bluuebunny/crossref_metadata_2025_split huggingface dataset:
Marine and human activity influences on the groundwater quality of southern Korinthos area (Greece)
Authors: Stamatis G. , Voudouris K. 
Published: August 2003

AbstractIn this paper the groundwater quality of the southern part of Korinthos region (north‐east Peloponnese) is discussed. The geology is characterized by a thick sequence of Neogene marls alternating with sandstones, overlain by superficial Quaternary deposits. The latter consist of a mixture of loose materials such as conglomerates, marly sandstones, sands and clay to silty sands. The area is crossed by a fault system parallel to the coastline, and the Quaternary sediments have formed extended Tyrrhenian marine terraces. Two aquifers have been identified in the area. The first is unconfined and occurs within the Quaternary sediments whereas the other is a deep confined aquifer occurring within the underlying Neogene marl series. Analysis of hydrochemical evolution over the past 30 years has indicated significant deterioration of quality owing to seawater intrusion and nitrate pollution. The various sources of pollution have rendered, to a large extent, shallow groundwater unsuitable not only for potable water supply but also for irrigation purposes. However, this is not the case for the deeper confined aquifer. Statistical analysis was used to explore the evolution of salinization during the years 1968 and 1998. In view of the alarming conditions caused by the documented groundwater quality deterioration, the need for integrated water resources management is stressed to maintain the socio‐economic growth of the region studied. Copyright © 2003 John Wiley & Sons, Ltd.
An effective approach to phase‐noise reduction for microwave sources
Authors: Xu Yansheng , Bosisio Renato G. 
Published: August 2003

AbstractIn this paper, a new method of phase‐noise reduction for microwave sources is proposed. The phase noise is reduced from a microwave signal generator or microwave oscillator without need of high‐Qcomponents. The output of the microwave source is compared with its delayed counterpart using a six‐port comparator. The detected phase‐difference signal is used to make corrections to the original microwave signal in order to reduce its phase variation due to noise effect. A schematic diagram of this approach is provided and its feasibility is tested by analysis and simulation. Analysis shows that the introduction of the six‐port comparator for phase‐noise reduction is very effective; a great amount of phase noise can be removed and the quality of the microwave signal is improved significantly. The implementation of this approach is also discussed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 36–39, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11119
Comparison of Automated and Manual Nucleic Acid Extraction Methods for Detection of Enterovirus RNA
Authors: Knepp Julia H. , Geahr Melissa A. , Forman Michael S. , Valsamakis Alexandra 
Published: August 2003

ABSTRACTAutomated nucleic acid extraction is an attractive alternative to labor-intensive manual methods. We compared two automated methods, the BioRobot M48 instrument (Qiagen, Inc.) and MagNA Pure (Roche Applied Sciences) methods, to two manual methods, the QIAamp Viral RNA Mini kit (Qiagen) and TRIzol (Invitrogen), for the extraction of enterovirus RNA. Analytical sensitivity was assessed by dilution analysis of poliovirus type 2 Sabin in cerebrospinal fluid. The sensitivity of PCR was equivalent after RNA extraction with QIAamp, BioRobot M48, and MagNA Pure. All 18 replicates of 100 PFU/ml were detected after extraction by the four methods. Fewer replicates of each successive dilution were detected after extraction by each method. At 10−1PFU/ml, 17 of 18 replicates were positive by QIAamp, 15 of 18 replicates were positive by BioRobot M48, and 12 of 18 replicates were positive by MagNA Pure; at 10−2PFU/ml, 4 of 17 replicates were positive by QIAamp, 2 of 18 replicates were positive by BioRobot M48, and 0 of 18 replicates were positive by MagNA Pure. At 10−3PFU/ml, no replicates were detected. Evaluation of TRIzol was discontinued after nine replicates due to a trend of lower sensitivity (at 10−3PFU/ml eight of nine replicates were positive at 100 PFU/ml, four of nine replicates were positive at 10−1PFU/ml, and zero of nine replicates were positive at 10−2PFU/ml). Concordant results were obtained in 24 of 28 clinical specimens after extraction by all methods. No evidence of contamination was observed after extraction by automated instruments. The data indicate that the sensitivity of enterovirus PCR is largely similar after extraction by QIAamp, BioRobot M48, and MagNA Pure; a trend of decreased sensitivity was observed after TRIzol extraction. However, the results of enterovirus PCR were largely concordant in patient samples, indicating that the four extraction methods are suitable for detection of enteroviruses in clinical specimens.
Detection of Circulating gp43 Antigen in Serum, Cerebrospinal Fluid, and Bronchoalveolar Lavage Fluid of Patients with Paracoccidioidomycosis
Authors: Marques da Silva Silvia Helena , Colombo Arnaldo Lopes , Blotta Maria Heloisa Souza Lima , Lopes José Daniel , Queiroz-Telles Flávio , Pires de Camargo Zoilo 
Published: August 2003

ABSTRACT

Paracoccidioidomycosis (PCM) is an important systemic fungal disease, particularly among individuals living and working in rural areas of endemicity in Latin America, who, without antifungal therapy, may develop fatal acute or chronic infection. For such patients, the detection of antibody responses by immunodiffusion is of limited value due to false-negative results. In contrast, the detection of
Paracoccidioides brasiliensis
gp43 circulating antigen may represent a more practical approach to the rapid diagnosis of the disease. Accordingly, an inhibition enzyme-linked immunosorbent assay (inh-ELISA) was developed for the detection of a 43-kDa
P. brasiliensis
-specific epitope incorporating a species-specific murine monoclonal antibody. With sera from patients with acute and chronic forms of the disease (
n
= 81), the overall sensitivity of the test was found to be 95.1%, while specificity was found to be 97.5% compared to that with normal human sera from blood donors (
n
= 93) and sera from patients with other chronic fungal infections (histoplasmosis [
n
= 33] and cryptococcosis [
n
= 20]). The inh-ELISA detected circulating antigen in 100% of patients with the acute form of PCM and in 95.31 and 100% of patients with the chronic multifocal and unifocal forms of PCM according to the patient's clinical presentation. Cerebrospinal fluid from 14 patients with neuroparacoccidioidomycosis and 13 samples of bronchoalveolar lavage fluid from patients with pulmonary unifocal PCM were also tested for gp43 detection, with the test showing 100% sensitivity and specificity. This novel, highly specific inh-ELISA represents a significant addition to the existing tests for the diagnosis of PCM.
Genotypic Identification of Erythromycin-Resistant
Campylobacter
Isolates as
Helicobacter
Species and Analysis of Resistance Mechanism
Authors: Kuijper Ed J. , Stevens Servi , Imamura Toshihiro , de Wever Bob , Claas Eric C. J. 
Published: August 2003

ABSTRACT

The correct identification of
Campylobacter
species remains cumbersome, especially when conventional biochemical tests and antimicrobial susceptibility patterns are used for a phenotypical identification. Correct identification is important for epidemiological purposes and for studying changes in antimicrobial resistance patterns. Six erythromycin-resistant campylobacter strains were investigated by 16S ribosomal DNA (rDNA) sequencing, 23S rDNA sequencing, and restriction fragment length polymorphism analysis of a putative heme-copper oxidase domain described as being specific for thermophilic
Campylobacter
species. Three erythromycin-resistant isolates from feces of human immunodeficiency virus (HIV)-seropositive patients with diarrhea and one blood isolate of from HIV-seropositive patient with cellulitis were identified by 16S rDNA analysis as
Helicobacter cinaedi
, whereas 23S rDNA sequencing suggested
Wolinella succinogenes
. The 16S rDNA sequence data of fecal isolates of two patients with travelers diarrhea revealed
Helicobacter pullorum
and were also in contrast with 23S rDNA sequencing. Of 4
H. cinaedi
isolates, 1 contained the putative heme-copper oxidase gene thought to be specific for thermophilic species. The six erythromycin-resistant
Helicobacter
species had a similar point mutation A2143G in 23S rDNA resembling the macrolides resistance in
Helicobacter pylori.
We conclude that 16S rDNA sequencing should be preferred to 23S rDNA analysis and that macrolide-resistant campylobacter strains should be investigated by this approach for a correct identification.
Transmission ofAnaplasma marginalebyBoophilus microplus: Retention of Vector Competence in the Absence of Vector-Pathogen Interaction
Authors: Futse James E. , Ueti Massaro W. , Knowles Donald P. , Palmer Guy H. 
Published: August 2003

ABSTRACTWhether arthropod vectors retain competence for transmission of infectious agents in the long-term absence of vector-pathogen interaction is unknown. We addressed this question by quantifying the vector competence of two tick vectors, with mutually exclusive tropical- versus temperate-region distributions, for genetically distinct tropical- and temperate-region strains of the cattle pathogenAnaplasma marginale. The tropical cattle tickBoophilus microplus, which has been eradicated from the continental United States for over 60 years, was able to acquire and transmit the temperate St. Maries (Idaho) strain ofA. marginale. Similarly, the temperate-region tickDermacentor andersoniefficiently acquired and transmitted the Puerto Rico strain ofA. marginale. There were no significant quantitative differences in infection rate or number of organisms per tick following feeding on cattle with persistent infections of eitherA. marginalestrain. In contrast, the significantly enhanced replication of the Puerto Rico strain in the salivary gland ofB. microplusat the time of transmission feeding is consistent with adaptation of a pathogen strain to its available vector. However, the transmission of both strains byB. microplusdemonstrates that adaptation or continual interaction between the pathogen and vector is not required for retention of vector competence. Importantly, the results clearly show that reestablishment of acaricide-resistantB. microplusin the United States would be associated withA. marginaletransmission.
Evaluation of a Modified Single-Enzyme Amplified-Fragment Length Polymorphism Technique for Fingerprinting and Differentiating of
Mycobacterium kansasii
Type I Isolates
Authors: Gaafar Ayman , Unzaga M. Josebe , Cisterna Ramón , Clavo Felicitas Elena , Urra Elena , Ayarza Rafael , Martín Gloria 
Published: August 2003

ABSTRACT

The usefulness of single-enzyme amplified-fragment length polymorphism (AFLP) analysis for the subtyping of
Mycobacterium kansasii
type I isolates was evaluated. This simplified technique classified 253 type I strains into 12 distinct clusters. The discriminating power of this technique was high, and the technique easily distinguished between the epidemiologically unrelated control strains and our clinical isolates. Overall, the technique was relatively rapid and technically simple, yet it gave reproducible and discriminatory results. This technique provides a powerful typing tool which may be helpful in solving many questions concerning the reservoirs, pathogenicities, and modes of transmission of these isolates.
Detection of Methicillin-Resistant
Staphylococcus aureus
(MRSA) in Blood with the EVIGENE MRSA Detection Kit
Authors: Levi Katrina , Towner Kevin J. 
Published: August 2003

ABSTRACT

A total of 200 blood cultures containing putative staphylococci were analyzed by a commercial gene probe hybridization assay (EVIGENE; Statens Serum Institut, Copenhagen, Denmark), and 18 were identified as methicillin-resistant
Staphylococcus aureus
(MRSA) positive. Of these, 17 were positive by PCR and 16 were positive by culture. Detailed analysis of the discrepant results showed that the EVIGENE kit allowed specific identification of MRSA in blood cultures without any of the drawbacks associated with PCR.
Close Relationship between G8-Serotype Bovine and Human Rotaviruses Isolated in Nigeria
Authors: Adah Mohammed I. , Nagashima Shigeo , Wakuda Mitsutaka , Taniguchi Koki 
Published: August 2003

ABSTRACTA bovine rotavirus, NGRBg8, isolated from the feces of a calf with diarrhea in Nigeria was characterized by reverse transcription-PCR, nucleotide sequence analysis, and Northern blot hybridization. The nucleotide sequence of the VP7 gene of the strain was most closely related to that of a Nigerian human G8-serotype strain, HMG035 (99.9%). The NSP1 gene of strain NGRBg8 is highly related (99.4%) to that of a Thai G8 bovine strain, A5-10. Northern blot hybridization revealed a high overall genomic relatedness of bovine strain NGRBg8 with human strain HMG035; all 11 RNA segments hybridized to each other. Thus, the results show the close relationship between G8 bovine and human rotaviruses in Nigeria.
Intra-cell machine layout associated with flexible production and transport systems
Authors: Chaieb I , Korbaa O 
Published: August 2003

This paper deals with the intra-cell machines layout problem, an intermediate step of the workshop design. In this workshop, the production systems belong to a specific class: the flexible manufacturing systems (FMS). The problem consists in finding a positioning of machines in a given manufacturing cell that is the most appropriate for the production process and that optimizes the criterion chosen for minimizing the distances between machines and so minimizing the total transportation time. This problem has been solved in the literature by developing heuristics based on the simulating annealing approach. In order to avoid the problems confronted by some authors, consisting of redefining all the parameters each time, the problem is changed. A generic method is determined by mathematically formulating the machine layout problem. Thus, when it is linear, the problem is solved by CPLEX and the optimal solution is given within a few seconds. When the configuration of the transport system leads to a non-linear problem, it is solved using an enumerative algorithm. In the literature, some restrictive hypotheses were set when solving the machine layout problem. In fact, the operating sequences were supposed to be linear and only one exemplar of each transformation resource was considered. In this paper three kinds of flexibility are introduced: multiplicity of the transformation resources, flexibility of the operating sequences and installation of a shortcut in the manufacturing cell. The method given here is used to solve the machine layout problem when taking flexibility into consideration. After proving that introducing flexibility in the production or the transport system increases the non-linearity of the problem, the algorithm developed to solve an illustrative example of a cell containing identical machines is described. The considered resources perform different part types having flexible operating sequences. To join distant machines, a shortcut was installed in the cell. Based on an enumerative method, the algorithm provides an optimal solution within a few seconds. The ability to solve the problem using an enumerative method and to obtain an optimal solution in a reasonable time is due to the fact that the step consisting of positioning the machines comes after the step of grouping machines into cells, so the number of machines in each cell is small enough to use the enumeration.
Inorganic nitrogen retention in acid‐sensitive lakes in southern Norway and southern Ontario, Canada—a comparison of mass balance data with an empirical N retention model
Authors: Kaste Ø. , Dillon P. J. 
Published: August 2003

AbstractIn‐lake retention of inorganic nitrogen species (nitrate and ammonium) was estimated from mass balances in five acid‐sensitive lakes in southern Norway and eight in southern Ontario, Canada, to evaluate an empirical in‐lake N retention (RN) model. This model is included in the First‐order Acidity Balance (FAB) model, which currently is used for calculation of critical acid loads and exceedances in many countries. To estimate in‐lake RN, the FAB model uses a recommended mass transfer coefficient (SN) of 5 m year−1, which mainly is derived from NO3− mass balances in Canadian lakes. To date, the in‐lake RN model has not been evaluated for large parts of Europe. At the Norwegian study sites receiving the highest N deposition (>120 meq m−2 year−1) the net in‐lake retention of inorganic N (TIN) exceeded the corresponding terrestrial retention by a factor of 1·1–2·6. Despite differences in N loading and hydrology at the Norwegian and Canadian sites, both the mean mass transfer coefficients for NO3− (SNO3; 6·5 versus 5·6 m year−1) and TIN (STIN; 7·9 versus 7·0 m year−1) were of comparable magnitude. Both mean values and ranges of SNO3 suggest that the default SN value presently recommended for FAB model applications seems valid over a large range in N inputs and areal water loads (qs). However, owing to the relatively few data available for lakes with high qs values (15–150 m year−1), it is recommended that more lakes within this range be included in future studies to obtain a more precise prediction of in‐lake N retention over a wide qs gradient. Also, when considering that the FAB model treats all inorganic N leaching from a catchment as NO3−, it seems reasonable to use a default STIN value instead of just SNO3 when estimating in‐lake RN. In that case, the in‐lake RN presently calculated by the FAB model might be slightly underestimated. Copyright © 2003 John Wiley & Sons, Ltd.
Comparison of trends in stream water quality
Authors: Potts J. M. , Hirst D. , Miller J. D. , Edwards A. C. , Elston D. A. 
Published: August 2003

AbstractA method is described for assessing the strength of evidence for differences in the trends in chemical concentrations in stream water between catchments. A smoothing spline technique is used to model changes in water quality as a result of changes in flow rates, seasonal effects and an underlying trend. The method involves fitting the model twice, once with the underlying trends constrained to be identical for each river and once with the trends unconstrained. Statistical properties are assessed by simulation methods that allow for the autocorrelation in the residuals from the unconstrained fit. The method is applied to data from two streams in the Balquhidder catchments in the Highlands of Scotland and to data from the Dee, Don and Ythan rivers in the north‐east of Scotland. Copyright © 2003 John Wiley & Sons, Ltd.
A qualitative and quantitative evaluation of experimental model catchment evolution
Authors: Hancock G. R. , Willgoose G. R. 
Published: August 2003

AbstractDue to the geological time scales required for observation of catchment evolution, surrogates or analogues of field data are necessary to understand long‐term processes. To investigate long‐term catchment behaviour, two experimental model catchments that developed without rigid boundaries under controlled conditions are examined and a qualitative and quantitative analysis of their evolution is presented. Qualitatively, the experimental catchments have the visual appearance of field scale data. Observation demonstrates that changes in catchment shape and network form are conservative. Quantitative analysis suggests that the catchments reach an equilibrium form while a reduction in the channel network occurs. While the catchments are laboratory scale models, the results provide insights into field scale behaviour. Copyright © 2003 John Wiley & Sons, Ltd.
A downward approach to identifying the structure and parameters of a process‐based model for a small experimental catchment
Authors: Chirico Giovanni Battista , Grayson Rodger B. , Western Andrew W. 
Published: August 2003

AbstractAn intensive field monitoring programme was conducted in 1998 and 1999 in an 84 ha catchment located on the North Island of New Zealand. The data collected includes six soil moisture patterns, 12 soil moisture time‐series, flow at the outlets of two subcatchments of 56 ha and 28 ha, rainfall and other meteorological data. This data set was used in a downward approach to constrain the conceptualisations and the parameters of a terrain‐based distributed model, aiming to simulate the spatial and temporal variability of the soil moisture and the flow response observed in the two subcatchments. The principal mechanism producing runoff was assessed by a preliminary data analysis, involving rainfall, flow and soil moisture time‐series as well as the simulation of infiltration processes at the point scale. Runoff was identified as being mainly produced by saturation excess across the entire monitoring period, despite the high intensity rainfall observed in that area. The model soil‐water‐retention parameters were determined from the soil moisture patterns. The other soil parameters controlling the soil transmissivity were determined by calibration against the observed flow in 1999 in the 56 ha subcatchment, accumulated at the daily scale. The analysis of the flow data at the hourly scale illustrated the need for a more complex subsurface transmissivity function in order to produce lateral storm flow with a larger range of celerity. A simple solution was to modify the decay of the lateral transmissivity with the soil moisture content by adding a second component activated only for soil moisture close to saturation. The additional parameters were calibrated against the observed hourly flow in 1999 in the 56 ha subcatchment. The remaining data were used for validation purposes. This data‐driven, downward approach to identifying the model conceptualisation and parameters resulted in a model capable of reproducing the observed catchment behaviour while minimising model complexity. Copyright © 2003 John Wiley & Sons, Ltd.
NF–FF transformation with cylindrical scanning from nonuniformly distributed data
Authors: Ferrara F. , Gennarelli C. , Riccio G. , Savarese C. 
Published: August 2003

AbstractTwo efficient probe‐compensated near‐field–far‐field (NF–FF) transformation techniques with cylindrical scanning requiring a minimum number of irregularly spaced data, are proposed. Singular value decomposition (SVD) method is applied to evaluate the uniformly distributed samples, whose positions are fixed by a nonredundant sampling representation of the field, from the irregularly spaced ones. Then, the voltage data needed by standard NF–FF transformation or by a non‐conventional one recently developed by the authors are efficiently evaluated via an optimal sampling interpolation algorithm. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 4–8, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11109
An accurate FDTD simulation technique using relatively coarse mesh for modeling PEC planar structures
Authors: Zhou Baixin , Wang Sicong , Yu Wenhua 
Published: August 2003

AbstractIn this paper, we present a fast convergent technique that can generate an accurate FDTD simulation result using a relatively coarse mesh for PEC planar structures if an effective factor is properly selected. The effective size of a PEC is about one half cell smaller than its actual dimensions regardless of cell size. A microwave patch antenna and a low pass filter are used to validate the proposed scheme. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 17–19, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11113