bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation, microstructure, and magnetic properties of bulk nanocrystalline Gd metal
Authors: Yue M. , Zhang J. X. , Zeng H. , Wang K. J.
Published: December 2006

Bulk nanocrystalline gadolinium metal was prepared using spark plasma sintering (SPS) and subsequent annealing process. The SPS Gd metal had a single phase with a mean grain size of about 10nm. A pressure-induced C-axis crystal texture was found in the SPS Gd sample. With the decrease of Gd grains from micrometer to nanometer range, the Curie temperature TC decreased by 10.7K and the magnetic moment per Gd atom at 5K dropped noticeably from 7.81μB to 6.31μB. These results indicate the remarkable influence of the nanostructure on the magnetism of Gd due to the finite size effect.
Thermally mediated breakup of drops in microchannels
Authors: Ting Teck Hui , Yap Yit Fatt , Nguyen Nam-Trung , Wong Teck Neng , Chai John Chee Kiong , Yobas Levent
Published: December 2006

The authors used thermally induced surface tension gradients to manipulate aqueous droplets in microchannels. Control of the droplet breakup process was demonstrated. Droplet sorting can be achieved with temperatures above a critical value. Numerical simulation using a two-dimensional model agrees qualitatively well with the experimental results. The used control temperature of less than 55°C shows that this active control concept is suitable for biochemical applications. Thermal control promises to be a simple and effective manipulation method for droplet-based lab on a chip.
Electron-beam-induced dissociation of B–D complexes in diamond
Authors: Barjon J. , Chevallier J. , Jomard F. , Baron C. , Deneuville A.
Published: December 2006

The diffusion of deuterium in boron-doped homoepitaxial diamond films leads to the passivation of boron acceptors via the formation of B–D complexes. In this letter, the stability of B–D pairs is investigated under the stress of a low-energy (10keV) electron-beam irradiation at low temperature (∼100K). The dissociation of the complexes is evidenced by cathodoluminescence spectroscopy and is shown to result in the reactivation of most acceptors. The dissociation yield per incident electron is found to be strongly dependent on the e-beam current, which suggests a dissociation involving a vibrational excitation of the complexes by hot electrons.
Effects of potential and duration of pulse width on sheath dynamics related to a target with a groove in two-dimensional simulation
Authors: Ghomi H. , Sharifian M. , Niknam A. R. , Shokri B.
Published: December 2006

In this paper, the temporal evolution of the ion-matrix sheath near a target with a rectangular groove as a function of time and potential is investigated numerically. A two-dimensional model with a single groove is adopted. The profiles of potential, ion density, and the normalized ion flux over the sidewall and the floor of the groove are obtained. These profiles are provided for insight regarding the uniformity and efficiency of ion implantation on the sidewall.
Nonlinear pulse-shaping phenomena of semiconductor saturable absorber mirror
Authors: Wang Jiun-Cheng , Sun Chi-Kuang , Wang Juen-Kai
Published: December 2006

The authors report the experimental investigation of pulse-shaping effects of a semiconductor saturable absorber mirror (SESAM). The induced pulse shortening and phase variation exhibit fluence dependences which follow the saturation behavior of nonlinear reflectivity. The experimental results have been compared with the prediction based on saturable population relaxation model. The study provides an unprecedented opportunity to investigate the role of SESAM in ultrafast mode-locked lasers.
Dysprosium scandate thin films as an alternate amorphous gate oxide prepared by metal-organic chemical vapor deposition
Authors: Thomas Reji , Ehrhart Peter , Luysberg Martina , Boese Markus , Waser Rainer , Roeckerath Martin , Rije Eduard , Schubert Juergen , Van Elshocht Sven , Caymax Matty
Published: December 2006

Dysprosium scandate (DyScO3) thin films were deposited on Si substrates using metal-organic chemical vapor deposition. Individual source precursors of Dy and Sc were used and deposition temperatures ranged from 480to700°C. Films were amorphous with low root mean square roughness (⩽2Å) and were stable up to 1050°C annealing. Electrical characterization yielded C-V curves with negligible hysteresis (<10mV), high dielectric constant (∼22), and low leakage currents. The electrical properties of the DyScO3∕SiOx∕Si stacks were stable up to 800°C for films on native oxide; however, this limit increased to 900°C for films on special chemically grown oxide, suggesting further improvement with proper diffusion barrier.
Two-dimensional vibrational optical probes for peptide fast folding investigation
Authors: Zhuang Wei , Abramavicius Darius , Mukamel Shaul
Published: December 2006

A simulation study shows that early protein folding events may be investigated by using a recently developed family of nonlinear infrared techniques that combine the high temporal and spatial resolution of multidimensional spectroscopy with the chirality-specific sensitivity of amide vibrations to structure. We demonstrate how the structural sensitivity of cross-peaks in two-dimensional correlation plots of chiral signals of an α helix and a β hairpin may be used to clearly resolve structural and dynamical details undetectable by one-dimensional techniques (e.g. circular dichroism) and identify structures indistinguishable by NMR.
Exosite interactions contribute to tension-induced cleavage of von Willebrand factor by the antithrombotic ADAMTS13 metalloprotease
Authors: Gao Weiqiang , Anderson Patricia J. , Majerus Elaine M. , Tuley Elodee A. , Sadler J. Evan
Published: December 2006

Von Willebrand factor (VWF) is a multimeric protein that mediates platelet adhesion at sites of vascular injury, and ADAMTS13 (a disintegrin and metalloprotease with thrombospondin)is a multidomain metalloprotease that limits platelet adhesion by a feedback mechanism in which fluid shear stress induces proteolysis of VWF and prevents disseminated microvascular thrombosis. Cleavage of the Tyr
1605
–Met
1606
scissile bond in the VWF A2 domain depends on a Glu
1660
–Arg
1668
segment in the same domain and on the noncatalytic spacer domain of ADAMTS13, suggesting that extensive enzyme–substrate interactions facilitate substrate recognition. Based on mutagenesis and kinetic analysis, we find that the ADAMTS13 spacer domain binds to an exosite near the C terminus of the VWF A2 domain. Deleting the spacer domain from ADAMTS13 or deleting the exosite from the VWF substrate reduced the rate of cleavage ≈20-fold. A cleavage product containing the exosite was a hyperbolic mixed-type inhibitor of ADAMTS13 proteolysis of either VWF multimers or model peptide substrates but only if the ADAMTS13 enzyme contained the spacer domain. The specificity of this unique mechanism depends on tension-induced unfolding of the VWF A2 domain, which exposes the scissile bond and exosite for interaction with complementary sites on ADAMTS13.
Influenza virus pleiomorphy characterized by cryoelectron tomography
Authors: Harris Audray , Cardone Giovanni , Winkler Dennis C. , Heymann J. Bernard , Brecher Matthew , White Judith M. , Steven Alasdair C.
Published: December 2006

Influenza virus remains a global health threat, with millions of infections annually and the impending threat that a strain of avian influenza may develop into a human pandemic. Despite its importance as a pathogen, little is known about the virus structure, in part because of its intrinsic structural variability (pleiomorphy): the primary distinction is between spherical and elongated particles, but both vary in size. Pleiomorphy has thwarted structural analysis by image reconstruction of electron micrographs based on averaging many identical particles. In this study, we used cryoelectron tomography to visualize the 3D structures of 110 individual virions of the X-31 (H3N2) strain of influenza A. The tomograms distinguish two kinds of glycoprotein spikes [hemagglutinin (HA) and neuraminidase (NA)] in the viral envelope, resolve the matrix protein layer lining the envelope, and depict internal configurations of ribonucleoprotein (RNP) complexes. They also reveal the stems that link the glycoprotein ectodomains to the membrane and interactions among the glycoproteins, the matrix, and the RNPs that presumably control the budding of nascent virions from host cells. Five classes of virions, four spherical and one elongated, are distinguished by features of their matrix layer and RNP organization. Some virions have substantial gaps in their matrix layer (“molecular fontanels”), and others appear to lack a matrix layer entirely, suggesting the existence of an alternative budding pathway in which matrix protein is minimally involved.
Seizures and enhanced cortical GABAergic inhibition in two mouse models of human autosomal dominant nocturnal frontal lobe epilepsy
Authors: Klaassen Alwin , Glykys Joseph , Maguire Jamie , Labarca Cesar , Mody Istvan , Boulter Jim
Published: December 2006

Selected mutations in the human α4 or β2 neuronal nicotinic acetylcholine receptor subunit genes cosegregate with a partial epilepsy syndrome known as autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). To examine possible mechanisms underlying this inherited epilepsy, we engineered two ADNFLE mutations (
Chrna4
S252F
and
Chrna4
+L264
) in mice. Heterozygous ADNFLE mutant mice show persistent, abnormal cortical electroencephalograms with prominent delta and theta frequencies, exhibit frequent spontaneous seizures, and show an increased sensitivity to the proconvulsant action of nicotine. Relative to WT, electrophysiological recordings from ADNFLE mouse layer II/III cortical pyramidal cells reveal a >20-fold increase in nicotine-evoked inhibitory postsynaptic currents with no effect on excitatory postsynaptic currents. i.p. injection of a subthreshold dose of picrotoxin, a use-dependent γ-aminobutyric acid receptor antagonist, reduces cortical electroencephalogram delta power and transiently inhibits spontaneous seizure activity in ADNFLE mutant mice. Our studies suggest that the mechanism underlying ADNFLE seizures may involve inhibitory synchronization of cortical networks via activation of mutant α4-containing nicotinic acetylcholine receptors located on the presynaptic terminals and somatodendritic compartments of cortical GABAergic interneurons.
The G534E polymorphism of the gene encoding the factor VII–activating protease is associated with cardiovascular risk due to increased neointima formation
Authors: Sedding Daniel , Daniel Jan-Marcus , Muhl Lars , Hersemeyer Karin , Brunsch Hannes , Kemkes-Matthes Bettina , Braun-Dullaeus Ruediger C. , Tillmanns Harald , Weimer Thomas , Preissner Klaus T. , Kanse Sandip M.
Published: December 2006

The G534E polymorphism (Marburg I [MI]) of factor VII–activating protease (FSAP) is associated with carotid stenosis and cardiovascular disease. We have previously demonstrated that FSAP is present in atherosclerotic plaques and it is a potent inhibitor of vascular smooth muscle proliferation and migration in vitro. The effect of wild-type (WT)- and MI-FSAP on neointima formation in the mouse femoral artery after wire-induced injury was investigated. Local application of WT-FSAP led to a 70% reduction in the neointima formation, and this effect was dependent on the protease activity of FSAP. MI-FSAP did not inhibit neointima formation in vivo. This is due to a reduced proteolytic activity of MI-FSAP, compared to WT-FSAP, toward platelet-derived growth factor BB, a key mediator of neointima development. The inability of MI-FSAP to inhibit vascular smooth muscle accumulation explains the observed linkage between the MI-polymorphism and increased cardiovascular risk. Hence, FSAP has a protective function in the vasculature, and analysis of MI polymorphism is likely to be clinically relevant in restenosis.
APOBEC3G/3F mediates intrinsic resistance of monocyte-derived dendritic cells to HIV-1 infection
Authors: Pion Marjorie , Granelli-Piperno Angela , Mangeat Bastien , Stalder Romaine , Correa Rafael , Steinman Ralph M. , Piguet Vincent
Published: December 2006

HIV-1 infects immature dendritic cells (iDCs), but infection is inefficient compared with activated CD4+ T cells and only involves a small subset of iDCs. We analyzed whether this could be attributed to specific cellular restrictions during the viral life cycle. To study env-independent restriction to HIV-1 infection, we used a single-round infection assay with HIV-1 pseudotyped with vesicular stomatitis virus G protein (HIV-VSVG). Small interfering RNA–mediated depletion of APOBEC3G/3F (A3G/3F), but not TRIM5α, enhanced HIV-1 infection of iDCs, indicating that A3G/3F controls the sensitivity of iDCs to HIV-1 infection. Furthermore, sequences of HIV reverse transcripts revealed G-to-A hypermutation of HIV genomes during iDC infection, demonstrating A3G/3F cytidine deaminase activity in iDCs. When we separated the fraction of iDCs that was susceptible to HIV, we found the cells to be deficient in A3G messenger RNA and protein. We also noted that during DC maturation, which further reduces susceptibility to infection, A3G levels increased. These findings highlight a role for A3G/3F in explaining the resistance of most DCs to HIV-1 infection, as well as the susceptibility of a fraction of iDCs. An increase in the A3G/3F-mediated intrinsic resistance of iDCs could result in a block of HIV infection at its mucosal point of entry.
Vanin-1 licenses inflammatory mediator production by gut epithelial cells and controls colitis by antagonizing peroxisome proliferator-activated receptor γ activity
Authors: Berruyer Carole , Pouyet Laurent , Millet Virginie , Martin Florent M. , LeGoffic Aude , Canonici Alexandra , Garcia Stéphane , Bagnis Claude , Naquet Philippe , Galland Franck
Published: December 2006

Colitis involves immune cell–mediated tissue injuries, but the contribution of epithelial cells remains largely unclear. Vanin-1 is an epithelial ectoenzyme with a pantetheinase activity that provides cysteamine/cystamine to tissue. Using the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-colitis model we show here that Vanin-1 deficiency protects from colitis. This protection is reversible by administration of cystamine or bisphenol A diglycidyl ether, a peroxisome proliferator-activated receptor (PPAR)γ antagonist. We further demonstrate that Vanin-1, by antagonizing PPARγ, licenses the production of inflammatory mediators by intestinal epithelial cells. We propose that Vanin-1 is an epithelial sensor of stress that exerts a dominant control over innate immune responses in tissue. Thus, the Vanin-1/pantetheinase activity might be a new target for therapeutic intervention in inflammatory bowel disease.
Wrist and Finger Drop in Myasthenia Gravis
Authors: Nicolle Michael W
Published: December 2006

Abstrct

Several years after the diagnosis of myasthenia gravis, a 40-year-old man developed weakness of the right hand grip and as a result lost his job. After obtaining a second job, he developed weakness of his left hand, losing this job as well. He consulted a series of physicians, including neurologists, and a variety of diagnoses for his hand weakness was considered. The neurologic examination showed distal weakness of the left hand, especially involving wrist and finger extension. Electrophysiologic studies showed significant decrement after repetitive nerve stimulation of the left, but not right, radial nerve. Although uncommon, distal and strikingly asymmetric weakness can be a manifestation of myasthenia gravis.
A novel wheat gene encoding a putative chitin‐binding lectin is associated with resistance against Hessian fly
Authors: GIOVANINI MARCELO P. , SALTZMANN KURT D. , PUTHOFF DAVID P. , GONZALO MARTIN , OHM HERBERT W. , WILLIAMS CHRISTIE E.
Published: December 2006

The gene‐for‐gene interaction triggering resistance of wheat against first‐instar Hessian fly larvae utilizes specialized defence response genes not previously identified in other interactions with pests or pathogens. We characterized the expression of Hfr‐3, a novel gene encoding a lectin‐like protein with 68–70% identity to the wheat germ agglutinins. Within each of the four predicted chitin‐binding hevein domains, the HFR‐3 translated protein sequence contained five conserved saccharide‐binding amino acids. Quantification of Hfr‐3 mRNA levels confirmed a rapid response and gradual increase, up to 3000‐fold above the uninfested control in the incompatible interaction 3 days after egg hatch. Hfr‐3 mRNA abundance was influenced by the number of larvae per plant, suggesting that resistance is localized rather than systemic. In addition, Hfr‐3 was responsive to another sucking insect, the bird cherry‐oat aphid, but not to fall armyworm attack, wounding or exogenous application of methyl jasmonate, salicylic acid or abscisic acid. Western blot analysis demonstrated that HFR‐3 protein increased in parallel to mRNA levels in crown tissues during incompatible interactions. HFR‐3 protein was detected in both virulent and avirulent larvae, indicating ingestion. Anti‐nutritional proteins, such as lectins, may be responsible for the apparent starvation of avirulent first‐instar Hessian fly larvae during the initial few days of incompatible interactions with resistant wheat plants.
The provision of communication aids to children in England: an analysis of applications to the Communication Aids Project
Authors: Clarke M. T. , Donlan C. , Lister C. , Wright J. , Newton C. , Cherguit J.
Published: December 2006

Background  Children who experience difficulties in face‐to‐face interaction, understanding language and developing literacy can benefit from the provision of communication aids such as speech synthesizers and specialist software applications that support their social participation and learning. The Communication Aids Project (CAP) was a national initiative by the Department for Education and Skills in England, aimed at supporting and developing the provision of communication aids to children. This paper presents an analysis of the number and type of applications to CAP. In so doing, the paper begins to explore how the need for communication aids might be understood in England.

Methods  The analysis was carried out on a database of 3060 anonymized records, representing applications to CAP between January 2002 and January 2004.

Results  Applications to CAP were made on behalf of children with a broader range of disabilities than might be assumed, including a relatively high proportion of children with autistic spectrum disorder. Rates of application to CAP varied in line with Local Education Authority population size [e.g. total pupils, total pupils with special educational needs (SEN)], rather than indicators of regional variation in SEN provision (e.g. proportion of population identified as having SEN).

Conclusions  Within a context of changing services to children in England and increasing emphasis on the plurality and contestability of services, the relevance of these findings for service providers and service commissioners is discussed.
Internet addiction among Chinese adolescents: prevalence and psychological features
Authors: Cao F. , Su L.
Published: December 2006

Background  To investigate the prevalence of Internet addiction among Chinese adolescents and to explore the psychological features associated with Internet addiction.

Methods  A total of 2620 high school students from four high schools in Changsha City were surveyed using Diagnostic Questionnaire for Internet Addiction (YDQ), Eysenck Personality Questionnaire (the edition for children, EPQ), Time Management Disposition Scale (TMDS) and Strengths and Difficulties Questionnaire (SDQ). The mean age of whole sample was 15.19 years (ranging from 12 years to 18 years). According to the modified YDQ criteria by Beard, 64 students who were diagnosed as Internet addiction (the mean age: 14.59 years) and 64 who were diagnosed as being normal in Internet usage (the mean age: 14.81 years) were included in a case–control study.

Results  The rate of Internet use among the surveyed adolescents was 88%, among which the incidence rate of Internet addiction was 2.4%. The Internet addiction group had significantly higher scores on the EPQ subscales of neuroticism, psychoticism, and lie than the control group (P < 0.05). The Internet addiction group scored lower than the control group on the TMDS subscales of sense of control over time, sense of value of time, and sense of time efficacy (P < 0.05). Compared with the control group, the Internet addiction group had also significantly higher scores on the SDQ subscales of emotional symptoms, conduct problems, hyperactivity, total difficulties and lower scores on the subscale of prosocial behaviours (P < 0.05).

Conclusions  The present study suggests that Internet addiction is not rare among Chinese adolescents. In addition, adolescents with Internet addiction possess different psychological features when compared with those who use the Internet less frequently.
The self‐concept of children and adolescents with neurofibromatosis type 1
Authors: Barton B. , North K.
Published: December 2006

Background  Neurofibromatosis type 1 (NF1) is a genetic disorder associated with cognitive deficits, learning problems, medical complications and cosmetic disfigurement. Despite the wide‐ranging impact of NF1, very few studies have examined the psychosocial adjustment of individuals with NF1, and in particular, self‐concept. The aims of this study were threefold: (i) to examine the self‐concept of children and adolescents with NF1; (ii) to compare the self‐concept of children with NF1 (NF1 only), children with NF1 and learning difficulties [NF1 + LA (low achievement)], and children with NF1 and attention deficit hyperactivity disorder (ADHD) (NF1 + ADHD); and (iii) to examine the academic self‐concept of these three groups relative to objective criteria – academic achievement and teacher ratings of academic competence.

Methods  Measures of self‐concept, academic achievement and intelligence were administered to 49 children and 26 adolescents with NF1. Parents and teachers completed behavioural rating scales.

Results  The majority of children and adolescents with NF1 reported positive global self‐concept, with some exceptions on specific domains. Children and adolescents with NF1 reported significantly poorer self‐concept for physical abilities. Adolescents also reported significantly poorer self‐concept for mathematics and general self when compared with normative mean values. Clinical severity of NF1 was not a significant predictor of self‐concept for physical appearance or physical abilities. Despite a significant difference between NF1 only, NF1 + LA and NF1 + ADHD groups on measures of academic achievement and teacher ratings of academic competence, there was no significant difference between the groups for academic domains of self‐concept, or any other domain of self‐concept. All three groups reported inflated academic self‐perceptions relative to objective criteria.

Conclusion  Children and adolescents with NF1 are most likely to develop negative self‐concepts about their physical and sporting abilities. Inflated academic self‐perceptions are discussed in light of the positive illusory bias, which may serve as an adaptive or protective function.
A nanoengine for gliding motility
Authors: Jensen Grant
Published: December 2006

The terminal organelle present in some mycoplasma species is a very large, complex, flexible structure involved in cell adherence, motility and cell division. In this issue of Molecular Microbiology, Hasselbring and Krause report on a mutant in which the terminal organelle is only weakly connected to the rest of the cell. ‘Run‐away’ terminal organelles first stretch the cells, then break away and continue moving independently for more than half an hour. This remarkable observation proves that the ‘nanoengine’ driving motility is indeed associated with the terminal organelle, and opens up new opportunities for dissecting and understanding its mechanism.
The Saccharomyces cerevisiae Crs5 Metallothionein metal‐binding abilities and its role in the response to zinc overload
Authors: Pagani Ayelen , Villarreal Laura , Capdevila Mercè , Atrian Sílvia
Published: December 2006

Crs5 is a Saccharomyces cerevisiae Metallothionein (MT), non‐homologous to the paradigmatic Cu‐thionein Cup1. Although considered a secondary copper‐resistance agent, we show here that it determines survival under zinc overload in a CUP1‐null background. Its overexpression prevents the deleterious effects exhibited by CUP1‐CRS5‐null cells when exposed to combined Zn/Cu, as it does the mouse MT1 Zn‐thionein, but not Cup1. The detailed characterization of Crs5 in vivo and in vitro Zn(II)‐, Cd(II)‐ and Cu(I)‐binding abilities fully supports its resemblance to mammalian MTs. Hence, Crs5 exhibits a good divalent metal‐binding ability, yielding homometallic, highly chiral and stable Zn and Cd complexes when expressed in media enriched with these metal ions. In Cu‐supplemented cultures, heterometallic Zn,Cu complexes are recovered, unless aeration is kept to a minimum. These features define a Crs5 dual metal‐binding behaviour that is significantly closer to Zn‐thioneins than to Cu‐thioneins. Protein sequence similarities fully support these findings. Overall, a Crs5 function in global metal cell homeostasis, based on its Zn‐binding features, is glimpsed. The comparative evaluation of Crs5 in the framework of MT functional differentiation and evolution allows its consideration as a representative of the primeval eukaryotic forms that progressively evolved to give rise to the Zn‐thionein lineage.
Characterization of the Thermotoga maritima chemotaxis methylation system that lacks pentapeptide‐dependent methyltransferase CheR:MCP tethering
Authors: Perez Eduardo , Stock Ann M.
Published: December 2006

Sensory adaptation in bacterial chemotaxis is mediated by covalent modifications of specific glutamate and glutamine residues within the cytoplasmic domains of methyl‐accepting chemotaxis proteins (MCPs). In Escherichia coli and Salmonella enterica, efficient methylation of MCPs depends on the localization of methyltransferase CheR to MCP clusters through an interaction between the CheR β‐subdomain and a pentapeptide sequence (NWETF or NWESF) at the C‐terminus of the MCP. In vitro methylation analyses utilizing S. enterica and Thermotoga maritima CheR proteins and MCPs indicate that MCP methylation in T. maritima occurs independently of a pentapeptide‐binding motif. Kinetic and binding measurements demonstrate that despite efficient methylation, the interaction between T. maritima CheR and T. maritima MCPs is of relatively low affinity. Comparative protein sequence analyses of CheR β‐subdomains from organisms having MCPs that contain and/or lack pentapeptide‐binding motifs identified key similarities and differences in residue conservation, suggesting the existence of two distinct classes of CheR proteins: pentapeptide‐dependent and pentapeptide‐independent methyltransferases. Analysis of MCP C‐terminal ends showed that only ∼10% of MCPs contain a putative C‐terminal binding motif, the majority of which are restricted to the different proteobacteria classes (α, β, γ, δ). These findings suggest that tethering of CheR to MCPs is a relatively recent event in evolution and that the pentapeptide‐independent methylation system is more common than the well‐characterized pentapeptide‐dependent methylation system.
Burkholderia mallei expresses a unique lipopolysaccharide mixture that is a potent activator of human Toll‐like receptor 4 complexes
Authors: Brett Paul J. , Burtnick Mary N. , Snyder D. Scott , Shannon Jeffrey G. , Azadi Parastoo , Gherardini Frank C.
Published: December 2006

Burkholderia mallei, the aetiologic agent of glanders, causes a variety of illnesses in animals and humans ranging from occult infections to acute fulminating septicaemias. To better understand the role of lipopolysaccharide (LPS) in the pathogenesis of these diseases, studies were initiated to characterize the structural and biological properties of lipid A moieties expressed by this organism. Using a combination of chemical analyses and MALDI‐TOF mass spectrometry, B. mallei was shown to express a heterogeneous mixture of tetra‐ and penta‐acylated lipid A species that were non‐stoichiometrically substituted with 4‐amino‐4‐deoxy‐arabinose residues. The major penta‐acylated species consisted of bisphosphorylated d‐glucosamine disaccharide backbones possessing two amide linked 3‐hydroxyhexadecanoic acids, two ester linked 3‐hydroxytetradecanoic acids [C14:0(3‐OH)] and an acyloxyacyl linked tetradecanoic acid, whereas, the major tetra‐acylated species possessed all but the 3′‐linked C14:0(3‐OH) residues. In addition, although devoid of hexa‐acylated species, B. mallei LPS was shown to be a potent activator of human Toll‐like receptor 4 complexes and stimulated human macrophage‐like cells (THP‐1 and U‐937), monocyte‐derived macrophages and dendritic cells to produce high levels of TNF‐α, IL‐6 and RANTES. Based upon these results, it appears that B. mallei LPS is likely to play a significant role in the pathogenesis of human disease.
Economic impact of Turnip mosaic virus, Cauliflower mosaic virus and Beet mosaic virus in three Kenyan vegetables
Authors: Spence N. J. , Phiri N. A. , Hughes S. L. , Mwaniki A. , Simons S. , Oduor G. , Chacha D. , Kuria A. , Ndirangu S. , Kibata G. N. , Marris G. C.
Published: December 2006

Screenhouse experiments conducted in Kenya showed that inoculation of cabbage seedlings with Turnip mosaic virus (TuMV), either alone, or in combination with Cauliflower mosaic virus (CaMV), reduced the number and weight of marketable harvested heads. When viruses were inoculated simultaneously, 25% of cabbage heads were non‐marketable, representing 20‐fold loss compared with control. By contrast, inoculation with CaMV alone had insignificant effects on cabbage yield. This suggests that TuMV is the more detrimental of these pathogens, and its management should be a priority. Early exposure to TuMV produced cabbages that were 50% lighter than non‐infected plants, but later infection was less damaging suggesting that controlling virus infection at the seedling stage is more important. TuMV was far less damaging to kale than it was to cabbage; although high proportions of TuMV‐inoculated kale plants showed symptoms (>90%), the marketability and quality of leaves were not significantly reduced, and no clear relationship existed between timing of infection and subsequent crop losses. Early inoculation of Swiss chard with Beet mosaic virus (BtMV) significantly impaired leaf quality (∼50% reduction in marketable leaf production), but the impact of disease was greatest in plants that had been inoculated at maturity, where average leaf losses were two and a half times those recorded in virus‐free plants. Disease‐management of BtMV in Swiss chard is important, therefore, not only at the seedling stage, but particularly when plants are transplanted from nursery to field.
Evaluation and characterization of resistance to fusarium head blight caused by Fusarium culmorum in UK winter wheat cultivars
Authors: Gosman N. , Bayles R. , Jennings P. , Kirby J. , Nicholson P.
Published: December 2006

Fusarium head blight (FHB) resistance of 50 cultivars from the National List of winter wheat cultivars approved for sale (or were undergoing trails for approval in 2003) in the UK was compared with 21 reference cultivars from continental Europe which had previously been characterized for resistance. Only three UK National List cultivars (Soissons, Spark and Vector) had stable resistance over trial sites that was significantly greater than that of the FHB susceptible cultivar Wizard. In addition, under moderate disease pressure, 21 of the National List cultivars had levels of the trichothecene mycotoxin deoxynivalenol (DON) above the proposed European Union limit of 1·25 ppm in grain. Surveys show that levels of FHB and DON in the UK crop are currently very low, however, should disease pressure increase for any reason, then an improvement in the overall levels of FHB resistance of UK winter wheat germplasm will be required. In order to infer the origin of resistance and to identify potentially novel resistance, allele sizes of microsatellite (simple sequence repeat, SSR) markers linked to quantitative trait loci (QTL) for FHB resistance were compared between the test cultivars and known, characterized resistance sources. The major FHB resistance QTL from the Chinese cv. Sumai‐3 (3BS, 5A and 6B), the Romanian cv. Fundulea F201R (1B and 5A) and the French cv. Renan (5AL) were screened with 17 SSRs. No National List cultivar had haplotypes similar to any of these QTL. However, the highly resistant German reference cultivar Petrus had an identical haplotype to cv. Fundulea F201R on 1B indicating that this cultivar has an allelic FHB resistance QTL at that location.
Foucault, Law, and Power: A Reassessment
Authors: Wickham Gary
Published: December 2006

After raising doubts about Foucault's approach to law‐power, in the light of various acts of religion‐inspired violence on and after 11 September 2001, a case is made against this approach, based on the charge that Foucault ties law far too tightly to what he calls negative power. He makes law part of juridico‐sovereignty power, a form of power he regards as outmoded, with an outmoded commitment to sovereignty and the state. It is argued that in attempting to separate law from what he sees as the positive power of modern governmentality, Foucault never understands law's role as a part of a crucial balance ‐ between political power, military power, the social, the cultural, the legal, and the economic ‐ a balance that tries to achieve both individual freedom and the security to enjoy that freedom. An alternative way of understanding law, and of understanding sovereignty and the state ‐ the state under the rule of law ‐ is presented as a much better route to an appreciation of law's part in the balance.
Fairness in Context
Authors: Adler Michael
Published: December 2006

This article is a contribution to the occasional series dealing with a major book that influenced the author. Previous contributors include Stewart Macaulay, John Griffith, William Twining, Carol Harlow, Geoffrey Bindman, Harry Arthurs, and André‐Jean Arnaud.

It describes the author's original encounter and subsequent dialogue with Bureaucratic Justice, by Jerry L. Mashaw which transformed his thinking about administrative justice and shaped the research he conducted over the next 25 years. The article assesses the strengths and weaknesses of Mashaw's approach to administrative justice, describes the author's attempts to modify and extend Mashaw's approach, outlines four case studies conducted by the author, and describes how the United Kingdom government has recently adopted an approach to administrative justice that is very similar to Mashaw's. The article concludes by considering the implications of Mashaw's approach for researchers and policy makers who wish to promote the idea that governments should attempt to treat people fairly.
THE IMPORTANCE OF REPUTATION IN AWARDING PUBLIC CONTRACTS
Authors: Doni Nicola
Published: December 2006

ABSTRACT*:  The main economic literature emphasizes that the efficiency of the awarding procedure depends on the contractual rules, especially those regarding firm's remuneration. In this work we show the existence of a reverse link: when the enforcement of contractual terms is imperfect, the rules of the awarding mechanism can help to improve the efficiency of the contractual relationship. In some circumstances, awarding rules based only on bids are not able to deal with the problem of opportunistic behaviour during the execution of the contract. Our model points out that the public administration can incentivize the contractor's fairness by considering not only competitors' bids, but also their different reputation.
CORRUPTION IN PUBLIC CONTRACTING AUCTIONS: THE ROLE OF TRANSPARENCY IN BIDDING PROCESSES
Authors: Boehm Frédéric , Olaya Juanita
Published: December 2006

ABSTRACT**:  The paper discusses corruption in public auctions and the role of transparency as a tool to prevent it. First, we analyse where corruption occurs, emphasizing the importance of considering the whole process, from deciding whether to contract‐out to implementing the contract. We then analyse the effects of corruption on public auctions and argue that corruption undermines their stated aims. Second, we discuss the ways transparency can mitigate corruption and possible trade‐offs regarding competition and efficiency. As an instrument, we focus on the Integrity Pact, a tool developed by Transparency International, and analyse cases in Argentina (school supplies) and Colombia (telecommunications), where transparency helped to prevent corruption and collusion and, furthermore, was able to enhance competition. We conclude with some policy implications.
LE RENOUVELLEMENT PÉRIODIQUE DES CONTRATS DE CONCESSION: LE CAS DES SERVICES DE L'EAU
Authors: Aubert Cécile , Bontems Philippe , Salanié François
Published: December 2006

RESUME**:  Le renouvellement régulier des contrats de concession apparaît nécessaire pour bénéficier de concurrence dans certains secteurs, comme l'eau. Nous décrivons les contrats et la règle de renouvellement optimaux dans ce contexte. Ils arbitrent entre les diminutions de coûts, en cas de changement de concessionnaire, et les incitations à investir à long terme du concessionnaire en place. La meilleure information du concessionnaire en place sur des éléments constituant une valeur commune de la concession est importante. Nous montrons que ses conséquences diffèrent fortement du cas des enchères de biens.
Ex Ante and Ex Post: What Does Rod Stewart Really Know Now?1
Authors: BLOCK WALTER , CARDEN ART , CARSON STEPHEN W.
Published: December 2006

Do we really know whether or not we have “maximized” utility, or do we just know that we are “happy” or “sad”? We argue that we can never know objectively whether or not utility has been maximized; however, people acting on a free market are sufficiently close to the decision as to be able to hazard a better guess about their opportunity costs than policy makers.
Protecting Education for the Poor in Times of Crisis: An Evaluation of a Scholarship Programme in Indonesia*
Authors: Sparrow Robert
Published: December 2006

This paper analyses the impact of an Indonesian scholarship programme, which was implemented in 1998 to preserve access to education for the poor during the economic crisis. Scholarships were targeted pro‐poor and the allocation process followed a decentralized design, involving both geographic and individual targeting. The identification strategy exploits this decentralized structure, relying on instrumental variables constructed from regional mistargeting at the initial phase of allocation. The programme has increased enrolment, especially for primary school‐aged children from poor rural households. Moreover, the scholarships seem to have assisted households in smoothing consumption during the crisis, relieving pressure on households’ investments in education and utilization of child labour.
Scalar Narratives in Bilbao: A Cultural Politics of Scales Approach to the Study of Urban Policy
Authors: GONZÁLEZ SARA
Published: December 2006

In this article I explore how theoretical metaphors about the contemporary rescaling of the capitalist economy are used by local policy actors to justify an entrepreneurial urban policy. I develop a new theoretical concept (scalar narrative), suggest an analytical approach (cultural politics of scales) and give evidence of a particular case (Bilbao). The article is structured in the following way. First, I briefly review the literature on politics of scales and contribute to the debate with an approach that incorporates elements from cultural political economy and interpretative policy analysis. Within this approach I mobilize the concept of ‘scalar narrative’ that has already been suggested in the literature but not fully explored. I then put this approach into practice with a particular case study, Bilbao, a city in the north of Spain, which has recently gone through extensive urban regeneration, where I describe the appropriation of three scalar narratives by the policymakers. To show this I draw from empirical work done in Bilbao that looks at statutory and strategic planning documents as well as urban marketing literature and interviews with key informants.
Mumbai’s Mysterious Middle Class
Authors: NIJMAN JAN
Published: December 2006

Mumbai forms the décor to an interesting set of relationships among economic liberalization, globalization, class restructuring and an unprecedented housing construction boom. The much talked about new Indian middle class is primarily an urban phenomenon and seems nowhere more salient than in India’s commercial capital and largest city. This article seeks to undo some of the mysteries that surround the new middle class: how it can be empirically defined, whether and how it is growing, how class restructuring in Mumbai conforms (or not) to Western arguments about social polarization, and how any such class restructuring can best be explained. The empirical analysis employs existing data from various sources on income and consumption in Mumbai (and India at large) and reports on selected findings from a recent survey by the author on housing, class and upward mobility among households in newly constructed homes in Greater Mumbai. Data on the distribution of household incomes show that the upper‐middle income classes have grown relative to the total, that the lower‐middle income classes have shrunk, and that the ranks of the poor have expanded slightly. Survey data among new home buyers in Mumbai suggest little upward mobility. Discourse about the ‘new middle class’ tends to focus on consumption rather than income and additional findings indicate that much of the growth in consumption is credit‐based.
Planning for Peace in Contested Space
Authors: MORRISSEY MIKE , GAFFIKIN FRANK
Published: December 2006

This article explores the debate about contested space in urban policy and planning. Beginning with a review of key concepts and theories, it proceeds to identify models for understanding such spaces and for effective public intervention. It takes a case study of Belfast, on which there is substantial literature and data, to explore whether the recent history of this city can contribute to the debate about the role of urban planning and policy in contested space. Finally, it suggests that the Belfast experience indicates the need for a broader framework of intervention than is possible within a purely planning paradigm.
Causes and Consequences of the Relation Between Split‐Adjusted Share Prices and Subsequent Stock Returns
Authors: Brown William D. , Pfeiffer Ray J.
Published: December 2006

Abstract:  In this manuscript, we document and explain an empirical artifact — a persistent and substantial negative relation between split‐adjusted share prices and subsequent stock returns — that has potentially important ramifications for capital markets research design. This relation pervades all commonly‐used commercial databases and is insensitive to the choice of database used for either prices or returns. We investigate four potential causes of the empirical regularity: survivorship bias, asymmetric returns to low‐priced stocks, extreme returns, and the effects of stock‐split adjustments on portfolio classifications. We find that survivorship bias accounts for approximately half of the returns documented to a share‐price‐based hedge strategy and that re‐classifications caused by stock split adjustments account for substantially all of the remaining returns. We do not find that controlling for either low‐priced stocks or extreme returns is effective in purging the data of the empirical price artifact. These findings and our explanations thereof are important, as they show that there are potentially troublesome consequences of using share price as a deflator in markets‐based research. In particular, we note and illustrate cause for concern when interpreting associations between share‐price‐scaled variables and subsequent returns as evidence of market inefficiency.
Initial Crisis Agent‐Response Impact Syndrome (ICARIS)
Authors: Hensgen Tobin , Desouza Kevin C. , Durland Maryann
Published: December 2006

There has been a dramatic shift in attitude among organizations regarding the probabilities of crisis occurring. Once crises were considered the domain of the contingency management team that sought the fastest means to recovery, now the entire organization is compelled to take steps intended to mitigate conditions leading to a crisis. In this paper, the authors consider the organization's ‘first responders’ i.e., those who become involuntarily placed in the decision making process because they are the first to become aware of the conditions which indicate impending crisis simply because they are ‘on scene.’ As agents of the organization, these persons will make initial decisions well before the implementation of any formal contingency plan and because their decisions will be based on incomplete assumptions, they are likely to be in error. The impact of these initial crisis‐agent responses can cause irreparable damage to the organization, to the individuals within the organization, and to the surrounding environment. This tendency toward error is referred to as the initial crisis‐agent response impact syndrome: ICARIS. Exercising a program that prepares all employees for the initial decisions that need to be made at the moment of crisis can mitigate problems related to this issue.
Wielding a Double‐Edged Sword: The Use of Inquiries at Times of Crisis
Authors: Resodihardjo Sandra L.
Published: December 2006

Inquiries are often seen as a useful tool to deal with a crisis. By installing an inquiry, crisis managers show that they are in control of the crisis response. Moreover, they can hope that by the time the inquiry publishes its report a new topic has caught the attention of media and Parliament and reform measures do not need to be taken to end the crisis (McConnell, 2003). Following a series of riots in British prisons in 1990, the Home Secretary installed an inquiry. By the time the Woolf inquiry published its report, media and Parliamentary attention for the British Prison Service was indeed dwindling. Normally, this low level of attention would provide political actors room to end the crisis with mere small measures and no need for reform. Yet in this case, and contrary to the dominant view on how inquiries influence the crisis management process, the Woolf inquiry provided an unexpected impetus to the crisis managing process, resulting in institutional reform of the British Prison Service (or to be more accurate, the Prison Service of England and Wales). This article shows how an inquiry can have an unexpected effect for political actors managing the crisis by introducing a new way of defining the problem at hand.
The Importance of Governance in Risk Reduction and Disaster Management
Authors: Ahrens Joachim , Rudolph Patrick M.
Published: December 2006

This paper identifies institutional failure as the root cause for underdevelopment and susceptibility to disasters and explores their interdependent relationship. It is demonstrated that only if a country's governance structure enables the implementation and enforcement of public policies conducive to a country's economic and social development can sustainable livelihoods be achieved and susceptibility to disasters be reduced. Accountability, participation, predictability and transparency are identified as the key features of a governance structure that fosters development and supports risk reduction.