bluuebunny/crossref_metadata_2025 huggingface dataset:
French second language acquisition research: setting the scene
Authors: MYLES FLORENCE
Published: January 2005

This introductory article introduces the field of second language acquisition (SLA) to specialists in French linguistics who are not familiar with it. Its purpose is to present a map of the field which will then enable the reader to better situate the following in depth articles which present focused theoretical and empirical investigations as they apply to French. The first part summarises recent, and sometimes apparently contradictory, research findings. The second part explores the theoretical approaches which have been most influential in recent investigations, outlining where each of these approaches originates, and which aspects of the SLA process it investigates.
The contribution of the theory of Universal Grammar to our understanding of the acquisition of French as a second language
Authors: HAWKINS ROGER
Published: January 2005

Human beings have a genetically-determined capacity to walk, rather than to fly or swim. People can learn to swim, but it is not something that is genetically programmed. Do humans have a genetically-determined capacity to acquire language? Universal Grammar is a theory that assumes that they do. Except in cases of genetic disorder, humans have specialised mental architecture which is uniform across the species in its initial state, and which determines the ways in which samples of language encountered are converted into mental grammars. The specialised architecture is Universal Grammar, and it underlies our capacity to acquire particular languages like English, French, Chinese and so on. Two questions that need to be asked immediately about Universal Grammar if it is to be of any interest in understanding the acquisition of French as a second language are: (i) What evidence is there that Universal Grammar is operating when people who have already acquired a native language learn French as a second language? (ii) What insight does the adoption of a theory of Universal Grammar bring to understanding the processes involved, the course of development over time and the nature of the end state grammars that learners achieve? The article presents empirical evidence from a selection of studies bearing on these questions. It will be argued that the assumption that humans have mental architecture dedicated specifically to language acquisition – Universal Grammar – even in the case of second language acquisition, has allowed considerable progress to be made in understanding second language French.
Itinéraires acquisitionnels et stades de développement en français L2
Authors: BARTNING INGE , SCHLYTER SUZANNE
Published: January 2005

Nous proposons ici des stades de développement du français acquis par les adultes suédophones, formulés comme profils grammaticaux d'apprenants à des niveaux différents. Cette proposition se fonde sur les résultats empiriques des travaux menés au sein de deux projets différents sur l'acquisition du français L2 des apprenants suédophones. À partir d'itinéraires acquisitionnels nous proposons six stades, qui s'étendent des débuts de l'acquisition jusqu'à la production d'apprenants quasi-natifs. Ces itinéraires, et les stades que nous essayons d'en déduire, reflètent l'acquisition du français de l'apprenant suédophone, dans des situations orales spontanées où elle/il doit avoir recours à ses connaissances automatiques. Le cadre de cette étude est donc descriptif et empirique. Un objectif ultérieur est de servir de base à une évaluation du niveau grammatical d'un certain apprenant à un moment donné.
The acquisition of sociolinguistic competence in French as a foreign language: an overview
Authors: DEWAELE JEAN-MARC
Published: January 2005

The present contribution presents an overview of studies in French as a second (L2) and/or foreign language that consider the effects of extralinguistic variables (mostly instructional, experiential and situational factors) on the development of sociolinguistic competence. It focuses specifically on variation between informal and formal variants in phonology, morphology, morpho-syntax and the lexicon.
Research on form-focused instruction in immersion classrooms: implications for theory and practice
Authors: LYSTER ROY
Published: January 2005

This article presents a comparative analysis of five quasi-experimental studies involving close to 1,200 students, ranging in age from 7 to 14, in 49 French immersion classrooms in Canada – a content-based instructional context where learners develop high levels of communicative ability yet demonstrate a levelling-off effect in their grammatical development. The studies investigated the effects of form-focused instruction on four areas known to be difficult for anglophone learners of French: perfect vs. imperfect past tense, conditional mood, second-person pronouns and grammatical gender. Findings suggest that effective form-focused instruction in immersion contexts, at least with respect to interlanguage features that have reached a developmental plateau, includes a balanced distribution of opportunities for noticing, language awareness and controlled practice with feedback. Less effective instructional options overemphasise negotiation for meaning in oral tasks where message comprehensibility and communication strategies circumvent the need for learners to move beyond the use of interlanguage forms.
French interlanguage oral corpora: recent developments
Authors: RULE SARAH
Published: January 2005

The raw data for any second language acquisition research, namely interlanguage corpora, are one of our most expensive resources to collect. New methodologies now make it relatively easy to share this resource, by storing digitised soundfiles and transcripts on the Internet, thus making oral interlanguage corpora accessible to other L2 researchers.

The article first discusses the possibilities offered by new methodologies, in terms of data storage, management and data analysis, and it then presents current efforts to develop web-based access to French oral interlanguage corpora of learners at different levels and with different backgrounds.

Finally, the article presents a short inventory of the French interlanguage oral corpora currently available, indicating in each case the author and main outputs to date, as well as providing information about the learners, the format of the corpus (e.g. longitudinal versus cross-sectional data; transcription conventions) and its accessibility to users.
Research into the second language acquisition of French: achievements and challenges
Authors: TOWELL RICHARD
Published: January 2005

This final article re-examines the approaches outlined in the other articles in this Special Issue in order to evaluate the contribution which each one has brought to the study of the second language acquisition of French. The final section identifies the difficulty for all approaches of stating how input can be converted into intake and suggests three possible ways forward.
Special Issue on: The acquisition of French as a second language
Authors: MYLES FLORENCE , TOWELL RICHARD
Published: January 2005

This is the first Special Issue of the Journal of French Language Studies, which will from now on have one thematic number per year. This issue is devoted to the acquisition of French as a second language.
Race, space and the regulation of prostitution in Colonial Hong Kong
Authors: HOWELL PHILIP
Published: January 2005

The geography of the regulation of sex work in colonial Hong Kong is examined as a contribution to the historiography of the colonial city. Particular attention is paid to racial and sexual segregation and their relation to Foucauldian concepts of discipline and regulated sexuality. The introduction and revision of Venereal Disease Ordinances, and the landscape of regulated prostitution that resulted, are read as part of a mid-nineteenth-century crisis of government. Ultimately, the political and discursive construction of Chinese racial/cultural difference reveals the limits of ‘imperial governmentality’ as much as the ambition of colonial sexual discipline.
‘An infection of locality’: plague, pythogenesis and the poor in Bombay, c. 1896–1905
Authors: KIDAMBI PRASHANT
Published: January 2005

In September 1896, a virulent plague epidemic broke out in the colonial port city of Bombay. Central to existing interpretations of the epidemic has been the pervasive assumption that colonial policies aimed at suppressing the disease were principally informed by ‘contagionist’ etiological doctrine. However, this article argues that long-standing ‘localist’ etiological theories continued to exercise a critical influence over colonial policies. It thereby highlights the explicit ‘class’ bias that informed the colonial state's anti-plague offensive, which was largely directed at the urban poor.
Initial stage in lightning initiated from tall objects and in rocket‐triggered lightning
Authors: Miki M. , Rakov V. A. , Shindo T. , Diendorfer G. , Mair M. , Heidler F. , Zischank W. , Uman M. A. , Thottappillil R. , Wang D.
Published: January 2005

We examine the characteristics of the initial stage (IS) in object‐initiated lightning derived from current measurements on the Gaisberg tower (100 m, Austria), the Peissenberg tower (160 m, Germany), and the Fukui chimney (200 m, Japan) and their counterparts in rocket‐triggered lightning in Florida. All lightning events analyzed here effectively transported negative charge to ground. For rocket‐triggered lightning the geometric mean (GM) values of the three overall characteristics of the initial stage, duration, charge transfer, and average current, are similar to their counterparts for the Gaisberg tower flashes and the Peissenberg tower flashes, while the Fukui chimney flashes are characterized by a shorter GM IS duration and a larger average current. The GM IS charge transfer for the Fukui chimney flashes is similar to that in the other three data sets. The GM values of the action integral differ considerably among the four data sets, with the Fukui action integral being the largest. The observed differences in the IS duration between the Fukui data set and all other data considered here are probably related to the differences in the lower current limits, while the differences in the action integral cannot be explained by the instrumental effects only. There appear to be two types of initial stage in upward lightning. The first type exhibits pulsations (ringing) during the initial portion of the IS, and the second type does not. The occurrence of these types of IS appears to depend on geographical location. The characteristics of pulses superimposed on the initial continuous current (ICC pulses) in object‐initiated (Gaisberg, Peissenberg, and Fukui) lightning are similar within a factor of 2 but differ more significantly from their counterparts in rocket‐triggered lightning. Specifically, the ICC pulses in object‐initiated lightning exhibit larger peaks, shorter risetimes, and shorter half‐peak widths than do the ICC pulses in rocket‐triggered lightning.
Direct N2O emissions from rice paddy fields: Summary of available data
Authors: Akiyama Hiroko , Yagi Kazuyuki , Yan Xiaoyuan
Published: January 2005

Rice cultivation is an important anthropogenic source of atmospheric nitrous oxide (N2O) and methane. We compiled and analyzed data on N2O emissions from rice fields (113 measurements from 17 sites) reported in peer‐reviewed journals. Mean N2O emission ± standard deviation and mean fertilizer‐induced emission factor during the rice‐cropping season were, respectively, 341 ± 474 g N ha−1 season−1 and 0.22 ± 0.24% for fertilized fields continuously flooded, 993 ± 1075 g N ha−1 season−1 and 0.37 ± 0.35% for fertilized fields with midseason drainage, and 667 ± 885 g N ha−1 season−1 and 0.31 ± 0.31% for all water regimes. The estimated whole‐year background emission was 1820 g N ha−1 yr−1. A large uncertainty remains, especially for background emission because of limited data availability. Although midseason drainage generally reduces CH4 and increases N2O emissions, it may be an effective option for mitigating the net global warming potential of rice fields.
Global assimilation of satellite surface soil moisture retrievals into the NASA Catchment land surface model
Authors: Reichle Rolf H. , Koster Randal D.
Published: January 2005

Global retrievals of surface soil moisture from the Scanning Multichannel Microwave Radiometer for the period 1979–87 are assimilated into the NASA Catchment land surface model as it is driven with surface meteorological data derived from observations. Validation against ground‐based measurements in Eurasia and North America from the Global Soil Moisture Data Bank demonstrates a long assumed (but rarely proven) property of soil moisture fields derived from data assimilation – that the assimilation product is superior to either satellite data or model data alone. An analysis of the innovations reveals that the filter is only partially operating within its underlying assumptions and offers clues how spatially distributed model error parameters could further enhance filter performance.
Ion aurora and its seasonal variations
Authors: Newell P. T. , Wing S. , Sotirelis T. , Meng C.‐I.
Published: January 2005

Recent studies have shown that intense discrete aurora, auroral kilometric radiation, upflowing ion beams, and downward directed electric fields are more intense in the winter hemisphere than in the summer. This is particularly true of the dusk to midnight sector where intense electron aurora are most common. Here we use one solar cycle of DMSP satellite particle data to investigate the seasonality of the ion aurora. The ion aurora proves to be approximately equal in the summer and winter hemispheres in the dusk‐midnight sector (with the summer hemisphere favored by 0 to 4%). However, in the MLT hours from midnight to dawn, the ion precipitating energy flux is 15–40% higher in winter than in summer. The absolute magnitude of the ion effect is smaller than was found for discrete electron aurora (which show a threefold difference between winter and summer). The seasonal behavior of the ions may reflect the observation that diverging electric fields, which accelerate ions downward, are found mainly postmidnight, and are stronger in the winter. The relative weakness of the seasonal effects in ions may reflect their high average energy (many tens of keV), which is substantially larger than typical of electric potentials found in the auroral circuit. Ions in the dusk to midnight sector are most intense equatorward of the region of discrete aurora, and are thus probably not much affected by the seasonality of the field‐aligned electric fields which exist there (and which are of the sense to retard ion precipitation). Interestingly, ion average energies are higher in the winter hemisphere than in the summer hemisphere at all local times, regardless of whether or not energy fluxes are enhanced. The above results apply to the actual range of ion energies measured by the DMSP electrostatic analyzers (32 eV to 30 keV). A sample extrapolation to 100 keV energy, assuming the spectra are Maxwellian, showed the same overall pattern. The percentage by which the winter hemisphere was favored over the summer for precipitating ion energy flux was moderately larger when using extrapolation, and a larger difference was still seen postmidnight than premidnight.
Numerical simulation of hydrothermal vent‐induced circulation at Endeavour Ridge
Authors: Thomson Richard E. , Subbotina Marina M. , Anisimov Mikhail V.
Published: January 2005

Hydrothermal venting at Endeavour Ridge is focused at five major vent fields spaced at ∼2‐km intervals along a narrow (∼1 km wide) north‐south trending rift‐valley. A Princeton Ocean Model with an axially symmetric rift‐valley centered within a rotating, full‐depth (2400 m) stratified ocean is used to simulate the circulation and associated temperature and salinity fields generated by vertical heat fluxes from the five vent fields. Steady seafloor heat fluxes are introduced instantaneously to a quiescent ocean using the model provision for boundary fluxes. The model achieves a quasi‐steady state in about 80 days. Results are consistent with observation. In particular, buoyant plumes emanating from the larger vent fields rise to “trapping” depths as shallow as 1850 m (∼350 m above bottom) and spread laterally with the vent‐induced circulation. Plume anomalies remain confined to within several kilometers of the ridge, except to the west where anomalies extend more than 10 km off‐axis. As with observations, modeled currents within the valley consist of a strong (∼10 cm s−1) poleward inflow within roughly 75 m of the bottom and an equally strong equatorward counterflow above that depth. Weak (∼1 cm s−1) equatorward flow develops over the flank of the west ridge and weak poleward flow over the flank of the east ridge. Cyclonic relative vorticity dominates the model circulation within the valley while anticyclonic vorticity prevails above the depth of neutral plume buoyancy. Findings support the notion that turbulent entrainment by buoyant plumes forces a mean poleward flow within the confines of the Endeavour Ridge axial valley.
Changes in the vertical distribution of ozone over Canada from ozonesondes: 1980–2001
Authors: Tarasick D. W. , Fioletov V. E. , Wardle D. I. , Kerr J. B. , Davies J.
Published: January 2005

Measurements of the vertical profile of ozone concentration using balloon‐borne ECC ozonesondes have been made weekly since 1980 at several sites in Canada (Edmonton, Goose Bay, Churchill, and Resolute), since 1987 at Alert, and since 1992 at Eureka. Previous analyses of ozone trends over Canada have shown strong negative trends in tropospheric ozone. We present here a new analysis of trends in the vertical distribution of ozone with data up to the end of 2001. In addition, more detailed attention is paid to some potential sources of bias: total ozone correction, background current correction, and time‐of‐launch (diurnal) variation. For the 1980–2001 period the overall linear trends are primarily negative, both in tropospheric and stratospheric ozone. However, when the data for 1991–2001 only are considered, the trends are positive, even in the lower stratosphere. When the time series are compared with previously reported trends (to 1993), it is evident that ozone has rebounded at all levels below about 63 hPa. These differences do not appear to be related to changes in tropopause height, as the average height of the tropopause (as measured over the ozonesonde stations) has not changed over either the 22‐year or the 11‐year period. Nevertheless, comparison with another dynamical indicator, the wintertime frequency of occurrence of laminae in the ozone profile, suggests that this rebound may be partly a result of small changes in the atmospheric circulation, rather than a recovery of the ozone layer from halocarbon‐induced depletion. The long‐term trends in average tropospheric ozone concentrations over Canada are similar to corresponding lower stratospheric trends, and tropospheric ozone levels show significant correlation with lower stratospheric ozone amounts.
UV radiation in the Netherlands: Assessing long‐term variability and trends in relation to ozone and clouds
Authors: den Outer P. N. , Slaper H. , Tax R. B.
Published: January 2005

The variability and long‐term changes in the ultraviolet (UV) climate in the Netherlands have been studied in relation to ozone and clouds, by analyzing modeled and measured values for daily, monthly, and yearly integrated erythemally weighted UV doses. At Bilthoven, Netherlands (longitude 5.19°E, latitude 52.12°N), UV irradiance measurements for the 1994–2003 period yielded a mean annual dose of 447 ± 29 kJ/m2 and a mean daily dose of 2.5 ± 0.5 kJ/m2 for June and July. On average, the maximum UV index exceeded 6.5 (i.e., 0.1625 W/m2 erythemally weighted) on 10 days per year (21 days in 2003). The mean value of measured‐to‐modeled ratios of erythemal UV irradiances was 1.00 with a standard deviation of 0.06 for days when the measured global solar radiation agrees within 5% with the cloudless sky value. Three previously introduced approaches to model cloud effects on UV doses were shown to have limitations when applied for low Sun and/or optically thick clouds, while a new approach provided the most consistent results with an average ratio of the measured‐to‐modeled daily doses of 1.02 and a standard deviation of 0.09, for all seasons and weather conditions for the period 1994–2002. Further analysis also revealed a wavelength dependency of the correlation between global solar radiation and UV radiation. Clouds, on average, reduced the daily dose of erythemal UV to 68% of the clear‐sky value, whereas for global solar radiation this was 57%. The modeled annual erythemal UV dose was 622 kJ/m2 (402 kJ/m2) averaged over the years 1979–1982, while the years 2000–2003 yield 662 kJ/m2 (448 kJ/m2) for cloudless (cloudy) conditions. In the past 25 years the highest annual doses were received in 1995 (485 kJ/m2) and 2003 (488 kJ/m2): in 1995 as a result of extremely low ozone values and moderate cloud reduction and in 2003 as a result of extremely low cloud reduction combined with moderately low ozone values. As an indication of the changes over time, a linear regression is performed showing that the annual UV dose received at the ground for all weather conditions increased with 5.5 ± 2% per decade for erythemal UV over the 1979–2003 period.
Simulation of climate response to aerosol direct and indirect effects with aerosol transport‐radiation model
Authors: Takemura Toshihiko , Nozawa Toru , Emori Seita , Nakajima Takashi Y. , Nakajima Teruyuki
Published: January 2005

With a global aerosol transport‐radiation model coupled to a general circulation model, changes in the meteorological parameters of clouds, precipitation, and temperature caused by the direct and indirect effects of aerosols are simulated, and its radiative forcing are calculated. A microphysical parameterization diagnosing the cloud droplet number concentration based on the Köhler theory is introduced into the model, which depends not only on the aerosol particle number concentration but also on the updraft velocity, size distributions, and chemical properties of each aerosol species and saturation condition of the water vapor. The simulated cloud droplet effective radius, cloud radiative forcing, and precipitation rate, which relate to the aerosol indirect effect, are in reasonable agreement with satellite observations. The model results indicate that a decrease in the cloud droplet effective radius by anthropogenic aerosols occurs globally, while changes in the cloud water and precipitation are strongly affected by a variation of the dynamical hydrological cycle with a temperature change by the aerosol direct and first indirect effects rather than the second indirect effect itself. However, the cloud water can increase and the precipitation can simultaneously decrease in regions where a large amount of anthropogenic aerosols and cloud water exist, which is a strong signal of the second indirect effect. The global mean radiative forcings of the direct and indirect effects at the tropopause by anthropogenic aerosols are calculated to be −0.1 and −0.9 W m−2, respectively. It is suggested that aerosol particles approximately reduce 40% of the increase in the surface air temperature by anthropogenic greenhouse gases on the global mean.
Critical shear stress for erosion of cohesive soils subjected to temperatures typical of wildfires
Authors: Moody John A. , Smith J. Dungan , Ragan B. W.
Published: January 2005

Increased erosion is a well‐known response after wildfire. To predict and to model erosion on a landscape scale requires knowledge of the critical shear stress for the initiation of motion of soil particles. As this soil property is temperature‐dependent, a quantitative relation between critical shear stress and the temperatures to which the soils have been subjected during a wildfire is required. In this study the critical shear stress was measured in a recirculating flume using samples of forest soil exposed to different temperatures (40°–550°C) for 1 hour. Results were obtained for four replicates of soils derived from three different types of parent material (granitic bedrock, sandstone, and volcanic tuffs). In general, the relation between critical shear stress and temperature can be separated into three different temperature ranges (<175°C; 175°C–275°C; >275°C), which are similar to those for water repellency and temperature. The critical shear stress was most variable (1.0–2.0 N m−2) for temperatures <175°C, was a maximum (>2.0 N m−2) between 175° and 275°C, and was essentially constant (0.5–0.8 N m−2) for temperatures >275°C. The changes in critical shear stress with temperature were found to be essentially independent of soil type and suggest that erosion processes in burned watersheds can be modeled more simply than erosion processes in unburned watersheds. Wildfire reduces the spatial variability of soil erodibility associated with unburned watersheds by eliminating the complex effects of vegetation in protecting soils and by reducing the range of cohesion associated with different types of unburned soils. Our results indicate that modeling the erosional response after a wildfire depends primarily on determining the spatial distribution of the maximum soil temperatures that were reached during the wildfire.
Propagation model for transionospheric fluctuating paths of propagation: Simulator of the transionospheric channel
Authors: Gherm Vadim E. , Zernov Nikolay N. , Strangeways Hal J.
Published: January 2005

A new model for scintillation on transionospheric links, based on a hybrid method and valid for strong scintillations, has been developed and used to construct a software transionospheric channel simulator. The method is a combination of the complex phase method and the random screen technique. The parameters of the random screen are determined as the result of a rigorous solution to the problem of propagation inside the ionosphere using the extended Rytov approximation (the complex phase method). The random two‐dimensional spatial spectrum at the screen is then transferred down to the Earth's surface employing the rigorous relationships of the random screen theory. Thus the complex phase method can adequately introduce a random screen below the ionosphere for L‐band frequencies. The technique is capable of producing statistical characteristics and simulating time realizations of the field for a wide range of input parameters. Preliminary results are presented for both weak and strong scintillations.
Structural and kinematic relationships between Corsica and the Pyrenees‐Provence domain at the time of the Pyrenean orogeny
Authors: Lacombe Olivier , Jolivet Laurent
Published: January 2005

The Pyrenees‐Provence belt and the Alps were both active in the late Eocene. Alpine Corsica was once a part of the Alps, and the now obducted metamorphic oceanic domain is similar and easily correlated in both areas. Tectonic reconstructions before the Oligo‐Miocene opening of the Liguro‐Provençal basin show that at the same time, Corsica was located in the hinterland of the Provençal ranges. A late Eocene cross section running from Alpine Corsica to Provence gives an image of a complete mountain belt from an internal domain made of metamorphosed oceanic material (Alpine Corsica) to the foreland fold and thrust with a thin‐skinned geometry (Provence). During the late Eocene the intervening basement of western Corsica was thus within this mountain belt, probably thrust onto the European basement. We analyze and interpret the structural pattern and the overall geometry of the Provençal‐Corsican domain during late Eocene times in terms of oblique convergence and strain partitioning, within the framework of the Africa‐Eurasia convergence. This evolution is integrated in a set of kinematic reconstructions of the western Mediterranean region from 65 Ma to the present.
Macrophytes as indicators of land‐derived wastewater: Application of a δ15N method in aquatic systems
Authors: Cole Marci L. , Kroeger Kevin D. , McClelland James W. , Valiela Ivan
Published: January 2005

We measured δ15N signatures of macrophytes and particulate organic matter (POM) in six estuaries and three freshwater ponds of Massachusetts to assess whether the signatures could be used as indicators of the magnitude of land‐derived nitrogen loads, concentration of dissolved inorganic nitrogen in the water column, and percentage of N loads contributed by wastewater disposal. The study focused specifically on sites on Cape Cod and Nantucket Island, in the northeastern United States. There was no evidence of seasonal changes in δ15N values of macrophytes or POM. The δ15N values of macrophytes and POM increased as water column dissolved inorganic nitrogen concentrations increased. We found that δ15N of macrophytes, but not of POM, increased as N load increased. The δ15N values of macrophytes and groundwater NO3 tracked the percent of wastewater contribution linearly. This research confirms that δ15N values of macrophytes and NO3 can be excellent indicators of anthropogenic N in aquatic systems.
Virus factories: associations of cell organelles for viral replication and morphogenesis
Authors: Novoa Reyes R. , Calderita Gloria , Arranz Rocío , Fontana Juan , Granzow Harald , Risco Cristina
Published: January 2005

Genome replication and assembly of viruses often takes place in specific intracellular compartments where viral components concentrate, thereby increasing the efficiency of the processes. For a number of viruses the formation of ‘factories’ has been described, which consist of perinuclear or cytoplasmic foci that mostly exclude host proteins and organelles but recruit specific cell organelles, building a unique structure. The formation of the viral factory involves a number of complex interactions and signalling events between viral and cell factors. Mitochondria, cytoplasmic membranes and cytoskeletal components frequently participate in the formation of viral factories, supplying basic and common needs for key steps in the viral replication cycle.
Early and delayed aspects of nuclear reprogramming during cloning
Authors: Latham Keith E.
Published: January 2005

The successful production of viable progeny following adult somatic cell nuclear transfer (cloning) provides exciting new opportunities for basic research for investigating early embryogenesis, for the propagation of valuable or endangered animals, for the production of genetically engineered animals, and possibly for developing therapeutically valuable stem cells. Successful cloning requires efficient reprogramming of gene expression to silence donor cell gene expression and activate an embryonic pattern of gene expression. Recent observations indicate that reprogramming may be initiated by early events that occur soon after nuclear transfer, but then continues as development progresses through cleavage and probably to gastrulation. Because reprogramming is slow and progressive, cloned embryos have dramatically altered characteristics in comparison with fertilized embryos. Events that occur early following nuclear transfer may be essential prerequisites for the later events. Additionally, the later reprogramming events may be inhibited by sub‐optimum culture environments that exist because of the altered characteristics of cloned embryos. By addressing the unique requirements of cloned embryos, the entire process of reprogramming may be accelerated, thus increasing cloning efficiency.
Linkage and linkage disequilibrium analysis of the lipoprotein lipase gene with lipid profiles in Chinese hypertensive families
Authors: YANG Wenjie , HUANG Jianfeng , YAO Cailiang , SU Shaoyong , LIU Donghai , GE Dongliang , GU Dongfeng
Published: January 2005

Elevated TG [triacylglycerol (triglyceride)] is a significant independent risk factor for cardiovascular disease. LPL (lipoprotein lipase) is one of the key enzymes in the metabolism of the TG-rich lipoproteins which hydrolyses TG from the chylomicrons and very-LDL (low-density lipoprotein). To investigate the relationship between the LPL gene and lipid profiles, especially TG, in 148 hypertensive families, we have chosen seven flanking microsatellite markers and four internal markers of the LPL gene and conducted linkage analysis by SOLAR and S.A.G.E. (statistical analysis for genetic epidemiology)/SIBPAL 2 programs, and linkage disequilibrium analysis by QTDT (quantitative transmission/disequilibrium test) and GOLD (graphical overview of linkage disequilibrium). There were statistically significant differences in lipid levels between subjects without and with hypertension within families. A maximum LOD score of 1.3 with TG at the marker D8S261 was observed by SOLAR. Using S.A.G.E./SIBPAL 2, we identified a linkage with TG at the marker ‘ATTT’ located within intron 6 of the LPL gene (P=0.0095). Two SNPs (single nucleotide polymorphisms), HindIII and HinfI, were found in linkage disequilibrium with LDL-cholesterol levels (P=0.0178 and P=0.0088 respectively). A strong linkage disequilibrium was observed between the HindIII in intron 8 and HinfI in the exon 9 (P<0.00001, D′=0.895). Linkage disequilibrium was also found between the ‘ATTT’ polymorphism in intron 6 and two SNPs (P=0.0021 and D′=0.611 for HindIII; and P=0.00004, D′=0.459 for HinfI). The present study in the Chinese families with hypertension suggested that the LPL gene might influence lipid levels, especially TG metabolism. Replication studies both in Chinese and other populations are warranted to confirm these results.
Transcriptomic and proteomic analysis of liver and muscle alterations caused by surgical stress in rats
Authors: LÓPEZ-HELLÍN Joan , GONZALO Ricardo , TEJEDA Mónica , CARRASCAL Montserrat , VILÀ Maya R. , ABIÁN Joaquín , GARCÍA-ARUMÍ Elena
Published: January 2005

The metabolic response to injury includes major alterations in protein metabolism; however, little is known about alterations in the synthesis of individual proteins and their role in the stress response. Our aim was to study how individual proteins in liver and muscle are altered by abdominal surgery. Changes produced in mRNA and proteins by abdominal surgery were studied in rats using RAP (random arbitrary priming)-PCR, to investigate mRNA alterations, and standard or isotopic (with in vivo radioactive labelling of proteins) two-dimensional electrophoresis/MS proteomic analyses, to study differential expression of proteins. Many of the differentially expressed proteins identified in blood were specifically synthesized by the liver to participate in the stress response. The hepatic proteins (antioxidant proteins, serine protease inhibitors, acute-phase proteins and transport proteins) were secreted into the bloodstream to produce a systemic action, indicating the central role of the liver in the stress response. Overexpressed proteins identified in liver were associated with the glycolytic processes and the folding of nascent proteins, confirming the high metabolic activity of the liver after surgery. The role of skeletal muscle protein as an amino acid donor to fuel the processes involved in the stress response was shown by the decrease in high-molecular-mass myofibrillar proteins. Combined use of the three techniques studied, differential RAP-PCR and standard and isotopic proteome analysis, provided complementary information on the differentially expressed proteins in a rat model of surgical stress.
Measurement of critical lower limb tissue hypoxia by coupling chemical and optical techniques
Authors: SALMAN Mahmoud , GLANTZOUNIS Georgios K. , YANG Wenxuan , MYINT Fiona , HAMILTON George , SEIFALIAN Alexander M.
Published: January 2005

It has been a long-term goal to develop non-invasive methods that can detect critical levels of tissue hypoxia to help in the management of chronic lower limb ischaemia. In the present study, skeletal muscle oxygenation was measured using a new Clark-type TCPO2 [transcutaneous PO2 (partial pressure of O2)]/PCO2 (partial pressure of CO2) monitoring system and optical NIRS (near-infrared spectroscopy) at graded levels of hypoxaemia using a rabbit model (n=6). The TCPO2/PCO2 probe was placed on the shaved hindlimb to record SPO2 (skin PO2) and SPCO2 (skin PCO2) continuously. A pair of NIRS probes were placed on the limb to monitor HbO2 (oxyhaemoglobin) and Hb (deoxyhaemoglobin). Graded hypoxaemia was achieved by stepwise reductions of FiO2 (fraction of inspired O2) from 30% to 6%. Animals were allowed to recover after each episode of hypoxia at an FiO2 of 30% as indicated by normalized arterial blood PO2. There was a significant (P<0.05) decrease in SPO2 with all grades of hypoxaemia and no significant changes in SPCO2. There was a significant (P<0.05) increase in muscle Hb with all grades of hypoxaemia and a significant (P<0.05) decrease in HbO2 when FiO2 was below 15%. A significant correlation was found between the SPO2 and HbO2 (r=0.92, P<0.001) and both were significantly correlated with arterial blood PO2 (P<0.001). The new TCPO2/PCO2 system, in addition to its application for the assessment of conditions such as chronic venous insufficiency where alteration in skin oxygenation occurs solely, also has potential in conditions such as peripheral vascular disease where both skin and muscle oxygenation may be affected.
Cross-sectional study of complement C3 as a coronary risk factor among men and women
Authors: ONAT Altan , UZUNLAR Bülent , HERGENÇ Gülay , YAZICI Mehmet , SARI Ibrahim , UYAREL Hüseyin , CAN Günay , SANSOY Vedat
Published: January 2005

In the present study, we examined (i) whether C3 (complement C3) was an independent marker of prevalent CHD (coronary heart disease), and (ii) which preferential associations existed between C3 and some cardiovascular risk factors when jointly analysed with CRP (C-reactive protein) and fibrinogen. In a cohort of 756 unselected adults, 39% of whom had the metabolic syndrome, C3 and other risk variables were evaluated in a cross-sectional manner. In a logistic regression model for the likelihood of CHD, a significant OR (odds ratio) of 3.5 [95% CI (confidence intervals), 1.27 and 9.62)] for C3 was obtained after adjustment for smoking status, TC (total cholesterol) and usage of statins. A similar model, also comprising systolic blood pressure, with a cut-off point of ≥1.6 g/l C3 exhibited a 1.9-fold risk (95% CI, 1.01 and 3.58) compared with individuals below the cut-off point. Both analyses displayed an adjusted OR of 1.37 for each S.D. increment in C3. The significant relationship of C3 with a likelihood of CHD also proved to be independent of CRP. In multiple linear regression models, associations were tested for each acute-phase protein with measures of obesity, fasting insulin, triacylglycerols (triglycerides), TC, HDL (high-density lipoprotein)-cholesterol, physical activity, smoking status, diagnosis of metabolic syndrome and family income. When both genders were combined, C3 was independently associated with serum triacylglycerols, waist circumference, BMI (body mass index) and TC. CRP was independently associated with waist circumference, TC, family income (inversely) and physical activity, and fibrinogen with BMI, TC, smoking status and metabolic syndrome. In summary, elevated levels of complement C3 are associated with an increased likelihood of CHD independent of standard risk factors and regardless of the presence of acute coronary events, suggesting that C3 might be actively involved in coronary atherothrombosis. Unlike CRP and fibrinogen, C3 was preferentially associated with waist girth and serum triacylglycerols.
Cardiac autonomic activity and Type II diabetes mellitus
Authors: MANZELLA Daniela , PAOLISSO Giuseppe
Published: January 2005

CAN (cardiac autonomic neuropathy) is a common complication of diabetes. Meta-analyses of published data demonstrate that reduced cardiovascular autonomic function, as measured by heart rate variability, is strongly associated with an increased risk of silent myocardial ischaemia and mortality. A major problem in ischaemia-induced impairment of vascular performance in the diabetic heart is unrecognized cardiac sympathetic dysfunction. Determining the presence of CAN is based on a battery of autonomic function tests and techniques such as SPECT (single-photon emission computed tomography) and PET (positron emission tomography). Nevertheless, spectral analysis of heart rate variability seems to remain the primary technique in evaluating CAN, due to its low cost, easy use and good intra-individual reproducibility.
Translating basic science into patient therapy for ANCA-associated small vessel vasculitis
Authors: WILLIAMS Julie M. , KAMESH Lavanya , SAVAGE Caroline O. S.
Published: January 2005

ANCA (anti-neutrophil cytoplasm antibody)-associated small vessel vasculitis is an inflammatory condition associated with the production of autoantibodies to neutrophil cytoplasmic components. The disorder results in destruction of the microvasculature, infiltration of neutrophils into tissues, which is followed later by mononuclear cells, leading to injury and the formation of granulomatous lesions. Initiators for the disease are undetermined but a pro-inflammatory environment is required. Other influencing factors may include environmental triggers, genetic propensity or infectious agents. The primary cellular event in the condition involves the neutrophils, which are likely to be responsible for the majority of tissue injury. Binding of the autoantibody to neutrophils initiates cell activation via a complex intracellular signalling cascade, culminating in the release of pro-inflammatory mediators, proteolytic enzymes and reactive oxygen species. Adhesion of neutrophils to endothelial cells is observed in vitro and more investigations in this area may explain the focussing of the disease to certain vessels/tissues. Current treatment regimens have substantial toxicity. Although newer developments are an improvement there is still a pressing need for more targeted therapies, which could be provided by extrapolating information emerging from basic scientific research.
The Glycine Decarboxylase Complex is not Essential for the Cyanobacterium Synechocystis sp. Strain PCC 6803
Authors: Hagemann M. , Vinnemeier J. , Oberpichler I. , Boldt R. , Bauwe H.
Published: January 2005

Abstract: In order to investigate the metabolic importance of glycine decarboxylase (GDC) in cyanobacteria, mutants were generated defective in the genes encoding GDC subunits and the serine hydroxymethyl‐transferase (SHMT). It was possible to mutate the genes for GDC subunits P, T, or H protein in the cyanobacterial model strain Synechocystis sp. PCC 6803, indicating that GDC is not necessary for cell viability under standard conditions. In contrast, the SHMT coding gene was found to be essential. Almost no changes in growth, pigmentation, or photosynthesis were detected in the GDC subunit mutants, regardless of whether or not they were cultivated at ambient or high CO2 concentrations. The mutation of GDC led to an increased glycine/serine ratio in the mutant cells. Furthermore, supplementation of the medium with low glycine concentrations was toxic for the mutants but not for wild type cells. Conditions stimulating photorespiration in plants, such as low CO2 concentrations, did not induce but decrease the expression of the GDC and SHMT genes in Synechocystis. It appears that, in contrast to heterotrophic bacteria and plants, GDC is dispensable for Synechocystis and possibly other cyanobacteria.
Transport of Isoprenoid Intermediates Across Chloroplast Envelope Membranes
Authors: Flügge U.‐I. , Gao W.
Published: January 2005

Abstract: The common precursor for isoprenoid biosynthesis in plants, isopentenyl diphosphate (IPP), is synthesized by two pathways, the cytosolic mevalonate pathway and the plastidic 1‐deoxy‐D‐xylulose 5‐phosphate/methylerythritol phosphate (DOXP/MEP) pathway. The DOXP/MEP pathway leads to the formation of various phosphorylated intermediates, including DOXP, 4‐hydroxy‐3‐methylbutenyl diphosphate (HMBPP), and finally IPP. There is ample evidence for metabolic cross‐talk between the two biosynthetic pathways. The present study addresses the question whether isoprenoid intermediates could be exchanged between both compartments by members of the plastidic phosphate translocator (PT) family that all mediate a counter‐exchange between inorganic phosphate and various phosphorylated compounds. Transport experiments using intact chloroplasts, liposomes containing reconstituted envelope membrane proteins or recombinant PT proteins showed that HMBPP is not exchanged between the cytosol and the chloroplasts and that the transport of DOXP is preferentially mediated by the recently discovered plastidic transporter for pentose phosphates, the xylulose 5‐phosphate translocator. Evidence is presented that transport of IPP does not proceed via the plastidic PTs although IPP transport is strictly dependent on various phosphorylated compounds on the opposite side of the membrane. These phosphorylated trans compounds are, in part, also used as counter‐substrates by the plastidic PTs but appear to only trans activate IPP transport without being transported.
Sucrose Carrier RcSCR1 is Involved in Sucrose Retrieval, but not in Sucrose Unloading in Growing Hypocotyls of Ricinus communis L.
Authors: Eisenbarth D. A. , Weig A. R.
Published: January 2005

Abstract: The transport of assimilates from source to sink tissues is mediated by the phloem. Along the vascular system the phloem changes its physiological function from loading phloem to transport and unloading phloem. Sucrose carrier proteins have been identified in the transport phloem, but it is unclear whether the physiological role of these transporters is phloem unloading of sucrose or retrieval of apoplasmic sucrose back into the sieve element/companion cell complex. Here, we describe the dynamic expression of the Ricinus communis sucrose carrier RcSCR1 in the hypocotyl at different sink strengths. Our results indicate that phloem unloading in castor bean is not catalysed by the phloem loader RcSCR1. However, this sucrose carrier represents the molecular basis of the sucrose retrieval mechanism along the transport phloem, which is dynamically adjusted to the sink strength. As a consequence, we assume that other release carrier(s) exist in sink tissues, such as the hypocotyl, in R. communis.
Inheritance of a Recessive Transgene‐Associated Character Controlling Albinism in Transgenic Bean (Phaseolus vulgaris L.)
Authors: Soares A. , Romano E. , Neiva S. , De Capdeville G. , Vianna G. R. , Rech E. L. , Aragão F. J. L.
Published: January 2005

Abstract: We identified a transgenic line exhibiting albinism during our work to introduce genes through genetic engineering in dry bean (Phaseolus vulgaris). The transgenic mother plant (R0) presented a normal phenotype and generated albino and normal green plants in the first generation (R1). The segregation ratio of the albino character in the R1 and R2 generations fitted the expected ratio for a character controlled by a single recessive gene linked to a foreign gus gene, suggesting that albinism could be a consequence of insertional mutation caused by introduction of the exogenous gene. Analysis by electron microscope revealed that the albino cells possessed no chloroplasts and a greater number of mitochondria when compared to normal green plants. This transgenic bean line may be used in understanding the genetic control of chloroplast genesis, for acquiring additional knowledge of genomic structure or in physiological studies. This is the first described transgene‐associated mutant bean plant.