Craniometric variation among Brazilian and Scottish populations: a physical anthropology approach

The present investigation intended to compare the craniometric variations of two samples of different nationalities (Brazilian and Scottish). Materials and methods: The Brazilian sample consisted of 100 modern complete skulls, including 53 female skulls and 47 male skulls, and the Scottish sample consisted of 100 historical skulls (61 males, 39 females) and 36 mandibles (24 males, 12 females). The cranial measurement protocol was composed of 40 measurements, 11 bilateral and 29 unilateral, and the measurement protocol of the mandible was composed of 15 measurements, with six that were bilateral and nine that were unique. The comparative analysis of the metric variability between the two samples was performed using the means and medians analysis, the t-test, the Wilcoxon test, and the coefficient of variance, with a significance level of 5%. Results: The results showed that, among the 72 analysed variables, 44 measurements (61.11%) presented statistical differences between the samples. The Scottish skull tends to have a cranial length (GOL diff=5.53), breadth (XCB diff=3.78) and height (NPH diff=5.33) greater than the Brazilian skulls, and the Scottish mandibles tend to show a higher mandibular ramus height (MRH diff=9.25), a higher mandibular body height (HMB diff=6.37) and a larger bigonial breadth (BGB diff=5.29) than the Brazilians. The discriminant analysis of the 51 cranial measurements and 21 mandibular measurements showed a variation of the percentage of accuracy between 46.3- 83.8%. Conclusion: The metric analysis demonstrated that there is variability between the two samples studied (61.11%), but a concrete cause cannot be determined considering the multifactorial aspects of the variations of form and size

Autism Spectrum Disorder and mental health problems: patterns of difficulties and longitudinal trajectories in a population-based twin sample

There is increasing concern regarding additional psychiatric problems that co-occur with Autism Spectrum Disorder (ASD), as reflected in recent changes to diagnostic schemes. However, there remains little research with population-based samples across childhood. We report on additional problems, as measured by the Strengths and Difficulties Questionnaire, in a population-based sample of 135 twins with ASD, 55 non-ASD co-twins, and 144 comparison twins low in ASD traits. Frequencies, associated demographic factors, and changes in mental health difficulties from age 4 to 13 years are presented. Our data confirm the high rates of additional difficulties reported in previous studies, and suggest that the profile, associated risk factors and longitudinal course of additional difficulties in ASD may differ from those in typically-developing populations

The signature of competition in ecomorphological traits across the avian radiation

Competition for shared resources represents a fundamental driver of biological diversity. However, the tempo and mode of phenotypic evolution in deep-time has been predominantly investigated using trait evolutionary models which assume that lineages evolve independently from each other. Consequently, the role of species interactions in driving macroevolutionary dynamics remains poorly understood. Here, we quantify the prevalence for signatures of competition between related species in the evolution of ecomorphological traits across the bird radiation. We find that mechanistic trait models accounting for the effect of species interactions on phenotypic divergence provide the best fit for the data on at least one trait axis in 27 out of 59 clades ranging between 21 and 195 species. Where it occurs, the signature of competition generally coincides with positive species diversity-dependence, driven by the accumulation of lineages with similar ecologies, and we find scarce evidence for trait-dependent or negative diversity-dependent phenotypic evolution. Overall, our results suggest that the footprint of interspecific competition is often eroded in long-term patterns of phenotypic diversification, and that other selection pressures may predominantly shape ecomorphological diversity among extant species at macroevolutionary scales

Discriminant analysis of mandibular measurements for the estimation of sex in a modern Brazilian sample.

The present study aimed to evaluate the accuracy of mandibular measurements for sex determination in a Brazilian population. The sample was composed of 100 mandibles, of which 53 were female and 47 were male, and the average age was 57.03 years. The mandible measurement protocol was composed of 15 measurements, of which six were bilateral and nine were unique. Mandibles were directly measured using a digital caliper and a protractor. The descriptive analysis of the present study revealed higher mean values for male mandibles compared to those for female mandibles with the exception of the left mandibular angle. Among the 21 measures analyzed in this group, 15 were statistically significant (p < 0.05). Univariate discriminant analyses produced a mean percentage of correct predictions that varied between 49 and 79%. The association of variables increased the percentage of correct prediction of sex to vary from 76 to 86%. The receiver operator characteristic (ROC) curve analysis indicated that the best variable for estimating sex was bigonial breadth (BGB; area under the ROC curve (AUC) = 0.764) followed by the right maximum ramus height (MRHr; AUC = 0.763). A reference table for estimating sex in a Brazilian population using mandible measurements was developed based on the ROC curve analysis. Mandibular measures provide a simple and reliable method for sex discrimination in Brazilian adults due to the sexual dimorphism revealed by analysis of the metric variables and the satisfactory results demonstrated by discriminant formulas, ROC curve analysis, and the reference table

TEASING: a fast and accurate approximation for the low multipole likelihood of the Cosmic Microwave Background temperature

We explore the low-l likelihood of the angular spectrum C(l) of masked CMB temperature maps using an adaptive importance sampler. We find that, in spite of a partial sky coverage, the likelihood distribution of each C(l) closely follows an inverse gamma distribution. Our exploration is accurate enough to measure the inverse gamma parameters along with the correlation between multipoles. Those quantities are used to build an approximation of the joint posterior distribution of the low-l likelihood. The accuracy of the proposed approximation is established using both statistical criteria and a mock cosmological parameter fit. When applied to the WMAP5 data set, this approximation yields cosmological parameter estimates at the same level of accuracy as the best current techniques but with very significant speed gains.Comment: 10 pages, 10 figures, submitted to MNRA

Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses

The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined

A Thousand Contradictory Ways: Addiction, Neuroscience, and Expert Autobiography

Neuroscientific accounts of addiction are increasingly influential in health and medical circles. At the same time a diverse, if equally scientifically focused, opposition to addiction neuroscience is emerging. In this struggle over the merits of addiction neuroscience are elements of a uniquely 21st-century public engagement with science. No longer trusted by the public as the unerring source of objective knowledge about the world, science is, at least in some contexts, increasingly treated as just one voice among many. Observing the difficulties this loss of faith in science poses for effective action on pressing issues such as climate change, philosopher Bruno Latour develops a different (ecological) approach to scientific knowledge, one that for the first time allows scientists (and other “moderns”) to understand it for what it really is and locate it “diplomatically” alongside other modes of knowing. In this article, I ask whether a similar innovation is needed to allow more effective understanding of addiction. I explore this question by analyzing two recent, widely discussed, popular books (Marc Lewis’s Memoirs of an Addicted Brain: A Neuroscientist Examines His Former Life on Drugs, 2011 and Carl Hart’s High Price: A Neuroscientist’s Journey of Self-discovery that Challenges Everything You Think You Know About Drugs and Society, 2013) as well as reviews of these books. Written by neuroscientists, and drawing heavily on personal memoir to illustrate and ratify their competing views on drugs and addiction, both books crystallize contemporary dilemmas about science, empiricism, and the nature of evidence and truth. How are we to understand their mix of “scientific fact” and individual self-observation, what does this mix suggest about scientific knowledge, and what are its implications for dominant notions of “evidence-based” drug policy and treatment? I argue that these books both trouble and reinforce our taken-for-granted distinctions between science and personal stories, between objectivity and subjectivity, and note the lost opportunities the books represent for a more searching and productive (Latour might say “ecological”) engagement with science