bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary experience with arterial chemoembolization for hepatoblastoma and hepatocellular carcinoma in children
Authors: Czauderna Piotr , Zbrzezniak Grzegorz , Narozanski Wojciech , Korzon Maria , Wyszomirska Maria , Stoba Czeslaw
Published: August 2005

The objective of this work was to test feasibility and efficacy of hepatic artery chemoembolization (HACE) in unresectable malignant liver tumors. Five patients aged from 1–12 years were treated in the Medical University of Gdansk from 1999 to 2002. All had locally advanced tumors, which did not respond to systemic chemotherapy: four, hepatoblastoma (HB) and one, hepatocellular carcinoma (HCC). Arteriography was performed and chemoembolization suspension (cisplatin + doxorubicin + mitomycin mixed with lipiodol) was injected, followed by gelatin foam particles. The procedure was performed one to three times in each patient. In four patients (three, HB, one, fibrolamellar HCC), tumor response was observed, with decrease in the diameter of the mass of 25–33% and fall in the AFP level of 83–99%. One child with HB was non‐evaluable due to early death caused by systemic myelotoxicity. Two patients (2 HB) underwent macroscopically complete tumor resection, 1 is alive and well, and 1 died at the end of surgery for an unknown reason (possibly related to cardiotoxicity of earlier systemic chemotherapy). One HB patient was successfully transplanted after two HACE courses. The only HCC patient died because of pulmonary oil embolism immediately after the third HACE course. HACE can lead to tumor regression in most cases and may be considered an alternative for patients with unresectable liver tumors who do not respond to primary systemic chemotherapy and are not candidates for liver transplantation for various reasons. © 2005 Wiley‐Liss, Inc.
Liver involvement in neuroblastoma: The memorial Sloan‐Kettering experience supports treatment reduction in young patients
Authors: Kushner Brian H. , Kramer Kim , LaQuaglia Michael P. , Modak Shakeel , Cheung Nai‐Kong V.
Published: August 2005

Background

We reviewed clinical and biologic findings in a series of infants with neuroblastoma (NB) in liver. The aim was to gain insights into improving therapy.

Patients and Methods

Among 19 newly or recently diagnosed infants with NB in liver, 1987–2002, those with stage 4 involving bone received chemotherapy, while those without bone or extensive bone marrow (BM) involvement were observed or received limited treatment if NB caused life‐threatening symptoms. We assessed results in the context of NB treatment risk stratification, which is based on age, stage, and selected biologic features (MYCN, ploidy, histology).

Results

Six of eight infants with bone involvement became long‐term event‐free survivors including 1/2 with MYCN amplification and four who received only 4–6 cycles of chemotherapy; at the end of treatment, four infants had abnormalities in liver ± the primary site, but these resolved. All 11 infants without bone lesions became long‐term survivors with either no cytotoxic therapy or only one cycle of chemotherapy (± radiotherapy to liver), including four who had stage 4 and one stage 4S patient who still had NB in BM at age 15 months.

Conclusions

Treatment reduction should be considered for subsets of infants with non‐MYCN‐amplified widespread NB: stage 4 without bone or extensive BM involvement may not require cytotoxic therapy, stage 4S with symptomatic hepatomegaly may not require multiple cycles of chemotherapy, and classic stage 4 may do well with limited chemotherapy. Persistent liver abnormalities post‐treatment may not require continued therapy to achieve a radiologic complete remission. © 2005 Wiley‐Liss, Inc.
Pediatric surface osteosarcoma: Clinical, pathologic, and radiologic features
Authors: Kaste Sue C. , Fuller Christine E. , Saharia Ashish , Neel Michael D. , Rao Bhaskar N. , Daw Najat C.
Published: August 2005

Background

Osteosarcoma (OS) arising from the surface of bone is far less common than its intramedullary counterpart. Although surface OSs share some radiographic and clinical features, they can be divided into three distinct histologic subtypes.

Procedure

We reviewed the clinical, radiographic, and pathologic features of 14 cases of pediatric surface OS treated at St. Jude Children's Research Hospital between 1970 and 2003.

Results

Seven patients had parosteal, five had periosteal, and two had high‐grade surface OS. The median age at diagnosis was 16.2 years (range, 13.6–18.5 years). Nine patients were male; 11 were Caucasian. None had metastatic disease at diagnosis. Primary tumor sites included distal femur (n = 6), mid to proximal femur (n = 4), and mid to proximal tibia (n = 4). All 14 patients were treated with surgery, and 7 (1 with parosteal, 4 with periosteal, 2 with high‐grade tumors) received chemotherapy. One patient experienced pulmonary metastasis of periosteal OS 16 months and 43 months after diagnosis; long‐term disease‐free survival followed resection of the metastatic tumors. Twelve patients remained alive and disease‐free a median of 10 years (range, 1.5–25.4 years) after diagnosis. One patient died of high‐grade surface OS 1.8 years after diagnosis, and one patient with periosteal OS died of gastric cancer 18.2 years after diagnosis of OS.

Conclusions

The histologic grade predicts the clinical behavior of pediatric surface OS. Complete resection is the treatment of choice regardless of tumor subtype. Whereas chemotherapy is not indicated for parosteal OS, its role in periosteal OS remains controversial. © 2005 Wiley‐Liss, Inc.
Estimating the attitude of immigrants toward primary prevention of the hemoglobinopathies
Authors: Giordano Piero C. , Dihal Ashwin A. , Harteveld Cornelis L.
Published: August 2005

Objectives

We conducted population specific confidential enquiries among immigrants who had never experienced hemoglobinopathies, to study the reliability of this approach in estimating the wish for primary prevention by prenatal diagnosis and selective abortion.

Methods

We collected data from Surinamese Hindustanis (n = 119), Surinamese and Antillean Afro‐Americans (n = 105) and North Africans (mainly Moroccans) (n = 102), living in Holland. We also interviewed 105 informed individuals of different ethnicities, all members of the multi‐ethnic patients and carriers' organization ‘OSCAR Nederland’.

Results

On average, 68% of the Surinamese Hindustanis and 42% of the Surinamese Afro‐Americans were in favor of selective abortion in case of affected pregnancy. Remarkably, 77% of the last group wanted to be tested for carrier diagnostics and 67% declared to have knowledge of the disease before they were informed. Only 16% of the Moroccans were in favor of selective abortion in case of an affected fetus, while 79% wanted to have blood analysis to establish their carrier status.

Conclusions

The apparently limited wish for selective abortion expressed by Moroccans is in contrast with the high number of illegal abortions reported among married women in Morocco (39%). The wish for selective abortion among informed members of the patients' organization was more than 80%. Copyright © 2005 John Wiley & Sons, Ltd.
Poly(styrene‐co‐glycerol dimethacrylate): Synthesis, characterization, and application as a resin for gel‐phase peptide synthesis
Authors: Roice Michael , Pillai V. N. Rajasekharan
Published: August 2005

An efficient cross‐linked polymer support for solid‐phase synthesis was prepared by introducing glycerol dimethacrylate cross‐linker to polystyrene network using free radical aqueous suspension polymerization. The support was characterized by various spectroscopic methods. Morphological feature of the resin was analyzed by microscopy. The polymerization reaction was investigated with respect to the effect of amount of cross‐linking agent, which in turn vary the swelling, loading, and the mechanical stability of the resin. The solvent uptake of the polymer was studied in relation to cross‐linking and compared with Merrifield resin. The stability of the resin was tested in different synthetic conditions used for solid‐phase peptide synthesis. Hydroxy group of the support was derivatized to chloro and then amino groups using different reagents and reaction conditions. Efficiency of the support was tested and compared with TentaGel™ resin by following different steps involved in the synthesis of the 65–74 fragment of acyl carrier protein. The results showed that the poly(styrene‐co‐glycerol dimethacrylate) (GDMA‐PS) is equally efficient as TentaGel resin in peptide synthesis. The purity of the peptides was analyzed by HPLC and identities were determined by mass spectroscopy and amino acid analysis. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4382–4392, 2005
Surface characterization and properties of plasma‐modified cyclic olefin copolymer/layered silicate nanocomposites
Authors: Wu Tzong‐Ming , Wu Chine‐Wen
Published: August 2005

In this study, cyclic olefin copolymer (COC)/layered silicate nanocomposites (CLSNs) were prepared by the intercalation of COC polymer into organically‐modified layered silicate through the solution mixing process. Both X‐ray diffraction data and transmission electron microscopy images of CLSNs indicate most of the swellable silicate layers were disorderedly intercalated into the COC matrix. The effect of layered silicate on the mechanical and barrier properties of the fabricated nanocomposites shows significant improvements in the storage modulus and water permeability when compared with that of neat COC matrix. Surfaces of COC and CLSN films were modified by a mixture of oxygen (O2) and nitrogen (N2) plasmas with various treated times, system pressures, and radio frequency (RF) powers. The surfaces of plasma‐modified COC and CLSN were investigated using scanning probe microscopy and contact‐angle measurements. The exposure of the COC and CLSN film to the plasmas led to the combination of etching reactions of polymer surface initiated by plasma and the following addition reactions of new functional groups onto polymer surfaces to change the topology of COC film surfaces. The surface roughness was closely related to how high and how long the RF power was input into the system. The plasmas also led to changes in the surface properties of the CLSN surfaces from hydrophobic to hydrophilic; and the contact angle of water on the surface decreases. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2745–2753, 2005
Geomorphological, hydrological and climatic significance of rock glaciers in the Andes of Central Chile (33–35°S)
Authors: Brenning Alexander
Published: August 2005

Rock glaciers in the Andes of Santiago de Chile occupy c. 10% of the total land surface between 3500 and 4250 m ASL. An estimated water equivalent of 0.3 km3 per 1000 km2 of mountain area is stored within them; this value is one order of magnitude higher than in the Swiss Alps. Climate data indicate that the lowest occurrences of active rock glaciers in the Andes of Santiago are not in equilibrium with modern climate. Relict features are found as low as at 2630 m ASL, implying a depression of the mean annual air temperature of at least c. 5.5°C. South of Santiago, active rock glacier distribution ends at 35° 15′S due to lower topography, young volcanism and increased humidity. Copyright © 2005 John Wiley & Sons, Ltd.
Quantifying permafrost patterns using Minkowski densities
Authors: Roth Kurt , Boike Julia , Vogel Hans‐Jörg
Published: August 2005

Minkowski densities and density functions are measures for quantifying arbitrary binary patterns. They are employed here to describe permafrost patterns obtained from aerial photographs. We demonstrate that images taken at two neighbouring sites shown distinctly different patterns and quantify the difference. It is found that one of the sites exhibits an essentially single‐scale structure while the other one has a multiscale organization. Minkowski densities and density functions are thus proposed as sensitive and objective measures to quantify the change of permafrost patterns in space or in time. Copyright © 2005 John Wiley & Sons, Ltd.
Near‐surface ground ice in sediments of the Mackenzie Delta, Northwest Territories, Canada
Authors: Kokelj S. V. , Burn C. R.
Published: August 2005

The ice content of near‐surface permafrost was determined at more than 70 sites in the Mackenzie Delta, Northwest Territories. Willow and alder communities growing on aggrading surfaces with well‐drained sandy silts and ‘warm’ ground temperatures were underlain by permafrost with low ice content. Spruce forests above the level of annual flooding, lakeside alder communities in the central and southern delta, and sedge wetlands in the northern delta with moist silty loam soils, low sedimentation rates and ‘cold’ ground temperatures were underlain by medium to high ice‐content permafrost. Beneath spruce forests, a layer of near‐surface ice accumulation 1 to 2 m thick was underlain by alluvium bonded by pore ice. These profiles indicate that contemporary conditions favour near‐surface ice accumulation. The preservation of ice‐poor permafrost at depth demonstrates the limited vertical accumulation of near‐surface segregated ice. In contrast, at lakeshore alder or sedge wetlands, segregated ice extended at least 2 m below the base of the active layer, indicating that permafrost aggraded in a saturated environment. Development of ground ice in the Mackenzie Delta may elevate alluvial surfaces, modify the flooding regime, and thereby influence soil conditions and ecological succession. Copyright © 2005 John Wiley & Sons, Ltd.
Light scattering by dislocations in group‐III nitrides
Authors: Rebane Y. T. , Gorbunov R. I. , Shreter Y. G.
Published: August 2005

Light scattering by dislocations in group‐III nitrides has been studied. The effects of dislocation strain field and hollow cores on light scattering have been investigated. It is found that the coreless edge dislocation and the edge dislocations with hollow cores both participate in light scattering. Screw dislocations contribute to light scattering only if they have hollow cores. Analytical expressions for differential cross sections of light scattering by edge and screw dislocations have been obtained. Transport cross sections for in‐plane and transversal light polarizations have been calculated. Calculated spectral dependencies of the scattering cross sections show significant resonant enhancement of the light scattering in the vicinity of the absorption edge. An angle diffusion coefficient of light beam directions has been obtained that can be used for experimental determination of density, Burgers vectors and core radii of threading dislocations in III‐nitride crystals by optical means. In crystal films with high dislocation density the exponential decay of laterally propagating light rays resulting from scattering by dislocations can exceed the decay related to light absorption. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanoprocesses in polymer‐derived Si–O–C ceramics: Electronmicroscopic observations and reaction kinetics
Authors: Berger A. , Pippel E. , Woltersdorf J. , Scheffler M. , Cromme P. , Greil P.
Published: August 2005

Nickel acetate doped poly(methylphenylsilsesquioxane) with and without silicon filler loading was pyrolysed in argon atmosphere between 800 and 1500 °C. The ceramic residues were investigated with specific view of the nanoaggregates formed in pores during the polymer‐to‐ceramic conversion. After pyrolysis at 900 °C carbon nanotubes as well as nanowires with a crystalline SiC core and an amorphous SiO2 shell were found in Si filler‐free and Si filler‐loaded samples, respectively. The evolution of the microstructure and the composition of these carbon nanotubes and SiC/SiO2 nanowires were studied by HREM, SEM, EELS, EFTEM and evolved gas analysis. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Liquid‐Ga‐Filled Carbon Nanotube: A Miniaturized Temperature Sensor and Electrical Switch
Authors: Dorozhkin Pavel S. , Tovstonog Sergey V. , Golberg Dmitri , Zhan Jinhua , Ishikawa Yiji , Shiozawa Masahiro , Nakanishi Haruyuki , Nakata Keiichi , Bando Yoshio
Published: August 2005

Temperature control on the nanometer scale is a challenging task in many physical, chemical, and material science applications where small experimental volumes with high temperature gradients are used. The crucial difficulty is reducing the size of temperature sensors while keeping their sensitivity, working temperature range, and, most importantly, their simplicity and accuracy of temperature reading. In this work, we demonstrate the ultimate miniaturization of the classic thermometer using an expanding column of liquid gallium inside a multi‐walled C nanotube for precise temperature measurements. We report that electrical conductivity through unfilled nanotube regions is diffusive with a resistance per unit length of ≈10 kΩ μm−1, whereas Ga‐filled segments of the nanotube show metallic behavior with a low resistance of ≈100 Ω μm−1. No noticeable Schottky barrier exists between the nanotube carbon shell and the inner Ga filling. Based on these findings, an individual carbon nanotube partially filled with liquid Ga is used as a temperature sensor and/or switch. The nanotube’s electrical resistance decreases linearly with increasing temperature as the metallic Ga column expands inside the tube channel. In addition, the tube resistance drops sharply when two encapsulated Ga columns approaching each other meet inside the nanotube, producing a switching action that can occur at any predetermined temperature, as the Ga column position inside the nanotube can be effectively pre‐adjusted by nanoindentation using an atomic force microscope.
Prevalence of Major Life Events among Patients and Community Dwellers
Authors: Peterson Margaret G. E. , Allegrante John P. , MacKenzie C. Ronald , Helfet David , Paget Stephen A. , Pangas Marjorie
Published: August 2005

Background

Life events have been shown to be associated with health and illness.

Methods

We studied the number of life events experienced by hip fracture patients, nonfracture rheumatology patients, and community-dwelling asymptomatic residents in the year before interview. Fifty-four hip fracture patients, 63 ambulatory patients, and 115 community-dwelling residents participated in the study. All were older than 65 years. Descriptive statistics and nonparametric analyses were performed.

Results

The number of events reported in the previous 12months was higher for hipfracture patients than for community participants ( p = 0.02). At least one bereavement was reported by 32% of hipfracture patients, 27% of ambulatory patients, and 26% of community dwellers ( p = 0.8). Ten percent of all respondents reported experiencing more than one bereavement.

Conclusion

This has important consequences when considering the care of these patients and the mental distress they may be experiencing, especially in the aftermath of local disasters or trauma. Medications may not always be the best treatment, and better psychosocial assessments and delivery systems are needed.
Effective maintenance treatment—breaking the cycle of bipolar disorder
Authors: Goodwin Guy , Vieta Eduard
Published: August 2005

Clinical guidelines for treatment and research of bipolar disorder greatly benefit from the synthesis of data from individual studies. The British Association for Psychopharmacology bases its guidelines on evidence from opinions (level D) to systematic reviews of primary trial data (level A). The report details conclusions of its 1-day consensus meeting to develop guidelines covering diagnosis, clinical management, pharmacotherapy for acute episodes, relapse prevention and treatment discontinuation. Monotherapy for long-term management is preferred, having reduced side-effects and drug interactions and improved compliance. Combination therapy is often preferred for acute episodes, using antipsychotics for mania or antidepressants for depression. Increased efficacy may be attributed to multiple mechanisms of action and potentially lower doses. In clinical practice, maintenance monotherapy has limited success for chronic episodes and polypharmacy is frequently used, though the best combination remains unclear. A new collaborative approach based on simple clinical trials is required to change current medical practice.
Comparison of phosphatidylinositol‐3‐kinase signalling within a panel of human colorectal cancer cell lines with mutant or wild‐type PIK3CA
Authors: Morrow Christopher J. , Gray Alexander , Dive Caroline
Published: August 2005

Recent studies have identified conserved missense mutations in PIK3CA, the gene encoding the catalytic phosphatidylinositol‐3‐kinase subunit p110α, in a variety of human cancers. Further investigation demonstrated that PIK3CA mutations lead to increased basal phosphatidylinositol‐3‐kinase activity, promoting cell growth and invasion [Samuels, Y., Diaz, L.A., Jr., Schmidt‐Kittler, O., Cummins, J.M., Delong, L., Cheong, I., Rago, C., Huso, D.L., Lengauer, C., Kinzler, K.W., Vogelstein, B. and Velculescu, V.E. (2005) Mutant PIK3CA promotes cell growth and invasion of human cancer cells. Cancer Cell 7, 561–573]. A panel of commonly used colorectal cancer cell lines was screened for these PIK3CA mutations. Constitutive and IGF‐1‐stimulated phosphatidylinositol‐3‐kinase activity, signal response and duration were assessed. In the assays used no differences distinguished cells carrying PIK3CA mutations indicating that these mutations did not significantly alter growth factor stimulated or steady state phosphatidylinositol‐3‐kinase activity in normal cell culture conditions.
Effect of the increased stability of the penicillin amidase mRNA on the protein expression levels
Authors: Viegas Sandra C. , Schmidt Dorothea , Kasche Volker , Arraiano Cecília M. , Ignatova Zoya
Published: August 2005

Several factors at transcriptional, post‐transcriptional or post‐translational level determine the fate of a target protein and can severely restrict its yield. Here, we focus on the post‐transcriptional regulation of the biosynthesis of the periplasmic protein, penicillin amidase (PA). The PA mRNA stability was determined under depleted RNase conditions in strains carrying single or multiple RNase deletions. Single deletion of the endonuclease RNase E yielded, as the highest, a fourfold stabilization of the PA mRNA. This effect, however, was reduced twice at post‐translational level. The RNase II, generating secondary exonucleolytic cleavages in the mRNA, although not significantly influencing the PA mRNA decay, led also to an increase of the amount of mature PA. The non‐proportional correlation between increased mRNA longevity and amount of active enzyme propose that the rational strategies for yield improvement must be based on a simultaneous tuning of more than one yield restricting factor.
Fluoxetine (Prozac) interaction with the mitochondrial voltage‐dependent anion channel and protection against apoptotic cell death
Authors: Nahon Edna , Israelson Adrian , Abu-Hamad Salah , Shoshan-Barmatz Varda
Published: August 2005

Here, we demonstrate that fluoxetine interacted with VDAC and decreased its conductance. Fluoxetine inhibited the opening of the mitochondrial permeability transition pore, the release of cytochrome c, and protected against staurosporine‐induced apoptotic cell death. These findings may explain some of the reported fluoxetine side effects.
Reduced risk of Alzheimer's disease with high folate intake: The Baltimore Longitudinal Study of Aging
Authors: Corrada María M. , Kawas Claudia H. , Hallfrisch Judith , Muller Denis , Brookmeyer Ron
Published: August 2005

Background

Study findings have suggested an association between Alzheimer's disease (AD) risk and several vitamins and have speculated about their use as preventive agents. Here, we examine whether total intake (intake from diet plus supplements) of antioxidant vitamins (E, C, carotenoids) and B vitamins (folate, B6, and B12) is associated with a reduced risk of AD.

Methods

Participants were 579 nondemented elderly volunteers from the Baltimore Longitudinal Study of Aging who completed dietary diaries and recorded supplement intake for a 7‐day period. Cox regression was used to estimate the relative risk (RR) of AD associated with total vitamin intake categorized into levels above or below the Recommended Dietary Allowance (RDA).

Results

After a mean follow‐up of 9.3 years, AD developed in 57 participants. Higher intake of folate (RR, 0.41; 95% confidence interval [CI], 0.22 to 0.76), vitamin E (RR, 0.56; 95% CI, 0.30 to 1.06), and vitamin B6(RR, 0.41; 95% CI, 0.20 to 0.84) were associated individually with a decreased risk of AD after adjusting for age, gender, education, and caloric intake. When these 3 vitamins were analyzed together, only total intake of folate at or above the RDA (RR, 0.45; 95% CI, 0.21 to 0.97) was associated with a significant decreased risk of AD. No association was found between total intake of vitamins C, carotenoids, or vitamin B12and risk of AD.

Conclusions

These findings suggest that total intake of folate at or above the RDA is associated with a reduced risk of AD. Additional studies are necessary to further investigate whether folate or other(s) unmeasured factor(s) may be responsible for this reduction in risk.
The rise of the Russian business elite
Authors: Kryshtanovskaya Olga , White Stephen
Published: August 2005

The early 1990s saw the formation of a new group of Russian property owners, often derivative of the late Soviet nomenklatura. The richest and most influential were known as oligarchs, and they established a dominant position in the later years of the Yeltsin presidency. Only 15% of the 1993 business elite still retained their position by 2001, after the 1998 devaluation of the currency. Those who took their place were younger, less metropolitan, better educated and more likely to have a background in government, including many who had enjoyed ministerial status. The new business elite is less personally ambitious, but its political influence is no less considerable and its representation in decision-making bodies has more than doubled over the post-communist period. The logic of development is towards a concentration of economic power in the hands of 20e25 large conglomerates in a politically subordinate association with government, along South Korean lines.
Vegetation and climate change Since 14,81014C yr B.P. in southeastern uruguay and implications for the rise of early Formative societies
Authors: Iriarte José
Published: August 2005

This article presents a combined pollen and phytolith record of a 1.70-m sediment core from the wetlands of India Muerta (33°42′ S, 53°57′ W) in the lowland Pampa (grasslands) of southeastern Uruguay. Six14C dates and the pollen and phytolith content of the samples permitted the recognition of four distinct climatic periods between 14,85014C yr B.P. and the present. The Late Pleistocene period (between ca. 14,810 and ca. 10,00014C yr B.P.) was characterized by drier and cooler conditions indicated by the presence of a C3-dominated grassland. These conditions prevailed until the onset of the warmer and more humid climate of the Holocene around 945014C yr B.P. The early Holocene (between around 10,000 and 662014C yr B.P.) was characterized by the establishment of wetlands in the region as evidenced by the formation of black peat, the increase in wetland taxa, and the replacement of C3 Pooideae by C4 Panicoideae grasses. During the mid-Holocene, around 662014C yr B.P., began a period of environmental change characterized by drier climatic conditions, which resulted in the expansion of halophytic communities in the flat, low-lying areas of the wetlands of India Muerta. About 402014C yr B.P. a massive spike of Amaranthaceae/Chenopodiaceae coupled with a radical drop in wetland species indicates another major and more severe period of dryness. After ca. 400014C yr B.P., a decrease of halophytic species indicates the onset of more humid and stable climatic conditions, which characterized the late Holocene.

The findings reported in this article substantially improve our knowledge of the late Glacial and Holocene climate and vegetation in the region. The data provide a detailed record of the timing and severity of mid-Holocene environmental changes in southeastern South America. Significantly, the mid-Holocene drying trend coincided with major organizational changes in settlement, subsistence, and technology of the pre-Hispanic populations in the region, which gave rise to early Formative societies. This study also represents the first combined pollen and phytolith record for southeastern South America reinforcing the utility of phytoliths as significant indicators of long-term grassland dynamics.
Acquired resistance to berenil in a cloned isolate ofTrypanosoma evansiis associated with upregulation of a novel gene, TeDR40
Authors: WITOLA W. H. , TSUDA A. , INOUE N. , OHASHI K. , ONUMA M.
Published: August 2005

Drug resistance is now a severe and increasing problem in trypanosomes, but molecular details of mechanisms of resistance are only beginning to unveil. There is urgent need to clearly elucidate the different mechanisms of drug resistance in trypanosomes in order to circumvent existing resistance problems and avoid emergence of resistance to the next generation drugs. In this study, we cloned and characterized a novel gene, TeDR40, whose expression is associated with resistance to berenil inTrypanosoma evansi. Expression analysis showed that the gene was at least 1000-fold upregulated in resistant parasites and the encoded protein appeared to have a ubiquitous cellular localization. To investigate the association of TeDR40 with berenil-resistance, we genetically modified wild-type berenil-sensitiveT. evansifor inducible over-expression of the TeDR40 gene. Induction of over-expression of TeDR40 inT. evansiled to decreased (P<0·01) sensitivity to berenil. Our findings indicate a possible correlation between over-expression of a novel gene, TeDR40, and reduced sensitivity to berenil in anin vitro-cultured clonal line ofT. evansi.
Overwhelming O+ contribution to the plasma sheet energy density during the October 2003 superstorm: Geotail/EPIC and IMAGE/LENA observations
Authors: Nosé M. , Taguchi S. , Hosokawa K. , Christon S. P. , McEntire R. W. , Moore T. E. , Collier M. R.
Published: August 2005

We studied dynamics of O+ ions during the superstorm that occurred on 29–31 October 2003, using energetic (9–210 keV/e) ion flux data obtained by the energetic particle and ion composition (EPIC) instrument on board the Geotail satellite and neutral atom data in the energy range of 10 eV to a few keV acquired by the low‐energy neutral atom (LENA) imager on board the Imager for Magnetopause‐to‐Aurora Global Exploration (IMAGE) satellite. Since the low‐energy neutral atoms are created from the outflowing ionospheric ions by the charge exchange process, we could examine variations of ionospheric ion outflow with the IMAGE/LENA data. In the near‐Earth plasma sheet of XGSM ∼ −6 RE to −8.5 RE, we found that the H+ energy density showed no distinctive differences between the superstorm and quiet intervals (1–10 keV cm−3), while the O+ energy density increased from 0.05–3 keV cm−3 during the quiet intervals to ∼100 keV cm−3 during the superstorm. The O+/H+ energy density ratio reached 10–20 near the storm maximum, which is the largest ratio in the near‐Earth plasma sheet ever observed by Geotail, indicating more than 90% of O+ in the total energy density. We argued that such extreme increase of the O+/H+ energy density ratio during the October 2003 superstorm was due to mass‐dependent acceleration of ions by storm‐time substorms as well as an additional supply of O+ ions from the ionosphere to the plasma sheet. We compared the ion composition between the ring current and the near‐Earth plasma sheet reported by previous studies and found that they are rather similar. On the basis of the similarity, we estimated that the ring current had the O+/H+ energy density ratio as large as 10–20 for the October 2003 superstorm.
Modeling tephra sedimentation from a Ruapehu weak plume eruption
Authors: Bonadonna C. , Phillips J. C. , Houghton B. F.
Published: August 2005

We present a two‐dimensional model for sedimentation of well‐mixed weak plumes, accounting for lateral spreading of the cloud, downwind advection, increase of volumetric flux in the rising stage, and particle transport during fallout. The 17 June 1996 subplinian eruption of Ruapehu produced a bent‐over plume that rose to a height of 8.5 km in a wind field with an average velocity of 24 m s−1 and generated a narrow deposit on land extending up to 200 km from vent. The sedimentation from the Ruapehu plume was dominated by coarse ash, with all the blocks and most of the lapilli falling while the plume was still rising. Particles with diameter <125 μm show three accumulation maxima, one coincident with a secondary maximum in the total tephra deposit about 150 km from the vent. Numerical modeling shows that the plume started spreading horizontally beyond about 30 km from vent. Investigations also show that Fickian diffusion can be a good approximation to the crosswind spreading of both “vigorous” and “low‐energy” weak plumes, but a wide range of diffusion coefficients is to be expected, with the largest values necessary to describe the most vigorous weak plumes such as Ruapehu. One‐dimensional and two‐dimensional simulations show that tephra sedimentation must have been subvertical. This feature, also supported by direct observations, can be the result of the turbulence structure of the local wind field and convective instabilities, which could also have played an important role in the generation of the pronounced sinuosity shown by the Ruapehu deposit.
Toarcian oceanic anoxic event: An assessment of global causes using belemnite C isotope records
Authors: van de Schootbrugge B. , McArthur J. M. , Bailey T. R. , Rosenthal Y. , Wright J. D. , Miller K. G.
Published: August 2005

Two hypotheses have been proposed to explain simultaneous large negative excursions (up to 7‰ PeeDee belemnite) in bulk carbonate (δ13Ccarb) and organic carbon isotope records (δ13Corg) from black shales marking the Toarcian oceanic anoxic event (T‐OAE). The first explanation envisions recycling of dissolved inorganic carbon (DIC) with a light isotopic signature into the photic zone from the lower levels of a salinity‐stratified water mass, essentially requiring a regional paleoceanographic driver of the carbon cycle. The second involves the rapid and massive dissociation of methane from gas hydrates that effectively renders the T‐OAE a global perturbation of the carbon cycle. We present C isotope records from belemnites (δ13Cbel) sampled from two localities, calibrated with high‐resolution ammonite biostratigraphy and Sr isotope stratigraphy, in Yorkshire (England) and Dotternhausen (Germany), that can be used to assess which model best explains the observed changes in carbon isotopes. Our records of the δ13C composition of belemnite calcite do not show the large negative C isotope excursions shown by coeval records of δ13C in sedimentary organic matter or bulk sedimentary carbonate. It follows that isotopically light carbon cannot have dominated the ocean‐atmosphere carbon reservoir during the Toarcian OAE, as would be required were the methane release hypothesis correct. On the basis of an evaluation of available carbon isotope records we discuss a model in which the recycling of DIC from the deeper levels of a stratified water body, and shallowing of anoxic conditions into the photic zone, can explain all isotopic profiles. In particular, the model accounts for the higher C isotope values of belemnites that are characteristic of open ocean, well‐mixed conditions, and the lower C isotope values of neritic phytoplankton communities that recorded the degree of density stratification and shallowing of anoxia in the photic zone.
Decadal change in relationship between east Asian and WNP summer monsoons
Authors: Kwon MinHo , Jhun Jong‐Ghap , Wang Bin , An Soon‐Il , Kug Jong‐Seong
Published: August 2005

It has been recognized that the intensity of the east Asian (EA) summer monsoon has a negative correlation with that of the western North Pacific (WNP) summer monsoon. Here we show that this relationship is much stronger in the recent decade (1994–2004) than in the epoch before 1994 (1979–1993). The first two leading modes of summer‐mean precipitation over the large region of the WNP and EA region are shown to be associated with two factors: the ENSO development and the WNP summer monsoon fluctuation. The leading mode has changed from an ENSO‐related mode in 1979–1993 to a WNP summer monsoon‐related mode in the recent decade (1994–2004). The summer‐mean mid‐tropospheric geopotential heights that are correlated with the WNP monsoon index also show a marked change in the teleconnection (wave‐train) pattern between 1994–2004 and 1979–1993. All together this evidence suggests that the relationship between the EA and the WNP summer monsoons has experienced a significant decadal change around 1993–1994.
Response of a coupled chemistry‐climate model to changes in aerosol emissions: Global impact on the hydrological cycle and the tropospheric burdens of OH, ozone, and NOx
Authors: Lamarque J.‐F. , Kiehl J. T. , Hess P. G. , Collins W. D. , Emmons L. K. , Ginoux P. , Luo C. , Tie X. X.
Published: August 2005

In this study, we analyze the response of the coupled chemistry‐climate system to changes in aerosol emissions in fully coupled atmospheric chemistry‐climate‐slab ocean model simulations; only the direct radiative effect of aerosols and their uptake of chemical species are considered in this study. We show that, at the global scale, a decrease in emissions of the considered aerosols (or their precursors) produces a warmer and moister climate. In addition, the tropospheric burdens of OH and ozone increase when aerosol emissions are decreased. The ozone response is a combination of the impact of reduced heterogeneous uptake of N2O5 and increased ozone loss in a moister atmosphere. Under reduced aerosol emissions, the tropospheric burden of NOx (NO + NO2) is strongly reduced by an increase in nitric acid formation but also increased by the reduced N2O5 uptake. Finally, we discuss the significant difference found between the combined impact of all aerosols emissions and the sum of their individual contributions.
Probabilistic analysis of rockfall frequencies during an andesite lava dome eruption: The Soufrière Hills Volcano, Montserrat
Authors: Calder E. S. , Cortés J. A. , Palma J. L. , Luckett R.
Published: August 2005

A probabilistic analysis of rockfalls has been undertaken using seismometer‐determined information on the timing and duration of rockfalls from the Soufrière Hills lava dome, Montserrat, between 1995 and 1997. Repose intervals between rockfalls fit log logistic survivor distributions. Differences in the log logistic survivor function for different sub‐sets of data are accommodated by variation of the parameter k, which varies from 0.7 to 1.6, and sample median, μ. When extrusion rate is assumed to be ≈0 m3/s, k is ≤1 denoting that the hazard function has a continuously decreasing form, contrasting to the hazard maximum present during periods of extrusion. This analysis illustrates a direct relationship between k, μ, and lava extrusion rate. Extrusion rate becomes increasingly significant in determining rockfall frequencies when rates are relatively high, whereas other factors become increasingly significant when rates are low.
Simulations of fine particulate matter (PM2.5) in Houston, Texas
Authors: Fan Jiwen , Zhang Renyi , Li Guohui , Nielsen‐Gammon John , Li Zhanqing
Published: August 2005

Simulations of fine particulate matter (PM2.5) during an eight‐day episode (24 to 31 August 2000) is conducted in association with the 2000 Texas Air Quality Study (TexAQS 2000) and the Houston Supersite Project using the EPA's Models‐3 Community Multiscale Air Quality model (CMAQ). The mass concentrations of PM2.5 and major chemical constituents during the episode are calculated and compared with available field measurements. The predicted daily PM2.5 mass concentrations are about 8.5–13.0 μg/m3, consistent with the observed values. The diurnal patterns of PM2.5 mass concentrations are similar throughout the region, with a strong morning peak and a weak peak in the late afternoon to the early evening. High primary emissions, high formation rates of the secondary fine particulate matter, and low planetary boundary layer (PBL) heights contribute to the morning peak. The major components of the fine particulate matter in this region are sulfate, organic carbon, elemental carbon and ammonium. The model predicts about 30% sulfate, 32% organics (including elemental carbon (EC)), and 10% ammonium of the total PM2.5 mass. The balance of the primary cations and anions indicates that fine particulate matter in this region is acidic. Comparison with field observation reveals that CMAQ produces good simulations of averaged daily mass concentrations of major components such as sulfate, organic carbon, elemental carbon and ammonium with normalized mean biases (NMB) of less than ±25%. Uncertainties in the aerosol precursor emissions, the aerosol chemistry especially about secondary organic aerosol (SOA) formation and aqueous reactions, and the calculated PBL heights are likely responsible for the differences.
Discrimination of glass and phyllosilicate minerals in thermal infrared data
Authors: Koeppen William C. , Hamilton Victoria E.
Published: August 2005

Thermal infrared spectra of glasses and phyllosilicates have similar shapes leading to a proposed ambiguity in deconvolution results. We quantify the spectral separability of these two classes using discriminant analysis and linear deconvolution. We apply the deconvolution technique to single spectra, and two‐ and four‐component mixtures. Missing end‐members result in quantifiable uncertainties between modeled abundances of glasses and phyllosilicates. Mixtures containing silica‐K2O glass are susceptible to overestimating phyllosilicates with minimal increases in root‐mean‐square error if the silica‐K2O glass spectrum is not present in the end‐member set. Missing phyllosilicate end‐members are likely to be modeled as combinations of other phyllosilicates rather than glasses, with saponite, nontronite, and halloysite showing the highest uncertainties. Empirically, ±15% of the total glass plus phyllosilicate abundance incorporates all uncertainties in derived glass abundance if the glass in the mixture is in the end‐member set. If the glass in the mixture is excluded from the end‐member set, these uncertainties increase to ±65%. Four‐component mixtures show that glasses and phyllosilicates act as a two‐component mixing system but can induce small uncertainties in other components. Applying the maximum derived uncertainties to deconvolutions of surface type 2, measured by the Mars Global Surveyor Thermal Emission Spectrometer, we find that silica‐K2O glass abundance is above the instrument detection limit and a likely component of the surface. Pure silica glass, a proposed amorphous weathering product, is the least likely candidate for confusion with phyllosilicates and its noninclusion in models of Martian spectra suggests it likely is not a component of the Martian surface.
Preparing transition-metal clusters in known structural forms: The mass-analyzed threshold ionization spectrum of V3
Authors: Ford Mark S. , Mackenzie Stuart R.
Published: August 2005

The first results are presented of a new experiment designed both to generate and characterize spectroscopically individual isomers of transition-metal cluster cations. As a proof of concept the one-photon mass-analyzed threshold ionization (MATI) spectrum of V3 has been recorded in the region of 44000–45000cm−1. This study extends the range of a previous zero-kinetic-energy (ZEKE) photoelectron study of Yang et al. [Chem. Phys. Lett. 231, 177 (1994)] with which the current results are compared. The MATI spectra reported here exhibit surprisingly high resolution (0.2cm−1) for this technique despite the use of large discrimination and extraction fields. Analysis of the rotational profile of the origin band allows assignment of the V3 ground state as A1′2 and the V3+ ground state as A2′3, both with D3h geometry, in agreement with the density-functional theory study of the V3 ZEKE spectrum by Calaminici et al. [J. Chem. Phys. 114, 4036 (2001)]. There is also some evidence in the spectrum of transitions to the low-lying A1′1 excited state of the ion. The vibrational structure observed in the MATI spectrum is, however, significantly different to and less extensive than that predicted in the density-functional theory study. Possible reasons for the discrepancies are discussed and an alternative assignment is proposed which results in revised values for the vibrational wave numbers of both the neutral and ionic states. These studies demonstrate the efficient generation of cluster ions in known structural (isomeric) forms and pave the way for the study of cluster reactivity as a function of geometrical structure.
Unusual hydrogen bonding behavior in binary complexes of coinage metal anions with water
Authors: Schneider Holger , Boese A. Daniel , Weber J. Mathias
Published: August 2005

We have studied the interaction of atomic coinage metal anions with water molecules by infrared photodissociation spectroscopy of M−∙H2O∙Arn clusters (M=Cu, Ag, Au; n=1, 2). We compare our observations with calculations on density-functional and coupled cluster levels of theory. The gold anion is bound to the water molecule by a single ionic hydrogen bond, similar to the halide-water complexes. In contrast, zero-point motion in the silver and copper complexes leads to a deviation from this motif.
Stable confinement of toroidal electron plasma in an internal conductor device Prototype-Ring Trap
Authors: Saitoh H. , Yoshida Z. , Watanabe S.
Published: August 2005

A pure electron plasma has been produced in an internal conductor device Prototype-Ring Trap (Proto-RT). The temporal evolution of the electron plasma was investigated by the measurement of electrostatic fluctuations. Stable confinement was realized when the potential profile adjusted to match the magnetic surfaces. The confinement time varies as a function of the magnetic field strength and the neutral gas pressure, and is comparable to the diffusion time of electrons determined by the classical collisions with neutral gas. Although the addition of a toroidal magnetic field stabilized the electrostatic fluctuation of the plasma, the effects of the magnetic shear shortened the stable confinement time, possibly because of the obstacles of coil support structures.
Power loss in open cavity diodes and a modified Child-Langmuir law
Authors: Biswas Debabrata , Kumar Raghwendra , Puri R. R.
Published: August 2005

Diodes used in most high power devices are inherently open. It is shown that under such circumstances, there is a loss of electromagnetic radiation leading to a lower critical current as compared to closed diodes. The power loss can be incorporated in the standard Child-Langmuir framework by introducing an effective potential. The modified Child-Langmuir law can be used to predict the maximum power loss for a given plate separation and potential difference as well as the maximum transmitted current for this power loss. The effectiveness of the theory is tested numerically.