Estimacion de sexo y edad a nivel esqueletico: aplicacion forense y antropologica

[ES] La estimación del sexo y la edad son esenciales para la identificación individual de restos humanos y para el conocimiento e interpretación de la variabilidad biológica del pasado. El objetivo de este trabajo es la elaboración de un protocolo metodológico de análisis morfológico y morfométrico, para la estimación del sexo en adultos y de la edad en subadultos y adultos. Las principales metodologías incluidas en este trabajo pueden emplearse en restos esqueléticos de procedencia europea. Se realizó una revisión bibliográfica en revistas de ámbito forense y antropológico a fin de reunir un conjunto de metodologías aplicables tanto a esqueletos completos como parciales. Finalmente, en la elección de los métodos incluidos en este protocolo se tuvieron en cuenta dos criterios: la bondad de ajuste y el grado de complejidad del método.

Difração de raios X por policristais: uma ferramenta para caracterização e determinação estrutural do protótipo a fármaco LASSBio-1755

Novos protótipos de fármacos estão constantemente a ser sintetizados e muitas estruturas cristalinas de outros ainda são desconhecidas. Tão importante quanto o planejamento e síntese de novos fármacos é a sua caracterização estrutural, uma vez que a sua estrutura (conformação) pode estar diretamente relacionada com a ação terapêutica. O uso da difração de raios X tem sido muito importante na determinação estrutural dos novos compostos sintetizados. Neste trabalho foi feita a determinação da estrutura de LASSBio-1755 com os dados de difração de raios X por policristais. Este composto foi sintetizado no Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio) da Universidade Federal do Rio de Janeiro. O composto LASSBio-1755 pertence a uma nova série de compostos cicloalquil-N-acilidrazônicos planejados para o desenvolvimento de protótipos com atividades antinociceptiva e anti-inflamatórios. Este composto cristalizou-se num sistema triclínico com grupo espacial (P ), com parâmetros de cela unitária a = 4,86647(9) Å, b = 9,3108(2) Å, c = 11,3402(2) Å, α = 106,649(1), β = 101,958(1), γ = 82,629(2) e V = 480,30(2) Å3. A estrutura cristalina de LASSBio-1755 consiste em duas fórmulas unitárias por cela unitária (Z = 2), acomodando uma molécula na unidade assimétrica (Z' = 1). O Método de Rietveld foi utilizado para refinar a estrutura cristalina e o indicador de qualidade do ajuste, bem como os fatores R foram, respectivamente: χ2 = 1,131, RBragg = 0,856%, Rwp =4,174% e o Rexp= 3,692%. As técnicas de calorimetria exploratória diferencial, termogravimetria e espectroscopia no infravermelho por transformada de Fourier também foram utilizadas para análise do composto LASSBio-1755 e os seus resultados corroboraram com os obtidos através da técnica de difração de raios X por policristais.

Modeling red sea urchin (Strongylocentrotus franciscanus) growth using six growth functions

The growth of red sea urchins (Strongylocentrotus franciscanus) was modeled by using tag-recapture data from northern California. Red sea urchins (n=211) ranging in test diameter from 7 to 131 mm were examined for changes in size over one year. We used the function Jt+1 = Jt + f(Jt) to model growth, in which Jt is the jaw size (mm) at tagging, and Jt+1 is the jaw size one year later. The function f(Jt), represents one of six deterministic models: logistic dose response, Gaussian, Tanaka, Ricker, Richards, and von Bertalanffy with 3, 3, 3, 2, 3, and 2 minimization parameters, respectively. We found that three measures of goodness of fi t ranked the models similarly, in the order given. The results from these six models indicate that red sea urchins are slow growing animals (mean of 7.2 ±1.3 years to enter the fishery). We show that poor model selection or data from a limited range of urchin sizes (or both) produces erroneous growth parameter estimates and years-to-fishery estimates. Individual variation in growth dominated spatial variation at shallow and deep sites (F=0.246, n=199, P=0.62). We summarize the six models using a composite growth curve of jaw size, J, as a function of time, t: J = A(B – e–Ct) + Dt, in which each model is distinguished by the constants A, B, C, and D. We suggest that this composite model has the flexibility of the other six models and could be broadly applied. Given the robustness of our results regarding the number of years to enter the fishery, this information could be incorporated into future fishery management plans for red sea urchins in northern California.

Phone-level pronunciation scoring and assessment for interactive language learning

This paper investigates a method of automatic pronunciation scoring for use in computer-assisted language learning (CALL) systems. The method utilizes a likelihood-based `Goodness of Pronunciation' (GOP) measure which is extended to include individual thresholds for each phone based on both averaged native confidence scores and on rejection statistics provided by human judges. Further improvements are obtained by incorporating models of the subject's native language and by augmenting the recognition networks to include expected pronunciation errors. The various GOP measures are assessed using a specially recorded database of non-native speakers which has been annotated to mark phone-level pronunciation errors. Since pronunciation assessment is highly subjective, a set of four performance measures has been designed, each of them measuring different aspects of how well computer-derived phone-level scores agree with human scores. These performance measures are used to cross-validate the reference annotations and to assess the basic GOP algorithm and its refinements. The experimental results suggest that a likelihood-based pronunciation scoring metric can achieve usable performance, especially after applying the various enhancements.

心理旋转中的整体优先效应及其机制

In the history of psychology research, more attention had been focused on the relation between local processing and global processing. For the global information and the local information, which is processed earlier? And which is processed faster? Precedence of the global over the local level in visual perception has been well established by Navon with compound stimuli, and Navon’s original study gave rise to many publications, including replications, generalization to other kinds of stimuli (nonverbal material, digits), populations (infants, children, brain-damaged subjects), and tasks (lateral visual hemifield presentation, copy drawing, memory recognition, and recall), and triggered some debate about the conditions in which global precedence is and is not observed (number, size, sparsity, and goodness of the stimuli, exposure duration, etc.). However, whether there is a global advantage or precedence in other cognitive processes was less tested. Most researches had suggested that there was a functional equivalency between visual perception and visual image processing. However, it’s still unknown whether there will be a global advantage on mental rotation. In the present study, we combined the mental rotation task with the compound stimuli to explore whether the global or local advantage also existed at the mental imagery transformation stages. In two pilot studies, the perceptual global precedence was found to be present in a normal/mirror-image judgment task when the stimuli exposure time was short; while the stimuli exposure time was prolonged (stimuli kept available till subjects’ response) the perceptual global precedence was showed to be eliminated. In all of the subsequent experiments, stimili would be presented till subjects’ response. Then mental rotation was added in normal/mirror-image judgment (some of the stimuli were rotated to certain angles from upright) in normal experiments, experiment 1 and 2 observed a global advantage on mental rotation both with a focused-attention design (Experiment 1) and divided-attention design (Experiment 2). Subjects’ reaction times were increased with rotation angles, and the accuracy was decreased with rotation angles, suggesting that subject need a mental rotation to make a normal/mirror judgment. The most important results were that subjects’ response to global rotation was faster than that to local rotation. The analysis of slope of rotation further indicated that, to some extend, the speed of global rotation was faster than that of local rotation. These results suggest a global advantage on mental rotation. Experiment 3 took advantage of the high temporal resolution of event-related potentials to explore the temporal pattern of global advantage on mental rotation. Event-related potential results indicated the parietal P300 amplitude was inversely related to the character orientation, and the local rotation task delayed the onset of the mental-rotation-related negativity at parietal electrodes. None clear effect was found for occipital N150. All these results suggested that the global rotation was not only processed faster than local rotation, but also occurred earlier than local rotation. Experiments 4 and 5 took the effect size of global advantage as the main dependent variable, and visual angle and exposure duration of the stimuli as independent variables, to examine the relationship between perceptual global precedence and global advantage on mental rotation. Results indicated that visual angle and exposure duration did not influence the effect size of global advantage on mental rotation. The global advantage on mental rotation and the perceptual global advantage seemed to be independent but their effects could be accumulated at some condition. These findings not only contribute to revealing a new processing property of mental rotation, but also deepen our understanding of the problem of global/local processing and shed light on the debate on locus of global precedence.

(Semi-)Predictive Discretization During Model Selection

In this paper, we present an approach to discretizing multivariate continuous data while learning the structure of a graphical model. We derive the joint scoring function from the principle of predictive accuracy, which inherently ensures the optimal trade-off between goodness of fit and model complexity (including the number of discretization levels). Using the so-called finest grid implied by the data, our scoring function depends only on the number of data points in the various discretization levels. Not only can it be computed efficiently, but it is also independent of the metric used in the continuous space. Our experiments with gene expression data show that discretization plays a crucial role regarding the resulting network structure.

Shape from Contour

The problem of using image contours to infer the shapes and orientations of surfaces is treated as a problem of statistical estimation. The basis for solving this problem lies in an understanding of the geometry of contour formation, coupled with simple statistical models of the contour generating process. This approach is first applied to the special case of surfaces known to be planar. The distortion of contour shape imposed by projection is treated as a signal to be estimated, and variations of non-projective origin are treated as noise. The resulting method is then extended to the estimation of curved surfaces, and applied successfully to natural images. Next, the geometric treatment is further extended by relating countour curvature to surface curvature, using cast shadows as a model for contour generation. This geometric relation, combined with a statistical model, provides a measure of goodness-of-fit between a surface and an image contour. The goodness-of-fit measure is applied to the problem of establishing registration between an image and a surface model. Finally, the statistical estimation strategy is experimentally compared to human perception of orientation: human observers' judgements of tilt correspond closely to the estimates produced by the planar strategy.

The performance of models relating species geographical distributions to climate is independent of trophic level

Brian Huntley, Rhys E. Green, Yvonne C. Collingham, Jane K. Hill, Stephen G. Willis , Patrick J. Bartlein, Wolfgang Cramer, Ward J. M. Hagemeijer and Christopher J. Thomas (2004). The performance of models relating species geographical distributions to climate is independent of trophic level. Ecology Letters, 7(5), 417-426. Sponsorship: NERC (awards: GR9/3016, GR9/04270, GR3/12542, NER/F/S/2000/00166) / RSPB RAE2008

Automatic 3D Registration of Lung Surfaces in Computed Tomography Scans

We developed an automated system that registers chest CT scans temporally. Our registration method matches corresponding anatomical landmarks to obtain initial registration parameters. The initial point-to-point registration is then generalized to an iterative surface-to-surface registration method. Our "goodness-of-fit" measure is evaluated at each step in the iterative scheme until the registration performance is sufficient. We applied our method to register the 3D lung surfaces of 11 pairs of chest CT scans and report promising registration performance.

Bivariate distribution modeling with tree diameter and height data

The Logit-Logistic (LL), Johnson's SB, and the Beta (GBD) are flexible four-parameter probability distribution models in terms of the (skewness-kurtosis) region covered, and each has been used for modeling tree diameter distributions in forest stands. This article compares bivariate forms of these models in terms of their adequacy in representing empirical diameter-height distributions from 102 sample plots. Four bivariate models are compared: SBB, the natural, well-known, and much-used bivariate generalization of SB; the bivariate distributions with LL, SB, and Beta as marginals, constructed using Plackett's method (LL-2P, etc.). All models are fitted using maximum likelihood, and their goodness-of-fits are compared using minus log-likelihood (equivalent to Akaike's Information Criterion, the AIC). The performance ranking in this case study was SBB, LL-2P, GBD-2P, and SB-2P

Low temperature crystal structures of two rhodanine derivatives, 3-amino rhodanine and 3-methyl rhodanine: geometry of the rhodanine ring

Rhodanines (2-thio-4-oxothiazolidines) are synthetic small molecular weight organic molecules with diverse applications in biochemistry, medicinal chemistry, photochemistry, coordination chemistry and industry. The X-ray crystal structure determination of two rhodanine derivatives, namely (I), 3-aminorhodanine [3-amino-2-thio-4-oxothiazolidine], C3H4N2OS2, and (II) 3-methylrhodanine [3-methyl-2-thio-4-oxothiazolidine], C4H5NOS2, have been conducted at 100 K. I crystallizes in the monoclinic space group P2(1)/n with unit cell parameters a = 9.662(2), b = 9.234(2), c = 13.384(2) angstrom, beta = 105.425(3)degrees, V = 1151.1(3) angstrom(3), Z = 8 (2 independent molecules per asymmetric unit), density (calculated) = 1.710 mg/m(3), absorption coefficient = 0.815 mm(-1). II crystallizes in the orthorhombic space group Iba2 with unit cell a = 20.117(4), b = 23.449(5), c = 7.852(2) angstrom, V = 3703.9(12) angstrom(3), Z = 24 (three independent molecules per asymmetric unit), density (calculated) = 1.584 mg/m(3), absorption coefficient 0.755 mm(-1). For I in the final refinement cycle the data/restraints/parameter ratios were 2639/0/161, goodness-of-fit on F-2 = 0.934, final R indices [I > 2sigma(I)] were R1 = 0.0299, wR2 = 0.0545 and R indices (all data) R1 = 0.0399, wR2 = 0.0568. The largest difference peak and hole were 0.402 and -0.259 e angstrom(-3). For II in the final refinement cycle the data/restraints/parameter ratios were 3372/1/221, goodness-of-fit on F(2) = 0.950, final R indices [I > 2sigma(I)] were R1 = 0.0407, wR2 = 0.1048 and R indices (all data) R1 = 0.0450, wR2 = 0.1088. The absolute structure parameter = 0.19(9) and largest difference peak and hole 0.934 and -0.301 e angstrom(-3). Details of the geometry of the five molecules (two for I and three for II) and the crystal structures are fully discussed. Corresponding features of the molecular geometry are highly consistent and firmly establish the geometry of the rhodanine

Low temperature crystal structure of N-Acetyl-L-Glutamic acid: comparison with the DFT calculated structure

N-acetyl-L-glutamic acid, crystallizes in the orthorhombic space group P2(1)2(1)2(1) with unit cell parameters a = 4.747(3), b = 12.852(7), c = 13.906(7) Å, V = 848.5(8) Å3, Z = 4, density (calculated) = 1.481 mg/m3, linear absorption coefficient 0.127 mm−1. The crystal structure determination was carried out with MoKalpha X-ray data measured with liquid nitrogen cooling at 100(2) K temperature. In the final refinement cycle the data/restraints/parameter ratios were 1,691/0/131; goodness-of-fit on F(2) = 1.122. Final R indices for [I > 2sigma(I)] were R1 = 0.0430, wR2 = 0.0878 and R indices (all data) R1 = 0.0473, wR2 = 0.0894. The largest electron density difference peak and hole were 0.207 and −0.154 eÅ(−3). Details of the molecular geometry are discussed and compared with a model DFT structure calculated using Gaussian 98.

Modelling the effects of climate change on the distribution and production of marine fishes: accounting for trophic interactions in a dynamic bioclimate envelope model

Climate change has already altered the distribution of marine fishes. Future predictions of fish distributions and catches based on bioclimate envelope models are available, but to date they have not considered interspecific interactions. We address this by combining the species-based Dynamic Bioclimate Envelope Model (DBEM) with a size-based trophic model. The new approach provides spatially and temporally resolved predictions of changes in species' size, abundance and catch potential that account for the effects of ecological interactions. Predicted latitudinal shifts are, on average, reduced by 20% when species interactions are incorporated, compared to DBEM predictions, with pelagic species showing the greatest reductions. Goodness-of-fit of biomass data from fish stock assessments in the North Atlantic between 1991 and 2003 is improved slightly by including species interactions. The differences between predictions from the two models may be relatively modest because, at the North Atlantic basin scale, (i) predators and competitors may respond to climate change together; (ii) existing parameterization of the DBEM might implicitly incorporate trophic interactions; and/or (iii) trophic interactions might not be the main driver of responses to climate. Future analyses using ecologically explicit models and data will improve understanding of the effects of inter-specific interactions on responses to climate change, and better inform managers about plausible ecological and fishery consequences of a changing environment.

Evaluating machine-learning techniques for recruitment forecasting of seven North East Atlantic fish species

The effect of different factors (spawning biomass, environmental conditions) on recruitment is a subject of great importance in the management of fisheries, recovery plans and scenario exploration. In this study, recently proposed supervised classification techniques, tested by the machine-learning community, are applied to forecast the recruitment of seven fish species of North East Atlantic (anchovy, sardine, mackerel, horse mackerel, hake, blue whiting and albacore), using spawning, environmental and climatic data. In addition, the use of the probabilistic flexible naive Bayes classifier (FNBC) is proposed as modelling approach in order to reduce uncertainty for fisheries management purposes. Those improvements aim is to improve probability estimations of each possible outcome (low, medium and high recruitment) based in kernel density estimation, which is crucial for informed management decision making with high uncertainty. Finally, a comparison between goodness-of-fit and generalization power is provided, in order to assess the reliability of the final forecasting models. It is found that in most cases the proposed methodology provides useful information for management whereas the case of horse mackerel is an example of the limitations of the approach. The proposed improvements allow for a better probabilistic estimation of the different scenarios, i.e. to reduce the uncertainty in the provided forecasts.

Integration of shading and texture cues: testing the linear model

One of the first attempts to develop a formal model of depth cue integration is to be found in Maloney and Landy's (1989) "human depth combination rule". They advocate that the combination of depth cues by the visual sysetem is best described by a weighted linear model. The present experiments tested whether the linear combination rule applies to the integration of texture and shading. As would be predicted by a linear combination rule, the weight assigned to the shading cue did vary as a function of its curvature value. However, the weight assigned to the texture cue varied systematically as a function of the curvature value of both cues. Here we descrive a non-linear model which provides a better fit to the data. Redescribing the stimuli in terms of depth rather than curvature reduced the goodness of fit for all models tested. These results support the hypothesis that the locus of cue integration is a curvature map, rather than a depth map. We conclude that the linear comination rule does not generalize to the integration of shading and texture, and that for these cues it is likely that integration occurs after the recovery of surface curvature.