the study for managers and researchers, as well as study limitations, are also discussed.
Legitimacy and the use of force: can the circle be squared?
Authors: HURRELL ANDREW
Published: March 2006

It is no great surprise that in the contemporary world the use of deadly force by a political grouping or nation-state or on behalf of international society should raise troubling questions of legitimacy. The problem appears to be massively overdetermined and the intellectual challenge is to bring some order to a confused and confusing debate; to distinguish between short-term problems and deep-rooted changes in both understandings of legitimacy and patterns in the use of force; and try and identify where there might be scope for narrowing the very deep disagreements that have come to surround this question.
Liberal hierarchy and the licence to use force
Authors: REUS-SMIT CHRISTIAN
Published: March 2006

Determining when states can use force legitimately is the central normative problematic in world politics. Domestically, constraining the state’s use of force with social and legal norms that confine state-sanctioned violence to a limited and clearly defined set of purposes and circumstances is essential to the maintenance of civil society and the protection of basic human rights. Internationally, circumscribing the conditions under which states may use force legitimately is critical to the maintenance of peace and stability in international society. And the degree to which legitimate force may be used internationally to constrain illegitimate force domestically lies at the heart of the problematic relationship between order and justice in world politics.
Peacekeeping and enforcement action in Africa: the role of Europe and the obligations of multilateralism
Authors: GRAY CHRISTINE
Published: March 2006

The duties, if any, of European states to participate in multilateral operations in Africa are currently a matter of some controversy. What are the obligations of European states with regard to the maintenance of international peace and security in Africa? How far is it legitimate for them to avoid the contribution of troops to UN peacekeeping operations in Africa? Does the reluctance of European and other developed states to participate in UN peacekeeping operations in Africa have significant legal consequences? This article will consider these issues in three main sections. The first provides an overview of UN peacekeeping in recent years at a time when there has been a substantial surge in demand for peacekeeping troops. It discusses the problems that the UN has faced in securing troops from developed member states, particularly for operations in Africa. The second section describes the pattern which has emerged in recent practice with regard to peacekeeping and enforcement action in Africa. Although developed states have generally been reluctant to provide troops for UN peacekeeping operations in Africa, they have undertaken Chapter VII operations in the Democratic Republic of Congo (DRC), Liberia and Côte d’Ivoire as ‘coalitions of the willing’. They have also provided assistance to certain African governments threatened with violent overthrow, such as the governments of Sierra Leone and Côte d’Ivoire. They have turned to regional and sub-regional organisations to take the lead in certain conflicts: they have provided financial assistance, logistical support and military training for such organisations.
Identity, legitimacy, and the use of military force: Russia’s Great Power identities and military intervention in Abkhazia
Authors: HOPF TED
Published: March 2006

An action is legitimate if the pertinent community deems it so. Most would agree that Russia’s conduct in the 1990s in Georgia was illegitimate. Military intervention in another state, unless the other state is preparing an imminent attack on one’s own territory, or is engaged in the systematic abuse of one’s own citizens, is a violation of the international norm of sovereignty, at a minimum. Some have argued that European politics has gone beyond this ‘territorial integrity norm’ to something more expansive, to a consensual renunciation of any and all territorial claims on other states. This was first codified in the Helsinki Final Act of 1975.
Dead or alive: American vengeance goes global
Authors: SHERRY MICHAEL
Published: March 2006

After 11 September 2001, the Administration of George W. Bush dismissed any criminal-justice model, put forth by various voices at home and abroad, for understanding and combating terrorism. This was ‘war’, the President insisted on 17 September, as he did repeatedly – directly, implicitly, and by analogy – in his 20 September address to Congress and on many later occasions, with American war in Afghanistan and later Iraq making that claim true. The criminal-justice model persisted, however, not least in Bush’s more colourful rhetoric. As he commented on the 17th regarding Osama bin Laden, ‘There’s an old poster out west, as I recall, that said, ‘‘Wanted: Dead or Alive” ’. On the 20th came his odd analogy, ‘Al Qaeda is to terror what the mafia is to crime’. On 11 October, drawing on crime-fighters’ lingo, he announced a ‘Most Wanted Terrorist list’ as part of his effort to ‘round up’ – both cowboy and cop words – ‘the evildoers’. In word and action, he kept blurring the neat line between war and crime he asserted.
Force and Legitimacy in World Politics: Introduction
Authors: ARMSTRONG DAVID , FARRELL THEO
Published: March 2006

This volume was produced in the context of the crisis of legitimacy that occasioned the 2003 Iraq War. As is well known, a bitter feud broke out in the United Nations Security Council (UNSC) over the legality of using force against Iraq. The US government justified going to war in the context of a new doctrine of preventive use of force for self-defence – a doctrine that was soon named after President George W. Bush. The British government anchored its case for war in two previous UNSC resolutions; res. 678 which originally authorised use of force against Iraq in the 1990–91 Gulf War, and res. 687 which suspended res. 678 on a number of conditions including the disarming of Iraq’s weapons of mass destruction (WMD) stockpiles, facilities and programmes. Both the US and British positions were underpinned by intelligence, subsequently proved to be flawed, that Iraq had failed to get rid of its WMD. Opponents of the war disputed this intelligence and, moreover, argued that the Bush Doctrine was plain illegal and ridiculed the British idea of resurrecting twelve-year-old UNSC resolutions.
MikroMental Test
Authors: Gutzmann Hans , Schmidt Karl-Heinz , Rapp Michael A. , Rieckmann Nina , Folstein Marshal F.
Published: March 2006

Zusammenfassung: Der MikroMental Test ist ein in Anlehnung an die Mini-Mental-Status Untersuchung (MMSE) entwickeltes Kurzverfahren zum Screening bei Verdacht auf eine demenzielle Erkrankung. In der vorliegenden Arbeit wurde die Reliabilität und die diagnostische Validität einer deutschsprachigen Version (MikroMental Test) untersucht. 125 gerontopsychiatrische Patienten mit einer Demenzdiagnose (mittleres Alter 77.8 ± 8.0 Jahre) und 77 Probanden ohne Demenzdiagnose (mittleres Alter 71.1 ± 7.0 Jahre), darunter 43 gesunde ältere Kontrollpersonen (mittleres Alter 69.7 ± 6.8 Jahre) wurden mittels der MMSE und des MikroMental Tests untersucht. Als Außenkriterium diente die Diagnose nach ICD-10. Die Durchführung des MikroMental Tests dauerte im Mittel 8 Minuten, für die MMSE wurden durchschnittlich 15 Minuten benötigt. Testwiederholungsanalysen zeigten eine befriedigende Reliabilität. Analysen der Sensitivität und Spezifität ergaben für den MikroMental Test Parameter diagnostischer Güte, die mit der MMSE vergleichbar, hinsichtlich einzelner Werte sogar statistisch bedeutsam überlegen sind. Für den ambulanten Bereich stellt der MikroMental Test aufgrund seiner Kürze und seiner diagnostischen Güte ein geeignetes Instrument zum Demenzscreening dar.
Der DemTect in der klinischen Anwendung
Authors: Kalbe Elke , Brand Matthias , Kessler Josef , Calabrese Pasquale
Published: March 2006

Zusammenfassung: Kognitive Screeningtests sind hilfreiche Instrumente zur Unterstützung der Demenzdiagnose. Der im Jahr 2000 eingeführte DemTect stellt ein im deutschsprachigen Raum mittlerweile vielfach angewendetes Screeningverfahren dar, das mit dem Ziel entwickelt wurde, möglichst sensitiv zu sein und damit Demenzen in Frühstadien sowie leichte kognitive Störungen (Mild Cognitive Impairment, MCI) erkennen zu können. In diesem Beitrag werden bisherige Befunde zur Anwendung des DemTects bei verschiedenen Indikationen unter besonderer Berücksichtigung der Frage nach Sensitivität und Spezifität des Verfahrens dargestellt und weiterer Forschungsbedarf aufgezeigt. Zusammenfassend hat sich der DemTect bislang sowohl im Rahmen der Diagnostik von Demenzsyndromen unterschiedlicher Ätiologie - Alzheimer Demenz und vaskuläre Demenz - als auch bei Patienten mit MCI bewährt. Erste positive Ergebnisse zur Anwendbarkeit bei dementen Parkinsonpatienten liegen ebenfalls vor. In allen Studien zeichnet sich der DemTect durch eine besonders hohe Sensitivität für demenzassoziierte kognitive Störungen aus. Eine entsprechende Empfehlung des Verfahrens wurde auch in die deutschen Richtlinien zur Diagnose und Therapie der Alzheimer Demenz und Demenz mit Lewy-Körperchen aufgenommen.
Die Störungsgradsensitivität des SKT
Authors: Lehfeld Hartmut , Erzigkeit Hellmut
Published: March 2006

Zusammenfassung: Der SKT nach Erzigkeit ist ein 1977 publizierter, seitdem zweimal überarbeiteter Kurztest zur Erfassung von Störungen des Gedächtnisses und der Aufmerksamkeit. Der Test wird hauptsächlich bei Patienten mit leichten kognitiven Beeinträchtigungen oder mit leichter bis mittelgradiger demenzieller Symptomatik eingesetzt. Der vorliegende Literaturüberblick informiert über quer- und längsschnittliche Studien, in denen sich der SKT als störungsgradsensitives Untersuchungsverfahren bewährt hat. Auch wenn der Schwerpunkt des Testeinsatzes im Bereich demenzieller Alterserkrankungen liegt - hier insbesondere auf dem Wirksamkeitsnachweis therapeutischer Maßnahmen -, belegen zahlreiche Untersuchungen beispielsweise aus der Chirurgie und Anästhesie seine Verwendbarkeit auch bei anderen Diagnosegruppen. Als besonderer Vorteil des SKT erwies sich hierbei das Vorliegen von fünf Parallelformen für Wiederholungstestungen innerhalb kurzer Zeitabstände. Die differenzierte Altersnormierung, die auch das prämorbide Ausgangsniveau des Patienten berücksichtigt, macht den SKT zu einem Verfahren mit einem breiten Einsatzbereich.
Pain Influences Several Levels of Attention
Authors: von Bueren Jarchow Astrid , Radanov Bogdan P. , Jäncke Lutz
Published: March 2006

Abstract: The aim of the present study was to examine to what extent chronic pain has an impact on various attentional processes. To measure these attention processes a set of experimental standard tests of the “Testbatterie zur Aufmerksamkeitsprüfung” (TAP), a neuropsychological battery testing different levels of attention, were used: alertness, divided attention, covert attention, vigilance, visual search, and Go-NoGo tasks. 24 chronic outpatients and 24 well-matched healthy control subjects were tested. The control subjects were matched for age, gender, and education. The group of chronic pain patients exhibited marked deficiencies in all attentional functions except for the divided attention task. Thus, the data supports the notion that chronic pain negatively influences attention because pain patients` attention is strongly captivated by the internal pain stimuli. Only the more demanding divided attention task has the capability to distract the focus of attention to the pain stimuli. Therefore, the pain patients are capable of performing within normal limits. Based on these findings chronic pain patients' attentional deficits should be appropriately evaluated and considered for insurance and work related matters. The effect of a successful distraction away from the pain in the divided attention task can also open new therapeutic aspects.
Rapid inverse modeling of pressure interference tests using trajectory‐based traveltime and amplitude sensitivities
Authors: He Zhong , Datta‐Gupta Akhil , Vasco D. W.
Published: March 2006

This paper presents an efficient trajectory‐based approach to integrate transient pressure data into high‐resolution reservoir and aquifer models. The method involves alternating traveltime and peak amplitude matching of pressure response using inverse modeling and is particularly well suited for high‐resolution subsurface characterization using hydraulic tomography or pressure interference tests. Compared to traveltime inversion only, our proposed approach results in a significantly improved match of the pressure response at the wells and also better estimates of subsurface properties. This is accomplished with very little increase in computational cost. Utilizing the concept of a “diffusive” time of flight derived from an asymptotic solution of the diffusivity equation, we develop analytical approaches to estimate the sensitivities for traveltime and peak amplitude of pressure response to subsurface properties. The sensitivities are then used in an iterative least squares minimization to match the pressure data. We illustrate our approach using synthetic and field examples. In the field application at a fractured limestone formation the predominant fracture patterns emerging from the inversion are shown to be consistent with independent geophysical experiments and borehole data.
Nutrient streams and their induction into the mixed layer
Authors: Williams Richard G. , Roussenov Vassil , Follows Michael J.
Published: March 2006

Nutrients are transferred from the nutricline into the winter mixed layer through a combination of vertical and lateral advection, referred to here as induction, the reverse of the subduction process. This advective supply of nutrients maintains the high productivity at high latitudes over timescales of several years and longer. Climatological diagnostics over the North Atlantic reveal that the induction of nutrients into the winter mixed layer is dominated by lateral advection even in the subpolar gyre where there is significant Ekman upwelling. The induction flux of nutrients is itself sustained by nutrient streams, strong nutrient transport associated with the western boundary currents. In the North Atlantic basin, the integrated induction flux accounts for typically 40% of the nitrate flux in the nutrient stream at 36°N, while the remaining fraction is recirculated in the thermocline of the subtropical gyre. The relationship between the nutrient stream and induction flux is illustrated using a numerical model of the circulation and biogeochemistry of the North Atlantic. The model studies suggest that the nutrient stream preferentially supplies nutrients to isopycnals outcropping in the subpolar gyre. The nutrient sources for the nutrient stream are either mode waters originating from the Southern Ocean or the tropics, where the eastern upwelling circulation and particle fallout focuses nutrients onto the lighter isopycnal surfaces of the nutrient stream.
Crustal velocity structure across the southern Korean Peninsula from seismic refraction survey
Authors: Cho Hyun‐Moo , Baag Chang‐Eob , Lee Jung Mo , Moon Wooil M. , Jung Heeok , Kim Ki Young , Asudeh Isa
Published: March 2006

The first crustal‐scale controlled source seismic refraction experiment in the southern Korean Peninsula, KCRUST2002, was carried out along a 300‐km long profile across this peninsula in December 2002. Iterative processing and modeling produced a laterally varying layered crustal velocity model. The crust is thickest (34 km) below the Okcheon fold belt in the middle of the transect and thinnest (28 km) at the eastern end where the Cretaceous Gyeongsang basin is characterized by 5 km of low velocity material that constitutes the upper crust. The P velocities in upper and lower crust range from 5.4 to 6.0 km/s and from 6.4 to 6.7 km/s, respectively. The average crustal Poisson's ratio is found to be 0.25–0.27 (Vp/Vs = 1.73−1.78) along the profile. A mid‐crustal velocity discontinuity is recognized in the northwestern part of the transect. The underlying mantle has velocities in the range of 7.9–8.1 km/s.
Evaluations of spatial distribution of submarine groundwater discharge
Authors: Taniguchi Makoto , Ishitobi Tomotoshi , Shimada Jun , Takamoto Naohiko
Published: March 2006

The paired catchments with the same basin size and meteorological condition but different geology were selected to compare the fresh submarine groundwater discharge (SGD) rate observed by seepage meters with value calculated from water balance method in Kumamoto, Japan. The fresh SGD rate decreases with the distance from the coast, on the other hands, recirculated saline SGD is higher at near shore due to wave set‐up and at offshore due to tidal pumping. The spatial integrations of fresh SGD agree well with the water budget in both paired catchments. The difference of fresh component of SGD between two catchments may be caused by the difference of geology in the study area.
Spatiotemporal variation in b value within the subducting slab prior to the 2003 Tokachi‐oki earthquake (M 8.0), Japan
Authors: Nakaya Shinji
Published: March 2006

The b value of an earthquake catalogue, defined as the slope of the Gutenberg‐Richter frequency‐magnitude relationship (logN = a − bM), is typically close to unity in many tectonic settings. However, analysis of seismicity data for the subducting slab along the Kuril Trench reveals a zone of anomalously low b values near the hypocenter of the 2003 Tokachi‐oki earthquake (M 8.0). The zone of low b value (0.50–0.65) at depths of less than 80 km in the subducting slab changes in location with time in 1990–2003 and intensifies leading up to the 2003 earthquake. This transient low b value zone corresponds roughly with the location of an asperity inferred from waveform inversion in recent research. In the shallow zone corresponding to the immediate region (<125 km along the subducting slab) of the 2003 event, the b value is shown to have decreased in the year prior to the main shock from initial values of ∼0.65 to values as low as 0.5. The occurrence of the 2003 earthquake, a large thrust event on the subducting plate interface, in this zone of anomalously low b values suggests that low b values in the subducting slab prior to the main shock and during the aftershock series are concordant with high stress concentrations associated with interseismic strain accumulation and redistribution in the vicinity of the rupture.
Prediction of velocity statistics in three‐dimensional multi‐Gaussian hydraulic conductivity fields
Authors: Englert Andreas , Vanderborght Jan , Vereecken Harry
Published: March 2006

To study statistics of velocity fields in three‐dimensional heterogeneous multi‐Gaussian saturated hydraulic conductivity fields and the accuracy of their prediction, we performed high‐resolution Monte Carlo (MC) analyses. The MC analyses included variances of the log hydraulic conductivity in the range of 0.5 ≤ σY2 ≤ 3.0 and anisotropy ratios in the range of 0.017 ≤ e ≤ 1. The statistics of the velocity fields from the MC analyses are compared with analytical solutions of the first‐ and second‐order approximations of the stochastic flow equation. This paper shows that the second‐order approximations fit significantly better to the univariate statistics of the Darcy velocity from the MC analyses. For isotropic cases the second‐order approximations correspond fairly well to the univariate statistics of the velocity. For anisotropic cases the accordance is given only for the mean velocity and the variance of the transverse vertical component of the velocity. The MC analyses show that the spatial correlation of the velocity decreases more rapidly with increasing σY2. This was more pronounced for the anisotropic than for the isotropic case. The negative correlations, in absolute terms, of the transverse velocity components simultaneously decrease with increasing σY2. This is in contrast to the first‐order approximation of the spatial correlations of the velocity. It is assumed that the discrepancies between approximate solutions of the stochastic flow equation and the results of the MC analyses are strongly dependent on the nonnormality of the probability density distributions of the velocity.
Characterization of a cry4Ba‐type gene of Bacillus thuringiensis israelensis and evidence of the synergistic larvicidal activity of its encoded protein with Cry2A δ‐endotoxin of B. thuringiensis kurstaki on Culex pipiens (common house mosquito)
Authors: Zghal Raida Zribi , Tounsi Slim , Jaoua Samir
Published: March 2006

A newly isolated strain of Bacillus thuringiensis, named BUPM97, was identified as affiliated to the israelensis subspecies. This strain was selected for its insecticidal activity against larvae of several dipteran insects, such as the common house mosquito (Culex pipiens). A 5 kb EcoRI fragment, containing a cry4Ba‐type gene, named cry4BLB, was cloned from BUPM97. The sequencing of this gene revealed an open reading frame of 3411 bp encoding a protein of 1136 amino acid residues. Similarity analysis of both nucleotide and amino acid sequences revealed that cry4BLB presents several differences from the other previously described cry4Ba‐type genes. Particular attention was paid to a two‐amino‐acid substitution located in domain III of the N‐terminal moiety of this protein, which is very important for both toxicity and specificity of the toxin. The transfer of cry4BLB to an acrystalliferous B. thuringiensis kurstaki strain, HD1CryB, showed that it was expressed, resulting in the production of the typical parasporal crystal inclusions. On the other hand, its transfer to another B. thuringiensis kurstaki strain synthesizing Cry2A endotoxin known to be weakly toxic to the dipteran insect C. pipiens, resulted in the clear increase in the insecticidal activity of the transformed strain. Hence, in the present paper, we demonstrate for the first time that Cry2A and Cry4B act synergistically towards C. pipiens.
Biologically active vascular endothelial growth factor as a bacterial recombinant glutathione S‐transferase fusion protein
Authors: Morera Yanelys , Lamdan Humberto , Bequet Mónica , Ayala Marta , Rojas Gertrudis , Muñoz Yasmiana , Gavilondo Jorge V.
Published: March 2006

Human VEGF121(vascular endothelial growth factor isoform 121) was produced as a recombinant fusion protein with GST (glutathione S‐transferase) inEscherichia coli. After affinity purification with glutathione, the GST–VEGF121fusion protein preparation was used to obtain antibodies in mice against commercial hrVEGF (human recombinant VEGF) through immunization. It was also employed successfully to select specific antihuman VEGF antibody fragments of human origin employing phage‐display technology. The fusion protein preparation was separated in monomeric, dimeric and oligomeric forms using size‐exclusion chromatography. The dimers were recognized by a soluble VEGF receptor 2–Fc chimaera, and stimulated the growth of human umbilical‐vein endothelial cellsin vitroin a similar fashion to a commercial hrVEGF. The presence of GST in the fusion protein apparently did not affect the correct assembly of dimers and display of residues critical for receptor recognition. The two‐step purification method reported in the present paper involves no laborious renaturalization methods, yields 10 mg/l of the mixture of different aggregation states after affinity chromatography, and 5 mg/l of the biologically active dimer after gel filtration, thus providing a source of material for the development of new anti‐angiogenic therapeutic molecules.
Quantification of fluorescence in thick specimens, with an application to cyclin B—GFP expression in starfish oocytes
Authors: Terasaki Mark
Published: March 2006

Background information. Fluorescence imaging of living cells is widely used in cell biology. It is now being extended to thick specimens such as large cells or tissues where it is important to establish methods for obtaining quantitative fluorescence data due to the increasing importance of computational and systems biology approaches.

Results. Fluorescent solutions were used as a calibration standard for determining cellular fluorescence concentrations from z series image sequences. The accuracy of the measurements was evaluated using quantitatively injected cells. Different fluorescence attenuation rates of the cytoplasm and nucleoplasm were documented, and autofluorescence levels were determined. This method was used to characterize the effect of cyclin B overexpression on cell‐cycle timing in starfish oocytes. The time interval between application of maturation hormone and germinal vesicle breakdown decreased with increasing cyclin B—GFP (green fluorescent protein) concentration to a level of 100–300 nM, beyond which there was no effect.

Conclusions. Conditions for determining fluorescent probe concentrations in large cells or multicellular tissues were established, which will facilitate the collection of data for quantitative studies. This method was used to characterize the effect of cyclin B—GFP expression levels on cell‐cycle timing in starfish oocytes.
Effects of tumour necrosis factor α (TNFα) on Mytilus haemocytes: role of stress‐activated mitogen‐activated protein kinases (MAPKs)
Authors: Betti Michele , Ciacci Caterina , Lorusso Lucia C. , Canonico Barbara , Falcioni Tania , Gallo Gabriella , Canesi Laura
Published: March 2006

Background information. Many studies indicate that innate immunity in invertebrates can be modulated by a cytokine network like in vertebrates. In molluscs, the immune response is carried out by circulating haemocytes and soluble haemolymph factors. In the present study, the effects of heterologous TNFα (tumour necrosis factor α) on cell signalling and function in the haemocytes of the bivalve Mytilus galloprovincialis Lam. were investigated.

Results and conclusions. Addition of TNFα in the absence of haemolymph serum [in ASW (artificial sea water)] induced cellular stress, as indicated by lysosomal destabilization, and decreased phagocytosis; on the other hand, in the presence of serum, TNFα did not affect lysosomal stability and even stimulated phagocytosis. TNFα induced rapid phosphorylation of the stress‐activated p38 and JNK (c‐Jun N‐terminal kinase) MAPKs (mitogen‐activated protein kinases); both effects were persistent in ASW but transient in serum. Activation of p38 and JNKs in mediating the effects of TNFα was confirmed by the use of specific MAPK inhibitors. Moreover, flow cytometric analysis indicated that TNFα in the presence of serum induced transient phosphatidylserine exposure on the haemocyte surface, evaluated as annexin V binding; in ASW, the cytokine resulted in a stable increase in the percentage of both annexin‐ and propidium iodide‐positive cells, indicating possible apoptotic/necrotic processes. The results indicate that TNFα can affect the function of bivalve haemocytes through conserved transduction pathways involving stress‐activated MAPKs and suggest that the haemocyte response to the cytokine is influenced by soluble haemolymph components.
Exploring complexity when diversity is limited: institutional complementarity in theories of rule of law and national systems revisited
Authors: Kogut Bruce , Ragin Charles
Published: March 2006

Categories reflect particular theories about the world in the form of causal and performative claims. Unlike attributes that are the mainstay of statistical analysis, these discrete entities consist of the contradiction of being easy to understand and yet hard to analyze. An important obstacle to the exploration of causal claims about categories (e.g. nations) is the limited diversity of observed cases. We propose the use of methodologies that take greater exploratory account of causal complexity and that respects the importance of case narratives for theexplicitdecisions made to arrive at theoretical claims. One such methodology is qualitative comparative analysis developed by Charles Ragin. This method is applied to data provided by two independent lines of study (i.e. rule of law and governance and varieties of capitalism) to show how the identification, and adoption, ofprototypesis complex. Through the use of logic (e.g. De Morgan's law) and reductive inferences, we explore the space of observed and unobserved configurations, showing how the identification of institutional configurations relies upon logical assumptions that are rarely made explicit. The analysis rejects the hypothesis of rule of law and financial development and qualifies the institutional prototypes of corporatism and market as useful descriptions of the varieties of capitalism.
Relevance in business research: the case of country‐of‐origin research in marketing
Authors: Usunier Jean‐Claude
Published: March 2006

A popular research topic in international marketing is how a product's country‐of‐origin influences consumer evaluations (COO research). The purpose of this contribution is to explore how COO research has developed over time in growing disconnection with both consumer and corporate concern. We offer a number of possible explanations to this ‘relevance gap,’ with the caveat that these explanations may be contingent to the COO case study.
Systematic process analysis: when and how to use it
Authors: Hall Peter A
Published: March 2006

Challenging the contention that statistical methods applied to large numbers of cases invariably provide better grounds for causal inference, this article explores the value of a method of systematic process analysis that can be applied in a small number of cases. It distinguishes among three modes of explanation — historically specific, multivariate, and theory‐oriented — and argues that systematic process analysis has special value for developing theory‐oriented explanations. It outlines the steps required to perform such analysis well and illustrates them with reference to Owen's investigation of the ‘democratic peace’. Comparing the results available from this kind of method with those from statistical analysis, it examines the conditions under which each method is warranted. Against conceptions of the ‘comparative method’ which imply that small‐ncase‐studies provide weak grounds for causal inference, it argues that the intensive examination of a small number of cases can be an appropriate research design for testing such inferences.
Can methods for analysing large numbers organize a productive dialogue with the actors they study?
Authors: Callon Michel
Published: March 2006

The creation of categories based on an analysis of large numbers of heterogeneous entities does not preclude the establishment of productive interactions with the entities studied. The nature of these interactions and the types of objectification they allow depend on the characteristics of the tools used. This article aims at characterizing the different methods in terms of the competencies they recognize in actors. Three types of methods are described: multidimensional analysis, social network analysis, and what is called ‘composition of egocentric heterogeneous networks’. The paper suggests that from one method to the next, the actors' competencies are enhanced. Consequently, the sociologist's ability to perceive the emergence of new categories increases; in endowing human and non‐human actors with larger and richer competencies, he upgrades his own competencies as an analyst. In addition, productive interactions between him and the actors he studies are made easier.
Reviving narratives in economics and management: towards an integrated perspective of modelling, statistical inference and narratives
Authors: Dumez Hervé , Jeunemaitre Alain
Published: March 2006

Most articles in economics and management rely on modelling and/or statistical inference with a tendency to disregard narratives. By contrast, this paper argues in favour of reviving their role. It proposes an integrated perspective of modelling, quantification and narratives. The perspective is based on a set of principles (organon), use of the exploratory dimension, and colligation of rival hypotheses. The integrated narrative perspective is developed through an examination of the relationships between modelling and narratives, on one hand, and narratives and quantitative analysis, on the other. It is based upon an analysis of the exposed narratives in a few major economics publications.
Cesium in hydrogen negative-ion sources
Authors: Belchenko Yu. I. , Davydenko V. I.
Published: March 2006

Experimental data on the dynamics of cesium particles in the pulsed magnetron and Penning surface-plasma ion sources are presented. Cesium escape from the source emission apertures and the cesium ion current to discharge electrodes was measured. The low value of cesium flux from the source was detected. An intense cesium ion current to the cathode (up to 0.8A∕cm2) was measured. The high value of cesium ion current to surface-plasma source cathode confirms the cesium circulation near the cathode.
Transport line for beam generated by ITEP Bernas ion source
Authors: Petrenko S. V. , Kropachev G. N. , Kuibeda R. P. , Kulevoy T. V. , Pershin V. I. , Masunov E. S. , Polozov S. M. , Hershcovitch A. , Johnson B. M. , Poole H. J.
Published: March 2006

A joint research and development program is underway to investigate beam transport systems for intense steady-state ion sources for ion implanters. Two energy extremes of MeV and hundreds of eV are investigated using a modified Bernas ion source with an indirectly heated cathode. Results are presented for simulations of electrostatic systems performed to investigate the transportation of ion beams over a wide mass range: boron to decaborane.
Study of a liquid metal ion source for external ion injection into electron-beam ion source
Authors: Pikin A. , Alessi J. G. , Beebe E. N. , Kponou A. , Prelec K.
Published: March 2006

A liquid metal ion source (LMIS) has several attractive features as an external injector of primary ions (mostly metallic ions) into electron-beam ion source (EBIS). It does not use a buffer gas and therefore it provides only a very small gas load to the system; its control and operation are simple, power consumption does not exceed 10W, and beam pulses are very stable. A gold-silicon LMIS was supplied by FEI Company (http://www.feibeamtech.com/pages/liquid.html) and tested in a pulsed regime with an ion pulse width of 2ms and frequency up to 5Hz. Total extracted ion current reached 50μA and the normalized emittance of the total ion beam was 0.05πmmmrad. The results of this test, as well as results of experiments in which this ion source is used for injection of Au ions into EBIS, are presented.
Why π and mrad?
Authors: Becker R. , Herrmannsfeldt W. B.
Published: March 2006

Today it is generally accepted in the ion source and accelerator communities to communicate emittance data with units of πmmmrad or πcmmrad. The emittance of a beam with 2cm diameter or width and an opening angle of 200mrad then is written as E=100πcmmrad. This example shows that π has not been involved when calculating the half-axis’ product which is the numerical definition for the emittance. Why should we add π to the dimensions? We will explain that this convention is not at all a logical one and is confusing to all those who are entering the field as freshmen or just do not want to become experts by adjusting to strange rules. We therefore propose to skip the “π” in the dimension and to add characters as sub- or superscripts to the variable E, which describe the specific kind of emittance formulation used, e.g., Er,r′, Ex,x′, Erms, E4*rms, Enorm, Earea, and Eellipse. In a real case, such an emittance naming could appear as Ex,x′,4rmsnorm. Additionally—to be consistent with cleaning up—the dimension of emittances should be given in centimeters or meters, because rad are ratios and free of dimension. Therefore, instead of using cm mrad it is much more logical to communicate emittance data by writing ε m, where ε is the product of the maximum value for half of the beam thickness in meters and its opening angle in rad.
Development of an angular-resolved momentum analyzer system to study particle reflections from solid surfaces
Authors: Yamaoka H. , Matsumoto Y. , Nishiura M. , Tsumori K. , Sugawara H. , Takeuchi S. , Shinto K. , Sasao M. , Wada M.
Published: March 2006

An experimental system designed to study systematically interactions of beams with solid surface is being developed. A small magnetic multicusp-type ion source is used to produce both positive and negative ions with a pair of removable filter magnets. The mass-separated extracted ions are then directed onto a solid target, and the angular distributions and energy spectra of the reflected ions are measured with a magnetic momentum analyzer. The performance of the system is tested by investigating the particle reflections from a polycrystalline W surface bombarded by low-energy (1–2 keV) H and O ions.
Profile of single-pulsed ion beams in acceleration gap
Authors: Xiang W. , Tang P. Y.
Published: March 2006

In an attempt to understand the characteristics of single-pulsed ion beams extracted from a miniature occluded-gas sources with electrodes of metallic hydride, a two-dimensional (2D) projected image of ion beams extracted from the single-pulsed occluded-gas source was captured using a digital charge-coupled device camera on a test bench. Based on image processing and the inverse Abel transform, the 2D integrally projected image with cylindrical symmetry was used to determine the profile of ion beams in the acceleration gap. The result shows that the radial beam profile in acceleration gap has a Gaussian-like shape, and the maximum beam intensity behind the plasma electrode is about 40% higher than that in front of the extraction electrode.
Development of ion sources for materials processing in china
Authors: Zhao W. J. , Ren X. T. , Zhao H. W.
Published: March 2006

This article reviews the development of ion sources for materials processing and the progress of commercial product of ion sources in China. The various ion-beam processing and the relative needs to ion sources are mentioned and discussed, such as ion sources with ion implantation, plasma immersion ion implantation, ion-beam-assisted deposition, ion-beam deposition, and so on. The states of progress for different kinds of ion sources specially for electron cyclotron resonance∕microwave, metal vapor vacuum arc, radio frequency (rf) ion source, end-Hall ion source, and cluster ion source, are given and discussed.
Numerical analysis of primary electrons in a tandem-type negative ion source
Authors: Katoh K. , Takado N. , Hatayama A. , Hanada M. , Seki T. , Inoue T.
Published: March 2006

To clarify the physical mechanism of the plasma spatial nonuniformity observed in tandem-type negative-ion sources, the primary electron-transport process has been analyzed by a three-dimensional Monte Carlo simulation code. In the model, equations of motion for electrons are numerically solved. The realistic geometry and magnetic-field configuration are taken into account. Various collision processes with neutral particles are also included in the model. The simulation results show that (1) the primary electrons have been lost from the source region to the extraction region due to the magnetic drift in the filter magnetic region and (2) the magnetic drift velocities have opposite directions near the sidewalls. The effect of the magnetic drift is one of the possible causes to explain the spatial nonuniformity observed in the experiment.
Causes and cures for errors in the simulation of ion extraction from plasmas
Authors: Becker R.
Published: March 2006

For many years, computer programs have been available to simulate the extraction of positive ions from plasmas. The results of such simulations may not always agree with measurements. There are different reasons for this: the mathematical formulation must match with the simulated physics, the number of meshes must be high enough to correctly take into account the nonlinear space charge in the sheath, and ray tracing must be done in sufficiently small steps, using numerically correct field components and partial derivatives. In addition to these hidden problems the user may create errors by a wrong choice of parameters, which are not matching the assumptions of the mathematical formulation. Examples are the use of a positive ion extraction program for the extraction of negative ones, the choice of a wrong angle between the plasma electrode and the beam boundary in the vicinity of the meniscus, and the use of too few trajectories. The design of extraction electrodes generally has the aim to optimize the optical properties and the current of the ion beam. However, it is also important to take into account the surface fields in order to avoid dark currents and sparking.
Surface cleaning and modification of Si(100) substrates by ethanol and water cluster ion beams
Authors: Takaoka Gikan H. , Noguchi Hidetaka , Nakayama Kazuya , Seki Takato , Kawashita Masakazu
Published: March 2006

The interactions of ethanol and water cluster ions with Si(100) substrates were investigated. The Si substrates were sputtered by the ethanol cluster ion beams, and the sputtering yield for the cluster ion irradiation at an acceleration voltage of 9kV was approximately 100 times larger than that for argon monomer ion irradiation at the same acceleration voltage. In addition, surface cleaning of the Si substrates, on which a small amount of metal vapors such as Cu, Al, and Au was deposited previously as contaminative particles, was performed by irradiation of the ethanol cluster ion beams. X-ray photoelectron spectroscopy measurements showed that the contaminative metal particles were removed from the Si surface at an ion dose of 1×1015ions∕cm2. Furthermore, contact angles as well as Fourier transform infrared spectra of the Si surfaces were measured, and the wettability of the surfaces changed drastically depending on the irradiation conditions of the ethanol and water cluster ions. This is ascribed to the difference in the chemical modification of the Si surfaces by the functional groups, which were produced after the impact of the ethanol and water cluster ions on the Si surfaces.
Influence of Bernstein modes on the efficiency of electron cyclotron resonance x-ray source
Authors: Andreev V. V. , Nikitin G. V. , Savanovich V. Yu. , Umnov A. M. , Elizarov L. I. , Serebrennikov K. S. , Vostrikova E. A.
Published: March 2006

The article considers the factors influencing the temperature of hot electron component in an electron cyclotron resonance (ECR) x-ray source. In such sources the electron heating occurs often due to extraordinary electromagnetic wave propagating perpendicularly to the magnetic field. In this case the possibility of the absorption of Bernstein modes is regarded as an additional mechanism of electron heating. The Bernstein modes in an ECR x-ray source can arise due to either linear transformation or parametric instability of external transversal wave. The article briefly reviews also the further experiments which will be carried out to study the influence of Bernstein modes on the increase of hot electron temperature and consequently of x-ray emission.
Development of a strong field helicon plasma source
Authors: Shinohara Shunjiro , Mizokoshi Hiroshi
Published: March 2006

We developed a high-density helicon plasma source with a very strong field of up to 10kG. Using a double-loop antenna wound around a quartz tube, 9.5cm in inner diameter and 90cm in axial length, initial plasmas with a high density more than 1013cm−3 were successfully produced with a radio frequency power less than a few kilowatts, and with changing magnetic fields, fill pressures, and gas species.