Sexual dimorphism in white South African crania

Original published work submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2016Sexual dimorphism is one of four critical factors assessed by forensic anthropologists when compiling biological profiles. The current study used geometric morphometric methods to analyse various aspects of sexual dimorphism in white South African crania to significantly contribute to current forensic standards for this underrepresented population. As edentulous crania are a major contributing factor to the low number of publications on white South African populations, the question arose as to how tooth loss affects cranial structures and the accuracy of sex and ancestry estimation. Two hundred and twenty nine crania were digitised using landmarks and sliding semilandmarks, both globally and for a number of cranial subsets. Although a number of effects were identified when the skull was analysed globally, only the maxillary alveolar ridges were significantly affected when subsets were analysed individually. As both upper facial height and palate shape were significantly altered by tooth loss, the effects of tooth loss on cranial structures and sex and ancestry estimations were investigated. Next, to parse out the mechanisms by which sexual dimorphism causes morphological variation, overall sexual dimorphism, common allometry and nonallometric sexual dimorphism were individually assessed. Global and subset data were studied and the effects of sexual dimorphism and allometry were found to be universal, with significant differences being observed between the sexes both globally and regionally. A significant non-allometric component was, however, only found to contribute to the shape of the zygomatic bone. Finally, the accuracy of 17 widely used traditional cranial measurements was compared to all possible interlandmark distances (ILDs) attainable from 45 fixed landmarks. Discriminant functions derived using the ILDs compared well to those of previous work on white South Africans, thus demonstrating the similarity between traditional and 3-D methods. Finally, custom discriminant functions were created for a number of cranial subsets and for the cranium in its entirety. The subsets achieved sexing accuracies ranging between 71.8% and 83.7%, with the nasomaxilla proving most accurate. The overall cranial function attained a cross-validated sexing accuracy of 88.2%. These functions are critical for sex estimation not only for intact crania, but also for the innumerable fragmentary cranial remains recovered regularly in South Africa.MT201

Spanish Missionization and Maya Social Structure: Skeletal Evidence for Labor Distribution at Tipu, Belize

The cultural and human biological outcomes of Spanish colonization of the Americas were diverse. This dissertation examines the effects of Spanish colonization on Maya social structure using skeletal evidence for the distribution of labor at Tipu, a mission site in west central Belize. Skeletal remains of indigenous Maya buried in the context of a church, and in accordance with European Catholic burial customs, were examined for enthesis development and the cross-sectional morphology (CSG) of upper and lower limb long bones. Nothing besides burial placement in relation to the church (inside or outside the walls) denotes social status among individuals. Bone functional adaptations were used to examine the distribution of labor at Tipu and determine whether activity patterns varied by burial placement, and therefore social status. The bone functional adaptations of samples of pre-contact Maya elite and non-elites were also examined to determine whether the activity patterns of high and low status individuals at Tipu varied in the same way as those of Classic/Postclassic Maya of different social tiers. A 3D laser scanner was used to measure the surface areas of entheses on the humerus, radius and ulna, as well as CSG of the humerus (at 35% of length), femur and tibia (at midshaft). Detailed in this dissertation are: 1) a pilot study testing the reliability of the new 3D method for quantifying enthesis development, 2) an investigation of the distribution of labor at Tipu using entheses as indicators of habitual upper limb muscle use, and 3) an investigation of labor distribution at Tipu using CSG as indication of habitual upper limb use and mobility patterns. The pilot study presented in Chapter 2 supports the use of the 3D method for quantifying enthesis development. Chapters 3 and 4 demonstrate that both patterns of enthesis development and CSG at Tipu suggest Maya social structure changed with missionization. The activity patterns of high and low status individuals did not replicate those of pre-contact elites and non-elites. In general, the activity patterns of Tipuans of different social status were more similar. There were no drastic differences in the bone functional adaptations of inside and outside burial groups. However, some notable exceptions to this finding in both enthesis development and CSG suggest there may have been some task specialization among higher status Tipu men and women

Assessment of #TheDress With Traditional Color Vision Tests: Perception Differences Are Associated With Blueness

Based on known color vision theories, there is no complete explanation for the perceptual dichotomy of #TheDress in which most people see either white-and-gold (WG) or blue-and-black (BK). We determined whether some standard color vision tests (i.e., color naming, color matching, anomaloscope settings, unique white settings, and color preferences), as well as chronotypes, could provide information on the color perceptions of #TheDress. Fifty-two young observers were tested. Fifteen of the observers (29%) reported the colors as BK, 21 (40%) as WG, and 16 (31%) reported a different combination of colors. Observers who perceived WG required significantly more blue in their unique white settings than those who perceived BK. The BK, blue-and-gold, and WG observer groups had significantly different color preferences for the light cyan chip. Moreland equation anomaloscope matching showed a significant difference between WG and BK observers. In addition, #TheDress color perception categories, color preference outcomes, and unique white settings had a common association. For both the bright and dark regions of #TheDress, the color matching chromaticities formed a continuum, approximately following the daylight chromaticity locus. Color matching to the bright region of #TheDress showed two nearly distinct clusters (WG vs. BK) along the daylight chromaticity locus and there was a clear cutoff for reporting WG versus BK. All results showing a significant difference involved blue percepts, possibly due to interpretations of the illuminant interactions with the dress material. This suggests that variations in attributing blueness to the #TheDress image may be significant variables determining color perception of #TheDress.Fil: Feitosa-Santana, Claudia. Universidade Federal do ABC; BrasilFil: Lutze, Margaret. Depaul University; Estados UnidosFil: Barrionuevo, Pablo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; ArgentinaFil: Cao, Dingcai. University of Illinois; Estados Unido

Permutation entropy and its main biomedical and econophysics applications: a review

Entropy is a powerful tool for the analysis of time series, as it allows describing the probability distributions of the possible state of a system, and therefore the information encoded in it. Nevertheless, important information may be codified also in the temporal dynamics, an aspect which is not usually taken into account. The idea of calculating entropy based on permutation patterns (that is, permutations defined by the order relations among values of a time series) has received a lot of attention in the last years, especially for the understanding of complex and chaotic systems. Permutation entropy directly accounts for the temporal information contained in the time series; furthermore, it has the quality of simplicity, robustness and very low computational cost. To celebrate the tenth anniversary of the original work, here we analyze the theoretical foundations of the permutation entropy, as well as the main recent applications to the analysis of economical markets and to the understanding of biomedical systems.Facultad de Ingenierí

Wearable Sensors in the Evaluation of Gait and Balance in Neurological Disorders

The aging population and the increased prevalence of neurological diseases have raised the issue of gait and balance disorders as a major public concern worldwide. Indeed, gait and balance disorders are responsible for a high healthcare and economic burden on society, thus, requiring new solutions to prevent harmful consequences. Recently, wearable sensors have provided new challenges and opportunities to address this issue through innovative diagnostic and therapeutic strategies. Accordingly, the book “Wearable Sensors in the Evaluation of Gait and Balance in Neurological Disorders” collects the most up-to-date information about the objective evaluation of gait and balance disorders, by means of wearable biosensors, in patients with various types of neurological diseases, including Parkinson’s disease, multiple sclerosis, stroke, traumatic brain injury, and cerebellar ataxia. By adopting wearable technologies, the sixteen original research articles and reviews included in this book offer an updated overview of the most recent approaches for the objective evaluation of gait and balance disorders

Skeletal sexing standards of human remains in Turkey

The identification of victims involved in mass fatality incidents, as well as the identification of unknown individuals in criminal cases has become an increasingly important issue nowadays. Sex assessment represents a key point in forensic evaluations due to its significance in providing biological identity. Even though the availability of documented skeletal remains to forensic practitioners is a common practice in many countries, in Turkey, contemporary documented skeletal remains are not available for this purpose. For this reason, studies have been focused on living populations. Previous research has shown that modern technologies such as CT scanning present very promising potential in establishing new standards for contemporary populations. Therefore, the main aim of this project was to examine the application of the measurements taken from 3D CT images of the femur in order to assess sex, and to contribute to the establishment of discriminant function equations for the Turkish population for forensic applications. The accuracy and reproducibility of imaging methods in the assessment of the measurements taken from femora are essential when estimating sex. This research also concentrated on determining the accuracy and repeatability of CT measurements, using the femur. Prior to primary data collection, a preliminary study was performed in an effort to test the reliability of the femur measurements. The results of reliability analysis indicated no significant difference between the three observations of each measurement. Thus, the methodology employed in the current study appears reliable and reproducible. In addition, a validation study was conducted to determine the linear measurement accuracy of the 3D volume rendering models derived from a medical CT scanner and the influence of different reconstruction parameters. The differences between measurements obtained from dry bones and their 3D volume rendered models were also evaluated. The results from this study indicated that there were no statistically significant differences between measurements taken from different reconstruction parameters and measurements obtained from CT images and drybones. Using the CT data, volume-rendering function (VR), 3D Curved Multiplanar reconstruction (MPR), and Scout View on OsiriX were employed in order to compare the accuracy and reliability of each rendering method and to determine which technique is optimal for linear measurements. Overall, the measurements taken from the 3D Volume Rendering images had the highest intra-observer reliability when compared to the other two rendering methods. This research study produced data and interpretations that will inform on and improve population specific standards of sex assessment from three-dimensional postcranial osteometric landmarks. Additionally, this research is believed to provide value for a developing discipline of forensic anthropology, and integrate within the existing systems of criminal investigation and disaster victim identification practices in Turkey. A Turkish sample population, consisting of 300 adult hospital patients was examined via the interpretation of CT reconstructed images using the OsiriX software. The 3D reconstructions were then created using the volume-rendering function in OsiriX (v.5.6.). Following the 3D reconstruction, an image of each femur was segmented from the surrounding bones to ensure the correct usage of landmarks as accurately as possible. Thirteen measurements were acquired using a 3D viewer after being located and marked on each CT reconstructed femora. These thirteen anthropometric parameters were measured and analysed by basic descriptive statistics and discriminant analysis methods using the SPSS 21.0 software package. The intra-observer variation was assessed by obtaining the intraclass correlation coefficient in order to evaluate the accuracy of the linear measurements taken. Asymmetry was also tested. The results indicated that an accuracy of 92.3% was acquired from a combination of six of the measurements, and the Femur Vertical Diameter of Neck (FVDN) measurement was found to be the most dimorphic with 88.0% accuracy

Informed Clinical Management of Acute Stroke: Use of Established Statistical Methods and Development of an Expert System

This thesis applies several statistical techniques which aim to provide informed clinical management in acute stroke. An introduction is given to issues arising in stroke management and expert systems methodology. Three linear discriminant scoring systems (the Allen, Siriraj and Besson scores) intended for the differential diagnosis between ischaemic and haemorrhagic stroke on the basis of clinical presentation are evaluated in chapter 2. Chapter 3 explores whether angiotensin converting enzyme DD genotype is a risk factor for acute stroke or influences stroke outcome as measured by lesion size. Chapters 4 and 5 assess computed tomography, mean cerebral transit time and single-photon emission computed tomography scanning in terms of their accuracy in predicting functional outcome after acute ischaemic stroke. Chapter 6 broadens the search for prognostic factors, looking at the performance of the Guy's prognostic score and established neurological scales (Canadian neurological scale, National Institutes of Health stroke scale, middle cerebral artery neurological scale) in predicting acute stroke outcome. A linear discriminant score, based on simple clinical measurements recorded in the acute stroke unit, is also developed. Chapter 7 looks specifically at the influence of plasma glucose level on survival following acute stroke, after adjusting for other known prognostic factors using Cox's proportional hazards regression model. The remainder of the thesis is concerned with two aspects of acute stroke management. The first of these is the selection of an appropriate clinical trial for an individual patient. A computer program is developed to obtain, in an efficient manner, the information required to check the entry and exclusion criteria for each available clinical trial. The second aspect of stroke management considered is the choice of a suitable method for secondary prevention of stroke in individual acute ischaemic stroke patients. Candidate methods are long-term anticoagulation with warfarin, or aspirin antiplatelet therapy. Expert system methodology is used to combine positive indications for, and contraindications to each of these therapies with clinical data available in the acute stroke unit. The annual risks of recurrent ischaemic stroke, haemorrhagic stroke, myocardial infarction, other ischaemic complications and other haemorrhagic complications are estimated to allow an informed decision on the appropriate method of secondary prevention to be made

Foot, ankle and lower limb somatosensory dysfunction in stroke

The extent to which sensory impairments in the foot, ankle and lower limb persist into the chronic phase of stroke is unclear. Furthermore, the extent to which these impairments influence walking, balance and falls is not well understood. This thesis investigated the prevalence, functional importance and measurement of lower limb somatosensory impairments in ambulatory people with chronic stroke. Methods This thesis comprised three studies: the first, a qualitative investigation, explored the views and experiences of people with chronic stroke (n=13). This led to the second study: a cross sectional observational study in which the prevalence, distribution and functional relevance of lower limb sensory impairments were investigated in chronic stroke participants (n=180) and healthy controls (n=46). The final study, informed by the findings from the first two studies, a “synthesis” review of current sensory measures and patient and carer involvement, developed and evaluated three novel, functionally oriented measures of lower limb somatosensory discrimination in chronic stroke (n=32) and healthy controls (n=32). Results People with stroke felt problems with foot, ankle and lower limb sensation affected their walking, balance and contributed to falls. Furthermore, sensory impairments in the lower limb are prevalent with up to 59% of chronic stroke survivors having a deficit of one or more somatosensory modality. Despite this, weak associations between traditional measures of tactile and proprioceptive sensation and walking, balance and falls were demonstrated. Novel, functionally oriented measures of tactile and proprioceptive discrimination were developed and evaluated. These measures were reliable and valid, showing greater sensitivity to predicting the presence of sensory impairments and had stronger associations with functional measures than traditional sensory tests. Conclusions This thesis has provided a comprehensive picture of lower limb somatosensory dysfunction in chronic stroke survivors. Sensory impairments persist into the chronic phase of stroke in the majority of stroke survivors. The extent to which such impairments influence functional ability warrants further investigation. The use of functionally oriented measures that assess higher-level somatosensation is encouraged.Chartered Society of PhysiotherapyDr William Scholl Podiatric Research and Development Fun