bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical observations of the MLT, latitude and size of pulsed ionospheric flows with the CUTLASS Finland radar
Authors: Provan G. , Yeoman T. K.
Published: June 2005

Abstract. A study has been performed on the occurrence of pulsed ionospheric flows as detected by the CUTLASS Finland HF radar. These flows have been suggested as being created at the ionospheric footprint of newly-reconnected field lines, during episodes of magnetic flux transfer into the terrestrial magnetosphere (flux transfer events or FTEs). Two years of both high-time resolution and normal scan data from the CUTLASS Finland radar have been analysed in order to perform a statistical study of the extent and location of the pulsed ionospheric flows. We note a great similarity between the statistical pattern of the coherent radar observations of pulsed ionospheric flows and the traditional low-altitude satellite identification of the particle signature associated with the cusp/cleft region. However, the coherent scatter radar observations suggest that the merging gap is far wider than that proposed by the Newell and Meng model. The new model for cusp low-altitude particle signatures, proposed by Lockwood and Onsager and Lockwood provides a unified framework to explain the dayside precipitation regimes observed both by the low-altitude satellites and by coherent scatter radar detection.Key words. Magnetospheric physics (magnetosphere · ionosphere interactions; plasma convection; solar wind-magnetosphere interactions)
Radiative forcing by contrails
Authors: Meerkötter R. , Schumann U. , Doelling D. R. , Minnis P. , Nakajima T. , Tsushima Y.
Published: June 2005

Abstract. A parametric study of the instantaneous radiative impact of contrails is presented using three different radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treated as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmosphere. The ice water content is varied as a function of ambient temperature. The model atmospheres include tropical, mid-latitude, and subarctic summer and winter atmospheres. Optically thin contrails cause a positive net forcing at top of the atmosphere. At the surface the radiative forcing is negative during daytime. The forcing increases with the optical depth and the amount of contrail cover. At the top of the atmosphere, a mean contrail cover of 0.1% with average optical depth of 0.2 to 0.5 causes about 0.01 to 0.03 Wm-2 daily mean instantaneous radiative forcing. Contrails cool the surface during the day and heat the surface during the night, and hence reduce the daily temperature amplitude. The net effect depends strongly on the daily variation of contrail cloud cover. The indirect radiative forcing due to particle changes in natural cirrus clouds may be of the same magnitude as the direct one due to additional cover.Key words. Atmospheric composition and structure (aerosols and particles) · Meteorology and atmospheric dynamics (climatology · radiative processes)
Properties and origin of energetic particles at the duskside of the Earth's magnetosheath throughout a great storm
Authors: Sarafopoulos D. V. , Athanasiu M. A. , Sarris E. T. , Yamamoto T. , Kokubun S.
Published: June 2005

Abstract. We study an interval of 56 h on January 16 to 18, 1995, during which the GEOTAIL spacecraft traversed the duskside magnetosheath from  X @ -15 to -40 RE and the EPIC/ICS and EPIC/STICS sensors sporadically detected tens of energetic particle bursts. This interval coincides with the expansion and growth of a great geomagnetic storm. The flux bursts are strongly dependent on the magnetic field orientation. They switch on whenever the Bz component approaches zero (Bz @ 0 nT). We strongly suggest a magnetospheric origin for the energetic ions and electrons streaming along these "exodus channels". The time profiles for energetic protons and "tracer" O+ ions are nearly identical, which suggests a common source. We suggest that the particles leak out of the magnetosphere all the time and that when the magnetosheath magnetic field connects the spacecraft to the magnetotail, they stream away to be observed by the GEOTAIL sensors. The energetic electron fluxes are not observed as commonly as the ions, indicating that their source is more limited in extent. In one case study the magnetosheath magnetic field lines are draped around the magnetopause within the YZ plane and a dispersed structure for peak fluxes of different species is detected and interpreted as evidence for energetic electrons leaking out from the dawn LLBL and then being channelled along the draped magnetic field lines over the magnetopause. Protons leak from the equatorial dusk LLBL and this spatial differentiation between electron and proton sources results in the observed dispersion. A gradient of energetic proton intensities toward the ZGSM = 0 plane is inferred. There is a permanent layer of energetic particles adjacent to the magnetosheath during this interval in which the dominant component of the magnetic field was Bz.Key words. Magnetospheric physics (magnetosheath; magnetotail boundary layers; storms and substorms)
The ionospheric signature of transient dayside reconnection and the associated pulsed convection return flow
Authors: Milan S. E. , Lester M. , Greenwald R. A. , Sofko G.
Published: June 2005

Abstract. Three SuperDARN coherent HF radars are employed to investigate the excitation of convection in the dayside high-latitude ionosphere in response to transient reconnection occurring in the cusp region. This study demonstrates the existence of transient antisunward-propagating backscatter features at the expected location of the ionospheric footprint of the cusp region, which have a repetition rate near 10 min. These are interpreted as the ionospheric signature of flux transfer events. Moreover, transient sunward-propagating regions of backscatter are observed in the convection return flow regions of both the pre- and post-noon sectors. These patches are observed to propagate towards the noon sector from at least as far around the auroral zone as 07 MLT in the pre-noon sector and 17 MLT in the post-noon sector, travelling with a velocity of approximately 1.5 to 2 km s-1. These return flow patches have a repetition rate similar to that of the transient features observed at local noon. While providing supporting evidence for the impulsive nature of convection flow, the observation of sunward-propagating features in the return flow region is not consistent with current conceptual models of the excitation of convection.Key words. Ionosphere (plasma convection) · Magnetospheric physics (magnetopause · cusp · and boundary layers; magnetosphere-ionosphere interactions)
Parametric decay of beam-driven Langmuir wave and enhanced ion-acoustic fluctuations in the ionosphere: a weak turbulence approach
Authors: Forme F. R. E.
Published: June 2005

Abstract. We present a model that describes the decay of beam generated Langmuir waves into ion-acoustic waves in the topside ionosphere. This calculation is done within the frame of the weak turbulence approximation. We study the spectral signature of such a process as seen by a VHF incoherent scatter radar. An incoherent scatter (IS) spectrum is characterized by two maxima at kradar and -kradar, the right and left ion lines respectively. It is shown that, for reasonable beam parameters, the parametric decay of beam-generated Langmuir waves can enhance either the right, the left or both ion lines simultaneously. The shape of the spectrum can change drastically on time scale of about 0.1 to 1 s. The role of the beam parameter as well as the ionospheric parameters is also investigated. For a given beam number density, the beam energy or the background density are important to trigger either the left or the right ion line. A large energy spread of the beam or low electron collision frequencies can explain the simultaneous observations of the left and the right ion line. The importance of the electron collision frequency can explain the altitude distribution of the coherent echoes observed by incoherent scatter radars.Key words. Ionosphere (plasma waves and instabilities) · Space plasma physics (waves and instabilities; wave-wave interactions)
On the usefulness of E region electron temperatures and lower F region ion temperatures for the extraction of thermospheric parameters: a case study
Authors: St.-Maurice J.-P. , Cussenot C. , Kofman W.
Published: June 2005

Abstract. Using EISCAT data, we have studied the behavior of the E region electron temperature and of the lower F region ion temperature during a period that was particularly active geomagnetically. We have found that the E region electron temperatures responded quite predictably to the effective electric field. For this reason, the E region electron temperature correlated well with the lower F region ion temperature. However, there were several instances during the period under study when the magnitude of the E region electron temperature response was much larger than expected from the ion temperature observations at higher altitudes. We discovered that these instances were related to very strong neutral winds in the 110-175 km altitude region. In one instance that was scrutinized in detail using E region ion drift measurement in conjunction with the temperature observations, we uncovered that, as suspected, the wind was moving in a direction closely matching that of the ions, strongly suggesting that ion drag was at work. In this particular instance the wind reached a magnitude of the order of 350 m/s at 115 km and of at least 750 m/s at 160 km altitude. Curiously enough, there was no indication of strong upper F region neutral winds at the time; this might have been because the event was uncovered around noon, at a time when, in the F region, the E×B drift was strongly westward but the pressure gradients strongly northward in the F region. Our study indicates that both the lower F region ion temperatures and the E region electron temperatures can be used to extract useful geophysical parameters such as the neutral density (through a determination of ion-neutral collision frequencies) and Joule heating rates (through the direct connection that we have confirmed exists between temperatures and the effective electric field).Key words. Ionosphere (auroral ionosphere; ionosphere atmosphere interactions; plasma temperature and density)
Internal waves and temperature fronts on slopes
Authors: Thorpe S. A. , Lemmin U.
Published: June 2005

Abstract. Time series measurements from an array of temperature miniloggers in a line at constant depth along the sloping boundary of a lake are used to describe the `internal surf zone' where internal waves interact with the sloping boundary. More small positive temperature time derivatives are recorded than negative, but there are more large negative values than positive, giving the overall distribution of temperature time derivatives a small negative skewness. This is consistent with the internal wave dynamics; fronts form during the up-slope phase of the motion, bringing cold water up the slope, and the return flow may become unstable, leading to small advecting billows and weak warm fronts. The data are analysed to detect `events', periods in which the temperature derivatives exceed a set threshold. The speed and distance travelled by `events' are described. The motion along the slope may be a consequence of (a) instabilities advected by the flow (b) internal waves propagating along-slope or (c) internal waves approaching the slope from oblique directions. The propagation of several of the observed 'events' can only be explained by (c), evidence that the internal surf zone has some, but possibly not all, the characteristics of the conventional 'surface wave' surf zone, with waves steepening as they approach the slope at oblique angles.Key words. Oceanography: general (benthic boundary layers; limnology), Oceanography: physical (internal and inertial waves)
Changes of the first Schumann resonance frequency during relativistic solar proton precipitation in the 6 November 1997 event
Authors: Roldugin V. C. , Maltsev Ye. P. , Vasiljev A. N. , Vashenyuk E. V.
Published: June 2005

Abstract. The variations of the first mode of Schumann resonance are analyzed using data from Kola peninsula stations during the solar proton event of 6 November 1997. On this day the intensive flux of energetic protons on GOES-8 and the 10% increase of the count rate of the neutron monitor in Apatity between 1220 and 2000 UT were preceded by a solar X-ray burst at 1155 UT. This burst was accompanied by a simultaneous increase of the Schumann frequency by 3.5%, and the relativistic proton flux increase was accompanied by 1% frequency decrease. These effects are explained by changes of the height and dielectric permeability of the Earth-ionosphere cavity.Key words. Ionosphere (ionospheric disturbances; solar radiation and cosmic ray effects) · Radio science (ionospheric propagation)
Stratospheric background aerosol and polar cloud observations by laser backscattersonde within the framework of the European project "Stratospheric Regular Sounding"
Authors: Adriani A. , Cairo F. , Pulvirenti L. , Cardillo F. , Viterbini M. , Di Donfrancesco G. , Pommereau J. P.
Published: June 2005

Abstract. The Stratospheric Regular Sounding project was planned to measure regularly the vertical profiles of several tracers like ozone, water vapor, NOx, ClOx and BrOx radicals, aerosol, pressure and temperature, at three latitudes, to discriminate between the transport and photochemical terms which control their distribution. As part of this project, the "Istituto di Fisica dell'Atmosfera" launched nine laser backscattersondes (LABS) on board stratospheric balloons to make observations of background aerosol and PSCs. LABS was launched with an optical particle counter operated by the University of Wyoming. Observations have been performed in the arctic, mid-latitudes and tropical regions in different seasons. Polar stratospheric clouds have been observed in areas inside and outside the polar vortex edge. A background aerosol was observed both in mid-latitudes and in arctic regions with a backscattering ratio of 1.2 at 692 nm. Very stratified aerosol layers, possibly transported into the lower stratosphere by deep convective systems, have been observed in the lower stratosphere between 20 and 29 km in the tropics in the Southern Hemisphere. Key words. Atmospheric composition and structure (aerosols and particles; middle atmosphere – composition and chemistry; instruments and techniques)
Study of the magnetic turbulence in a corotating interaction region in the interplanetary medium
Authors: Valdés-Galicia J. F. , Caballero R. A.
Published: June 2005

Abstract. We study the geometry of magnetic fluctuations in a CIR observed by Pioneer 10 at 5 AU between days 292 and 295 in 1973. We apply the methodology proposed by Bieber et al. to make a comparison of the relative importance of two geometric arrays of vector propagation of the magnetic field fluctuations: slab and two-dimensional (2D). We found that inside the studied CIR this model is not applicable due to the restrictions imposed on it. Our results are consistent with Alfvenic fluctuations propagating close to the radial direction, confirming Mavromichalaki et al.'s findings. A mixture of isotropic and magnetoacoustic waves in the region before the front shock would be consistent with our results, and a mixture of slab/2D and magnetoacoustic waves in a region after the reverse shock. We base the latter conclusions on the theoretical analysis made by Kunstmann. We discuss the reasons why the composite model can not be applied in the CIR studied although the fluctuations inside it are two dimensional.Key words. Solar physics · astrophysics and astronomy (magnetic fields) · Space plasma physics (turbulence; waves and instabilities)
Signatures of storm sudden commencements in geomagnetic H, Y and Z fields at Indian observatories during 1958−1992
Authors: Rastogi R. G.
Published: June 2005

Abstract. The work describes an intensive study of storm sudden commencement (SSC) impulses in horizontal (H), eastward (Y) and vertical (Z) fields at four Indian geomagnetic observatories between 1958–1992. The midday maximum of ΔH has been shown to exist even at the low-latitude station Alibag which is outside the equatorial electrojet belt, suggesting that SSC is associated with an eastward electric field at equatorial and low latitudes. The impulses in Y field are shown to be linearly and inversely related to ΔH at Annamalainagar and Alibag. The average SC disturbance vector is shown to be about 10–20°W of the geomagnetic meridian. The local time variation of the angle is more westerly during dusk hours in summer and around dawn in the winter months. This clearly suggests an effect of the orientation of shock front plane of the solar plasma with respect to the geomagnetic meridian. The ΔZ at SSC have a positive impulse as in ΔH. The ratio of ΔZ/ΔH are abnormally large exceeding 1.0 in most of the cases at Trivandrum. The latitudinal variation of ΔZ shows a tendency towards a minimum over the equator during the nighttime hours. These effects are explained as (1) resulting from the electromagnetic induction effects due to the equatorial electrojet current in the subsurface conducting layers between India and Sri Lanka, due to channelling of ocean currents through the Palk Strait and (2) due to the concentration of induced currents over extended latitude zones towards the conducting graben between India and Sri Lanka just south of Trivandrum.Key words. Interplanetary physics (interplanetary shocks) · Ionosphere (equatorial ionosphere) · Magnetospheric physics (storms and substorms)
Letter to the editorCUTLASS observations of a high-m ULF wave and its consequences for the DOPE HF Doppler sounder
Authors: Wright D. M. , Yeoman T. K.
Published: June 2005

Abstract. The CUTLASS (Co-operative UK Twin Located Auroral Sounding System) Finland HF radar, whilst operating in a high spatial and temporal resolution mode, has measured the ionospheric signature of a naturally occurring ULF wave in scatter artificially generated by the Tromsù Heater. The wave had a period of 100 s and exhibited curved phase fronts across the heated volume (about 180 km along a single radar beam). Spatial information provided by CUTLASS has enabled an m-number for the wave of about 38 to be determined. This high-m wave was not detected by the IMAGE (International Monitor for Auroral Geomagnetic Efects) network of ground magnetometers, as expected for a wave of a small spatial scale size. These observations over the first independent confirmation of the existence of the ground uncorrelated ULF wave signatures previously reported in measurements recorded from an HF Doppler sounder located in the vicinity of Tromsö. These results both demonstrate a new capability for geophysical exploration from the combined CUTLASS-EISCAT ionospheric Heater experiment, and provide a verification of the HF Doppler technique for the investigation of small scale ULF waves.Key words.  Ionosphere (ionosphere – magnetosphere interactions) . Magnetospheric physics (magnetosphere – ionosphere interactions; MHD waves and instabilities)
Introduction: The Equator-S mission
Authors: Haerendel G. , Torbert R. B. , Höfner H.
Published: June 2005

Abstract. In spite of its short operational life of only five months, the major goals of the Equator-S mission were fulfilled, except that its contribution to the ISTP science is restricted to the morning sector of the outer magnetosphere. A set of twelve papers following this introduction is a first documentation of the achievements. They span from the successful testing and operation of the most advanced and complex way of measuring electric fields in a hot plasma environment by means of electron beams, to various investigations at or near the equatorial magnetopause and in the plasma sheet.
The magnetic field experiment onboard Equator-S and its scientific possibilities
Authors: Fornacon K.-H. , Auster H. U. , Georgescu E. , Baumjohann W. , Glassmeier K.-H. , Haerendel G. , Rustenbach J. , Dunlop M.
Published: June 2005

Abstract. The special feature of the ringcore fluxgate magnetometer on Equator-S is the high time and field resolution. The scientific aim of the experiment is the investigation of waves in the 10–100 picotesla range with a time resolution up to 64 Hz. The instrument characteristics and the influence of the spacecraft on the magnetic field measurement will be discussed. The work shows that the applied pre- and inflight calibration techniques are sufficient to suppress spacecraft interferences. The offset in spin axis direction was determined for the first time with an independent field measurement by the Equator-S Electron Drift Instrument. The data presented gives an impression of the accuracy of the measurement.Key words. Magnetospheric physics (instruments and techniques) · Space plasma physics (instruments and techniques)
Testing electric field models using ring current ion energy spectra from the Equator-S ion composition (ESIC) instrument
Authors: Kistler L. M. , Klecker B. , Jordanova V. K. , Möbius E. , Popecki M. A. , Patel D. , Sauvaud J. A. , Rème H. , Di Lellis A. M. , Korth A. , McCarthy M. , Cerulli R. , Bavassano Cattaneo M. B. , Eliasson L. , Carlson C. W. , Parks G. K. , Paschmann G. , Baumjohann W. , Haerendel G.
Published: June 2005

Abstract. During the main and early recovery phase of a geomagnetic storm on February 18, 1998, the Equator-S ion composition instrument (ESIC) observed spectral features which typically represent the differences in loss along the drift path in the energy range (5–15 keV/e) where the drift changes from being E × B dominated to being gradient and curvature drift dominated. We compare the expected energy spectra modeled using a Volland-Stern electric field and a Weimer electric field, assuming charge exchange along the drift path, with the observed energy spectra for H+ and O+. We find that using the Weimer electric field gives much better agreement with the spectral features, and with the observed losses. Neither model, however, accurately predicts the energies of the observed minima.Key words. Magnetospheric physics (energetic particles trapped; plasma convection; storms and substorms)
Comparison of the posttraumatic stress disorder scale versus the clinician‐administered posttraumatic stress disorder scale in domestic violence survivors
Authors: Griffin Michael G. , Uhlmansiek Mary H. , Resick Patricia A. , Mechanic Mindy B.
Published: June 2005

The posttraumatic diagnostic scale (PDS) is a self‐report instrument for PTSD thai is simple to administer and has demonstrated good psychometric properties. We compared the PDS with the gold standard clinician administered PTSD scale (CAPS) diagnostic interview for PTSD. We assessed 138 women who were victims of domestic violence using both the PDS and the CAPS. Findings confirmed that PTSD develops at a high base rate in this sample. The PDS generally performed well in relation to the CAPS although with a tendency to overdiagnose PTSD. The findings lend further support to the use of the PDS as a diagnostic tool for PTSD but indicate that it is better at identifying survivors with PTSD than those without the disorder.
A new development in PTSD and the law: The case of Fairfax County v. Mottram
Authors: Lindahl Mary W.
Published: June 2005

The decision of the Virginia Supreme Court in Fairfax County Fire & Rescue Department v. Mottram (2002) has important implications for Workers' Compensation claims for posttraumatic stress disorder, particularly those involving emergency services personnel. A firefighter/paramedic who developed chronic, disabling PTSD after responding to a fatal fire was denied benefits because he had previously reported symptoms of the disorder, whereas the statute recognized a single traumatic incident only. The court held that PTSD resulting from multiple traumatic stressors may be considered a compensable occupational disease analogous to dermatitis developed by a flower shop employee with chronic exposure to irritating stimuli. The decision, which constitutes legal recognition of work‐related cumulative PTSD in rescue workers, provides benefits for treatment and encourages earlier treatment of traumatic stress in this group.
Interleukin‐4 downregulates TNFα‐induced IL‐8 production in keratinocytes
Authors: Raingeaud Joel , Pierre Josiane
Published: June 2005

Interleukin (IL)‐8 is a CXC chemokine induced by pro‐inflammatory cytokines such as TNFα, IL‐1β and IL‐6 in different cell types including keratinocytes. IL‐4 regulation of TNFα‐induced IL‐8 expression is cell‐type specific. In this study, we show that in the keratinocyte cell line HaCaT, IL‐4 decreases TNFα‐induced IL‐8 mRNA expression. We then investigated the mechanism of IL‐4 effect and showed that IL‐4 downregulates TNFα‐induced IL‐8 promoter activity in luciferase reporter assays. Moreover, overexpression of either the endogenous JAK inhibitor SOCS‐1 or a dominant negative form of the STAT6 transcription factor (STAT6ΔC) interferes with the IL‐4 inhibitory effect on IL‐8 promoter. Finally we demonstrate, using a NF‐κB‐dependent promoter luciferase construct that IL‐4 interferes, at least in part, with NF‐κB transcriptional activity. Overall our results suggest that IL‐4 regulates TNFα‐induced IL‐8 expression at a transcriptional level and this mechanism involves STAT6 and NF‐κB transcription factors.
IgG antibodies with peroxidase‐like activity from the sera of healthy Wistar rats
Authors: Ikhmyangan Erdenechimeg N. , Vasilenko Nataliya L. , Buneva Valentina N. , Nevinsky Georgy A.
Published: June 2005

Various catalytic antibodies or abzymes (Abzs) have been detected recently in the sera of patients and animals with many autoimmune diseases, where their presence is most probably associated with autoimmunization. Normal humans or animals usually do not contain Abzs. In contrast, polyclonal Abzs from healthy humans and animals have an intrinsic superoxide dismutase activity and catalyze formation of H2O2 (Wentworth et al., 2000, Proc. Natl. Acad. Sci. USA; 2001, Science). Here, we present the first evidence showing that highly purified native IgGs from the sera of healthy Wistar rats interact with H2O2 and possess peroxidase‐like activity. Specific peroxidase activity of IgG preparations from the sera of 10 rats varied in the range 1.6–27% as compared with that for horseradish peroxidase (100%). Antioxidant enzymes such as superoxide dismutases, catalases, and glutathione peroxidases are known to represent critical defence mechanisms for preventing oxidative modifications of DNA, proteins, and lipids. Antioxidant peroxidase activity of Abzs can also play an important role in the protection of organisms from oxidative stress as well as in oxidation of toxic compounds.
Protective role for cytosolic phospholipase A2α in autoimmune diabetes of mice
Authors: Oikawa Y. , Yamato E. , Tashiro F. , Yamamoto M. , Uozumi N. , Shimada A. , Shimizu T. , Miyazaki J.
Published: June 2005

Cytosolic phospholipase A2α (cPLA2α) plays an important role in arachidonate pathway. To investigate the contribution of cPLA2α to autoimmune diabetes, we established non‐obese diabetic (NOD) mouse, an excellent model for human type 1 diabetes, deficient in cPLA2α. These mice showed severe insulitis and a higher incidence of diabetes. In their macrophages, decreased prostaglandin E2 (PGE2) induced by cPLA2α deficiency, and the increase in production of tumor necrosis factor (TNF)‐α were observed. These results suggested that cPLA2α plays a protective role in progression of insulitis and development of autoimmune diabetes by suppression of TNF‐α production from macrophages.
A quantitative description of the activation and inhibition of CFTR by potentiators: Genistein
Authors: Moran Oscar , Zegarra-Moran Olga
Published: June 2005

The CFTR, encoded by the gene mutated in cystic fibrosis (CF) patients, is responsible for cAMP dependent chloride transport in epithelia. Substances that activate CFTR have been suggested as possible CF therapy. Most substances investigated so far exert a dual effect on the CFTR: low concentrations stimulate CFTR, whereas higher concentrations inhibit CFTR. Besides, the CFTR phosphorylation level determines the apparent affinity of the drug. We have studied the properties of genistein, the well known CFTR potentiator, by measuring apical membrane current on epithelia formed by cells stably transfected with CFTR and stimulated with different concentrations of CPTcAMP. We propose a quantitative model to describe the activatory and inhibitory effect of genistein, accounting also for the cAMP dependent activation.
Imaging drug action in schizophrenia: research update
Authors: Laruelle Marc , Abi-Dargham Anissa
Published: June 2005

Functional neuroimaging using techniques such as positron emission tomography (PET) and single photon emission computerised tomography (SPECT) provide a direct in vivo assessment of the expression and function of neuroreceptors, transporters and enzymes. This article examines the technical aspects of molecular imaging and the application of those techniques in drug development.
The promises and pitfalls of pharmacoeconomics in schizophrenia
Authors: Patel Anita
Published: June 2005

Pharmacoeconomic studies are often performed in order to evaluate the cost-effectiveness of different treatments in clinical practice. Such studies are exerting an increasingly important influence on treatment choices in all areas of medicine, including psychiatry, and reflect the desire to contain rising costs of medical care [27]. Pharmacoeconomic analyses indicating cost savings can even be a prerequisite for inclusion of a new drug on national formularies [28].
A complex trace fossil from the Spitskop Member (terminal Ediacaran–? Lower Cambrian) of southern Namibia
Authors: JENSEN S. , RUNNEGAR B. N.
Published: June 2005

Streptichnus narbonnei igen. et isp. nov., a new trace fossil from the upper part of the Spitskop Member of the Urusis Formation, southern Namibia, consists of clusters of unidirectionally curved radial elements, in which individual elements typically are composed of imbricated sickle–shaped segments somewhat comparable to those of Treptichnus pedum. Such complex trace fossils generally are found only in Cambrian or younger strata. This opens to question the position of the Ediacaran–Cambrian boundary in the Nama Group, suggesting that it may locally be within the uppermost part of the Urusis Formation, rather than at the base of the Nomtsas Formation.
Past developments and future opportunities in the design and analysis of crop experiments
Authors: EDMONDSON R. N.
Published: June 2005

A review of papers on the statistical design and analysis of experiments published in the Journal of Agricultural Science, Cambridge, over the last 100 years is presented. The development of significant ideas in the practical design of field experiments is reviewed. Some possible future developments in the design of spatial field trials and computer-aided design of experiments are discussed.
Grain yield, straw yield and economic value of tall and semi-dwarf durum wheat cultivars in Algeria
Authors: ANNICCHIARICO P. , ABDELLAOUI Z. , KELKOULI M. , ZERARGUI H.
Published: June 2005

In cereal-livestock farming systems of North Africa and West Asia the straw of durum wheat [Triticum turgidum (L.) Thell. ssp. turgidum conv. durum (Desf.) MacKey] is frequently used for feeding animals during the dry season and may enhance the sustainability and the flexibility of farming in various respects. In Algeria the average sale price per unit weight of the durum straw is around 30% of that of grain. Six tall and 18 semi-dwarf locally well-adapted cultivars were grown in the season 2000/01 at five Algerian locations representing the main durum wheat cropping areas to verify: (i) the impact of straw yield on the economic merit of cultivars for recommendation and (ii) the interest of tall v. semi-dwarf plant types for breeding. The tall material comprised four cultivars derived from local landraces and two old varieties. The semi-dwarf germplasm originated from CIMMYT, ICARDA or various Mediterranean countries. In the economic assessment the straw value was expressed in terms of grain-equivalent, defining an economic yield as: grain yield+(0·30×straw yield). The merit of individual cultivars was markedly affected by ignoring or taking into account the straw yield. On average, tall germplasm had a moderate (about 3%) but significant (P<0·02) economic advantage over semi-dwarf material as a result of much higher straw yield (+25%) and aerial biomass (+12%) and somewhat lower grain yield (−7%). However, three semi-dwarf varieties from CIMMYT were top-ranking for economic yield. They possessed outstanding aerial biomass and similar harvest index compared with the mean response of other semi-dwarf germplasm. On average, the tall germplasm showed higher grain yield stability (P<0·01), lower straw yield stability (P<0·01) and slightly higher stability of economic yield (P<0·11) than the semi-dwarf group as measured by Shukla's stability variance. Grain yield was negatively correlated with straw yield (r=−0·41, P<0·05), and was not correlated with aerial biomass, in the whole set of cultivars. However, it was not correlated with straw yield, and was positively correlated with aerial biomass (r=0·61, P<0·01), within the semi-dwarf germplasm. Information on straw yield can improve the targeting of cultivars for cereal-livestock farming systems. Breeding for these systems may target either a tall type within semi-dwarf material (i.e. a ‘tall dwarf’), or a truly tall plant type.
The aspectual system of Singapore English and the systemic substratist explanation
Authors: ZHIMING BAO
Published: June 2005

Singapore English is a contact language with a constant linguistic substratum and superstratum. It lends itself to an interesting case study on how linguistic neologisms emerge out of a pool of competing features from the typologically distinct languages active in the contact ecology. This paper investigates the aspectual system of Singapore English and that of Chinese, the main substrate language, and of English, the lexical-source language. Despite the presence of competing aspectual categories from the two languages, the aspectual system of Singapore English is essentially the Chinese system filtered through the morphosyntax of English. Substrate influence is systemic, and the competing grammatical subsystems do not mix.
A multi-dimensional approach to the category ‘verb’ in Cantonese
Authors: FRANCIS ELAINE J. , MATTHEWS STEPHEN
Published: June 2005

Cantonese exhibits a pattern of variation among verbs that has often been interpreted as distinguishing a category of adjectives or a subcategory of adjectival verbs. However, neither of these approaches takes into account the complex patterns of overlap among the purported categories or subcategories. To account for these patterns, we propose a multi-dimensional, feature-based analysis, whereby morphological, phonological, syntactic, and semantic features interact to determine the distribution of each verb. While all verbs bear the same syntactic category feature, there are other features that affect the distribution of verbs independently of syntactic category. For example, constructions that resemble adjectival constructions in other languages license the semantic classes of verbs that are permanent, gradable, and/or non-dynamic, while constructions that resemble verbal constructions in other languages license the semantic classes of verbs that are dynamic, non-gradable, and/or non-permanent. Typological implications of this analysis are also considered.
Anoplocephala perfoliataof horses – significant scope for further research, improved diagnosis and control
Authors: GASSER R. B. , WILLIAMSON R. M. C. , BEVERIDGE I.
Published: June 2005

Anoplocephala perfoliatais the commonest tapeworm parasite of horses and is incriminated as a significant cause of clinical disease (e.g., ileocaecal intussusception, caeco-caecal intussusception and/or caecal perforation), particularly in horses chronically infected with large numbers of worms. The high prevalence (~20–80%) of the parasite in some countries suggests an increased risk of clinical cases. In spite of research, there is still a paucity of information regarding the pathogenesis of the disease, the epidemiology of the parasite in different geographical regions and there are significant limitations with the diagnosis of infection. The present article provides an account of the biology, epidemiology and pathogenic effects ofA. perfoliata, the diagnosis of infection and treatment. It highlights some gaps in knowledge of the parasite and the disease it causes, and suggests opportunities for future research and prospects for improved diagnosis, prevention and control.
Differential infectivity and immunopathology in murine experimental infections by two natural clones belonging to theTrypanosoma cruziI lineage
Authors: GARZON E. , GENNA F. , BOSSENO M. F. , SIMONY-LA FONTAINE J. , RADAL M. , SERENO D. , MATHIEU-DAUDE F. , OUAISSI A. , BRENIÈRE S. F.
Published: June 2005

Immunopathology of Chagas' disease in Balb/c mice infected with 2Trypanosoma cruziclones, belonging to theT. cruziI lineage and presenting differentin vitrovirulence (P/209 cl1>SO34 cl4) was compared. In the acute phase, evading mechanisms such as parasite-induced lymphocyte polyclonal activation and T cell immunosuppression were higher in mice infected with the clone giving a higher parasitaemia (P/209 cl1). A similar increase of non-specific isotypes was observed in both infections with IgG2a prevalence. Interestingly, CD8+ cell hypercellularity and lymphocyte immunosuppression were observed during the chronic phase (245 days post-infection) in mice infected by the most virulent clone. In the same way, the parasite-specific antibody response was more intense in P/209 cl1-infected mice over the acute phase. During the chronic phase this response remarkably dropped down in SO34 cl4-infected mice exclusively. Finally, P/209 cl1-infected mice presented a more severe inflammation and tissue damage in heart and quadriceps than SO34 cl4-infected mice. This comparative study showed differences between the two clones: a higher virulencein vivobeing clearly associated with a greater ability to induce evasion mechanisms and severe tissue damage.
Mode of action of a potentially important excretory–secretory product fromGiardia lambliain mice enterocytes
Authors: SHANT J. , GHOSH S. , BHATTACHARYYA S. , GANGULY N. K. , MAJUMDAR S.
Published: June 2005

Giardia, a common enteric protozoan parasite is a well-recognized cause of diarrhoeal illness. The detailed mechanism of diarrhoea due to this infection is not well understood. A 58 kDa enterotoxin (ESP) was purified from the excretory–secretory product of the parasite. The present study was designed to investigate the mode of action of this enterotoxin ofG. lambliain mice enterocytes. An increase in cyclic adenosine monophosphate level, as well as intracellular Ca2+concentration, was observed in the ESP-triggered enterocytes. The levels of phospholipase Cγ1and inositol triphosphate were found to be upregulated. The activity of protein kinase C (PKC) in the enterocytes was also enhanced following stimulation with the ESP. An increase in the level of reactive oxygen species in ESP-stimulated cells correlated well with the decline in the activity of antioxidant enzymes (superoxide dismutase and catalase). The significantly high levels of nitrite and citrulline indicated the generation of reactive nitrogen intermediates in the ESP-triggered enterocytes. Thus, ESP could induce cross-talk among the different signal transduction pathways in the enterocytes, which could together bring about a common secretory response.
Paleohaemoproteus burmacisgen. n., sp. n. (Haemospororida: Plasmodiidae) from an Early Cretaceous biting midge (Diptera: Ceratopogonidae)
Authors: POINAR G. , TELFORD S. R.
Published: June 2005

Paleohaemoproteus burmacisgen. n., sp. n. (Haemospororida: Plasmodiidae) is described from the abdominal cavity of a female biting midge (Diptera: Ceratopogonidae) preserved in 100 million year old amber from Myanmar (Burma). The description is based on the developmental stages of oocysts and sporozoites. The fossil species differs from extant species ofHaemoproteusby its wide range of oocyst sizes, small sporozoites and occurrence in an extinct species of biting midge. Numerous sporozoites in the abdominal cavity suggest that the biting midge was an effective vector of this malarial parasite. Characters of the biting midge suggest that the host was a large, cold-blooded vertebrate. This is the earliest record of a malaria parasite and first indication that Early Cretaceous reptiles were infected with haemosporidial parasites.
Diagnosing genetically diverse avian malarial infections using mixed-sequence analysis and TA-cloning
Authors: PÉREZ-TRIS J. , BENSCH S.
Published: June 2005

Birds harbouring several malarial parasites are common in the wild, and resolving such multiple infections is important for our understanding of host–parasite relationships. We propose a simple and reasonably accurate method for detecting and resolving multiple infections, based on the analysis of parasite cytochromebDNA sequences: genetically mixed infections are first identified by double nucleotide peaks on sequence electropherograms, and later retrieved by TA-cloning. We applied this method to wild birds, and to experimentally created mixes with varying proportion of two parasites (Plasmodiumspp. andHaemoproteusspp.). In general, the method was very efficient in detecting and resolving multiple infections, but some problems were encountered. Several multiple infections were erroneously scored as simple, either because one of the parasite lineages was a better target for the primers used, or because it was much more abundant in the mix. On the other hand, single nucleotide substitutions and template switching during PCR produced artificial sequences in some clones. We discuss the utility of the method, and propose a framework for its use when screening for genetically diverse avian malarial parasites.
Comparison of manual and homogenizer methods for preparation of tick-derived stabilates ofTheileria parva: equivalence testing using anin vitrotitration model
Authors: MBAO V. , SPEYBROECK N. , BERKVENS D. , DOLAN T. , DORNY P. , MADDER M. , MULUMBA M. , DUCHATEAU L. , BRANDT J. , MARCOTTY T.
Published: June 2005

Theileria parvasporozoite stabilates are used in the infection and treatment method of immunization, a widely accepted control option for East Coast fever in cattle.T. parvasporozoites are extracted from infected adultRhipicephalus appendiculatusticks either manually, using a pestle and a mortar, or by use of an electric homogenizer. A comparison of the two methods as a function of stabilate infectivity has never been documented. This study was designed to provide a quantitative comparison of stabilates produced by the two methods. The approach was to prepare batches of stabilate by both methods and then subject them toin vitrotitration. Equivalence testing was then performed on the average effective doses (ED). The ratio of infective sporozoites yielded by the two methods was found to be 1·14 in favour of the manually ground stabilate with an upper limit of the 95% confidence interval equal to 1·3. We conclude that the choice of method rests more on costs, available infrastructure and standardization than on which method produces a richer sporozoite stabilate.
Heterogeneity in extracellular nucleotide hydrolysis among clinical isolates ofTrichomonas vaginalis
Authors: TASCA T. , BONAN C. D. , DE CARLI G. A. , SARKIS J. J. F. , ALDERETE J. F.
Published: June 2005

Trichomonas vaginalisis a parasitic protozoan that causes trichomonosis, a sexually-transmitted disease, with serious sequelae to women and men. As the host–parasite relationship is complex, it is important to investigate biochemical aspects of the parasite that contribute to our understanding of trichomonal biology and pathogenesis. Nucleoside triphosphate diphosphohydrolase 1 (NTPDase 1), which hydrolyses extracellular ATP and ADP, and ecto-5′-nucleotidase, which hyrolyses AMP, have been characterized in laboratory isolates ofT. vaginalis. Here we show that the extracellular ATP[ratio ]ADP hydrolysis ratio varies among fresh clinical isolates, which presented higher ATPase and ADPase activities than long-term-grown isolates. Growth of parasites in iron-replete and iron-depleted medium resulted in different, albeit minor, patterns in extracellular ATP and ADP hydrolysis among isolates. Importantly, some isolates had low or absent ecto-5′-nucleotidase activity, regardless of environmental conditions tested. For isolates with ecto-5′-nucleotidase activity, high- and low-iron trichomonads had increased and decreased levels of activity, respectively, compared to organisms grown in normal TYM-serum medium. This suggests a regulation in expression of either the enzyme amounts and/or activity under the control of iron. Finally, we found no correlation between the presence or absence of dsRNA virus infection among trichomonad isolates and NTPDase and ecto-5′-nucleotidase activities.
Spatial risk prediction and mapping of Schistosoma mansoni infections among schoolchildren living in western Côte d'Ivoire
Authors: RASO G. , MATTHYS B. , N'GORAN E. K. , TANNER M. , VOUNATSOU P. , UTZINGER J.
Published: June 2005

The objectives of this study were (1) to examine risk factors for Schistosoma mansoni infection among schoolchildren living in western Côte d'Ivoire, and (2) to carry forward spatial risk prediction and mapping at non-sampled locations. First, demographic and socio-economic data were obtained from 3818 children, aged 6–16 years, from 55 schools. Second, a single stool sample was examined from each child by the Kato-Katz technique to assess infection status of S. mansoni and its intensity. Third, remotely sensed environmental data were derived from satellite imagery and digitized ground maps. With these databases a comprehensive geographical information system was established. Bayesian variogram models were applied for spatial risk modelling and prediction. The infection prevalence of S. mansoni was 38·9%, ranging from 0% to 89·3% among schools. Results showed that age, sex, the richest wealth quintile, elevation and rainfall explained the geographical variation of the school prevalences of S. mansoni infection. The goodness of fit of different spatial models revealed that age, sex and socio-economic status had a stronger influence on infection prevalence than environmental covariates. The generated risk map can be used by decision-makers for the design and implementation of schistosomiasis control in this setting. If successfully validated elsewhere, this approach can guide control programmes quite generally.