bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility and Compliance of Automated Measurement of Quality of Life in Oncology Practice
Authors: Wright E.P. , Selby P.J. , Crawford M. , Gillibrand A. , Johnston C. , Perren T.J. , Rush R. , Smith A. , Velikova G. , Watson K. , Gould A. , Cull A.
Published: January 2003

Purpose: Systematic quality-of-life (QOL) assessment may have value in oncology practice by increasing awareness of a wide range of issues, possibly increasing detection of psychologic morbidity, social problems, and changes in physical status, and improving care and its outcomes. However, logistic problems are substantial. Automated systems solve many of these problems. We field-tested the feasibility and compliance that can be achieved using a computer touchscreen system in two consecutive studies.

Patients and Methods: In study 1, a prospective cohort of 272 patients was offered QOL assessment at each clinic appointment for 6 months. In study 2, all patients (N = 1,291) were offered QOL assessment as part of clinic routine during a 12-week period.

Results: In study 1, 82% of patients agreed to take part, but over time, compliance was poor (median, 40%; mean, 43%) and deteriorated with longer follow-up. In study 2, the overall compliance was greatly increased (median, 100%; mean, 70%), and compliance was retained over multiple visits. In study 1, compliance was better in younger patients, males, and socially advantaged patients, but was not affected by the presence of depression or anxiety, or QOL. In the second study, building on experience in the first study, data collection and storage in the computer system was excellent, achieving 98% of collected data stored in one center. In general, patients were comfortable with the computers and the approach. Data collection on the wards was more difficult and less complete than in clinics, especially for patients undergoing acute admissions.

Conclusion: Feasibility with higher compliance was demonstrated in study 2, in which the data collection was integrated into routine care, and can be improved with further technical initiatives and education of staff.
Phase I Pharmacokinetic and Pharmacodynamic Study of Recombinant Human Endostatin in Patients With Advanced Solid Tumors
Authors: Thomas James P. , Arzoomanian Rhoda Z. , Alberti Dona , Marnocha Rebecca , Lee Fred , Friedl Andreas , Tutsch Kendra , Dresen Amy , Geiger Peter , Pluda James , Fogler William , Schiller Joan H. , Wilding George
Published: January 2003

Purpose: Endostatin is the first endogenous angiogenesis inhibitor to enter clinical trials. Laboratory investigations with endostatin have indicated broad antitumor activity coupled with remarkably low toxicity. A phase I trial of recombinant human endostatin was designed to evaluate toxicity and explore biologic effectiveness in patients with refractory solid tumors.

Patients and Methods: Endostatin was administered as a 1-hour intravenous infusion given daily for a 28-day cycle. A starting dose of 30 mg/m2 was explored with subsequent dose escalations of 60, 100, 150, 225, and 300 mg/m2. Assessment of serum pharmacokinetics was performed on all 21 patients. Western blot assay and mass spectroscopy were employed to evaluate endostatin metabolism. Circulating levels of endogenous proangiogenic growth factors were examined. Tumor and tumor blood supply were imaged by dynamic computed tomography (CT), magnetic resonance imaging, ultrasound, and positron emission tomography.

Results: Endostatin given on this schedule was essentially free of significant drug-related toxicity. Two transient episodes of grade 1 rash were observed. No clinical responses were observed. Endostatin pharmacokinetics were linear with dose, and serum concentrations were achieved that are associated with antitumor activity in preclinical models. No aggregate effect on circulating proangiogenic growth factors were seen, although several patients exhibited persistent declines in vascular endothelial growth factor levels while enrolled in the study. A few patients demonstrated changes in their dynamic CT scans suggestive of a decline in microvessel density, although overall, no consistent effect of endostatin on tumor vasculature was seen.

Conclusion: Endostatin given daily as a 1-hour intravenous infusion was well tolerated without dose-limiting toxicity at doses up to 300 mg/m2.
The effects of information on producer and consumer incentives to undertake food safety efforts: A theoretical model and policy implications
Authors: Elbasha* Elamin H. , Riggs T. Lynn
Published: January 2003

Food safety presents a double moral hazard problem. This author develops a model of food safety where consumers and producers undertake unobservable preventive measures to reduce the probability of a food‐borne illness. Losses from a food‐borne illness are shared by consumers and producers according to the existing tort law. We characterize the optimal solution and show that this risk‐sharing arrangement and imperfect information create an incentive problem where suboptimal levels of precautions by producers and consumers are attained in a noncooperative Nash equilibrium solution. We conduct comparative static analysis to trace out the effects of changes in the size of losses, the degree of orientation of the legal system, and government regulation of information provision on precautions undertaken by consumers and producers. [EconLit citations: L150, Q180.] © 2003 Wiley Periodicals, Inc. Agribusiness 19: 29–42, 2003.
Life history and the competitive environment: trajectories of growth, maturation, and reproductive output among Chacma baboons
Authors: Johnson Sara E.
Published: January 2003

The social environment is a key feature influencing primate life histories. Chacma baboons (Papio hamadryas ursinus) are a female‐bonded species with a strict linear dominance hierarchy. In this species, the allocation of energy to competing demands of growth and reproduction is hypothesized to vary as a function of competitive ability, which in turn increases with social rank. Since growth rate is a major component of life history models, measures of age‐specific growth were used to analyze variation in life history traits across social ranks. Weights of 42 immature baboons were obtained without sedation or baiting from a troop of well‐habituated chacma baboons in the Okavango Delta, Botswana. Using demographic and weight data from this wild population, five main findings emerged: 1) Weight for age and growth rate of infant and juvenile females are positively associated with maternal rank. 2) Male growth is not influenced by maternal rank. 3) Female growth shows smaller variation across feeding conditions than male growth. 4) Low‐ranking adult females continue investment in offspring through prolonged lactation until they reach a weight comparable to that of high‐ranking infants. 5) The benefit of rank to reproductive success shown in this study is 0.83 additional offspring. Reproductive span determined predominantly by age at maturation contributes 27–38% to the difference in expected number of offspring by rank, vs. 62–73% due to reproductive rate. These findings have major implications for understanding the role of social environment in phenotypic plasticity of life history traits, and in the evolution of primate life histories. Am J Phys Anthropol 120:83–98, 2003. © 2003 Wiley‐Liss, Inc.
Postmarital residence and biological variation at Pueblo Bonito
Authors: Schillaci Michael A. , Stojanowski Christopher M.
Published: January 2003

Although the social organization of many of the present‐day pueblos of the American Southwest is well‐described in the anthropological literature, many aspects of prehistoric Puebloan social organization have received limited attention since initial investigations of postmarital residence in the 1960s and 1970s. This paper examines postmarital residence at the Chaco Canyon great house of Pueblo Bonito, using biological data. Our findings are inconsistent with the previously well‐accepted hypothesis that the Pueblo II and Pueblo III occupants of the San Juan Basin conformed to a socially prescribed pattern of matrilocal residence with matrilineal descent. Univariate variance differences for nine craniometric variables indicate a pattern of increased female variability consistent with patrilocal/bilocal residence. The results of multivariate determinant ratio analyses are in agreement with the univariate results, suggesting the possibility of a patrilocal or bilocal residence preference at Pueblo Bonito. These findings are inconsistent with the notion that the female‐based system of matrilocal residence with matrilineal descent observed among the present‐day Western Pueblos was the ancestral Anasazi condition. Am J Phys Anthropol 120:1–15, 2003. © 2003 Wiley‐Liss, Inc.
Prominent expression of lysyl oxidase during mouse embryonic cardiovascular development
Authors: Tsuda Takeshi , Pan Te‐Cheng , Evangelisti Lucia , Chu Mon‐Li
Published: January 2003

By mRNA differential display in mouse hearts, lysyl oxidase (Lox), a key enzyme catalyzing cross‐links in elastin and collagens, was found to be up‐regulated between embryonic days 11 (E11) and 13 (E13). This was confirmed by semiquantitative RT‐PCR. We analyzed its spatio‐temporal expression pattern by in situ hybridization in regard to the development of myocardial cells, endocardial cushion tissue, aortic arch vessels, and epicardium. Anat Rec Part A 270A:93–96, 2003. © 2003 Wiley‐Liss, Inc.
Embryonic development of coronary vasculature in rats: Corrosion casting studies
Authors: Ratajska Anna , Ciszek Bogdan , Sowińska Agnieszka
Published: January 2003

The aim of this study was to analyze the development of coronary vessels at different stages of embryonic life in rats using corrosion casts and scanning electron microscopy (SEM). We studied morphologic details of vessel maturation, expansion, and pattern formation from the stage of development when the coronary system forms patent connections with the aorta and the right atrium (embryonic day 16 (ED16)) to full‐term fetus (ED21). The internal surface morphologies of the arterial and venous vessel walls were different and were dependent on the distance from the orifice and the capillary system. They also depended on the maturation state of a given vessel. In various branches of the coronary system we demonstrated round, fusiform or polygonal, endothelial cell imprints. The capillary network was dense, however, at the early stages of development, it formed a thin layer over the myocardium. By ED21 capillaries assumed an orientation parallel to the long axes of the cardiac myocytes. During all stages of development, different forms of angiogenesis by intussusceptive growth were observed. Splitting of the vessel wall occurred in two or three points along the vessel, forming two‐ or three‐link chains. Certain areas of vessels resembled doughnuts, from which several sister vessels originated. The coronary arteries were situated deep within the myocardial wall. The major coronary veins were mostly located on the surface of the capillary plexuses of the myocardial wall. In conclusion, this method of vessel casting enables the detection of angiogenesis by intussusceptive growth, and the visualization of a capillary's position to the myocardial wall, thickness of the capillary plexuses, and the internal surface morphology of major vessels. Anat Rec Part A 270A:109–116, 2003. © 2003 Wiley‐Liss, Inc.
Recapitulation of oral mucosal tissues in long‐term organotypic culture
Authors: Chinnathambi Sathivel , Tomanek‐Chalkley Ann , Ludwig Nicholas , King Elizabeth , DeWaard Rose , Johnson Georgia , Wertz Philip W. , Bickenbach Jackie R.
Published: January 2003

To test the influence of fibroblasts on epithelial morphology and expression of keratinocyte proteins and barrier lipids, we bioengineered homotypic and heterotypic oral mucosae and skin using cultured adult human cells. Fibroblasts were allowed to modify collagen type I gels for 2 weeks before keratinocytes were added. The organotypic cultures were then grown at the air–liquid interface for 4 weeks. In homotypic combinations, epithelial morphology and protein expression closely mimicked those in vivo. In heterotypic combinations, the morphology resembled that in vivo and keratinocytes expressed their typical markers, except when skin keratinocytes were recombined with alveolar fibroblasts; they expressed K19, K4, and K13, which is similar to oral mucosal epithelia rather than to the epidermis. Morphologically, the stratum corneum layers were typical for the epithelial tissues. Grafting the bioengineered cultures to the backs of Nude mice did not change the results, suggesting that our findings are not merely a culture phenomenon. Lipid profiles of the homotypic combinations mimicked the profiles found in the normal epithelial tissues, except that the engineered alveolar epithelium expressed more ceramide 2 than that in vivo. In the heterotypic combinations, keratinocytes appeared to control the lipid profile, except in the combination of skin keratinocytes with alveolar fibroblasts, wherein the ceramide profile appeared to be partly that of alveolar epithelium and partly that of epidermis. These results suggest that cultured adult fibroblasts and keratinocytes are sufficient to recapitulate graftable oral tissues, and, except for alveolar fibroblasts, the type of fibroblast had little influence on keratinocyte differentiation. Anat Rec Part A 270A:162–174, 2003. © 2003 Wiley‐Liss, Inc.
Growth and yield of winter wheat (Triticum aestivum L.) and corn (Zea mays L.) near a high voltage transmission line
Authors: Soja G. , Kunsch B. , Gerzabek M. , Reichenauer T. , Soja A.‐M. , Rippar G. , Bolhàr‐Nordenkampf H.R.
Published: January 2003

The objective of this study was to determine the effects of an electromagnetic field from a high voltage transmission line on the yield of agricultural crops cultivated underneath and near the transmission line. For 5 years, experiments with winter wheat and corn were carried out near the 380 kV transmission line Dürnrohr (Austria)–Slavetice (Czech Republic). Different field strengths were tested by planting the crops at different distances from the transmission line. The plants were grown in experimental plots (1.77 m2), aligned to equal electric field strengths, and were cultivated according to standard agricultural practice. The soil for all plots was homogenized layer‐specifically to a depth of 0.5 m to guarantee uniform soil conditions in the plant root environment. The soil was sampled annually for determinations of carbon content and the behavior of microbial biomass. During development of the vegetation, samples were collected at regular intervals for growth rate analyses. At physiological maturity, the plots (n = 8) were harvested for grain and straw yield determinations. The average electric and magnetic field strengths at four distances from the transmission line (nominal distances: 40, 14, 8, and 2 m) were between 0.2 and 4.0 kV/m and between 0.4 and 4.5 µT, respectively. No effect of the field exposures on soil microbial biomass could be detected. The wheat grain yields were 7% higher (average of 5 years) in the plots with the lowest field exposure than in the plots nearer to the transmission line (P < .10). The responses of the plants were more pronounced in years with drought episodes during grain filling than in humid years. No significant yield differences were found for corn yields. The extent of the yield variations attributed to the distance from the transmission line was small compared to the observed annual variations in climatic or soil specific site characteristics. Bioelectromagnetics 24:91–102, 2003. © 2003 Wiley‐Liss, Inc.
A four coil exposure system (tetracoil) producing a highly uniform magnetic field
Authors: Gottardi G. , Mesirca P. , Agostini C. , Remondini D. , Bersani F.
Published: January 2003

We propose a magnetic field exposure system (tetracoil) for in vitro and in vivo experiments, composed of two couples of circular coils satisfying a spherical constraint, whose characteristics are chosen in order to maximize the uniformity region of the magnetic field. Analytical calculations and computer simulations show that our system, as compared to the other most largely used magnetic field exposure systems, represents an optimal compromise in terms of field uniformity, accessibility for biological experiments, and ratio between overall dimension and uniformity region. Bioelectromagnetics 24:125–133, 2003. © 2003 Wiley‐Liss, Inc.
Exposure of human peripheral blood lymphocytes to electromagnetic fields associated with cellular phones leads to chromosomal instability
Authors: Mashevich Maya , Folkman Dan , Kesar Amit , Barbul Alexander , Korenstein Rafi , Jerby Eli , Avivi Lydia
Published: January 2003

Whether exposure to radiation emitted from cellular phones poses a health hazard is at the focus of current debate. We have examined whether in vitro exposure of human peripheral blood lymphocytes (PBL) to continuous 830 MHz electromagnetic fields causes losses and gains of chromosomes (aneuploidy), a major “somatic mutation” leading to genomic instability and thereby to cancer. PBL were irradiated at different average absorption rates (SAR) in the range of 1.6–8.8 W/kg for 72 hr in an exposure system based on a parallel plate resonator at temperatures ranging from 34.5–37.5 °C. The averaged SAR and its distribution in the exposed tissue culture flask were determined by combining measurements and numerical analysis based on a finite element simulation code. A linear increase in chromosome 17 aneuploidy was observed as a function of the SAR value, demonstrating that this radiation has a genotoxic effect. The SAR dependent aneuploidy was accompanied by an abnormal mode of replication of the chromosome 17 region engaged in segregation (repetitive DNA arrays associated with the centromere), suggesting that epigenetic alterations are involved in the SAR dependent genetic toxicity. Control experiments (i.e., without any RF radiation) carried out in the temperature range of 34.5–38.5 °C showed that elevated temperature is not associated with either the genetic or epigenetic alterations observed following RF radiation—the increased levels of aneuploidy and the modification in replication of the centromeric DNA arrays. These findings indicate that the genotoxic effect of the electromagnetic radiation is elicited via a non‐thermal pathway. Moreover, the fact that aneuploidy is a phenomenon known to increase the risk for cancer, should be taken into consideration in future evaluation of exposure guidelines. Bioelectromagnetics 24:82–90, 2003. © 2003 Wiley‐Liss, Inc.
Anti‐pressor effects of whole body exposure to static magnetic field on pharmacologically induced hypertension in conscious rabbits
Authors: Okano Hideyuki , Ohkubo Chiyoji
Published: January 2003

Acute effects of whole body exposure to static magnetic field (SMF) on pharmacologically induced hypertension in a conscious rabbit were evaluated. Hypertensive and vasoconstrictive actions were induced by norepinephrine (NE) or a nonselective nitric oxide synthase (NOS) inhibitor, Nω‐nitro‐l‐arginine methyl ester (l‐NAME). The hemodynamics in a central artery of the ear lobe was measured continuously and analyzed by penetrating microphotoelectric plethysmography (MPPG). Concurrently, blood pressure (BP) changes in a central artery, contralateral to that of the MPPG measured ear lobe, were monitored. Magnetic flux densities were 5.5 mT (Bmax), the magnetic gradient peaked in the throat at the level of ∼0.09 mT/mm, and the duration of exposure was 30 min. The results demonstrated that under normal physiological conditions without treatment of pharmacological agents, there were no statistically significant differences in the hemodynamics and BP changes between the sham and the SMF exposure alone. Under pharmacologically induced hypertensive conditions, the whole body exposure to nonuniform SMF with peak magnetic gradient in the carotid sinus baroreceptor significantly attenuated the vasoconstriction and suppressed the elevation of BPs. These findings suggest that antipressor effects of the SMF on the hemodynamics under NE or l‐NAME induced high vascular tone might be, in part, dependent on modulation of NE mediated response in conjunction with alteration in NOS activity, thereby modulating BPs. Bioelectromagnetics 24:139–147, 2003. © 2003 Wiley‐Liss, Inc.
Infant–mother and infant–father synchrony: The coregulation of positive arousal
Authors: Feldman Ruth
Published: January 2003

To examine the coregulation of positive affect during mother–infant and father–infant interactions, 100 couples and their first‐born child were videotaped in face‐to‐face interactions. Parents' and infant's affective states were coded in one‐second frames, and synchrony was measured with time‐series analysis. The orientation, intensity, and temporal pattern of infant positive arousal were assessed. Synchrony between same‐gender parent–infant dyads was more optimal in terms of stronger lagged associations between parent and infant affect, more frequent mutual synchrony, and shorter lags to responsiveness. Infants' arousal during mother–infant interaction cycled between medium and low levels, and high positive affect appeared gradually and was embedded within a social episode. During father–child play, positive arousal was high, sudden, and organized in multiple peaks that appeared more frequently as play progressed. Mother–infant synchrony was linked to the partners' social orientation and was inversely related to maternal depression and infant negative emotionality. Father–child synchrony was related to the intensity of positive arousal and to father attachment security. Results contribute to research on the regulation of positive emotions and describe the unique modes of affective sharing that infants coconstruct with mother and father. ©2003 Michigan Association for Infant Mental Health.
Interannual variability in the Uruguay river basin
Authors: Krepper C. M. , García N. O. , Jones P. D.
Published: January 2003

Both (El Niño–southern oscillation ENSO)‐scale and near‐decadal variations in precipitation and river flow have been noted in southeastern South America. Here we focus on the Uruguay river basin and its subcatchments. Both river flow and precipitation are analysed with singular spectrum analysis in an examination of how the signals of the subcatchments are related to the overall basin signal. The approximate 6 year signal and the 3.5 year ENSO signal are the two statistically significant peaks for the river flow. Both signals are present in all the available river flows, but only in the precipitation of the upper two‐thirds of the basin. Precipitation in the lower part of the basin shows positive trends. The ENSO signal is strongly modulated at the secular time scale; we construct a simple sinusoidal model for this modulation. Copyright © 2003 Royal Meteorological Society.
Two decades of urban climate research: a review of turbulence, exchanges of energy and water, and the urban heat island
Authors: Arnfield A. John
Published: January 2003

Progress in urban climatology over the two decades since the first publication of the International Journal of Climatology is reviewed. It is emphasized that urban climatology during this period has benefited from conceptual advances made in microclimatology and boundary‐layer climatology in general. The role of scale, heterogeneity, dynamic source areas for turbulent fluxes and the complexity introduced by the roughness sublayer over the tall, rigid roughness elements of cities is described. The diversity of urban heat islands, depending on the medium sensed and the sensing technique, is explained. The review focuses on two areas within urban climatology. First, it assesses advances in the study of selected urban climatic processes relating to urban atmospheric turbulence (including surface roughness) and exchange processes for energy and water, at scales of consideration ranging from individual facets of the urban environment, through streets and city blocks to neighbourhoods. Second, it explores the literature on the urban temperature field. The state of knowledge about urban heat islands around 1980 is described and work since then is assessed in terms of similarities to and contrasts with that situation. Finally, the main advances are summarized and recommendations for urban climate work in the future are made. Copyright © 2003 Royal Meteorological Society.
A sudden change in summer rainfall characteristics in Korea during the late 1970s
Authors: Ho Chang‐Hoi , Lee June‐Yi , Ahn Myoung‐Hwan , Lee Hee‐Sang
Published: January 2003

We have examined long‐term climate change in Korea by studying daily rainfall data over a period of 48 years (1954–2001). The results show that there is a more frequent heavy rainfall anomaly larger than 100 mm per 3 months in recent years. For further investigation, we divide the whole period into two 24 year intervals, 1954–77 and 1978–2001. Two well‐defined rainfall peaks occur during summertime in both intervals. During the earlier interval, primary and secondary rainfall peaks are found in early July and early September, respectively. In the later interval, on the other hand, the secondary peak is found in mid–late August, mainly attributed to enhanced heavy rainfall (≥30 mm day−1) events. Although a similar shift occurs in the primary peak, it is much smaller. Thus, the relatively dry spell between the two peaks becomes shorter in the later interval compared with the earlier one.

The domain‐mean geopotential height at 700 hPa (Φ700) over mid‐latitude Asia (30–50° N, 60–120° E) for the summer also experienced a sudden increase in the mid 1970s. A comparison of the spatial distribution of Φ700 between the two intervals shows large positive differences over the central‐eastern Asian continent in the later interval. In contrast to the positive anomaly of Φ700 in the later interval, there is a decreasing trend in surface temperature. The increased Φ700 introduces a stronger northerly wind over East Asia and possibly produces a moisture convergence, enhanced convective activity, and heavy rainfall over the region, in particular over Korea and central China. Copyright © 2003 Royal Meteorological Society.
Preparation and characterization of microcellular polystyrene/polystyrene ionomer blends with supercritical carbon dioxide
Authors: Wang Jin , Cheng Xingguo , Zheng Xuejing , Yuan Mingjun , He Jiasong
Published: January 2003

The preparation of microcellular polystyrene (PS), lightly sulfonated polystyrene (SPS), zinc‐neutralized lightly sulfonated polystyrene (ZnSPS), and blends of PS/SPS and PS/ZnSPS via supercritical CO2 was carried out with the pressure‐quench process. Both higher foaming temperature and lower pressure result in larger cell sizes, lower cell densities, and lower relative density for microcellular ionomers and blends as for microcellular PS. The difference among various microcellular samples is the change of cell size with the sample composition. The cell size decreases in the sequence from SPS, through PS/SPS blends, PS and PS/ZnSPS blends, to ZnSPS. The diffusivity of CO2 in samples also decreases in the sequence from SPS, through PS/SPS blends, PS and PS/ZnSPS blends, to ZnSPS. For this series of samples with similar structure and identical solubility of CO2, the varying diffusivity is responsible for the difference of cell sizes. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 368–377, 2003
Deconvolution of scanning transmission electron microscopy images of ionomers
Authors: Kirkmeyer Brian P. , Puetter Richard C. , Yahil Amos , Winey Karen I.
Published: January 2003

Previously, we studied a variety of ionomer morphologies with scanning transmission electron microscopy (STEM). Other groups have found that deconvoluting STEM images dramatically improve the overall image quality and the detection of sub‐nanometer‐scale features. In this study, STEM images of nanometer‐scale ion‐rich aggregates were deconvolved via the Pixon method with a simulated electron probe. The image models are considerably sharper with significantly decreased noise levels, thus making the size and shape of the ionic aggregates easier to distinguish relative to those in the raw STEM images. Raw and deconvoluted images of Zn‐neutralized poly(styrene‐ran‐methacrylic acid) ionomers containing spherical ionic aggregates indicate that the electron density varies smoothly from the edge to the center of the aggregates. Deconvolution also clarifies the issue of aggregate overlap in the STEM images. Furthermore, line scans across deconvoluted STEM images suggest that the three‐dimensional density distribution of these nanoaggregates compares favorably with a radially symmetric Gaussian distribution as opposed to a uniformly dense sphere. The overall result of this work is that deconvolution of STEM images provide ways in which to better investigate the morphologies of ionomers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 319–326, 2003
Resistive MHD simulations of Ganymede's magnetosphere 2. Birkeland currents and particle energetics
Authors: Ip Wing‐Huen , Kopp Andreas
Published: January 2003

The Birkeland current flows generated by Ganymede's magnetospheric interaction with the Jovian magnetosphere are simulated by using a resistive MHD code. The total field‐aligned current is estimated to be I∥ ≈ 6.6 × 105 A. The power delivered to the Jovian auroral zone and to Ganymede's polar surface via energetic charged particle bombardment is about 6 × 109 W. Ions and electrons could gain as much as 2.9–48 keV at the reconnection site of the magnetopause. The production rate of oxygen and water molecules from the associated ion sputtering effect (QII ≈ 1025 − 1026 molecules/s, QI ≈ 1–4 × 1026 molecules/s) can be derived from polar cap precipitation of the ambient Jovian energetic ions. Because Ganymede's Birkeland current system is highly time‐variable in response to the Jovian magnetic field variations, the “footpoints” of the accelerated ion beams could have rapid changes and hence the motion of the hotspots of the oxygen airglow emission as observed by the Hubble Space Telescope.
Crustal structure and relocated earthquakes in the Puget Lowland, Washington, from high‐resolution seismic tomography
Authors: Van Wagoner T. M. , Crosson R. S. , Creager K. C. , Medema G. , Preston L. , Symons N. P. , Brocher T. M.
Published: January 2003

The availability of regional earthquake data from the Pacific Northwest Seismograph Network (PNSN), together with active source data from the Seismic Hazards Investigation in Puget Sound (SHIPS) seismic experiments, has allowed us to construct a new high‐resolution 3‐D, P wave velocity model of the crust to a depth of about 30 km in the central Puget Lowland. In our method, earthquake hypocenters and velocity model are jointly coupled in a fully nonlinear tomographic inversion. Active source data constrain the upper 10–15 km of the model, and earthquakes constrain the deepest portion of the model. A number of sedimentary basins are imaged, including the previously unrecognized Muckleshoot basin, and the previously incompletely defined Possession and Sequim basins. Various features of the shallow crust are imaged in detail and their structural transitions to the mid and lower crust are revealed. These include the Tacoma basin and fault zone, the Seattle basin and fault zone, the Seattle and Port Ludlow velocity highs, the Port Townsend basin, the Kingston Arch, and the Crescent basement, which is arched beneath the Lowland from its surface exposure in the eastern Olympics. Strong lateral velocity gradients, consistent with the existence of previously inferred faults, are observed, bounding the southern Port Townsend basin, the western edge of the Seattle basin beneath Dabob Bay, and portions of the Port Ludlow velocity high and the Tacoma basin. Significant velocity gradients are not observed across the southern Whidbey Island fault, the Lofall fault, or along most of the inferred location of the Hood Canal fault. Using improved earthquake locations resulting from our inversion, we determined focal mechanisms for a number of the best recorded earthquakes in the data set, revealing a complex pattern of deformation dominated by general arc‐parallel regional tectonic compression. Most earthquakes occur in the basement rocks inferred to be the lower Tertiary Crescent formation. The sedimentary basins and the eastern part of the Olympic subduction complex are largely devoid of earthquakes. Clear association of hypocenters and focal mechanisms with previously mapped or proposed faults is difficult; however, seismicity, structure, and focal mechanisms associated with the Seattle fault zone suggest a possible high‐angle mode of deformation with the north side up. We suggest that this deformation may be driven by isostatic readjustment of the Seattle basin.
Influence of Okhotsk Sea Intermediate Water on the Oyashio and North Pacific Intermediate Water
Authors: Yasuda Ichiro , Kouketsu Shinya , Katsumata Katsurou , Ohiwa Mitchihiro , Kawasaki Yasuhiro , Kusaka Akira
Published: January 2003

The volume transport between the Okhotsk Sea and western subarctic North Pacific is estimated on the basis of direct current measurements made by a lowered acoustic Doppler current profiler (LADCP) and hydrographic data taken in August and September 1999 near the Kuril Islands. The estimated southwestward Oyashio transport was 11–12 Sv (=106 m3/s) in the density range of 26.7–27.4 σθ. The net transport of the Okhotsk Sea water (OSW) was 3.4 Sv, of which 1.3 Sv was coming out through the Kruzenshterna Strait and 2.1 Sv was coming out through the Bussol' Strait. A bidirectional flow was observed in the Bussol' Strait: inflow in the northern part of the strait and outflow in the southern part; 0.6 Sv of OSW recirculated along the western subarctic gyre. The remaining 2.8 Sv of OSW could contribute to the formation of North Pacific Intermediate Water as a cross‐Subarctic Front transport along the coast (1.4 Sv) and across the offshore SAF (1.4 Sv). The production rate of the Dense Shelf Water (DSW) through sea ice formation was estimated to be at least 1.1 Sv. When the intermediate OSW is formed through the mixing between cold and fresh DSW and warm and salty waters from the Pacific and Japan Sea, 16.8 TW (=1012 W) of heat, 0.007 Sv of freshwater, and 2.3 × 105 kg/s of salt are exchanged. The net flux of oxygen and anthropogenic CO2 (ex‐CO2) from the Okhotsk Sea into the Pacific in 26.7–27.4 σθ is estimated to be 10.5 and 2.1 Tmol/yr (0.025 GtC/yr), respectively. The ex‐CO2 transported by OSW accounts for about 10% of the accumulation of ex‐CO2 in the subarctic and subtropical Pacific.
Evolution of 1996–1999 La Niña and El Niño conditions off the western coast of South America: A remote sensing perspective
Authors: Carr Mary‐Elena , Strub P. Ted , Thomas Andrew C. , Blanco Jose Luis
Published: January 2003

We present the evolution of oceanographic conditions off the western coast of South America between 1996 and 1999, including the cold periods of 1996 and 1998–1999 and the 1997–1998 El Niño, using satellite observations of sea level, winds, sea surface temperature (SST), and chlorophyll concentration. Following a period of cold SST and low sea levels in 1996, both were anomalously high between March 1997 and May 1998. The anomalies were greatest between 5°S and 15°S, although they extended beyond 40°S. Two distinct peaks in sea level and SST occurred in June–July 1997 and December 1997 to January 1998, separated by a relaxation period (August–November) of weaker anomalies. Satellite winds were upwelling favorable throughout the time period for most of the region and in fact increased between November 1997 and March 1998 between 5°S and 25°S. Satellite‐derived chlorophyll concentrations are available for November 1996 to June 1997 (Ocean Color and Temperature Sensor (OCTS)) and then from October 1997 to present (Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS)). Near‐surface chlorophyll concentrations fell from May to June 1997 and from December 1997 to March 1998. The decrease was more pronounced in northern Chile than off the coast of Peru or central Chile and was stronger for larger cross‐shelf averaging bins since nearshore concentrations remained relatively high.
A model study of the connection between polar and midlatitude ozone loss in the Northern Hemisphere lower stratosphere
Authors: Millard G. A. , Lee A. M. , Pyle J. A.
Published: January 2003

A numerical model has been used to quantify halogen‐induced ozone loss at the winter pole and at middle latitudes. This loss is compared with that due to nonhalogen ozone‐destroying cycles. The three‐dimensional off‐line chemical transport model, SLIMCAT, was run at 3.75° latitude by 3.75° longitude, with United Kingdom Meteorological Office analyzed winds and temperatures. The contribution of polar processes to ozone loss at middle latitudes was investigated with novel tracers mapped to equivalent latitudes. Novel tracers were also included in SLIMCAT to follow ozone loss by reactions with ClOx, BrOx, NOx, and HOx, and to follow ozone production by oxygen photolysis. The interannual variability of the different processes was studied for five winters in the 1990s, which covered a variety of meteorological conditions in and around the polar vortex. Analysis of the ozone loss tracers shows large interannual variability in the relative strengths of particular chemical ozone loss mechanisms depending on the meteorology of the given year. In all cases, the ClO‐BrO cycle dominates at polar latitudes. The role of mixing between the pole and middle latitudes also varies with the meteorological conditions. In winters with a cold, stable vortex, like 1996/1997, there is little impact of polar processes on midlatitude loss. In contrast, the cold, disturbed vortex of 1999/2000 contributed significantly to the ozone loss in middle latitudes. In all winters, ozone loss from cycles involving halogens was an important contributor (40–70%) to the modeled midlatitude ozone loss.
Numerical prediction of northeast Asian dust storms using an integrated wind erosion modeling system
Authors: Shao Yaping , Jung Eunjoo , Leslie Lance M.
Published: January 2003

Northeast Asia is one of the most active regions of mineral dust emission. In this study, an integrated wind erosion modeling system is developed, which consists of an atmospheric model, a land surface scheme, a wind erosion scheme (for dust emission and sediment drift), a dust transport and deposition scheme, and a geographic information database. The integrated system is applied to the prediction of northeast Asian dust storms, from the perspective of dust emission and dust concentration of various particle size groups. Two successive but different dust storm events that occurred on 6–7 and 9–10 April 2000 are studied and the predictions are compared qualitatively with meteorological and satellite observations. The comparison shows that the integrated system simulated well the spatial and temporal evolution of dust source and dust concentration. The simulations reveal several significant synoptic features of dust storms. It is found that during a typical dust storm episode, the total emission of dust (with d ≤ 22 μm, d is particle diameter) in northeast Asia amounts to 4.62 Mt/day, including 0.04, 1.88, and 2.70 Mt/day for particle size groups, d ≤ 2 μm, 2 < d ≤ 11 μm, and 11 < d ≤ 22 μm, respectively.
Simulations of aerosol‐cloud‐dynamical feedbacks resulting from entrainment of aerosol into the marine boundary layer during the Atlantic Stratocumulus Transition Experiment
Authors: Jiang Hongli , Feingold Graham , Cotton William R.
Published: January 2003

Numerical simulations of a cloudy marine boundary layer (MBL) observed during the Atlantic Stratocumulus Transition Experiment were performed to study the influence of entrainment of free tropospheric cloud condensation nuclei (CCN) on cloud microphysics, dynamics, and radiative properties. The initial CCN concentration is 100 cm−3 in one simulation, while in the second simulation it varies from 100 cm−3 below the cloud top to a peak of 1200 cm−3 at the inversion. In the clean case, cooling from evaporating drizzle destabilizes the layer just below cloud base (not the entire subcloud layer) with respect to the surface, and promotes stronger penetrating cumulus. In the case with the elevated pollution layer, reduced drizzle at the cloud base results in weaker penetrating cumulus and a less effective supply of surface moisture to the cloud. This results in a much lower liquid water path (LWP) relative to the clean case that offsets the cloud albedo enhancement due to higher drop concentrations. Thus, although entrained CCN enhance the droplet concentration, the net effect on the cloud albedo is small. Additional simulations were performed to study the sensitivity of the MBL to varying levels of large‐scale subsidence. The change in large‐scale subsidence has a large effect on boundary layer dynamics, cloud microphysics, and the radiative budget. The simulations are used to separate the effects of enhanced albedo due to enhanced drop concentrations at constant LWP and those where LWP is modified due to dynamical feedbacks. For this case study, weaker subsidence results in a cloud with higher LWP and a cloud albedo that is enhanced over and above that due to enhanced droplet concentration. The simulations point to the complex dynamical‐microphysical‐radiative feedbacks in the MBL and how elevated polluted layers can change cloud radiative forcing in ways that would not be easily predicted by large‐scale models.
Detection of a buried wire with two resistively loaded wire antennas
Authors: Vossen Stefan H. J. A. , Tijhuis Anton G. , Lepelaars Eugène S. A. M. , Zwamborn A. Peter M.
Published: January 2003

The use of two identical straight thin‐wire antennas for the detection of a buried wire is analyzed with the aid of numerical calculations. The buried wire is located below an interface between two homogeneous half‐spaces. The detection setup, which is formed by a transmitting and a receiving wire, is located above the interface. The transmitter is excited by a pulsed voltage in a small gap. A resistance profile according to Wu and King [1965] has been used to suppress the reflections at the end of the wires. This enhances the visibility of properties of the lower half‐space directly from the time response of the current along the receiving antenna. The problem is solved in several steps. First, the electric field integral equation for the total current along a single thin‐wire antenna in a homogeneous space is formulated. The result is then used to construct a set of coupled integral equations to describe the currents along all three wires without the resistive load. The integral equations contain the transmitted and reflected fields due to the interface. Next, the set of integral equations is adapted for the resistance profile along the wires of the detection setup. The reflected and transmitted fields in both half‐spaces are treated as secondary incident fields in the integral equation for the currents along the wires. In these equations, the response from a pulsed dipole source in the same configuration occurs as a Green's function. The inverse spatial Fourier transformation that occurs in the transmitted and reflected fields is carried out with the aid of a frequency independent, composite Gaussian quadrature rule. The set of coupled integral equations is solved by using the continuous‐time discretized‐space approach, where the space discretization is kept fixed for all frequencies. This results in a linear system of equations with a fixed dimension which is solved by the conjugate gradient‐fast Fourier transform (CG‐FFT) method. With the aid of a marching‐on‐in‐frequency scheme, the system is solved for a number of frequencies. Time domain results are obtained by applying an inverse Fourier transformation. Representative numerical results are presented and discussed.
Local lithospheric relief associated with fracture zones and ponded plume material
Authors: Sleep Norman H.
Published: January 2003

Buoyant plume material ponds at the base of oceanic lithosphere. It is a natural probe for the relief on the base of the lithosphere owing to plate age because it flows laterally along an upside‐down drainage pattern. Geomorphic and geochemical studies of near‐ridge and on‐ridge hot spots indicate, as expected, that the oceanic lithosphere thickens as it ages. Corridors of thin lithosphere channel plume material along the axis, while the thick lithosphere at the end of ridge segments dams this along‐axis flow. Channel hot spots extend from plumes toward ridge axes. However, a good correlation between local lithospheric thickness and local age is not evident at fracture zones within the old ocean basins. Such a correlation would be expected if the lithosphere cooled only by conduction. Then pressure‐release melting and volcanoes would occur preferentially near fracture zones where plume material cascades from thick old to thin young lithosphere. This concentration of volcanic edifices does not occur. This lack of correlation between lithosphere thickness and plate age is an expected consequence of small‐scale convection at the base of the lithosphere. Scaling relationships and numerical models indicate that modestly vigorous convection of several milliwatt per meter squared is sufficient to perturb local lithospheric relief beneath fracture zones without changing the gross correlation of lithospheric thickness with plate age. Typically, the step in lithospheric thickness moves toward the old side of the fracture zone.
Proton‐cyclotron instability induced by the thermal anisotropy of minor ions
Authors: Gomberoff L. , Valdivia J. A.
Published: January 2003

We study ion cyclotron instabilities due to the thermal anisotropy of minor heavy ions. Very large thermal anisotropies have been observed in O+5 ions in coronal holes [Cranmer, 2001], and as is well known, the thermal anisotropy of an ion species is the free‐energy source of ion cyclotron waves of the corresponding species. Nevertheless, as the heavy ion thermal anisotropy in coronal holes develops, the ions are being heated and accelerated, and therefore they acquire a drift velocity relative to the protons. Owing to the drift velocity a new instability branch develops very close to the proton gyrofrequency. In other words, heavy ion cyclotron waves can also trigger proton‐cyclotron waves as a result of the drift velocity of the minor heavy ions. We propose that the proton‐cyclotron waves generated by this mechanism are absorbed by the protons, and therefore this process can contribute to fast proton heating in coronal holes.
Dust‐acoustic‐drift wave instability in a space dusty plasma
Authors: Rosenberg M. , Shukla P. K.
Published: January 2003

A dust‐acoustic‐drift wave instability is investigated in a nonuniform collisional dusty magnetoplasma. The plasma parameters are such that the electrons are magnetized, while the ions and dust grains are collisional and nonmagnetized, which may be characteristics of dusty plasmas in the E region of the Earth's ionosphere. The instability is driven by electron E × B and diamagnetic drifts. Possible application to the edges of dusty meteor trails at altitudes >95 km is considered. It is shown that this instability could be driven by an electron cross‐field drift smaller than the ion thermal speed in a meteor trail containing a sufficient charge density of positively charged dust.