bluuebunny/crossref_metadata_2025 huggingface dataset:
Predisposing factors to severe external root resorption associated to orthodontic treatment
Authors: Picanço Gracemia Vasconcelos , Freitas Karina Maria Salvatore de , Cançado Rodrigo Hermont , Valarelli Fabricio Pinelli , Picanço Paulo Roberto Barroso , Feijão Camila Pontes
Published: May 2013

OBJECTIVE: The aim of this study was to evaluate predisposing factors among patients who developed moderate or severe external root resorption (Malmgren's grades 3 and 4), on the maxillary incisors, during fixed orthodontic treatment in the permanent dentition. METHODS: Ninety-nine patients who underwent orthodontic treatment with fixed edgewise appliances were selected. Patients were divided into two groups: G1 - 50 patients with no root resorption or presenting only apical irregularities (Malmgren's grades 0 and 1) at the end of the treatment, with mean initial age of 16.79 years and mean treatment time of 3.21 years; G2 - 49 patients presenting moderate or severe root resorption (Malmgren's grades 3 and 4) at the end of treatment on the maxillary incisors, with mean initial age of 19.92 years and mean treatment time of 3.98 years. Periapical radiographs and lateral cephalograms were evaluated. Factors that could influence the occurrence of severe root resorption were also recorded. Statistical analysis included chi-square tests, Fisher's exact test and independent t tests. RESULTS: The results demonstrated significant difference between the groups for the variables: Extractions, initial degree of root resorption, root length and crown/root ratio at the beginning, and cortical thickness of the alveolar bone. CONCLUSION: It can be concluded that: Presence of root resorption before the beginning of treatment, extractions, reduced root length, decreased crown/root ratio and thin alveolar bone represent risk factors for severe root resorption in maxillary incisors during orthodontic treatment.
Evaluation of the friction force generated by monocristalyne and policristalyne ceramic brackets in sliding mechanics
Authors: Pimentel Roberta Ferreira , Oliveira Roberto Sotto Maior Fortes de , Chaves Maria das Graças Afonso Miranda , Elias Carlos Nelson , Gravina Marco Abdo
Published: May 2013

OBJECTIVE: To evaluate and compare "in vitro" the maximum friction force generated by three types of esthetic brackets, two types of polycrystalline conventional ceramic brackets (20/40 and InVu) and one type of sapphire monocrystalline bracket (Radiance) in dry and artificial saliva wet settings. Also, to evaluate the influence exerted by artificial saliva on the friction forces of those brackets. METHODS: Tests were performed in dry and artificial saliva wet setting (Oral Balance) by using an EMIC DL 10000 testing machine, simulating a 2 mm slide of 0.019 x 0.025-in rectangular stainless steel wires over the pre-angulated and pre-torqued (right superior canine, Roth prescription, slot 0.022 x 0.030-in) brackets (n = 18 for each bracket). In order to compare groups in dry and wet settings, the ANOVA was used. For comparisons related to the dry versus wet setting, the student t test was used for each group. RESULTS: The results showed that in the absence of saliva the Radiance monocrystalline brackets showed the highest friction coefficients, followed by the 20/40 and the InVu polycrystalline brackets. In tests with artificial saliva, the Radiance and the 20/40 brackets had statistically similar friction coefficients and both were greater than that presented by the InVu brackets. The artificial saliva did not change the maximum friction force of the Radiance brackets, but, for the others (20/40 and InVu), an increase of friction was observed in its presence. CONCLUSION: The InVu brackets showed, in the absence and in the presence of saliva, the lowest friction coefficient.
Mini-implants: mechanical resource for molars uprighting
Authors: Allgayer Susiane , Platcheck Deborah , Vargas Ivana Ardenghi , Loro Raphael Carlos Drumond
Published: May 2013

INTRODUCTION: The early orthodontic treatment allows correction of skeletal discrepancies by growth control, and the elimination of deleterious habits, which are risk factors for the development of malocclusions, favoring for the correction of tooth positioning later in a second treatment stage. During development of teeth and occlusion, the mandibular second molars commonly erupt in the oral cavity after all other teeth of the anterior region. In their eruptive process there may be a condition known as tooth impaction, which precludes its complete eruption and requires proper uprighting treatment. The temporary anchorage devices allow disimpaction and movement of these teeth directly to their final position, without the need of patient compliance or reaction movements in other parts of the arch. OBJECTIVE: This paper aims at describing a case report of the treatment of a patient with Angle Class II malocclusion, performed in two phases, in which mini-implants were used for uprighting the impacted mandibular second molars.
Surgical treatment of dental and skeletal Class III malocclusion
Authors: Brunharo Ione Helena Vieira Portella
Published: May 2013

Orthodontic preparation for surgical treatment of skeletal Class III malocclusion involves joint planning with an oral and maxillofacial surgeon to address the functional and esthetic needs of the patient. In order to allow surgical manipulation of the jaws in the preoperative phase, the need to achieve a negative overjet through incisor decompensation often leads the orthodontist to extract the upper first premolars. This report illustrates an orthodontic preparation case where due to specific factors inherent in the patient's psychological makeup retroclination of the upper incisors and proclination of the mandibular incisors was achieved without removing any teeth. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO) in partial fulfillment of the requirements for obtaining the BBO Diploma.
Relationship between temporomandibular disorders and orthodontic treatment: a literature review
Authors: Leite Ronaldo Antônio , Rodrigues Joacir Ferreira , Sakima Maurício Tatsuei , Sakima Tatsuko
Published: May 2013

OBJECTIVE: The objective of this study was to review the most recent studies from the last 15 years, in search of clinical studies that report the relationship between TMD and orthodontic treatment and/or malocclusion. Our intention was to determine whether orthodontic treatment would increase the incidence of signs and symptoms of TMD, and whether orthodontic treatment would be recommended for treating or preventing signs and symptoms of TMD. METHODS: Literature reviews, editorials, letters to the editor, experimental studies in animals and short communications were excluded from this review. Were included only prospective, longitudinal, case-control or retrospective studies with a large sample and significant statistical analysis. Studies that dealt with craniofacial deformities and syndromes or orthognathic surgery treatment were also excluded, as well as those that reported only the association between malocclusion and TMD. RESULTS: There were 20 articles relating orthodontics to TMD according to the inclusion criteria. The studies that associated signs and symptoms of TMD to orthodontic treatment showed discrepant results. Some have found positive effects of orthodontic treatment on signs and symptoms of TMD, however, none showed a statistically significant difference. CONCLUSIONS: All studies cited in this literature review reported that orthodontic treatment did not provide risk to the development of signs and symptoms of TMD, regardless of the technique used for treatment, the extraction or non-extraction of premolars and the type of malocclusion previously presented by the patient. Some studies with long-term follow-up concluded that orthodontic treatment would not be preventive or a treatment option for TMD.
Disintegration energy of sensitive clays
Authors: Thakur V. , Degago S. A.
Published: May 2013

The accurate assessment or prediction of landslides in sensitive clays is not a straightforward task due to the complexity associated with understanding such material during the sliding process. There have, however, been several attempts to assess flow slide potentials by looking at certain aspects of sensitive clays, one of which is studying the energy involved in the disintegration of sensitive clays from an intact to a remoulded state. This energy is referred to as disintegration energy (DE). Here, an analytical approach is proposed to evaluate the DE of sensitive clays based on an integrated study of strength and stiffness properties of sensitive clays in intact and remoulded states. The proposed approach is illustrated by studying the DE involved in Norwegian landslides. In addition, the proposed equation is shown to be in line with an equation used for Canadian sensitive clays. Furthermore, this article attempts to illustrate that the extent of flow slides is related to the DE involved in sensitive clays using five selected Norwegian landslides. The study shows that the amount of required DE can be used to estimate the extent of landslides in soft sensitive clays.
Quantifying effects of habitat heterogeneity and other clustering processes on spatial distributions of tree species
Authors: Shen Guochun , He Fangliang , Waagepetersen Rasmus , Sun I-Fang , Hao Zhanqing , Chen Zueng-Sang , Yu Mingjian
Published: May 2013

Spatially explicit consideration of species distribution can significantly add to our understanding of species coexistence. In this paper, we evaluated the relative importance of habitat heterogeneity and other clustering processes (e.g., dispersal limitation, collectively called the non‐habitat clustering process) in explaining the spatial distribution patterns of 341 tree species in three stem‐mapped 25–50 ha plots of tropical, subtropical, and temperate forests. Their relative importance was estimated by a method that can take one mechanism into account when estimating the effects of the other mechanism and vice versa. Our results demonstrated that habitat heterogeneity was less important in explaining the observed species patterns than other clustering processes in plots with flat topography but was more important in one of the three plots that had a complex topography. Meanwhile, both types of clustering mechanisms (habitat or non‐habitat) were pervasive among species at the 50‐ha scale across the studied plots. Our analyses also revealed considerable variation among species in the relative importance of the two types of mechanism within each plot and showed that this species‐level variation can be partially explained by differences in dispersal mode and growth form of species in a highly heterogeneous environment. Our findings provide new perspectives on the formation of species clustering. One important finding is that a significant species–habitat association does not necessarily mean that the habitat heterogeneity has a decisive influence on species distribution. The second insight is that the large species‐level variation in the relative importance of the two types of clustering mechanisms should not be ignored. Non‐habitat clustering processes can play an important role on species distribution.
Rarefaction and extrapolation with Hill numbers: a framework for sampling and estimation in species diversity studies
Authors: Chao Anne , Gotelli Nicholas J. , Hsieh T. C. , Sander Elizabeth L. , Ma K. H. , Colwell Robert K. , Ellison Aaron M.
Published: May 2013

Quantifying and assessing changes in biological diversity are central aspects of many ecological studies, yet accurate methods of estimating biological diversity from sampling data have been elusive. Hill numbers, or the effective number of species, are increasingly used to characterize the taxonomic, phylogenetic, or functional diversity of an assemblage. However, empirical estimates of Hill numbers, including species richness, tend to be an increasing function of sampling effort and, thus, tend to increase with sample completeness. Integrated curves based on sampling theory that smoothly link rarefaction (interpolation) and prediction (extrapolation) standardize samples on the basis of sample size or sample completeness and facilitate the comparison of biodiversity data. Here we extended previous rarefaction and extrapolation models for species richness (Hill number qD, where q = 0) to measures of taxon diversity incorporating relative abundance (i.e., for any Hill number qD, q > 0) and present a unified approach for both individual‐based (abundance) data and sample‐based (incidence) data. Using this unified sampling framework, we derive both theoretical formulas and analytic estimators for seamless rarefaction and extrapolation based on Hill numbers. Detailed examples are provided for the first three Hill numbers: q = 0 (species richness), q = 1 (the exponential of Shannon's entropy index), and q = 2 (the inverse of Simpson's concentration index). We developed a bootstrap method for constructing confidence intervals around Hill numbers, facilitating the comparison of multiple assemblages of both rarefied and extrapolated samples. The proposed estimators are accurate for both rarefaction and short‐range extrapolation. For long‐range extrapolation, the performance of the estimators depends on both the value of q and on the extrapolation range. We tested our methods on simulated data generated from species abundance models and on data from large species inventories. We also illustrate the formulas and estimators using empirical data sets from biodiversity surveys of temperate forest spiders and tropical ants.
The Initial Startup Wave Velocity in Isothermal Pipeline With Compressible Gelled Crude Oil
Authors: Guozhong Zhang , Wentao Xiao , Gang Liu , Hao Lan
Published: May 2013

The results of pipe-flow experiments show that the advancement velocity of pressure is considerably slower than the transient-pressure-wave velocity during the startup of pipeline with compressible gelled crude oil under constant flow rate. The startup wave velocity that dominates the advancement velocity of pressure in pipeline with compressible gelled crude oil was described and explained, and the essential difference between the startup wave velocity and the transient-pressure-wave velocity was also described in detail. The startup wave front marks the substantive commencement of breakdown of gel structure, and also indicates when the flow rate starts to become stable in the pipeline segments passed through during startup under constant flow rate, so it is a crucial factor affecting the calculation of startup pressure. In this paper, the efficient numerical formulas to compute the startup wave velocity were deduced on the basis of the analysis of 1D flow of viscoplastic media in elastic pipeline. The reliability of the formulae was verified by the well agreement between the calculated values and the results of pipeline startup experiments carried out with the N-Y gelled crude oil. These formulas facilitate scientific analysis for the safe and economical operation of pipeline transporting waxy crude oil. During the initial startup of pipeline with compressible gelled crude oil under constant flow rate, the startup wave velocity is considerably slower than the transient-pressure-wave velocity, decreases with the increase of the propagation distance and the gel strength of crude oil, and increases with the increase of startup flow rate (the volume elastic/plastic coefficient of gelled crude oil and the ratio of the wall thickness to the inside diameter of the pipeline). It is noticeable that the formulae deduced in this paper are not limited to the pipelines with gelled crude oil. They are also applicable to most kinds of pipelines transporting compressible viscoplastic fluid with strong structure.
Selection Criteria and New Technologies On The Artificial Lift Systems for Heavy-Oil And Extra-Heavy-Oil Wells In Colombia
Authors: Cuesta J. J. , Ortega J. D.
Published: May 2013

This paper is focused on analyzing the behavior of the oil industry in the last years in Colombia, where barrels of oil have increased considerably, both in secondary recovery processes of mature fields, as well as in field development and reservoir with heavy and extra heavy crude, is in this latter, where there is the greatest hope for achieving sustainable increase in reserves and production in the country, which is why it is very important the right selection process and criteria to choose the appropriate artificial lift system, according to the needs required by the conditions of each specific well.

Based on the experience already gained in different heavy oil and extra heavy oil fields in Colombia, will explain what are the best applications results obtained and what is the result of applying new technologies implemented in Colombia, for increased production.

The history of most operating companies shows that these operators focus on selecting different artificial lift systems without performing analysis with all team involved in other areas (such as areas of drilling, reservoir, subsurface, production and maintenance). The reservoir conditions, completion, and other characteristics of the field should be linked globally so that they can determine what is the best application of pumping system, to ensure optimal production of each well in specific.

The ultimate goal of this paper is to establish criteria that help oil companies to determine the proper selection process of the right artificial lift system for the operation and production of fields with heavy and extra heavy crude, and the end of this action, the result is to achieve the desire increase in oil in the field, and to increase oil production and reserves in Colombia.
Operational Cost Saving through Artificial Lift Optimization with Long Stroke Pumping Units in Fields of Cravo Viejo Block
Authors: Sarmiento Varela D. B. , Herrera J. F. , Caicedo M. R.
Published: May 2013

Based on mechanical pumping concept which includes long strokes and low pumping velocities as key factor to improve the lifting efficiency, a first experience in that area (Cravo Viejo Block) with Long Stroke Pumping Units was successfully developed, supplying proven technology and efficient designs and obtaining a high impact in wells with high pumping costs, failure rate and volume & depth wells.

Use of Long Stroke Pumping Systems as economic and efficient alternative to produce all oil wells where operational and energetic optimization is needed for artificial lift methods installed. For this specific case Hydraulic Lift was the traditional artificial lift system.

Since August 2010, nine artificial lift conversions were implemented achieving significant reductions in operation and maintenance costs compared to method previously installed in each well. Important decrease in operational and maintenance cost was achieved.

These savings are mainly represented by reducing of fuel consumption around 67% and 69% in lost production considering fewer corrective and preventive interventions. Besides, the short torque arm of these pumping units resulted in smaller gear reducers and more economical primer movers.

Additional benefits were got because of the improved geometry of Long Strokes Pumping Units like reduction of wearing effect on sucker rod strings and rod pumps components. Compressive efforts (buckling) and rod floating were reduced too because of lower pumping velocities handled.
An Uncommon Presentation of Tuberculosis with Cervical Pott’s Disease
Initially Suspected as Metastatic Lung Cancer
Authors: Buso Roberta , Rattazzi Marcello , Puato Massimo , Pauletto Paolo
Published: May 2013

Cervical Pott's disease is a rare clinical condition whose diagnosis is usually delayed. We report a case of lung
tuberculosis (TB) and cervical Pott’s disease mimicking a metastatic lung cancer. The patient presented with persistent
cervical pain. Radiologic examinations showed the presence of a lytic lesion of C3 vertebral body, associated with spinal
cord compression. A CT scan of the thorax showed a lung nodule highly suspicious for malignancy in the apical region of
right lung upper lobe. Neurosurgical decompression was performed. Unexpectedly, histological analysis showed the
presence of an inflammatory infiltrate suggestive for TB infection. The patient was immediately treated with
antituberculous drugs. Atypical forms of spinal TB, such as cervical TB, can be misdiagnosed as primary or metastatic
cancers and lead to delay of treatment initiation that could be fatal. Awareness of this uncommon TB presentation is
important to prevent morbidity and mortality associated with spinal cord injury and disease dissemination.
Morphological characteristics of the interspecies hybrid between Sorghum and Sudan grass under intensive nitrogen nutrition
Authors: Ikanovic Jela , Popovic Vera , Trkulja Vojislav , Zivanovic Ljubisa , Lakic Zeljko , Pavlovic Slobodanka
Published: May 2013

The object of this study was a two-year trial (2009 and 2010) regarding
variability of morphological characteristics of species belonging to Sorghum
genus, more specifically interspecies hybrid between sorghum and Sudan grass
Siloking as affected by different applications of nitrogen. The following
morphological characteristics were analysed: plant height, number of leaves,
leaf ratio, stem ratio, and number of shoots. Samples were taken from the
first cut when the effect of the applied nitrogen doses was the strongest.
The results showed that increasing nitrogen quantities significantly affected
the tested morphological characteristics, especially the intensity of
tillering (increased number of secondary stems), number of the formed leaves,
and ratio of leaf weight in the total above-ground biomass. The effect of
applied nitrogen depended on the weather conditions, i.e. distribution of
precipitation, so that plants reached maximum height when 105 kg N ha-1 was
applied in the dry year and 180 kg N ha-1 in the wet year.
Soluble free phenolic compound contents and antioxidant capacity of bread and durum wheat genotypes
Authors: Zilic Sladjana , Hadzi-Taskovic-Sukalovic Vesna , Dodig Dejan , Maksimovic Vuk , Kandic Vesna
Published: May 2013

The objective of this study was to determine phenolic compounds and the total
antioxidant capacity in the grain of ten bread (T. aestivum L.) and ten durum
(T. durum Desf.) wheat genotypes. Soluble free forms of total phenolics,
flavonoids, PVPP (polyvinylpolypyrrolidone) bound phenolics,
proanthocyanidins and phenolic acids were investigated. In addition, the
correlation coefficients between total antioxidant capacities and the
concentration of different soluble free phenolic compounds, as well as
between soluble free total phenolics and phenolic acids, flavonoids and PVPP
bound phenolics were determined. Significant differences in the content of
aceton/water extractable total phenolics, PVPP bound phenolics and phenolic
acids between and within two wheat species were found. On the average, durum
wheat samples had about 1.19-fold higher total phenolic compounds and about
1.5-fold higher PVPP bound phenolics than bread wheat samples. Three phenolic
acids, ferulic, caffeic and chlorogenic, were detected in wholemeal bread
wheat. Caffeic acid was not found in durum wheat samples whilst ferulic acid
was the most abundant. Proanthocyanidins in bread and durum wheat genotypes
were not detected. The antioxidant capacity measured as the DPPH radical
scavenging activity was similar in wholemeal of bread and durum wheat,
however, significant differences were observed among genotypes within
species.
Molecular characterization of barley (Hordeum vulgare L.) accessions of the Serbian GeneBank by SSR fingerprinting
Authors: Surlan-Momirovic Gordana , Krämer Ilona , Bratkovic Kamenko , Zoric Miroslav , Momirovic Una , Brankovic Gordana , Calic Irena , Kandic Vesna , Przulj Novo , Ordon Frank , Perovic Dragan
Published: May 2013

Molecular diversity of 145 barley (Hordeum vulgare subsp. vulgare L.)
accessions from the Serbian GenBank was assessed by single sequence repeats
(SSR) markers. A set of 15 SSRs, covering all chromosomes of the diploid
barley genome with 2-3 SSR markers per chromosome, with a range of 4-18
alleles per locus were used. In total, 15 loci and 119 alleles were detected,
with an average of 7.93 alleles per locus. The Polymorphic information
content value ranged from 0.220 to 0.782 with a mean value of 0.534.
Regarding the growth habit and row type groups, gene diversity was
comparatively higher for the spring (0.616) and six-rowed accessions (0.616)
than for the winter and two- rowed accessions (0.322 and 0.478,
respectively). Analysis of molecular variance showed that all sources of
variation were significant (P < 0.01), but the between-group component was
predominant (76.85%) for growth habit and 89.45% for row type. Unweighted
Pair Group Method with Arithmetic Mean (UPGMA) cluster analysis based on the
shared allele distance (DSA) matrix estimated on the SSR data assigned the
genotypes into two clusters - the first smaller consisting of the six 6-rowed
spring cultivars and the second comprising six subclusters. Genotype MBR1012
was separated from all other genotypes that constitute UPGMA tree. The
associations of genotypes belonging to different growth habit and row type
groups were assessed using Principal Coordinate Analysis revealing separation
of winter growth habit group from facultative one. The use of the STRUCTURE
clustering algorithm allowed the identification of 2 subpopulations of
genotypes.
Interaction of environment conditions and genotypes on expression of genetic background in micro-phenophases of strawberry mixed flower bud
Authors: Selamovska Ana , Kratovalieva Suzana , Nikolic Katerina
Published: May 2013

The aim of this research is differentiation or micro-phenophases of
reproductive organs on two junebearing strawberry (Fragaria x anannassa)
varieties senga sengana and pocahontas, depending on climate conditions,
rosettes ordering and cultivate manner (orchard mulched on black foil and
orchard on bare soil). The beginning of differentiation of flower buds is
genetic characteristic depending on climate conditions (insulations, day
length, higher midday and night air temperatures from 1.05 till the beginning
of differentiation, the sum of rainfalls from the beginning of May until the
end of July), order of rosettes and cultivate manner The sum of effective
temperatures over 10?C from 1st of May till the beginning of differentiation
has no influence on beginning of flower buds differentiation. First
morphological changes of the apical meristem were started in the first decade
of August that has coincided with the day length of 14 hours and day
insulations of 9.3 hours. Micro-phenophases were undergoing almost at the
same time in both varieties, only the beginning at pocahontas was 2-3 days
earlier. Primary rosettes differ 10-15 days earlier than the secondary
rosettes. Plants that grown on black foil had 7-10 days earlier flower bud
differentiation compared to those grown on bare soil.
The Accounting Entity, Relevance, and Faithful Representation: Linking Financial Statement Notes to the FASB and IASB Conceptual Frameworks
Authors: Ruhl Jack M. , Smith Ola M.
Published: May 2013

Although notes are an integral part of the financial statements, users lacking a technical accounting background often overlook them or consider them to be too difficult (Kieso et al. 2010). The authors observe that faculty generally devote little or no class time to the discussion or drafting of notes. Intermediate accounting textbooks relegate the presentation of notes to the end of the second intermediate accounting course. Nonetheless, notes are extremely important to financial statement users. In this case, students examine selected notes of the Consolidated Financial Statements of the Holy See (the financial entity associated with the Roman Catholic Papacy) for the year 2007. The Holy See's financial statement notes are ideal for discussion purposes, because students find “surprises.” Upon completion of the Discussion Questions, students have a new appreciation for financial statement notes, along with insights into how certain aspects of the FASB and IASB Conceptual Frameworks are linked to the notes. A case that attempted to include discussion of all the notes or the entire Conceptual Framework would become unwieldy. Therefore, in this case, we limit our focus to the accounting entity concept, relevance, and faithful representation. The case may be used with students enrolled in accounting courses from the principles level to the graduate level.
Circulating Estrone Levels Are Associated Prospectively With Diabetes Risk in Men of the Framingham Heart Study
Authors: Jasuja Guneet Kaur , Travison Thomas G. , Davda Maithili , Rose Adam J. , Zhang Anqi , Kushnir Mark M. , Rockwood Alan L. , Meikle Wayne , Coviello Andrea D. , D’Agostino Ralph , Vasan Ramachandran S. , Bhasin Shalender
Published: May 2013

OBJECTIVE

In postmenopausal women and preclinical murine models, estrogen administration reduces diabetes risk; however, the relationship of estradiol and estrone to diabetes in men is poorly understood. We determined the relationship between circulating estradiol and estrone levels and diabetes risk in community-dwelling men of the Framingham Heart Study (FHS).

RESEARCH DESIGN AND METHODS

Cross-sectional relationships of estradiol and estrone levels with diabetes were assessed at examination 7 (1998–2001) in FHS generation 2 men (n = 1,458); prospective associations between hormone levels at examination 7 and incident diabetes were assessed 6.8 years later at examination 8. Type 2 diabetes mellitus was defined as fasting glucose >125 mg/dL, medication use, or both. Estradiol, estrone, and testosterone levels were measured with liquid chromatography–tandem mass spectrometry, and free estradiol and estrone were calculated.

RESULTS

In cross-sectional models, men with elevated estrone and estradiol had 40% and 62% increased likelihoods of existing diabetes per cross-sectional doubling of estrone and estradiol levels, respectively. Free estrone (cross-sectional odds ratio 1.28 [95% CI 1.02–1.62], P = 0.04) was associated with impaired fasting glucose at examination 7. There was an increase in risk of existing diabetes with increasing quartiles of total and free estrone and estradiol and an increase in risk of incident diabetes with increasing quartiles of estrone levels. In multivariate longitudinal analyses, a twofold increase in total or free estrone levels at examination 7 was associated with 77 and 93% increases, respectively, in odds of incident diabetes at examination 8.

CONCLUSIONS

Although both estradiol and estrone exhibit cross-sectional associations with diabetes in men, in longitudinal analyses estrone is a more sensitive marker of diabetes risk than is estradiol.
Aggressive Blood Pressure Control Increases Coronary Heart Disease Risk Among Diabetic Patients
Authors: Zhao Wenhui , Katzmarzyk Peter T. , Horswell Ronald , Wang Yujie , Li Wei , Johnson Jolene , Heymsfield Steven B. , Cefalu William T. , Ryan Donna H. , Hu Gang
Published: May 2013

OBJECTIVE

Blood pressure control can reduce the risk of coronary heart disease (CHD) among diabetic patients; however, it is not known whether the lowest risk of CHD is among diabetic patients with the lowest blood pressure level.

RESEARCH DESIGN AND METHODS

We performed a prospective cohort study (2000–2009) on diabetic patients including 17,536 African Americans and 12,618 whites. Cox proportional hazards regression models were used to estimate the association of blood pressure with CHD risk.

RESULTS

During a mean follow-up of 6.0 years, 7,260 CHD incident cases were identified. The multivariable-adjusted hazard ratios of CHD associated with different levels of systolic/diastolic blood pressure at baseline (<110/65, 110–119/65–69, 120–129/70–80, and 130–139/80–90 mmHg [reference group]; 140–159/90–100; and ≥160/100 mmHg) were 1.73, 1.16, 1.04, 1.00, 1.06, and 1.11 (P trend <0.001), respectively, for African American diabetic patients, and 1.60, 1.27, 1.08, 1.00, 0.95, and 0.99 (P trend<0.001) for white diabetic patients, respectively. A U-shaped association of isolated systolic and diastolic blood pressure at baseline as well as blood pressure during follow-up with CHD risk was observed among both African American and white diabetic patients (all Ptrend <0.001). The U-shaped association was present in the younger age-group (30–49 years), and this U-shaped association changed to an inverse association in the older age-group (≥60 years).

CONCLUSIONS

Our study suggests that there is a U-shaped or inverse association between blood pressure and the risk of CHD, and aggressive blood pressure control (blood pressure <120/70 mmHg) is associated with an increased risk of CHD among both African American and white patients with diabetes.
Multi-proxy reconstruction of mire development in the Poręby Wojsławskie ecosystem (Sandomierz Basin, southeastern Poland)
Authors: Chodorowski Jacek , Plak Andrzej , Pidek Irena , Dobrowolski Radosław
Published: May 2013

Multi-proxy analysis (sedimentological, palaeobotanical, geochemical data and results of radiocarbon dating) of the biogenic sediments from a small mire ecosystem in the Sandomierz Basin (SE Poland) is presented. The ecosystem contains a full hydroseral sequence from minerotrophic to ombrotrophic wetland. It is one of the few sites in this region which is so thoroughly investigated in terms of the palaeoenvironmental record. Changes in the water supply of the mire area, and consequently the changes in the plant and sediment succession, were well correlated with the regional tendencies in precipitation and temperature during the Late Glacial/Holocene transition and in the Holocene. Human impact is very well recorded in pollen diagram from the Subboreal period.
Lexsyg — A new system for luminescence research
Authors: Richter Daniel , Richter Andreas , Dornich Kay
Published: May 2013

The newly developed lexsyg system by Freiberg Instruments is a versatile luminescence reader, suited for research on the luminescence of materials, fundamental research in luminescence dating, but also for routine mass measurements in retrospective dosimetry as well as in dating application. The 80 sample storage wheel is disconnected from the measurement chamber and therefore crosstalk of optical stimulation is absent and cross-irradiation is negligible from the α- and β-sources, which are providing very uniform irradiations, with the latter especially designed for radiofluores-cence (RF) measurement. Optical excitation sources and filter wheels to vary detection wavelengths can be programmed to change at almost any time within measurement sequences, including the auto-mated change of an optional wheel holding up to four different detectors. Thermoluminescence meas-urements and preheating are possible with a versatile heater, which can be programmed for linear or non-linear heating or cooling, as well as holding a temperature constant. Rates as well as durations can be varied, together with individual ramping, staging and cooling for an almost unlimited number of steps. Violet- and IR-lasers, green and blue LED-arrays can be operated in continuous (CW) or modulated mode (linear/non-linear), and optionally for pulsed as well as time resolved luminescence detection. Six arrays of power LEDs allow the simulation of different bleaching regimes (‘solar simu-lator’), while luminescence detection can be achieved by a variety of photomultiplier tubes and by CCD cameras for spatially resolved measurements and luminescence spectra.
Uncertainty of Maintenance Strategies for Bridge Sustainability Assessment
Authors: Zinke Tim , Ummenhofer Thomas
Published: May 2013

To perform a sustainability assessment for bridges forecasts of the renewal cycles have to be made. The paper concentrates on impacts during the life cycle of highway bridges with a span of approximately 50 m. The spatial boundaries are set to the country of Germany. Considering these boundary conditions, approaches for the renewal cycles of all bridge components based on statistical analysis of the German road infrastructure information system (SIB-Bauwerke) are presented. Aspects like data quality and restrictions of the database are discussed. These input data are used to derive three possible maintenance strategies: preventive maintenance, condition-based maintenance and permitted deterioration. These strategies are suitable to include scenario uncertainties into the sustainability assessment of bridges with a life span of at least 100 years.
Integrated Asset Management Tool for Highway Infrastructure
Authors: Veit-Egerer Robert , Widmann Monika , Furtner Peter , Lima Rui
Published: May 2013

To enable proper and long-term maintenance planning for a huge and heterogeneous set of engineering structures (bridges, culverts, noise barriers, gantries) the authors developed an integrated life cycle management tool that offers tailored solutions with regard to the given location, involved materials, fabricates and the underlying design code at the time of construction. The core of this tool is formed by a probabilistic ageing model and a comprehensive cost model. Each structural member is represented by a generic ageing function, which is derived from the major sources of information reflecting impact on structural ageing (visual inspection/ numerical simulation/ structural monitoring and freight traffic progression). Furthermore the model incorporates VCE’s 50 years of experience in the field of bridge inspections and structural health monitoring. Due to defined treatment-trigger-criteria a huge set of maintenance strategies is generated leading to an extensive optimization exercise. The final project output is composed by tailored maintenance plans for every structure.
Assessment and maintenance plan for 36 structures near Coentunnel - Amsterdam
Authors: Dekoning Nico , van den Bossche Bernd
Published: May 2013

The ring of Amsterdam is ongoing for an enlargement. One of the bottlenecks is the passing under the North Sea canal in Amsterdam. This passing is named the Coentunnel, named by a famous Dutch officer of the Dutch East Indie Company.

Building a new tunnel below the canal now doubles this tunnel.

At both sides of the Coentunnel traffic exchangers are build, 36 of this structures needs to be maintained by the Coentunnel construction company.

Before a maintenance plan could be made, an in depth assessment of the constructions was done. A number of bridges and tunnels were grouped; if they were build at the same time, with the same method, the same design, the same concrete.

This resulted in 9 groups of constructions. Of each of these groups one construction was assessed : the abutment, columns, decks and if possible the foundations were investigated.

Al these elements were assessed to Chloride induced corrosion, Carbonation induced corrosion, Alkali silica reaction, Delayed ettringite formation.

The Chloride induced corrosion was done by measuring the chloride distribution on minimal 3 cores, and concrete cover, resulting is the calculation of the initial chloride content, diffusion coefficient and surface chloride content. With these parameters the remaining lifetime is calculated. If the functional lifetime did not meet the specified lifetime, addiditonal maintenance measures were engineered.

At the end a series of maintenance plans were edited in order to guarantee the functionality of the structure during the maintenance period and until the end of lifetime period.

Special to these assessments was that the procedure was conforming ‘systems engineering’ like mentioned in ISO 15288.
Shear Capacity of Concrete Beams under Sustained Loading
Authors: Sarkhosh Reze , Walraven Joost , den Uijl Joop , Braam René
Published: May 2013

Long-term tests on large-scale concrete beams without shear reinforcement, which are tested for more than two years under sustained loading close to the ultimate shear capacity (load ratio ranging from 87% to 95%) under climate controlled condition, show that sustained loading has no significant effect on the shear capacity. Although many flexural and shear cracks develop, the beams carry the load for a long time. The tests show that crack formation takes place only within some days after the load application, but after a week the cracks stabilize and become dormant.
Structural Verification of Older Prestressed Concrete Road Bridges in Germany
Authors: Dunkelberg Daniel , Zilch Konrad
Published: May 2013

The paper specifies the scope and briefly summarizes the content of the German Provisions for Structural Assessment of Older Road Bridges. The general assessment procedure is described and aspects like modified partial factors and traffic loads to be considered are addressed. A special focus is put on the modified approach for the verification of shear load carrying capacity of prestressed concrete bridges.
Experimental studies on the shear capacity of Prestressed Concrete Continuous Beams
Authors: Herbrand Martin , Hegger Josef
Published: May 2013

A large number of existing bridges of the German Federal Highways are built as prestressed concrete continuous beams. Because of rising traffic loads, the calculated shear capacity of some bridges is insufficient according to current codes. However, the calculated shear capacity might be underestimated by the design codes and the actual shear capacity may be increased, e.g. by using additional external tendons. This paper presents a research project that is carried out at the Institute of Structural Concrete at RWTH Aachen University. Six tests on three continuous beams with parabolic and additional external tendons were performed. The aim was to investigate whether the shear capacity is accurately predicted by the current bridge design code or if the shear capacity can be calculated more precisely by alternative approaches, especially regarding the influence of additional external tendons.
Shear Capacity of Bridge Deck Cantilever Slabs without Shear Reinforcement
Authors: Reissen Karin , Hegger Josef
Published: May 2013

Rising traffic loads have increased the requirements for the load-carrying capacity of bridges significantly. Furthermore, German design code rules have changed during the last decades reducing the calculated shear capacities of reinforced concrete members without shear reinforcement. Therefore, the calculated shear capacity of many existing bridge deck slabs without shear reinforcement is not sufficient according to the present design rules. These deficits are demonstrated by means of a design example. Since shear failure and excessive crack formation have not been observed in existing bridges to date, the bridges are evidently able to carry the increased traffic loads. The shear capacity of reinforced concrete slabs without shear reinforcement has therefore been investigated at the Institute of Structural Concrete at RWTH Aachen University and a modified approach for the effective width for shear of cantilever slabs is proposed.
Shear Resistance Mechanism of RC Column Retrofitted by using PC Bars
Authors: Nakada Kozo , Morishita Yoichi , Uehara Sanae , Yamakawa Tetsuo
Published: May 2013

It is a known fact that the compressive strength and ductility of concrete can be considerably improved by lateral confinement. In this study, a ductility-type seismic retrofitting technique of RC columns by utilizing high-strength steel bars (PC bars) prestressing was applied, which is arranged on the four faces of the RC columns as external hoops. Hence, active confinement due to the tensile forces in the PC bars as well as passive confinement and transverse reinforcement can be expected. Recent axial compression tests showed that the active and passive confinement using PC bar prestressing can considerably improve the stress–strain characteristics of confined concrete. In this paper, the shear resistance mechanism and shear strength of RC columns retrofitted using PC bar prestressing was experimentally investigated under constant axial force and cyclic lateral forces.
Shear Assessment of Reinforced Concrete Slab Bridges
Authors: Lantsoght Eva O. L. , van der Veen Cor , Walraven Joost C. , de Boer Ane
Published: May 2013

The capacity of reinforced concrete solid slab bridges in shear is assessed by comparing the design beam shear resistance to the design value of the applied shear force due to the permanent actions and live loads. Results from experiments on half-scale continuous slab bridges are used to develop a set of recommendations for the assessment of slab bridges in shear. A method is proposed allowing to take the transverse force redistribution in slabs under concentrated loads into account, as well as a horizontal load spreading method for the concentrated loads. For selected cases of existing straight solid slab bridges, a comparison is made between the results based on the shear capacity according to the Dutch Code NEN 6720 and from the combination of the Eurocode (EN 1992-1- 1:2005) with the recommendations, showing an improved agreement.
Effectiveness of GPR on Structural Assessment: Hints for the Potential User
Authors: Trezos Konstantinos G. , Palieraki Vassiliki , Sfikas Ioannis P.
Published: May 2013

In the current study, the results from various in-situ calibrations in several existing concrete structures are being presented and discussed, leading to useful conclusions and comments about the correct application and the effectiveness of Ground Penetrating Radar (GPR) technique on structural integrity assessment. Specifically, the effect of two different antenna frequencies on scan results is being examined. Two types of scan modes, distance and time, have been applied and are being evaluated. Other parameters, like antenna contact to the concrete surface, scan velocity, antenna resolution and scan repeatability, are also being investigated. The application of grid versus linear scan patterns is being discussed. Useful observations and hints are reported for the potential users of GPR. It has been found that high quality results can be obtained by using a suitable antenna frequency, the use of carefully selected data acquisition settings and a steady scan application, in terms of the antenna to surface contact and scan velocity. Additionally, the high level of repeatability allows the monitoring of infrastructure in recursive intervals, which may prevent the expansion of local intrinsic defects.
Bond Characteristics between Fiber-Reinforced Polymer Composite Laminate and Prestressed Concrete
Authors: Ali M. Shafqat , Mirza M. Saeed , Lessard Larry
Published: May 2013

Fiber-reinforced polymer composite shell or membrane placed externally around the lower bulb of a pre-stressed concrete girder can help eliminate, or significantly reduce chloride ingress, and also help to enhance its service life. The bond at the FRP composite shell and prestressed concrete interface was studied experimentally to evaluate the flexural and shear behaviour of FRP composite shell-reinforced prestressed concrete bridge girders. Simple tension specimens, consisting of prestressed concrete prisms with externally-bonded FRP composite laminates, using pre-glued aggregates to the FRP composite laminates, with five levels of prestressing (0, 25, 50, 75, and 100%), were prepared and tested. These specially designed hybrid FRP composite laminates demonstrated good results for bond characteristics at the FRP composite laminate-concrete interface, and improved the strength and stiffness of the prisms. The tensile strength at initial cracking in the simple FRP-reinforced specimen was almost twice that of the control specimens.
Research on Assessment and reinforcement of bridge structures
Authors: Bujnak Jan , Koteš Peter , Kotula Patrik
Published: May 2013

The experiment results given in the paper show that effective strengthening of bridge structural elements can be achieved by using advanced fibre composite system. The theoretical study indicates that the current design methods are quite conservative. Based on finite element modelling new approaches are investigated experimentally and theoretically.