Indicators for the total number of melanocytic naevi : an adjunct for screening campaigns. Observational study on 292 patients.

BACKGROUND: The presence of multiple melanocytic naevi is a strong risk factor for melanoma. Use of the whole body naevus count to identify at-risk patients is impractical. OBJECTIVES: To (i) identify a valid anatomical predictor of total naevus count; (ii) determine the number of naevi that most accurately predict total naevus count above 25, 50 and 100; and (iii) evaluate determinants of multiple melanocytic naevi and atypical naevi. METHODS: Clinical data from 292 consecutive Spanish patients consulting for skin lesions requiring debriding were collected throughout 2009 and 2010. Correlations between site-specific and whole body naevus counts were analysed. Cut-offs to predict total naevus counts were determined using the area under the receiver operating characteristic curve. RESULTS: The studied population was young (median age 31 years, interquartile range 28-43). The naevus count on the right arm correlated best with the total nevus count (R(2) 0·80 for men, 0·86 for women). Presence of at least five naevi on the right arm was the strongest determinant of a total naevus count above 50 [odds ratio (OR) 34·4, 95% confidence interval (CI) 13·9-85·0] and of having at least one atypical naevus (OR 5·7, 95% CI 2·4-13·5). Cut-off values of 6, 8 and 11 naevi on the right arm best predicted total naevus count above 25, 50 and 100, respectively. CONCLUSIONS: Our results support the arm as a practical and reliable site to estimate the total naevus count when screening or phenotyping large populations. Threshold values for the number of naevi on the arm are proposed to help identify patients for melanoma screening.

Evaluating sampling strategies and logistic regression methods for modelling complex land cover changes

The role of land cover change as a significant component of global change has become increasingly recognized in recent decades. Large databases measuring land cover change, and the data which can potentially be used to explain the observed changes, are also becoming more commonly available. When developing statistical models to investigate observed changes, it is important to be aware that the chosen sampling strategy and modelling techniques can influence results. We present a comparison of three sampling strategies and two forms of grouped logistic regression models (multinomial and ordinal) in the investigation of patterns of successional change after agricultural land abandonment in Switzerland. Results indicated that both ordinal and nominal transitional change occurs in the landscape and that the use of different sampling regimes and modelling techniques as investigative tools yield different results. Synthesis and applications. Our multimodel inference identified successfully a set of consistently selected indicators of land cover change, which can be used to predict further change, including annual average temperature, the number of already overgrown neighbouring areas of land and distance to historically destructive avalanche sites. This allows for more reliable decision making and planning with respect to landscape management. Although both model approaches gave similar results, ordinal regression yielded more parsimonious models that identified the important predictors of land cover change more efficiently. Thus, this approach is favourable where land cover change pattern can be interpreted as an ordinal process. Otherwise, multinomial logistic regression is a viable alternative.

Computation of an integral basis of a quartic number field

"Vegeu el resum a l'inici del document del fitxer adjunt."

Establiment de bases científiques per al desenvolupament d'una estratègia integrada per avaluar toxicitat en reproducció

Report for the scientific sojourn at the National Institute for Public Health and the Environment (RIVM), Netherlands, from 2006 to 2008. This project aimed at creating scientific elements that could help deriving an integrated testing strategy for reproductive toxicity. Part of the project focused on the use of alternative tests for regulatory purposes. An in vitro-in vivo extrapolation method for embryotoxicity was proposed and evaluated. In vitro and in vivo dose descriptors were correlated; however, the scatter in the correlation was too large to allow an accurate estimation of an in vivo dose from an in vitro dose. The in vitro-in vivo extrapolation method together with toxicokinetic data was also applied to a category of substances (phthalates). Although based on a limited number of substances, the results suggested that in vitro-in vivo extrapolation for embryotoxicity is possible within a category of compounds if adequate toxicokinetic data is available. Because of the limitations that still remain in the use of alternative tests for reproductive toxicicity, other approaches to reduce animal testing were explored. Thus, a database of reproductive toxicity studies was created to retrospectively evaluate the comparative value of some studies or elements in a particular study. When compared to the subchronic toxicity study, the rat two-generation reproductive toxicity study had a considerable impact on the identification of hazard for reproductive toxicity, but not on the overall NOAEL. Among the two-generation studies included in our database, the second generation affected neither the overall NOAEL nor the critical effect. The rat and the rabbit developmental toxicity studies were, on average, similarly sensitive. However, for certain substances the developmental study in either one of the two species appeared to be more sensitive than in the other species.

Computation of an integral basis of quartic number field

"Vegeu el resum a l'inici del document del fitxer ajunt."

Rhinitis due to acrylates : case report

Background: Acrylates and methacrylates (salts and esters of acrylic and metacrylic acid respectively), are monomers commonly found in polymer plastics, resins and glues, and are widely used in many industry sectors. The first adverse health effects described were skin reactions and asthma. Exposure to acrylates, for instance when using multicomponent glues, is now a well known cause of occupational asthma. Methods: We report the case of a rhinitis - and possible asthma - to acrylates, in a 38-year-old woman, working in a nail beauty salon. She was currently treated for hypertension, and otherwise known for obesity and seasonal rhinoconjunctivitis, but did not have any respiratory problem. Two years after starting this activity, she progressively started to complain of anosmia, rhinitis, and intermittent dyspnea. Her job consisted in decorating nails with a mixture of a polymer powder and a liquid monomer, after removing the previous artificial nail with a small sander. We assessed exposure to acrylates at her working place, both as dust (from sanded nails) and volatile compound (from the mixture described above), and she was asked to measure her peak flow values twice a day for ten days, in order to detect a possible relationship between her occupational activities, the symptoms and the peak flow values. Results: Measures made during the visit of the patient's place of work showed that the existing aspiration system was efficient for eliminating the dust produced by nail sanding, but not for eliminating the volatile components. Thus, occupational exposure to acrylates was demonstrated. Moreover, the peak flow measures showed an average decrease of almost 10 percent when the patient was at work, compared to when she stayed home. We concluded that she actually suffered from professional rhinitis and, possibly, professional asthma (not certain because of the limited number of peak flow measures per day). Conclusion: Although exposure to acrylates is a well known cause of occupational asthma, it should be emphasized that the exact mechanisms of action remain unknown, despite the abundant literature about it. Some professions, which tend to be more frequent nowadays (such as working in a nail beauty salon), can expose the worker to particular risks. This highlights the need of always inquiring not only about the profession, but also the related activities, when facing a case of suspected asthma.

Comparative studies on the growth and reproductive performances of Rhodnius prolixus reared on different blood sources

Host blood source was found to affect both the development and the reproductive performance of Rhodnius prolixus. The insects were reared on citrated human, rabbit, chicken, sheep and horse blood sources, through a membrane feeder, during an entire life cycle, from eggs to adults. Development and reproduction in terms of the number of unfed insects, number of moulting, mortality intermoulting period, number of egg/female, conversion of blood into egg (mg meal/egg) and percentage of hatch as effective physiological parameters were investigated. Our results showed that human or rabbit blood meals were more nutritionally efficient than the other blood samples used because (i) the insects developed faster, presented low mortality and about 80% of them reached the adult stage; and (ii) females oviposited an average of at least 100% more eggs. The inefficiency of chicken and horse blood sources as diets for R. prolixus was manifested in (i) a decrease of the amount of ingested blood and (ii) only a reasonable nutritional quality. The inadequacy of sheep blood was observed by a mortality extremely high, poor moulting response and drastic reduction in egg production.

Estudos bionomicos de Cavernicola lenti Barrett & Arias, 1985 (Hemiptera, Reduviidae, Triatominae)

In the biological study, the development of the biological cycle of the insect under different feeding conditions was evaluated. The insects were fed on either mouse blood (c) or pigeon blood (p) using two types of rearing techniques (individual or group) at 28(graus) C and 90% relative humidity (which is equivalent to their natural environment). A fifth cycle studied, was fed on mouse blood reared on group, and mantained at laboratory environmental temperature. In the five cycles analyzed, it was found that groups on mouse blood at near natural conditions developed more rapidly (between 60 and 73 days) and had a lower rate of mortality (16.66%). The daily handling and changes in environment, of the individually reared insects, for observation of biological characteristics (no. and duration of bloodmeal, defecation and first fed of each stage) had a negative influence. None of the individuals fed on mouse or pigeon blood reached adult hood. It was found that the longevity and the fertility rate were significantly superior on couples maintained individually on mouse blood. These males had an average lifespan of 110,26 days and the females had an average lifespan of 104,46 days. The average number of eggs laid by each female was 21,26. Four couples kept in groups (five couples in each group) under the same condition, the longevity for males was 51,86 days and for females was 81,06 days. An average of 10,5 eggs were laid by each female. However, the percentage of fertile eggs was higher in couples kept in groups (72.15%) than in the individual couples (57.68%).

Improved temporal resolution for functional studies with reduced number of segments with three-dimensional echo planar imaging.

PURPOSE: To introduce a new k-space traversal strategy for segmented three-dimensional echo planar imaging (3D EPI) that encodes two partitions per radiofrequency excitation, effectively reducing the number excitations used to acquire a 3D EPI dataset by half. METHODS: The strategy was evaluated in the context of functional MRI applications for: image quality compared with segmented 3D EPI, temporal signal-to-noise ratio (tSNR) (the ability to detect resting state networks compared with multislice two-dimensional (2D) EPI and segmented 3D EPI, and temporal resolution (the ability to separate cardiac- and respiration-related fluctuations from the desired blood oxygen level-dependent signal of interest). RESULTS: Whole brain images with a nominal voxel size of 2 mm isotropic could be acquired with a temporal resolution under half a second using traditional parallel imaging acceleration up to 4× in the partition-encode direction and using novel data acquisition speed-up of 2× with a 32-channel coil. With 8× data acquisition speed-up in the partition-encode direction, 3D reduced excitations (RE)-EPI produced acceptable image quality without introduction of noticeable additional artifacts. Due to increased tSNR and better characterization of physiological fluctuations, the new strategy allowed detection of more resting state networks compared with multislice 2D-EPI and segmented 3D EPI. CONCLUSION: 3D RE-EPI resulted in significant increases in temporal resolution for whole brain acquisitions and in improved physiological noise characterization compared with 2D-EPI and segmented 3D EPI. Magn Reson Med 72:786-792, 2014. © 2013 Wiley Periodicals, Inc.

Genuine savings and future well-being in Germany, 1850-2000

Genuine Savings (GS), also known as ‘net adjusted savings’, is a composite indicator of the sustainability of economic development. Genuine Savings reflects year-on-year changes in the total wealth or capital of a country, including net investment in produced capita, investment in human capital, depletion of natural resources, and damage caused by pollution. A negative Genuine Savings rate suggests that the stock of national wealth is declining and that future utility must be less than current utility, indicating that economic development is non-sustainable (Hamilton and Clemens, 1999). We make use of data over a 150 year period to examine the relationship between Genuine Savings and a number of indicators of well-being over time, and compare the relative changes in human, produced, and components of natural capital over the period. Overall, we find that the magnitude of genuine savings is positively related to changes in future consumption, with some evidence of a cointegrating relationship. However, the relationships between genuine savings and infant mortality or average heights are less clear.

Penalizing Cartels: The Case for Basing Penalties on Price Overcharge

In this paper we set out the welfare economics based case for imposing cartel penalties on the cartel overcharge rather than on the more conventional bases of revenue or profits (illegal gains). To do this we undertake a systematic comparison of a penalty based on the cartel overcharge with three other penalty regimes: fixed penalties; penalties based on revenue, and penalties based on profits. Our analysis is the first to compare these regimes in terms of their impact on both (i) the prices charged by those cartels that do form; and (ii) the number of stable cartels that form (deterrence). We show that the class of penalties based on profits is identical to the class of fixed penalties in all welfare-relevant respects. For the other three types of penalty we show that, for those cartels that do form, penalties based on the overcharge produce lower prices than those based on profit) while penalties based on revenue produce the highest prices. Further, in conjunction with the above result, our analysis of cartel stability (and thus deterrence), shows that penalties based on the overcharge out-perform those based on profits, which in turn out-perform those based on revenue in terms of their impact on each of the following welfare criteria: (a) average overcharge; (b) average consumer surplus; (c) average total welfare.

Factors Affecting the Financial Success of Motion Pictures: What is the Role of Star Power?

In the mid-1940s, American film industry was on its way up to its golden era as studios started mass-producing iconic feature films. The escalating increase in popularity of Hollywood stars was actively suggested for its direct links to box office success by academics. Using data collected in 2007, this paper carries out an empirical investigation on how different factors, including star power, affect the revenue of ‘home-run’ movies in Hollywood. Due to the subjective nature of star power, two different approaches were used: (1) number of nominations and wins of Academy Awards by the key players, and (2) average lifetime gross revenue of films involving the key players preceding the sample year. It is found that number of Academy awards nominations and wins was not statistically significant in generating box office revenue, whereas star power based on the second approach was statistically significant. Other significant factors were critics’ reviews, screen coverage and top distributor, while number of Academy awards, MPAA-rating, seasonality, being a sequel and popular genre were not statistically significant.

Conjugacy of piecewise linear Lorenz map that expand on average

For piecewise linear Lorenz map that expand on average, we show that it admits a dichotomy: it is either periodic renormalizable or prime. As a result, such a map is conjugate to a ß-transformation.

Health care utilization among immigrants and native-born populations in 11 European countries. Results from the Survey of Health, Ageing and Retirement in Europe

Objective: This study examines health care utilization of immigrants relative to the native-born populations aged 50 years and older in eleven European countries. Methods. We analyzed data from the Survey of Health Aging and Retirement in Europe (SHARE) from 2004 for a sample of 27,444 individuals in 11 European countries. Negative Binomial regression was conducted to examine the difference in number of doctor visits, visits to General Practitioners (GPs), and hospital stays between immigrants and the native-born individuals. Results: We find evidence those immigrants above age 50 use health services on average more than the native-born populations with the same characteristics. Our models show immigrants have between 6% and 27% more expected visits to the doctor, GP or hospital stays when compared to native-born populations in a number of European countries. Discussion: Elderly immigrant populations might be using health services more intensively due to cultural reasons.

Low gene copy number shows that arbuscular mycorrhizal fungi inherit genetically different nuclei.

Arbuscular mycorrhizal fungi (AMF) are ancient asexually reproducing organisms that form symbioses with the majority of plant species, improving plant nutrition and promoting plant diversity. Little is known about the evolution or organization of the genomes of any eukaryotic symbiont or ancient asexual organism. Direct evidence shows that one AMF species is heterokaryotic; that is, containing populations of genetically different nuclei. It has been suggested, however, that the genetic variation passed from generation to generation in AMF is simply due to multiple chromosome sets (that is, high ploidy). Here we show that previously documented genetic variation in Pol-like sequences, which are passed from generation to generation, cannot be due to either high ploidy or repeated gene duplications. Our results provide the clearest evidence so far for substantial genetic differences among nuclei in AMF. We also show that even AMF with a very large nuclear DNA content are haploid. An underlying principle of evolutionary theory is that an individual passes on one or half of its genome to each of its progeny. The coexistence of a population of many genomes in AMF and their transfer to subsequent generations, therefore, has far-reaching consequences for understanding genome evolution.