European Formula Research Articles

Age at onset prediction in spinocerebellar ataxia type 3 changes according to population of origin.

In spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD), the length of CAG repeat expansions in ATXN3 shows an inverse correlation with age at onset (AO). Recently, a formula for predicting AO based on CAG expansion was developed for European carriers. We tested this formula in SCA3/MJD carriers from distinct origins and developed population-specific models to predict AO. This was a parametric survival modelling study. The European formula (EF) was tested in 739 independent SCA3/MJD carriers from South Brazil, Taiwan and the Portuguese Azorean islands, and it largely underestimated AO in South Brazilian and Taiwanese test cohorts. This finding challenged the universal use of the EF, leading us to develop and validate population-specific models for AO prediction. Using validation cohorts, we showed that Brazilian and Taiwanese formulas largely outperformed the EF in a population-specific manner. Inversely, the EF was more accurate at predicting AO among Portuguese Azorean patients. Hence, specific prediction models were required for each SCA3/MJD ethnic group. Our data strongly support the existence of as yet unknown factors that modulate AO in SCA3/MJD in a population-dependent manner, independent of CAG expansion length. The generated models are made available to the scientific community as they can be useful for future studies on SCA3/MJD carriers from distinct geographical origins.

Age estimation: Cameriere's open apices methodology accuracy on a southeast Brazilian sample

Age estimation plays an important role in clinical and forensic dentistry. Cameriere's 2007 open apices method for age estimation was applied in a sample of 612 digital panoramic orthopantomographs from Brazilian subadult individuals of known age and sex. The sample was composed of 290 males and 322 females individuals aged between four and 16 years of age from São Paulo metropolitan area who had undertaken radiographs for clinical purposes. Participant's ethnicity data was not available. An open code computer-aided drafting software (ImageJ) was used to measure the variables according to the author's published guidelines. Subjects' age was firstly estimated under the application of the European formula (2007) showing under-estimation (−1.24yr). On the other hand, the linear regression analysis modeled for this specific population was able to explain 91.2% of the chronological age variation with a standard error of 0.91yr. Residual analyses confirmed independent errors and a normal distribution. In conclusion, the present results support Cameriere's method for age estimation in Brazilian subadults to be a reliable method, although correlations may vary between specific groups and, hence, specific formulae may be useful for an accurate prediction.

Comparison of radiological dental age estimation by means of the method by Cameriere and the modified European formula

Introduction. Dental age apart from skeletal age is an important factor in the estimation of biological age of patients. Its evaluation is crucial in making decisions concerning diagnostic algorithms and treatment options in such fields of medicine as paedodontics, conservative dentistry, orthodontics, paediatrics or endocrinology as well as for forensic purposes. There are various methods of radiological dental age estimation and their validity is related to the studied population. Aim. The aim of the paper is to estimate dental age by means of two radiological methods based on panoramic radiographs, i.e. the original method by Cameriere and the modified European formula. Material and methods. The material consisted of 2148 digital radiographs taken in patients of both genders, aged from 5 to 15 years, with visible germs of all permanent teeth, apart from third molars. Two methods by Cameriere were applied – the original one and the European formula. Statistical analysis was performed. Results. Dental age obtained by means of the two Cameriere’s methods was significantly different from chronological age (Wilcoxon’s test, p < 0.001). However, in the case of the original method the mean dental age was lower than the chronological one, while the European formula led to the overestimation of dental age. Conclusions. The European formula is more suitable for the evaluation of the Polish population than the original method by Cameriere.

Dental maturity assessment in Serbian population: A comparison of Cameriere’s European formula and Willems’ method

AimsTo test the applicability of European formula for dental maturity estimation in non-adults on Serbian sample and compare its accuracy with Willems’ age estimation method. Materials and methodsPanoramic radiographs of 423 children (192 boys and 231 girls) aged between 5 to 15 were evaluated. Willems’ method and European formula were applied to estimate dental age. Intra-class correlation (ICC) coefficients between estimated age and chronological age for each method and sex were reported separately. Furthermore, the percentage of individuals with estimated age within error range of ±0.5 year was calculated. ResultsTotal sample was divided into three groups (<7 years, 7–13 years, ≥13 years). In individuals younger than 7 years, the highest ICC coefficients were achieved with European formula (0.609 in girls and 0.487 in boys). Willems’ method showed better ICC coefficients in individuals older than 13 years (0.378 in girls and 0.600 in boys). In individuals between 7 and 13 years, ICC coefficients were between 0.800 and 0.900 with both methods European formula estimated the age in 47.6% of girls and 42.5% of boys within error range of ±0.5 year. Willems’ method reported similar results (45.4% in girls and 40.4% in boys). ConclusionsThe Willems’ method is more appropriate for individuals older than 13 years. European formula gives better results for individuals younger than 7 years. In individuals between 7 and 13 years there is no significant difference between European formula and Willems’ method, yet, European formula was found to be slightly more accurate.

Cameriere’s European formula for age estimation: A study on the children in Bosnia and Herzegovina

Introduction: A method for age estimation, based on measurements of projections of open apices and heights of developing permanent teeth on orthopantomograms (OPTs), was presented by Cameriere in 2006 and adopted European formula was presented in 2007.Aim: This cross-sectional study tested the accuracy of Cameriere’s European formula on a sample from the City of Sarajevo, Bosnia and Herzegovina.Materials and methods: A final sample of 560 OPTs of 305 girls and 255 boys aged 8 to 14 years was obtained. The sample was collected at the Department of Orthodontics, School of Dental Medicine at the University of Sarajevo (SFUNSA). Dental age was compared to chronological age and mean absolute error (MAE) was calculated. Intra-rater and inter-rater agreement of the evaluated variables were calculated.Results: The dental age was underestimated when compared to chronological age, precisely, mean underestimation was -0.14 years in girls and -0.17 years in boys. The values of MAE were 0.62 years in girls and 0.56 years in boys. The greatest error was found for the 14-year old group; DA was -1.04 years and -0.70 years in girls and boys respectively.Conclusion: Our results showed that Cameriere’s European formula might be a useful tool for age estimation in children from Bosnia and Herzegovina under the age of 14 years.

Age estimation in northern Chinese children by measurement of open apices in tooth roots.

The aim of this study was to assess the accuracy of Cameriere's methods on dental age estimation in the northern Chinese population. A sample of orthopantomographs of 785 healthy children (397 girls and 388 boys) aged between 5 and 15 years was collected. The seven left permanent mandibular teeth were evaluated with Cameriere's method. The sample was split into a training set to develop a Chinese-specific prediction formula and a test set to validate this novel developed formula. Following the training dataset study, the variables gender (g), x 3 (canine teeth), x 4 (first premolar), x 7 (second molar), N 0, and the first-order interaction between s and N 0 contributed significantly to the fit, yielding the following linear regression formula: Age = 10.202 + 0.826 g - 4.068x 3 - 1.536x 4 - 1.959x 7 + 0.536 N 0 - 0.219 s [Symbol: see text] N 0, where g is a variable, 1 for boys and 0 for girls. The equation explained 91.2 % (R (2) = 0.912) of the total deviance. By analyzing the test dataset, the accuracy of the European formula and Chinese formula was determined by the difference between the estimated dental age (DA) and chronological age (CA). The European formula verified on the collected Chinese children underestimated chronological age with a mean difference of around -0.23 year, while the Chinese formula underestimated the chronological age with a mean difference of -0.04 year. Significant differences in mean differences in years (DA - CA) and absolute difference (AD) between the Chinese-specific prediction formula and Cameriere's European formula were observed. In conclusion, a Chinese-specific prediction formula based on a large Chinese reference sample could ameliorate the age prediction accuracy in the age group of children.

Analysis of Imposed Bridge Load Stresses for Development of a European Bridge Formula

This paper evaluates the characteristics of international bridge formulas developed and implemented by different countries and analyzes the imposed bridge load effects resulting from trucks complying with international bridge formula–allowable loads and truck size and weight regulations in Europe. This evaluation was done to identify issues that may need to be considered in the development of a European bridge formula for the regulation of truck size and weight limits associated with international travel between European Union member states. Differences in national weight limits in European Union countries and the increasing demand for larger and heavier vehicles bring about the need to ensure the structural integrity and service life of bridges. Bridge formulas provide a method for regulating truck weights while ensuring the sustainability of infrastructure by allowing vehicle configurations that have an acceptable load effect on structures. This method allows for long-term truck size and weight evolutions for productivity gains while preserving the existing stock of bridges. The level of efficiency of a bridge formula varies depending on the design criteria used in the development of the formula, the compatibility of the jurisdiction's infrastructure and truck fleet characteristics, and the method of implementation as part of the regulation and by operators in the trucking industry. This research can help guide the development of a European bridge formula and contributes new knowledge for countries that currently apply a bridge formula to regulate truck weights.

Non-monotonic pricing kernel and an extended class of mixture of distributions for option pricing

We derive closed form European option pricing formulae under the general equilibrium framework for underlying assets that have an \(N\)-mixture of transformed normal distributions. The component distributions need not belong to the same class but must all be transformed normal. An important implication of our results is that the mixture of distributions is consistent with a “what appears to be abnormal” non-monotonic (asset specific) pricing kernel for the S&P 500 and that the representative agent has a “logical” monotonic decreasing marginal utility. We show that a mixture of two lognormal distributions is sufficient to produce this result and also implied volatility smiles of a wide variety of shapes.

ANÁLISIS DE LA PERCEPCIÓN DE LOS RESIDENTES SOBRE EL IMPACTO CULTURAL Y DEPORTIVO DE UN GRAN PREMIO DE FÓRMULA 1

O objetivo do estudo é analisar a percepção dos residentes em relação ao impacto cultural e desportivo do Grande Prêmio da Europa de Fórmula 1. Realizou-se uma análise cluster, combinando métodos hierárquicos e não hierárquicos, que permitiu encontrar três grupos com percepções diferentes frente a este evento esportivo: Desfavoráveis, Desfavoráveis Moderados e Favoráveis Moderados. Os residentes consideram em sua maioria que este evento não tem um impacto considerável no nível cultural e esportivo. Também se encontraram diferenças entre os três grupos de residentes em função do interesse pela Fórmula 1, o respaldo ao evento, a assistência e o grau de identificação.

Relationship between anthropometric parameters, physiological responses, routes and competition results in formula windsurfing

Formula windsurfing is faster than the Olympic version, due to anumber of unique differences. This study was designed to identify the importance of anthropometric and cardiac factors on the final result of the European Formula Windsurf Championships (2007). We selected 45 competitors (30 amateurs and 15 professionals) of 30±9.77 years of age, a height of 182.6±0.06 cm, a weight of 81.67±7.35 kg and a BMIof 24.7±2.1 kg. They were divided into three groups (PG: 15; TG: 45and GPSG: 12). We followed the recommendations of Carter and Marfell-Jones for the anthropometric measurements. The route, speed, distance and heart rate were recorded using an FRWD W600 GPS (Global Positioning System) unit. The anthropometric measurements indicate a professional profile with 2.3±0.4 endomorphy 5±0.8 mesomorphy and 2.4±0.6 ectomorphy. Arm span and fat mass show a significant (p≤0.02) and very significant (p≤0.005) correlation with the final classification. The average speed was 11.84±2.38 km·h–1, the heart rate varied from 128 to 180 b·min–1 and the average was 127.62±13.73 b·min–1. The distances covered (12784.77±5522.19 m) and the times used for the races (2049.3±989.68 s) were very variable. This will assist not only in initial selection for the sport, but also in the design of training programmes which further develop that morphology, where possible, in the pursuit of improved performance.

A Collation of Recently Published Western European Formulae for Age Estimation of Subadult Skeletal Remains: Recommendations for Forensic Anthropology and Osteoarchaeology

The aim of this study is to provide an effective and quick reference guide based on the most useful European formulae recently published for subadult age estimation. All of these formulae derive from studies on postnatal growth of the scapula, innominate, femur, and tibia, based on modern skeletal data (173 ♂, 173 ♀) from five documented collections from Spain, Portugal, and Britain. The formulae were calculated from Inverse Regression. For this reason, these formulae are especially useful for modern samples from Western Europe and in particular on 20th century human remains from the Iberian Peninsula. Eleven formulae were selected as the most useful because they can be applied to individuals from within a wide age range and in individuals of unknown sex. Due to their high reliability and because they derive from documented European skeletal samples, we recommend these formulae be used on individuals of Caucasoid ancestry from Western Europe.

Validation of Advanced Paediatric Life Support Formulas for Weight Calculation in a Multiethnic Population

Introduction. The aims of this study were to validate the new formulas for weight calculation introduced by the advanced life support group (alsg) of the United Kingdom in 2011 and compare their performance to the formula currently used by the European Resuscitation Council (ERC) and other formulas and to check whether performance of formulas for weight calculation is affected by ethnic group and gender. Methods. Prospective audit of weight versus calculated weight comparing alsg formula with ERC, Luscombe, Argall, and Best Guess formulas analysed for gender, age, and ethnic groups. Results. Prospectively 599 children were included: 157 Asian, 268 Caucasian, and 174 children from other origin. In infants there was no difference between actual weight and alsg formula calculated weight. There was a progressively increased underestimation of weight year by year from 1 to 10 years of age using the ERC formula. In the 6–10 year age group the ERC formula underestimated the weight by a mean of 6.5 kg (21.8%, P < 0.001) with the alsg and Luscombe formulas performing best. In 11-12 year old children the alsg formula estimated well. Conclusion. In one- to ten-year-old children, the Luscombe formula provided a better weight estimate than alsg and ERC formulas in a multiethnic population.

Stature and body mass estimation from skeletal remains in the European Holocene

Techniques that are currently available for estimating stature and body mass from European skeletal remains are all subject to various limitations. Here, we develop new prediction equations based on large skeletal samples representing much of the continent and temporal periods ranging from the Mesolithic to the 20th century. Anatomical reconstruction of stature is carried out for 501 individuals, and body mass is calculated from estimated stature and biiliac breadth in 1,145 individuals. These data are used to derive stature estimation formulae based on long bone lengths and body mass estimation formulae based on femoral head breadth. Prediction accuracy is superior to that of previously available methods. No systematic geographic or temporal variation in prediction errors is apparent, except in tibial estimation of stature, where northern and southern European formulae are necessary because of the presence of relatively longer tibiae in southern samples. Thus, these equations should bebroadly applicable to European Holocene skeletal samples.

Age estimation in children by measurement of open apices in tooth roots: Study of a Mexican sample

The aim of this cross-sectional study was to test the accuracy of Cameriere's European formula for age assessment in a large sample of Mexican children. The accuracy of dental age estimation was defined as how closely real age, measured as the difference between chronological age (CA) and dental age (DA), could be predicted. Digitalized orthopantomographs of 502 Mexican children (254 girls and 248 boys), aged between 5 and 15years, were analyzed. The seven left permanent mandibular teeth were evaluated using Cameriere's method. Intra- and inter-observer variability for this technique was tested on a small random sample. Dental age was estimated for each individual and compared with known chronological age. Accuracy was measured as the difference between known chronological age and dental age and tested for significance with the mean prediction error (ME). The standard deviation and 95% confidence interval of the mean difference were also calculated. ME was 0.63years for girls and 0.52years for boys. ME was found to be slightly overestimated by 0.10years for girls, but was correctly estimated for boys with an accuracy of 0.00. In conclusion, this method is very useful and may be recommended for practical application both in clinical dentistry and forensic procedures on the Mexican population.

Investigating the injury risk in frontal impacts of Formula Student cars: a computer-aided engineering analysis

This paper presents a parametric study of the injury risk in collisions of race cars designed for the European Formula Student competition. The study is motivated by the fact that only a limited assessment of driver safety is required for this competition. The approach was to model a Formula Student car in a mathematical dynamic model environment. A parametric study was then carried out to investigate the sensitivity of injury to various system variables. These were the crash pulse, the occupant stature, and the occupant posture. These system variables, under close examination, can be changed to alter the occupant kinematics or, in other words, they change the injury risk. The results of the analysis showed that the risk of injury in a frontal impact was dependent on the system variables. The risk of an abbreviated injury scale (AIS)2+ injury was 22.3 per cent in the baseline constant- g test, increasing to 35.2 per cent in the worst case. For AIS3+ the values were 5.1 per cent and 11 per cent, respectively. The study also showed that the occupant restraint conditions in a Formula Student car had a significant influence on the distribution of the injury risk between the body regions. The variation in the injury risk highlighted by this study, both in absolute terms and in the distribution between the body regions, showed that there are limitations to the use of vehicle kinematics in their current guise as a predictive tool for the injury risk. The results of this study represent a significant step in the understanding of the injury risk in a Formula Student frontal impact.

KNN Algorithm Based on Weighted Entropy of Attribute Value

The traditional KNN algorithm usually adopts European distance formula to measure the distance between two samples. Since each attribute functions differently in the actual sample data collection, the accuracy of the classification will be reduced consequently, this article proposes one method to measure the attribute value and entropy weight, namely KNN algorithm based on weighted entropy of attribute value. The experiment indicated that, compared with the traditional KNN algorithm, the algorithm proposed in this article can not only guarantee the efficiency of classification but also enhance the accuracy of classification.

Accuracy of Cameriere, Haavikko, and Willems radiographic methods on age estimation on Bosnian–Herzegovian children age groups 6–13

The aim of this cross-sectional study was to compare the accuracy of the Cameriere European formula (Cameriere), adopted Haavikko method from 1974 (Haavikko), and revisited Demirjian method by Willems (Willems) for age estimation on orthopantomograms (OPGs) of Bosnian-Herzegovian (BH) children age groups 6-13years. The accuracy was determined as difference between estimated dental age (DA) and chronological age (CA) and the absolute accuracy (absolute difference) was assessed by analyzing OPGs of 591 girls and 498 boys. The Cameriere method overestimated the mean age by 0.09year for girls and underestimated by -0.02year for boys. The Haavikko method underestimated the mean age by -0.29year for girls and -0.09year for boys. The Willems method overestimated the mean age by 0.24year in girls and by 0.42year in boys. The absolute accuracies were 0.53year for girls and 0.55year for boys for Cameriere method; for Haavikko method, 0.59year for girls and 0.62year for boys; and for Willems method 0.69year for girls and 0.67year for boys. In conclusion, Cameriere method is the most accurate for estimating the age of BH children age groups 6-13years using OPGs, following adopted Haavikko method and Willems method.

Age estimation in children by measurement of open apices in teeth: an Indian formula

The aim of this paper is twofold: first, to evaluate an Indian sample by Cameriere's European formula; and second, if this formula turns out to be unsuitable, to study a specific formula for Indian children. Orthopantomographs taken from 480 Indian children (227 girls and 253 boys) aged between 3 and 15 years were analyzed. Following the pilot study, subjects' age was modeled as a function of gender (g), region of country (C), and morphological variables (predictors: x (5), the distance between the inner sides of the open apex of the second premolar divided by the tooth length; s=x1+x2+x3+x4+x5+x6+x7, sum of normalized open apices; N (0,) the number of teeth with root development complete. Results showed that all these variables except gender and second premolar contributed significantly to the fit so that all were included in the regression model, yielding the following linear regression formula: Age=9.402-0.879C+0.663 N0-0.711s-0.106s N0 where C is a dummy variable equal to 0 for the center or north of India and 1 for the south. The above equation, with the variables considered, explained 89.7% (R (2) = 0.897) of total deviance. The median of the residuals (observed age minus predicted age) was -0.063 years, with an interquartile range of 1.10 years.

Age estimation in children by measurement of open apices in teeth: a European formula

The aim of the present paper was to improve and expand research with a larger number of children from various European countries and to provide a common formula useful for all these countries. Orthopantomographs taken from 2,652 European Caucasian children (1,382 boys, 1,270 girls) aged between 4 and 16 years were analyzed. The children came from Croatia, Germany, Kosovo, Italy, Slovenia, Spain, and the UK. Following the pilot study, subjects' age was modeled as a function of gender (g), morphological variables (predictors) x 5(second premolar), s (sum of normalized open apices) N 0, and the first-order interaction between s and N 0. The results showed that all these variables contributed significantly to the fit, so that all were included in the regression model, yielding the following linear regression formula: Age = 8.387 + 0.282 g - 1.692 x 5 + 0.835 N 0 - 0.116 s - 0.139 s x N 0, where g is a variable, 1 for males and 0 for females. The equation explained 86.1% (R2 = 0.861) of total deviance. The median of the residuals (=observed age minus predicted age) was -0.114 years, with (RefB.2) interquartile range = 1.22 years.

A Semi‐Explicit Approach to Canary Swaptions in HJM One‐Factor Model

Leveraging the explicit formula for European swaptions and coupon‐bond options in the HJM one‐factor model, a semi‐explicit formula for 2‐Bermudan options (also called Canary options) is developed. The European swaption formula is extended to future times. So equipped, one is able to reduce the valuation of a 2‐Bermudan swaption to a single numerical integration at the first expiry date. In that integration the most complex part of the embedded European swaptions valuation has been simplified to perform it only once and not for every point. In a special but very common in practice case, a semi‐explicit formula is provided. Those results lead to a significantly faster and more precise implementation of swaption valuation. The improvements extend even more favourably to sensitivity calculations.