Vicente Vera

Applying soft computing techniques to optimise a dental milling process

This study presents a novel soft computing procedure based on the application of artificial neural networks, genetic algorithms and identification systems, which makes it possible to optimise the implementation conditions in the manufacturing process of high precision parts, including finishing precision, while saving both time and financial costs and/or energy. This novel intelligent procedure is based on the following phases. Firstly, a neural model extracts the internal structure and the relevant features of the data set representing the system. Secondly, the dynamic system performance of different variables is specifically modelled using a supervised neural model and identification techniques. This constitutes the model for the fitness function of the production process, using relevant features of the data set. Finally, a genetic algorithm is used to optimise the machine parameters from a non parametric fitness function. The proposed novel approach was tested under real dental milling processes using a high-precision machining centre with five axes, requiring high finishing precision of measures in micrometres with a large number of process factors to analyse. The results of the experiment, which validate the performance of the proposed approach, are presented in this study.

Effects of curcumin on the proliferation and mineralization of human osteoblast-like cells: implications of nitric oxide.

Curcumin (diferuloylmethane) is found in the rhizomes of the turmeric plant (Curcuma longa L.) and has been used for centuries as a dietary spice and as a traditional Indian medicine used to treat different conditions. At the cellular level, curcumin modulates important molecular targets: transcription factors, enzymes, cell cycle proteins, cytokines, receptors and cell surface adhesion molecules. Because many of the curcumin targets mentioned above participate in the regulation of bone remodeling, curcumin may affect the skeletal system. Nitric oxide (NO) is a gaseous molecule generated from l-arginine during the catalization of nitric oxide synthase (NOS), and it plays crucial roles in catalization and in the nervous, cardiovascular and immune systems. Human osteoblasts have been shown to express NOS isoforms, and the exact mechanism(s) by which NO regulates bone formation remain unclear. Curcumin has been widely described to inhibit inducible nitric oxide synthase expression and nitric oxide production, at least in part via direct interference in NF-κB activation. In the present study, after exposure of human osteoblast-like cells (MG-63), we have observed that curcumin abrogated inducible NOS expression and decreased NO levels, inhibiting also cell prolifieration. This effect was prevented by the NO donor sodium nitroprusside. Under osteogenic conditions, curcumin also decreased the level of mineralization. Our results indicate that NO plays a role in the osteoblastic profile of MG-63 cells.

MicroCBR: A case-based reasoning architecture for the classification of microarray data

Microarray technology provides a great amount of data requiring analysis, and the use of new intelligent algorithms that identify the relevant information for the classification process has become essential. This study presents a classification tool called MicroCBR that uses the case-based reasoning paradigm and incorporates a novel filtering technique based on statistical methods, a new clustering technique that uses ESOINN (Enhanced Self-Organizing Incremental Neuronal Network), and a knowledge extraction technique based on the J48 algorithm. MicroCBR has been applied to classify 91 CLL patients and the results obtained are shown in this paper.

A bio-inspired computational high-precision dental milling system

A novel bio-inspired computational high-precision dental milling system is proposed in this interdisciplinar research. The system applies several bio-inspired models, based on unsupervised learning, that analyse and identify the most relevant features of high-precision dental-milling data sets and their internal structures. Finally, a supervised neural architecture and certain identification techniques are applied, in order to model and to optimize the high-precision process. This is done by empirically testing the model using a real data set taken from a dynamic high-precision machining centre with five axes.

Optimizing a dental milling process by means of soft computing techniques

A novel soft computing system to optimize a dental milling process is proposed. The model is based on the initial application of several statistical and projection methods as Principal Component Analysis and Cooperative Maximum Likelihood Hebbian Learning to analyze the structure of the data set and to identify the most relevant variables. Finally, a supervised neural model and identification techniques are applied, in order to model the process and optimize it. In this study a real data set obtained by a dynamic machining center with five axes simultaneously is analyzed to empirically test the novel system in order to optimize the time error.

Segmental fat-free and fat mass measurements by bioelectrical impedance analysis in 2,224 healthy spanish women aged 18–85 years

This study provides updated data on body composition in adult Spanish women.

Lack of association of vitamin D receptor BsmI gene polymorphism with bone mineral density in Spanish postmenopausal women

Osteoporosis is a polygenic disorder that is determined by the effects of several genes, each with relatively modest effects on bone mass. The aim of this study was to determine whether the vitamin D receptor single nucleotide polymorphism BsmI is associated with bone mineral density (BMD) in Spanish postmenopausal women. A total of 210 unrelated healthy postmenopausal women aged 60 ± 8 years were genotyped using TaqMan® SNP Genotyping Assays. Lumbar and femoral BMD were determined by dual-energy X-ray absorptiometry (DEXA). Daily calcium and vitamin D intake were determined by a food questionnaire. No differences were found in the femoral neck, trochanter, Ward’s Triangle, L2, L3, L4, L2-L4, or between the femoral neck and total hip BMD after further adjustment for potential confounding factors (P > 0.05) (age, BMI, years since menopause and daily calcium intake). The BsmI polymorphism in the VDR gene was not associated with BMD in Spanish postmenopausal women.

A novel hybrid intelligent system for multi-objective machine parameter optimization

This multidisciplinary research presents a novel hybrid intelligent system to perform a multi-objective industrial parameter optimization process. The intelligent system is based on the application of evolutionary and neural computation in conjunction with identification systems, which makes it possible to optimize the implementation conditions in the manufacturing process of high precision parts, including finishing precision, while saving time, financial costs and/or energy. Empirical verification of the proposed hybrid intelligent system is performed in a real industrial domain, where a case study is defined and analyzed. The experiments are carried out based on real dental milling processes using a high precision machining centre with five axes, requiring high finishing precision of measures in micrometers with a large number of process factors to analyze. The results of the experiments which validate the performance of the proposed approach are presented in this study.

Greater Calcium Intake is Associated with Better Bone Health Measured by Quantitative Ultrasound of the Phalanges in Pediatric Patients Treated with Anticonvulsant Drugs

We aimed to investigate and compare the effects of chronic antiepileptic therapy on bone health in pediatric patients using quantitative ultrasound of the phalanges (QUS) and controlling for potential confounding factors, particularly nutrient intake. The amplitude-dependent speed of sound (Ad-SoS) was measured in 33 epileptic children and 32 healthy children aged 6.5 ± 3.1 and 6.3 ± 1.1 (mean ± SD) years, respectively. There were no significant differences in the demographics such as age, weight and height between epileptic children and the control group children. None of the children in the epileptic or the treatment group were found to have a vitamin D deficiency. There were no significant differences in laboratory tests between groups. Lower QUS figures were found in the epileptic children (p = 0.001). After further adjustment for potential confounders such age, height, weight, calcium intake, vitamin D intake, physical activity and sex, the differences remained significant (p < 0.001). After further classification of the participants based on the tertile of calcium intake, no significant differences were found between patients and healthy controls in the greatest tertile of calcium intake (p = 0.217). We conclude that anticonvulsant therapy using valproate may lead to low bone mass in children and that an adequate intake of calcium might counteract such deleterious effects.

Lack of Influence of Vitamin D Receptor BsmI (rs1544410) Polymorphism on the Rate of Bone Loss in a Cohort of Postmenopausal Spanish Women Affected by Osteoporosis and Followed for Five Years

A longitudinal study was conducted to investigate the relation between a polymorphism in the vitamin D receptor (VDR) gene and changes in bone mineral density (BMD) and quantitative ultrasound of the phalanges (QUS) over a five-year period. The subjects were 456 postmenopausal women with osteoporosis undergoing treatment, aged 59.95±7.97 years (mean±standard deviation [SD]) at baseline. BMD was measured at the hips and lumbar spine by dual-energy X-ray absorptiometry, and QUS was measured by means of amplitude-dependent speed of sound (Ad-SoS) at the phalanges. Lifestyle information was obtained via a questionnaire. The genotype frequencies of the BsmI (rs1544410) gene polymorphism were 29.4%, 47.1%, and 23.5% for bb, Bb, and BB, respectively. After five years, BMD (annual change in %/year) at the femoral neck (FN) showed a significant modification based on the rs1544410 genotype (BB vs Bb); there was an overall decrease in bone mass (-0.70±2.79%/year; P = 0.025). An analysis of covariance with adjustments for age, weight, height, percentage of weight change per year, baseline BMD and calcium intake showed that the observed associations were no longer significant (P = 0.429). No significant associations were found between the QUS measurements and the rs1544410 genotype after the five-year period. Our study limitations includes lack of information about type and length of duration of the osteoporosis treatment. Our results indicate that rs1544410 polymorphisms do not account significantly for the changes in bone mass in Spanish women with osteoporosis undergoing treatment.