The dental phenotype of hairless dogs with FOXI3 haploinsufficiency

Hairless dog breeds show a form of ectodermal dysplasia characterised by a lack of hair and abnormal tooth morphology. This has been attributed to a semi-dominant 7-base-pair duplication in the first exon of the forkhead box I3 gene (FOXI3) shared by all three breeds. Here, we identified this FOXI3 variant in a historical museum sample of pedigreed hairless dog skulls by using ancient DNA extraction and present the associated dental phenotype. Unlike in the coated wild type dogs, the hairless dogs were characterised in both the mandibular and maxillary dentition by a loss of the permanent canines, premolars and to some extent incisors. In addition, the deciduous fourth premolars and permanent first and second molars consistently lacked the distal and lingual cusps; this resulted in only a single enlarged cusp in the basin-like heel (talonid in lower molars, talon in upper molars). This molar phenotype is also found among several living and fossil carnivorans and the extinct order Creodonta in which it is associated with hypercarnivory. We therefore suggest that FOXI3 may generally be involved in dental (cusp) development within and across mammalian lineages including the hominids which are known to exhibit marked variability in the presence of lingual cusps

Pesquisa exploratória sobre avaliação ergonômica de interfaces de sites de Mobile Banking brasileiras para iphone

Orientadora: Profª Stephania PandovaniDissertação (mestrado) - Universidade Federal do Parana, Setor de Ciencias Humanas, Letras e Artes, Programa de Pós-Graduação em Design. Defesa: Curitiba, 10/06/2010Bibliografia: fls. 149-155Design gráfico e do produtoResumo: A chegada da terceira geração de celulares que, entre outras possibilidades, permite o acesso à internet móvel, está transformando o cotidiano de seus usuários. O acesso a serviços tornou-se ubíquo (a qualquer lugar/hora). No setor bancário o desafio é oferecer o mobile banking (mbanking). No Brasil, os principais bancos de varejo (Banco do Brasil, Bradesco, Itaú e Unibanco) oferecem diversas soluções óveis, entre as quais se destaca a otimização de sites para iPhone. O objetivo desta pesquisa, com base em IHC (interação humano-comupatdor), foi avaliar o design das interfaces de sites brasileiros de m-banking para iPhone com base em critérios ergonômicos e estágios cognitivos. Por se tratar de uma pesquisa exploratória foi definido um método que não envolveu usuários reais e que analisou as interfaces dos sites já implementadas. As seguintes técnicas foram utilizadas no método: a pesquisa bibliográfica, a avaliação heurística, a inspeção cognitiva e a lista de verificação. A avaliação heurística (elaborada com princípios ergonômicos citados na literatura), identificou os principaisproblemas ergonômicos no design de interfaces de sites brasileiros de m-banking para iPhone. Não foram identificados nenhum problema grave, apenas alguns problemas de gravidade mediana e muitos problemas com pouca gravidade. Por meio da inspeção cognitiva foram identificadas deficiências associadas a potenciais dificuldades na percepção, interpretação e operação dos componentes do design de interfaces de sites brasileiros de m-banking para iPhone. Os resultados da inspeção cognitiva indicaram que as interfaces dos sites dos bancos analisados falham com respeito a algum estágio do processo cognitivo do usuário. E, por fim, os resultados da lista de verificação dos bancos analisados (desenvolvida com base nas recomendações da Apple), indicaram que as interfaces dos sites de m-banking seguem parcialmente as diretrizes e as métricas propostas pela fabricante do iPhone. Uma vez identificados os problemas, foram feitas sugestões de melhoria para as interfaces dos sites pormeio de pareceres ergonômicos. Para gerar as sugestões, os problemas foram classificados de acordo com o modelo do processo de design de Garrett (2003). De acordo com este modelo, os problemas se concentraram no plano do esqueleto e no plano da estrutura. A partir dosdados obtidos, concluiu-se que as interfaces dos sites brasileiros de m-banking para iPhone apresentam problemas ergonômicos e de usabilidade.Abstract: The arrival of the third generation of the mobile technology that, beyond some capabilities, allows access to mobile internet is changing consumers/users daily lives. The access to this kind of service is biquitous, that is, anytime and anywhere. In the banking sector the challenge is to offer the mobile banking (m-banking). In Brazil, the main retail banks (Banco do Brasil, Bradesco, Itaú and Unibanco) offer some mobile solutions and among them the customized sites to iPhone are outstanding. The objective of this research, based upon HCI (human-computer interaction), was to evaluate the interfaces of Brazilian m-banking sites developed for iPhone based on ergonomic criteria and cognitive steps. This research can be classified as exploratory, so its method didn’t involve real users and tested sites interfaces already done. The following techniques were used in this method: literature research, heuristic evaluation, cognitive walkthrough and check-list. The heuristic evaluation (elaborated with ergonomic principles found in literature), has identified the main ergonomic problems in the interface design of Brazilian m-banking sites developed for iPhone. It hasn’t been identified any serious problem, only some medium seriousness problems and lots of problems with low gravity. The use of cognitive walkthrough made possible to identify deficiencies associated at potential difficulties in perception, understanding and performance of interface design components of Brazilian m-banking sites developed for iPhone. The results of the cognitive walkthrough have indicated that the analyzed banks sites interfaces fail at any point of the user cognitive process. And, at last, the heck–list results of the analyzed banks (developed based upon Apple recommendations), have indicated that the m-banking sites interfaces follow partially the recommendations and metrics proposed by iPhone manufacturer. Once the problems were identified, some suggestions to improve the websites interface design were proposed by ergonomic reports. To generate the suggestions, the problems were classified under the contextual model of the design process proposed by Garrett (2003). Accordingly to this model, the problems were concentrated in the skeleton plan and in the structure plan. From the obtained data, the onclusion was that the interfaces of Brazilian m-banking sites developed for iPhone present ergonomic and usability problems

Unexpected hard-object feeding in Western lowland gorillas

The cranial morphology of the earliest known hominins in the genus Australopithecus remains unclear. The oldest species in this genus (Australopithecus anamensis, specimens of which have been dated to 4.2–3.9 million years ago) is known primarily from jaws and teeth, whereas younger species (dated to 3.5–2.0 million years ago) are typically represented by multiple skulls. Here we describe a nearly complete hominin cranium from Woranso-Mille (Ethiopia) that we date to 3.8 million years ago. We assign this cranium to A. anamensis on the basis of the taxonomically and phylogenetically informative morphology of the canine, maxilla and temporal bone. This specimen thus provides the first glimpse of the entire craniofacial morphology of the earliest known members of the genus Australopithecus. We further demonstrate that A. anamensis and Australopithecus afarensis differ more than previously recognized and that these two species overlapped for at least 100,000 years—contradicting the widely accepted hypothesis of anagenesis

Effects of cropping, smoothing, triangle count, and mesh resolution on 6 dental topographic metrics

Dental topography is a widely used method for quantifying dental morphology and inferring dietary ecology in animals. Differences in methodology have brought into question the comparability of different studies. Using primate mandibular second molars, we investigated the effects of mesh preparation parameters smoothing, cropping, and triangle count/mesh resolution (herein, resolution) on six topographic variables (Dirichlet normal energy, DNE; orientation patch count rotated, OPCR; relief index, RFI; ambient occlusion, portion de ciel visible, PCV; enamel surface area, SA; tooth size) to determine the effects of smoothing, cropping, and triangle count/resolution on topographic values and the relationship between these values and diet. All topographic metrics are sensitive to smoothing, cropping method, and triangle count/resolution. In general, smoothing decreased DNE, OPCR, RFI, and SA,increased PCV, and had no predictable effect on tooth size. Relative to the basin cut off (BCO) cropping method, the entire enamel cap (EEC) method increased RFI, SA, and size, and had no predictable effect on DNE and OPCR. Smoothing and cropping affected DNE/ OPCR and surfaces with low triangle counts more than other metrics and surfaces with high triangle counts. There was a positive correlation between DNE/OPCR and triangle count/ resolution, and the rate of increase was weakly correlated to diet. PCV tended to converge or decrease with increases in triangle count/resolution, and RFI, SA, and size converged. Finally, there appears to be no optimal triangle count or resolution for predicting diet from this sample, and constant triangle count appeared to perform better than constant resolution for predicting diet

Dental topography and the diet of Homo naledi

Though late Middle Pleistocene in age, Homo naledi is characterized by a mosaic of Australopithecus-like (e.g., curved fingers, small brains) and Homo-like (e.g., elongated lower limbs) traits, which may suggest it occupied a unique ecological niche. Ecological reconstructions inform on niche occupation, and are particularly successful when using dental material. Tooth shape (via dental topography) and size were quantified for four groups of South African Plio-Pleistocene hominins (specimens of Australopithecus africanus, Paranthropus robustus, H. naledi, and Homo sp.) on relatively unworn M2s to investigate possible ecological differentiation in H. naledi relative to taxa with similar known geographical ranges. H. naledi has smaller, but higher-crowned and more wear resistant teeth than Australopithecus and Paranthropus. These results are found in both lightly and moderately worn teeth. There are no differences in tooth sharpness or complexity. Combined with the high level of dental chipping in H. naledi, this suggests that, relative to Australopithecus and Paranthropus, H. naledi consumed foods with similar fracture mechanics properties but more abrasive particles (e.g., dust, grit), which could be due to a dietary and/or environmental shift(s). The same factors that differentiate H. naledi from Australopithecus and Paranthropus may also differentiate it from Homo sp., which geologically predates it, in the same way. Compared to the great apes, all hominins have sharper teeth, indicating they consumed foods requiring higher shear forces during mastication. Despite some anatomical similarities, H. naledi likely occupied a distinct ecological niche from the South African hominins that predate it

Validity and sensitivity of a human cranial finite element model: Implications for comparative studies of biting performance

Finite element analysis (FEA) is a modelling technique increasingly used in anatomical studies investigating skeletal form and function. In the case of the cranium this approach has been applied to both living and fossil taxa to (for example) investigate how form relates to function or infer diet or behaviour. However, FE models of complex musculoskeletal structures always rely on simplified representations because it is impossible completely to image and represent every detail of skeletal morphology, variations in material properties and the complexities of loading at all spatial and temporal scales. The effects of necessary simplifications merit investigation. To this end, this study focuses on one aspect, model geometry, which is particularly pertinent to fossil material where taphonomic processes often destroy the finer details of anatomy or in models built from clinical CTs where the resolution is limited and anatomical details are lost. We manipulated the details of a finite element (FE) model of an adult human male cranium and examined the impact on model performance. First, using digital speckle interferometry, we directly measured strains from the infraorbital region and frontal process of the maxilla of the physical cranium under simplified loading conditions, simulating incisor biting. These measured strains were then compared with predicted values from FE models with simplified geometries that included modifications to model resolution, and how cancellous bone and the thin bones of the circum-nasal and maxillary regions were represented. Distributions of regions of relatively high and low principal strains and principal strain vector magnitudes and directions, predicted by the most detailed FE model, are generally similar to those achieved in vitro. Representing cancellous bone as solid cortical bone lowers strain magnitudes substantially but the mode of deformation of the FE model is relatively constant. In contrast, omitting thin plates of bone in the circum-nasal region affects both mode and magnitude of deformation. Our findings provide a useful frame of reference with regard to the effects of simplifications on the performance of FE models of the cranium and call for caution in the interpretation and comparison of FEA results

Dental wear patterns reveal dietary ecology and season of death in a historical chimpanzee population

Dental wear analyses have been widely used to interpret the dietary ecology in primates. However, it remains unclear to what extent a combination of wear analyses acting at distinct temporal scales can be beneficial in interpreting the tooth use of primates with a high variation in their intraspecific dietary ecology. Here, we combine macroscopic tooth wear (occlusal fingerprint analysis, long-term signals) with microscopic 3D surface textures (short-term signals) exploring the tooth use of a historical western chimpanzee population from northeastern Liberia with no detailed dietary records. We compare our results to previously published tooth wear and feeding data of the extant and continually monitored chimpanzees of Taї National Park in Ivory Coast. Macroscopic tooth wear results from molar wear facets of the Liberian population indicate only slightly less wear when compared to the Taї population. This suggests similar long-term feeding behavior between both populations. In contrast, 3D surface texture results show that Liberian chimpanzees have many and small microscopic wear facet features that group them with those Taї chimpanzees that knowingly died during dry periods. This coincides with historical accounts, which indicate that local tribes poached and butchered the Liberian specimens during dust-rich dry periods. In addition, Liberian females and males differ somewhat in their 3D surface textures, with females having more microscopic peaks, smaller hill and dale areas and slightly rougher wear facet surfaces than males. This suggests a higher consumption of insects in Liberian females compared to males, based on similar 3D surface texture patterns previously reported for Taї chimpanzees. Our study opens new options for uncovering details of feeding behaviors of chimpanzees and other living and fossil primates, with macroscopic tooth wear tracing the long-term dietary and environmental history of a single population and microscopic tooth wear addressing short-term changes (e.g. seasonality)