bluuebunny/crossref_metadata_2025_split huggingface dataset:
The observer‐based linear quadratic sub‐optimal digital tracker for analog systems with input and state delays
Authors: Huang C. M. , Tsai J. S.‐H. , Provence R. S. , Shieh L. S. 
Published: August 2003

AbstractThis paper presents a new observer‐based sub‐optimal digital tracker for the continuous‐time system with input and state time delays. We directly convert the continuous‐time input‐state delayed system into an equivalent discrete‐time input‐state delayed model and its extended discrete‐time delay‐free model. In addition, we directly discretize the linear quadratic performance index specified in the continuous‐time domain into an equivalent decoupled discrete‐time performance index using the newly developed extended delay‐free model. As a consequence, the well‐developed discrete‐time optimal control theory for discrete‐time delay‐free system can be applied to determine the optimal digital tracker for the continuous‐time input‐state delayed system. When the states of the continuous‐time input‐state delayed system are not available for measurements, we develop a sub‐optimal digital observer for the original continuous‐time input‐state delayed system using the state‐matching digital redesign technique and the digital‐to‐analog model conversion technique. As a result, the proposed observer‐based linear quadratic digital tracker is able to make the output of the digitally controlled continuous‐time input‐state delayed system sub‐optimally track the desired reference signals. An illustrative example is presented to demonstrate the effectiveness of the proposed design methodology. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of economies of scope by data envelopment analysis: comparison of efficient frontiers
Authors: Morita Hiroshi 
Published: August 2003

AbstractEconomies of scope exist when joint production is more efficient than separate production for several kinds of activities. The main purposes are to develop a method for identifying the economies of scope by using data envelopment analysis, which involves the use of non‐parametric production frontiers and does not require cost information on inputs and outputs. The economies of scope are measured by comparing efficient frontiers, where the most robust multipliers are defined for evaluation of the dominance relation of efficient frontiers.
Significance of Pretreatment Analysis of Hepatitis C Virus Genotype 1b Hypervariable Region 1 Sequences To Predict Antiviral Outcome
Authors: Gaudy Catherine , Moreau Alain , Veillon Pascal , Temoin Stephanie , Lunel Francoise , Goudeau Alain 
Published: August 2003

ABSTRACT
The heterogeneity of hypervariable region 1 (HVR1), located at the amino terminus of the E2 envelope, may be involved in resistance to alpha interferon (IFN-α) treatment. We investigated whether peculiar HVR1 domain profiles before treatment were associated with the maintenance of sensitivity or the appearance of resistance to treatment. Fifteen patients infected with hepatitis C virus genotype 1b and treated with IFN with or without ribavirin were selected. Ten responded to treatment (groups R1 and R2) and five did not (group NR). The amino acid sequences of 150 naturally occurring HVR1 variants present in the serum before therapy were compared in relation to treatment outcome. HVR1 variants from the NR group contained a constant nonantigenic amino acid segment that was not found in HVR1 variants from the R groups.
Comparative Evaluation of Real-Time PCR Assays for Detection of the Human Metapneumovirus
Authors: Côté Stéphanie , Abed Yacine , Boivin Guy 
Published: August 2003

ABSTRACT

The human metapneumovirus (hMPV) is a new member of the
Paramyxoviridae
family associated with acute respiratory tract infections in humans. The objective of this study was to compare the sensitivity of real-time RT-PCR assays performed in a LightCycler instrument and designed to amplify the viral nucleoprotein (N), matrix (M), fusion (F), phosphoprotein (P), and polymerase (L) genes. In a first evaluation of 20 viral cultures with characteristics compatible with hMPV cytopathic effect, the PCR positivity rates were 100, 90, 75, 60, and 55% using primers for the N, L, M, P, and F genes. In a second evaluation of 10 nasopharyngeal aspirates from children with bronchiolitis and found to be positive for the hMPV N gene, the PCR positivity rates for the L, M, P, and F genes were 90, 60, 30, and 80%, respectively. The analytic sensitivity of the real-time RT-PCR assay for the hMPV N gene was 100 copies using a transcribed viral plasmid. In conclusion, real-time PCR assays aimed at amplifying the N and L genes which are coding for two internal viral proteins appear particularly suitable for hMPV diagnostic.
Vaginal Swabs Are Appropriate Specimens for Diagnosis of Genital Tract Infection with
Chlamydia trachomatis
Authors: Schachter Julius , McCormack William M. , Chernesky Max A. , Martin David H. , Van Der Pol Barbara , Rice Peter A. , Hook Edward W. , Stamm Walter E. , Quinn Thomas C. , Chow Joan M. 
Published: August 2003

ABSTRACT

Because self-collected vaginal swabs (VS) are potentially very useful for screening asymptomatic women for
Chlamydia trachomatis
infection, a multicenter study evaluated that specimen with nucleic acid amplification tests (NAATs). The objective was to determine whether VS are equal to Food and Drug Administration (FDA)-cleared specimens (cervical swabs and first-catch urines [FCU]) for diagnosing genital chlamydial infection. All NAATs then commercially available (October 1996 to October 1999) were used (ligase chain reaction [LCx Probe System; Abbott Laboratories, Abbott Park, Ill.]; PCR [Amplicor; Roche Molecular Systems, Branchburg, N.J.]; and transcription-mediated amplification, [Amplified CT Assay; Gen-Probe Inc., San Diego, Calif.]). NAATs were performed on FCU, urethral, cervical, self- and clinician-collected VS. Sensitivity was compared to isolation using cervical and urethral swabs. Agreement of NAAT results between VS and cervical swabs or FCU was calculated. Specimens from 2,517 15- to 25-year-old asymptomatic women attending clinics at nine different centers were evaluated. Results with self- and clinician-collected VS were equivalent and were at least as good as results with FCU and cervical swabs. Across all sites, summary specificities for all specimens were >99%. Among culture-positive women, NAAT sensitivity with VS (93%) was as high as or higher than NAAT sensitivity with cervical swabs (91%) or FCU (80.6%) or culture of cervical swabs (83.5%). VS are appropriate specimens for diagnosing chlamydial genital tract infection by NAATs. That patients can efficiently collect them offers important benefits for screening programs. It would be beneficial for public health programs if the NAAT manufacturers sought FDA clearance for this specimen.
Monitoring Response to Antiviral Therapy for Patients with Chronic Hepatitis C Virus Infection by a Core-Antigen Assay
Authors: Rebucci Chiara , Cerino Antonella , Cividini Agostino , Timo Letizia , Furione Milena , Mondelli Mario U. 
Published: August 2003

ABSTRACT
A recently released immunoassay detecting total serum hepatitis C virus (HCV) core antigen was used to prospectively monitor virological responses to antiviral treatment in patients with chronic HCV infection. Sustained responders cleared core protein from serum within the first month of therapy and maintained stably negative values for the entire duration of follow-up after treatment discontinuation. However, patients who relapsed or failed to respond showed transient negative values and could not be accurately discriminated either because of the intrinsic lower sensitivity of the core-antigen assay than those of molecular assays or because of differentially regulated secretion of immunoreactive core protein from infected hepatocytes.
Scedosporium prolificans
Osteomyelitis in an Immunocompetent Child Treated with Voriconazole and Caspofungin, as Well as Locally Applied Polyhexamethylene Biguanide
Authors: Steinbach William J. , Schell Wiley A. , Miller Jackie L. , Perfect John R. 
Published: August 2003

ABSTRACT

Scedosporium
species are increasingly isolated from immunocompromised and immunocompetent patients. Unfortunately,
Scedosporium
infections are generally resistant to amphotericin B, and
Scedosporium prolificans
strains are particularly resistant to the antifungal agents now in use. We report here on an immunocompetent child with
S. prolificans
-associated osteomyelitis successfully treated with debridement, local irrigation with polyhexamethylene biguanide, and the systemic administration of voriconazole and caspofungin despite poor in vitro activity of voriconazole alone against the isolate. We also review the treatments and outcomes of 28 reported cases of osteomyelitis or septic arthritis caused by
Scedosporium
species in immunocompetent patients.
Improvement of the yield of physiologically active oligosaccharides in continuous hydrolysis of chitosan using immobilized chitosanases
Authors: Kuroiwa Takashi , Ichikawa Sosaku , Sato Seigo , Mukataka Sukekuni 
Published: August 2003

AbstractThe continuous production of chitosan oligosaccharides using a packed‐bed enzyme reactor was investigated as to the effects of the operation conditions on the yield of pentamers and hexamers of chitosan oligosaccharides. A column reactor packed with immobilized chitosanases prepared by the multipoint attachment method was used for continuous hydrolysis of chitosan. In this reactor, the decrease of the yield of the target intermediate oligosaccharides due to axial mixing was negligible. The surface enzyme density of the support and flow rate of the substrate solution significantly affected the maximum yield of pentamers and hexamers. These effects were summarized as a correlation with the Damköhler number (Da), defined as the ratio of the maximum reaction rate to the maximum mass transfer rate. The optimum condition was determined based on Da. Under the optimized condition (Da = 0.12), pentamers and hexamers could be produced continuously for a month with a yield of over 35% (7 kg/m3 in concentration). © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 121–127, 2003.
Using financing to motivate a for‐profit health care provider to deliver family planning services: Is it a cost‐effective intervention? A study of AAR health services in Kenya
Authors: Chee Grace 
Published: August 2003

AbstractDespite much discussion of the role of private health care providers, there are no tried and tested models for supporting for‐profit providers in ways that produce cost‐effective public health outcomes. This paper examines the cost effectiveness of using a loan mechanism to motivate a for‐profit provider to deliver family planning services. The intervention examined directly resulted in a private provider delivering family planning services, however, it did not create a long‐term financial incentive for the private provider to promote the use of family planning. The cost effectiveness of this intervention is analysed using a methodology that captures long term sustainability of the intervention within a traditional family planning outcome measure, such as couple years protection (CYP), by discounting future expected CYPs. Depending on the method for analysing costs and assumptions regarding future CYPs, this intervention produced family planning outcomes at no or very low cost ($0–$4.11 per CYP). The analysis demonstrates that innovative family planning interventions with private providers should be considered as they can be more cost effective than traditional programmes. Copyright © 2003 John Wiley & Sons, Ltd.
Characteristics of organic matter as indicators of pollution from small‐scale livestock and nitrate contamination of shallow groundwater in an agricultural area
Authors: Kim Rak‐Hyeon , Lee Jeongho , Chang Ho‐Wan 
Published: August 2003

AbstractThe main purpose of this study was to examine the hydrogeochemical factors leading to nitrate contamination of shallow groundwater in an agricultural area. Another purpose was to identify relationships between variations in organic matter levels (as estimated by the BOD and COD parameters) of groundwater that transports effluent from small‐scale livestock holdings. Major cations, anions, BOD and COD of organic matter and total coliforms were analysed. It was found that groundwaters beneath cultivated areas and areas carrying livestock had higher concentrations of calcium, nitrate and chloride than did freshwater. Above all, the nitrification process increased concentrations of nitrate. Nitrate levels were depressed in some places where the groundwater was low in dissolved oxygen. Groundwaters affected by livestock activities showed high concentrations of organic matter (BOD, COD) and high microbial concentrations (as indicated by total coliforms). The COD/BOD ratio increased in the downward direction. It was inferred that this was due to the faster loss of easily biodegradable organic matter compared with non‐biodegradable organic matter proceeding away from a discharge. Accordingly, it is possible to trace effluent in a small area back to a point source by monitoring the COD/BOD ratio of groundwater. Copyright © 2003 John Wiley & Sons, Ltd.
Predicting space–time variability of hourly streamflow and the role of climate seasonality: Mahurangi Catchment, New Zealand
Authors: Atkinson S. E. , Sivapalan M. , Viney N. R. , Woods R. A. 
Published: August 2003

AbstractWe present a systematic approach to achieving accurate hourly streamflow predictions at locations internal to a catchment, potentially with minimal calibration. Each step in this approach is meant to provide insight into the relative importance of catchment and climatic properties (rainfall, soil, vegetation, topography), their spatial variability, and their influence on the spatial and temporal variability of streamflows. This has been made possible through the use of a simple conceptual model design requiring minimal calibration and with physically meaningful catchment parameters estimated mostly a priori from landscape data, and climatic variables. Eight model types originating from this simple conceptual model design, with complexity ranging from lumped to fully distributed, were tested over summer and winter periods at the Mahurangi Catchment, New Zealand, and the preferred model identified using statistical assessment criteria. Results of the simulations suggest that, although the required model complexity was found to be a function of the season (summer versus winter), a fully distributed representation is most appropriate for accurate predictions under all seasonal climate conditions. Using this model, the success of hourly flow predictions in space–time was assessed and sensitivity analysis used to identify the dominant controls on the timing and magnitude of hourly flow predictions and to investigate the adequacy of the assumption of homogeneity for a number of catchment properties. Copyright © 2003 John Wiley & Sons, Ltd.
Simple two‐state protein folding kinetics requires near‐levinthal thermodynamic cooperativity
Authors: Kaya Hüseyin , Chan Hue Sun 
Published: August 2003

AbstractSimple two‐state folding kinetics of many small single‐domain proteins are characterized by chevron plots with linear folding and unfolding arms consistent with an apparent two‐state description of equilibrium thermodynamics. This phenomenon is hereby recognized as a nontrivial heteropolymer property capable of providing fundamental insight into protein energetics. Many current protein chain models, including common lattice and continuum Gō models with explicit native biases, fail to reproduce this generic protein property. Here we show that simple two‐state kinetics is obtainable from models with a cooperative interplay between core burial and local conformational propensities or an extra strongly favorable energy for the native structure. These predictions suggest that intramolecular recognition in real two‐state proteins is more specific than that envisioned by common Gō‐like constructs with pairwise additive energies. The many‐body interactions in the present kinetically two‐state models lead to high thermodynamic cooperativity as measured by their van't Hoff to calorimetric enthalpy ratios, implying that the native and denatured conformational populations are well separated in enthalpy by a high free‐energy barrier. It has been observed experimentally that deviations from Arrhenius behavior are often more severe for folding than for unfolding. This asymmetry may be rationalized by one of the present modeling scenarios if the effective many‐body cooperative interactions stabilizing the native structure against unfolding is less dependent on temperature than the interactions that drive the folding kinetics. Proteins 2003;52:510–523. © 2003 Wiley‐Liss, Inc.
A multi‐attribute motivational model of consumer choice based on a new outranking relation
Authors: Tavares L. Valadares 
Published: August 2003

AbstractMultiple models have been proposed to describe different patterns of consumer behavior, that is becoming more complex and diversified (so called “postmodern consumer”), but little attention has been given to explore the potential of the approach based on pairwise comparisons. In this paper, a new model of consumer choice is developed considering that: the space of the perceptual attributes includes two sub‐spaces; the motivational attributes which are responsible for the generation of a motivational drive or force; other relevant decisional attributes. The process of choice is modeled by an outranking relation that is appropriate to describe pairwise comparisons. An example is presented illustrating the applicability of this model to the choice of a sport car, based on the two groups of attributes. There is general agreement about the impossibility of developing an universal model for consumer choice but it is expected that this model can enrich the list of available candidates. Major advantages are: the explicit distinction between motivational and non‐motivational attributes. These two groups play a different role in the process of consumer decision making; the description of the consumer choice in terms of successive pairwise comparisons; and the use of a new outranking relation appropriate to model the choice made by the consumer in terms of his motivation and avoiding the integration of multiple attributes through the usual weighting functions which are hardly confirmed by empirical evidences.
The use of problem structuring methods in strategic health planning
Authors: Thunhurst Colin 
Published: August 2003

AbstractProblem structuring methods have emerged as a powerful weapon in the armoury of operational research over the past twenty years. This paper will present and discuss the value of adopting formal problem structuring methods as part of the strategic health planning process. It will outline how problem structuring methods were embedded into the strategic health planning system developed for provincial health planning in Pakistan. It will draw upon the author's recent experience of using this system to assist the Government of the North West Frontier Province of Pakistan to develop a ‘Master’ Health Plan for the Federally Administered Tribal Areas of Pakistan. It will discuss the systematic use of problem structuring methods in the District Implementation Planning Process in Malawi. It will consider the value of adopting similar methods in developed health systems, particularly their role in bridging the gap in a ‘partnership model’ between community groups and statutory decision‐makers.
Bacterial Diversity in Cases of Lung Infection in Cystic Fibrosis Patients: 16S Ribosomal DNA (rDNA) Length Heterogeneity PCR and 16S rDNA Terminal Restriction Fragment Length Polymorphism Profiling
Authors: Rogers G. B. , Hart C. A. , Mason J. R. , Hughes M. , Walshaw M. J. , Bruce K. D. 
Published: August 2003

ABSTRACT

The leading cause of morbidity and mortality in cystic fibrosis (CF) patients stems from repeated bacterial respiratory infections. Many bacterial species have been cultured from CF specimens and so are associated with lung disease. Despite this, much remains to be determined. In the present study, we characterized without prior cultivation the total bacterial community present in specimens taken from adult CF patients, extracting DNA directly from 14 bronchoscopy or sputum samples. Bacterial 16S ribosomal DNA (rRNA) gene PCR products were amplified from extracted nucleic acids, with analyses by terminal restriction fragment length polymorphism (T-RFLP), length heterogeneity PCR (LH-PCR), and sequencing of individual cloned PCR products to characterize these communities. Using the same loading of PCR products, 12 distinct T-RFLP profiles were identified that had between 3 and 32 T-RFLP bands. Nine distinct LH-PCR profiles were identified containing between one and four bands. T-RFLP bands were detected in certain samples at positions that corresponded to pathogens cultured from CF samples, e.g.,
Burkholderia cepacia
and
Haemophilus influenzae
. In every sample studied, one T-RFLP band was identified that corresponded to that produced by
Pseudomonas aeruginosa.
A total of 103 16S rRNA gene clones were examined from five patients.
P. aeruginosa
was the most commonly identified species (59% of clones).
Stenotrophomonas
species were also common, with eight other (typically anaerobic) bacterial species identified within the remaining 17 clones. In conclusion, T-RFLP analysis coupled with 16S rRNA gene sequencing is a powerful means of analyzing the composition and diversity of the bacterial community in specimens sampled from CF patients.
Enzootic Transmission of
Anaplasma bovis
in Nantucket Cottontail Rabbits
Authors: Goethert Heidi K. , Telford Sam R. 
Published: August 2003

ABSTRACT

Serological studies of cottontail rabbits sampled from Nantucket Island, Mass., have suggested exposure to at least two ehrlichiae. The agent of human granulocytic ehrlichiosis (
Anaplasma phagocytophilum
) is intensely enzootic in rabbits there, but the identity of the other ehrlichial infection remains undescribed. We sampled rabbits over five transmission seasons and tested their blood and tissues for evidence of infection using PCR targeting an
Ehrlichia
genus-wide 16S rDNA target. Sequence analysis of positive amplicons revealed the presence of
Anaplasma bovis
, an agent not known to be present in North America. The average annual prevalence of
A. bovis
within rabbits, as determined by PCR of blood samples, was 18%.
Haemaphysalis leporispalustris
appears to serve as vector. The public health (human or veterinary) significance of this finding remains speculative.
Rhizobium
(
Agrobacterium
)
radiobacter
Identified as a Cause of Chronic Endophthalmitis Subsequent to Cataract Extraction
Authors: Namdari Hassan , Hamzavi Sirus , Peairs Randall R. 
Published: August 2003

ABSTRACT

Herein, we report a case of chronic endophthalmitis caused by a ceftazidime-resistant
Rhizobium radiobacter
strain in a 62-year-old male. The patient underwent an uneventful cataract extraction of the right eye a week prior to the appearance of symptoms (pain, redness, and blurring vision) which developed following a golf outing. Upon admission the patient received an emergency vitrectomy. The patient remained symptomatic, and
R. radiobacter
was isolated repeatedly from vitreous fluid cultures over a 5-month period. Ultimately, the infection responded to intravitreal gentamicin, oral ciprofloxacin, and removal of the lens implant.