bluuebunny/crossref_metadata_2025 huggingface dataset:
Population Pharmacokinetic-Pharmacodynamic Model for Neutropenia with Patient Subgroup Identification: Comparison across Anticancer Drugs
Authors: Kloft Charlotte , Wallin Johan , Henningsson Anja , Chatelut Etienne , Karlsson Mats O.
Published: September 2006

Purpose: Cancer chemotherapy, although based on body surface area, often causes unpredictable myelosuppression, especially severe neutropenia. The aim of this study was to evaluate qualitatively and quantitatively the influence of patient-specific characteristics on the neutrophil concentration-time course, to identify patient subgroups, and to compare covariates on system-related pharmacodynamic variable between drugs.

Experimental Design: Drug and neutrophil concentration, demographic, and clinical chemistry data of several trials with docetaxel (637 patients), paclitaxel (45 patients), etoposide (71 patients), or topotecan (191 patients) were included in the covariate analysis of a physiology-based pharmacokinetic-pharmacodynamic neutropenia model. Comparisons of covariate relations across drugs were made.

Results: A population model incorporating four to five relevant patient factors for each drug to explain variability in the degree and duration of neutropenia has been developed. Sex, previous anticancer therapy, performance status, height, binding partners, or liver enzymes influenced system-related variables and α1-acid glycoprotein, albumin, bilirubin, concomitant cytotoxic agents, or administration route changed drug-specific variables. Overall, female and pretreated patients had a lower baseline neutrophil concentration. Across-drug comparison revealed that several covariates (e.g., age) had minor (clinically irrelevant) influences but consistently shifted the pharmacodynamic variable in the same direction.

Conclusions: These mechanistic models, including patient characteristics that influence drug-specific parameters, form the rationale basis for more tailored dosing of individual patients or subgroups to minimize the risk of infection and thus might contribute to a more successful therapy. In addition, nonsignificant or clinically irrelevant relations on system-related parameters suggest that these covariates could be negligible in clinical trails and daily use.
Genetics and Congenital Malformations: Interpretations, Attitudes and Practices in Suburban Communities and the Shamans of Ecuador
Authors: Paz-y-Miño César , Sánchez María Eugenia , Sarmiento Isabel , Leone Paola E.
Published: September 2006

Objetives: The purpose of the present article was to evaluate how shamans and the suburban communities of Quito interpret the terminology used in genetics. Methods: One hundred people living in 5 suburban districts of Quito were surveyed as well as 19 shamans of the Salasaca community. Results: The results show that members of both groups are little informed about genetics. As knowledge about genetics is correlated to educational level, which is very poor in both groups, knowledge and understanding of genetics are either very basic or nonexistent. As for the medical practices in treating genetic alterations, the surveys show that while in very severe cases scientific medicine is sought, in most cases explanations and a cure are given by shamanic medicine. Conclusion: There is limited knowledge of genetics and its terminology in the study population. Shamanic and marginal health practices seem to remain prevalent in these communities due to their low costs, the personal attention the individuals receive, and the holistic point of view employed. It is important that the community councils, the medical doctors and the shamans work together to set up community programs on medical education, particularly on genetics.
Left Ventricular Diastolic Dysfunction Is Related to Oxidative Stress and Exercise Capacity in Hypertensive Patients with Preserved Systolic Function
Authors: Dekleva Milica , Celic Vera , Kostic Nada , Pencic Biljana , Ivanovic Ana M. , Caparevic Zorica
Published: September 2006

Background: Left ventricular diastolic dysfunction and oxidative stress are important determinants in heart failure development. Peak oxygen uptake, maximal oxygen consumption, metabolic equivalents (MET), ventilatory response and time to respiratory gas exchange assess cardiopulmonary capacity. Aim: It was the aim of this study to investigate the impact of oxidative stress on diastolic indexes and cardiopulmonary exercise capacity in hypertensive patients with left ventricular diastolic dysfunction. Methods: Mitral flow velocities (E, A), ejection fraction, left atrial and ventricular diameters were assessed by Doppler echocardiography. Superoxide dismutase (SOD) and glutathione peroxidase activity in blood were evaluated. Sixty patients (aged 49.8 ± 9.2 years) with essential hypertension and preserved systolic function (ejection fraction 58.3 ± 7%) performed a bicycle exercise test. Forty patients showed impaired left ventricular relaxation (E/A <1, deceleration time of E >220 ms) and were assigned to group 1, while 20 had normal relaxation (group 2). Results: An increase in SOD was significantly blunted after exercise in group 1 compared with group 2 (p = 0.049). A significant difference between groups in the glutathione peroxidase level was observed before exercise (p = 0.038). There were significantly lower values of peak oxygen uptake and MET (p = 0.013 and p = 0.024, respectively) and a prolonged respiratory exchange ratio (p = 0.022) in group 1 compared with group 2. MET was significantly influenced by SOD level (p = 0.035). Conclusions: Lower antioxidative protection and impaired relaxation decrease cardiopulmonary capacity in hypertensive patients.
Environmental Cardiology
Authors: Bhatnagar Aruni
Published: September 2006

Environmental factors are considered key determinants of cardiovascular disease. Although lifestyle choices such as smoking, diet, and exercise are viewed as major environmental influences, the contribution of pollutants and environmental chemicals is less clear. Accumulating evidence suggests that exposure to pollutants and chemicals could elevate the risk of cardiovascular disease. Many epidemiological studies report that exposure to fine particles present in ambient air is associated with an increase in cardiovascular mortality. Statistically significant relationships between particulate air pollution and ischemic heart disease, arrhythmias, and heart failure have been reported. Animal studies show that exposure to ambient air particles increases peripheral thrombosis and atherosclerotic lesion formation. Exposures to arsenic, lead, cadmium, pollutant gases, solvents, and pesticides have also been linked to increased incidence of cardiovascular disease. Mechanistically, these effects have been attributed to changes in the synthesis or reactivity of nitric oxide that may be caused by environmental oxidants or increased endogenous production of reactive oxygen species. Additional studies are urgently needed to: identify the contribution of individual pollutants to specific aspects of cardiovascular disease; establish causality; elucidate the underlying physiological and molecular mechanisms; estimate the relative susceptibility of diseased and healthy individuals and that of specific population groups; and determine whether pollutant exposure are risk correlates, that is, whether they influence major risk factors, such as hypertension, cholesterol, or diabetes, or whether they contribute to the absolute risk of heart disease. Collectively, these investigations could contribute to the emergent field of environmental cardiology.
The Spike-Triggered Average of the Integrate-and-Fire Cell Driven by Gaussian White Noise
Authors: Paninski Liam
Published: September 2006

We compute the exact spike-triggered average (STA) of the voltage for the nonleaky integrate-and-fire (IF) cell in continuous time, driven by gaussian white noise. The computation is based on techniques from the theory of renewal processes and continuous-time hidden Markov processes (e.g., the backward and forward Fokker-Planck partial differential equations associated with first-passage time densities). From the STA voltage, it is straightforward to derive the STA input current. The theory also gives an explicit asymptotic approximation for the STA of the leaky IF cell, valid in the low-noise regime σ → 0. We consider both the STA and the conditional average voltage given an observed spike “doublet” event, that is, two spikes separated by some fixed period of silence. In each case, we find that the STA as a function of time-preceding-spike, τ, has a square root singularity as τ approaches zero from below and scales linearly with the scale of injected noise current. We close by briefly examining the discrete-time case, where similar phenomena are observed.
A Maximum Likelihood Approach to Density Estimation with Semidefinite Programming
Authors: Fushiki Tadayoshi , Horiuchi Shingo , Tsuchiya Takashi
Published: September 2006

Density estimation plays an important and fundamental role in pattern recognition, machine learning, and statistics. In this article, we develop a parametric approach to univariate (or low-dimensional) density estimation based on semidefinite programming (SDP). Our density model is expressed as the product of a nonnegative polynomial and a base density such as normal distribution, exponential distribution, and uniform distribution. When the base density is specified, the maximum likelihood estimation of the polynomial is formulated as a variant of SDP that is solved in polynomial timewith the interior point methods. Since the base density typically contains just one or two parameters, computation of the maximum likelihood estimate reduces to a one- or two-dimensional easy optimization problem with this use of SDP. Thus, the rigorous maximum likelihood estimate can be computed in our approach. Furthermore, such conditions as symmetry and unimodality of the density function can be easily handled within this framework. AIC is used to choose the best model. Through applications to several instances, we demonstrate flexibility of the model and performance of the proposed procedure. Combination with amixture approach is also presented. The proposed approach has possible other applications beyond density estimation. This point is clarified through an application to the maximum likelihood estimation of the intensity function of a nonstationary Poisson process.
The genus Trophomera Rubtsov & Platonova, 1974 with description of T. litoralis sp. n. (Nematoda: Benthimermithidae) from the tidal zone of the Kuril Archipelago and proposal of Benthimermis Petter, 1980 as a junior synonym
Authors: Miljutin Dmitry M.
Published: September 2006

The type species of Trophomera, T. iturupiensis, is redescribed from type
material and important errors in the original description corrected. As a
result of this emended description, Benthimermis is proposed as a junior
synonym of Trophomera and its species transferred accordingly. The family
name Benthimermithidae is retained according to articles 23.1 and 40.1 of
the International Code of Zoological Nomenclature. Trophomera is diagnosed
and an annotated list of nominal species presented. Trophomera litoralis sp.
n., collected from the tidal zone of Ushishir Island (Kuril Archipelago), is
described on the basis of four males. The males of T. litoralis sp. n.
differ from those of other Trophomera species primarily by the much higher
number of precloacal supplementary organs (105-108 vs 2-68). Trophomera
litoralis sp. n. is most similar to T. regalis comb. n. yet differs by
shorter body length (5.8-9.3 vs 14.9 mm), body proportions (a = 67-107 vs
124.4; c = 61-97 vs 135.7), greater length of the intermediate spermatoduct
between the anterior and posterior testes (ca 1/7th vs ca 1/140th of body
length), tail shape (rounded conoid vs pointed conoid), and number of
precloacal supplementary organs (105-108 vs 49).
The Interaction of Clouds and Dry Air in the Eastern Tropical Pacific
Authors: Zuidema Paquita , Mapes Brian , Lin Jialin , Fairall Chris , Wick Gary
Published: September 2006

Cloud radar observations of eastern Pacific intertropical convergence zone cloud vertical structure are interpreted in light of soundings, 100-km-scale divergence profiles calculated from precipitation radar Doppler velocities, and surface rain gauge data, from a ship at 10°N, 95°W during the 2001 East Pacific Investigation of Climate (EPIC) experiment. The transition from convective to stratiform rain is clear in all four datasets, indicating a coherence from local to 100-km scale. A novel finding is dry air intrusions at altitudes of 6–8 km, often undercutting upper-level ice clouds. Two distinct dry air source regions are identified. One is a relatively dry area overlying the cooler waters of the Costa Rica oceanic thermocline dome, centered approximately 400 km east-northeast of the ship site. The other is the even drier near-equatorial subsidence zone south of 6°–7°N. The former source is somewhat peculiar to this specific ship location, so that the ship sample is not entirely representative of the region.

The 20–25 September period is studied in detail, as it depicts two influences of the dry air on cloud vertical structure. One is the modulation of small-scale surface-based convection, evident as a weakening and narrowing of cloud radar reflectivity features. The other springs from intense sublimation cooling as differential advection brought snowing anvil clouds over the dry layers. During one half-day period of strong sublimation, the cooling rate is inferred to be several tens of degrees per day over a 100-hPa layer, based on a heat budget estimate at 100-km scale involving the horizontal wind divergence data. This is consistent with fluxing ice water contents of 0.05–0.10 g m−3 derived from the cloud radar reflectivities. The temperature profile shows the dynamically expected response to this cooling, a positive–negative–positive temperature anomaly pattern centered on the sublimating layer. A buoyancy-sorting diagnostic model of convection indicates that these upper-troposphere temperature anomalies can cause premature detrainment of updrafts into the lower part of the cloudy layer, a feedback that may actively maintain these long-lasting dense anvils.

Middle-troposphere southerly dry air inflow is also evident in large-scale analysis. Given the proximity of the dry equatorial subsidence zone to the eastern tropical Pacific, the differential advection of dry and cloudy air, the ensuing sublimation, and its dynamical aftereffects may play a role in establishing the region’s climate, although the extent of their significance needs to be further established.
Coupled Ocean–Atmosphere–Ice Response to Variations in the Southern Annular Mode
Authors: Sen Gupta Alexander , England Matthew H.
Published: September 2006

The coupled ocean–atmosphere–ice response to variations in the Southern Annular Mode (SAM) is examined in the National Center for Atmospheric Research (NCAR) Community Coupled Climate Model (version 2). The model shows considerable skill in capturing the predominantly zonally symmetric SAM while regional deviations between model and observation SAM winds go a long way in explaining the generally small differences between simulated and observed SAM responses in the ocean and sea ice systems. Vacillations in the position and strength of the circumpolar winds and the ensuing variations in advection of heat and moisture result in a dynamic and thermodynamic forcing of the ocean and sea ice. Both meridional and zonal components of ocean circulation are modified through Ekman transport, which in turn leads to anomalous surface convergences and divergences that strongly affect the meridional overturning circulation and potentially the pathways of intermediate water ventilation. A heat budget analysis demonstrates a conspiring of oceanic meridional heat advection, surface heat fluxes, and changes in mixed layer depth, which acts in phase to imprint a strong circumpolar SAM signature onto sea surface temperatures (SSTs), while other oceanic processes, including vertical advection, are shown to play only a minor role in contrast to previous suggestions. Lagged correlations show that although the SAM is mainly controlled by internal atmospheric mechanisms, the thermal inertia of the ocean reimprints the SAM signature back onto surface air temperatures (SATs) on time scales longer than the initial atmospheric signal. Sea ice variability is well explained by a combination of atmospheric and oceanic dynamic and thermodynamic forcing, and by an albedo feedback mechanism that allows ice extent anomalies to persist for many months. Nonzonally symmetric components of the SAM winds, particularly in the region surrounding the Antarctic Peninsula, have important effects for other climate variables.
Simulated Global-Mean Sea Level Changes over the Last Half-Millennium
Authors: Gregory J. M. , Lowe J. A. , Tett S. F. B.
Published: September 2006

Simulations of the last 500 yr carried out using the Third Hadley Centre Coupled Ocean–Atmosphere GCM (HadCM3) with anthropogenic and natural (solar and volcanic) forcings have been analyzed. Global-mean surface temperature change during the twentieth century is well reproduced. Simulated contributions to global-mean sea level rise during recent decades due to thermal expansion (the largest term) and to mass loss from glaciers and ice caps agree within uncertainties with observational estimates of these terms, but their sum falls short of the observed rate of sea level rise. This discrepancy has been discussed by previous authors; a completely satisfactory explanation of twentieth-century sea level rise is lacking. The model suggests that the apparent onset of sea level rise and glacier retreat during the first part of the nineteenth century was due to natural forcing. The rate of sea level rise was larger during the twentieth century than during the previous centuries because of anthropogenic forcing, but decreasing natural forcing during the second half of the twentieth century tended to offset the anthropogenic acceleration in the rate. Volcanic eruptions cause rapid falls in sea level, followed by recovery over several decades. The model shows substantially less decadal variability in sea level and its thermal expansion component than twentieth-century observations indicate, either because it does not generate sufficient ocean internal variability, or because the observational analyses overestimate the variability.
Bottom Layer Turbulence in the Red Sea Outflow Plume
Authors: Peters Hartmut , Johns William E.
Published: September 2006

Turbulence in the Red Sea outflow plume in the western Gulf of Aden was observed with an upward-looking, five-beam, 600-kHz acoustic Doppler current profiler (ADCP). The “Bottom Lander” ADCP was deployed on the seafloor in two narrow, topographically confined outflow channels south of Bab el Mandeb for periods of 18–40 h at three locations at 376-, 496-, and 772-m depths. Two deployments were taken during the winter season of maximum outflow from the Red Sea and two in the summer season of minimum outflow. These short-term observations exhibit red velocity spectra with high-frequency fluctuations of typically a few centimeters per second RMS velocity during strong plume flow as well as strong subtidal variations. In one winter season event, the plume flow was reduced by a factor of 4 over an 18-h time span. In variance-preserving form, velocity spectra show a separation at frequencies of 0.3–3 cycles per hour between low-frequency and high-frequency signals. The latter show significant coherence between horizontal and vertical velocity components; hence they carried turbulent stress. Based on a comparison with velocity spectra from atmospheric mixed-layer observations, the authors argue that large variance at frequencies of the order of 1 cph was possibly associated with bottom-generated, upward-propagating internal waves. One coherent feature that matched such waves was observed directly. Higher frequencies correspond to turbulent motions of energy-carrying scales. The turbulent Reynolds stress at heights above the bottom between 4 and 30–40 m was computed for most of the ADCP observations. Near the bottom, the streamwise turbulent stress and the streamwise velocity followed a quadratic drag law with drag coefficients ranging from 0.002 to 0.008. There was also significant spanwise stress, hinting at the three-dimensional nature of the boundary layer flow. The time–height variations of the stress and its spectrum proved to be complex, one of its most striking features being angles of up to ∼40° between the direction of the stress and that of the low-frequency flow. The turbulent shear production and eddy viscosity were also examined. On the technical side, the paper discusses the role of the fifth, center-beam velocity measurements in correcting for instrument tilt along with the effect of beam spreading in the 30° Janus configuration of the “regular” four ADCP beams. Instrumental noise and detection limits for the stress are also established.
Special Section: Contemporary Clinical Challenges of Group Analysis Group Analysis
Authors: Nitzgen Dieter
Published: September 2006

This paper presents a general overview of the challenges which the practice of group analysis continues to face in the field of clinical research, highlighting some of the social changes and economic pressures which influence and affect these challenges. Economic constraints are highlighted, with some suggestions as to how group analysis can develop in order to endeavour to meet the needs of different types of patients, as well as satisfying the ever-changing demands of health services and organizations.
An Investigation on Woven-glass Fiber-reinforced Epoxy Laminate Conveyor Chain Components
Authors: Demirsoy Mine , Özes Çicek
Published: September 2006

This article is concerned with the experimental and numerical results of the stress analysis in woven-glass fiber-reinforced conveying chain components. The effects of various loading conditions on the stress of a pin-loaded composite component are investigated. For the experimental study, an apparatus had been developed to simulate chain components in real motion, and two different loading conditions of the chain component have been investigated. The first condition represents the movement of the chain components without loading, while in the second condition, the chain component tand moves the load. The finite element code ANSYS has been used to perform the numerical analysis using three-dimensional eight-noded layered structural solid elements. The chain tensile forces loaded through pins are chosen to be 300, 600, 900, and 1200 N for the two conditions of the chain components. Comparisons are made between the numerical and the experimental studies for the two different conditions. The experimental and numerical results show that at the second loading condition the stress values increase by increasing the tensile force.
Exploring the Meaning of Motivation Across Cultures: IRT Analyses of the Goal Instability Scale
Authors: Casillas Alex , Schulz E. Matthew , Robbins Steven B. , Santos Paulo Jorge , Lee Richard M.
Published: September 2006

The present study uses item response theory (IRT) to establish comparability between the English and Portuguese versions of the Goal Instability Scale (GIS), a measure of generalized motivation. A total of 2,848 American and 679 Portuguese high school students were administered their respective language versions of the GIS. Results showed only minor differences in item performance between language versions, suggesting equivalent measurement of the underlying motivational construct. Implications regarding the interpretation of IRT analyses for intervention purposes, as well as future research, are discussed.
Computer-Based Career Exploration: Usage Patterns and a Typology of Users
Authors: Gore Paul A. , Bobek Becky L. , Robbins Steven B. , Shayne Leslie
Published: September 2006

This study describes the career exploratory behaviors of high school and college students and offers a typology of users of a Web-delivered computer career guidance application. Access to the records of 87,293 high school and college students allowed for the identification and replication of three emergent types of users: a general browser, a focused user, and an in-depth user. Exit surveys of subsequent career exploratory behavior outside of the web application for a subset of users ( n = 1655) helped to clarify differences in exploration by user type, with in-depth and focused users more likely to seek additional information and to talk with others about their career decisions. Our findings reinforce the importance of focusing student behavior during Web-based guidance and have implications for future research on the ecology of career exploration via the Web.
X-ray microtomography studies of localised corrosion and transitions to stress corrosion cracking
Authors: Connolly B. J. , Horner D. A. , Fox S. J. , Davenport A. J. , Padovani C. , Zhou S. , Turnbull A. , Preuss M. , Stevens N. P. , Marrow T. J. , Buffiere J.-Y. , Boller E. , Groso A. , Stampanoni M.
Published: September 2006

Two forms of high resolution X-ray tomographic experiments (i.e. synchrotron based X-ray microtomography and desktop microfocus computed X-ray tomography) are demonstrated in the present paper to illustrate the wide application of these techniques for qualitative and quantitative studies of localised corrosion and environmentally assisted cracking. Specifically, synchrotron based X-ray tomography was used to investigate the localised corrosion morphology within aluminium specimens when exposed in situ to a chloride environment while microfocus computed X-ray tomography was used to investigate the morphology and quantify the transition from localised corrosion to stress corrosion cracking in steel specimens exposed ex situ to a simulated corrosive condensate environment.
Influence of bias and in situ cleaning on through cage (TC) or active screen plasma nitrided (ASPN) steels
Authors: Hubbard P. , Dowey S. J. , Doyle E. D. , McCulloch D. G.
Published: September 2006

The effect of a substrate bias and prenitride plasma etching on the nitriding response of four steel substrates is investigated in a two factor two level full factorial experimental design. The steels investigated were P20 (M200, plastic mould steel), H13 (W302, hot work tool steel – as received), 4140 (preheat treated nitriding steel) and 1020 (CS1020, bright mild steel). The nitriding response was determined from surface and cross-sectional hardness measurements. Nitrogen depth profile measurements were obtained using glow discharge optical emission spectroscopy. Considering the main effects, the results show that without a worktable bias during the nitriding step there is effectively little or no nitriding response in most of the materials. The prenitride plasma etch did not produce a significant surface hardness response in all steels except H13, where a prior etch substantially increased surface hardness and influenced the hardness depth profile. The bias also significantly increased the nitrogen wt-%. The plasma etch also influenced the near surface nitrogen wt-% concentrations, however the practical implications of this require further investigation.
Kaolin and halloysite deposits of Brazil
Authors: Wilson I. R. , de Souza Santos H. , de Souza Santos P.
Published: September 2006

Brazil is a significant producer of kaolin with almost 2.5 Mt in 2005 representing 10% of the world's total of 25.0 Mt. Brazil is now the second largest producer in the world, after the USA, having overtaken the United Kingdom in 2005. The kaolin resources are widespread throughout the country and are varied in their origin, physical and chemical properties and morphology. The kaolin industry in Brazil has shown a dramatic rise over the last 15 years with production of beneficiated kaolin increasing from 0.66 Mt in 1990 to 2.5 Mt in 2005. The reason for the growth is solely the development of large kaolin deposits in the Amazon Basin that account for 90% of Brazil's production. In 2005 there are just two companies involved in the production and sales of kaolin from the Amazon Basin, namely Imerys (RCC — Rio Capim Caulim) and Caemi (a subsidiary of CVRD — Companhia Vale do Rio Doce) with kaolin operations of CADAM (Jari River) and PPSA (Capim River operations).
A method for determining the CEC and chemical composition of clays via XRF
Authors: Battaglia S. , Leoni L. , Sartori F.
Published: September 2006

A new method for determining the cation exchange capacity (CEC) of clays is proposed. The method is based on X-ray fluorescence analysis of natural and Ba-exchanged clays following the analytical procedure suggested by Franzini et al. (1975). This procedure, which utilizes powder pellets and is based on a full matrix correction method, is frequently applied in Earth Sciences laboratories for the routine analysis of minerals and rocks. For the analysis of Ba-exchanged clays, Franzini's procedure has been modified slightly to account for the contribution of Ba to matrix effects.

The new method, which furnishes both the CEC and the chemical compositions of the whole natural clay samples, has been tested on the eight ‘Source Clays’ of The Clay Minerals Society. The results compare well with data reported in the literature and confirm the accuracy and precision of the method and make it a valid alternative to techniques based on wet chemistry, execution of which is usually more time-consuming and which often requires greater analytical skill.
Clay minerals as dynamic tracers of suspended matter dispersal in the Gulf of Cadiz (SW Spain)
Authors: Gutiérrez-Mas J. M. , López-Aguayo F. , Achab M.
Published: September 2006

The dispersal of suspended matter in the Gulf of Cadiz (SW Spain) is related to its geographical position near the Strait of Gibraltar, and the continental margin, and to Atlantic and Mediterranean water flows and their interaction with the littoral tidal processes. The main direction for transport of suspended matter is towards the southeast, along the continental margin, from the mouths of the rivers Guadiana and Guadalquivir to the Mediterranean. This general transport pattern is perturbed by littoral processes such as those occurring in Cadiz Bay, where a portion of Atlantic suspended matter, driven by flood tide, comes into the inner bay and is deposited in the shallow waters of lagoons and salt marshes. Subsequently, because of the southeast wind and waves, these sediments are remobilized and transported to the west by the ebb tide, to deeper Atlantic waters. This dynamic interaction between Atlantic and littoral waters generates a different type of sediment layout, the origin of which is difficult to establish.

In order to understand the dispersal of the suspended matter and its effects on the inner continental shelf, the distribution of the main clay minerals has been determined by means of X-ray and Q-mode and R-mode factor analysis. The suspended matter dispersal paths were established through the distribution of main clay mineral associations and from the ratios amongst these minerals. The results allow us to determine the importance of the tidal flows in the suspended matter transport system of the Gulf of Cadiz. Therefore, a record was kept of which of the outgoing tidal flows from the inner parts of Cadiz Bay reached the continental shelf. The flows intercept the clear Atlantic waters giving rise to a complex sediment distribution and to the mix of clay minerals. The study has also allowed us to establish the sediment source areas and the extent of sediment transport and the paths they follow.
Forms of K as a function of clay mineralogy and soil development
Authors: Nabiollahy K. , Khormali F. , Bazargan K. , Ayoubi SH.
Published: September 2006

The relationships between different pools of K, i.e. exchangeable, HN03-extractable, mineral and total, were investigated as a function of clay mineralogy and soil development in soils of Kharkeh Research Station, Kurdestan Province, western Iran. Samples from different horizons often pedons were selected and analysed for clay mineralogy and K fractionation. X-ray diffraction patterns revealed that clay minerals in the soils studied were similar in type, while their abundances were different. The smectite content was significantly greater in Vertisols than in the other soils. The results of K fractionation showed that mineral K and HN03-extractable K (exchangeable and nonexchangeable, respectively) and the clay content of the soils containing lesser illite (10–30%) were significantly different from those with more illite (30–50%). Moreover, the regression slopes between water-soluble and NE4OAc-extractable K were lower in soils with more smectite due mainly to the presence of larger specific surface areas for K sorption in smectitic soils. Based on soil evolution and different forms of K, the soils studied were grouped in two major categories: (1) Vertisols and (2) Entisols, Inceptisols and Mollisols. There were greater contents of all forms of K in Vertisols than in the other soil orders. This was mainly related to the greater clay content and the dominance of smectite in the clay fraction of Vertisols.
Diagenetic history of the Podhale-Orava Basin and the underlying Tatra sedimentary structural units (Western Carpathians): evidence from XRD and K-Ar of illite-smectite
Authors: Środoń J. , Kotarba M. , Biroň A. , Such P. , Clauer N. , Wójtowicz A.
Published: September 2006

Diagenesis in the Podhale and Orava Paleogene flysch basins and in the underlying Mesozoic structural units was studied by XRD measurement of the percent smectite in the mixedlayer illite-smectite from shales and K-Ar dating of the illite-smectite from bentonites, supported by XRD quantitative mineral analysis, grain density, and porosity measurements of the bulk shales. The diagenetic mineral reactions identified in the flysch shales include illitization of smectite (>60 to <5%S), dissolution of K-feldspar and kaolinite, crystallization of quartz, albite and chlorite. An unusually large amount of basin history information was obtained by combining the illite-smectite data from wells and from the present erosional surface of the basin.

The rocks underwent burial diagenesis at a stable geothermal gradient similar to the present-day value of 21±2°C/km. The maximum burial temperatures were reached very quickly (high sedimentation rate) close to the basin inversion time, at ∼17 Ma in the western part and 18 Ma in the eastern part.

The basin floor, which included the present-day Tatra Mts., was inclined towards the East. The thickness of the sedimentary filling of the basin ranged from 3.5–4.5 km in the western Tatra (removed entirely), to 5–6 km in the western Podhale (<3–4 km removed), to 6.5–7.5 km in the eastern Podhale (>4–5 km removed), and even more in the eastern Tatra and Spisská Magura close to the Ružbachy Fault. These data imply a major subsidence followed by uplift of the Podhale plus Tatra block along the Ružbachy Fault and the deposition of a thick sequence of Lower Miocene sediments over the entire area (latter removed by erosion).

The Mesozoic rocks of all the structural units underlying the flysch basin underwent advanced diagenesis (maximum palaeotemperatures of 160–270°C) during an Upper Cretaceous tectonic burial event at ∼80–90 Ma. The tectonic overload was removed before the Eocene transgression (49–42 Ma).
Microstructure and properties of stoneware clay bodies
Authors: Flynn A. J. , Stachurski Z. H.
Published: September 2006

Raw clay materials manufactured for stoneware use are typically compounds of kaolins, silicas and feldspars. Two stoneware clay materials examined here were chosen because each is representative of the range of manufactured clay bodies. Samples were fired in an oxidizing atmosphere to a range of temperatures between ∼1000 and 1300°C. Sample dimensions, density, porosity and mechanical properties under compression were measured as a function of firing temperature. Thin sections, showing particles and their relationship to pore/void structures, were prepared, recorded under scanning electron microscopy (SEM), and analysed. The observed changes in microstructure can be related to previously described metamorphic and micro-eutectic reactions and a gradual sintering process. Indications of changes to apparent porosity are further amplified by measured changes of mechanical properties. The modulus of elasticity increases with reduction in porosity to a point at which porosity ceases to be the principal determining factor. The critical Griffith's crack length, calculated from fracture-strength measurement, exhibits a similar trend. The onset of these changes coincides with a significant increase in sealed porosity and with the microstructural metamorphosis as revealed by SEM.
A novel electron paramagnetic resonance-based assay for prostaglandin H synthase-1 activity
Authors: Turnbull Catriona M , McClure Danny , Rossi Adriano G , Megson Ian L
Published: September 2006

Background

Prostaglandin H2 synthase (PGHS) is the enzyme that catalyses the two-stage conversion of arachidonic acid to prostaglandin H2 (PGH2) prior to formation of prostanoids that are important in inflammation. PGHS isozymes (-1 and -2) are the target for nonsteroidal anti-inflammatory drugs (NSAIDs).

Given the rekindled interest in specific anti-inflammatory PGHS inhibitors with reduced unwanted side effects, it is of paramount importance that there are reliable and efficient techniques to test new inhibitors. Here, we describe a novel in vitro electron paramagnetic resonance (EPR)-based assay for measuring the activity of PGHS-1.

Methods

We validated a novel in vitro PGHS-1 activity assay based on the oxidation of spin-trap agent, 1-hydroxy-3-carboxy-pyrrolidine (CPH) to 3-carboxy-proxy (CP) under the action of the peroxidase element of PGHS-1. This quantifiable spin-adduct, CP, yields a characteristic 3-line electron paramagnetic (EPR) spectrum.

Results

The assay is simple, reproducible and facilitates rapid screening of inhibitors of PGHS-1. Aspirin (100 μM, 1 mM) caused significant inhibition of spin-adduct formation (72 ± 11 and 100 ± 16% inhibition of control respectively; P < 0.05). Indomethacin (100 μM) also abolished the signal (114 ± 10% inhibition of control; P < 0.01). SA and the PGHS-2-selective inhibitor, NS398, failed to significantly inhibit spin-adduct generation (P > 0.05).

Conclusion

We have demonstrated and validated a simple, reproducible, quick and specific assay for detecting PGHS-1 activity and inhibition. The EPR-based assay described represents a novel approach to measuring PGHS activity and provides a viable and competitive alternative to existing assays.
The influence on the immunomodulatory effects of dying and dead cells of Annexin V
Authors: Munoz Luis E , Franz Sandra , Pausch Friederike , Fürnrohr Barbara , Sheriff Ahmed , Vogt Birgit , Kern Peter M , Baum Wolfgang , Stach Christian , Von Laer Dorothee , Brachvogel Bent , Poschl Ernst , Herrmann Martin , Gaipl Udo S
Published: September 2006

Apoptotic and necrotic cells expose phosphatidylserine (PS). This membrane modification ensures a swift recognition and uptake by phagocytes of the dying and dead cells. Annexin V (AxV) preferentially binds to anionic phospholipids and thereby, modulates the clearance process. First, we analyzed the influence of AxV on the immunogenicity of apoptotic cells. The addition to apoptotic cells of AxV prior to their injection into mice increased their immunogenicity significantly. Next, we studied the influence of endogenous AxV on the allogeneic reaction against apoptotic and necrotic cells. To preserve heat-labile, short-lived “danger signals,” we induced necrosis by mechanical stress. Wild-type mice showed a strong, allogeneic delayed-type hypersensitivity (DTH) reaction. In contrast, AxV-deficient animals showed almost no allogeneic DTH reaction, indicating that endogenous AxV increases the immune response against dead cells. Furthermore, AxV-deficient macrophages had a higher immunosuppressive potential in vitro. Next, we analyzed the influence of AxV on chronic macrophage infection with HIV-1, known to expose PS on its surface. The infectivity in human macrophages of HIV-1 was reduced significantly in the presence of AxV. Finally, we show that AxV also blocked the in vitro uptake by macrophages of primary necrotic cells. Similar to apoptotic cells, necrotic cells generated by heat treatment displayed an anti-inflammatory activity. In contrast, mechanical stress-induced necrotic cells led to a decreased secretion of IL-10, indicating a more inflammatory potent-ial. From the experiments presented above, we conclude that AxV influences the clearance of several PS-exposing particles such as viruses, dying, and dead cells.
Analysis of microdiffuser/nozzles
Authors: Yang K-S , Liu M-S , Chen I-Y , Wang C-C
Published: September 2006

In this study, an analysis of the performance of micronozzle/diffusers is performed and fabrication of the micronozzle/diffuser is conducted and tested. It is found that the ratio of the loss coefficient of nozzle and diffuser increases with the Reynolds number and with the opening angle. At a given Reynolds number, the pressure loss coefficient for nozzle is higher than that of the diffuser due to considerable difference in the momentum change. At a fixed volumetric flowrate, a ‘minimum’ phenomenon of the pressure loss coefficient versus nozzle/diffuser depth is encountered. This is related to the interactions of velocity change and friction factor. Good agreements of the measured data with the predicted results are found in this study except at a diffuser having an opening angle of 20°. This is because of the presence of flow separation. The departure of this case to the prediction is due to the separation phenomenon in a larger angle of the diffuser. Hence, a more complicated two- and three-dimensional model is adopted to verify this flow separation inside the diffuser. For the simulation of the two-dimensional case, asymmetry flow field is seen for low Reynolds number region, whereas this phenomenon is not seen under three-dimensional simulation due to the confinement of the side wall.
Numerical calculation of centrifugal fan noise
Authors: Liu Q , Qi D , Mao Y
Published: September 2006

A numerical study on the aerodynamic noise generation of an industrial centrifugal fan with forward swept blades is carried out. Three-dimensional numerical simulations of the complete unsteady flowfield in the whole impeller — volute configuration are performed to obtain the aerodynamic sound sources. Then, aerodynamic sound is calculated using the Lowson equation and compared with the measurements. Moreover, the fan is modified for noise reduction by increasing the distance between the impeller tip and the volute tongue and sloping the volute tongue. The sound levels of the modified fan are lower than those of the original one over almost the entire range of frequencies analysed. The blade passing frequency level of the modified fan is decreased by about 15 dB at the design point. The method described and applied in this work provides a good qualitative prediction of the noise generation when designing a new fan, thus facilitating the choice of the lowest noise fan from several feasible alternatives.
Acridone-labeled Base-discriminating Fluorescence (BDF) Nucleoside: Synthesis and Their Photophysical Properties
Authors: Saito Yoshio , Hanawa Kazuo , Kawasaki Naomi , Bag Subhendu Sekhar , Saito Isao
Published: September 2006

Acridone-labeled BDF bases AcA and AcU were incorporated into oligonucleotides (ODNs) and their photophysical properties were evaluated. The BDF probe containing AcA is extremely powerful in recognizing opposite base T via enhancement of the fluorescence intensity. Furthermore, they emit strong fluorescence at a longer wavelength than previously reported pyrene-labeled BDF probes and thus can be used for the detection of SNPs.
Surgical procedure for implanting a radiotelemetry transmitter to monitor ECG, heart rate and body temperature in small Carassius auratus and Carassius auratus gibelio under laboratory conditions
Authors: Snelderwaard P Ch , van Ginneken V , Witte F , Voss H P , Kramer K
Published: September 2006

Radiotelemetry provides an alternative means of obtaining physiological measurements from conscious and freely moving animals, without introducing stress artefacts. A surgical procedure is described for implanting radiotelemetry transmitters to monitor the electrocardiogram (ECG), heart rate (HR) and body temperature (BT) in small goldfish ( Carassius auratus; 50–100 g) and Prussian carp ( Carassius auratus gibelio; 100 g). This type of transmitter is commonly implanted in freely moving mice. After surgery and a recovery period of 24 h, the ECG, HR and BT were recorded in freely swimming fish within the limitations of the aquarium.
Role of cage material, working style and hearing sensitivity in perception of animal care noise
Authors: Voipio H-M , Nevalainen T , Halonen P , Hakumäki M , Björk E
Published: September 2006

During daily care, laboratory animals are exposed to a variety of sounds which may have effects on welfare and also cause physiological and behavioural changes. So far, almost no attention has been paid to individual sounds or the sound level caused by animal care or the sound level inside the animal cage. In this study, sounds from selected rat care procedures were recorded: pulling cage out of the rack, placing it onto a table and replacing the cage back into the rack; with measurements made inside the rat cage and in the adjacent cage. Diet was poured into the food hopper and sounds were recorded inside the cage and also the adjacent cage. The work was repeated in a calm and also in a hurried style, using stainless steel and polycarbonate cages. Finally, the sounds produced by running tap water were recorded. Differences between rat and human hearing were compared using novel species-specific sound level weightings: R-weighting for rats dB(R) and H-weighting for human dB(H). Hurried work with steel caused sound exposure levels exceeding 90 dB(R) when the cages were placed into the rack and about 80 dB(R) when pulling them out of the rack or placing onto a table. With polycarbonate, the levels were 10–15 dB(R) lower. Unhurried calm working produced lower sound exposure levels than hurried working in many procedures. When the procedures were repeated with measurements in the adjacent cage, the sound exposure levels were lower, but the results were similar. Pouring food pellets into a hopper above the rat's head caused 15 dB(R) higher sound exposure levels than pouring food to an adjacent cage. In general, humans hear these sounds about 10–15 dB louder than rats. In conclusion, cage material, working style and hearing sensitivity all have an impact on the sound exposure level in the rodent cage. With correct working methods, high sound levels can be efficiently avoided in most cases.