bluuebunny/crossref_metadata_2025 huggingface dataset:
UV‐radiation‐induced preirradiation graft copolymerization of methacrylic acid and acrylic acid onto jute fibre
Authors: Khan Ferdous
Published: August 2004

UV‐radiation‐induced graft copolymerization of methacrylic acid and acrylic acid onto jute fibre was carried out using a preirradiation method with 1‐hydroxycyclohexyl‐phenylketone as a photoinitiator. 2‐methyl‐2‐propene 1‐sulfonic acid, sodium salt was incorporated into the grafting solution in suppressing the homopolymer/gel formation and facilitating graft copolymerization. In comparison, results showed that the type of monomer significantly influence on grafting. The results of the characterisation showed that the graft weight and the type of monomer have significant influence on the mechanical and water absorption properties in the case of grafted samples. Copyright © 2004 Society of Chemical Industry
Effect of α‐cyclodextrin on the crystallization of poly (3‐hydroxybutyrate)
Authors: He Yong , Inoue Yoshio
Published: August 2004

The effect of α‐cyclodextrin (α‐CD) on the crystallization behavior of poly(3‐hydroxybutyrate) (PHB) was investigated with polarized optical microscopy, differential scanning calorimetry, and wide‐angle X‐ray diffraction. We found that the addition of α‐CD can greatly accelerate the crystallization of PHB and that α‐CD has a potential not only to enhance the nucleation but also to accelerate the crystallization of PHB. Compared to a conventional nucleation agent, such as talc, α‐CD is a natural product and has many advantages because it is environmentally friendly and safe to humans. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3461–3469, 2004
Large melting point depression of 2–3‐nm length‐scale nanocrystals formed by the self‐assembly of an associative polymer: Telechelic, pyrene‐labeled poly(dimethylsiloxane)
Authors: Jones Bryce A. , Torkelson John M.
Published: August 2004

Large melting point depressions for organic nanocrystals, in comparison with those of the bulk, were observed in an associative polymer: telechelic, pyrene‐labeled poly(dimethylsiloxane) (Py‐PDMS‐Py). Nanocrystals formed within nanoaggregates of pyrenyl units that were immiscible in poly(dimethylsiloxane). For 5 and 7 kg/mol Py‐PDMS‐Py, physical gels resulted, with melting points exceeding 40 °C and with small‐angle X‐ray scattering peaks indicating that the crystals were nanoconfined, were 2–3 nm long, and contained roughly 18–30 pyrenyl dye end units. In contrast, 30 kg/mol Py‐PDMS‐PY was not a gel and exhibited no scattering peak at room temperature; however, after 12 h of annealing at −5 °C, multiple melting peaks were present at 5–30 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3470–3475, 2004
Two‐dimensional correlation gel permeation chromatography study of aggregate–aggregate interactions during acid‐catalyzed polymerization of triethoxysilyl‐terminated polystyrene
Authors: Suzuki Keita , Oku Jun‐Ichi , Izawa Kenichi , Okabayashi Hiro‐Fumi , Noda Isao , O'Connor Charmian J.
Published: August 2004

The three‐step polymerization of a well‐defined polymeric silane coupling agent, triethoxysilyl‐terminated polystyrene, catalyzed by acid (H3PO4), was traced as a function of the reaction time with gel permeation chromatography (GPC). Time‐resolved GPC traces collected during the polymerization process were then used to construct two‐dimensional (2D) correlation maps via generalized 2D correlation analysis. The results demonstrated that the synchronous and asynchronous 2D correlation GPC spectra directly reflected the dynamic variation of aggregate–aggregate interactions during each step of the polymerization. In particular, it was found that the formation of aggregates among the cyclic trimers (or tetramers) and monomers was critical for the preferential production of pentamers in the reaction system. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3447–3460, 2004
Phosphoproteome analysis of mouse liver using immobilized metal affinity purification and linear ion trap mass spectrometry
Authors: Jin Wen‐Hai , Dai Jie , Zhou Hu , Xia Qi‐Chang , Zou Han‐Fa , Zeng Rong
Published: August 2004

Since protein phosphorylation is a dominant mechanism of information transfer in cells, there is a great need for methods capable of accurately elucidating sites of phosphorylation. In recent years mass spectrometry has become an increasingly viable alternative to more traditional methods of phosphorylation analysis. The present study used immobilized metal affinity chromatography (IMAC) coupled with a linear ion trap mass spectrometer to analyze phosphorylated proteins in mouse liver. A total of 26 peptide sequences defining 26 sites of phosphorylation were determined. Although this number of identified phosphoproteins is not large, the approach is still of interest because a series of conservative criteria were adopted in data analysis. We note that, although the binding of non‐phosphorylated peptides to the IMAC column was apparent, the improvements in high‐speed scanning and quality of MS/MS spectra provided by the linear ion trap contributed to the phosphoprotein identification. Further analysis demonstrated that MS/MS/MS analysis was necessary to exclude the false‐positive matches resulting from the MS/MS experiments, especially for multiphosphorylated peptides. The use of the linear ion trap considerably enabled exploitation of nanoflow‐HPLC/MS/MS, and in addition MS/MS/MS has great potential in phosphoproteome research of relatively complex samples. Copyright © 2004 John Wiley & Sons, Ltd.
Adducts of N‐terminal valines in hemoglobin with isoprene diepoxide, a metabolite of isoprene
Authors: Fred C. , Cantillana T. , Henderson A. P. , Golding B. T. , Törnqvist M.
Published: August 2004

Isoprene (2‐methylbuta‐1,3‐diene) is a multi‐site carcinogen in rodents. To evaluate the role of the diepoxide metabolite (1,2:3,4‐diepoxy‐2‐methylbutane) in carcinogenesis, measurements of in vivo doses of the diepoxide are needed. The in vivo dose may be inferred from levels of reaction products with hemoglobin (Hb adducts). This report presents in vitro studies of the adduct formation by the diepoxide of isoprene with valinamide and oligopeptides as model compounds of N‐terminal valines in hemoglobin (Hb). In the reaction with valinamide it was shown that isoprene diepoxide forms as the main product a ring‐closed adduct, which is a pyrrolidine derivative [N,N‐(2,3‐dihydroxy‐2‐methyl‐1,4‐butadiyl)valinamide, MPyr‐Val]. The analysis was performed by gas chromatography/mass spectrometry (GC/MS) (EI and PICI) after acetylation. The ring‐closed adduct was also identified by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS) as the main product in the reaction between isoprene diepoxide and standard hepta‐ or (2H8)octapeptides, corresponding to the N‐terminal peptides of the α‐chains in mouse and rat Hb. These peptides, alkylated with isoprene diepoxide, to be used as internal standards and calibration standards for quantification of MPyr‐adduct levels in vitro and in vivo, were analyzed with respect to the degree of MPyr‐alkylation by two independent methods, amino acid analysis and HPLC‐UV; similar results were obtained using these methods. A method for measurement of Hb adducts as modified peptides, used earlier to measure a similar adduct to N‐terminal valines in Hb from the diepoxide of 1,3‐butadiene, has in the present work been tested for application to isoprene diepoxide. The method is based on tryptic degradation of globin and LC/ESI‐MS analysis of N‐terminal Pyr‐heptapeptides of the Hb α‐chain enriched by HPLC. MPyr‐adduct levels in isoprene diepoxide alkylated hemolysate from mouse erythrocytes incubated with different concentrations of isoprene diepoxide (2 and 10 mM) for 1 h were quantified. The adduct level was about 50 nmol/g α‐chain Hb per mM × h. From the adduct levels the rate constant of isoprene diepoxide for reaction with N‐terminal valine was calculated to be about 1.6 times faster than for diepoxybutane. Copyright © 2004 John Wiley & Sons, Ltd.
Subthalamic nucleus lesions alter basal and dopamine agonist stimulated electrophysiological output from the rat basal ganglia
Authors: Zahr Natalie May , Martin Lynn Pauline , Waszczak Barbara Lee
Published: August 2004

The subthalamic nucleus (STN) is an important link in the “indirect” striatal efferent pathway. To assess its role on basal ganglia output via the substantia nigra pars reticulata (SNr), we monitored the single unit activities of SNr neurons in chloral hydrate‐anesthetized rats 5–8 days after bilateral kainic acid lesions (0.75 μg/0.3 μl/side) of the STN. Consistent with loss of an excitatory input, the average basal firing rate of SNr neurons was significantly reduced in STN‐lesioned animals. Moreover, the lesions modified the responses of SNr neurons to individual and concurrent stimulation of striatal D1 and D2 receptors. Bilateral striatal infusions of the D1/D2 agonist apomorphine (10 μg/μl/side) into the ventral‐lateral striatum (VLS) were previously shown to cause significant increases in SNr cell firing (to 133% of baseline) in normal rats. However, in STN‐lesioned rats, identical infusions caused no overall change in SNr activity (mean, 103% of basal rates). Conversely, selective stimulation of striatal D2 receptors by bilateral co‐infusion of the D2 agonist quinpirole and the D1 antagonist SCH 23390 that previously caused little change in SNr firing in normal rats significantly inhibited their firing in STN‐lesioned rats. Finally, the modest excitatory responses of SNr neurons to selective stimulation of striatal D1 receptors by co‐infusions of SKF 82958 with the D2 antagonist YM09151‐2 were not altered by lesions of the STN. These results implicate the STN as a mediator of excitatory response of SNr neurons to D2, and mixed D1/D2, dopamine receptor agonists in normal rats, and challenge conventional views on the role of the STN and the “indirect” pathway in regulating dopamine‐stimulated output from the SNr. Synapse 54:119–128, 2004. © 2004 Wiley‐Liss, Inc.
Serotonin‐induced phase advances of SCN neuronal firing in vitro: A possible role for 5‐HT5A receptors?
Authors: Sprouse Jeffrey , Reynolds Linda , Braselton John , Schmidt Anne
Published: August 2004

Spontaneous firing rates of neurons in the suprachiasmatic nuclei (SCN) follow a consistent pattern, peaking near the midpoint of the light phase in a 12:12 light/dark schedule, and repeating this brief period of increased activity in subsequent circadian cycles. These carefully timed fluctuations reflect the output signal of the SCN, long recognized as the site of the endogenous biological clock in mammals. In rat hypothalamic slices, bath incubations of 8‐OH‐DPAT had previously been shown to elicit phase advances when applied at ZT6 (or 6 h following the onset of light), an action that could readily be attributed to 5‐HT7 receptor activation. The present studies set out with the simple goal of establishing that the same receptor mechanism was responsible for the phase‐shifting actions of 5‐HT itself. Surprisingly, the phase advances elicited by 5‐HT (0.5 μM, 1 h) at ZT6 were reduced by one 5‐HT7 antagonist, ritanserin (10 μM), but not by another, mesulergine (10 μM). Receptor binding studies demonstrated a 25‐fold greater affinity of ritanserin for h5‐HT5A sites compared to mesulergine (Ki = 71 nM vs. 1,800 nM), an observation suggestive of a 5‐HT5A mechanism for 5‐HT and consistent with earlier observations of robust labeling of 5‐HT5A sites in the SCN. 5‐HT generated by the addition of L‐tryptophan (10 μM, 1 h) to the slices displayed the same pattern of sensitivity, that is, blockade by ritanserin but not by mesulergine. Rp‐cAMPS, a cAMP antagonist, failed to block the phase shifts elicited by 5‐HT at a concentration (1 μM) previously shown to be effective against 8‐OH‐DPAT‐induced phase shifts, in keeping with the proposed negative coupling of 5‐HT5A receptors to cAMP production. Taken together, these results suggest that activation of both 5‐HT5A and 5‐HT7 receptors can produce phase advances of the circadian clock in vitro when they occur during mid‐subjective day. Synapse 54:111–118, 2004. © 2004 Wiley‐Liss, Inc.
Preconceptions versus experience of transvaginal ultrasonography in older women
Authors: Kew F. M. , Whittaker V. J. , Cruickshank D. J.
Published: August 2004

Objective

To determine whether women find that having a transvaginal ultrasound scan is better or worse than they had expected.

Methods

Fifty‐four consecutive women in an ovarian cancer screening trial filled in linked questionnaires before and after having a transvaginal ultrasound scan.

Results

The women found that having a transvaginal scan was less painful (P = 0.003) and less embarrassing (P = 0.001) than they had expected. They found it less uncomfortable than expected in comparison to having mammography (P = 0.013) or a cervical smear (P = 0.004).

Conclusions

Women attending for a transvaginal scan can be reassured that it will not be as painful or embarrassing as they fear, and that it is not as uncomfortable as having mammography or a cervical smear. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Anatomy and formation of oblique continental collision: South Falkland basin
Authors: Bry Madeleine , White Nicky , Singh Satish , England Richard , Trowell Carl
Published: August 2004

The South Falkland basin is a partially filled Cenozoic foreland basin located south of the Falkland Plateau. It was formed by flexure of this southern edge of the South American plate when the load represented by Burdwood Bank collided. This continental fragment belongs to the predominantly oceanic Scotia plate. Flexure probably started in early Cenozoic times and has continued to the present day. The whole region is submarine and so the detailed stratigraphy and structure of the basin has been well imaged by seismic reflection profiling. The clarity of this imagery has made analysis of structures within the collision zone possible. The plate boundary itself is an active oblique thrust fault which has controlled the growth of a frontal fold. There is evidence for older phases of thrusting and folding further south. Within and beneath the sediments which blanket the flexed South American plate, normal faulting occurs on a variety of scales. Episodes of stratigraphic growth associated with the largest of these faults demonstrates that they were active during flexural bending. We have modeled the development of the South Falkland basin using two different approaches, both of which are based upon the simplest elastic model. Inverse modeling of free‐air gravity and bathymetric profiles suggest that the elastic thickness of the loaded crust is 5–20 km. A complementary approach based upon the spectral analysis of free‐air gravity and bathymetry shows that the elastic thickness is 15 ± 5 km. Both techniques indicate that the flexed continental lithosphere is weak, a conclusion supported by the presence of normal faults within the flexed plate. A small increase in elastic thickness from west to east appears consistent with a change in the density and penetration of normal faulting.
TOPEX/Poseidon observations of mesoscale eddies over the Subtropical Countercurrent: Kinematic characteristics of an anticyclonic eddy and a cyclonic eddy
Authors: Hwang Cheinway , Wu Chau‐Ron , Kao Ricky
Published: August 2004

Relative dynamic heights and geostrophic fields were derived from TOPEX/Poseidon altimetry data and then used to track mesoscale eddies over the Subtropical Countercurrent (STCC). The radii, centers, vorticities, shearing deformation rates, stretching deformation rates, divergences, and center velocities of all identified eddies over the STCC were determined using a model that assumes constant velocity gradients. Most eddies are concentrated in a zonal band near 22°N, and there is an interannual variation in the number of eddies. A case study was made for a cyclonic eddy and an anticyclonic eddy, with time series of eddy kinematic parameters computed. Both eddies survive for ∼220 days and propagate westward along over 22°N–24°N to reach the Kuroshio Current east coast of Taiwan, where the eddies were dissipated and in turn affected the Kuroshio Current in many ways. Sea surface temperature data and drifter data confirm the existence of these two eddies. The radii of both eddies vary and their shapes are mostly elliptical during propagation. The anticyclonic eddy propagated almost westward with oscillating north‐south components, and the mean speed is 8.3 km/day. The cyclonic eddy moved southwestward before reaching 130°E and then moved northwestward, with a mean speed of 7.6 km/day. The propagations of these two eddies are basically consistent with the standard theory of eddy propagation but with larger speeds. The propagating direction could be altered while passing steep bottom topography or merging with the other eddies.
The vertical structure of OH‐HO2‐RO2 chemistry in the nocturnal boundary layer: A one‐dimensional model study
Authors: Geyer Andreas , Stutz Jochen
Published: August 2004

Elevated OH and peroxy radical levels have recently been observed in the nocturnal boundary layer (NBL). Despite the possible importance of OH for the gas phase and particulate composition, the source of these ROx radicals at night is currently unclear. To investigate the influence of vertical mixing on nocturnal ROx chemistry, calculations with a one‐dimensional chemical transport model were performed. The model predicts distinct vertical profiles for all ROx radical species during the night, with a pronounced RO2 maximum aloft and maxima of HO2 and OH closer to the ground. We conceptualize our results by distinguishing three chemical regimes in the NBL: (1) In the unreactive ground layer, which only forms at high NO emissions and strong vertical stabilities, OH chemistry is suppressed by high NO levels. (2) The upper layer, located in the upper NBL, is decoupled from the NO emissions at the ground. Ozonolysis of volatile organic compounds (VOCs) leads to the formation of ∼105 molecules cm−3 of OH. The RO2 maximum develops in the lower part of the upper layer by the elevated O3/NO3 + VOC reaction rates. (3) In the reactive mixing layer, in the height interval between the upper layer and the ground layer, RO2 and HNO4 (as HO2 reservoir) from the upper layer are mixed with NO from the ground layer. The active radical propagation chain leads to distinctive maxima of HO2 and OH (up to several 106 molecules cm−3) in this layer. The OH radicals in the reactive mixing layer can contribute up to 43% to the nocturnal VOC oxidation, illustrating that OH chemistry can be important even at night. Our model simulations show that vertical transport can redistribute ROx radicals in the NBL, acting as an important radical source in the lowest few meters of the atmosphere.
Water market transfers in South Africa: Two case studies
Authors: Nieuwoudt W. L. , Armitage R. M.
Published: August 2004

Statistical analyses (discriminant, logit, and principal components) of water transfers in the Lower Orange River showed that water rights were transferred to farmers with the highest return per unit of water applied, those producing table grapes, and with high‐potential arable “outer land” without water rights. Only unused water (sleeper right) was transferred, while water saved (through adoption of conservation practices) was retained possibly for security purposes. A second study in the Nkwaleni Valley in northern KwaZulu‐Natal found that no water market had emerged despite the scarcity of water in the area. No willing sellers of water rights existed. Demand for institutional change to establish tradable water rights may take more time in the second area since crop profitability in this area is similar for potential buyers and nonbuyers. Transaction costs appear larger than benefits from market transactions. Farmers generally use all their water rights in the second area and retain surplus water rights as security against drought because of unreliable river flow. This study indicates that these irrigation farmers are highly risk averse (downside risk). Government policies that increase the level of risk and reduce security of licenses are estimated to have a significant effect on future investment in irrigation. In an investment model the following variables explain future investment: expected profits, liquidity, risk aversion (Arrow‐Pratt), and security of water use rights. The study is seen in the light of the New South African Water Act of 1998. According to this act, the ownership of water in South Africa has changed from private to public. This reform may not impede the development of water markets in South Africa since in the well‐developed water markets of the United States, western states claim ownership of water within their boundaries. All states in the western United States allow private rights in the use of water to be established and sold.
Enhancement of gravity wave activity observed during a major Southern Hemisphere stratospheric warming by CHAMP/GPS measurements
Authors: Venkat Ratnam M. , Tsuda T. , Jacobi C. , Aoyama Y.
Published: August 2004

Using temperature profiles measured by CHAMP/GPS occultations we analyzed the gravity wave activity during the major sudden stratospheric warming (SSW) occurred in the Southern Hemisphere (SH) in late winter/spring of 2002, which for the first time split the polar vortex into two parts. The observed temperatures show a rapid poleward moving increase with a maximum of about 25–30 K with respect to the undisturbed winter conditions, and a reversal of the latitudinal gradients at 30 km and below within 15 days (September 15–30). During this time gravity wave energy (potential energy, Ep) became 3 times higher than usual. This enhancement mostly occurred near the edge and outside the cold polar vortex, but not inside the vortex. We discuss the observed event with potential interaction of gravity waves, planetary waves and the mean circulation during the stratospheric warming.
Comparison of MISR and AERONET aerosol optical depths over desert sites
Authors: Martonchik J. V. , Diner D. J. , Kahn R. , Gaitley B. , Holben B. N.
Published: August 2004

Comparisons of the Multi‐angle Imaging SpectroRadiometer (MISR) aerosol optical depths (AOD) with those of the AErosol RObotic NETwork (AERONET) were made at four desert sites, covering a two‐year time period from December 2000 to November 2002. The two data sets show good correlation with no obvious systematic biases or trends, demonstrating MISR's ability to retrieve reliable visible and near infrared AOD over surfaces with relatively high reflectance. For MISR AOD obtained at 17.6 km spatial resolution, the estimated uncertainty is about 0.08. When the spatial resolution was degraded to 52.8 km, the estimated AOD uncertainty decreased to about 0.05. Year‐long time‐series comparisons of MISR and AERONET AOD at the four desert sites showed that MISR can quantitatively capture the temporal nature of strong dust activity in desert regions.
Dust escape from Io
Authors: Flandes Alberto
Published: August 2004

The Dust ballerina skirt is a set of well defined streams composed of nanometric sized dust particles that escape from the Jovian system and may be accelerated up to ≥200 km/s. The source of this dust is Jupiter's moon Io, the most volcanically active body in the Solar system. The escape of dust grains from Jupiter requires first the escape of these grains from Io. This work is basically devoted to explain this escape given that the driving of dust particles to great heights and later injection into the ionosphere of Io may give the particles an equilibrium potential that allow the magnetic field to accelerate them away from Io. The grain sizes obtained through this study match very well to the values required for the particles to escape from the Jovian system.
Validation of a global reanalysis model in representing synoptic–scale eddies using scatterometer data: A case study
Authors: Peng Ge
Published: August 2004

A synoptic‐scale cyclonic eddy was captured in the National Centers for Environmental Prediction (NCEP) global reanalysis surface winds in the Bay of Bengal and the Arabian Sea in October 1996. The eddy was formed in the Bay of Bengal in the middle of October 1996. It migrated across southern India, entered the Arabian Sea, and moved along the west coast of India before it turned and propagated across the Arabian Sea toward the Somali coast. The eddy eventually dissipated near Socotra in early November. The performance of the model winds is validated using the National Aeronautics and Space Administration Scatterometer (NSCAT) data along swath measurements. The model is able to resolve the eddy. The results compare well with observations in circulation intensity but differ in eddy center locations and, therefore, in westward propagation speeds in the late stage of the eddy life cycle.
Time of flight and direction of arrival of HF radio signals received over a path along the midlatitude trough: Observations
Authors: Siddle D. R. , Stocker A. J. , Warrington E. M.
Published: August 2004

Measurements of the time‐of‐flight, direction of arrival, and Doppler spread are presented for HF radio signals radiated on six frequencies between 4.6 and 18.4 MHz received over a subauroral path oriented along the midlatitude trough between Sweden and the UK. During the day, the signals usually arrived from the great circle direction whereas at night, especially during the winter and equinoctial months; the signals on frequencies between 7.0 and 11.1 MHz often arrived from directions well displaced from the great circle direction. In summer the deviations tended to be smaller (<5°) than those observed during the other seasons (several tens of degrees). The deviations were mainly to the north and often lasted all night, with the time of flight initially decreasing and then increasing, showing an approach and then recession of the reflection point. Southerly deviations were much less coherent and less frequent.
Semianalytical uncertainty estimation of well catchments: Conditioning by head and transmissivity data
Authors: Stauffer Fritz , Hendricks Franssen Harrie‐Jan , Kinzelbach Wolfgang
Published: August 2004

The goal of the investigations is to estimate the uncertainty in the location of two‐dimensional, steady state catchments of pumping wells due to the uncertainty of the spatially variable transmissivity field. The uncertainty is evaluated conditional to measured transmissivity and head data. The uncertainty bandwidth of the catchment boundary is approximated in first order by formulating the conditional transversal second moment of the particle displacements along the expected mean particle trajectory. However, empirical relationships have to be provided for the estimation of the uncertainty in the location of stagnation points. Applications of the approach are presented for a synthetic test case with two arrangements of measurement stations. The results are compared with those from conditional numerical Monte Carlo simulations. The comparison allows an assessment of the accuracy and the applicability of the method. The approximation corresponds quite well with the Monte Carlo simulations.
Introduction to special section on River Basin Management: Economics, Management, and Policy
Authors: Saleth R. Maria
Published: August 2004

The literature on river basin management is growing with an expanding coverage of issues and basins and an increasing refinement of approaches and methods. Still, many old questions remain unresolved, while new concerns are emerging, especially on the economic, managerial, and policy dimensions of river basin management. This special section brings together a set of papers that addresses some of these issues in the context of different basins around the world by adopting varying perspectives and approaches. This introductory paper prepares the stage and context for the special section with a brief review of existing literature and a quick overview of the papers included in the special section. Since the review indicates the major focus and coverage as well as the weak spots and gaps in present research, it provides context both to gauge the significance of the selected papers and to indicate the key areas requiring attention in future research on the subject of river basin management.
A detailed simulation for the transmission spectrum of hot aluminium plasma
Authors: Jin Fengtao , Zeng Jiaolong , Yuan Jianmin
Published: August 2004

The experimental transmission spectrum [Jiamin Yang et al., Phys. Plasmas 10, 4881 (2003)] of hot aluminium plasma is simulated by using a detailed term accounting model. The fine absorption structures are reproduced reasonably well for both the absorption strength and the line positions. The discrepancies between the detailed simulation and the experiment show that the temperature gradient exists in the experimental sample. By fitting the measured transmission spectrum with the variation of the population of the ion stage, it is concluded that the experimental transmission spectrum was obtained mainly at the temperature of about 65 eV but overlapped by some lower temperature spectra of even down to 35 eV. The relative strength of the fine absorption lines within one stage of the ion cannot be reproduced accurately without considering the non-Boltzmann distributions among the energy levels of the ion.
Edge transport and the low-to-high transition in tokamaks with D-shaped magnetic flux surfaces
Authors: Kleva Robert G. , Guzdar Parvez N. , Dorland W.
Published: August 2004

Nonlinear, three-dimensional numerical simulations of finite-β drift-ballooning turbulence in the edge of tokamaks with D-shaped magnetic flux surfaces are presented. The simulations are based on the reduced Braginskii equations. The turbulent transport in tokamaks with D-shaped magnetic flux surfaces is directly compared to that in tokamaks with circular magnetic flux surfaces. The energy flux can be extremely different depending on the shape of the magnetic flux surfaces. While a tokamak with circular flux surfaces exhibits exceedingly poor confinement, an otherwise identical tokamak with D-shaped flux surfaces is in the high (H) mode where the transport rate is small. The magnitude of the energy flux in these two cases differs by a multiplicative factor larger than 1000.
Inferring the capsule-absorbed radiation energy from experimental hohlraum radiation temperature
Authors: Chang Tieqiang , Wang Guangyu , Li Yunsheng , Sheng Jiatian , Pei Wenbing
Published: August 2004

For indirect laser fusion, the implosion is driven by the fusion capsule-absorbed radiation energy emitted by laser-produced plasma. However, the absorbed energy could hardly be directly measured experimentally and usually would require numerical simulation. This paper puts forward a method by which the capsule-absorbed radiation energy can be inferred from the measured time-dependent radiation temperature. In the method, the capusle-absorbed radiation energy is seen as an effective radiation energy loss and should be reflected in the experimental radiation temperature. Furthermore, it is not necessary to know what materials the capsule is made of or how it is constructed.
Macro-scale instability of the ion shell distribution function in the divergent solar wind
Authors: Shevchenko Valentin , Galinsky Vitaly , Sagdeev Roald , Winske Dan
Published: August 2004

As a result of cyclotron interaction with Alfvén waves propagating from the sun, pitch angle diffusion of resonant particles takes place and a shell-like distribution function of resonant ions is formed at each distance from the sun. Stability of the solar wind ion shell-like distribution function with respect to excitation of waves at larger distances is addressed. It is shown in linear approximation, that in the case when the phase velocity of Alfvén waves decreases with distance, ions with shell distribution excite outward propagating Alfvén waves with smaller phase velocities when they advance to larger distances. The nonlinear dynamics of the wave spectrum as well as the evolution of the ion distribution function are studied. The characteristic spectrum at the high-frequency edge of the magnetohydrodynamic fluctuations is explained.
Structure of the edge density pedestal in tokamaks
Authors: Stacey Weston M.
Published: August 2004

A “first-principles” model for the structure of the edge density pedestal in tokamaks between or in the absence of edge localized magnetohydrodynamic instabilities is derived from ion momentum and particle conservation and from the transport theory of recycling neutral atoms. A calculation for (high) H-mode tokamak discharge parameters indicates that the equations have a self-consistent solution which has an edge pedestal in the ion density profile and sharp negative spikes in the poloidal velocity and radial electric field profiles in the edge pedestal, features characteristic of H-mode edge profiles. These sharp negative spikes in radial electric field and poloidal rotation produce a peak in the inward ion pinch velocity in the sharp gradient (pedestal) region which produces an edge particle transport barrier. The calculated magnitude of the density at the top of the pedestal and the density gradient scale length and radial electric field in the pedestal region are comparable to measured values.
Derivation of the supersymmetric Harish-Chandra integral for UOSp(k1/2k2)
Authors: Guhr Thomas , Kohler Heiner
Published: August 2004

The previous supersymmetric generalization of the unitary Harish-Chandra integral prompted the conjecture that the Harish-Chandra formula should have an extension to superspaces. We prove this conjecture for the unitary orthosymplectic supermanifold UOSp(k1/2k2). To this end, we construct and solve an eigenvalue equation.
An Ising model with three competing interactions on a Cayley tree
Authors: Ganikhodjaev N. N. , Pah C. H. , Wahiddin M. R. B.
Published: August 2004

In this paper we consider an Ising model with three competing restricted interactions on the Cayley tree J2(J3). The translation invariant and periodic Gibbs measures for these models are investigated and the problem of the phase transition in these classes is solved.
Semiclassical limit for multistate Klein–Gordon systems: almost invariant subspaces, and scattering theory
Authors: Nenciu Gheorghe , Sordoni Vania
Published: August 2004

By using the method of Helffer and Sjöstrand to construct Moyal projections, we extend the almost invariant subspace theory to the semiclassical context. Applications to the semiclassical limit for two component Klein–Gordon Hamiltonian are given. More precisely, under the conditions that the potential is analytic and its eigenvalues never cross we prove that the scattering matrix is block diagonal up to exponentially small errors. Also, we show how the existence of almost invariant subspaces leads to the existence of quasimodes with exponentially long lifetimes.
Finite size universe or perfect squash problem
Authors: Turko Ludwik
Published: August 2004

We give a physical notion to all self-adjoint extensions of the operator id/dx in the finite interval. It appears that these extensions realize different nonunitary equivalent representations of CCR and are related to the momentum operator viewed from different inertial systems. This leads to the generalization of Galilei equivalence principle and gives a new insight into the quantum correspondence rule. It is possible to get transformation laws of the wave function under Galilei transformation for any scalar potential. This generalizes the mass superselection rule. There is also given a new and general interpretation of a momentum representation of the wave function. It appears that consistent treatment of this problem leads to the time-dependent interactions and to the abrupt switching-off of the interaction.
Comparison of multiple techniques to evaluate reproductive variability in a marine bivalve: application to the scallop Pecten novaezelandiae
Authors: Williams James R. , Babcock Russell C.
Published: August 2004

Reproduction and spawning of the scallop Pecten novaezelandiae were monitored at four sites in the Hauraki Gulf, New Zealand, from July 2000 to July 2001. A visual grading system based on the macroscopic appearance of the gonad was developed and tested, and changes in visual grade, quantitative histology, and standardised gonad mass were used to describe seasonal and spatial patterns in gametogenesis and spawning. Visual grade was significantly correlated with histological and gonad mass data (r
2 = 0.74–0.87) and validated as an accurate method for measuring reproduction in P. novaezelandiae. Visual grading facilitates rapid assessment of reproductive condition and can be conducted non-destructively, thus providing a tool allowing long-term studies of individual spawning behavior in relation to environmental signals. Scallops exhibited episodic spawning, with spawning events detected in spring, summer, autumn, and even early winter. Gonad recovery and subsequent gamete development and maturation were apparent between spawnings. Within-season variability in gonad size and condition could be the result of multiple (serial) spawnings during a season. The timing of spawning varied among populations, probably reflecting differences in environmental conditions that influenced reproduction. However, the largest spawning events occurred at all sites in early summer (December/January), coincident with wind-driven upwelling conditions.
Emotional understanding in Quechua children from an agro-pastoralist village
Authors: Tenenbaum Harriet R. , Visscher Paloma , Pons Francisco , Harris Paul L.
Published: August 2004

Research on children’s understanding of emotion has rarely focused on children from nonindustrialised countries, who may develop an understanding at different ages as compared to children reared in industrialised countries. Quechua children from an agro-pastoralist village were given an adapted version of the Test of Emotion Comprehension (TEC) to assess their understanding of nine aspects of emotions. Older children performed better on the entire TEC than younger children. Eight- to 11-year-olds were more accurate in identifying emotions connected to individual desires and to a moral misdemeanour than were 4- to 7-year-olds. In addition, there was a trend for 8- to 11-year-olds to understand external causes of emotions better than 4- to 7-year-olds. Compared to British children, the Quechua children were less accurate overall. However, similar to the British children, certain aspects of emotion (e.g., recognition) were understood at younger ages than others (e.g., regulation), suggesting similar patterns in the sequence of emotional understanding despite the radical difference in cultural context. In contrast to children from industrialised settings, children from this Quechua village have little access to formal education. Moreover, Quechua children have fewer opportunities to engage in discussions about emotions with adults, which may also contribute to how well they performed on the TEC. Suggestions for improving the TEC and including a more naturalistic testing situation are made.
Book Reviews
Authors: Glomset O. , Skaane P. , Abildgaard A. , Tikkakoski T.
Published: August 2004

Radiation Exposure and Image Quality in X-ray Diagnostic Radiology. Physical Principles and Clinical Applications. By H. Aichinger, J. Dierker, S. Joite-Barfuss and M. Säbel. Springer-Verlag, Berlin, Heidelberg, 2004. ISBN 3-540- 44287-1. Hardcover. 212 pages, 199 illustrations, 78 tables, complemented by one CD-ROM. Price €79.95.

Practical MR Mammography. Edited by Uwe Fischer. Thieme Verlag, 2004. ISBN 3-13-132031-1. Hardcover. 211 pages, 398 illustrations. Price €99.00.

How Does MRI Work? An Introduction to the Physics and Function of Magnetic Resonance Imaging, by D. Weishaupt, V. D. Koechli, and B. Marincek, with contributions from K. P. Preussmann and J. M. Froelich. Springer-Verlag, Berlin, Heidelberg, 2003. ISBN 3-540-44094-1. 138 pages, 41 illustrations. Price €29.95.

Diffusion-Weighted MR Imaging of the Brain. T. Moritani, S. Ekholm, and P.-L.Westesson. Berlin, Heidelburg: Springer-Verlag, 2004. ISBN 3 540 03439 0. 229 pages, 688 figures, 11 tables. Price hardcover: €99.95.
Intracranial metastasis via transplacental (vertical) transmission of maternal small cell lung cancer to fetus: CT and MRI findings
Authors: Teksam M. , McKinney A. , Short J. , Casey S. O. , Truwit C. L.
Published: August 2004

We present the computed tomography (CT) and magnetic resonance imaging (MRI) findings of brain metastases in an unusual case of a premature, 33‐week gestational age neonate who was emergently delivered from a mother suspected of having lung cancer according to imaging performed during the third trimester of pregnancy. Owing to the presence of placental metastases noted after delivery, the fetus had initial screening with brain MRI and chest/abdomen CT as well as serial screening imaging studies during the first 5 months of life, all of which were apparently normal. However, serial examinations eventually revealed a cerebellar lesion that significantly improved after chemotherapy but recurred and enlarged within a few months. This lesion was later confirmed to be metastasis by subsequent biopsy and resection. More metastatic lesions were identified in the frontal and temporal lobes on follow‐up MRI. In the setting of aggressive maternal malignancy (without known fetal primary malignancy) an intracranial mass can, on the exceedingly rare occasion, result from maternal high‐grade malignancy and the neuroradiologist should be alerted to this phenomenon.
Myositis ossificans of psoas muscle: magnetic resonance imaging findings
Authors: Sirvanci M. , Ganiyusufoglu A. K. , Karaman K. , Tezer M. , Hamzaoglu A.
Published: August 2004

Myositis ossificans is a benign, localized, self‐limiting ossifying soft tissue mass with unknown pathogenesis. It may be confused with a malignant tumor of bone or soft tissues, especially in the early stages of the disease. In this report, we present a case of myositis ossificans affecting unilateral psoas muscle, which to our knowledge is a very uncommon location. There was no history of trauma. We describe the imaging findings and clues to early diagnosis of myositis ossificans.
An asymptomatic pulmonary hilar mass: a case report
Authors: Andrikakos P. , Gallis P. , Christopoulos A. , Flabouriaris S. , Mylona M. , Dimopoulos P. A.
Published: August 2004

Pulmonary vein varix is a rare benign abnormality, either congenital or acquired, usually presented without symptoms. It is most frequently discovered by chance on a chest radiograph, whereas computed tomography defines the special characteristics of the lesion. Angiography is considered the method of choice for final diagnosis. The authors present the first case of a patient with pulmonary vein varix accompanied by interatrial communication.
Complications following ultrasound‐guided thoracocentesis
Authors: Mynarek G. , Brabrand K. , Jakobsen J. Å. , Kolbenstvedt A.
Published: August 2004

Purpose: To retrospectively register the number and type of complications following ultrasound‐guided thoracocentesis, and to evaluate the need for routine chest X‐ray after the procedure.

Material and Methods: Complications were retrospectively registered from the radiological and clinical reports of 371 consecutive patients who had undergone thoracocentesis with a total of 711 procedures.

Results: The mean volume evacuated was 823 ml (range 0–3600 ml). Twenty (2.8%) pneumothoraces were found after 711 thoracocenteses, but in no case was chest tube drainage necessary. Hemoptysis occurred in one patient.

Conclusion: Ultrasound‐guided thoracocentesis was found to be a safe procedure. Based on these results, no reason was found to introduce an upper limit of the amount of fluid drained in one session. Routine follow‐up chest X‐ray is not justified in the absence of clinical symptoms.
Partial unilateral intracavernosal hematoma in a long‐distance mountain biker: a case report
Authors: Zandrino F. , Musante F. , Mariani N. , Derchi L. E.
Published: August 2004

We present a case of spontaneous partial unilateral hematoma of the bulb of the corpus cavernosum in a long‐mileage mountain biker. Ultrasonography, magnetic resonance imaging, and histopathological findings are described.
Alveolar echinococcosis of the liver: correlative color Doppler US, CT, and MRI study
Authors: Coşkun A. , Öztürk M. , Karahan O. I. , Erdogan N. , Işin Ş. , Güleç M.
Published: August 2004

Purpose: To determine and compare the imaging features of hepatic alveolar Echinococcosis using color Doppler US, CT, and MRI.

Material and Methods: Abdominal CT and MRI with and without contrast agents and color Doppler US were performed on seven patients with hepatic alveolar Echinococcosis. The lesions were evaluated for location, features of echogenicity, intensity and density, calcification, and vascular, hilar, and perihepatic involvement. The diagnosis was confirmed histopathologically in all patients.

Results: Six patients had solitary lesions, and one displayed multiple lesions. The lesions were generally seen as heterogeneous and hyper‐ or hypoechoic when imaged with color Doppler US, hypodense with CT, and hypointense with MRI, in comparison with the liver parenchyma. Calcification, central necrosis, and small peripheral cysts were observed in six, seven, and four patients, respectively. Vascular flow or contrast enhancement was not observed in any of the cases. A look at the respective advantages of each method reveals that calcification was best rendered visible via CT, small peripheral cysts with T2‐weighted MRI, central necrosis with CT and MRI, and perihepatic invasion with multiplanar MRI. Vascular involvement was revealed by all methods.

Conclusion: Color Doppler US, CT, and MR imaging function extremely well as complementary methods in the diagnosis of HAE. Color Doppler US should be performed in these patients owing to its ability to efficiently detect the disease. Knowledge of imaging characteristics makes it possible to radiologically ascertain an early diagnosis.
Cuff‐compression of the proximal calf to reduce venous contamination in contrast‐enhanced stepping‐table magnetic resonance angiography
Authors: Bilecen D. , Jäger K. A. , Aschwanden M. , Heidecker H. G. , Schulte A.‐C. , Bongartz G.
Published: August 2004

Purpose: To minimize venous overlay at the calf station in contrast‐enhanced three‐dimensional (3D) stepping‐table magnetic resonance angiography (MRA) using a continuous cuff‐compression technique during MR data acquisition.

Material and Methods: Within 14 months, 32 patients suffering from symptomatic peripheral arterial occlusive disease (PAOD) with a bilateral ankle‐brachial index (ABI) of 0.8 or below were consecutively enrolled in this study. Unilateral cuff‐compression of the proximal calf was applied in the study group ( n=14). The control group ( n=18) underwent no compression. All patients underwent three‐step 3D contrast‐enhanced magnetic resonance angiography (3D CE‐MRA) according to the institute's protocol. Venous contamination scores (vcs) at the calf station were blindly ranked by a 1 to 3 rating score (3=major venous contamination). The vcs values of the control group were regarded as standard. Statistical significance between both groups was evaluated with a paired t test.

Results: Symmetric venous contamination was observed within the control group with a mean vcs of 2.2±0.6 on the left side and 2.2±0.7 on the right side with Δvcsleft‐right of 0.1±0.2 ( P>0.1). In the study group, asymmetric venous contamination was determined with vcsmean=2.3±0.6 for the uncompressed side and vcsmean=1.4±0.5 for the compressed side and a Δvcsuncomp‐comp of 0.9±0.5 ( P<0.00005). The control group and the uncompressed side of the study group showed no significant difference in venous contamination ( P>0.1).

Conclusion: Subdiastolic cuff‐compression of the proximal calf is an easily applicable and inexpensive technique by which to reduce venous contamination of the calf station in stepping‐table MR angiography and to improve evaluation of the infrapopliteal arteries.