bluuebunny/crossref_metadata_2025 huggingface dataset:
Relative Contribution of Potential Modes of Surface Dust Lead Contamination in the Homes of Boatyard Caulkers
Authors: Untimanon Orrapan , Geater Alan , Chongsuvivatwong Virasakdi , Saetia Wiyada , Verkasalo Pia K
Published: March 2012

Relative Contribution of Potential Modes of Surface Dust Lead Contamination in the Homes of Boatyard Caulkers: Orrapan UNTIMANON, et al. Bureau of Occupational and Environmental Diseases, Ministry of Public Health, Thailand—

Objectives

The aim of this study was to quantify the relative contributions to surface lead contamination of boat‐caulkers' houses of three contamination modes, namely “take‐home” lead from the caulker, “natural” spatial dispersal from boatyard to household and “redistribution” of accumulated lead‐laden dust within the house.

Methods

Boat‐caulkers' houses situated in areas surrounding boat repair yards were recruited. Caulkers' houses that were located close together were divided into location‐matched pairs, within which one was randomly assigned to be given a cleaning and designated a CL house, and the other was to be left uncleaned and designated a NCL house. Geographically isolated caulker's houses were randomly assigned to one of the two categories. The nearest non‐boatyard worker's house (NB) was additionally recruited for each set. The surface lead loading rate (SLLR), defined as the mass of lead deposited in dust per unit area of surface per unit time, was measured over a period of 3 mo in all houses, and the data were modeled using linear mixed effects regression.

Results

Adjusted values of SLLR differed only slightly between CL and NCL houses (0.96 to 1.02 times) but were between 1.65 and 2.03 times higher in CL and NCL houses than in NB houses depending on proximity to the boatyard and between 2.12 and 2.61 times higher in houses within one km of a boatyard than in more distant houses depending on category of house.

Conclusions

Newly deposited dust lead likely resulted from the take‐home and spatial dispersion modes. The contribution of redistribution is very small.
Microbiological and Clinical Monitoring of Non‐Localized Juvenile Periodontitis in Young Adults: A Report of 11 Cases
Authors: van Steenbergen T. J. Martijn , van der Veiden Ubele , Abbas Frank , de Graaff Johannes
Published: March 2012

It has been shown that patients with localized juvenile Periodontitis (LJP) often harbor Actinobacillus actinomycetemcomitans in the subgingival area. However, little is known of the oral microflora in non‐LJP juvenile Periodontitis patients with less extensive disease. The purpose of this study was to describe the microflora and clinical parameters of young adults with minor to moderate periodontitis during treatment for a period of 1 year. Eleven patients 15 to 16 years of age were studied. All of them had 4 to 8 mm loss of attachment at minimally one site, but the typical clinical description of localized juvenile periodontitis was an exclusion criterion in this study. Microbiological examination of the deepest periodontal pocket and of the tongue revealed that 6 patients harbored Actinobacillus actinomycetemcomitans and 5 harbored Porphyromonas gingivalis. Almost all subjects showed relatively high proportions of Prevotella intermedia, Campylobacter rectus, motile organisms, and spirochetes. On the basis of clinical and microbiological parameters the 11 patients could be assigned to 1 of 2 groups. Six cases had moderate periodontal breakdown with loss of attachment at 7 to 44 sites. All harbored A. actinomycetemcomitans and 5 of them P. gingivalis. These 6 cases responded relatively well to initial treatment despite the continued presence of A. actinomycetemcomitans. The other group consisted of 5 cases with relatively minor periodontal breakdown; i.e, 1 or 2 sites with 4 to 6 mm loss of attachment. Neither A. actinomycetemcomitans nor P. gingivalis was detected in the deepest pocket of these patients. All 5 responded well to initial treatment. It can be hypothesized that the subgingival presence of A. actinomycetemcomitans in non‐LJP patients is not predictive for a poor response to initial treatment. Therefore, recognition and treatment of A. actinomycetemcomitans associated periodontitis, if diagnosed in an early stage, may be possible to treat with conventional mechanical periodontal treatment. It remains to be determined if the presence of A. actinomycetemcomitans in these patients is a risk factor for further breakdown. J Periodontol 1993;64:40–47.
Abnormal Proportion of γδ T Cells in Peripheral Blood Is Frequently Detected in Patients With Periodontal Disease
Authors: Nagai Atsushi , Takahashi Keiso , Sato Nobuhiko , Matsuo Yoshinobu , Minowada Jun , Kurihara Hidemi , Murayama Yoji
Published: March 2012

The proportions of γδ T cells in the peripheral blood of 8 early‐onset periodontitis (EOP) patients, 8 later‐onset periodontitis (LOP) patients, and of 17 healthy subjects (HS) were assessed by immunofluorescence assay using an anti‐pan γδ T cell monoclonal antibody (TCR‐81) to study the population attributes of peripheral blood γσ T cells in patients with periodontal disease. The distribution of the proportions of γδ T cells in both EOP and LOP patients was found to be one and one half times broader than that in the HS; however, there was no significant difference in the proportion of γδ T cells between each group. An abnormally high proportion of peripheral blood γδ T cells in pan T cells (>9.90%) was observed in 37.5% of both the EOP patients and the LOP patients. An abnormally low proportion (<5.57%) was observed in 50% of the EOP patients and in 25% of the LOP patients. The higher occurrences of the high or low γδ T cell proportions were significant between EOP and HS, and between EOP + LOP and HS. There was no correlation between the proportion of γδ T cells and age or the clinical parameters of periodontal status. It was concluded that an abnormal proportion of γδ T cells is frequently detected in patients with periodontal disease. These findings are consistent with the proposed role of the γδ T cells for playing a unique role as a first line defense against infections at body surfaces. J Periodontol 1993; 64:963–967.
Microbial Composition and Pattern of Antibiotic Resistance in Subgingival Microbial Samples From Patients With Refractory Periodontitis
Authors: Listgarten Max A. , Lai Chern‐Hsiung , Young Virginia
Published: March 2012

A series of 993 subgingival microbial samples sent to a diagnostic microbiology laboratory included 196 samples that could be identified as compatible with a clinical diagnosis of refractory or recurrent periodontitis. In descending order of prevalence the associated microbiota included Bacteroides forsythus (84%), spirochetes (83%), motile rods (76%), Fusobacterium species (68%), Porphyromonas gingivalis (63%), Campylobacter rectus (47%), Capnocytophaga species (38%), Prevotella intermedia (23%), Peptostreptococcus micros (18%), Actinobacillus actinomycetemcomitans (16%), Candida (14%), enteric rods (9%), Staphylococcus species, not including aureus (5.6%). Eikenella corrodens (3%), Staphylococcus aureus (1.5%), and Enterococcus species (<1%). Antibiotic resistance to tetracycline, penicillin G, or metronidazole was particularly noticeable for enteric rods, Fusobacterium species, Capnocytophaga species, Staphylococcus, and Actinobacillus actinomycetemcomitans. It was largely absent for Campylobacter rectus. No antibiotic sensitivity data were obtained for Porphyromonas gingivalis or Bacteroides forsythus, as these species were detected by immunofluorescence. The results indicate that a substantial number of microorganisms associated with refractory Periodontitis are variably resistant to commonly‐used antibiotics. Diagnostic microbiology must be considered an essential adjunct to the therapist faced with periodontal lesions refractory to conventional treatment. J Periodontol 1993; 64:155–161.
Histologic Evaluation of Periodontal Attachment Apparatus Following the Insertion of a Biodegradable Copolymer Barrier in Humans
Authors: Vuddhakanok Suchada , Solt Charles W. , Mitchell John C. , Foreman Dennis W. , Alger Fred A.
Published: March 2012

The purpose of this study was to histologically evaluate the effectiveness of polylactide:polyglycolide 50:50 (DL‐PLGA) as a barrier to prevent epithelial migration and to promote new connective tissue attachment. Mucoperiosteal flaps were performed on 17 human teeth. DL‐PLGA membrane was placed over the roots and alveolar bone. DLPLGA was not placed over control teeth. Ninety days following surgery, block sections were obtained and processed for histologic evaluation. All specimens revealed a mean length of epithelial attachment within physiologic limits and recession of the gingival margin. There was little or no reattachment of the connective tissue. It is concluded that this copolymer barrier did not prevent epithelial migration nor enhance connective tissue attachment to human roots with severe horizontal bone loss and active periodontal disease. J Periodontol 1993;64:202–210.
Efficacy of 5 Machining Instruments in Scaling of Molar Furcations
Authors: Takacs Vincent J. , Lie Tryggve , Perala Dennis G. , Adams Donald F.
Published: March 2012

The scaling efficacy of machining instruments was studied in the furcations of 100 extracted molars. The molars were divided into 5 groups with similar furcation anatomy, painted with artificial calculus, partly submerged in stone blocks, and the furcation entrances covered with a heavy rubber dam material. Ten mandibular and 10 maxillary molars were scaled by an experienced operator with each of the following instruments/inserts: ultrasonic instrument with either a prototype ball point insert or with a new pointed insert; ultrasonic instrument with a ball point insert; reciprocating handpiece with new inserts for furcations; and a sonic sealer with a universal insert. The molar groups were coded and graded in a stereomicroscope by 2 independent examiners, and the rankings were tested with the Kruskal‐Wallis test and the multiple comparisons between treatments test. The results revealed statistically significant differences between the instruments, as well as between different topographical areas of the furcations. The sonic sealer with a universal insert and the ultrasonic instrument with ball point inserts were significantly more efficient (P < 0.05) than the reciprocating handpiece with inserts in most of the areas studied. For mandibular molars, significantly better results (P < 0.05) were obtained for lingual furcation entrances than for furcation roofs. For maxillary molars, significantly better results (P < 0.05) were obtained for distal and buccal entrance areas than for furcation roofs and inside of mesial roots. The present study may give some guidance to the practitioner in choosing machining instruments for furcation cleaning as well as identifying the most difficult topographical areas to instrument. J Periodontol 1993; 64:228–236.
Development of the Murine Periodontium. II. Role of the Epithelial Root Sheath in Formation of the Periodontal Attachment
Authors: MacNeil R. Lamont , Thomas Huw F.
Published: March 2012

Experimental manipulation of the developing murine tooth germ has provided evidence that basement membrane components on the forming root surface are involved in early periodontal attachment formation. The purpose of this investigation was to determine the role of epithelial root sheath (ERS) cells in murine cementogenesis and periodontal ligament formation using tissue separation and recombination techniques. Root dentin specimens, with and without root‐associated basement membrane components (D + RBM or D − RBM), were recombined with dental sac in the presence or absence of ERS. Recombinations were cultured for 2 weeks, harvested, and examined by light, electron, and immunofluorescence microscopy. Mineralized tissue formed in all tissue recombinations. However, when ERS was included in recombinations between D + RBM and dental sac, 25% of recombinations formed a periodontal ligament with fibrous attachment of the root specimen to adjacent bone. These results support the hypothesis that root and periodontal ligament formation is influenced by epithelio‐mesenchymal interactions and further support a key role for ERS in these processes. J Periodontol 1993;64:285–291.
Hydroxyproline and Total Protein Levels in Gingiva and Gingival Crevicular Fluid in Patients With Juvenile, Rapidly Progressive, and Adult Periodontitis
Authors: Akalin F. Alev , Şengün Dilek , Eratalay Kenan , Renda Nurten , Çağlayan Gürhan
Published: March 2012

The aim of this study was to compare hydroxyproline (Hyp) and total protein levels both in the gingiva and gingival crevicular fluid (GCF) from juvenile (JP), rapidly progressive (RPP), and adult periodontitis (AP) patients and periodontally healthy controls (C). A total of 60 individuals, 15 from each group, were studied. GCF was obtained before gingival sampling. Clinical measurements were recorded. The gingival samples were harvested by full thickness flap operation from patients and immediately after the extraction of the teeth for orthodontic reasons from controls. The samples were analyzed biochemically. GCF Hyp levels were significantly higher in the AP group than those of the RPP and C groups. The strong positive correlations between gingival and GCF Hyp levels were determined in the disease groups. Total protein levels in both the gingiva and GCF were significantly higher in disease groups. However, the differences between the disease groups were not statistically significant. Correlations between the clinical parameters and Hyp levels in gingiva and GCF were determined. The findings indicate that Hyp and total protein levels both in the gingiva and GCF appeared to be increased in the disease groups. These findings suggest that both the synthesis and degradation of collagen and total protein are elevated in periodontal disease. However, our findings do not support the concept that measurement of either Hyp or total protein levels in gingiva or GCF is a suitable or reliable criterion in determination of disease activity. J Periodontol 1993; 64:323–329.
Progression of Periodontal Disease in HIV Seropositive Patients
Authors: Yeung Stephen C. H. , Stewart Graeme J. , Cooper David A. , Sindhusake Doungkamol
Published: March 2012

Data from cross‐sectional studies suggest that periodontitis in HIV‐infected patients is a more destructive form of disease in contrast to the slowly progressing form of adult periodontitis in the general population. We studied prospectively over an 18‐month period 30 HIV infected, but asymptomatic, patients and compared the rate of periodontal attachment loss with that of a healthy control group (n = 10) matched for age and plaque index. Every 6 months, each subject was assessed for their clinical status by a physician and CD4+ cell count determined. The proliferative response of peripheral blood lymphocytes was determined by in vitro cultures with PHA and Con A. The periodontal health status was assessed by scoring with plaque index (PI), gingival index (GI), and periodontal disease index (PDI). The control subjects were assessed for periodontal status only. Of the 30 HIV‐positive patients whose data were analyzed 14 received Zidovudine (AZT) while the remaining 16 did not. There was no correlation between any clinical parameter measured and periodontal status as determined by PI or GI. However, a significant difference in the change of periodontal disease index (PDI) was observed between the HIV‐infected and control groups (P = 0.005). We concluded that HIVinfected patients with pre‐existing Periodontitis tend to experience a greater rate of attachment loss over time compared with controls. J Periodontol 1993; 64:651–657.
Comparative Analysis Between a Modified Ultrasonic Tip and Hand Instruments on Clinical Parameters of Periodontal Disease
Authors: Copulos Thomas A , Low Samuel B. , Walker Clay B. , Trebilcock Yvonne Y. , Hefti Arthur F.
Published: March 2012

The goal of this study was to determine whether an ultrasonic scaler with a modified tip is as effective as a curet in providing supportive periodontal treatment for patients, based on clinical parameters of periodontal disease. Nine patients with 10 sites exhibiting probing pocket depth ≥ 3 mm were treated at 0, 90, and 180 days in a single‐blind, split‐mouth design for supportive periodontal treatment with either Gracey curets (GC) or an ultrasonic scaler with a modified tip (MU). Clinical parameters included plaque index, gingival index, bleeding on probing, darkfield microscopy, and clastase presence. Probing pocket depths and attachment levels were measured using an electronic probe. Measurements of clinical parameters were taken at 0, 14, 45, 90, 135, and 180 days. The results showed that treatment with MU was as effective as treatment with GC in all clinical parameters measured. Both treatment modalities were effective in reducing the elastase levels. Instrumentation time was significantly reduced with the MU (3.9 minutes vs. 5.9 minutes, P <0.05). The MU instrument effectively reduced the microbial environment in a significantly shorter time as compared to GC. J Periodontol 1993;64:694– 700.
The Rate of Periodontal Attachment Loss in Subjects With Established Periodontitis
Authors: Machtei Eli E. , Norderyd Johanna , Koch Gary , Dunford Robert , Grossi Sara , Genco Robert J.
Published: March 2012

A stepwise approach to determine attachment level changes was utilized to assess the nature of progression of periodontal disease. Following initial screening, 51 subjects with established Periodontitis were monitored quarterly for 9 more months. Probing depth (PD) and relative attachment level (RAL) were recorded using an automated, pressure sensitive probe system. To establish intra‐examiner error, repeated measurements were performed for all sites at the final visit. An overall standard deviation (SD) for RAL repeated measurements was initially calculated (0.76 mm) using all 6,935 double measurements. Sites were sorted by factors which contribute to the error of attachment level measurements; i.e., pocket depth (shallow, moderate, deep), tooth type (molar, nonmolar) and location (buccal, lingual). Data were sorted by the above 12 groups, and SD for repeated measurements was calculated separately for them. The ratio between these SD and the overall SD served as the corrective factor. Each patient's initial threshold (2 SD) was multiplied by these corrective factors thus resulting in 12 thresholds for each subject. Next, linear, exponential and logarithmic regression models were tested for each site, and the regression model showing the highest R value was chosen for that site. AL changes were tested against the patient's threshold for that site. Sites with attachment loss exceeding the threshold were deemed active. Five hundred eighty‐one sites (8.3%) exhibited attachment loss exceeding the various thresholds. Of these, linear progression occurred in 195, logarithmic in 224, and exponential in 162 sites. Individual patient's attachment loss ranged from 0.6 to 19.4% of all sites. Mean AL change was 0.2 mm; however, deep sites had significantly (P < 0.001) greater mean loss (1.03 mm) compared to moderate (0.34 mm) and shallow (0.1 mm) sites. Twenty‐two subjects exhibited a small percentage of losing sites (<5%), and 16 patients had moderate (5 to 11%) while 13 patients exhibited massive losing sites (>11%). Sites with deep pockets had experienced greater percentages of losing sites (16.3%) compared to 7.7% and 8.8% for the shallow and moderate sites respectively (P ≤0.001). Patients with a small percentages of losing sites experienced an overall net attachment gain (0.078 mm) compared to mean AL loss of 0.357 mm and 0.581 mm for the moderate and massive groups respectively (P <0.05). These results suggest that regression models and individualized thresholds can be utilized to produce site‐based data analysis to determine AL changes. Furthermore, the rapid AL changes in approximately 20% of the subjects suggest that they may represent different phases or possibly different forms of periodontal disease. Various risk factors or pathogenic microorganisms may be associated with these different patterns which, whenever found, could help to better understand the variability of periodontal disease. J Periodontol 1993; 64:713–718.
Specific Antibodies and Their Potential Role in Periodontal Diseases
Authors: McArthur William P. , Clark William B.
Published: March 2012

Periodontal diseases are thought to result from inflammatory responses to bacterial challenges in the gingival crevicular area. Antibodies are a major host‐protective mechanism in many bacterial infections. Consequently, the antibody responses to suspected periodontal pathogenic bacteria have been extensively measured as to their relationship to diseases and specificity for suspected pathogens associated with progressing disease sites. Recently, studies on the bacterial immunogen characterization, antibodysubclass identification, and antibody biological capabilities have been reported. Although increased antibody levels to certain suspected periodontal pathogens were associated with periodontal diseases in humans, little evidence exists as to the role of these antibodies in the infectious process. In vivo experiments in animals indicated that specific antibodies against certain suspected periodontal pathogens were associated with suppression of bacterial colonization, limiting the spread of infection, and a decrease in alveolar bone loss. However, in vitro as well as in vivo experiments suggested that phagocytic cells are required for efficient bactericidal activity of antibodies and that the presence of other sensitized immune cells may either have inhibited or enhanced the infectivity of certain periodontal pathogens. Possible explanations for the observed inconsistencies are presented and the potential for utilization of specific anti‐periodontal pathogen responses in the understanding and prevention of diseases is discussed. J Periodontol 1993; 64:807– 818.
Small Versus Large Particles of Demineralized Freeze‐Dried Bone Allografts in Human Intrabony Periodontal Defects
Authors: Fucini Stephen E. , Quintero George , Gher Marlin E. , Black Barbara S. , Richardson A. Charles
Published: March 2012

Various particle sizes of demineralized freeze‐dried bone allograft (DFDBA) are currently used to treat patients with periodontal osseous defects. However, the effect of particle size on the healing of human intrabony periodontal defects is unknown since there have been no direct clinical comparisons. The purpose of this study was to compare the bony defect resolution obtained using two different particle size ranges of DFDBA. Cortical bone from a single donor was processed and ground to final particle sizes of 250μ to 500μ or 850μ to 1,000μ using an analytic mill. Paired interproximal intrabony periodontal defects in 11 patients were grafted with DFDBA. Soft and hard tissue measurements were made using an electronic constant‐force probe at the initial and reentry surgeries. Treated sites in 10 patients were reevaluated by reentry approximately 6 months postoperatively. Mean bony defect fill was 1.66 mm for the large particle group and 1.32 mm for the small particle group. There was no statistically significant difference in bony fill between defects grafted with the different particle sizes of DFDBA when used in humans. J Periodontol 1993; 64:844–847.
Comparative Histochemical and Biochemical Studies of Mast Cell Tryptase in Human Gingiva
Authors: Kennett Craig N. , Cox Stephen W. , Eley Barry M. , Osman Ibrahim A.R.M.
Published: March 2012

Tryptase‐like activity has previously been identified biochemically in gingival homogenates and gingival crevicular fluid (GCF) using substrates linked to the 7‐amino4‐trifluoromethyl coumarin (AFC) leaving group. In the present study, activity was demonstrated histochemically in tissue sections with analogous 4‐methoxy‐2‐naphthylamide (MNA) substrates. Z‐Ala‐Ala‐Lys‐MNA and D‐Val‐Leu‐Arg‐MNA were the most sensitive substrates. Comparison of staining patterns with the MNA substrates and toluidine blue indicated that enzyme activity was localized to mast cell secretory granules. Most stained cells were in the lamina propria, but a few were in the epithelium. The number of stained cells was somewhat greater in inflamed tissue from chronic Periodontitis patients than in healthy tissue from controls. However, hardly any staining was seen in inflamed granulomatous tissue. Using high‐salt buffer containing heparin, it was possible to extract enzyme activity from tissue sections for biochemical analysis with corresponding AFC substrates. Inhibitors gave similar results in the biochemistry and histochemistry. The inhibitor response and pH profile of the enzyme were the same as that found earlier with gingival homogenates and GCF and were again consistent with mast cell tryptase. The enzyme may have a role in the pathology of chronic Periodontitis. J Periodontol 1993; 64:870–877.
Resting-State Brain Networks in Type 1 Diabetic Patients With and Without Microangiopathy and Their Relation to Cognitive Functions and Disease Variables
Authors: van Duinkerken Eelco , Schoonheim Menno M. , Sanz-Arigita Ernesto J. , IJzerman Richard G. , Moll Annette C. , Snoek Frank J. , Ryan Christopher M. , Klein Martin , Diamant Michaela , Barkhof Frederik
Published: March 2012

Cognitive functioning depends on intact brain networks that can be assessed with functional magnetic resonance imaging (fMRI) techniques. We hypothesized that cognitive decrements in type 1 diabetes mellitus (T1DM) are associated with alterations in resting-state neural connectivity and that these changes vary according to the degree of microangiopathy. T1DM patients with (MA+: n = 49) and without (MA−: n = 52) microangiopathy were compared with 48 healthy control subjects. All completed a neuropsychological assessment and resting-state fMRI. Networks were identified using multisubject independent component analysis; specific group differences within each network were analyzed using the dual-regression method, corrected for confounding factors and multiple comparisons. Relative to control subjects, MA− patients showed increased connectivity in networks involved in motor and visual processes, whereas MA+ patients showed decreased connectivity in networks involving attention, working memory, auditory and language processing, and motor and visual processes. Better information-processing speed and general cognitive ability were related to increased degree of connectivity. T1DM is associated with a functional reorganization of neural networks that varies, dependent on the presence or absence of microangiopathy.
Protein Kinase Cβ Phosphorylates Occludin Regulating Tight Junction Trafficking in Vascular Endothelial Growth Factor–Induced Permeability In Vivo
Authors: Murakami Tomoaki , Frey Tiffany , Lin Chengmao , Antonetti David A.
Published: March 2012

Vascular endothelial growth factor (VEGF)–induced breakdown of the blood-retinal barrier requires protein kinase C (PKC)β activation. However, the molecular mechanisms related to this process remain poorly understood. In this study, the role of occludin phosphorylation and ubiquitination downstream of PKCβ activation in tight junction (TJ) trafficking and endothelial permeability was investigated. Treatment of bovine retinal endothelial cells and intravitreal injection of PKCβ inhibitors as well as expression of dominant-negative kinase was used to determine the contribution of PKCβ to endothelial permeability and occludin phosphorylation at Ser490 detected with a site-specific antibody. In vitro kinase assay was used to demonstrate direct occludin phosphorylation by PKCβ. Ubiquitination was measured by immunoblotting after occludin immunoprecipitation. Confocal microscopy revealed organization of TJ proteins. The results reveal that inhibition of VEGF-induced PKCβ activation blocks occludin Ser490 phosphorylation, ubiquitination, and TJ trafficking in retinal vascular endothelial cells both in vitro and in vivo and prevents VEGF-stimulated vascular permeability. Occludin Ser490 is a direct target of PKCβ, and mutating Ser490 to Ala (S490A) blocks permeability downstream of PKCβ. Therefore, PKCβ activation phosphorylates occludin on Ser490, leading to ubiquitination required for VEGF-induced permeability. These data demonstrate a novel mechanism for PKCβ targeted inhibitors in regulating vascular permeability.
Effect of Composite Resin Contamination with Powdered and Unpowdered Latex Gloves on Its Shear Bond Strength to Bovine Dentin
Authors: Oskoee SS , Navimipour EJ , Bahari M , Ajami AA , Oskoee PA , Abbasi NM
Published: March 2012

The aim of the present study was to evaluate the effect of composite resin contamination with powdered and unpowdered latex gloves on the shear bond strength of etch-and-rinse and two-step self-etch adhesive systems. Standard flat dentin surfaces were prepared on the facial aspect of 120 bovine incisors and randomly assigned into two (n=60) groups: group 1: Single Bond (SB), group 2: Clearfil SE Bond (CSE). Furthermore, each group was randomly subdivided into three (n=20) based on the type of composite contamination (without contamination, contamination with powdered latex gloves, and contamination with unpowdered latex gloves). The adhesives were applied and resin composite bonded to the dentin. After thermocycling, the specimens were subjected to a shear bond strength test. Two-way analysis of variance (ANOVA) and a post hoc Bonferroni test were used for statistical analysis. One-way ANOVA was used to compare shear bond strength values in each group. Statistical significance was set at p < 0.02. Two-way ANOVA showed that the shear bond strength was significantly influenced by the type of composite surface contamination (p=0.001). In the SB group there were no significant differences between different surface treatments (p=0.08). In the CSE group a significant difference was observed between the subgroup without contamination and the subgroup with powdered latex glove contamination (p=0.01); however, no significant differences were observed between the other subgroups.
Exponentially Convergent Functional-discrete Method for Eigenvalue Transmission Problems with a Discontinuous Flux and the Potential as a Function in the Space L_1
Authors: Makarov Volodymyr , Rossokhata Nataliia , Dragunov Denys
Published: March 2012

Based on the functional-discrete technique (FD-method), an
algorithm for solving eigenvalue transmission problems with a
discontinuous flux and the integrable potential is developed. The
case of the potential as a function belonging to the functional
space L_1 is studied for both linear and nonlinear eigenvalue
problems. The sufficient conditions providing superexponential
convergence rate of the method were obtained. Numerical examples are
presented to support the theory. Based on the numerical examples and
the convergence results, conclusion about analytical properties of
eigensolutions for nonself-adjoint differential operators is
made.
A FETI-DP Method for Crouzeix-Raviart Finite Element Discretizations
Authors: Marcinkowski Leszek , Rahman Talal
Published: March 2012

This paper is concerned with the construction and analysis of a parallel preconditioner
for a FETI-DP system of equations arising from the nonconforming Crouzeix-Raviart finite
element discretization of a model elliptic problem of second order with discontinuous coefficients.
We show that the condition number of the preconditioned problem is independent of the coefficient jumps,
and the preconditioner is quasi optimal.
Error Estimates for Approximations of American Put Option Price
Authors: Šiška David
Published: March 2012

Finite difference approximations to multi-asset American put option price are considered.
The assets are modelled as a multi-dimensional diffusion process with variable drift and volatility.
Approximation error of order one quarter with respect to the time discretisation parameter and one
half with respect to the space discretisation parameter is proved by reformulating the corresponding optimal stopping problem
as a solution of a degenerate Hamilton-Jacobi-Bellman equation. Furthermore, the error arising from restricting the discrete
problem to a finite grid by reducing the original problem to a bounded domain is estimated.
Dosimetry of two new interstitial brachytherapy sources
Authors: Saidi Pooneh , Sadeghi Mahdi
Published: March 2012

Dosimetry of two new interstitial brachytherapy sources

With increased demand for low 103Pd (palladium) seed sources, to treat prostate and eye cancers, new sources have been designed and introduced. This article presents the two new palladium brachytherapy sources, IR03-103Pd and IR04-103Pd that have been developed at Nuclear Science and Technology Research Institute. The dosimetry parameters such as the dose rate constant Λ, the radial dose function g(r), and the anisotropy function F(r,θ), around the sources have been characterized using Version 5 Monte Carlo radiation transport code in accordance with the update AAPM Task Group No. 43 report (TG-43U1). The results indicated the dose rate constant of 0.689±0.02 and 0.667±0.02 cGy h-1 U-1 for the IR03-103Pd and IR04-103Pd sources respectively, which are in acceptable agreement with other commercial seeds. The calculated results were compared with published results for those of other source manufacturers. However, they show an acceptable dose distribution, using for clinical applications is pending experimental dosimetry.
DAC Testing Using Impulse Signals
Authors: Vedral Josef , Fexa Pavel
Published: March 2012

DAC Testing Using Impulse Signals

The Multi-Tone (MT) signal with uniform amplitudes can be used for DAC testing. This paper shows an easier way to generate a MT signal using several impulse signals. The article also analyzes qualities of methods for testing the dynamic parameters of Digital to Analog Converters using an impulse signal. The MT, Damped Sine Wave (DSW) and Sinx/x (SINC) signals will be used as the source for these tests. The Effective Number of Bits (ENOB) and Signal to noise and distortion (SINAD) are evaluated in the frequency domain and they are modified using theCrest Factor(CF) correction and compared with the standard results of the Sine Wave FFT test. The first advantage of the test using an impulse signal is that you need fewer input parameters to create the band signal for testing the DAC. The second one is to reduce the testing time using a band signal in comparison with multiple tests using a single sine wave.
Visibility, Usability and Accessibility of Polish E-Commerce Websites From the B2C Sector
Authors: Gąsiorkiewicz Artur
Published: March 2012

Visibility, Usability and Accessibility of Polish E-Commerce Websites From the B2C Sector

In the time of rapid development of Internet technologies and changing competitive environment, one of the most significant ways of creation of the e-commerce endeavor value is the increase of the incoming traffic of the internet website and the level of its conversion into business goals. Undertaking activities form the scope of internet marketing and increase of the usability and accessibility of websites are supporting this cause. However, this issues being broadly described in the literature they still have limited applications in business practice. The article presents the most important factors influencing the scope and characteristics of internet traffic that depends on the internet website owners. Issues are illustrates with research of listed factors that were performed on selected e-commerce systems from the B2C sector in Poland.
Construction of Estimates in the Choice of Alternative Solutions by Using the Fuzzy Utilities
Authors: Chernov Vladimir , Dorokhov Oleksandr , Malyaretz Ludmila
Published: March 2012

Construction of Estimates in the Choice of Alternative Solutions by Using the Fuzzy Utilities

The problem of multi-criteria choice of alternatives with accounting the multiple stakeholders' preferences has been considered. The model for solution with the composition of fuzzy sets has been described. The mathematical formulation and justification of the solution using a fuzzy utility functions is given. Corresponding numerical calculations and graphic example are presented.
Antihyperglycemic and Antioxidative Effects of Hydroxyethyl Methylcellulose (HEMC) and Hydroxypropyl Methylcellulose (HPMC) in Mice Fed with a High Fat Diet
Authors: Ban Su Jeong , Rico Catherine W. , Um In Chul , Kang Mi Young
Published: March 2012

The effect of dietary feeding of hydroxyethyl methylcellulose (HEMC) and hydroxypropyl methylcellulose (HPMC) on the glucose metabolism and antioxidative status in mice under high fat diet conditions was investigated. The mice were randomly divided and given experimental diets for six weeks: normal control (NC group), high fat (HF group), and high fat supplemented with either HEMC (HF+HEMC group) or HPMC (HF+HPMC group). At the end of the experimental period, the HF group exhibited markedly higher blood glucose and insulin levels as well as a higher erythrocyte lipid peroxidation rate relative to the control group. However, diet supplementation of HEMC and HPMC was found to counteract the high fat-induced hyperglycemia and oxidative stress via regulation of antioxidant and hepatic glucose-regulating enzyme activities. These findings illustrate that HEMC and HPMC were similarly effective in improving the glucose metabolism and antioxidant defense system in high fat-fed mice and they may be beneficial as functional biomaterials in the development of therapeutic agents against high fat diet-induced hyperglycemia and oxidative stress.
Exact Solution of a Constraint Optimization Problem for the Thermoelectric Figure of Merit
Authors: Seifert Wolfgang , Pluschke Volker
Published: March 2012

In the classical theory of thermoelectricity, the performance integrals for a fully self-compatible material depend on the dimensionless figure of merit zT. Usually these integrals are evaluated for constraints z = const. and zT = const., respectively. In this paper we discuss the question from a mathematical point of view whether there is an optimal temperature characteristics of the figure of merit. We solve this isoperimetric variational problem for the best envelope of a family of curves z(T)T.
A Pro-Drug Approach for Selective Modulation of AI-2-Mediated Bacterial Cell-to-Cell Communication
Authors: Guo Min , Gamby Sonja , Nakayama Shizuka , Smith Jacqueline , Sintim Herman O.
Published: March 2012

The universal quorum sensing autoinducer, AI-2, is utilized by several bacteria. Analogs of AI-2 have the potential to modulate bacterial behavior. Selectively quenching the communication of a few bacteria, in the presence of several others in an ecosystem, using analogs of AI-2 is non-trivial due to the ubiquity of AI-2 processing receptors in many bacteria that co-exist. Herein, we demonstrate that when an AI-2 analog, isobutyl DPD (which has been previously shown to be a quorum sensing, QS, quencher in both Escherichia coli and Salmonella typhimurium) is modified with ester groups, which get hydrolyzed once inside the bacterial cells, only QS in E. coli, but not in S. typhimurium, is inhibited. The origin of this differential QS inhibition could be due to differences in analog permeation of the bacterial membranes or ester hydrolysis rates. Such differences could be utilized to selectively target QS in specific bacteria amongst a consortium of other species that also use AI-2 signaling.
Homologies of the flower and inflorescence in the early‐divergent grass Anomochloa (Poaceae)
Authors: Sajo M. Graça , Pabón‐Mora Natalia , Jardim Jomar , Stevenson Dennis W. , Rudall Paula J.
Published: March 2012

• Premise of the study: The grass subfamily Anomochlooideae is phylogenetically significant as the sister group to all other grasses. Thus, comparison of their structure with that of other grasses could provide clues to the evolutionary origin of these characters.

• Methods: We describe the structure, embryology, and development of the flower and partial inflorescence of the monotypic Brazilian grass Anomochloa marantoidea. We compare these features with those of other early‐divergent grasses such as Pharus and Streptochaeta and closely related Poales such as Ecdeiocolea.

• Key results: Anomochloa possesses several features that are characteristic of Poaceae, notably a scutellum, a solid style, reduced stamen number, and an ovary with a single ovule that develops into a single indehiscent fruit. Interpretation of floral patterning in Anomochloa is problematic because the ramification pattern of the florets places the bracts and axes in unusual positions relative to the primary inflorescence axis. Our study indicates that there is a single abaxial carpel in Anomochloa, probably due to a cryptic type of pseudomonomery in Anomochloa that resembles the pseudomonomery of other grasses. On the other hand, the Anomochloa flower differs from the “typical” grass flower in lacking lodicules and possessing four stamens, in contrast with the tristaminate condition that characterizes many other grasses.

• Conclusions: Using the median part of the innermost bract as a locator, we tentatively homologize the inner bract of the Anomochloa partial inflorescence with the palea of other grasses. In this interpretation, the pattern of monosymmetry due to stamen suppression differs from that of Ecdeiocolea.
Trait convergence and plasticity among native and invasive species in resource‐poor environments
Authors: Drenovsky Rebecca E. , Khasanova Albina , James Jeremy J.
Published: March 2012

•Premise of study:Functional trait comparisons provide a framework with which to assess invasion and invasion resistance. However, recent studies have found evidence for both trait convergence and divergence among coexisting dominant native and invasive species. Few studies have assessed how multiple stresses constrain trait values and plasticity, and no study has included direct measurements of nutrient conservation traits, which are critical to plants growing in low‐resource environments.

•Methods:We evaluated how nutrient and water stresses affect growth and allocation, water potential and gas exchange, and nitrogen (N) allocation and use traits among a suite of six codominant species from the Intermountain West to determine trait values and plasticity. In the greenhouse, we grew our species under a full factorial combination of high and low N and water availability. We measured relative growth rate (RGR) and its components, total biomass, biomass allocation, midday water potential, photosynthetic rate, water‐use efficiency (WUE), green leaf N, senesced leaf N, total N pools, N productivity, and photosynthetic N use efficiency.

•Key results:Overall, soil water availability constrained plant responses to N availability and was the major driver of plant trait variation in our analysis. Drought decreased plant biomass and RGR, limited N conservation, and led to increased WUE. For most traits, native and nonnative species were similarly plastic.

•Conclusions:Our data suggest native and invasive biomass dominants may converge on functionally similar traits and demonstrate comparable ability to respond to changes in resource availability.
Fundamentals of Industrial Informatics and Communication Technologies
Authors: Ansari Abdul Quaiyum , Khan Mohammad Ayoub
Published: March 2012

The capabilities offered by Information and Communication Technologies (ICT) and business process have changed the paradigm of industrial practices. These ICTs have potential to create new type of industrial engineering. The chapter presents fundamental concepts and issues in industrial informatics along with the communication technologies. The authors also present discussion on design process and requirement of communications in industrial settings. The chapter also explores opportunities for research problems in the fields of wireless fieldbus systems and wireless industrial communications. In the discussion, the authors mention differences between theoretical and practical data rates. Therefore, opportunity involves the search for new protocol techniques to improve real-time capabilities in industrial settings.
Secure RFID-Enablement in Modern Companies
Authors: Schapranow Matthieu-P. , Müller Jürgen , Zeier Alexander , Plattner Hasso
Published: March 2012

Current RFID implementations suffer from security threats and privacy issues since the technology was not designed for secured data exchange. In emerging global RFID-aided supply chains, the need for open interfaces between supply chain partners exposes business secrets. A case study focusing on the development of detected counterfeits in the pharmaceutical industries in Europe and in the United States of America motivates the rising importance for RFID security. A formal model for describing RFID-aided supply chains is introduced to analyze flow of messages and data. Countermeasure tasks for all involved supply chain participants are defined to harden the integrity of the global supply chain. Motivated by concerns of exposing data via the air interface, two mutual authentication protocols are presented that aim to keep tag production costs low. Their applicability in context of the pharmaceutical industry is discussed.
Bridging From e-Government Practice to e-Government Research
Authors: Jun Kyu-Nahm , Weare Christopher
Published: March 2012

This chapter examines the state of the field of e-Government research to assess strategically how scholars may best target future research initiatives. While e-Government research is characterized by a great deal of interaction between practitioners and academic researchers, most research continues to either lack sufficient rigor to produce generalizable results or in search of rigor becomes too abstract to be directly useful to guide practice. Thus, despite the explosive growth in the field, there remain numerous opportunities to develop research projects that can both interest and aid practitioners and generate new theoretical and empirical knowledge. Through two reviews—one of the specialized e-Government literature and the other of general public administration and political science journals—this conceptual chapter identifies a number of research areas in which e-Government scholars and practitioners in the emerging economies may target their efforts.
Competence Development of E-Government
Authors: Grundén Kerstin
Published: March 2012

Effective implementation of e-Government demands the likelihood of appropriately incorporating all the multi-dimensional socio-technical factors in its design strategy. These socio-technical factors may involve, apart from the technological penetration and adoption, the different attitudes and competencies that may influence e-Government uptake. In this chapter, an interview study of a Web-based course for issues related to the implementation of e-Government is described and analysed. The design of the course was inspired by a study circle pedagogical approach. The respondents were especially positive to the group discussions of the studied course. Group-discussions and follow-up activities contributed to integrate learning outcomes into work practice. This study opines that there is a need to combine both development-oriented approaches with adaptive-oriented approaches in order to link different theoretical and practical aspects of the changed work-situation in the community of practice. There is also a need for pedagogical learning of producers and organisers of Web-based education in public organisations, in order to make them to be conscious about the importance of different pedagogical approaches, and the importance of making a thorough problem analysis before the design of the course.