bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal and spatial patterns of sea level in inland basins: Recent events in the Aral Sea
Authors: Stanev E. V. , Peneva E. L. , Mercier F.
Published: August 2004

We demonstrate in this paper that satellite altimeter data resolve the drop in the Aral Sea level during 1993–2000 of about 0.6 m per year resulting in a change of surface area from 35000 to 22000 km2 and volume from 270 to 130 km3. The sudden drop in the sea level of the Northern basin on 04.21.1999 resulting from dam break‐up is also clearly resolved. The temporal and spatial variability of sea level reveals response patterns which are characteristic for friction dominated shallow sea dynamics. The combination of salinity and sea‐level data enables to identify the major events of environmental transition, which are associated with the temporal variability in the total salt content: (1) a peak in 1993–1994, and (2) an increasing trend in the last decade. These events are indicative of an increase in the discharge of ground water, but could also reveal overestimated salinity estimates from recent observations.
Anomalously high levels of NOx in the polar upper stratosphere during April, 2004: Photochemical consistency of HALOE observations
Authors: Natarajan Murali , Remsberg Ellis E. , Deaver Lance E. , Russell James M.
Published: August 2004

Significant perturbations to the odd nitrogen mixing ratios in the high latitude upper stratosphere are seen in the Halogen Occultation Experiment (HALOE) data during April, 2004. Sunrise observation of 99.1 ppbv of NOx (NO + NO2) at 68N represents the largest NOx measured near 2 hPa. Examination of potential vorticity maps indicates that these high NOx mixing ratios correspond to measurements made within the polar vortex. Photochemical model results show large reductions in ozone in response to the enhancements in NOx, and HALOE ozone data are in good agreement with the model results. Probable cause of these anomalous values of NOx in the upper stratosphere is the enhanced production of NO in the high latitude upper mesosphere/thermosphere regions due to the powerful solar flares and the associated energetic particle precipitation that took place during October–November, 2003, followed by downward transport in the polar winter.
El Niño suppresses Antarctic warming
Authors: Bertler Nancy A. N. , Barrett Peter J. , Mayewski Paul A. , Fogt Ryan L. , Kreutz Karl J. , Shulmeister James
Published: August 2004

Here we present new isotope records derived from snow samples from the McMurdo Dry Valleys, Antarctica and re‐analysis data of the European Centre for Medium‐Range Weather Forecasts (ERA‐40) to explain the connection between the warming of the Pacific sector of the Southern Ocean [Jacka and Budd, 1998; Jacobs et al., 2002] and the current cooling of the terrestrial Ross Sea region [Doran et al., 2002a]. Our analysis confirms previous findings that the warming is linked to the El Niño Southern Oscillation (ENSO) [Kwok and Comiso, 2002a, 2002b; Carleton, 2003; Ribera and Mann, 2003; Turner, 2004], and provides new evidence that the terrestrial cooling is caused by a simultaneous ENSO driven change in atmospheric circulation, sourced in the Amundsen Sea and West Antarctica.
Nonuniqueness of inverted core‐mantle boundary flows and deviations from tangential geostrophy
Authors: Pais M. A. , Oliveira O. , Nogueira F.
Published: August 2004

The task of finding a flow at the top of the core that fits geomagnetic observations at the Earth's surface is an underdetermined problem. Weighted regularized least squares together with the tangential geostrophy hypothesis strongly constrain the flow, inhibiting both medium‐ to small‐scale flow features from emerging and low‐latitude currents from crossing the geographic equator. In this study, we solve the inverse problem in the frozen flux approximation, using a weak regularization and alleviating the tangential geostrophy constraint. Two classes of solutions are found (I and II), both fitting the data within the errors but nonetheless showing very distinct features. Using, as a further criterion, the ability of the flow solutions to reproduce the decade variations of the length of day does not allow us, in general, to give a clear preference to one class over another. For typical flows from the whole set of solutions described above, we identify the regions on the core‐mantle boundary (CMB) where tangential geostrophy is violated, and we quantify those deviations. Assuming that they are due to Lorentz forces acting on the fluid, we compute preliminary charts of electrical density currents (J) on the CMB, consistent with the frozen flux and insulating mantle hypotheses. The most pronounced features in these charts are concentrated over the hemisphere roughly centered beneath the Atlantic Ocean. In light of thermodynamical arguments, class II flows seem closer to real surface core flows. We compute an upper limit JRMS ≈ 0.4 A/m2 for geomagnetically “visible” density currents related to these flows.
High‐resolution imaging of lowermost mantle structure under the Cocos plate
Authors: Thomas Christine , Garnero Edward J. , Lay Thorne
Published: August 2004

Broadband seismic shear waves are analyzed to investigate the fine‐velocity structure in the lowermost mantle beneath the Cocos plate, a region where previous studies have indicated the presence of a shear velocity increase about 200–300 km above the core‐mantle boundary. Data from 14 South American earthquakes recorded at California broadband networks provide dense ray path sampling of the lowermost mantle in an approximately 700 km long north‐south corridor, roughly 150 km wide. Application of a simplified seismic migration method that uses a homogeneous background velocity model suggests topography of the previously imaged positive impedance jump, varying in depth from north to south by as much as 150 km, with a weakly reflecting transition zone in between. The migration approach enables examination of small‐scale spatial variations and out‐of‐plane scattering effects. Topography of the discontinuity may account for observed variations in the amplitude of reflected arrivals or there may be lateral variations in the velocity contrast across the boundary. Lateral variations of the shear velocity structure within the D″ layer may produce some apparent topography in the discontinuity image, but any such volumetric structure is not yet well enough determined to incorporate in the migration. A localized negative impedance contrast reflector or scatterer is imaged at depths about 100 km below the positive reflector in the northern portion of the study area. Several scenarios can explain these results, including (1) a slab that reaches the lowermost mantle, (2) the birth of an upwelling beneath a recumbent slab, or (3) chemical layering in this region.
A modeling study of aqueous production of dicarboxylic acids: 2. Implications for cloud microphysics
Authors: Ervens Barbara , Feingold Graham , Clegg Simon L. , Kreidenweis Sonia M.
Published: August 2004

We estimate the effect of selected small organic species, present in aerosol particles as internal mixtures with sulphate, on cloud microphysical properties using a numerical model. The initial aerosol compositions were motivated by a prior model study in which it was shown that under certain conditions, small dicarboxylic acids, primarily oxalic and glutaric acids, can be efficiently formed via aqueous chemical processes in clouds and remain in the aerosol fraction upon drop evaporation. The simulations performed here separate the effects of the growth in particle mass via in‐cloud oxidation from the change in composition of the resulting aerosol. Although the sulphate/organic mixed particles are somewhat less hygroscopic than pure ammonium sulphate, their activity as cloud condensation nuclei in a simulated constant updraft is similar, and the main influence of prior cloud processing of particles arises from the change in total mass and size distribution. We also performed a separate series of simulations initialized with an aerosol consisting of 90% adipic acid/10% ammonium sulphate, chosen to represent a lower limit on the mixed‐particle hygroscopic behavior. If only the reduced solubility of the mixture, relative to that of pure sulphate aerosol, is considered, the drop number concentration is suppressed by up to 50%, depending on the choice of initial conditions. However, the suppression of surface tension due to the presence of the organics, modeled using two different approaches, leads to a compensating effect that can result in little net change to the drop concentration relative to that for the pure sulphate aerosol.
Theoretical model of the electric field produced by charged particles in windblown sand flux
Authors: Zheng Xiaojing , He Lihong , Zhou Youhe
Published: August 2004

Taking into account the coupled interactions among wind velocity, sand movement, and the electric field, we develop a general theoretical model for calculating the electric fields produced by charged sand particles in the three sand movement types, saltation, suspension and creep, quantifying the electric field of a point charge by Coulomb's law. The numerical results of the electric field are in good agreement with both the field data and the wind tunnel experimental results. The profile of the electric field intensity produced by charged particles in windblown sand flux is quantitatively analyzed in detail and compared with those generated by charged particles only in the saltation layer or in the creep layer. The results demonstrate that the profile of the electric field produced by charged particles in one sand movement type is different from that by those in other types and that the signs of the charge acquired by the particles also alter the features of the profile. Finally, the effects of the wind velocity and the charge of the windblown sand particles on the electric field intensity are discussed.
Unusual Glycosylation of 9-O-Benzylallosamizoline
Authors: Blattner Regine , Furneaux Richard H. , Gainsford Graeme J. , Wong Herbert
Published: August 2004

Intended selective glycosylation of the 9-O-benzyl ether 4 of allosamizoline 1 with a slight molar excess of 3,4,6-tri-O-acetyl-2-deoxy-2-trichloroacetamido-β-d-glucopyranosyl trichloroacetimidate 6 unexpectedly gave the di-O-glycosylated product 5 in high yield. In its crystalline form, this diglycoside adopts a conformation with the sugar rings extended away from the bicyclic unit of the aglycon and from each other. NMR spectroscopic features indicate that this conformation is not retained in solution.
Synthesis and Evaluation of a Molecularly Imprinted Polymer Selective to 2,4,6-Trichlorophenol
Authors: Schwarz Lachlan , Holdsworth Clovia I. , McCluskey Adam , Bowyer Michael C.
Published: August 2004

Molecularly imprinted polymers (MIPs) selective for the phenolic contaminant 2,4,6-trichlorophenol (2,4,6-TCP) were prepared and evaluated in three porogens of differing character (hexane, acetonitrile, dichloromethane). Rebinding of 2,4,6-TCP was found to be most effective in dichloromethane (imprinting factor: 13.2). Competitive binding studies performed against a range of close structural analogues showed a high preference for the target molecule, although partial recognition towards 2,4-dichlorophenol was also observed. Specificity was found to be dependent upon the presence of ring chlorine on the target, which suggested that these atoms participate in secondary binding interactions that are essential for successful recognition in the polymer cavity.
The Synthesis of Carbohydrate α-Amino Acids Utilizing the Corey - Link Reaction
Authors: Scaffidi Adrian , Skelton Brian W. , Stick Robert V. , White Allan H.
Published: August 2004

Various carbohydrate ketones (uloses) have been treated with chloroform under strongly basic conditions to yield trichloromethyl tertiary alcohols. These alcohols, when subjected to the conditions of the modified Corey–Link reaction (sodium azide and 1,8-diazabicyclo[5.4.0]undec-7-ene in methanol), generally gave the expected azido ester with complete stereocontrol. Subsequent transformations on these azido esters provided amino esters, azido acids, and, in one case, the amino acid. A similar sequence applied to a protected d-glucono-1,5-lactone was only partly successful.
Single-crystal X-ray structures are reported for 1,2:5,6-di-O-isopropylidene-3-C-trichloromethyl-α-d-allose, (3S)-3-C-azido-3-C-carboxy-3-deoxy-1,2:5,6-di-O-isopropylidene-α-d-ribo-hexose, 1,2:5,6-di-O-cyclohexylidene-3-C-trichloromethyl-α-d-gulose, (3S)-3-C-amino-1,2:5,6-di-O-cyclohexylidene-3-deoxy-3-C-methoxycarbonyl-α-d-xylo-hexose, methyl 2-O-benzyl-4,6-O-benzylidene-3-C-trichloromethyl-α-d-alloside, methyl (2S)-2-C-azido-3-O-benzyl-4,6-O-benzylidene-2-deoxy-2-C-methoxycarbonyl-α-d-arabino-hexoside, methyl 2,3-di-O-benzyl-6-deoxy-4-C-trichloromethyl-β-d-galactoside, 3,4,5,7-tetra-O-benzyl-1,1,1-trichloro-1-deoxy-α-d-gluco-hept-2-ulose, and 5-O-benzyl-1,2-O-isopropylidene-3-C-trichloromethyl-α-d-ribose.
Synthesis and Structure - Property Relations of Latexes Containing Graft Copolymers between Telechelic Polybutadiene and Dodecyl Methacrylate
Authors: Pham Binh T. T. , Gilbert Robert G. , Fellows Christopher M.
Published: August 2004

Latexes comprising novel copolymers were formed by second-stage emulsion polymerization of dodecyl methacrylate (DMA) onto a hydroxylated polybutadiene-based polyurethane prepolymer (PUD) as seed latex, with persulfate initiator. Morphology data from TEM imaging (including chemical fixation ultra-microtoming), glass transition temperature, dynamic mechanical analysis, and other mechanical-property data were all consistent with a system showing extensive grafting and compatibilization between the different polymeric components. Water adsorption and AFM measurements showed that samples with poorer film-forming properties had higher water sensitivity, greater mixing of the polymer phases, and poorer mechanical properties. These properties were related to a phase-inversion phenomenon occurring above a critical dodecyl methacrylate/prepolymer ratio. The compatibilization of the PUD and poly(DMA) given by these modifications resulted in a product with increased tackiness, although with a higher water sensitivity.
Molecular Encapsulation of Gases
Authors: Rudkevich Dmitry M. , Leontiev Alexander V.
Published: August 2004

The principles and techniques of molecular encapsulation, as applied to environmentally, biologically, and commercially important gases, are reviewed. The gases may be trapped within natural (clathrates, cyclodextrins) or synthetic (cryptophanes, carcerands, calixarenes) cavities. The physical and chemical features of the cavities are key to understanding which gases may be trapped and to what extent. These trapping materials possess a host of applications, from gas sensing and separation to acting as storage devices and microreaction vessels.
Role of the yeast acetyltransferase Mpr1 in oxidative stress: Regulation of oxygen reactive species caused by a toxic proline catabolism intermediate
Authors: Nomura Michiyo , Takagi Hiroshi
Published: August 2004

TheMPR1gene, which is found in the Σ1278b strain but is not present in the sequenced laboratory strain S288C, of the budding yeastSaccharomyces cerevisiaeencodes a previously uncharacterizedN-acetyltransferase that detoxifies the proline analogue azetidine-2-carboxylate (AZC). However, it is unlikely that AZC is a natural substrate of Mpr1 because AZC is found only in some plant species. In our search for the physiological function of Mpr1, we found thatmpr1-disrupted cells were hypersensitive to oxidative stresses and contained increased levels of reactive oxygen species (ROS). In contrast, overexpression ofMPR1leads to an increase in cell viability and a decrease in ROS level after oxidative treatments. These results indicate that Mpr1 can reduce intracellular oxidation levels. Becauseput2-disrupted yeast cells lacking Δ1-pyrroline-5-carboxylate (P5C) dehydrogenase have increased ROS, we examined the role of Mpr1 input2-disrupted strains. When grown on media containing urea and proline as the nitrogen source,put2-distrupted cells did not grow as well as WT cells and accumulated intracellular levels of P5C that were first detected in yeast cells and ROS. On the other hand,put2-disrupted cells that overexpressedMPR1had considerably lower ROS levels.In vitrostudies with bacterially expressed Mpr1 demonstrated that Mpr1 can acetylate P5C, or, more likely, its equilibrium compound glutamtate-γ-semialdehyde, at neutral pH. These results suggest that the proline catabolism intermediate P5C is toxic to yeast cells because of the formation of ROS, and Mpr1 regulates the ROS level under P5C-induced oxidative stress.
Recessive-interfering mutations in the gibberellin signaling gene
SLEEPY1
are rescued by overexpression of its homologue,
SNEEZY
Authors: Strader Lucia C. , Ritchie Siân , Soule Jonathan D. , McGinnis Karen M. , Steber Camille M.
Published: August 2004

This article reports the genetic interaction of two F-box genes,
SLEEPY1
(
SLY1
) and
SNEEZY
(
SNE
), in
Arabidopsis thaliana
gibberellin (GA) signaling. The
SLY1
gene encodes an F-box subunit of a Skp1-cullin-F-box (SCF) E3 ubiquitin ligase complex that positively regulates GA signaling. The
sly1-2
and
sly1-10
mutants have recessive, GA-insensitive phenotypes including delayed germination, dwarfism, reduced fertility, and overaccumulation of the DELLA proteins RGA (Repressor of ga1-3), GAI (GA-Insensitive), and RGL2 (RGA-Like 2). The DELLA domain proteins are putative transcription factors that negatively regulate GA signaling. The requirement for
SLY1
in GA-stimulated disappearance of DELLA proteins suggests that GA targets DELLA proteins for destruction via SCF
SLY1
-mediated ubiquitylation. Overexpression of
SLY1
in
sly1-2
and
sly1-10
plants rescues the recessive GA-insensitive phenotype of these mutants. Surprisingly, antisense expression of
SLY1
also suppresses these mutants. This result caused us to hypothesize that the
SLY1
homologue
SNE
can functionally replace
SLY1
in the absence of the recessive interfering
sly1-2
or
sly1-10
genes. This hypothesis was supported because overexpression of
SNE
in
sly1-10
rescues the dwarf phenotype. In addition to rescuing the
sly1-10
dwarf phenotype,
SNE
overexpression also restored normal RGA protein levels, suggesting that the SNE F-box protein can replace SLY1 in the GA-induced proteolysis of RGA. If the C-terminal truncation in the
sly1-2
and
sly1-10
alleles interferes with
SNE
rescue, we reasoned that overexpression of
sly1-2
might interfere with wild-type
SLY1
function. Indeed, overexpression of
sly1-2
in wild-type L
er
(Landsberg
erecta
) yields dwarf plants.
Multiple-stress analysis for isolation ofDrosophilalongevity genes
Authors: Wang Horng-Dar , Kazemi-Esfarjani Parsa , Benzer Seymour
Published: August 2004

Long-lived organisms tend to be more resistant to various forms of environmental stress. An example is theDrosophilalongevity mutant,methuselah, which has enhanced resistance to heat, oxidants, and starvation. To identify genes regulated by these three stresses, we made a cDNA library for each by subtraction of “unstressed” from “stressed” cDNA and used DNA hybridization to identify genes that are regulated by all three. This screen indeed identified 13 genes, some already known to be involved in longevity, plus candidate genes. Two of these,hsp26andhsp27, were chosen to test for their effects on lifespan by generating transgenic lines and by using the upstream activating sequence/GAL4 system. Overexpression of eitherhsp26orhsp27extended the mean lifespan by 30%, and the flies also displayed increased stress resistance. The results demonstrate that multiple-stress screening can be used to identify new longevity genes.
Functional immunomics: Microarray analysis of IgG autoantibody repertoires predicts the future response of mice to induced diabetes
Authors: Quintana Francisco J. , Hagedorn Peter H. , Elizur Gad , Merbl Yifat , Domany Eytan , Cohen Irun R.
Published: August 2004

One's present repertoire of antibodies encodes the history of one's past immunological experience. Can the present autoantibody repertoire be consulted to predict resistance or susceptibility to the future development of an autoimmune disease? Here, we developed an antigen microarray chip and used bioinformatic analysis to study a model of type 1 diabetes developing in nonobese diabetic male mice in which the disease was accelerated and synchronized by exposing the mice to cyclophosphamide at 4 weeks of age. We obtained sera from 19 individual mice, treated the mice to induce cyclophosphamide-accelerated diabetes (CAD), and found, as expected, that 9 mice became severely diabetic, whereas 10 mice permanently resisted diabetes. We again obtained serum from each mouse after CAD induction. We then analyzed, by using rank-order and superparamagnetic clustering, the patterns of antibodies in individual mice to 266 different antigens spotted on the chip. A selected panel of 27 different antigens (10% of the array) revealed a pattern of IgG antibody reactivity in the pre-CAD sera that discriminated between the mice resistant or susceptible to CAD with 100% sensitivity and 82% specificity (P= 0.017). Surprisingly, the set of IgG antibodies that was informative before CAD induction did not separate the resistant and susceptible groups after the onset of CAD; new antigens became critical for post-CAD repertoire discrimination. Thus, at least for a model disease, present antibody repertoires can predict future disease, predictive and diagnostic repertoires can differ, and decisive information about immune system behavior can be mined by bioinformatic technology. Repertoires matter.
Separate Spaces, Separate Outcomes? Neighbourhood Impacts on Minorities in Germany
Authors: Drever Anita I.
Published: August 2004

In both the German and US literature on ethnic neighbourhoods, there is considerable debate as to whether living amongst co-ethnics hinders or furthers the integration process for immigrants. Using the detailed data on immigrant integration in the German Socio-economic Panel in combination with zip-code-level data on minority concentration and neighbourhood income levels, the research tests the extent to which ethnic neighbourhoods are economically, socially and/or culturally isolated spaces in Germany. The findings indicate that, although general neighbourhood quality is lower for minorities living within ethnic neighbourhoods, these persons are no more culturally isolated from Germans than their counterparts living outside these areas. Further, minorities living within ethnic neighbourhoods appear no more likely to maintain ties to their country of origin culture than those living outside ethnic neighbourhoods. This suggests that the correlation between social and spatial integration, assumed in much of the immigrant integration literature, requires more careful scrutiny.
Remaking Local Governance through Community Participation? The Case of the UK Community Waste Sector
Authors: Luckin David , Sharp Liz
Published: August 2004

This article explores the role played by community sector organisations in terms of community participation and local governance. It focuses on organisations concerned with waste reduction, reuse and recycling-community waste projects. The current UK government has high expectations of the potential and actual role of the community sector in service delivery. To indicate how these expectations might be fulfilled, the article employs the local governance perspective and reviews claims made for the role played by the community sector in governance processes. The local linkages of community waste projects are then assessed through a 'policy-action' continuum. The article concludes that community waste projects provide significant opportunities for volunteer involvement in their activities. They also have significant impacts on waste governance, through service delivery and participation in related policy processes. However, suggestions that community sector organisations can represent the wishes of local people in policy processes should be treated with caution.
Estimation of the Tenants' Benefits Residing in Public Rental Housing with Unit Size Constraint in Korea
Authors: Kim In Joon , Kim Geun Yong , Yoon Juhyun
Published: August 2004

Hicksian income equivalent variation (EV) has often been used to measure tenants' benefits in evaluating public housing programmes. A number of papers have so far attempted to apply Hicksian EV under the implicit assumption of no constraint on unit size of public housing. As a result, overestimation of tenants' benefits probably occurs where unit size constraints exist, as in Korea's public housing programme. Thus, the purpose of the paper is to measure Hicksian EV with the constraint in unit size of public housing by formulating a revised Hicksian EV equation and comparing the result with constraint-free cases. It is found that Hicksian EV with constraint in unit size decreases relative to that of the constraint-free cases. The extent of EV decrease depends on the income elasticity of demand for housing and the difference between the optimum consumption of public housing under rent support (demand wanted) and the actual constraint of unit size (demand fulfilled).
Gibrat's Law and the Growth of Cities in Brazil: A Panel Data Investigation
Authors: Resende Marcelo
Published: August 2004

The paper builds on the results of Clark and Stabler who associated Gibrat's law on the independence of growth rate and city size with unit root tests. The paper proposes a direct test of the unit root hypothesis for firm size based on recently developed panel data unit root tests. The results for a sample of Brazilian cities over the period 1980-2000 favour Gibrat's law. Moreover, the results are robust when one considers sub-samples defined for different population sizes and age of municipality.
An alternative vision for the thoughtful teacher
Authors: Haggarty Linda
Published: August 2004

Book reviewed in this article:

Professional knowledge, professional lives: studies in education and change I. F. Goodson

Teaching in the knowledge society: education in the age of insecurity A. Hargreaves

The activist teaching profession J. Sachs
Are standards rising in English primary schools?
Authors: Tymms Peter
Published: August 2004

The officially reported impressive rises in standards in mathematics and English in primary schools since 1995 are challenged. The article looks at the increases from four different perspectives. First, the general pattern of change is considered. Secondly, the statutory test data are compared with the results from several different studies. These indicate a complex pattern with clear rises in standards, but not as strong as the official data suggest up to 2000. Since 2000 the official data have shown little change and this is largely confirmed by independent tests. Thirdly, the standard setting procedures are considered and mechanisms by which the observed patterns could have been produced are set out. Finally, parallels are drawn with the experience in Texas where an apparently remarkable set of data was shown to be largely illusory. A case is made for an independent body to be set up with the express and sole purpose of monitoring standards over time.
‘My mum would be as pleased as punch if I actually went, but my dad seems a bit more particular about it’: paternal involvement in young people's higher education choices
Authors: Brooks Rachel
Published: August 2004

Research on parental involvement in educational ‘choice’, as well as in educational processes more generally, has highlighted clear disparities between the close and active involvement of mothers and the more distant role of fathers. While this article does not question the broad patterns identified by such studies, it does suggest that, in some circumstances at least, fathers are both able and willing to become closely involved in decision‐making processes and to take on much of the ‘hard work’ of educational choice. Drawing on a longitudinal study of young people's higher education decision‐making processes, the article presents evidence of detailed paternal involvement. It then suggests that this apparent ‘anomaly’ can be explained by the mothers' and fathers' differential access to cultural and social capital; a lack of previous experience of active engagement with educational markets; and, in a few cases, young people's active resistance to the involvement of their mothers.
Primary pupils' experiences of different types of grouping in school
Authors: Hallam Susan , Ireson Judith , Davies Jane
Published: August 2004

There has been little research on pupils' experiences of ability grouping. This study aimed to explore the perceptions of primary‐aged pupils regarding the purpose and practice of within and between class ability grouping; their experiences of those practices; and how their attitudes to school, self‐perceptions and behaviour were affected. The study was undertaken in six primary schools adopting different combinations of grouping practices including streaming, setting, within‐class ability and mixed ability grouping. Six pupils, of high, moderate or low ability, mixed in gender, in each Key Stage 2 class were interviewed in each school. The findings showed that pupils were aware of how and why they were grouped and accepted the rationales provided. Attitudes towards school were not affected by grouping structures, but pupils' awareness of their place in the pecking order and the nature of teasing in the school were, although these were mediated by school ethos factors.
The researcher/interviewer in intercultural context: a social intruder!
Authors: Shah Saeeda
Published: August 2004

The search for improved understanding in cross‐cultural contexts is resulting in a correspondingly high increase in cross‐cultural studies in diverse fields and disciplines. Globalization, economic universalism and internationalization of technology, as well as increased international mobility, immigration and relocation accelerated by the communication explosion, are drawing the world closer, but with an increasing awareness of differences, particularly across the given historical and eco‐political divides. The challenge to research is to communicate meaningfully across these divides. This article explores the issues surrounding cross‐cultural interviewing. Against the backdrop of growing emphasis on cross‐cultural research, there is an emerging need to reconsider interviewing as a research tool with a focus on the interview participants' subjectivities and the subsequent interplay with data collection and making meaning. This entails a recognition of the deep consequences of culture — the embedded patterns of behaviour and the processes of making meaning — and the significance of how these impact on doing research across cultures.
What kind of creature is a design experiment?
Authors: Gorard Stephen , Roberts Karen , Taylor Chris
Published: August 2004

This article considers the emerging method of design experimentation, and its developing use in educational research. It considers the extent to which design experiments are different from other, more established, methods and the extent to which elements of established methods can be adapted for use in conjunction with them. One major issue to be addressed before the metaphors and methods of design experiments can be fully accepted is that they assume the combination of different forms of data from different sources. How this combination takes place is, as yet, unresolved. The article, therefore, looks at similar problems also faced in ‘new’ political arithmetic, research syntheses and field trials to see how lessons learned in these approaches could help in the development of the design field.
The new imperialism & Africa in the global electronic village
Authors: Ya'u Y.Z.
Published: August 2004

Globalisation is enabled by new information and communication technologies (ICTs) that have made it easy to move vast quantities of market information and intelligence, as well as capital, around the world. Conscious of the importance of ICTs in the globalisation process, the World Trade Organization (WTO) has developed a vision for structuring the ICT sector in developing countries. However, although embedded in international efforts to address the digital divide, itself occasioned by uneven access to ICTs at a range of geographic scales, WTO strategy for configuring the ICT sectors of developing countries appears to work in the interest of multinational corporations. Furthermore, WTO policy initiatives, especially those which come under the ambit of the Agreement on Telecommunications, GATs and TRIPs, have tended to exacerbate the digital divide. The result is the resurgence of imperialism, this time represented by knowledge dependence. While locating the marginality of Africa in cyberspace within its colonial past, this paper argues that current international attempts at bridging the digital divide are part of wider efforts to not only secure the virgin markets of developing countries, but also to configure the world in the interest of the new imperial powers. Within this context, therefore, Africa faces the challenge of imperialism anew. The paper discusses the substance of this challenge, and argues that while isolationism cannot be promoted as a counter-force to globalisation, Africa must re-establish the basis of its integration into a globalising world by developing a framework that challenges the dominant assumptions of processes of globalisation promoted by the WTO.
Culture & historical knowledge in Africa: A Cabralian approach
Authors: Ishemo Shubi L.
Published: August 2004

This article will seek to examine the current debates about what some have characterised as an information age, a network society in the context of capitalist globalisation and its socio-cultural and political implications. It will seek to problematise the problem historically and to argue for the continued relevance of the role of history and culture in the shaping of African approaches to the so-called information revolution. It will argue that the dominant perspective on the significance of the communication and information technologies in the African socio-economic, political and cultural processes have been based on the resuscitated modernisation theories and a resurgent neo-liberal ideology which seeks to legitimize the capitalist counter-revolution on a world scale. The re-colonisation of Africa and much of the countries of the South has been accompanied by a crisis whose profoundly devastating effects on humanity are very well known. Debates as to resolve the worldwide crisis have included the role that communication and information technologies might play. It will be suggested that this has resulted in problems that are synonymous to those which Amilcar Cabral and others sought to confront and shape the intellectual tools that guided the national liberation struggle. In the current historical epoch, those intellectual tools are relevant in the struggle for the re-humanisation of humanity. They will be characterised by what Fidel Castro has termed the ‘battle of ideas’. It will be suggested that this will be best waged through the recovery of the positive cultural and historical knowledge of the African people and the selective borrowing and re-adaptation of positive cultural and intellectual tools from other societies. That will result in the liberation of the processes of the development of the productive forces. A liberatory use of information and communication technologies has to be concretized in the socio-cultural realities of Africa.
Effect of influenza vaccinations on immune response and serum eotaxin level in patients with allergic bronchial asthma
Authors: Jahnz-Różyk Karina , Brydak Lidia B. , Targowski Tomasz , Machała Magdalena , Płusa Tadeusz
Published: August 2004

BACKGROUND: One of the most promising markers of allergic inflammation is eotaxin, which has a selective influence on the migration of eosinophils. Its serum content significantly correlates with the intensity of allergic symptoms, so it might be interesting to know whether vaccination has any influence on serum expression of this chemokine.

Aims: Comparison of the humoral response to influenza vaccine and post‐vaccination changes in the serum eotaxin level in patients with allergic bronchial asthma and healthy controls.

Methods: Forty‐two asthmatics and 45 healthy individuals were vaccinated with a single dose of influenza subunit vaccine (Influvac). The serum eotaxin level and the antibody response to haemagglutinin (HI) and neuraminidase (NI) glycoproteins were measured before and after vaccination.

Results: A significant increase of geometric mean titres of HI and NI was observed in both groups. There were no significant differences between the groups in meanfold increase of HI and NI titres, response rate and protective level of HI. After vaccination, a significant decrease of the mean serum eotaxin value was observed in patients with asthma (149.4±71.0 versus 125.1±67.0, p = 0.0017), while no similar effect was present in healthy individuals (153.4±56.9 versus 159.3±54.4, p = 0.5).

Conclusions: The results indicate that in patients with allergic bronchial asthma influenza vaccinations assure efficient protective antibody level and modulate the serum level of eotaxin.
Production of anti‐Candida antibodies in mice with gut colonization of Candida albicans
Authors: Tansho Shigeru , Abe Shigeru , Ishibashi Hiroko , Mitsuya Masayasu , Wada Kayoko , Ikeda Tatsuo , Suegara Nobuo , Koshio Osamu , Ono Yasuo , Yamaguchi Hideyo
Published: August 2004

BACKGROUND: Production of antibodies that are specific for allergens is an important pathological process in inflammatory allergic diseases. These contain the antibodies against antigens of Candida albicans, one of the normal microbial flora in an intestinal tract. We studied the effects of the prednisolone administration on the production of anti‐Candida antibodies in the gastrointestinally C. albicans‐colonized mice.

Methods and Materials: BALB/c mice, treated with antibacterial antibiotics to decontaminate indigenous intestinal bacterial flora, were inoculated intragastrically with C. albicans. The mice, in which C. albicans grows intestinally, were administered prednisolone to induce temporary immunosuppression. The Candida growth in their intestinal tract and their antibody response to Candida were examined.

Results: Antibiotic treatment allowed establishment of C. albicans gastrointestinal colonization, but did not cause subsequent systemic dissemination of C. albicans in all the animals. When these animals received an additional treatment with prednisolone, they showed a significantly higher population of C. albicans in their feces than those of animals treated with antibiotics alone, and the organisms were recovered even from their kidney. This systemic dissemination by C. albicans appeared to be temporal, because all the mice survived without any symptoms for more than 2 months. Examination of the serum titers of total immunoglobulin (Ig)E antibodies and specific IgE and IgG antibodies against Candida antigens demonstrated that titers of total IgE increased, partially by day 14 and clearly at day 27, in prednisolone‐treated Candida‐colonized mice. Without prednisolone treatment, an increment of the serum titer was scarcely observed. By day 27, corresponding to the increase of total IgE, the anti‐Candida IgE and IgG titer increased in mice of the prednisolone‐treated group.

Conclusion: Administration of prednisolone to Candida‐colonized mice can induce production of the IgG, IgE antibodies against Candida antigens, perhaps through temporal systemic dissemination of Candida from the intestinal tract.
Trypanosoma cruzi and its components as exogenous mediators of inflammation recognized through Toll‐like receptors
Authors: Campos Marco A. , Gazzinelli Ricardo T.
Published: August 2004

TRYPANOSOMA cruzi is the etiologic agent of Chagas′ disease, a parasitic disease of enormous importance in Latin America. Herein we review the studies that revealed the receptors from innate immunity that are involved in the recognition of this protozoan parasite. We showed that the recognition of T. cruzi and its components occurs through Toll‐like receptors (TLR) 2/CD14. Further, we showed in vivo the importance of the myeloid differentiation factor (MyD88), an adapter protein essential for the function of TLRs, in determining the parasitemia and mortality rate of mice infected with T. cruzi. We also discuss the implications of these findings in the pathophysiology of Chagas′ disease.
Gene clustering by Latent Semantic Indexing of MEDLINE abstracts
Authors: Homayouni Ramin , Heinrich Kevin , Wei Lai , Berry Michael W.
Published: August 2004

Motivation: A major challenge in the interpretation of high-throughput genomic data is understanding the functional associations between genes. Previously, several approaches have been described to extract gene relationships from various biological databases using term-matching methods. However, more flexible automated methods are needed to identify functional relationships (both explicit and implicit) between genes from the biomedical literature. In this study, we explored the utility of Latent Semantic Indexing (LSI), a vector space model for information retrieval, to automatically identify conceptual gene relationships from titles and abstracts in MEDLINE citations.

Results: We found that LSI identified gene-to-gene and keyword-to-gene relationships with high average precision. In addition, LSI identified implicit gene relationships based on word usage patterns in the gene abstract documents. Finally, we demonstrate here that pairwise distances derived from the vector angles of gene abstract documents can be effectively used to functionally group genes by hierarchical clustering. Our results provide proof-of-principle that LSI is a robust automated method to elucidate both known (explicit) and unknown (implicit) gene relationships from the biomedical literature. These features make LSI particularly useful for the analysis of novel associations discovered in genomic experiments.

Availability: The 50-gene document collection used in this study can be interactively queried at http://shad.cs.utk.edu/sgo/sgo.html

Contact:  rhomayouni@utmem.edu

Supplementary information:  http://shad.cs.utk.edu/sgo/pubs.html
Outcome signature genes in breast cancer: is there a unique set?
Authors: Ein-Dor Liat , Kela Itai , Getz Gad , Givol David , Domany Eytan
Published: August 2004

Motivation: Predicting the metastatic potential of primary malignant tissues has direct bearing on the choice of therapy. Several microarray studies yielded gene sets whose expression profiles successfully predicted survival. Nevertheless, the overlap between these gene sets is almost zero. Such small overlaps were observed also in other complex diseases, and the variables that could account for the differences had evoked a wide interest. One of the main open questions in this context is whether the disparity can be attributed only to trivial reasons such as different technologies, different patients and different types of analyses.

Results: To answer this question, we concentrated on a single breast cancer dataset, and analyzed it by a single method, the one which was used by van't Veer et al. to produce a set of outcome-predictive genes. We showed that, in fact, the resulting set of genes is not unique; it is strongly influenced by the subset of patients used for gene selection. Many equally predictive lists could have been produced from the same analysis. Three main properties of the data explain this sensitivity: (1) many genes are correlated with survival; (2) the differences between these correlations are small; (3) the correlations fluctuate strongly when measured over different subsets of patients. A possible biological explanation for these properties is discussed.

Contact:  eytan.domany@weizmann.ac.il

Supplementary information:  http://www.weizmann.ac.il/physics/complex/compphys/downloads/liate/
A rapid method for computationally inferring transcriptome coverage and microarray sensitivity
Authors: Reverter A. , McWilliam S. M. , Barris W. , Dalrymple B. P.
Published: August 2004

Motivation: There are many different gene expression technologies, including cDNA and oligo-based microarrays, SAGE and MPSS. For each organism of interest, coverage of the transcriptome and the genome will be different. We address the question of what level of coverage is required to exploit the sensitivity of the different technologies, and what is the sensitivity of the different approaches in the experimental study.

Results: We estimate the transcriptome coverage by randomly sampling transcripts from a pre-defined tag-to-gene mapping function. For a given microarray experiment, we locate the thresholds in intensities that define the distribution of transcript abundance. These values are compared against the distribution obtained by applying the same thresholds to the intensities from differentially expressed genes. The ratio of these two distributions meets at the equilibrium defining sensitivity. We conclude that a collection of ∼340 000 sequences is adequate for microarrays, but not large enough for maximum utilization of tag-based technologies. In the absence of large-scale sequencing, the majority of the tags detected by the latter approaches will remain unidentified until the genome sequence is available.

Contact:  Tony.Reverter-Gomez@csiro.au
Origins of introns based on the definition of exon modules and their conserved interfaces
Authors: de Roos Albert D. G.
Published: August 2004

Summary: Central to the unraveling of the early evolution of the genome is the origin and role of introns. The evolution of the genome can be characterized by a continuous expansion of functional modules that occurs without the interruption of existing processes. The design-by-contract methodology of software development offers a modular approach to design that seeks to increase flexibility by focusing on the design of constant interfaces between functional modules. Here, it is shown that design-by-contract can offer a framework for genome evolution. The definition of an ancient exon module with identical splice sites leads to a relatively simple sequence of events that explains the role of introns, intron phase differences and the evolution of multi-exon proteins in an RNA world. An interaction of the experimentally defined six-nucleotide splicing consensus sequence together with a limited number of primitive ribozymes can account for a rapid creation of protein diversity.

Contact:  albert.de.roos@thebeaglearmada.nl
Mycobacterium parmense sp. nov.
Authors: Fanti Franco , Tortoli Enrico , Hall Leslie , Roberts Glenn D. , Kroppenstedt Reiner M. , Dodi Icilio , Conti Stefania , Polonelli Luciano , Chezzi Carlo
Published: August 2004

The isolation and identification of a novel, slow-growing, scotochromogenic, mycobacterial species is reported. A strain, designated MUP 1182T, was isolated from a cervical lymph node of a 3-year-old child. MUP 1182T is alcohol- and acid-fast, with a lipid pattern that is consistent with those of species that belong to the genus Mycobacterium. It grows slowly at 25–37 °C, but does not grow at 42 °C. The isolate was revealed to be biochemically distinct from previously described mycobacterial species: it has urease and Tween hydrolysis activities and lacks nitrate reductase, 3-day arylsulfatase and β-glucosidase activities. Comparative 16S rDNA sequencing showed that isolate MUP 1182T represents a novel, slow-growing species that is related closely to Mycobacterium lentiflavum and Mycobacterium simiae. On the basis of these findings, the name Mycobacterium parmense sp. nov. is proposed, with MUP 1182T (=CIP 107385T=DSM 44553T) as the type strain.