Role of de Vries in the rediscovery of Mendel's paper. II. Did de Vries really understand Mendel's paper?

In this paper, we discuss briefly three of the several lines of evidence that we believe demonstrate de Vries's lack of understanding of Mendel's paper. In our view, at least part of de Vries's failure of understanding derives from the fact that he appears to have viewed Mendel's paper as being mainly about the inheritance of characters that was his own interest. Therefore, he looked at it to see whether Mendel had found any laws of inheritance. Mendel had done his research for another purpose, to find the laws describing the formation of hybrids and the development of their offspring. Thus, de Vries started his examination of Mendel's paper with a very fundamental misunderstanding of what it was about.     

What about the ducks? An alternative vaccination strategy.

Like most emerging disease threats, avian influenza is a zoonotic disease maintained in nature by wildlife. In this case, the reservoir of infection is migratory waterfowl, primarily ducks. Rather than trying to vaccinate most of the world's human population in response to the threat of an avian influenza pandemic, it might be more prudent to vaccinate key reservoir wildlife species from which pandemic strains evolve. This strategy would require a much more intensive research effort to understand the evolution of avian influenza viruses in nature, but it would be far less costly than any of the alternatives. Research priorities for emerging zoonoses, such as new strains of avian influenza viruses, should be re-evaluated with an emphasis on ways to intervene at their source, the natural reservoir hosts from which they originate, rather than focusing up on human-based interventions, which are too often too late.     

What can whole genome expression data tell us about the ecology and evolution of personality?

Consistent individual differences in behaviour, aka personality, pose several evolutionary questions. For example, it is difficult to explain within-individual consistency in behaviour because behavioural plasticity is often advantageous. In addition, selection erodes heritable behavioural variation that is related to fitness, therefore we wish to know the mechanisms that can maintain between-individual variation in behaviour. In this paper, we argue that whole genome expression data can reveal new insights into the proximate mechanisms underlying personality, as well as its evolutionary consequences. After introducing the basics of whole genome expression analysis, we show how whole genome expression data can be used to understand whether behaviours in different contexts are affected by the same molecular mechanisms. We suggest strategies for using the power of genomics to understand what maintains behavioural variation, to study the evolution of behavioural correlations and to compare personality traits across diverse organisms.     

Vanadium and diabetes. What about vanadium toxicity?: A reply

Molecular and Cellular Biochemistry -     

What are we talking about when we talk about education and Chagas? A systematic review of the issue

More than 110 years has passed since the first publications on Chagas disease, and it still urges the necessity of understanding it as a complex socioenvironmental issue in which components of diverse nature converge and interact beyond the biomedical and epidemiological aspects. The current scenarios of the issue, both rural and Latin American as urban and global, demand that the education on Chagas disease include all possible contexts: where there are insect vectors and where there are not; inside and outside Latin America; in rural, periurban, and urban areas; in formal and non-formal educational environments. We consider essential the requirement of both an integral approach that overcomes the biomedical aspect to include the multidimensionality of the issue and a dialogical educational perspective that allows individuals and communities to analyze, decide, and lead contextualized prevention and promotion actions regarding their health. In this study, we surveyed, described, and critically analyzed studies approaching the link education-Chagas disease in scientific publications from the last 15 years. We aimed at contributing methodological-theoretical elements to (re)think the development of educational research and experiences that truly help facing this issue. From the electronic search of scientific literature in 6 databases, we found 426 articles, out of which we selected 25. We incorporated 10 articles from other sources to this initial corpus and performed both qualitative and quantitative analyses over the total number [35] to characterize the studied works in general, focusing on the conceptions on the Chagas disease issue and the underlying health education approaches.     

What is mtDNA good for in the study of primate evolution?

Recombinant DNA methods have made accessible the nuclear and organelle genomes of a vast array of plant and animal species.^1–3 Although evolutionary biologists and anthropologists have begun to exploit the full range of these methods, a disproportionate share of this research has centered on the mitochondrial genome (mtDNA). Because of its small size, conserved organization, mode of inheritance, and combination of rapidly and slowly evolving regions, mtDNA (Fig. 1) has appeared in many ways to be the ideal molecule for evolutionary studies of primates.^4,5 However, recent research on higher primates raises serious concerns about the utility of this molecule for evolutionary analysis in the absence of parallel data from the nuclear genome.^6–8 These studies suggest that we need to rethink our research strategies and define more clearly what mtDNA can be used for in the study of primate evolution.     

Is the ratio of inhaled corticosteroid to bronchodilator a good indicator of the quality of asthma prescribing? Cross sectional study linking prescribing data to data on admissions.

OBJECTIVE: To investigate the ratio of inhaled corticosteroid to bronchodilator as a measure of the quality of asthma prescribing by general practitioners. DESIGN: Ecological cross sectional study linking general practitioner asthma prescribing with hospital admission data and a measure of deprivation. SUBJECTS: 11 family health services authorities in the West Midlands region and 99 general practices in North Staffordshire. MAIN OUTCOME MEASURES: Hospital admission rates for asthma; the ratio of inhaled corticosteroid to bronchodilator; and Townsend deprivation scores. RESULTS: No overall significant correlation was found between admission rates for asthma and corticosteroid:bronchodilator ratios for family health services authorities (Spearman''s rs = -0.109, P = 0.750) or general practices (rs = -0.084, P = 0.407). In deprived family health services authority areas and general practices an inverse non-significant correlation existed between admission rates for asthma and corticosteroid:bronchodilator ratios (rs = -0.300, P = 0.624; rs = -0.218, P = 0.136). In contrast, in more affluent areas and general practices a positive non-significant correlation existed between admission rates and corticosteroid:bronchodilator ratios (rs = 0.371, P = 0.468; rs = 0.038, P = 0.792). CONCLUSION: Although the corticosteroid:bronchodilator ratio may be a valid indicator of the quality of prescribing for individual patients with asthma, caution should be applied in interpreting aggregated ratios. Differences in the severity of asthma or the prevalence of chronic obstructive pulmonary disease may explain inconsistent associations between admission rates for asthma and corticosteroid:bronchodilator ratios in family health services authorities and general practices with different deprivation scores.     

What do we know about the mechanisms of aromatase inhibitor resistance?

Clinical trials have demonstrated the importance of aromatase inhibitor (AI) therapy in the effective treatment of hormone-dependent breast cancers. Yet, as with all prolonged drug therapy, resistance to aromatase inhibitors does develop. To date, the precise mechanism responsible for resistance to aromatase inhibitors is not completely understood. In this paper, several mechanisms of de novo/intrinsic resistance and acquired resistance to AIs are discussed. These mechanisms are hypothesized based on important findings from a number of laboratories.

To better understand this question, our lab has generated, in vitro, breast cancer cell lines that are resistant to aromatase inhibitors. Resistant cell lines were generated over a prolonged period of time using the MCF-7aro (aromatase overexpressed) breast cancer line. These cell lines are resistant to the aromatase inhibitors letrozole, anastrozole and exemestane and the anti-estrogen tamoxifen, for comparison. Two types of resistant cell lines have been generated, those that grow in the presence of testosterone (T) which is needed for cell growth, and resistant lines that are cultured in the presence of inhibitor only (no T). In addition to functional characterization of aromatase and ER in these resistant cell lines, microarray analysis has been employed in order to determine differential gene expression within the aromatase inhibitor resistant cell lines versus tamoxifen, in order to better understand the mechanism responsible for AI resistance on a genome-wide scale. We anticipate that our studies will generate important information on the mechanisms of AI resistance. Such information can be valuable for the development of treatment strategies against AI-resistant breast cancers.     

What can the Samoan "Fa'afafine" teach us about the Western concept of gender identity disorder in childhood?

This article examines whether gender identity disorder in childhood (GIDC) constitutes a mental disorder as outlined by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV-TR). Data were collected in Samoa, a culture that is characterized by a high degree of social tolerance towards feminine males who are known locally as fa'afafine. The study location was chosen because, unlike Western locales, it afforded the opportunity to examine whether gender-atypical behavior, gender-atypical identity, and sex-atypical identity, in and of themselves, cause distress in sex/gender variant individuals, while simultaneously controlling for the confounding effects of extreme societal intolerance towards such individuals. Because of our focus on the DSM-IV-TR's diagnosis of GIDC, we were specifically interested in ascertaining whether adult fa'afafine recalled a strong and persistent cross-gender identification in childhood, a sense of inappropriateness in the male-typical gender role, a discomfort with their sex, or distress associated with any of the above. In addition, we sought to determine whether parental encouragement or discouragement of cross-gender behaviors influence feelings of distress in relation to the behaviors in question. Based on the cross-cultural information presented here, we conclude that the diagnostic category of GIDC should not occur in its current form in future editions of the DSM, as there is no compelling evidence that cross-gender behaviors or identities, in and of themselves, cause distress in the individual.     

What does the fruitless gene tell us about nature vs. nurture in the sex life of Drosophila?

The fruitless (fru) gene in Drosophila has been proposed to play a master regulator role in the formation of neural circuitries for male courtship behavior, which is typically considered to be an innate behavior composed of a fixed action pattern as generated by the central pattern generator. However, recent studies have shed light on experience-dependent changes and sensory-input-guided plasticity in courtship behavior. For example, enhanced male-male courtship, a fru mutant “hallmark,” disappears when fru-mutant males are raised in isolation. The fact that neural fru expression is induced by neural activities in the adult invites the supposition that Fru as a chromatin regulator mediates experience-dependent epigenetic modification, which underlies the neural and behavioral plasticity.     

A propos de l'article ‘The B-chromosomes of Locusta migratoria I. Detection of negative correlation between mean chiasma frequency and the rate of accumulation of the B's; a reanalysis of the available data about the transmission of these B-chromosomes’, par. J. Cabrero,E. Viseras et J. P. M. Camacho

Comment on the article ‘The B-chromosomes of Locusta migratoria I. Detection of negative correlation between mean chiasma frequency and the rate of accumulation of the B's; a reanalysis of the available data about the transmission of these B-chromosomes’ — Some critical remarks on the said article (published in Genetica 64: 155–164, 1984) are presented.