bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of delayed mating and male mating history on the reproductive potential of Leucoptera coffeella (Lepidoptera: Lyonetiidae)
Authors: Michereff Mirian Fernandes Furtado , Vilela Evaldo Ferreira , Filho Miguel Michereff , Nery Daniela M. S. , Thièbaut José T. 
Published: July 2004

Abstract  1 Despite the importance of Leucoptera coffeella (Guérin‐Mèneville) in coffee production worldwide, there is a lack of information on its reproduction. This knowledge will help in mass rearing, and support the development of behavioural control techniques for this insect. The present study determined the effects of delayed mating and previous matings of male L. coffeella on fecundity, egg viability and frequency of female remating.2 The highest levels of fecundity and egg viability were obtained from matings of 1–3‐day‐old females. When females mated at 5 days of age, there were reductions of 40% in oviposition and of 43% in egg viability.3 Females mated with 2‐day‐old virgin males were more fecund than those mated with older males; egg viability was also low (18%) from females mated with older males.4 Virgin females that mated with virgin males laid a greater number of eggs than those mated with previously copulated males. Egg viability decreased with the increase in the number of previous male matings.5 Five‐day‐old females remated in greater proportion than 2–3‐day‐old females. Females that copulated with males that had previously mated three times had higher rates of remating than those that copulated with virgin males.6 The results obtained indicate that 1–3 days after emergence is the optimum age for mating. The implications of these findings for the control of L. coffeella by synthetic sex pheromone are discussed.
Bayesian Variable Selection and Regularization for Time–Frequency Surface Estimation
Authors: Wolfe Patrick J. , Godsill Simon J. , Ng Wee-Jing 
Published: July 2004

SummaryWe describe novel Bayesian models for time–frequency inverse modelling of non-stationary signals. These models are based on the idea of a Gabor regression, in which a time series is represented as a superposition of translated, modulated versions of a window function exhibiting good time–frequency concentration. As a necessary consequence, the resultant set of potential predictors is in general overcomplete—constituting a frame rather than a basis—and hence the resultant models require careful regularization through appropriate choices of variable selection schemes and prior distributions. We introduce prior specifications that are tailored to representative time series, and we develop effective Markov chain Monte Carlo methods for inference. To highlight the potential applications of such methods, we provide examples using two of the most distinctive time–frequency surfaces—speech and music signals—as well as standard test functions from the wavelet regression literature.
Wavelet Deconvolution in a Periodic Setting
Authors: Johnstone Iain M. , Kerkyacharian Gérard , Picard Dominique , Raimondo Marc 
Published: July 2004

SummaryDeconvolution problems are naturally represented in the Fourier domain, whereas thresholding in wavelet bases is known to have broad adaptivity properties. We study a method which combines both fast Fourier and fast wavelet transforms and can recover a blurred function observed in white noise with O{n log (n)2} steps. In the periodic setting, the method applies to most deconvolution problems, including certain ‘boxcar’ kernels, which are important as a model of motion blur, but having poor Fourier characteristics. Asymptotic theory informs the choice of tuning parameters and yields adaptivity properties for the method over a wide class of measures of error and classes of function. The method is tested on simulated light detection and ranging data suggested by underwater remote sensing. Both visual and numerical results show an improvement over competing approaches. Finally, the theory behind our estimation paradigm gives a complete characterization of the ‘maxiset’ of the method: the set of functions where the method attains a near optimal rate of convergence for a variety of Lp loss functions.
Nonparametric Multistep-Ahead Prediction in Time Series Analysis
Authors: Chen Rong , Yang Lijian , Hafner Christian 
Published: July 2004

SummaryWe consider the problem of multistep-ahead prediction in time series analysis by using nonparametric smoothing techniques. Forecasting is always one of the main objectives in time series analysis. Research has shown that non-linear time series models have certain advantages in multistep-ahead forecasting. Traditionally, nonparametric k-step-ahead least squares prediction for non-linear autoregressive AR(d) models is done by estimating E(Xt+k |Xt, …, Xt−d+1) via nonparametric smoothing of Xt+k on (Xt, …, Xt−d+1) directly. We propose a multistage nonparametric predictor. We show that the new predictor has smaller asymptotic mean-squared error than the direct smoother, though the convergence rate is the same. Hence, the predictor proposed is more efficient. Some simulation results, advice for practical bandwidth selection and a real data example are provided.
A Method for Combining Inference Across Related Nonparametric Bayesian Models
Authors: Müller Peter , Quintana Fernando , Rosner Gary 
Published: July 2004

SummaryWe consider the problem of combining inference in related nonparametric Bayes models. Analogous to parametric hierarchical models, the hierarchical extension formalizes borrowing strength across the related submodels. In the nonparametric context, modelling is complicated by the fact that the random quantities over which we define the hierarchy are infinite dimensional. We discuss a formal definition of such a hierarchical model. The approach includes a regression at the level of the nonparametric model. For the special case of Dirichlet process mixtures, we develop a Markov chain Monte Carlo scheme to allow efficient implementation of full posterior inference in the given model.
Joint Response Graphs and Separation Induced by Triangular Systems
Authors: Wermuth Nanny , Cox D. R. 
Published: July 2004

SummaryWe consider joint probability distributions generated recursively in terms of univariate conditional distributions satisfying conditional independence restrictions. The independences are captured by missing edges in a directed graph. A matrix form of such a graph, called the generating edge matrix, is triangular so the distributions that are generated over such graphs are called triangular systems. We study consequences of triangular systems after grouping or reordering of the variables for analyses as chain graph models, i.e. for alternative recursive factorizations of the given density using joint conditional distributions. For this we introduce families of linear triangular equations which do not require assumptions of distributional form. The strength of the associations that are implied by such linear families for chain graph models is derived. The edge matrices of chain graphs that are implied by any triangular system are obtained by appropriately transforming the generating edge matrix. It is shown how induced independences and dependences can be studied by graphs, by edge matrix calculations and via the properties of densities. Some ways of using the results are illustrated.
Analysis of Longitudinal Data with Irregular, Outcome-Dependent Follow-Up
Authors: Lin Haiqun , Scharfstein Daniel O. , Rosenheck Robert A. 
Published: July 2004

SummaryA frequent problem in longitudinal studies is that subjects may miss scheduled visits or be assessed at self-selected points in time. As a result, observed outcome data may be highly unbalanced and the availability of the data may be directly related to the outcome measure and/or some auxiliary factors that are associated with the outcome. If the follow-up visit and outcome processes are correlated, then marginal regression analyses will produce biased estimates. Building on the work of Robins, Rotnitzky and Zhao, we propose a class of inverse intensity-of-visit process-weighted estimators in marginal regression models for longitudinal responses that may be observed in continuous time. This allows us to handle arbitrary patterns of missing data as embedded in a subject's visit process. We derive the large sample distribution for our inverse visit-intensity-weighted estimators and investigate their finite sample behaviour by simulation. Our approach is illustrated with a data set from a health services research study in which homeless people with mental illness were randomized to three different treatments and measures of homelessness (as percentage days homeless in the past 3 months) and other auxiliary factors were recorded at follow-up times that are not fixed by design.
Smoothing Spline Estimation in Varying-Coefficient Models
Authors: Eubank R. L. , Huang Chunfeng , Maldonado Y. Muñoz , Wang Naisyin , Wang Suojin , Buchanan R. J. 
Published: July 2004

SummarySmoothing spline estimators are considered for inference in varying-coefficient models with one effect modifying covariate. Bayesian ‘confidence intervals’ are developed for the coefficient curves and efficient computational methods are derived for computing the curve estimators, fitted values, posterior variances and data-adaptive methods for selecting the levels of smoothing. The efficacy and utility of the methodology proposed are demonstrated through a small simulation study and the analysis of a real data set.
Pain and sensory complaints in multiple sclerosis
Authors: Beiske A. G. , Pedersen E. D. , Czujko B. , Myhr K.‐M. 
Published: July 2004

Pain is a frequent and disabling symptom among multiple sclerosis (MS) patients. The importance of this problem was investigated in a hospital based MS population.A total of 142 MS patients underwent neurological examination and a structured interview for registration of pain and sensory symptoms.One‐hundred and five patients reported sensory and/or pain symptoms. Pain was reported by 93 patients and was most frequently located in the limbs and lumbar region. The presence of pain was independent of gender, age at onset and examination, disability, disease course and duration. The most frequently reported characteristics of the symptoms were paresthesia, neuralgia and deep muscular aching. About 40% of the patients reported that the symptoms had important influence on daily activities. Only one‐third of the patients were treated for their pain.Pain is a frequent and disabling symptom, independent of demographic and clinical variables in MS patients. The low frequency of treatment for these symptoms indicates a need for improved attention to this problem.
Healing of intrabony defects following surgical treatment with or without an Er:YAG laser
Authors: Sculean Anton , Schwarz Frank , Berakdar Mohammad , Windisch Péter , Arweiler Nicole B. , Romanos Georg E. 
Published: July 2004

AbstractAim: The aim of this controlled, parallel design clinical study was to compare the healing of intrabony periodontal defects following treatment with access flap surgery with and without debridement with an Er:YAG laser.Methods: Twenty‐three patients each of whom exhibited one deep intrabony defect were randomly treated with either access flap surgery followed by root surface and defect debridement using an Er:YAG laser (KEY3®) (160 mJ, 10 Hz) (test), or with access flap surgery followed by root surface and defect debridement using hand and ultrasonic instruments (control). The following clinical parameters were recorded at baseline and at 6 months: plaque index; gingival index; bleeding on probing; probing depth (PD); gingival recession; and clinical attachment level (CAL). The primary outcome variable was CAL. No statistically significant differences between the groups were found at baseline.Results: No serious adverse events were observed after any of the treatments. The results have shown that in the test group the PD decreased from 7.8±1.3 to 4.1±1.3 mm (p<0.001) and the CAL changed from 9.8±2.9 to 7.2±2.5 mm (p<0.001). In the control group the PD decreased from 7.8±0.8 to 4.6±1.6 mm (p<0.001) and the CAL changed from 9.2±1.2 to 7.7±1.6 mm (p<0.01). The test group displayed a higher tendency for CAL gain, although this tendency did not prove to be statistically significant.Conclusion: Within the limits of the present study, it can be concluded that: (i) at 6 months following treatment both therapies led to significant improvements of the investigated clinical parameters, and (ii) an Er:YAG laser may represent a suitable alternative for defect and root surface debridement in conjuction with periodontal surgery.
The effect of a chlorhexidine regimen on de novo plaque formation
Authors: Sekino Satoshi , Ramberg Per , Guzin Uzel Naciye , Socransky Sigmund , Lindhe Jan 
Published: July 2004

AbstractObjective: To evaluate the effect of a pretreatment regimen that combined meticulous mechanical tooth cleaning with the daily use of chlorhexidine (rinse, gargle and tongue application) on de novo plaque formation and on the recolonization of various microbiological species in plaque and saliva during a 4‐day period of no oral hygiene.Material and Methods: Ten subjects aged 24–36 years with gingivitis were recruited. The study was designed as a double blind cross‐over clinical trial including two phases. Each experimental phase comprised one preparatory period of 7 days and one plaque accumulation period of 4 days. During the preparatory period, the volunteers (i) performed meticulous mechanical tooth cleaning using toothbrush and dentifrice and (ii) were, in addition, given two sessions of professional tooth cleaning (PTC) The final PTC was delivered after bacterial sampling had been made on Day 0. In the Control group, no additional plaque control measures were included. In the Test group, the participants in addition to the mechanical measures (i) rinsed twice daily, for 60 s each time with a 0.2% chlorhexidine solution, (ii) gargled twice daily for 10 s with the chlorhexidine preparation, and finally (iii) brushed the dorsum of the tongue for 60 s, twice daily, with a 1.0% chlorhexidine gel. During the 4‐day plaque accumulation period, the participants abstained from all mechanical and chemical plaque control measures. On Days 0, 1, 2 and 4 the quantity and quality of plaque formed was assessed by clinical means and by DNA probe techniques. The microbiota of the saliva was studied in samples obtained on Days 0 and 4.Results: It was demonstrated that chlorhexidine used as a mouthrinse combined with gargling and tongue application during the preparatory period significantly retarded the amount of plaque that formed on tooth surfaces during the following 4 days of no oral hygiene. Further, the number of microorganisms present in the biofilm representing Days 0, 1 and 2 of the “plaque accumulation period” was apparently affected by the use of the antiseptic. Among the microorganisms influenced by the chlorhexidine regimen, a substantial number belonged to the genus Actinomyces. It was also observed that the adjunctive use of chlorhexidine reduced the number of bacteria present in saliva at the end of the preparatory period (i.e. on Day 0). After 4 days of no oral hygiene, the microbiota of the newly formed plaque in the Test and Control groups had many features in common.Conclusion: Habitat is critical in controlling the bacterial composition of the dental biofilm. The microbiota will tend to go back to the one that is characteristic of a given subject, once chemical antimicrobial means are withdrawn.
A model of periodontitis in the rat: effect of lipopolysaccharide on bone resorption, osteoclast activity, and local peptidergic innervation
Authors: Dumitrescu Alexandrina L. , Abd El‐Aleem Seham , Morales‐Aza Begonia , Donaldson Lucy F. 
Published: July 2004

AbstractObjective: To establish and characterise a rat model of periodontitis that reiterates the features of human disease.Methods: Periodontal inflammation was induced by a single injection of 10 μg liposaccharide (LPS) (Salmonella typhimurium) in 1 μl saline into rat mandibular gingiva at the buccomesial aspect of the second molar. Animals were killed after 3, 7 and 10 days, mandibles dissected and sectioned for histological and immunocytochemical analysis.Results: LPS injection resulted in a significant gingival and periodontal inflammation with inflammatory infiltrate, apical migration of the junctional epithelium, interdental bone loss, and activation of osteoclasts at the site of injection 7 and 10 days after injection. At 10 days post injection, there was a significant trend for bone loss on both sides of the mandible. Periodontal inflammation was associated with alteration in the levels of calcitonin gene‐related peptide‐like immunoreactivity in nerve terminals innervating the inflamed gingival papilla.Conclusion: Intragingival injection of LPS in the rat provides an easily induced reproducible experimental model of periodontal inflammation that reiterates features of human disease.
High and low brushing force in relation to efficacy and gingival abrasion
Authors: Van der Weijden G. A. , Timmerman M. F. , Versteeg P. A. , Piscaer M. , Van der Velden U. 
Published: July 2004

AbstractObjectives: Does a high brushing force induce more gingival abrasion than a low (regular) brushing force? Furthermore, what is the effect of a low or high force on the efficacy?Methods: Thirty‐five non‐dental students were selected. All received an appointment prior to which they abstained from oral hygiene for at least 48 h. At baseline the teeth and surrounding tissues were disclosed using Mira‐2‐Tone® disclosing solution. Next, the examiner (PAV) evaluated the number of sites with gingival abrasion and the amount of dental plaque (Quigley & Hein) at 6 surfaces of each tooth. In the absence of this examiner, the subject's teeth were brushed by a hygienist (MP) using the Braun/Oral‐B®‐D17 oscillating rotating toothbrush. Brushing was performed in two randomly selected contra‐lateral quadrants for 60 s with either a low force (±1.5 N) or high force (±3.5 N) and in the opposing quadrants for 60 s with the alternative force. Visual feedback was given to control force. The brush was moved from the distal tooth to the central incisor perpendicular to the tooth surface with an angle of approximately 10–15° towards the gingival margin. Next, the number of sites with abrasion and the remaining plaque were assessed again.Results: The overall baseline gingival abrasion scores were 3.1 and 3.2 sites for high and low force, respectively, and increased to 5.0 and 5.9 sites respectively after brushing. There was no significant difference with respect to incidence of abrasion. At baseline, 48 h. plaque levels were 2.2. The reduction in plaque scores with the low force was 60% and with the high force 56%. This difference was significant.Conclusion: With the oscillating rotating power toothbrush (Braun/Oral‐B D17) the use of high force (±3.5 N) is less efficacious as compared to a regular low force (±1.5 N) while the incidence of gingival abrasion sites was comparable. (This study was sponsored by Gillette.)
Periodontal repair in dogs: effect of recombinant human bone morphogenetic protein‐12 (rhBMP‐12) on regeneration of alveolar bone and periodontal attachment
Authors: Wikesjö Ulf M. E. , Sorensen Rachel G. , Kinoshita Atsuhiro , Jian Li X. , Wozney John M. 
Published: July 2004

AbstractObjectives: Recombinant human bone morphogenetic protein‐2 (rhBMP‐2) has been shown to stimulate alveolar bone and cementum formation in periodontal defects but not a functionally oriented periodontal ligament (PDL). Subcutaneous and intramuscular implants of BMP‐12 have been shown to induce tendon formation and ligament‐like tissue. The objective of this study was to evaluate rhBMP‐12 for periodontal regeneration, in particular PDL formation.Methods: Six young adult Hound Labrador mongrel dogs were used. Routine supraalveolar periodontal defects were created around the mandibular premolar teeth. Three animals received rhBMP‐12(0.04 mg/ml) in an absorbable collagen sponge (ACS) carrier vs. rhBMP‐12(0.2 mg/mL)/ACS in contralateral defects. Three animals received rhBMP‐12(1.0 mg/ml)/ACS vs. rhBMP‐2(0.2 mg/ml)/ACS (total implant volume/defect ∼1 ml). The animals were euthanized 8 weeks postsurgery and block biopsies were processed for histometric analysis.Results: Bone regeneration appeared increased in sites receiving rhBMP‐2/ACS compared to sites receiving rhBMP‐12/ACS. Cementum regeneration was similar comparing sites implanted with rhBMP‐2/ACS to sites implanted with rhBMP‐12/ACS. In contrast, sites receiving rhBMP‐12/ACS exhibited a functionally oriented PDL bridging the gap between newly formed bone and cementum whereas this was a rare observation in sites receiving rhBMP‐2/ACS. Ankylosis appeared increased in sites receiving rhBMP‐2/ACS compared to those receiving rhBMP‐12/ACS.Conclusions: The outcomes of this study suggest that rhBMP‐12 may have significant effects on regeneration of the PDL. Additional preclinical evaluation is needed to confirm these initial observations prior to clinical application.
Matrix metalloproteinases, their physiological inhibitors and osteoclast factors are differentially regulated by the cytokine profile in human periodontal disease
Authors: Garlet Gustavo P. , Martins Walter , Fonseca Benedito A.L. , Ferreira Beatriz R. , Silva João S. 
Published: July 2004

AbstractObjective: Inflammatory reactions raised in response to periodontopathogens are thought to trigger pathways of periodontal tissue destruction. We therefore investigated the expression of matrix metalloproteinases (MMPs) and the osteoclastogenic factor receptor activator of nuclear factor‐κB ligand (RANKL), their respective tissue inhibitors of metalloproteinases (TIMPs) and osteoprotegerin (OPG) in different forms of human periodontal diseases (PDs), and the possible correlation with the expression of inflammatory and regulatory cytokines.Material and Methods: Quantitative polymerase chain reaction (real‐time PCR) was performed with gingival biopsies mRNA from aggressive (AP) and chronic periodontitis (CP) patients.Results: Periodontitis patients exhibit higher expression of all analyzed factors when compared with healthy tissues. The expression of MMPs and RANKL were similar in AP and CP, as well as the expression of TNF‐α. On the other hand, the expression of TIMPs and OPG was higher in CP, and was associated with lower IFN‐γ and higher IL‐10 expression, compared with AP.Conclusion: It is possible that the pattern of cytokines expressed determines the stable or progressive nature of the lesions and regulates the severity of PD, driving the balance between MMPs and TIMPs, RANKL and OPG expression in the gingival tissues controlling the breakdown of soft and bone tissues and, consequently, the disease severity.