bluuebunny/crossref_metadata_2025 huggingface dataset:
Population Pharmacokinetics of the Novel Anticancer Agent E7070 During Four Phase I Studies: Model Building and Validation
Authors: van Kesteren Ch. , Mathôt R. A.A. , Raymond E. , Armand J. P. , Dittrich Ch. , Dumez H. , Roché H. , Droz J. P. , Punt C. , Ravic M. , Wanders J. , Beijnen J. H. , Fumoleau P. , Schellens J. H.M.
Published: September 2002

PURPOSE: N-(3-Chloro-7-indolyl)-1,4-benzenedisulfonamide (E7070) is a novel sulfonamide anticancer agent currently in phase II clinical development for the treatment of solid tumors. Four phase I studies have been finalized, with E7070 administered at four different treatment schedules to identify the maximum-tolerated dose and the dose-limiting toxicities. Pharmacokinetic analyses of all studies revealed E7070 to have nonlinear pharmacokinetics. A population pharmacokinetic model was designed and validated to describe the pharmacokinetics of E7070 at all four treatment schedules and to identify the possible influences of patient characteristics on the pharmacokinetic parameters.

PATIENTS AND METHODS: Plasma concentration-time data of all patients (n = 143) were fitted to several pharmacokinetic models using NONMEM. Seventeen covariables were investigated for their relation with individual pharmacokinetic parameters. A bootstrap procedure was performed to check the validity of the model.

RESULTS: The data were best described using a three-compartment model with nonlinear distribution to a peripheral compartment and two parallel pathways of elimination from the central compartment: a linear and a saturable pathway. Body-surface area (BSA) was significantly correlated to both the volume of distribution of the central compartment and to the maximal elimination capacity. The fits of 500 bootstrap replicates of the data set demonstrated the robustness of the developed population pharmacokinetic model.

CONCLUSION: A population pharmacokinetic model has been designed and validated that accurately describes the data of four phase I studies with E7070. Furthermore, it has been demonstrated that BSA-guided dosing for E7070 is important.
Phase I Clinical and Pharmacokinetic Study of Flavopiridol Administered as a Daily 1-Hour Infusion in Patients With Advanced Neoplasms
Authors: Tan Antoinette R. , Headlee Donna , Messmann Richard , Sausville Edward A. , Arbuck Susan G. , Murgo Anthony J. , Melillo Giovanni , Zhai Suoping , Figg William D. , Swain Sandra M. , Senderowicz Adrian M.
Published: September 2002

PURPOSE: To define the maximum-tolerated dose (MTD), dose-limiting toxicity, and pharmacokinetics of the cyclin-dependent kinase inhibitor flavopiridol administered as a daily 1-hour infusion every 3 weeks.

PATIENTS AND METHODS: Fifty-five patients with advanced neoplasms were treated with flavopiridol at doses of 12, 17, 24, 30, 37.5, and 52.5 mg/m2/d for 5 days; doses of 50 and 62.5 mg/m2/d for 3 days; and doses of 62.5 and 78 mg/m2/d for 1 day. Plasma sampling was performed to characterize the pharmacokinetics of flavopiridol with these schedules.

RESULTS: Dose-limiting neutropenia developed at doses ≥ 52.5 mg/m2/d. Nonhematologic toxicities included nausea, vomiting, diarrhea, hypotension, and a proinflammatory syndrome characterized by anorexia, fatigue, fever, and tumor pain. The median peak concentrations of flavopiridol achieved at the MTDs on the 5-day, 3-day, and 1-day schedule were 1.7 μmol/L (range, 1.3 to 4.2 μmol/L), 3.2 μmol/L (range, 1.7 to 4.8 μmol/L), and 3.9 μmol/L (1.8 to 5.1 μmol/L), respectively. Twelve patients had stable disease for ≥ 3 months, with a median duration of 6 months (range, 3 to 11 months).

CONCLUSION: The recommended phase II doses of flavopiridol as a 1-hour infusion are 37.5 mg/m2/d for 5 days, 50 mg/m2/d for 3 days, and 62.5 mg/m2/d for 1 day. Flavopiridol as a daily 1-hour infusion can be safely administered and can achieve concentrations in the micromolar range, sufficient to inhibit cyclin-dependent kinases in preclinical models. Further studies to determine the optimal schedule of flavopiridol as a single agent and in combination with chemotherapeutic agents are underway.
Use of Epoetin in Patients With Cancer: Evidence-Based Clinical Practice Guidelines of the American Society of Clinical Oncology and the American Society of Hematology
Authors: Rizzo J. Douglas , Lichtin Alan E. , Woolf Steven H. , Seidenfeld Jerome , Bennett Charles L. , Cella David , Djulbegovic Benjamin , Goode Matthew J. , Jakubowski Ann A. , Lee Stephanie J. , Miller Carole B. , Rarick Mark U. , Regan David H. , Browman George P. , Gordon Michael S.
Published: September 2002

ABSTRACT: Anemia resulting from cancer, or its treatment, is an important clinical problem increasingly treated with the recombinant hematopoietic growth factor erythropoietin. To address uncertainties regarding indications and efficacy, the American Society of Clinical Oncology and the American Society of Hematology developed an evidence-based clinical practice guideline for the use of epoetin in patients with cancer. The guideline panel found good evidence to recommend use of epoetin as a treatment option for patients with chemotherapy-associated anemia with a hemoglobin level less than 10 g/dL. Use of epoetin for patients with less severe anemia (hemoglobin < 12 g/dL but never below 10 g/dL) should be determined by clinical circumstances. Good evidence from clinical trials supports the use of subcutaneous epoetin thrice weekly (150 U/kg tiw) for a minimum of 4 weeks. Less strong evidence supports an alternative weekly (40,000 U/wk) dosing regimen, based on common clinical practice. With either administration schedule, dose escalation should be considered for those not responding to the initial dose. In the absence of response, continuing epoetin beyond 6 to 8 weeks does not appear to be beneficial. Epoetin should be titrated once the hemoglobin concentration reaches 12 g/dL. Evidence from one randomized controlled trial supports use of epoetin for patients with anemia associated with low-risk myelodysplasia not receiving chemotherapy; however, there are no published high-quality studies to support its use for anemia in other hematologic malignancies in the absence of chemotherapy. Therefore, for anemic patients with hematologic malignancies, it is recommended that physicians initiate conventional therapy and observe hematologic response before considering use of epoetin.
Organ Preservation Therapy Using Induction Plus Concurrent Chemoradiation for Advanced Resectable Oropharyngeal Carcinoma: A University of Pennsylvania Phase II Trial
Authors: Machtay Mitchell , Rosenthal David I. , Hershock Diane , Jones Heather , Williamson Shirnett , Greenberg Michael J. , Weinstein Gregory S. , Aviles Victor M. , Chalian Ara A. , Weber Randal S.
Published: September 2002

PURPOSE: To determine the efficacy, feasibility, and toxicity of a new regimen for locally advanced oropharyngeal carcinoma.

PATIENTS AND METHODS: Patients had technically resectable stage III/IV squamous cell carcinoma of the oropharynx, exclusive of T1-2N1. Induction chemotherapy consisted of carboplatin (area under the curve formula equal to 6) and paclitaxel 200 mg/m2 for two cycles, followed by re-evaluation. Patients with major response continued to definitive radiotherapy (70 Gy over 7 weeks) plus concurrent once-weekly paclitaxel (30 mg/m2/wk). Patients with advanced neck disease also underwent post–radiation therapy neck dissection and two more chemotherapy cycles.

RESULTS: Fifty-three patients were enrolled. Median follow-up was 31 months (minimum follow-up for survivors was 18 months). The major response rate to induction chemotherapy was 89%; 90% of patients had a complete response after concurrent chemoradiation. Actuarial survival at 3 years was 70%, and 3-year event-free survival was 59%. The 3-year actuarial locoregional control was 82% and the 3-year actuarial rate of distant metastases was 19%. Organ preservation was achieved in 77% of all patients. One patient (2%) died during therapy. Late grade 3 toxicity occurred in 24% of patients, consisting mainly of chronic dysphagia/aspiration and/or radiation soft tissue ulceration. The treatment-related mortality rate was 4% (two patients died from respiratory failure).

CONCLUSION: Response to induction chemotherapy as studied in this trial was not useful as a predictive marker for ultimate outcome or organ conservation. Overall, however, this regimen offers good disease control and survival for patients with locally advanced oropharyngeal carcinoma, comparable with other concurrent chemoradiation programs. Further study of similar protocols is indicated.
Adjuvant Chemotherapy Use for Medicare Beneficiaries With Stage II Colon Cancer
Authors: Schrag Deborah , Rifas-Shiman Sheryl , Saltz Leonard , Bach Peter B. , Begg Colin B.
Published: September 2002

PURPOSE: Clinical trials have not demonstrated that adjuvant chemotherapy improves survival for patients with resected stage II colon cancer. Nevertheless, patients may receive this treatment despite its uncertain benefit. The objective of this study was to determine the extent to which adjuvant chemotherapy is used for patients with stage II colon cancer.

PATIENTS AND METHODS: Using the Surveillance, Epidemiology, and End Results-Medicare linked database, we identified 3,151 patients aged 65 to 75 with resected stage II colon cancer and no adverse prognostic features. The primary outcome was chemotherapy use within 3 months of surgery ascertained from claims submitted to Medicare. Relationships between patient characteristics and adjuvant chemotherapy use were measured and their significance was assessed using multivariable logistic regression. Survival for treated and untreated patients was compared using a Cox model.

RESULTS: Twenty-seven percent of patients received chemotherapy during the 3 postoperative months. Younger age at diagnosis, white race, unfavorable tumor grade, and low comorbidity were each associated with a greater likelihood of receiving treatment. Sex, the number of examined lymph nodes in the tumor specimen, the urgency of the surgical admission, and median income was each unrelated to treatment. Five-year survival was 75% for untreated patients and 78% for treated patients. After adjusting for known between-group differences, the hazard ratio for survival associated with adjuvant treatment was 0.91 (95% confidence interval, 0.77 to 1.09).

CONCLUSION: A substantial percentage of Medicare beneficiaries with resected stage II colon cancer receive adjuvant chemotherapy despite its uncertain benefit.
Global warming potentials modified for surface radiative forcing for use in surface energy balance models
Authors: Evans W. F. J. , Puckrin E.
Published: October 2002

The radiative impact of greenhouse gases in warming the Earth varies significantly, depending on whether one considers the forcing at the tropopause or at the surface. Compared to the former, the surface forcing for some greenhouse gases is reduced by the interference of water vapour. Hence, we calculate alternative surface global warming potentials (SGWPs) that are derived from the surface forcing radiation of greenhouse gases for potential use in surface radiative energy balance models (SREBMs). For gases with a large water vapour overlap, the SGWPs are typically 30% smaller than current GWPs; for gases with relatively little overlap, the SGWPs are larger by more than 33%. These results may be used in conjunction with SREBMs as an additional means of calculating climate change, and may lead to an altered emissions budget compared to that outlined by the current Kyoto agreement. Copyright © 2003 Royal Meteorological Society.
Variation in Soil-Catena Characteristics of Moraines with Time and Climate, South Island, New Zealand
Authors: Birkeland Peter W.
Published: October 2002

Soil catenas on three moraines in each of two areas with different climate were studied to determine (a) downcatena soil differentiation with climate and time and (b) their usefulness in estimating the relative ages of the underlying deposits. In the dry area (mean annual precipitation (MAP), ca. 0.5 m) all soils have A/Bw/C profiles formed in loess/till. Their similarity in morphology and in most chemical characteristics with catena position and age suggests that the low MAP does not result in much redistribution of water, elements, or sediment downcatena. This similarity also suggests ages close to each other and correlation with the Otiran Glaciation (oxygen-isotope stages 2 and 4). In the wet area (MAP ca. 3 m) the soils also formed in loess/till and with time (a) soil morphology progresses from A/Bw/C to A/E/B/C, (h) reduced properties intensify, especially in the downcatena profiles, (c) citrate-bicarbonate-dithionite-extractable Fe displays accumulation in the youngest catena followed by loss in the older catenas, and (d) downcatena trends in total chemical data display marked losses of the more mobile elements. These data demonstrate that although catena development is rapid in a wet climate, the downcatena contrast can be muted with time due to a change from processes dominated by oxidation to those dominated by reduction. Soil catena properties in the wet area are sufficiently different to not refute age estimations suggested by Suggate (1990): youngest moraine, oxygen-isotope stage 2; intermediate moraine, isotope stage 4; and oldest moraine, isotope stage 10. An unresolved problem in both areas is the possibility of soil erosion to foul soil-age relations.
Seismic-Reflection Identification of Susquehanna River Paleochannels on the Mid-Atlantic Coastal Plain
Authors: Genau Robert B. , Madsen John A. , McGeary Susan , Wehmiller John F.
Published: October 2002

Land-based, high-resolution seismic-reflection methods were used to image Quaternary paleochannels of the Susquehanna River system. Using a portable, 12-channel signal-enhancing seismograph, 12 accelerometers as receivers, and a 4.54-kg sledge hammer struck against an aluminum plate as a source, a sixfold, multichannel seismic profile 2.5 km long was acquired at Taylors Island, Maryland. On the processed seismic profile, pronounced high-amplitude seismic reflections delineate the unconformity between Quaternary and underlying Tertiary sediments and the disconformable contact separating Miocene and Eocene deposits. Subsurface-seismic stratigraphic relationships that clearly indicate the presence of two paleochannels were observed, one believed to be the Exmore paleochannel, projected to underlie northern Taylors Island based on marine seismic data. An overlapping sequence of fill sediments was observed on the eastern margin of the Exmore paleochannel. The second paleochannel may be a tributary of the Exmore or possibly the western edge of the younger Eastville paleochannel. Results from this study indicate that land-based, shallow, high-resolution seismic-reflection data can be used to delineate subsurface geomorphology successfully in coastal plain environments. This technique of defining erosional surfaces and depositional units beneath present land areas, when integrated with chronostratigraphic data, is a powerful tool for developing a better understanding of the Quaternary record.
Stable Isotope and Lithologic Evidence of Late-Glacial and Holocene Oceanography of the Northwestern Pacific and Its Marginal Seas
Authors: Gorbarenko Sergei A.
Published: October 2002

Stable isotopes, geochemical, lithological, and micropaleontological results from cores from the far northwest (FNW) Pacific and the Okhotsk and Bering seas are used to reconstruct the regional environment for the last glaciation, the deglacial transition, and the Holocene. δ18O records of planktonic foraminifera of the region show two “light” shifts during deglacial time, provoked by the freshening of the surface water and climate warming. These north Pacific terminal events (T1ANP and T1BNP) with ages of 12,500 and 9300 yr B.P., respectively, occur almost simultaneously with two episodes of accelerated glacier melting around the North Atlantic. Along with the isotopic shifts, the CaCO3 content in regional sediments increased abruptly (1A and 1B carbonate peaks), probably due to changes of productivity and pore water chemistry of surface sediments. Organic matter and opal concentration increased during the transition (between T1ANP and T1BNP events) in the sediments of the FNW Pacific and the southern part of the Bering Sea and opal content increased in the Holocene in the Bering and Okhotsk Seas. δ13C records of cores from the Okhotsk and Bering seas and the FNW Pacific do not contradict the hypothesis of increased intermediate water formation in the region during glaciation. During deglaciation, accumulation of the coarse terrigenous component decreased in sediments of the Bering Sea and the FNW Pacific before the T1ANP event, probably as a result of rising sea level and opening of the Bering Strait.
Alluvial Pollen on the North China Plain
Authors: Qinghai Xu , Xiaolan Yang , Chen Wu , Lingyao Meng , Zihui Wang
Published: October 2002

Mordern alluvial pollen varies with geomorphic setting and depositional facies in sediments of the Yellow, Hutuo, and Luan rivers and in Baiyangdian and Hengshuihu lakes. Most of the arboreal pollen is derived from the mountains, whereas most of the nonarboreal pollen is derived from the plain itself. Alluvium dominated by Pinus pollen and Selaginella spores was deposited during a flood. Hydrodynamic sorting of alluvial pollen exists in the sediments of floodplain, central bar, natural levees, and point bar. In reconstructing the ancient vegetation and past climate based on pollen in alluvium, it is important to consider sedimentary facies and geomorphologic setting.
Morphology and Weathering Trends of the Sangamon Soil Complex in South-Central Indiana in Relation to Paleodrainage
Authors: Jacobs Peter M.
Published: October 2002

Three paleodrainage groups are proposed for profiles of the Farmdale–Sangamon soil complex in south-central Indiana. The groups (good, intermediate, and poor) are differentiated on the basis of matrix colors and color patterns. Genetic support for the groupings is provided by morphological trends still evident following > 100,000 yr of pedogenesis and burial by late Wisconsinan loess. Depth of carbonate leaching, solum thickness, and argillic horizon thickness all decrease with poorer drainage. Clay mineralogy also reflects paleodrainage. Illite degradation is intense in all profiles, but profiles with good drainage have poorly crystalline, interstratified expandable minerals, while well crystalline smectites dominate in profiles with poor drainage. Remanent aggregation in former A horizons is stronger in more poorly drained profiles, while the effects of structural overprinting from the modern soil increase with better modern drainage. Soil morphology, mineralogy, and parent material–paleolandscape position of Sangamon profiles are all internally consistent with color development under soil hydrological conditions during the last interglacial to glacial transition. The occurrence frequency of each drainage group indicates that the Sangamon soilscape was better drained than now, and morphology and clay mineral evidence suggests that areas with poor drainage did not experience the extreme seasonal groundwater shifts that the modern landscape experiences.
Holocene Sea-Level Record on Funafuti and Potential Impact of Global Warming on Central Pacific Atolls
Authors: Dickinson William R.
Published: October 2002

Geomorphic features inherited from the mid-Holocene glacio-hydro-isostatic sea-level highstand that affected the central Pacific region influence the susceptibility of atoll islets to potentially enhanced wave erosion associated with rise in sea level from global warming. Shoreline morphology on multiple islets of Funafuti atoll in central Tuvalu reflects a relative mid-Holocene sea-level highstand 2.2–2.4 m above modern sea level. Typical islets are composed of unconsolidated post-mid-Holocene sediment resting disconformably on cemented coral rubble formed beneath now-emergent mid-Holocene reef flats. Exposed remnants of the lithified islet foundations serve as resistant buttresses protecting the flanks of atoll islets from wave attack. Islets lacking cemented mid-Holocene deposits as part of their internal structure are migratory sand cays with unstable shorelines. Any future sea-level rise ≥0.75 m, bringing high tide above the elevation of mid-Holocene low tide, might trigger enhanced wave erosion of stable atoll islets by overtopping the indurated mid-Holocene reef platforms. As analogous threshold relations are inferred for other central Pacific atolls, the risk of future inundation of island nations cannot be evaluated solely in terms of expected sea-level rise with respect to gross islet elevations.
Nitric oxide synthesis is involved in arterial haptoglobin expression after sustained flow changes
Authors: Smeets Mirjam B , Pasterkamp Gerard , Lim Sai-Kiang , Velema Evelyn , van Middelaar Ben , de Kleijn Dominique P.V
Published: October 2002

The acute phase protein haptoglobin is highly expressed in arteries after sustained flow changes and involved in cell migration and arterial restructuring. In the liver, haptoglobin expression is mainly regulated by interleukin‐6 (IL‐6). In the artery, shear stress and NO influence IL‐6 expression. In the present study, we demonstrate that NO synthesis is involved in the regulation of arterial haptoglobin expression after sustained flow changes. Decreased haptoglobin expression after NO inhibition coincided with decreased IL‐6 levels. However, IL‐6 knockout mice had normal arterial haptoglobin expression levels after sustained flow changes suggesting that other mediators may provide compensatory mechanisms for the regulation of arterial haptoglobin expression.
Changing Windows on a Changing China: The Evolving “Think Tank” System and the Case of the Public Security Sector
Authors: Tanner Murray Scot
Published: October 2002

The entrepreneurial “second generation” of Chinese policy research institutes (often called think tanks) that emerged during the 1980s played a pivotal role in the policy process of reform. Since Tiananmen, China's growing commercialization is spawning a “third generation” of think tanks characterized by even more ambiguous links to sponsoring leaders and institutions, greatly expanded commercial links, greater exposure to Western theories and techniques, and the gradual emergence of wide-ranging “policy communities.” The extent of this change varies greatly across policy sectors, however. Generational change is evident in China's previously unstudied network of public security (police) think tanks. Though clearly still of the “second generation” variety, these institutes have been in the forefront of importing and incorporating more sophisticated crime-fighting techniques and less class-based and conspiratorial theories of crime and social unrest.
Alternate Civilities: Democracy and Culture in China and Taiwan. By Robert P. Weller. [Boulder, CO: Westview Press, 1999. xvi+172 pp. $28.00. ISBN 0-8133-3931-6.]
Authors: Gold Thomas B.
Published: October 2002

Robert Weller has given us a virtuoso display of theoretical sophistication combined with rich primary data in a densely packed yet consistently stimulating volume. Recognizing the controversy over the applicability of the concept of “civil society” to areas outside the West, he elaborates the idea of an “alternate civility,” by which he means forms of association between the family and the state deeply rooted in society at the grassroots level (therefore not broad-based enough to qualify as “civil”) that, in his view, have provided the basis for Taiwan's democratic transition, and may provide the seeds for a similar political transformation in mainland China. He calls this the “informal social sector” and contrasts it with a sector comprising formal organizations, which are more likely to be co-opted by the state.
Assessment of the use of n-alkanes as markers to describe the complex diets of herbivores
Authors: MARTINS H. , ELSTON D. A. , MAYES R. W. , MILNE J. A.
Published: October 2002

Previous approaches to the description of complex diets, based on n-alkanes and optimization techniques, have grouped the plant species to reduce the number of components. Diet estimates have been obtained with least-squares routines by minimizing the discrepancy between faecal alkane concentrations calculated from herbage concentrations and actual faecal alkane concentrations. The effect of diet selection within groups can only be assessed by using sensitivity tests or by giving subjective weights to the individual plants. In the current study, a new optimization algorithm was developed that selects weightings that lead to consistent estimates of group proportions. The diet of the wild rabbit in a southern Portuguese montado was used as a case study. Estimates of the diet composition obtained using the new algorithm were compared with those of a conventional routine. The new algorithm was shown to provide, on average, more accurate estimates of the proportions of the groups in the diet. The effect of grouping plant species according to criteria other than similarity in n-alkane pattern on the accuracy of estimates was shown to be non-significant.
Effect of manure handling system, N fertilizer use and area of sugar beet on N surpluses from dairy farms in southern Sweden
Authors: SWENSSON CHRISTIAN
Published: October 2002

Nitrogen balances from 283 conventional dairy farms situated in southern Sweden were investigated using the farm gate method. Nitrogen balances were determined for 1997 and 1998. Three N balances were calculated; for the whole farm, for crop production and for milk production. The aims of the investigation were to study if factors such as manure handling system, the amount of N obtained from mineral fertilizer per hectare and the proportion of sugar beet have an influence on the N balance. There was no significant effect of manure handling system on the N surplus per hectare or on N efficiency. The results showed that N efficiency was significantly improved by including sugar beet in the crop rotation and was negatively correlated with milk yield per hectare and fertilizer N per hectare. The N surplus per hectare was positively correlated with milk yield per hectare and fertilizer N per hectare. The comparison did not find a strong relationship between the amounts of N obtained from mineral fertilizer per hectare and supplied as manure. The latter was calculated theoretically. There was a weak, but significant, negative correlation between N from manure in 1997 and N from mineral fertilizer in 1998.
The description of the rate of protein and lipid growth in pigs in relation to live weight
Authors: WHITTEMORE C. T. , GREEN D. M.
Published: October 2002

The paper seeks to compare the effectiveness of various functions as appropriate to express protein retention and lipid retention as a function of pig live weight. Linear descriptors were adequate for protein growth over the 20 to 120 kg live weight range, but not adequate when higher live weights were included. Linear descriptors were not adequate for lipid growth over any weight range. Quadratic and cubic polynomials, and the logistic function, were faulted on their failure to describe the known biology. Augmentation of the allometric function added nothing to the simple form. The Gompertz function was consistently effective for the description of daily protein retention rate. The Bridges and Richards functions are more flexible than the Gompertz with respect to the point of inflection, but when applied they resembled the Gompertz and therefore did not materially influence the descriptive outcome. The cubic polynomial, augmented allometric, Bridges and Richards functions, although favoured in other reports, were found to add nothing to the more simple functions. It is concluded that protein retention can be well expressed in relation to live weight by linear and Gompertz functions. Lipid retention could be well described by an allometric relationship with pig mass.
Effect of high-temperature short-time (HTST) laboratory pasteurization on the survival of Burkholderia cepacia complex organisms in whole, low fat and skimmed milks
Authors: MOORE JOHN E. , CHERIE MILLAR B. , BUCKLEY THOMAS , CROWE MARY , STUART ELBORN J.
Published: October 2002

Cystic fibrosis (CF) is the most common genetic disease of Caucasians with an
incidence of 1 in 2500 live births and a carriage rate of 1 in 20 individuals. CF patients
continue to suåer from recurrent and chronic respiratory tract infections and most
of their morbidity and mortality is due to such infections throughout their life
(Høiby, 1991). These infections are usually dominated by Gram-negative organisms,
especially by the pseudomonads including in particular, Pseudomonas aeruginosa, as
well as members of the Burkholderia cepacia complex of organisms.
‘Birthday effect’ on the adoption of alternative mating tactics in Zosterisessor ophiocephalus: evidence from a growth model
Authors: Pastres Roberto , Pranovi Fabio , Libralato Simone , Malavasi Stefano , Torricelli Patrizia
Published: October 2002

The present study aims to apply a growth model to a species with a conditional reproductive strategy, the grass goby Zosterisessor ophiocephalus (Pisces: Gobiidae), in order to evaluate the adoption of alternative tactics by this species under the constraints of different dates of birth. The model describes the growth pattern (based on age, weight and gonadosomatic index data) of an individual, assumed to be representative of a given cohort, while also taking into account the energetic loss due to parental care. The most important parameters have been calibrated by comparing the results with a set of data collected in the lagoon of Venice. The comparison between the growth pattern of a parental male and that of a late-born male suggests that the birthday could be one of the major constraints affecting the adoption of an alternative tactic during the first breeding season.
The hit problem for symmetric polynomials over the Steenrod algebra
Authors: JANFADA A. S. , WOOD R. M. W.
Published: October 2002

We cite [18] for references to work on the hit problem for the polynomial algebra
P(n) = [ ]2[x1, ;…, xn] =
[oplus ]d[ges ]0Pd(n), viewed as a graded left module over the Steenrod algebra [Ascr ] at the prime 2. The grading is by the homogeneous polynomials Pd(n)
of degree d in the n variables x1, …, xn of grading 1. The present article investigates
the hit problem for the [Ascr ]-submodule of symmetric polynomials B(n) = P(n)[sum ]n , where
[sum ]n denotes the symmetric group on n letters acting on the right of P(n). Among the
main results is the symmetric version of the well-known Peterson conjecture. For a
positive integer d, let μ(d) denote the smallest value of k for which d = [sum ]ki=1(2λi−1), where λi [ges ] 0.
Disorder effects on dielectric response of Si irradiated with Ar+
Authors: Tripura Sundari S.
Published: October 2002

Irradiation induced changes in the complex dielectric spectra of single crystal Si are investigated with spectroscopic ellipsometry. The analysis of microstructural variations resulting from ion irradiation is carried out to establish the existence of a well defined amorphization threshold. Increase in fluence leads to amorphization of the crystal resulting in an order–disorder transition as inferred from peak to peak height of the first derivative spectra. The amorphous volume fraction deduced from a microstructure model using effective medium approximation is found to have a power law behavior. The variations in the critical point (CP) structure in the energy range 1.5 to 5 eV is studied as a function of fluence ranging from 6×1013 to 1×1017 Ar+ ions cm−2. The changes in the nature of the CPs is examined in detail by line shape analysis of the second derivative of the optical spectra above and below the amorphization threshold. Irradiation induced structural disorder and its effect on the interband optical transition, particularly the E1 critical point at 3.4 eV is analyzed in detail. The E1 structure is fitted in the complete fluence range with a 2D CP line shape with a large excitonic phase angle. A red shift of the E1 critical point, decrease in its amplitude, increase in excitonic phase angle and broadening of the line shape are observed with increasing fluence. All these parameters of the E1 CP show distinct behavior above and below the amorphization threshold.
Lightweight, space efficient low-pass radio-frequency interference filter modules for bolometric detectors
Authors: Leong J. R. , Bhatia R. S. , Hristov V. V. , Keating B. G. , Lange A. E. , Philhour B. J.
Published: October 2002

Extremely lightweight and space efficient low-pass radio-frequency interference (RFI) filter modules have been developed and tested for use with bolometric detectors. These filters are based on the compactness of a surface mount electro-magnetic interference chip filter. We have produced densely packed modules containing 21 filtered lines, which weigh 60 g, with dimensions of 38×36×11 mm. These modules provide greater than 20 dB attenuation over the entire frequency range tested (50 MHz–10 GHz) while providing over 60 dB attenuation for frequencies greater than 4.5 GHz. The filters suppress rf voltage noise and prevent radiation from RFI on the lines from entering the detector environment and heating up the bolometers. Modules have been used on bolometric detector systems containing as many as 16 RFI filtered bolometers.
Wetting in ternary mixtures—with and without amphiphiles
Authors: Schilling T. , Gompper G.
Published: October 2002

The interfacial wetting behavior of ternary fluid mixtures is investigated, both for systems where all components have isotropic interaction potentials, as well as for systems where one component is an amphiphile. The BEG model and the corresponding two-order-parameter Ginzburg–Landau model are employed for systems without amphiphiles. We calculate the global wetting phase diagram for nonamphiphilic mixtures. In the investigated range of interaction parameters, the wetting transitions are always continuous at three-phase coexistence. The critical behavior is found to be universal in some, nonuniversal in other parts of the phase diagram. For systems with amphiphiles, two additional interaction terms are taken into account. The first models the aggregation of amphiphilic molecules at the air–water interface, the second the formation of amphiphilic bilayers in water. We find that the first term leads to a reduction of the tension of the air–water interface, and favors wetting by the water-rich phase, while the second—bilayer—term leads to a reduction of the tension of the interface between the water-rich and amphiphile-rich phases.
A constant-velocity Mössbauer spectrometer with controlled temperature sweep
Authors: Veiga A. , Martı́nez N. , Mayosky M. , Spinelli E. , Zélis P. Mendoza , Pasquevich G. , Sánchez F. H.
Published: October 2002

A constant-velocity Mössbauer spectrometer with controlled temperature sweep of the sample is presented. The equipment was developed for Mössbauer thermal scanning experiments, allowing the determination of the evolution of the magnetic hyperfine field with temperature. It is based in a three level architecture implemented in a medium sized personal computer (PC). The instrument runs the widely used Linux operating system, supporting several custom microprocessor-based boards, extending the hardware capabilities of the PC. This scheme optimizes the required time for the experiment, exploiting in the background the full capabilities of modern multitasking operating systems in terms of networking, graphical user interfaces, and data storage. The prototype was tested applying the method to the simplest case, i.e., a symmetric sextet collapsing into a singlet. It was found that required times are an order of magnitude smaller than those demanded by the conventional methodology. The results obtained for the Fe57 temperature hyperfine field dependence are in good agreement with those obtained by conventional Mössbauer spectroscopy. More complex situations must be explored both experimentally and theoretically. It must be mentioned that the presented layout is actually a general tool for automation of experiments at a relative low cost.
Low-frequency noise and current–voltage characteristics of Schottky barrier contacts in a wide temperature range
Authors: Bozhkov V. G. , Kuzyakov D. Ju.
Published: October 2002

The low-frequency (1/f) noise and current–voltage characteristics of GaAs and Si Schottky barrier diodes are studied over a wide temperature range: 77–400 K. The peculiarities of temperature and current dependences of the spectral intensity (SI) of current fluctuations Si(I,T) (a specific increase of the SI with decrease in temperature and a deviation from a quadratic dependence of the Si–I2 form) are explained adequately by the influence of a predominantly local barrier height lowering at a Schottky barrier contact (SBC), most likely at its periphery. The Gaussian barrier height distribution at SBCs does not explain these peculiarities. It is shown that the 1/f noise at SBCs approaches the “ideal” noise of the Si–Iβ/fα form, where β=2 and α=1, as the temperature increases. The explanation for the “low-temperature anomaly” in SBCs [an increase in the ideality factor n and a decrease in the measured (from a saturation current) barrier height φbm with decrease in temperature, a weak variation of their product φbn≡nφbm in this case, and the character of the temperature dependence n(T) in the form of n≅1+T0/T (“T0 effect”)] is presented. This explanation is based on a fundamental property of real SBCs—the nonlinear bias dependence of the barrier height resulting in a growth of the ideality factor with a bias voltage (current) increase. The other necessary condition for revealing the “low-temperature anomaly” is the inclusion in theory of the fact that the n and φbm measurements are performed at the same current for all temperatures. An expression for the flatband barrier height φbf is derived. It takes into account the nonlinear bias dependence of the barrier height and the n(I) dependence which follows from it. On the basis of this expression the conditions are defined at which a simple approximation for φbf is valid: φbf≅φbn≡nφbm.
Time-dependent wave packet dynamics of the H+HLi reactive scattering
Authors: Padmanaban R. , Mahapatra S.
Published: October 2002

We report the initial-state-selected and energy-resolved total reaction probabilities for the H+HLi system calculated with the aid of a time-dependent wave packet approach. The ab initio potential energy surface (PES) of Dunne et al. [Chem. Phys. Lett. 336, 1 (2001)] is employed for the purpose. The reaction probabilities are reported for both the collinear and the three-dimensional arrangements of the reacting system. In the collinear arrangement the exothermic reaction path H+HLi→H2+Li is investigated only, whereas in the three-dimensional arrangement both competing reaction paths are investigated and the channel specific reaction probabilities are reported. The hydrogen exchange channel, in general, is found to be more favored over the LiH depletion channel. Both the collinear and the three-dimensional reaction probabilities reveal that the scattering occurs via resonance formation at low energies and the dynamics follows a more direct path at high energies. The overall dynamical characteristics of the system are consistent with the absence of any barrier in the underlying PES. The effect of the rotationally and vibrationally excited reactant LiH molecule on the dynamics is discussed. The importance of the noncollinear configuration of the reacting system on the LiH depletion dynamics is also delineated.
Low voltage, low power, high performance type II current conveyor-based linear current electrometers
Authors: Rajput S. S. , Jamuar S. S.
Published: October 2002

Monolithic linear current electrometers in complementary metal–oxide–semiconductor technology using type II current conveyors for high frequency current measurements are proposed. The proposed electrometers can measure the input current from 100 pA to 1.0 μA and have bandwidth in excess of 30 MHz.
Differential phase-shifting interferometry for in situ surface characterization during solution growth of crystals
Authors: Booth Nicholas A. , Stanojev Boris , Chernov Alexander A. , Vekilov Peter G.
Published: October 2002

We have developed a phase-shifting interferometer for high-resolution in situ imaging of the interfacial morphology during the growth of fast-growing crystals from solution. We demonstrate that the evolution of the surface morphology can be captured as the height distribution over surface areas as large as 2×2 mm2 with a depth resolution of 3 nm and a lateral resolution down to 0.5 μm with a frequency of 10–12 surface images per second. We describe the five image phase-shifting algorithm and subsequent processing, which quantify the surface morphology and yield the height differences between surface features. We illustrate the application of the technique to the (101) face of potassium di-hydrogen phosphate crystals. We visualize and monitor the formation of step bunches on the surface of this crystal during growth.
Imaging transport current distribution in high temperature superconductors using room temperature scanning laser microscope
Authors: Klein B. E. , Seo S. , Kwon C. , Park B. H. , Jia Q. X.
Published: October 2002

We report the feasibility of room temperature scanning laser microscopy (RTSLM) for the study of high temperature superconducting films. RTSLM images from SmBa2Cu3O7 and YBa2Cu3O7 thin films show that the ac voltage response exists only in the section of the bridge where the transport current produces a voltage drop. A photolithographically defined 60 μm×60 μm void in a 300-μm-wide bridge was clearly visible in a RTSLM image giving the spatial resolution smaller than 60 μm. In addition, the void disturbs the transport current distribution beyond itself generating an elongated shape void of 64 μm×85 μm with the longer side along the direction of current flow in the RTSLM image. Our results indicate that the RTSLM is a useful tool for investigating the transport current distribution in high temperature superconductors.
The design and performance of an x-ray micro-focusing system using differentially deposited elliptical mirrors at the National Synchrotron Light Source
Authors: Ablett J. M. , Kao C. C. , Lunt A.
Published: October 2002

The National Synchrotron Light Source X13 straight section houses two insertion devices: a small-gap undulator (IVUN) and an elliptically polarized wiggler. The low vertical β function at the center of the straight section, where IVUN is located, produces an extremely small vertical source size [full width at half maximum (FWHM)=15.5 μm]. To take advantage of the small source size for a wide range of x-ray microbeam applications, a Kirkpatrick–Baez pair of 10 cm long elliptically figured mirrors, fabricated using a differential-deposition technique, was designed and implemented. A FWHM focused spot size of 3 μm (vertical) by 9 μm (horizontal) was achieved. The performance of this microfocusing system and selected applications are reported.
Structural, magnetic, and transport studies of La0.8MnO3 films
Authors: Qian Q. , Tyson T. A. , Dubourdieu C. , Bossak A. , Sénateur J. P. , Deleon M. , Bai J. , Bonfait G. , Maria J.
Published: October 2002

A study of the properties of La0.8MnO3 films of varying thickness was performed. Transport and magnetization measurements show that the ferromagnetic (metallic) volume fraction of the film varies from ∼ 1/4 for ultrathin 60  Å films to ∼ 1/2 for 1600  Å films. Multilength scale structural measurements reveal that near 300  Å, a transition from highly strained ultrathin films to relaxed bulk-like films occurs. The transition region is characterized by low surface roughness, high crystallite orientation, and broad d-spacing distributions.
First- and second-order Raman spectra of galena (PbS)
Authors: Smith Gregory D. , Firth Steven , Clark Robin J. H. , Cardona Manuel
Published: October 2002

Raman spectra of cleaved, millimeter-sized single crystals of mineral galena (PbS) have been measured between 100 and 1200 cm−1 over the temperature range 80 to 373 K. Three low wave number bands are observed which can be reconciled with the results of earlier reports. However, changes in the peak wave numbers and in the relative intensities of these bands in response to changes in temperature do not conform with previous assignments for the observed bands. Detailed assignments are proposed which are based on resonance Raman processes. The observed bands are assigned to forbidden longitudinal optical excitations, which are allowed under resonance conditions by a Fröhlich interaction mechanism, and two-phonon excitations.
Compression and caging of CD3Cl by H2O layers on Ru(001)
Authors: Lilach Y. , Asscher M.
Published: October 2002

The interaction of two similar coadsorbed dipolar molecules H2O and CD3Cl has been studied as a function of coverage over Ru(001) under ultra high vacuum conditions. The complementary techniques of temperature-programmed desorption mass spectrometry (ΔP-TPD) and work function change in a Δφ-TPD mode were employed. Adsorption of water on top of CD3Cl reveals two major trends: At submonolayer methyl chloride coverage, post-deposited water compresses the methyl chloride molecules and forces them to flip over to the methyl down configuration at the second layer, leading eventually to three-dimensional islands. This is indicated by both CD3Cl ΔP-TPD and differential work function [d(Δφ)/dT] data. Higher water coverage [θ(H2O)>1.2 bilayers (BL)] causes full detachment of the CD3Cl molecules from the ruthenium surface, to be encapsulated within the amorphous solid water (ASW) layer that is formed. At even higher water coverage [θ(H2O)>5 BL], methyl chloride desorbs in an explosivelike mode at 165 K. The caged methyl chloride molecules lack any permanent dipole moment as indicated from differential Δφ-TPD analysis, explained in terms of a high level of disorder within the ASW. The relevance of the hydrophobic caging process to clathrate-hydrate formation is discussed.
From nematic emulsions to polymer dispersed liquid crystals
Authors: Lanzo J. , Nicoletta F. P. , De Filpo G. , Chidichimo G.
Published: October 2002

Nematic emulsions and polymer dispersed liquid crystals (PDLCs) are composite materials formed by micron-sized droplets of mesogenic molecules, which are embedded in fluid or solid matrices, respectively. Both systems can be switched from an opaque to a trasparent state by application of a suitable electric field. The main differences reside in the switching field and relaxation time values. Polymer dispersed liquid crystal films are generally characterized by higher switching fields and faster relaxation times. On the contrary, nematic emulsions show lower switching fields and longer decay times. Recently, we have obtained PDLC films by photopolymerization of nematic emulsions. Such films keep the advantages of conventional PDLCs, but have the opportunity of a finer control of liquid crystal droplet size. In this article we have focused our attention to the polymerization process, which converts nematic emulsions in polymer dispersed liquid crystals. In particular, we have investigated the electro-optical changes induced in nematic emulsions by the polymerization of the fluid matrix as a function of the irradiation time. A progressive increase in the switching fields is observed, while the decay times decrease in a significant way. Such results can be explained by assuming a decrease of liquid crystal droplet viscosity and an increase of boundary restoring forces acting on liquid crystal due to the polymerization process.