Functional and environmental performance of plant-produced crumb rubber asphalt mixtures using the dry process

Incorporating crumb rubber (CR) using the dry process, directly in the asphalt mixture rather than into the bituminous binder requires no plant retrofitting, and therefore is the most practical industrial method for CR incorporation into asphalt mixtures. Nevertheless, very few large scale studies have been conducted. This work uses a holistic approach and reports on the functional and environmental performance of asphalt mixtures with different concentrations of CR fabricated employing the dry process in asphalt plants. Gaseous emissions were monitored during the production and laboratory leaching tests simulating the release of pollutants during rain, was conducted to evaluate the toxicology of both the CR material alone and the modified asphalt mixtures. In addition, laboratory compacted samples were tested to assess their fatigue behavior. Furthermore, noise relevant surface properties of large roller compacted slabs were evaluated before and after being subjected to a load simulator (MMLS3) to evaluate their resistance to permanent deformation. The results confirm that comparable performance can be achieved with the incorporation of CR using the dry process for high performance surfaces such as semi-dense asphalt, which usually require the use of polymer modified binders. Environmental performance improvement can be achieved by a washing step of the CR material that could remove polar CR additives which have commonly been used as vulcanization accelerator during rubber production.

Concomitant behavior of arsenic and selenium from the karst infillings materials of the fractured carbonate Dogger Aquifer (Hydrogeological Experimental Site, Poitiers, France)

Petrographic and mineralogical analyses combined with sequential extractions and leaching experiments as a function of pH were performed on black clayey sediments fulfilling karsts in the Hydrogeological Experimental Site (HES) of Poitiers (France) to investigate the behavior of arsenic and selenium in a fractured limestone aquifer. Sequential extractions showed that arsenic is mainly associated with pyrite (about 35%) and secondary iron oxyhydroxides (around 13%), along with a substantial exchangeable fraction (about 13%). The soluble fraction and the fraction associated to organic matter are ∼2% and ∼5%, respectively. The distribution of selenium is mainly pyritic (around 39%) or associated with organic matter (about 18%). Its association to secondary iron oxyhydroxides minerals is low (around 2%), whereas its soluble fraction is around 5%. SEM analyses revealed the presence of arsenic "hot spots" into euhedral pyrite crystals surrounded by a halo of iron oxyhydroxides resulting from their alteration, and both are enriched with arsenic. Selenium has a similar pyritic origin but after alteration, it is predominantly associated with organic matter. Despite different distributions, the leaching experiment as a function of pH showed that the mobilization of arsenic and selenium overlapped below pH 2 and above pH 8. The main differences were observed between pH 2 and 8 with a plateau at 5% of released selenium, whereas the amount of mobilized arsenic continuously decreased. The pH-dependence of both elements is attributed to the partial dissolution of pyrite in acidic conditions combined with desorption processes at higher pH values.

High Performance Liquid Chromatographic Determination of Carbohydrates in Chocolate: Collaborative Study

A collaborative study determining sucrose, glucose, fructose, maltose, and lactose in chocolate products was conducted using a previously published high performance liquid chromatographic (HPLC) method. Five samples (2 milk chocolates, 1 dark chocolate, 1 powdered mix, and 1 sirup) were analyzed in duplicate by 7 collaborators. The results indicate adequate method precision. In addition, the HPLC method allows for the simultaneous determination of 5 saccharides in chocolate products in 15 min. The method has been adopted as official first action.

Vitamin D in Infant Formula and Enteral Products by Liquid Chromatography: Collaborative Study

Results from a collaborative study of a new liquid chromatographic (LC) method for determination ofvitamin D in infant formulas and enteral products are presented. Each of 15 laboratories was provided with 11 blind duplicate samples covering a range ofapproximately 200-500 International Units/quart (normal dilution), a system suitability sample, and the U.S. Pharmacopeia ergo- and cholecalciferol standards. Product types included liquid and powder forms of milk (whey and casein), soy, and hydrolyzed protein-based infant formulas and enteral products. The method includes a single liquid-liquid extraction following saponification, solid-phase extraction,and then concentration by evaporation. An isocratic, nonaqueous, chromatographic system with reversed-phase, zero end- capped C18 column, and UV detector set at 265 nm are used. Statistical evaluation ofdata from participating laboratories showthe average reproducibility and repeatability of the method across all samples to be excellent, with RSDR and RSDr values of 13.48 and 9.44, respectively, after elimination of out liers. The LC method for determination of vitamin D in infant formulas and enteral products has been adopted by AOAC INTERNATIONAL.

ASSESSING THE CONTRIBUTION OF CROSS-SECTIONS TO THE UNCERTAINTY OF MONTE CARLO CALCULATIONS IN MICRO- AND NANODOSIMETRY

Within EURADOS Working Group 6 'Computational Dosimetry', the micro and nanodosimetry task group 6.2 has recently conducted a Monte Carlo (MC) exercise open to participants around the world. The aim of this exercise is to quantify the contribution to the uncertainty of micro and nanodosimetric simulation results arising from the use of different electron-impact cross-sections, and hence physical models, employed by different MC codes (GEANT4-DNA, PENELOPE, MCNP6, FLUKA, NASIC and PHITS). Comparison of the participants' simulation results for both micro and nanodosimetric quantities using different MC codes was the first step of the exercise. The deviation between results is due to different cross-sections but also different tracking methods and particle transport cut-off energies. The second step of the exercise will involve using identical cross-section datasets to account only for the other variations in the first step, thus enabling the determination of the uncertainty contribution due to different cross-sections. This paper presents a comparison of the MC simulation results obtained in the first part of the exercise. For the microdosimetric simulations, particularly in the configuration where the electron source is contained within the micrometric target, the choice of MC code has a small influence on the results. For the nanodosimetric results, on the other hand, the mean ionisation cluster size distribution (ICSD) was sensitive to the physical models used in the MC codes. The ICSD was therefore chosen to study the influence of different cross-section data on the uncertainty of simulation results.

A New Standard DNA Damage (SDD) Data Format

Our understanding of radiation-induced cellular damage has greatly improved over the past few decades. Despite this progress, there are still many obstacles to fully understand how radiation interacts with biologically relevant cellular components, such as DNA, to cause observable end points such as cell killing. Damage in DNA is identified as a major route of cell killing. One hurdle when modeling biological effects is the difficulty in directly comparing results generated by members of different research groups. Multiple Monte Carlo codes have been developed to simulate damage induction at the DNA scale, while at the same time various groups have developed models that describe DNA repair processes with varying levels of detail. These repair models are intrinsically linked to the damage model employed in their development, making it difficult to disentangle systematic effects in either part of the modeling chain. These modeling chains typically consist of track-structure Monte Carlo simulations of the physical interactions creating direct damages to DNA, followed by simulations of the production and initial reactions of chemical species causing so-called "indirect" damages. After the induction of DNA damage, DNA repair models combine the simulated damage patterns with biological models to determine the biological consequences of the damage. To date, the effect of the environment, such as molecular oxygen (normoxic vs. hypoxic), has been poorly considered. We propose a new standard DNA damage (SDD) data format to unify the interface between the simulation of damage induction in DNA and the biological modeling of DNA repair processes, and introduce the effect of the environment (molecular oxygen or other compounds) as a flexible parameter. Such a standard greatly facilitates inter-model comparisons, providing an ideal environment to tease out model assumptions and identify persistent, underlying mechanisms. Through inter-model comparisons, this unified standard has the potential to greatly advance our understanding of the underlying mechanisms of radiation-induced DNA damage and the resulting observable biological effects when radiation parameters and/or environmental conditions change.

Property income from-whom-to-whom matrices: A dataset based on financial assets-liabilities stocks of financial instrument for Spain

A common problem in compiling and updating Social Accounting Matrices (SAM) or Input-Output tables is that of incomplete information. In the case of the submatrix ‘Property Income of the Account Allocation of Primary Income’, the information published by the National Bureau of Statistics of Spain (INE) is limited because it is not possible to build the set of from-whom-to-whom sub-matrix on income interest, dividends, securities and rents with only the subtotals presented in the Integrated Economic Accounts (IEA). This because the income distribution received and paid for by each institutional sector required for a financial SAM is not available, i.e. the INE does not break down the data by institutional destination and source. In this sense, our contribution rely on estimating a complete series of from-whom-to-whom matrices of Property Income for the Spanish economy between 1999 and 2016, in which we have devoted special attention to staying in line with the Data Gaps Initiative (DGI-2) recommendation released by the Financial Stability Board (FSB) and the International Monetary Fund (IMF), claiming that more focus is needed on data sets that support the monitoring of risks in the financial sector in response to regulatory and macro-financial emerging policy needs).

Influence of lane departure warnings onset and reliability on car drivers' behaviors

Lane departures represent an important cause of road crashes. The objective of the present study was to assess the effects of an auditory Lane Departure Warning System (LDWS) for partial and full lane departures (onset manipulation) combined with missed warnings (reliability manipulation: 100% reliable, 83% reliable and 66% reliable) on drivers' performances and acceptance. Several studies indicate that LDWS improves drivers' performances during lane departure episodes. However, little is known about the effects of the warning onset and reliability of LDWS. Results of studies which looked at forward collision warning systems show that early warnings tend to improve drivers' performances and receive a better trust judgement from the drivers when compared to later warnings. These studies also suggest that reliable assistances are more effective and trusted than unreliable ones. In the present study, lane departures were brought about by means of a distraction task whilst drivers simulated driving in a fixed-base simulator with or without an auditory LDWS. Results revealed steering behaviors improvements with LDWS. More effective recovery maneuvers were found with partial lane departure warnings than with full lane departure warnings and assistance unreliability did not impair significantly drivers' behaviors. Regarding missed lane departure episodes, drivers were found to react later and spend more time out of the driving lane when compared to properly warned lane departures, as if driving without assistance. Subjectively, LDWS did not reduce mental workload and partial lane departure warnings were judged more trustworthy than full lane departure ones. Data suggests the use of partial lane departure warnings when designing LDWS and that even unreliable LDWS may draw benefits compared to no assistance.

Assessment of an action against environmental noise: Acoustic durability of a pavement surface with crumb rubber

Environmental noise is a worldwide problem that has an adverse effect in the quality of life of urban population. Some work has shown that there is a correlation between environmental noise and health issues as sleep disturbance or annoyance. This study presents the time evolution of a test track fabricated with an asphalt mixture with 20% of crumb rubber by weight of bitumen, added by the wet process. A complete surface characterization has been performed by determining tire/pavement sound levels, road texture profiles, in-situ dynamic stiffness and sound absorption of compacted and extracted sample cores. Two measurement campaigns were performed: just after mixture laying and after 3 years in service. This study confirms that the use of crumb rubber as a modifier of bituminous binders (CRMB) can improve the pavement characteristics: gap-graded mixtures with crumb rubber can be used in the action plans as urban rehabilitation measure to fight noise pollution. However, this noise reduction seems to decrease with age at a rate of approximately 0.15 dB(A) per year.

Physical Activity Is Associated with Attention Capacity in Adolescents

OBJECTIVE

To assess the relationships among physical activity, measured objectively, and attention capacity in European adolescents.

STUDY DESIGN

The study included 273 adolescents, aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Participants wore a uniaxial accelerometer for 7 days to measure physical activity. The d2 Test of Attention was administered to assess attention capacity. Multivariate analyses were used to study the association of attention capacity with each measure of physical activity. Receiver operating characteristic analysis was performed to determine thresholds that best discriminate between low and good attention capacity.

RESULTS

After controlling for potential confounding variables (age, sex, body mass index, parental educational level, fat mass, aerobic fitness, and center), adolescents' attention capacity test performances were significantly and positively associated with longer time spent in moderate or moderate-to-vigorous physical activity (MVPA) in free-living conditions (P < .05). Receiver operating characteristic curve analyses revealed that the physical activity thresholds that best discriminated between low/good attention capacities were ≥41 min·day(-1) for moderate, ≥12 min·day(-1) for vigorous, and ≥58 min·day(-1) for MVPA.

CONCLUSION

These findings suggest that promoting MVPA may be have a beneficial effect on attention capacity, an important component of cognition, in adolescents.

An algorithm to assess the need for clinical Monte Carlo dose calculation for small proton therapy fields based on quantification of tissue heterogeneity

PURPOSE

In proton therapy, complex density heterogeneities within the beam path constitute a challenge to dose calculation algorithms. This might question the reliability of dose distributions predicted by treatment planning systems based on analytical dose calculation. For cases in which substantial dose errors are expected, resorting to Monte Carlo dose calculations might be essential to ensure a successful treatment outcome and therefore the benefit is worth a presumably long computation time. The aim of this study was to define an indicator for the accuracy of dose delivery based on analytical dose calculations in treatment planning systems for small proton therapy fields to identify those patients for which Monte Carlo dose calculation is warranted.

METHODS

Fourteen patients treated at our facility with small passively scattered proton beams (apertures diameters below 7 cm) were selected. Plans were generated in the XiO treatment planning system in combination with a pencil beam algorithm developed at the Massachusetts General Hospital and compared to Monte Carlo dose calculations. Differences in the dose to the 50% of the gross tumor volume (D50, GTV) were assessed in a field-by-field basis. A simple and fast methodology was developed to quantify the inhomogeneity of the tissue traversed by a single small proton beam using a heterogeneity index (HI)-a concept presented by Plugfelder et al. [Med. Phys. 34, 1506-1513 (2007)] for scanned proton beams. Finally, the potential correlation between the error made by the pencil beam based treatment planning algorithm for each field and the level of tissue heterogeneity traversed by the proton beam given by the HI was evaluated.

RESULTS

Discrepancies up to 5.4% were found in D50 for single fields, although dose differences were within clinical tolerance levels (<3%) when combining all of the fields involved in the treatment. The discrepancies found for each field exhibited a strong correlation to their associated HI-values (Spearman's ρ=0.8, p<0.0001); the higher the level of tissue inhomogeneities for a particular field, the larger the error by the analytical algorithm. With the established correlation a threshold for HI can be set by choosing a tolerance level of 2-3%-commonly accepted in radiotherapy.

CONCLUSIONS

The HI is a good indicator for the accuracy of proton field delivery in terms of GTV prescription dose coverage when small fields are delivered. Each HI-value was obtained from the CT image in less than 3 min on a computer with 2 GHz CPU allowing implementation of this methodology in clinical routine. For HI-values exceeding the threshold, either a change in beam direction (if feasible) or a recalculation of the dose with Monte Carlo would be highly recommended.

Fasting plasma peptide YY concentrations are increased in patients with major depression who associate weight loss

BACKGROUND

Many patients with major depression refer a decreased appetite and weight loss among their symptoms. Peptide YY (PYY) and ghrelin belong to the family of peptides of the gut-brain axis implicated in the regulation of appetite and energy metabolism. PYY stimulates a powerful central satiety response and ghrelin increases food intake and weight gain. Brain-derived neurotrophic factor (BDNF) also contributes to the central control of food intake as an anorexigenic factor.

AIM

To study fasting plasma total and acylated ghrelin, plasma PYY and serum BDNF levels in patients with major depression with weight loss as one of their symptoms and compare them with matched healthy controls.

SUBJECTS AND METHODS

Fifteen adult patients, 9 male and 6 female, with recent diagnosis of major depression, and 16 healthy adult subjects, matched by age and anthropometric parameters were studied. All depressed patients referred weight loss and were not under antidepressant therapy. Fasting total PYY, total ghrelin and acylated ghrelin and BDNF were determined.

RESULTS

Fasting total PYY was higher in patients than controls (2.01±0.09 vs 1.29±0.16 pmol/l). There were no differences in fasting total ghrelin, acylated ghrelin or BDNF levels.

CONCLUSIONS

Major depressed patients, with weight loss at diagnosis, showed higher fasting plasma PYY levels that could contribute to their reduced appetite.

MO-F-BRB-03: A Method to Assess the Need for Clinical Monte Carlo Dose Calculations for Small Proton Therapy Fields

PURPOSE

Due to multiple Coulomb scattering in complex geometries, small field dosimetry in proton therapy is challenging. Our goal was to define an indicator for the accuracy of dose delivery based on analytical dose calculations in treatment planning systems for small (e.g. radiosurgery) proton therapy fields.

METHODS

Seven patients whose treatment involved one or more small fields (below ∼3.6cm in diameter) were selected. We developed a fast methodology to quantify the inhomogeneity of the tissue traversed by a single beam using a heterogeneity index (HI). The implementation was based on the dose calculation approach taken by our pencil beam algorithm. Plans created with the treatment planning system were verified against Monte Carlo dose calculations on a field- by-field basis. DVHs were analyzed and differences in the dose to the GTV were assessed. The correlation between the HI-values and the discrepancies between planning system and Monte Carlo in terms of absolute dose to the target was studied.

RESULTS

Our treatment planning system overestimates the dose within the GTV for very small fields by up to ∼8%, even if proper output factor normalization is done in water. The differences are strongly correlated to HI (Spearman's ρ=0.8, rho<0.0001). More complex heterogeneities within the beam path caused larger errors by the analytical algorithm. With the established correlation a threshold for the HI can be set by choosing a tolerance level.

CONCLUSIONS

The HI as defined in this study appears to be a good indicator of the accuracy of proton field delivery in terms of GTV prescription dose when small fields are being delivered. Each HI-value was obtained in less than 2 minutes allowing implementation of the HI algorithm in clinical routine. For HI- values exceeding a certain threshold, either a change in beam incidence or a Monte Carlo dose calculation should be considered.

Leads for antitubercular compounds from kinase inhibitor library screens

Discovering new drugs to treat tuberculosis more efficiently and to overcome multidrug resistance is a world health priority. To find antimycobacterial scaffolds, we screened a kinase inhibitor library of more than 12,000 compounds using an integrated strategy involving whole cell-based assays with Corynebacterium glutamicum and Mycobacterium tuberculosis, and a target-based assay with the protein kinase PknA. Seventeen "hits" came from the whole cell-based screening approach, from which three displayed minimal inhibitory concentrations (MIC) against M. tuberculosis below 10μM and were non-mutagenic and non-cytotoxic. Two of these hits were specific for M. tuberculosis versus C. glutamicum and none of them was found to inhibit the essential serine/threonine protein kinases, PknA and PknB present in both bacteria. One of the most active hits, VI-18469, had a benzoquinoxaline pharmacophore while another, VI-9376, is structurally related to a new class of antimycobacterial agents, the benzothiazinones (BTZ). Like the BTZ, VI-9376 was shown to act on the essential enzyme decaprenylphosphoryl-β-D-ribose 2'-epimerase, DprE1, required for arabinan synthesis.

The pollutant diethylhexyl phthalate regulates hepatic energy metabolism via species-specific PPARalpha-dependent mechanisms

BACKGROUND

The modulation of energetic homeostasis by pollutants has recently emerged as a potential contributor to the onset of metabolic disorders. Diethylhexyl phthalate (DEHP) is a widely used industrial plasticizer to which humans are widely exposed. Phthalates can activate the three peroxisome proliferator-activated receptor (PPAR) isotypes on cellular models and induce peroxisome proliferation in rodents.

OBJECTIVES

In this study, we aimed to evaluate the systemic and metabolic consequences of DEHP exposure that have remained so far unexplored and to characterize the underlying molecular mechanisms of action.

METHODS

As a proof of concept and mechanism, genetically engineered mouse models of PPARs were exposed to high doses of DEHP, followed by metabolic and molecular analyses.

RESULTS

DEHP-treated mice were protected from diet-induced obesity via PPARalpha-dependent activation of hepatic fatty acid catabolism, whereas the activity of neither PPARbeta nor PPARgamma was affected. However, the lean phenotype observed in response to DEHP in wild-type mice was surprisingly abolished in PPARalpha-humanized mice. These species differences are associated with a different pattern of coregulator recruitment.

CONCLUSION

These results demonstrate that DEHP exerts species-specific metabolic actions that rely to a large extent on PPARalpha signaling and highlight the metabolic importance of the species-specific activation of PPARalpha by xenobiotic compounds.

Evolutionary origin and functions of retrogene introns

Retroposed genes (retrogenes) originate via the reverse transcription of mature messenger RNAs from parental source genes and are therefore usually devoid of introns. Here, we characterize a particular set of mammalian retrogenes that acquired introns upon their emergence and thus represent rare cases of intron gain in mammals. We find that although a few retrogenes evolved introns in their coding or 3' untranslated regions (untranslated region, UTR), most introns originated together with untranslated exons in the 5' flanking regions of the retrogene insertion site. They emerged either de novo or through fusions with 5' UTR exons of host genes into which the retrogenes inserted. Generally, retrogenes with introns display high transcription levels and show broader spatial expression patterns than other retrogenes. Our experimental expression analyses of individual intron-containing retrogenes show that 5' UTR introns may indeed promote higher expression levels, at least in part through encoded regulatory elements. By contrast, 3' UTR introns may lead to downregulation of expression levels via nonsense-mediated decay mechanisms. Notably, the majority of retrogenes with introns in their 5' flanks depend on distant, sometimes bidirectional CpG dinucleotide-enriched promoters for their expression that may be recruited from other genes in the genomic vicinity. We thus propose a scenario where the acquisition of new 5' exon-intron structures was directly linked to the recruitment of distant promoters by these retrogenes, a process potentially facilitated by the presence of proto-splice sites in the genomic vicinity of retrogene insertion sites. Thus, the primary role and selective benefit of new 5' introns (and UTR exons) was probably initially to span the often substantial distances to potent CpG promoters driving retrogene transcription. Later in evolution, these introns then obtained additional regulatory roles in fine tuning retrogene expression levels. Our study provides novel insights regarding mechanisms underlying the origin of new introns, the evolutionary relevance of intron gain, and the origin of new gene promoters.

Sealing ability, water sorption, solubility and toothbrushing abrasion resistance of temporary filling materials

AIM

To evaluate marginal seal, water sorption, solubility and loss of mass after brushing of several temporary filling materials.

METHODOLOGY

For marginal seal, Class I cavities, including endodontic access preparations, were made in human molar teeth and restored using one or other of several temporary filling materials (n = 10): zinc oxide/calcium sulphate-based cement (Cavit, 3M,ESPE, St. Paul, MN, USA), zinc oxide/eugenol cement (IRM, Dentsply Caulk, Milford, DE, USA), glass ionomer cement (Vidrion R, SSWhite, Rio de Janeiro, RJ, Brazil) or a dimethacrylate-based filling (Bioplic, Biodinâmica, Londrina, PR, Brazil). Dye penetration was assessed after thermocycling and immersion in 0.5% basic fuchsine solution. For water sorption, solubility and loss of mass analyses, disc-shaped specimens were made. Water sorption and solubility were evaluated by mass alteration after storage in distilled water for 7 days (n = 7). Loss of mass was calculated based on the difference of mass after abrasion with a toothbrush (n = 5), and surfaces were analysed by SEM. Data of water sorption, solubility and loss of mass were submitted to anova and Tukey's test, and marginal sealing data to Kruskal-Wallis test (P < 0.05).

RESULTS

Statistically significant differences were observed for marginal sealing (P < 0.0001), water sorption (P < 0.01), solubility (P < 0.01) and loss of mass (P < 0.05). Bioplic had the best marginal seal. Cavit had the greatest water sorption and solubility. Vidrion R and Bioplic had the lowest solubility. Loss of mass after brushing was higher for Cavit, followed by Bioplic, IRM and Vidrion R. Cavit and Vidrion R were worn aggressively by brushing.

CONCLUSIONS

The resin-based temporary filling Bioplic produced the best marginal seal, and was associated with the lowest water sorption, solubility and loss of mass.

Truncal and abdominal fat as determinants of high triglycerides and low HDL-cholesterol in adolescents

We examined whether abdominal and truncal adiposity, assessed with simple anthropometric indices, determines serum triglycerides and high-density lipoprotein (HDL)-cholesterol levels independently of total adiposity amount in adolescents. A total of 547 Spanish adolescents (284 males and 263 females) aged 13-18.5 years were included in this study. Measures of truncal adiposity included subscapular to triceps ratio, and trunk-to-total skinfolds ratio (TTS%). Waist circumference was used as a surrogate of abdominal adiposity, and BMI was used as a measure of total adiposity. The results of the regression models indicated that levels of triglycerides were positively associated with waist circumference and TTS% after controlling for age and Tanner stage in both sexes. Once BMI was entered in the model, these associations remained significant for waist circumference in females. HDL-cholesterol levels were negatively associated with waist circumference in both sexes, and with subscapular to triceps ratio and TTS% in males, after controlling for age and Tanner stage. Once BMI was entered in the model, these associations remained significant for subscapular to triceps ratio and for TTS% in males. The results of this study suggest that in male adolescents, truncal adiposity is negatively associated with levels of HDL-cholesterol, whereas in females, abdominal adiposity is positively associated with levels of triglycerides independently of total adiposity. These findings highlight the deleterious effect of both truncal and abdominal fat depots on the lipid profile already from the first decades of life.

Impact of normalization on miRNA microarray expression profiling

Profiling miRNA levels in cells with miRNA microarrays is becoming a widely used technique. Although normalization methods for mRNA gene expression arrays are well established, miRNA array normalization has so far not been investigated in detail. In this study we investigate the impact of normalization on data generated with the Agilent miRNA array platform. We have developed a method to select nonchanging miRNAs (invariants) and use them to compute linear regression normalization coefficients or variance stabilizing normalization (VSN) parameters. We compared the invariants normalization to normalization by scaling, quantile, and VSN with default parameters as well as to no normalization using samples with strong differential expression of miRNAs (heart-brain comparison) and samples where only a few miRNAs are affected (by p53 overexpression in squamous carcinoma cells versus control). All normalization methods performed better than no normalization. Normalization procedures based on the set of invariants and quantile were the most robust over all experimental conditions tested. Our method of invariant selection and normalization is not limited to Agilent miRNA arrays and can be applied to other data sets including those from one color miRNA microarray platforms, focused gene expression arrays, and gene expression analysis using quantitative PCR.

Toward the acoustical characterization of asphalt pavements: analysis of the tire/road sound from a porous surface

Sound level in close proximity to the contact patch of the tire and road (L(CPtr)) is analyzed as a function of the vehicle speed in the acoustic frequency range, showing different behavior depending on frequency. At least two regions are observed; one at low frequencies, where the variation in sound with speed (coefficient B) increases with frequency, and the other at higher frequencies, where such sound/speed variation does not increase significantly with frequency. The dependence of B at low frequencies seems to be correlated with the high sound absorption of this porous surface.

Biologic diversity of polyomavirus BK genomic sequences: Implications for molecular diagnostic laboratories

Data on polyomavirus genomic diversity has greatly expanded in the past few years. The implications of viral DNA sequence variation on the performance of molecular diagnostic assays have not been systematically examined. 716 BK, 1626 JC, and 73 SV40 virus sequences available in GenBank were aligned using Clustal-X. Five different published BKV PCR assays currently in use at major medical centers were evaluated for primer and probe mismatches with available GenBank sequences. Coverage of naturally occurring BKV strains varied amongst different assay methods. Targeted viral sequences showed major mismatch with primer or probe sequence in up to 30.7% of known BKV strains. BKV subtypes IVa, IVb, and IVc were more prone to this problem, reflecting common use of Type I Dun sequence for assay design. Despite the known polymorphism of this gene, 484 VP-1 sequences with conserved areas potentially suitable for PCR assay design are available. Assay targets in the Large T-antigen and agnogene are less subject to genetic variation, but sequence information corresponding to the latter two genes is available only for 164 and 174 published strains, respectively. Cross reactivity of appropriately selected BKV primers with JCV and SV40 sequences available in current databases was not a significant problem.

Metabolic risk-factor clustering estimation in obese children

The purpose of this study was to apply the new approach for Metabolic Individual Risk-factor And Clustering Estimation (MIRACLE) score in a group of Spanish obese children and adolescents and to describe its relationship with other metabolic risk factors. 153 children with simple obesity were studied: 79 males and 74 females, mean age 11.2 +/- 2.2. Obesity was defined when BMI was higher than the age and sex specific equivalent to 30 kg/m2 in adults. MIRACLE score included: family history (early cardiovascular disease, type 2 diabetes, and hypertension), individual history (small for gestational age and ethnic origin), clinical features (BMI, waist circumference > 90th percentile and blood pressure > 95th percentile) and metabolic abnormalities (glucose intolerance or type 2 diabetes). It was assigned a value of 1 to "presence" and 0 to" absence" in every patient. The children were considered as having metabolic risk when at least 5 items were present. Triglycerides, HDL-cholesterol, apolipoprotein B, apolipoprotein A1, glucose and HOMA index, were measured too. The most frequent clinical features of MIRACLE score were: excess waist circumference (95.4%) and hypertension (41.8%). Family history criteria were frequent (55.3% for type 2 diabetes, 39.1% for hypertension and 31.3% for early cardiovascular disease). Individual risk factors were not frequent. Glucose intolerance was detected in 22.2% of the obese patients. A MIRACLE score > or = 5 was found in 37.4% of the children studied, being associated with a significant risk of dyslipidemia (triglycerides, p = 0.040; HDL-cholesterol, p = 0.006; LDL-cholesterol p = 0.038; apolipoprotein B, p = 0.008) only in females. In conclusion, the MIRACLE score is useful in order to detect metabolic risk in obese children but it seems necessary to improve the score, by including other features of the metabolic syndrome like lipid profile or indirect indicators of insulin resistance.

Small birth weight and later body composition and fat distribution in adolescents: the Avena study

OBJECTIVE

To assess the association between birth weight and body composition and fat distribution in adolescents, and to test the possible sex-specific effect in these relationships.

METHODS AND PROCEDURES

A total of 1,223 adolescents 13-18.5 years old (553 male adolescents and 670 female adolescents) born at >35 weeks, were selected from a cross-sectional multicenter study conducted in five Spanish cities in 2000-2002. BMI was calculated from weight and height. Triceps and subscapular skinfold thickness (ST) were measured on the left side, and fat mass (FM) and fat-free mass (FFM) were estimated according to the equations of Slaughter et al. Subscapular skinfold adjusted by tricipital (ST) and waist circumference were used as markers of central adiposity.

RESULTS

Birth weight Z-score was positively associated with FFM in female adolescents (P<0.001), but not in male adolescents, after controlling for age, pubertal stage, gestational age, socioeconomic status, physical activity, and current height (P<0.001 for interaction between adjusted birth weight Z-score and sex). Adjusted birth weight Z-score was inversely associated with central adiposity in male and female adolescents as measured by ST (P=0.026).

DISCUSSION

These results provide further evidence that gender has an important influence on the programming effect of birth weight on later FFM in adolescents because the effect was only observed in female adolescents. Our results suggest that small size for gestational age at birth could program more central subcutaneous fat deposition in adolescents of both sexes, but further research is needed on this issue.

Zinc supplementation in infants with asymmetric intra uterine growth retardation; effect on growth, nutritional status and leptin secretion

OBJECTIVES

To analyse the effect of zinc supplementation in growth and nutritional status of a homogeneous group of newborns with intra uterine growth retardation and asymmetric growth. The effect of changes of zinc status on growth and leptin serum concentrations was also analysed.

POPULATION AND METHODS

A double blind, randomised clinical trial was designed in order to detect differences in growth between zinc and placebo groups during the first 6 months of life. 31 infants were included either to the zinc group (n = 14) (38.8+/-1.4 weeks GA, 2,171+/-253 g body weight) or the placebo group (n = 17) (38.9+/-1.1 weeks GA, 2,249+/-220 g body weight). The zinc group received a supplement of 3 mg elemental zinc per day (as zinc sulphate).

RESULTS

There were not significant differences between groups for anthropometric measurements through the study period. We found a significant effect of the study group, in hair zinc concentrations, but not in serum zinc concentrations; post-hoc comparisons for hair zinc revealed that there were significant differences between groups at 1, 2, and 6 months of age. Changes in serum and hair zinc concentrations from baseline to 6 months, showed significant correlations with changes in weight/age and length/age z-scores, in the supplement group. Changes in leptin serum concentrations during follow-up, showed significant correlations with changes in sum of 4 skinfolds and weight/age z-score, in the placebo group. Changes in hair zinc concentration through the study period showed significant correlations with changes in leptin serum concentrations from baseline to 6 months of follow-up.

CONCLUSIONS

In a homogeneous group of intra uterine growth retardation infants with asymmetric growth, 3 mg/day zinc supplementation do not show significant improvements in weight and length growth. Changes in zinc status were related with changes in weight and length during the first 6 months of life. Changes in leptin serum concentrations were related with changes in the anthropometric indices of body fat accretion.

Assessment of asphalt concrete acoustic performance in urban streets

Geo-referenced close proximity rolling noise and sound absorption measurements are used for acoustical characterization of asphalt concrete surfaces in an urban environment. A close proximity noise map of streets with low speed limits is presented for a reference speed of 50 km/h. Different pavements and pavement conditions, common in urban streets, are analyzed: dense and semidense asphalt concrete, with Spanish denomination D-8 and S-12, respectively, and on the other hand, dense pavement at the end of its service life (D-8(*)). From the acoustics point of view, the most favorable surface, by more than 4 dB(A) compared with the S-12 mix, is the smoothest surface, i.e., the D-8 mix, even though it presents a minor absorption coefficient in normal incidence. Noise levels from dense surfaces (D-8) increase significantly over time, principally due to the appearance of surface defects such as cracks and ruts. Longitudinal variability of the close proximity tire/pavement noise emission and surface homogeneity are also analyzed.

Effect of the Ala12 allele in the PPARgamma-2 gene on the relationship between birth weight and body composition in adolescents: the AVENA study

The intent of this study was to assess whether the effect of birth weight on later body composition is modified by Pro12Pro, Pro12Ala, and Ala12Ala genotypes of the peroxisome proliferator-activated receptor gamma-2 (PPARgamma-2) gene. The PPARgamma-2 gene polymorphism was genotyped in 273 adolescents aged 13-18.5 y, born at term and whose birth weight was known. They were selected from a cross-sectional multicenter study conducted in five Spanish cities in 2000-2002. Body mass index (BMI) was calculated from weight and height measurements, and body composition and fat distribution were estimated from skinfold thickness. A total of 229 subjects (111 males and 118 females) carried the Pro12Pro genotype and 44 (22 males and 22 females) the Pro12Ala and Ala12Ala PPARgamma-2 genotypes. In the Pro12Pro group, birth weight Z score was positively associated with both fat-free mass (FFM) (p < 0.05) and fat mass (FM) (p < 0.05), but these relationships disappeared after controlling for age, gestational age, socioeconomic status (SES), physical activity, Tanner stage, sex, and BMI. In the Ala12 group, birth weight Z score was positively associated with FFM (p < 0.01), and this relationship remained significant after controlling for confounding variables (p < 0.05). Small body weight at birth may program lower FFM in adolescents carrying the Ala12 allele in the PPARgamma-2 gene.

Monitoring road surfaces by close proximity noise of the tire/road interaction

Applied acoustics is becoming an important field for civil infrastructure and environmental assessment, and road maintenance or rehabilitation strategies. In this research LA(2)IC has developed a GPS-based measurement techniques and apparatus on a test vehicle, for monitoring the acoustical properties of different road pavement surfaces with a reference tire. A field test on PA-12 Spanish porous pavement found in Ciudad Real is developed. The test procedure, a modification based upon the close-proximity method (CPX), relies on the use of three standard microphones situated very close to the tire/road contact patch. This procedure allows the simultaneous measurement of the sound emission synchronized to a GPS receiver, which permits tracking of the position of the sound emission. Geo-referenced sound spectra for every 10 m during individual passes of the test vehicle are analyzed to determine the tire/road noise emissions from tire/PA-12 pavement interaction. Noise levels of around 102 dB(A), with a variability of approximately 0.6 dB(A), are found at a reference vehicle speed of 85 kmh. The frequency spectrum analysis over the test section shows noticeable differences for frequencies above 1 kHz, where the tire/road noise generation mechanisms are dominated by air pumping.

Body fat distribution reference standards in Spanish adolescents: the AVENA Study

OBJECTIVE

To present body fat patterning reference standards to identify children with a predominant distribution of body fat in the abdominal or truncal region of the body.

DESIGN

Cross-sectional study in a representative sample of Spanish adolescents aged 13-18 years.

SUBJECTS

A total of 2160 adolescents with a complete set of anthropometric measurements (1109 males and 1051 females).

MEASUREMENTS

Weight, height, body mass index, skinfold thickness (biceps, triceps, subscapular, suprailiac, thigh, calf) and waist and hip circumferences.

RESULTS

In the majority of the age groups, subscapular/triceps skinfolds ratio, trunk-to-total skinfolds percent (TTS%)and waist circumference values were significantly higher in males than in females; hip circumference was higher in females than in males, except at 15.5 years. In males, age showed a significant effect for all the body fat distribution indices; however, in females, the effect was only significant for triceps skinfold, waist and hip circumferences and waist-to-hip ratio. Smoothed age- and sex-specific triceps skinfold, subscapular skinfold, subscapular/triceps skinfolds ratio, TTS%, waist circumference and hip circumference, waist-to-hip and waist-to-height ratio percentile values for male and female adolescents have been established.

CONCLUSION

These reference data for waist circumference and the other fat patterning indices, together with data from other countries, will help to establish international central obesity criteria for adolescents. The presented percentile values will give the possibility to estimate the proportion of adolescents with high or low regional adiposity amounts.

Cardiorespiratory fitness and sedentary activities are associated with adiposity in adolescents

OBJECTIVE

To determine whether physical activity, sedentary activities, and/or cardiorespiratory fitness are related to waist circumference in adolescents, as previously reported in adults.

RESEARCH METHODS AND PROCEDURES

The study subjects were a representative sample of Spanish adolescents (N = 2859; 1357 boys, 1502 girls; age, 13 to 18.5 years), all of whom were involved in the AVENA (Food and Assessment of the Nutritional Status of Adolescents) study. BMI, waist circumference, pubertal maturation status, and cardiorespiratory fitness were measured in all. Leisure-time physical activity, sedentary activities, active commuting to school, and socioeconomic status were assessed by self-reported questionnaires.

RESULTS

No relationship was found between leisure-time physical activity and BMI or waist circumference. In contrast, and in both boys and girls and after adjustment for confounding variables, cardiorespiratory fitness was found to be inversely associated with waist circumference and BMI, independent of sedentary activities or physical activity (p < or = 0.001). The maximum oxygen consumption explained 13% of the variance in waist circumference in boys and 16% in girls. Sedentary activities were independently and directly related to waist circumference in both boys and girls (p < or = 0.05) and to BMI in boys (p < or = 0.05). Sedentary activities explained 10% of the variance in waist circumference in boys and 18% in girls. The BMI-adjusted waist circumference was inversely correlated with cardiorespiratory fitness in overweight-obese boys (p < or = 0.05) and showed a trend toward significance in girls (p < or = 0.1).

DISCUSSION

Both moderate to high levels of cardiorespiratory fitness and sedentary activities, but not physical activity, are associated with lower abdominal adiposity, as measured by waist circumference.

Anthropometric Determinants of a Clustering of Lipid-Related Metabolic Risk Factors in Overweight and Non-Overweight Adolescents – Influence of Cardiorespiratory Fitness

BACKGROUND/AIMS

To explore in adolescents the associations between simple anthropometric variables with a continuously distributed summary score for lipid-related metabolic risk in both overweight and non-overweight adolescents, and to test whether these associations are modified by the level of cardiorespiratory fitness.

METHODS

Cardiorespiratory fitness, BMI, skinfold thicknesses, body circumferences, and a continuously distributed clustering of lipid- related metabolic risk (calculated from LDL and HDL cholesterol, triglycerides, and glucose) were measured in 524 adolescents (265 males, 259 females, 15.3 +/- 1.4 years) from the cross-sectional multicentric AVENA study. Participants were classified as overweight (including obesity) or non-overweight.

RESULTS

Most anthropometric parameters were univariately related to the continuous lipid-related metabolic risk. However, after multicollinear analysis and generalized linear modelling, suprailiac skinfold thickness in males (p < 0.001, explained variance 12.2%) and waist-to-height ratio in females (p < 0.001, explained variance 10.0%) were the best determinants of the continuous metabolic risk score, after adjustment for age, sexual maturation, and economic status. These associations were slightly weakened in overweight males (p = 0.034) and females (p = 0.087), and did not interact with cardiorespiratory fitness.

CONCLUSION

Our data emphasize the usefulness of suprailiac skinfold thickness in males and waist-to-height ratio in females as simple anthropometric measurements associated to an overall lipid-related metabolic risk, mainly in non-overweight adolescents and regardless their cardiorespiratory status.

Screening Performances of the International Obesity Task Force Body Mass Index Cut-Off Values in Adolescents

OBJECTIVE

To try to improve the International Obesity Task Force (IOTF) BMI cut-off values, in terms of prediction of body fat percentage assessed by dual-energy X-ray absorptiometry (DXA), in adolescents.

METHODS

Cross-sectional survey of the adolescents from the city of Zaragoza (Spain). For this analysis we have included 286 adolescents (116 boys and 170 girls) aged 13.0-17.9 years. Body mass index (BMI) was calculated as body weight (kg), divided by height (m) squared. The percentage of body fat (BF%) was estimated by the use of DXA.

RESULTS

We have calculated, new BMI cut-off values (AVENA cut-offs) to predict BF%, for boys and girls in each age group. In male adolescents, sensitivity was higher with the IOTF cut-offs (0.71, 95th C.I.: 0.44, 0.90) than with the AVENA ones (0.53, 95th C.I.: 0.28, 0.77), and specificity was very similar with both cut-off values (0.86 and 0.88, respectively), the differences being not statistically significant. In girls, both sensitivities (0.75 and 0.79, respectively) and specificities (0.90 and 0.92, respectively) were very similar with both cut-off values, and the differences, not significant.

CONCLUSIONS

Optimization of the IOTF BMI cut-off values, in terms of BF%, seems not to be possible in adolescents. The IOTF criteria should be used only for overweight and obesity screening; however, in clinical settings, a more accurate measure of body fat should be recommended.